Processing system and processing method

Abstract

This processing system comprises: a processing device that forms a molten pool on an object through irradiation of the object with an energy beam, and feeds a building material to the molten pool to process the object; an imaging device that can generate a molten pool image by capturing an image of the molten pool; and a control device that generates molten pool image information on the basis of the molten pool image, and controls the processing device such that the size of a molten pool region is a target size on the basis of the molten pool image information. The molten pool image information is generated on the basis of a plurality of molten pool images. The control device changes an imaging condition for the imaging device to capture an image of the molten pool, on the basis of a processing condition of the object.

Description

Processing system and processing method

[0001] The present invention relates to the technical field of a processing system and a processing method capable of processing an object, for example.

[0002] An example of a processing system for processing an object is described in Patent Document 1. One of the technical challenges of such a processing system is to process the object appropriately.

[0003] US Patent Application Publication No. 2016 / 0311059

[0004] According to a first aspect, a processing system is provided that includes a processing device that forms a molten pool on an object by irradiating the object with an energy beam and processes the object by supplying a building material to the molten pool; an imaging device that can generate a molten pool image by imaging the molten pool; and a control device that generates molten pool image information based on the molten pool image generated by the imaging device and controls the processing device so that the size of the molten pool area becomes a target size based on the molten pool image information, wherein the molten pool image information is generated based on a plurality of molten pool images captured by the imaging device, and the control device changes the imaging conditions for the imaging device to image the molten pool based on the processing conditions of the object by the processing device.

[0005] According to a second aspect, there is provided a processing system comprising: a processing head that irradiates an object with an energy beam to form a molten pool on the object and processes the object by supplying a building material to the molten pool; a position change device that can change the irradiation position of the energy beam relative to the processing head; an imaging device that is attached to the processing head and is capable of generating a molten pool image by imaging the molten pool formed by the processing device; and a control device that generates molten pool image information based on the molten pool image generated by the imaging device and controls the processing device based on the molten pool image information so that the size of the molten pool area becomes a target size, wherein the molten pool image information is generated based on a plurality of molten pool images captured by the imaging device.

[0006] According to a third aspect, a processing system is provided which includes a processing device that forms a molten pool on an object by irradiating the object with an energy beam and processes the object by supplying a molding material to the molten pool, an imaging device that can generate a molten pool image by imaging the molten pool, and a control device that calculates the size of a molten pool area in the molten pool image based on the result of comparing the signal value of the molten pool image with a predetermined threshold and controls the processing device so that the size of the molten pool area becomes a target size, and the control device changes the predetermined threshold based on the processing conditions of the object by the processing device.

[0007] According to a fourth aspect, a processing system is provided that includes a processing device that forms a molten pool on an object by irradiating the object with an energy beam and processes the object by supplying a molding material to the molten pool, an imaging device that can generate a molten pool image by imaging the molten pool, and a control device that generates molten pool image information based on the molten pool image generated by the imaging device and controls the processing device based on the molten pool image information so that the size of the molten pool area becomes a target size, and the control device changes the target size based on the processing conditions of the object by the processing device.

[0008] According to a fifth aspect, a processing system is provided that includes a processing device that forms a molten pool on an object by irradiating the object with an energy beam and processes the object by supplying a molding material to the molten pool, an imaging device that can generate multiple images by capturing multiple images of an area including the molten pool, and a control device that adds up the signal values ​​for each pixel of the multiple images and, based on the result of comparing the addition result for each pixel with a predetermined threshold, detects at least one of a molten pool area in the image and a non-molten pool area in which at least one of emitted light and reflected light other than the molten pool is captured.

[0009] According to a sixth aspect, a processing system is provided that includes a processing device that forms a molten pool on an object by irradiating the object with an energy beam and processes the object by supplying a molding material to the molten pool, an imaging device that is capable of multiple exposure of an area including the molten pool, and a control device that detects at least one of a molten pool area in an image generated by the multiple exposure and a non-molten pool area in which at least one of emitted light and reflected light other than the molten pool is captured by comparing the results of the multiple exposure by the imaging device with a predetermined threshold.

[0010] According to a seventh aspect, a processing system is provided, comprising: a processing device that forms a molten pool on an object by irradiating the object with an energy beam and processes the object by supplying a molding material to the molten pool; an imaging device that can generate a molten pool image by imaging the molten pool; a control device that generates molten pool image information based on the molten pool image generated by the imaging device and controls the processing device based on the molten pool image information so that the size of the molten pool area becomes a target size; and a recording device that records information regarding the target size of the molten pool in association with the wobble conditions of the energy beam, wherein the control device controls the processing device based on the target size of the molten pool obtained from the recording device.

[0011] According to an eighth aspect, a processing system is provided which includes a processing device that forms a molten pool on an object by irradiating the object with an energy beam and processes the object by supplying a molding material to the molten pool, an imaging device that can generate a molten pool image by imaging the molten pool, and a control device, wherein the control device can acquire shape information regarding the molten pool formed continuously at different positions by the energy beam based on the molten pool image generated by the imaging device, and controls the processing device based on the shape information.

[0012] According to a ninth aspect, a processing system is provided which includes a processing device that forms a molten pool on an object by irradiating the object with an energy beam and processes the object by supplying a molding material to the molten pool, an imaging device that can generate a molten pool image by imaging the molten pool, and a control device, wherein the control device can acquire center position information of molten pools that are continuously formed at different positions by the energy beam based on the molten pool image generated by the imaging device, and controls the processing device based on the center position information.

[0013] According to a tenth aspect, a processing system is provided which includes a processing device that forms a molten pool on an object by irradiating the object with an energy beam and processes the object by supplying a building material to the molten pool, an imaging device that can generate a molten pool image by imaging the molten pool, and a control device that generates molten pool image information based on the molten pool image generated by the imaging device and controls the processing device so that the size of the molten pool area becomes a target size based on the molten pool image information, wherein the molten pool image information is generated based on the molten pool image generated by multiple exposure by the imaging device, and the control device changes the conditions of the multiple exposure by the imaging device based on the processing conditions of the object by the processing device.

[0014] According to an eleventh aspect, there is provided a processing system comprising: a processing head that irradiates an object with an energy beam to form a molten pool on the object and processes the object by supplying a molding material to the molten pool; a position change device that can change the irradiation position of the energy beam relative to the processing head; an imaging device that is attached to the processing head and is capable of generating a molten pool image by imaging the molten pool formed by the processing device; and a control device that generates molten pool image information based on the molten pool image generated by the imaging device and controls the processing device based on the molten pool image information so that the size of the molten pool area becomes a target size, wherein the molten pool image information is generated based on multiple exposure by the imaging device.

[0015] According to a twelfth aspect, there is provided a processing system comprising: a processing device that irradiates an object with an energy beam to form a molten pool on the object; an imaging device that can generate a molten pool image by imaging the molten pool; and a control device that generates molten pool image information based on the molten pool image generated by the imaging device and controls the processing device based on the molten pool image information, wherein the molten pool image information is generated based on a plurality of molten pool images captured by the imaging device, and the control device changes the imaging conditions for the imaging device to image the molten pool based on the processing conditions of the object by the processing device.

[0016] According to a thirteenth aspect, there is provided a processing system comprising: a processing device having a processing head that processes an object by irradiating the object with an energy beam to form a molten pool on the object; a position changing device that can change the irradiation position of the energy beam relative to the processing head; an imaging device that is attached to the processing head and can generate a molten pool image by imaging the molten pool formed by the processing device; and a control device that generates molten pool image information based on the molten pool image generated by the imaging device and controls the processing device based on the molten pool image information.

[0017] According to a fourteenth aspect, a processing system is provided which includes a processing device that processes an object by irradiating the object with an energy beam to form a molten pool on the object, an imaging device that can generate a molten pool image by imaging the molten pool, and a control device that controls the processing device based on the result of comparing the signal value of the molten pool image with a predetermined threshold, and the control device changes the predetermined threshold based on the processing conditions of the object by the processing device.

[0018] According to the 15th aspect, there is provided a processing system comprising a processing device that processes an object by irradiating the object with an energy beam to form a molten pool on the object, an imaging device that can generate a molten pool image by imaging the molten pool, and a control device that generates molten pool image information based on the molten pool image generated by the imaging device and controls the processing device based on the molten pool image information so that the size of the molten pool area becomes a target size, wherein the control device changes the target size based on the processing conditions of the object by the processing device.

[0019] According to a sixteenth aspect, there is provided a processing system comprising: a processing device that processes an object by irradiating the object with an energy beam to form a molten pool on the object; an imaging device that can generate multiple images by capturing multiple images of an area including the molten pool; and a control device that detects at least one of a molten pool area in the image and a non-molten pool area that includes at least one of emitted light and reflected light other than the molten pool based on the sum of signal values ​​for each pixel of the multiple images.

[0020] According to the seventeenth aspect, there is provided a processing system comprising: a processing device that processes an object by irradiating the object with an energy beam to form a molten pool on the object; an imaging device that can perform multiple exposures of an area including the molten pool; and a control device that detects at least one of a molten pool area in an image generated by the multiple exposure and a non-molten pool area in which at least one of emitted light and reflected light other than the molten pool is captured based on the results of the multiple exposures performed by the imaging device and a predetermined threshold value.

[0021] According to the 18th aspect, there is provided a processing system comprising: a processing device that processes an object by irradiating the object with an energy beam to form a molten pool on the object; an imaging device that can generate a molten pool image by imaging the molten pool; a control device that generates molten pool image information based on the molten pool image generated by the imaging device and controls the processing device based on the molten pool image information; and a recording device that records information regarding the target size of the molten pool in association with the wobble conditions of the energy beam, wherein the control device controls the processing device based on the target size of the molten pool obtained from the recording device.

[0022] According to a 19th aspect, a processing system is provided which includes a processing device that processes an object by irradiating the object with an energy beam to form a molten pool on the object, an imaging device that can generate a molten pool image by imaging the molten pool, and a control device, wherein the control device can acquire shape information regarding the molten pool that is continuously formed at different positions by the energy beam based on the molten pool image generated by the imaging device, and controls the processing device based on the shape information.

[0023] According to the twentieth aspect, a processing system is provided which includes a processing device that processes an object by irradiating the object with an energy beam to form a molten pool on the object, an imaging device that can generate a molten pool image by imaging the molten pool, and a control device, wherein the control device can acquire center position information of the molten pool that is continuously formed at different positions by the energy beam based on the molten pool image generated by the imaging device, and controls the processing device based on the center position information.

[0024] According to a 21st aspect, there is provided a processing system comprising: a processing device that processes an object by irradiating the object with an energy beam to form a molten pool on the object; an imaging device that can generate a molten pool image by imaging the molten pool; and a control device that generates molten pool image information based on the molten pool image generated by the imaging device and controls the processing device based on the molten pool image information, wherein the molten pool image information is generated based on the molten pool image generated by multiple exposure by the imaging device, and the control device changes the conditions of the multiple exposure by the imaging device based on the processing conditions of the object by the processing device.

[0025] According to the 22nd aspect, there is provided a processing system comprising: a processing device including a processing head that processes an object by irradiating the object with an energy beam to form a molten pool on the object; a position change device that can change the irradiation position of the energy beam relative to the processing head; an imaging device that is attached to the processing head and is capable of generating a molten pool image by imaging the molten pool formed by the processing device; and a control device that generates molten pool image information based on the molten pool image generated by the imaging device and controls the processing device based on the molten pool image information, wherein the molten pool image information is generated based on multiple exposure by the imaging device.

[0026] According to a 23rd aspect, there is provided a processing system comprising: a processing device that forms a molten pool on an object by irradiating the object with an energy beam and forms a structure on the object along a target trajectory; an imaging device that can generate a molten pool image by imaging the molten pool; and a control device that controls the processing device based on the molten pool image generated by the imaging device, wherein forming the structure on the object along the target trajectory includes moving the irradiation position of the energy beam on the surface of the object along a scanning direction that intersects with the target trajectory, and the control device controls the processing device based on a plurality of the molten pool images imaged by the imaging device.

[0027] According to the 24th aspect, a processing system is provided which includes a processing device that forms a molten pool on an object by irradiating the object with an energy beam, and an imaging device that can generate a molten pool image by imaging the molten pool, wherein the imaging device is capable of imaging a molten pool that appears at a first position at a first time and a molten pool that appears at a second position different from the first position at a second time different from the first time.

[0028] The functions and other advantages of the present invention will become apparent from the following detailed description of the preferred embodiments.

[0029] FIG. 1 is a cross-sectional view showing the configuration of a processing system according to this embodiment. FIG. 2 is a block diagram showing the configuration of the processing system according to this embodiment. FIG. 3 is a perspective view showing the structure of an irradiation optical system. FIG. 4(a) is a plan view showing the movement trajectory of a target irradiation area within a processing unit area, and FIG. 4(b) is a plan view showing the movement trajectory of a target irradiation area on a printing surface. FIGS. 5(a) and 5(b) are plan views showing the movement trajectory of a target irradiation area within a processing unit area, and FIG. 5(c) is a plan view showing the movement trajectory of a target irradiation area on a printing surface. FIGS. 6(a) to 6(e) are cross-sectional views showing a state in which a processing light is irradiated onto a certain area on a workpiece and a printing material is supplied. FIG. 7(a) is a plan view showing the target movement trajectory of a processing unit area, and FIG. 7(b) is a plan view showing a linear object to be printed on the printing surface when the processing unit area moves along the target movement trajectory shown in FIG. 7(a). FIGS. 8(a) to 8(c) are cross-sectional views showing the process of forming a three-dimensional structure. FIG. 9 is a flowchart showing the flow of weld pool feedback control operation based on weld pool images. FIG. 10 shows a weld pool image. FIG. 11 shows an additive image generated by adding (i.e., compositing) multiple weld pool images. FIG. 12 is a timing chart showing the relationship between the size of the weld pool area and the target size. FIG. 13 shows a weld pool image in which weld pool areas and non-weld pool areas are captured. FIG. 14 shows multiple weld pool images. FIG. 15 shows an additive image generated by adding (i.e., compositing) the multiple weld pool images shown in FIG. 14. FIG. 16(a) is a timing chart showing the imaging timing of the imaging unit, FIG. 16(b) is a timing chart showing the exposure time of the imaging unit, and FIG. 16(c) is a timing chart showing the imaging period and imaging rate of the imaging unit. 17 shows a histogram of brightness values ​​in the molten pool image when the machining light intensity is a first intensity, and a histogram of brightness values ​​in the molten pool image when the machining light intensity is a second intensity. FIG. 18 shows a histogram of brightness values ​​in the molten pool image when the machining light intensity is a first intensity, and a histogram of brightness values ​​in the molten pool image when the machining light intensity is a second intensity.Figure 19 shows a histogram of brightness values ​​in the weld pool image when the target irradiation area moves at a first speed and a histogram of brightness values ​​in the weld pool image when the target irradiation area moves at a second speed. Figure 20 shows a histogram of brightness values ​​in the weld pool image when the target irradiation area moves at a first speed and a histogram of brightness values ​​in the weld pool image when the target irradiation area moves at a second speed. Figure 21(a) shows a histogram of brightness values ​​in the weld pool image when the machining light intensity is a first intensity, Figure 21(b) shows a histogram of brightness values ​​in the weld pool image when the machining light intensity is a second intensity and the number of added frames is not changed, and Figure 21(c) shows a histogram of brightness values ​​in the weld pool image when the machining light intensity is the second intensity and the number of added frames is changed. Fig. 22(a) shows a histogram of brightness values ​​in the weld pool image when the machining light intensity is a first intensity, Fig. 22(b) shows a histogram of brightness values ​​in the weld pool image when the machining light intensity is a second intensity and the number of added frames is not changed, Fig. 22(c) shows a histogram of brightness values ​​in the weld pool image when the machining light intensity is the second intensity and the number of added frames is changed, Fig. 23(a) shows a histogram of brightness values ​​in the weld pool image when the target irradiation area moves at a first speed, Fig. 23(b) shows a histogram of brightness values ​​in the weld pool image when the target irradiation area moves at a second speed and the number of added frames is not changed, and Fig. 23(c) shows a histogram of brightness values ​​in the weld pool image when the target irradiation area moves at a second speed and the number of added frames is changed Fig. 24(a) shows a histogram of brightness values ​​in the molten pool image when the speed of movement of the target irradiation area is a first speed, Fig. 24(b) shows a histogram of brightness values ​​in the molten pool image when the speed of movement of the target irradiation area is a second speed and the number of added frames is not changed, and Fig. 24(c) shows a histogram of brightness values ​​in the molten pool image when the speed of movement of the target irradiation area is the second speed and the number of added frames is changed. Fig. 25 is a timing chart showing the relationship between the size of the molten pool area and the target size.Figures 26(a) and 26(b) show the shape of the weld pool region. Figures 27(a) and 27(b) are cross-sectional views showing a linear object formed when the weld pool region shown in Figure 26(a) is detected, and Figures 27(c) and 27(d) are cross-sectional views showing a linear object formed when the weld pool region shown in Figure 26(b) is detected. Figure 28(a) shows the movement trajectory of the weld pool region. Figure 28(b) is a cross-sectional view showing a linear object formed when the weld pool region shown in Figure 28(a) is detected. Figure 28(c) shows the movement trajectory of the weld pool region. Figure 28(d) is a cross-sectional view showing a linear object formed when the weld pool region shown in Figure 28(c) is detected. Figure 28(e) shows the movement trajectory of the weld pool region. Figure 29 is a cross-sectional view showing the center position of the weld pool region during the process of laminating multiple linear objects.

[0030] Hereinafter, embodiments of a processing system and a processing method will be described with reference to the drawings. Hereinafter, embodiments of a processing device and a processing method will be described using a processing system SYS capable of processing a workpiece W, which is an example of an object. In particular, below, embodiments of a processing device and a processing method will be described using a processing system SYS that performs additive processing based on laser metal deposition (LMD). Additional processing based on laser metal deposition is additive processing that forms a shaped object that is integrated with the workpiece W or that can be separated from the workpiece W by melting a shaping material M supplied to the workpiece W with processing light EL (i.e., an energy beam in the form of light).

[0031] In the following description, the positional relationships of the various components constituting the machining system SYS will be described using an XYZ Cartesian coordinate system defined by mutually orthogonal X, Y, and Z axes. For convenience of explanation, the X-axis and Y-axis directions are each assumed to be horizontal (i.e., a predetermined direction within a horizontal plane), and the Z-axis direction is assumed to be vertical (i.e., a direction perpendicular to the horizontal plane, essentially an up-down direction). Furthermore, the rotation directions around the X-axis, Y-axis, and Z-axis (in other words, tilt directions) are referred to as the θX direction, θY direction, and θZ direction, respectively. Here, the Z-axis direction may be the direction of gravity. Furthermore, the XY plane may be assumed to be horizontal.

[0032] (1) Configuration of the machining system SYS (1-1) Overall configuration of the machining system SYS First, the configuration of the machining system SYS of this embodiment will be described with reference to Figures 1 and 2. Figure 1 is a cross-sectional view that schematically shows the configuration of the machining system SYS of this embodiment. Figure 2 is a block diagram that shows the configuration of the machining system SYS of this embodiment.

[0033] The machining system SYS is capable of performing additive processing on the workpiece W. By performing additive processing on the workpiece W, the machining system SYS is capable of forming a shaped object that is integrated with (or separable from) the workpiece W. In this case, the additional processing performed on the workpiece W corresponds to processing that adds, to the workpiece W, a shaped object that is integrated with (or separable from) the workpiece W. Note that the shaped object in this embodiment may refer to any object that the machining system SYS forms. For example, the machining system SYS is capable of forming a three-dimensional structure ST (that is, a three-dimensional structure that has a size in all three-dimensional directions, a solid object, in other words, a structure that has a size in the X-axis direction, Y-axis direction, and Z-axis direction) as an example of a shaped object.

[0034] When the workpiece W is a stage 31 described below, the processing system SYS is capable of performing additional processing on the stage 31. When the workpiece W is a mounted object, which is an object placed on the stage 31, the processing system SYS is capable of performing additional processing on the mounted object. The mounted object placed on the stage 31 may be another three-dimensional structure ST (i.e., an existing structure) formed by the processing system SYS. Note that FIG. 1 shows an example in which the workpiece W is an existing structure placed on the stage 31. Also, the following description will be given using an example in which the workpiece W is an existing structure placed on the stage 31.

[0035] The workpiece W may be a product that has a missing portion and needs to be repaired. In this case, the machining system SYS may perform repair processing to repair the product that needs to be repaired by performing additional processing to form a shaped object to fill the missing portion. In other words, the additional processing performed by the machining system SYS may include additional processing to add a shaped object to the workpiece W to fill the missing portion.

[0036] As described above, the processing system SYS is capable of performing additive processing based on the laser buildup welding method. In other words, the processing system SYS can also be said to be a 3D printer that processes an object using additive manufacturing technology. Note that additive manufacturing technology may also be referred to as rapid prototyping, rapid manufacturing, or additive manufacturing. Note that the laser buildup welding method (LMD) may also be referred to as directed energy deposition (DED).

[0037] A processing system SYS using additive manufacturing technology sequentially forms multiple structural layers SL (see FIG. 7 , described later) to form a three-dimensional structure ST in which multiple structural layers SL are stacked. In this case, the processing system SYS first sets the surface of the workpiece W as a printing surface MS on which the object is actually printed, and prints the first structural layer SL on the printing surface MS. The processing system SYS then sets the surface of the first structural layer SL as a new printing surface MS, and prints the second structural layer SL on the new printing surface MS. Thereafter, the processing system SYS repeats the same operations to form a three-dimensional structure ST in which multiple structural layers SL are stacked.

[0038] The processing system SYS performs additive processing by processing the modeling material M using processing light EL, which is an energy beam. The modeling material M is a material that can be melted by irradiation with processing light EL of a predetermined intensity or higher. For example, at least one of a metallic material and a resinous material can be used as the modeling material M. Examples of metallic materials include at least one of a material containing copper, a material containing tungsten, and a material containing stainless steel. However, materials other than metallic materials and resinous materials may also be used as the modeling material M. The modeling material M is a powdered material. In other words, the modeling material M is a powder. However, the modeling material M does not have to be a powder. For example, at least one of a wire-shaped modeling material and a gaseous modeling material may be used as the modeling material M.

[0039] Like the forming material M, the workpiece W may also be an object containing a material that can be melted by irradiation with processing light EL of a predetermined intensity or higher. The material of the workpiece W may be the same as or different from the forming material M. For example, at least one of a metallic material and a resinous material can be used as the material of the workpiece W. Examples of metallic materials include at least one of a material containing copper, a material containing tungsten, and a material containing stainless steel. However, materials other than metallic materials and resinous materials may also be used as the material of the workpiece W.

[0040] 1 and 2 , the processing system SYS includes a material supply source 1, a processing unit 2, a stage unit 3, a light source 4, a gas supply source 5, a control unit 7, and an imaging unit 8. The processing unit 2 and the stage unit 3 may be housed in a chamber space 63IN inside the housing 6. In this case, the processing system SYS may perform additional processing in the chamber space 63IN. Note that at least one of the processing unit 2 and the stage unit 3 does not have to be housed in the chamber space 63IN inside the housing 6.

[0041] The processing unit 2 may be referred to as a processing device. An apparatus including the processing unit 2 and at least one of the material supply source 1, the stage unit 3, the light source 4, and the gas supply source 5 may be referred to as a processing device. The control unit 7 may be referred to as a control device. The imaging unit 8 may be referred to as an imaging device.

[0042] The material supply source 1 supplies the processing unit 2 with the modeling material M. The material supply source 1 supplies a desired amount of modeling material M according to the required amount so that the amount of modeling material M required per unit time for performing additive processing is supplied to the processing unit 2.

[0043] The processing unit 2 processes the modeling material M supplied from the material supply source 1 to form a model. To form the model, the processing unit 2 includes a processing head 21 and a head drive system 22. The processing head 21 further includes an irradiation optical system 211 and a plurality of material nozzles 212. However, the processing head 21 may include a plurality of irradiation optical systems 211. The processing head 21 may also include a single material nozzle 212.

[0044] The irradiation optical system 211 is an optical system for emitting the processing light EL. Specifically, the irradiation optical system 211 is optically connected to the light source 4 that emits (generates) the processing light EL via a light transmission member 41. An example of the light transmission member 41 is at least one of an optical fiber and a light pipe.

[0045] In the example shown in Figures 1 and 2, the processing system SYS includes two light sources 4 (specifically, light sources 4#1 and 4#2), and the irradiation optical system 211 is optically connected to the light sources 4#1 and 4#2 via optical transmission members 41#1 and 41#2, respectively. The irradiation optical system 211 emits both the processed light EL propagating from the light source 4#1 via the optical transmission member 41#1 and the processed light EL propagating from the light source 4#2 via the optical transmission member 41#2. In the following description, when it is necessary to distinguish between the two processed light beams EL emitted by the irradiation optical system 211, the processed light EL generated by the light source 4#1 will be referred to as "processed light EL#1" and the processed light EL generated by the light source 4#2 will be referred to as "processed light EL#2."

[0046] However, the processing system SYS may include a single light source 4 instead of the multiple light sources 4. The irradiation optical system 211 may emit a single processing light EL instead of emitting multiple processing light EL.

[0047] The irradiation optical system 211 emits the processing light EL downward (i.e., toward the -Z side). A stage 31 is disposed below the irradiation optical system 211. When a workpiece W is placed on the stage 31, the irradiation optical system 211 irradiates the emitted processing light EL onto the printing surface MS. Specifically, the irradiation optical system 211 can irradiate the processing light EL onto a target irradiation area (target irradiation position) EA that is set on the printing surface MS as an area to be irradiated (typically, focused) with the processing light EL. In the following description, when it is necessary to distinguish between two target irradiation areas EA onto which the irradiation optical system 211 respectively irradiates two processing light beams EL, the target irradiation area EA onto which the irradiation optical system 211 irradiates processing light EL#1 will be referred to as the "target irradiation area EA#1," and the target irradiation area EA onto which the irradiation optical system 211 irradiates processing light EL#2 will be referred to as the "target irradiation area EA#2." Furthermore, the state of the irradiation optical system 211 can be switched between a state in which the processing light EL is irradiated onto the target irradiation area EA and a state in which the processing light EL is not irradiated onto the target irradiation area EA under the control of the control unit 7. The direction of the processing light EL emitted from the irradiation optical system 211 is not limited to being directly downward (i.e., coinciding with the -Z-axis direction) and may be, for example, a direction tilted by a predetermined angle with respect to the Z-axis. In other words, the third optical system 216 (or the fθ lens 2162) described later is not limited to being an optical system telecentric on the object side and may be an optical system non-telecentric on the object side.

[0048] The irradiation optical system 211 may form a molten pool MP on the printing surface MS by irradiating the printing surface MS with processing light EL. For example, the irradiation optical system 211 may form a molten pool MP#1 on the printing surface MS by irradiating the printing surface MS with processing light EL#1. For example, the irradiation optical system 211 may form a molten pool MP#2 on the printing surface MS by irradiating the printing surface MS with processing light EL#2. The molten pool MP#1 and the molten pool MP#2 may be integrated. Alternatively, the molten pool MP#1 and the molten pool MP#2 may be separated from each other. However, the molten pool MP#1 does not necessarily have to be formed on the printing surface MS by irradiating the printing surface MS with processing light EL#1. The molten pool MP#2 does not necessarily have to be formed on the printing surface MS by irradiating the printing surface MS with processing light EL#2.

[0049] The material nozzle 212 supplies (e.g., injects, jets, spouts, or sprays) the modeling material M. The material nozzle 212 is physically connected to the material supply source 1, which is a supply source of the modeling material M, via the supply pipe 11 and the mixer 12. The material nozzle 212 supplies the modeling material M supplied from the material supply source 1 via the supply pipe 11 and the mixer 12. The material nozzle 212 may pressure-feed the modeling material M supplied from the material supply source 1 via the supply pipe 11. That is, the modeling material M from the material supply source 1 and a conveying gas (i.e., a pressure-feed gas, for example, an inert gas such as nitrogen or argon) may be mixed in the mixer 12 and then pressure-feed to the material nozzle 212 via the supply pipe 11. As a result, the material nozzle 212 supplies the modeling material M together with the conveying gas. For example, a purge gas supplied from the gas supply source 5 is used as the conveying gas. However, the gas supplied from a gas supply source other than the gas supply source 5 may be used as the conveying gas. Although the material nozzle 212 is depicted as a tube in FIG. 1 , the shape of the material nozzle 212 is not limited to this. The material nozzle 212 supplies the modeling material M downward (i.e., toward the −Z side). The stage 31 is disposed below the material nozzle 212. When a workpiece W is mounted on the stage 31, the material nozzle 212 supplies the modeling material M toward the modeling surface MS. The direction of travel of the modeling material M supplied from the material nozzle 212 is inclined at a predetermined angle (for example, an acute angle) with respect to the Z-axis direction, but may also be toward the −Z side (i.e., directly downward).

[0050] In this embodiment, the material nozzle 212 supplies the building material M to a position where at least one of the processing lights EL#1 and EL#2 is irradiated (i.e., at least one of the target irradiation areas EA#1 and EA#2). For this reason, the material nozzle 212 and the irradiation optical systems 211#1 and 211#2 are aligned so that a target supply area MA, which is set on the building surface MS as an area where the material nozzle 212 supplies the building material M, at least partially overlaps with at least one of the target irradiation areas EA#1 and EA#2. The size of the target supply area MA may be larger, smaller, or the same as the size of at least one of the target irradiation areas EA#1 and EA#2.

[0051] The material nozzle 212 may supply the building material M to the molten pool MP. Specifically, the material nozzle 212 may supply the building material M to at least one of the molten pool MP#1 and the molten pool MP#2. However, the material nozzle 212 does not have to supply the building material M to the molten pool MP. For example, the processing system SYS may melt the building material M from the material nozzle 212 using processing light EL emitted from the irradiation optical system 211 before the building material M reaches the workpiece W, and then adhere the molten building material M to the workpiece W.

[0052] The irradiation optical system 211 and the material nozzle 212 may be housed in a head housing 213 provided in the processing head 21. The head housing 213 is a housing having an internal storage space for storing the irradiation optical system 211 and the material nozzle 212. In this case, the irradiation optical system 211 and the material nozzle 212 may be housed in the internal storage space of the head housing 213.

[0053] The head drive system 22 moves the machining head 21 under the control of the control unit 7. That is, the head drive system 22 moves the irradiation optical system 211 and the material nozzle 212 under the control of the control unit 7. The head drive system 22 moves the machining head 21, for example, along at least one of the X-axis direction, Y-axis direction, Z-axis direction, θX direction, θY direction, and θZ direction. Note that the operation of moving the machining head 21 along at least one of the θX direction, θY direction, and θZ direction may be considered equivalent to the operation of rotating the machining head 21 around at least one of the rotation axis along the X-axis, the rotation axis along the Y-axis, and the rotation axis along the Z-axis.

[0054] When the head drive system 22 moves the machining head 21, the relative positional relationship between the machining head 21 and the stage 31 and the workpiece W placed on the stage 31 changes. As a result, the relative positional relationship between the stage 31, the workpiece W, and the irradiation optical system 211 provided in the machining head 21 changes. For this reason, the head drive system 22 may be considered to function as a position changing device that can change the relative positional relationship between the stage 31, the workpiece W, and the irradiation optical system 211. Furthermore, when the relative positional relationship between the stage 31, the workpiece W, and the machining head 21 changes, the relative positional relationship between the target irradiation areas EA#1 and EA#2 and the target supply area MA and the workpiece W also changes. In other words, the target irradiation areas EA#1 and EA#2 and the target supply area MA each move along at least one of the X-axis direction, Y-axis direction, Z-axis direction, θX direction, θY direction, and θZ direction on the surface of the workpiece W (more specifically, the build surface MS on which additional machining is performed). In this case, it may be considered that the head drive system 22 moves the processing head 21 so that the target irradiation areas EA#1 and EA#2 and the target supply area MA each move on the printing surface MS.

[0055] The stage unit 3 includes a stage 31 and a stage drive system 32 .

[0056] The workpiece W is placed on the stage 31. Specifically, the workpiece W is placed on a stage placement surface 311, which is one surface of the stage 31 (e.g., the upper surface facing the +Z side). The stage 31 is capable of supporting the workpiece W placed on the stage 31. The stage 31 may be capable of holding the workpiece W placed on the stage 31. In this case, the stage 31 may be equipped with at least one of a mechanical chuck, an electrostatic chuck, a vacuum chuck, or the like to hold the workpiece W. Alternatively, the stage 31 may not be capable of holding the workpiece W placed on the stage 31. In this case, the workpiece W may be placed on the stage 31 in a clampless manner. Furthermore, the workpiece W may be attached to a holder, or the holder to which the workpiece W is attached may be placed on the stage 31. The above-mentioned irradiation optical system 211 emits each of the processing lights EL#1 and EL#2 during at least a portion of the period during which the workpiece W is placed on the stage 31. Furthermore, the material nozzle 212 described above supplies the modeling material M for at least a portion of the period during which the workpiece W is placed on the stage 31 .

[0057] The stage drive system 32 moves the stage 31. The stage drive system 32 moves the stage 31, for example, along at least one of the X-axis, Y-axis, Z-axis, θX direction, θY direction, and θZ direction. Note that the operation of moving the stage 31 along at least one of the θX direction, θY direction, and θZ direction may be considered equivalent to the operation of rotating the stage 31 around at least one of a rotation axis along the X-axis (i.e., A-axis), a rotation axis along the Y-axis (i.e., B-axis), and a rotation axis along the Z-axis (i.e., C-axis).

[0058] When the stage drive system 32 moves the stage 31, the relative positional relationships between the machining head 21 and the stage 31 and between the workpiece W and the irradiation optical system 211 provided in the machining head 21 change. As a result, the relative positional relationships between the stage 31, the workpiece W, and the irradiation optical system 211 provided in the machining head 21 change. For this reason, the stage drive system 32, like the head drive system 22, may be considered to function as a position changing device that can change the relative positional relationships between the stage 31, the workpiece W, and the irradiation optical system 211. Furthermore, when the relative positional relationships between the stage 31, the workpiece W, and the machining head 21 change, the relative positional relationships between the target irradiation areas EA#1 and EA#2 and the target supply area MA and the workpiece W also change. In other words, the target irradiation areas EA#1 and EA#2 and the target supply area MA each move on the surface of the workpiece W (more specifically, the printing surface MS) along at least one of the X-axis direction, Y-axis direction, Z-axis direction, θX direction, θY direction, and θZ direction. In this case, it may be considered that the stage drive system 32 moves the stage 31 so that the target irradiation areas EA#1 and EA#2 and the target supply area MA each move on the printing surface MS.

[0059] The light source 4 emits, for example, at least one of infrared light, visible light, and ultraviolet light as the processing light EL. However, other types of light may be used as the processing light EL. The processing light EL may include a plurality of pulsed lights (i.e., a plurality of pulse beams). The processing light EL may be laser light. In this case, the light source 4 may include a laser light source (e.g., a semiconductor laser such as a laser diode (LD)). Examples of laser light sources include fiber lasers, CO ２ At least one of a laser, a YAG laser, an excimer laser, etc. may be used. However, the processing light EL does not have to be laser light. The light source 4 may include any light source (for example, at least one of an LED (Light Emitting Diode), a discharge lamp, etc.).

[0060] As described above, the processing system SYS includes multiple light sources 4 (specifically, light sources 4#1 and 4#2). In this case, the characteristics of the processing light EL#1 emitted by light source 4#1 and the characteristics of the processing light EL#2 emitted by light source 4#2 may be the same. For example, the wavelength of the processing light EL#1 (typically, the peak wavelength, which is the wavelength at which the intensity is maximum in the wavelength band of the processing light EL#1) and the wavelength of the processing light EL#2 (typically, the peak wavelength) may be the same. For example, the wavelength band of the processing light EL#1 (typically, the range of wavelengths at which the intensity is equal to or greater than a certain value) and the wavelength band of the processing light EL#2 may be the same. For example, the intensity of the processing light EL#1 and the intensity of the processing light EL#2 may be the same. For example, the absorptivity of the workpiece W for the processing light EL#1 (or the object whose surface MS is the surface; the same applies below) may be the same as the absorptivity of the workpiece W for the processing light EL#2. In particular, the absorptivity of the workpiece W for the peak wavelength of processing light EL#1 and the absorptivity of the workpiece W for the peak wavelength of processing light EL#2 may be the same. Alternatively, the characteristics of processing light EL#1 emitted by light source 4#1 and the characteristics of processing light EL#2 emitted by light source 4#2 may be different. For example, the wavelength (typically, peak wavelength) of processing light EL#1 and the wavelength (typically, peak wavelength) of processing light EL#2 may be different. For example, the wavelength band of processing light EL#1 and the wavelength band of processing light EL#2 may be different. For example, the intensity of processing light EL#1 and the intensity of processing light EL#2 may be different. For example, the absorptivity of the workpiece W for processing light EL#1 and the absorptivity of the workpiece W for processing light EL#2 may be different. In particular, the absorptivity of the workpiece W for the peak wavelength of processing light EL#1 and the absorptivity of the workpiece W for the peak wavelength of processing light EL#2 may be different.

[0061] In this embodiment, an example is described in which the processing system SYS includes multiple light sources 4. However, the processing system SYS does not necessarily have to include multiple light sources 4. The processing system SYS does not necessarily have to include a single light source 4. As an example, the processing system may include a light source that emits (supplies) light in a wide wavelength band or multiple wavelengths as the single light source 4. In this case, the processing system SYS may generate processing light EL#1 and processing light EL#2 having different wavelengths by wavelength-dividing the light emitted from this light source.

[0062] The gas supply source 5 is a supply source of purge gas for purging the chamber space 63IN inside the housing 6. The purge gas includes an inert gas. Examples of the inert gas include nitrogen gas and argon gas. The gas supply source 5 is connected to the chamber space 63IN via a supply port 62 formed in a partition member 61 of the housing 6 and a supply pipe 51 connecting the gas supply source 5 and the supply port 62. The gas supply source 5 supplies purge gas to the chamber space 63IN via the supply pipe 51 and the supply port 62. As a result, the chamber space 63IN becomes a space purged with the purge gas. The purge gas supplied to the chamber space 63IN may be discharged from an exhaust port (not shown) formed in the partition member 61. The gas supply source 5 may be a cylinder containing an inert gas. When the inert gas is nitrogen gas, the gas supply source 5 may be a nitrogen gas generator that generates nitrogen gas using atmospheric air as a raw material.

[0063] As described above, when the material nozzle 212 supplies the modeling material M together with a purge gas, the gas supply source 5 may supply the purge gas to the mixer 12 to which the modeling material M is supplied from the material supply source 1. Specifically, the gas supply source 5 may be connected to the mixer 12 via a supply pipe 52 connecting the gas supply source 5 and the mixer 12. As a result, the gas supply source 5 supplies the purge gas to the mixer 12 via the supply pipe 52. In this case, the modeling material M from the material supply source 1 may be supplied (specifically, pressure-fed) through the supply pipe 11 toward the material nozzle 212 by the purge gas supplied from the gas supply source 5 via the supply pipe 52. In other words, the gas supply source 5 may be connected to the material nozzle 212 via the supply pipe 52, the mixer 12, and the supply pipe 11. In this case, the material nozzle 212 supplies the modeling material M together with the purge gas for pressure-fed the modeling material M.

[0064] The control unit 7 controls the operation of the machining system SYS. For example, the control unit 7 may control the machining unit 2 (e.g., at least one of the machining head 21 and the head drive system 22) provided in the machining system SYS to perform additional machining on the workpiece W. For example, the control unit 7 may control the stage unit 3 (e.g., the stage drive system 32) provided in the machining system SYS to perform additional machining on the workpiece W. For example, the control unit 7 may control the material supply source 1 provided in the machining system SYS to perform additional machining on the workpiece W. For example, the control unit 7 may control the light source 4 provided in the machining system SYS to perform additional machining on the workpiece W. For example, the control unit 7 may control the gas supply source 5 provided in the machining system SYS to perform additional machining on the workpiece W.

[0065] The control unit 7 may include, for example, an arithmetic device 71 and a storage device 72. The arithmetic device 71 may include, for example, at least one of a CPU (Central Processing Unit) and a GPU (Graphics Processing Unit). The storage device 72 may include, for example, a memory. The control unit 7 functions as a device that controls the operation of the machining system SYS when the arithmetic device 71 executes a computer program. This computer program is a computer program for causing the arithmetic device 71 to perform (i.e., execute) the operations to be performed by the control unit 7, which will be described later. In other words, this computer program is a computer program for causing the control unit 7 to function so as to cause the machining system SYS to perform the operations to be described later. The computer program executed by the arithmetic device 71 may be recorded in the storage device 72 (i.e., a recording medium) included in the control unit 7, or may be recorded in any storage medium (e.g., a hard disk or a semiconductor memory) built into the control unit 7 or externally attachable to the control unit 7. Alternatively, the computing device 71 may download the computer program to be executed from a device external to the control unit 7 via a network interface. The storage device 72 may also be called a recording device.

[0066] The control unit 7 may control the emission mode of the processing light EL by the irradiation optical system 211. The emission mode may include, for example, at least one of the intensity of the processing light EL and the emission timing of the processing light EL. When the processing light EL includes multiple pulsed lights, the emission mode may include, for example, at least one of the emission duration of the pulsed light, the emission cycle of the pulsed light, and the ratio between the emission duration of the pulsed light and the emission cycle of the pulsed light (so-called duty ratio). Furthermore, the control unit 7 may control the movement mode of the processing head 21 by the head drive system 22. The control unit 7 may control the movement mode of the stage 31 by the stage drive system 32. The movement mode may include, for example, at least one of the movement amount, movement speed, movement direction, and movement timing (movement time). Furthermore, the control unit 7 may control the supply mode of the modeling material M by the material nozzle 212. The supply mode may include, for example, at least one of the supply amount (particularly, the supply amount per unit time) and the supply timing (supply time).

[0067] The control unit 7 does not have to be provided inside the machining system SYS. For example, the control unit 7 may be provided outside the machining system SYS as a server or the like. In this case, the control unit 7 and the machining system SYS may be connected via a wired and / or wireless network (or a data bus and / or communication line). The wired network may be a network using a serial bus interface, such as at least one of IEEE1394, RS-232x, RS-422, RS-423, RS-485, and USB. The wired network may be a network using a parallel bus interface. The wired network may be a network using an interface compliant with Ethernet (registered trademark), such as at least one of 10BASE-T, 100BASE-TX, and 1000BASE-T. The wireless network may be a network using radio waves. An example of a network using radio waves is a network compliant with IEEE 802.1x (for example, at least one of a wireless LAN and Bluetooth (registered trademark)). A network using infrared rays may be used as the wireless network. A network using optical communication may be used as the wireless network. In this case, the control unit 7 and the machining system SYS may be configured to be able to send and receive various information via the network. The control unit 7 may also be able to send information such as commands and control parameters to the machining system SYS via the network. The machining system SYS may include a receiving device that receives information such as commands and control parameters from the control unit 7 via the network. The machining system SYS may also include a transmitting device (i.e., an output device that outputs information to the control unit 7) that transmits information such as commands and control parameters to the control unit 7 via the network.Alternatively, a first control device that performs part of the processing performed by the control unit 7 may be provided inside the processing system SYS, while a second control device that performs another part of the processing performed by the control unit 7 may be provided outside the processing system SYS.

[0068] A computational model that can be constructed by machine learning may be implemented in the control unit 7 by the arithmetic device 71 executing a computer program. An example of a computational model that can be constructed by machine learning is a computational model including a neural network (so-called artificial intelligence (AI)). In this case, learning of the computational model may include learning of parameters of the neural network (e.g., at least one of a weight and a bias). The control unit 7 may use the computational model to control the operation of the machining system SYS. In other words, the operation of controlling the operation of the machining system SYS may include the operation of controlling the operation of the machining system SYS using the computational model. Note that a computational model that has been constructed by offline machine learning using training data may be implemented in the control unit 7. Furthermore, the computational model implemented in the control unit 7 may be updated on the control unit 7 by online machine learning. Alternatively, the control unit 7 may control the operation of the machining system SYS using a calculation model implemented in a device external to the control unit 7 (that is, a device provided outside the machining system SYS) in addition to or instead of the calculation model implemented in the control unit 7.

[0069] The recording medium for recording the computer program executed by the control unit 7 may be at least one of the following: a CD-ROM, CD-R, CD-RW, a flexible disk, an MO, a DVD-ROM, a DVD-RAM, a DVD-R, a DVD+R, a DVD-RW, a DVD+RW, and an optical disk such as Blu-ray (registered trademark), a magnetic medium such as a magnetic tape, a magneto-optical disk, a semiconductor memory such as a USB memory, and any other medium capable of storing a program. The recording medium may also include a device capable of recording a computer program (for example, a general-purpose device or a dedicated device in which a computer program is implemented in an executable state in at least one of the forms of software and firmware). Furthermore, each process or function included in the computer program may be realized by a logical processing block realized in the control unit 7 when the control unit 7 (i.e., the computer) executes the computer program, or may be realized by hardware such as a predetermined gate array (FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit)) included in the control unit 7, or may be realized in a form in which the logical processing block and a partial hardware module that realizes some elements of the hardware are mixed.

[0070] The imaging unit 8 is an imaging device capable of capturing an image of an imaging target under the control of the control unit 7. Therefore, the imaging unit 8 may include a camera capable of capturing an image of the imaging target. The camera may include an imaging element. The imaging element may include a CCD (Charged Coupled Device) sensor. The imaging element may include a CMOS (Complementary Metal Oxide Semiconductor) sensor. In this case, the imaging unit 8 may capture an image of the imaging target by receiving light from the imaging target with the imaging element. In other words, the imaging unit 8 may capture an image of the imaging target by exposing the imaging element to light from the imaging target. Note that "exposure of the imaging element using light from the imaging target" may also be referred to as "exposure by the imaging element (i.e., by the imaging unit 8) (exposure of the imaging target)."

[0071] The imaged object may include at least a portion of the workpiece W. The imaged object may include at least a portion of a structure formed by the processing system SYS. In particular, the imaged object may include at least a portion of an object on which a structure surface MS is set. As described above, the structure surface MS is set on the surface of the workpiece W or the structure layer SL. Therefore, the imaged object may include at least a portion of the workpiece W or at least a portion of the structure layer SL.

[0072] As described above, a molten pool MP is formed on the build surface MS by the processing light EL. In this case, the imaging unit 8 may be capable of imaging the molten pool MP. That is, the imaging unit 8 may be capable of imaging an area including the molten pool MP (i.e., an area on the build surface MS that includes the molten pool MP). In the following description, an example will be described in which the imaging unit 8 images the molten pool MP. That is, in the following description, an example will be described in which the imaging unit 8 images an area including the molten pool MP (i.e., an area on the build surface MS that includes the molten pool MP).

[0073] The imaging unit 8 may be attached to the processing head 21. For example, as shown in FIG. 1 , the imaging unit 8 may be attached to the head housing 213 of the processing head 21. In this case, when the processing head 21 is moved by the head drive system 22, the imaging unit 8 attached to the processing head 21 also moves together with the processing head 21. In this case, the relative positional relationship between the processing head 21 and the imaging unit 8 is fixed. However, the imaging unit 8 does not have to be attached to the processing head 21. The imaging unit 8 may be attached to an object different from the processing head 21.

[0074] The imaging unit 8 captures an image of the object to be imaged, thereby generating an image in which the object to be imaged is captured. In this embodiment, since the imaging unit 8 captures an image of the molten pool MP as described above, the imaging unit 8 generates an image in which the molten pool MP is captured. In the following description, the image generated by the imaging unit 8 (i.e., the image in which the molten pool MP is captured) will be referred to as a "molten pool image IMG."

[0075] The imaging unit 8 may output the generated molten pool image IMG to the control unit 7. The control unit 7 may control the machining system SYS based on the molten pool image IMG. For example, the control unit 7 may control the machining unit 2 (e.g., at least one of the machining head 21 and the head drive system 22) to perform additional machining on the workpiece W based on the molten pool image IMG. For example, the control unit 7 may control the stage unit 3 (e.g., the stage drive system 32) to perform additional machining on the workpiece W based on the molten pool image IMG. For example, the control unit 7 may control the material supply source 1 to perform additional machining on the workpiece W based on the molten pool image IMG. For example, the control unit 7 may control the light source 4 to perform additional machining on the workpiece W based on the molten pool image IMG. For example, the control unit 7 may control the gas supply source 5 to perform additional machining on the workpiece W based on the molten pool image IMG.

[0076] (1-2) Structure of the Irradiation Optical System 211 Next, the structure of the irradiation optical system 211 will be described with reference to Fig. 3. Fig. 3 is a cross-sectional view showing the structure of the irradiation optical system 211.

[0077] As shown in FIG. 3 , the irradiation optical system 211 includes a first optical system 214, a second optical system 215, and a third optical system 216. The first optical system 214 is an optical system into which the processing light EL#1 emitted from the light source 4#1 is incident. The first optical system 214 is an optical system that outputs the processing light EL#1 emitted from the light source 4#1 toward the third optical system 216. The second optical system 215 is an optical system into which the processing light EL#2 emitted from the light source 4#2 is incident. The second optical system 215 is an optical system that outputs the processing light EL#2 emitted from the light source 4#2 toward the third optical system 216. The third optical system 216 is an optical system into which the processing light EL#1 emitted from the first optical system 214 and the processing light EL#2 emitted from the second optical system 215 are incident. The third optical system 216 is an optical system that emits the processing light EL#1 emitted from the first optical system 214 and the processing light EL#2 emitted from the second optical system 215 toward the printing surface MS. Below, the first optical system 214, the second optical system 215, and the third optical system 216 will be described in order.

[0078] The first optical system 214 includes a collimator lens 2141, a parallel plate 2142, a power meter 2143, and a galvanometer scanner 2144. The galvanometer scanner 2144 includes a focus control optical system 2145 and a galvanometer mirror 2146. However, the first optical system 214 does not necessarily have to include at least one of the collimator lens 2141, the parallel plate 2142, the power meter 2143, and the galvanometer scanner 2144. The galvanometer scanner 2144 does not necessarily have to include at least one of the focus control optical system 2145 and the galvanometer mirror 2146.

[0079] The processing light EL#1 emitted from the light source 4#1 is incident on the collimator lens 2141. The collimator lens 2141 converts the processing light EL#1 incident on the collimator lens 2141 into parallel light. Note that if the processing light EL#1 emitted from the light source 4#1 is parallel light (i.e., if the processing light EL#1, which is parallel light, enters the first optical system 214), the first optical system 214 does not need to be equipped with the collimator lens 2141. The processing light EL#1 converted into parallel light by the collimator lens 2141 is incident on the parallel plate 2142. A portion of the processing light EL#1 incident on the parallel plate 2142 passes through the parallel plate 2142. The other portion of the processing light EL#1 incident on the parallel plate 2142 is reflected by the parallel plate 2142.

[0080] The processing light EL#1 that has passed through the parallel plate 2142 is incident on the galvanometer scanner 2144. Specifically, the processing light EL#1 that has passed through the parallel plate 2142 is incident on the focus control optical system 2145 of the galvanometer scanner 2144.

[0081] The focus control optical system 2145 is an optical element that can change the focusing position CP of the processing light EL#1 (hereinafter referred to as the "focus position CP#1"). Specifically, the focus control optical system 2145 can change the focusing position CP#1 of the processing light EL#1 along the irradiation direction of the processing light EL#1 that is irradiated onto the printing surface MS. In the example shown in FIG. 3, the irradiation direction of the processing light EL#1 that is irradiated onto the printing surface MS is a direction in which the Z-axis direction is the main component. In this case, the focus control optical system 2145 can change the focusing position CP#1 of the processing light EL#1 along the Z-axis direction. Furthermore, because the irradiation optical system 211 irradiates the printing surface MS with the processing light EL from above the workpiece W, the irradiation direction of the processing light EL#1 is a direction that intersects with the printing surface MS (e.g., the surface of the workpiece W or the structure layer SL). For this reason, the focus control optical system 2145 may be considered to be able to change the focusing position CP#1 of the processing light EL#1 along a direction intersecting the printing surface MS (e.g., the surface of the workpiece W or the structure layer SL). The focus optical system 2145 may be considered to be able to change the focusing position CP#1 of the processing light EL#1 along the direction of the optical axis AX of the irradiation optical system 211 (typically, the third optical system 216).

[0082] The irradiation direction of the processing light EL#1 may refer to the irradiation direction of the processing light EL#1 emitted from the third optical system 216. In this case, the irradiation direction of the processing light EL#1 may be the same as the direction along the optical axis of the third optical system 216. The irradiation direction of the processing light EL#1 may be the same as the direction along the optical axis of the final optical element that is arranged closest to the printing surface MS among the optical elements constituting the third optical system 216. The final optical element may be the fθ lens 2162 described below. Furthermore, if the fθ lens 2162 described below is composed of multiple optical elements, the final optical element may be the optical element that is arranged closest to the printing surface MS among the multiple optical elements constituting the fθ lens 2162.

[0083] The focus control optical system 2145 may include, for example, a plurality of lenses arranged along the irradiation direction of the processing light EL#1. In this case, the focus control optical system 2145 may change the focusing position CP#1 of the processing light EL#1 by moving at least one of the plurality of lenses along its optical axis direction.

[0084] When the focus control optical system 2145 changes the condensing position CP#1 of the processing light EL#1, the positional relationship between the condensing position CP#1 of the processing light EL#1 and the printing surface MS changes. In particular, the positional relationship between the condensing position CP#1 of the processing light EL#1 and the printing surface MS in the irradiation direction of the processing light EL#1 changes. For this reason, it can be considered that the focus control optical system 2145 changes the positional relationship between the condensing position CP#1 of the processing light EL#1 and the printing surface MS by changing the condensing position CP#1 of the processing light EL#1.

[0085] As described above, the galvanometer scanner 2144 does not necessarily have to include the focus control optical system 2145. Even in this case, if the positional relationship between the irradiation optical system 211 and the printing surface MS in the irradiation direction of the processing light EL#1 changes, the positional relationship between the condensing position CP#1 of the processing light EL#1 and the printing surface MS in the irradiation direction of the processing light EL#1 changes. Therefore, even if the galvanometer scanner 2144 does not include the focus control optical system 2145, the processing system SYS can change the positional relationship between the condensing position CP#1 of the processing light EL#1 and the printing surface MS in the irradiation direction of the processing light EL#1. For example, the processing system SYS may change the positional relationship between the condensing position CP#1 of the processing light EL#1 and the printing surface MS in the irradiation direction of the processing light EL#1 by using the head drive system 22 to move the processing head 21 along the irradiation direction of the processing light EL#1. For example, the processing system SYS may use the stage drive system 32 to move the stage 31 along the irradiation direction of the processing light EL#1, thereby changing the positional relationship between the focusing position CP#1 of the processing light EL#1 in the irradiation direction of the processing light EL#1 and the manufacturing surface MS.

[0086] The processing light EL#1 emitted from the focus control optical system 2145 is incident on the galvanometer mirror 2146. The galvanometer mirror 2146 deflects the processing light EL#1, thereby changing the emission direction of the processing light EL#1 emitted from the galvanometer mirror 2146. For this reason, the galvanometer mirror 2146 may be referred to as a deflection optical system. When the emission direction of the processing light EL#1 emitted from the galvanometer mirror 2146 is changed, the position from which the processing light EL#1 is emitted from the processing head 21 is changed. When the position from which the processing light EL#1 is emitted from the processing head 21 is changed, the target irradiation area EA#1 onto which the processing light EL#1 is irradiated on the printing surface MS moves. In other words, the irradiation position onto which the processing light EL#1 is irradiated on the printing surface MS moves. For this reason, the galvanometer mirror 2146 may be considered to function as an irradiation position moving device that can move the irradiation position of the processing light EL#1 on the printing surface MS.

[0087] In particular, when the emission direction of processing light EL#1 emitted from the galvanometer mirror 2146 is changed, the irradiation position of processing light EL#1 with respect to the processing head 21 including the galvanometer mirror 2146 is changed. For this reason, the galvanometer mirror 2146 may be considered to function as a position changing device that can change the irradiation position of processing light EL#1 with respect to the processing head 21.

[0088] The galvanometer mirror 2146 includes, for example, an X-scan mirror 2146MX, an X-scan motor 2146AX, a Y-scan mirror 2146MY, and a Y-scan motor 2146AY. The processing light EL#1 emitted from the focus control optical system 2145 is incident on the X-scan mirror 2146MX. The X-scan mirror 2146MX reflects the processing light EL#1 incident on the X-scan mirror 2146MX toward the Y-scan mirror 2146MY. The Y-scan mirror 2146MY reflects the processing light EL#1 incident on the Y-scan mirror 2146MY toward the third optical system 216. Note that each of the X-scan mirror 2146MX and the Y-scan mirror 2146MY may be referred to as a galvanometer mirror.

[0089] The X-scan motor 2146AX swings or rotates the X-scan mirror 2146MX around a rotation axis along the Y-axis. As a result, the angle of the X-scan mirror 2146MX with respect to the optical path of processing light EL#1 incident on the X-scan mirror 2146MX is changed. In this case, the swing or rotation of the X-scan mirror 2146MX causes processing light EL#1 to scan the printing surface MS along the X-axis direction. In other words, the target irradiation area EA#1 (i.e., the irradiation position of processing light EL#1) moves along the X-axis direction on the printing surface MS.

[0090] The Y-scan motor 2146AY swings or rotates the Y-scan mirror 2146MY around a rotation axis along the X-axis. As a result, the angle of the Y-scan mirror 2146MY with respect to the optical path of the processing light EL#1 incident on the Y-scan mirror 2146MY is changed. In this case, the swing or rotation of the Y-scan mirror 2146MY causes the processing light EL#1 to scan the printing surface MS along the Y-axis direction. In other words, the target irradiation area EA#1 (i.e., the irradiation position of the processing light EL#1) moves along the Y-axis direction on the printing surface MS.

[0091] In this embodiment, the virtual area on the printing surface MS through which the galvanometer mirror 2146 moves the target irradiation area EA#1 is referred to as the machining unit area BSA (particularly, the machining unit area BSA#1). In this case, the target irradiation area EA#1 may be considered to move on a surface of the printing surface MS that overlaps with the machining unit area BSA#1. Specifically, the virtual area on the printing surface MS through which the galvanometer mirror 2146 moves the target irradiation area EA#1 while the positional relationship between the irradiation optical system 211 and the printing surface MS is fixed (i.e., without changing) is referred to as the machining unit area BSA (particularly, the machining unit area BSA#1). The machining unit area BSA#1 indicates the virtual area (in other words, the range) through which the machining head 21 actually performs additional machining using the machining light EL#1 while the positional relationship between the irradiation optical system 211 and the printing surface MS is fixed. The processing unit area BSA#1 indicates a virtual area (in other words, a range) that the processing head 21 actually scans with the processing light EL#1 when the positional relationship between the irradiation optical system 211 and the printing surface MS is fixed. The processing unit area BSA#1 indicates a region (in other words, a range) through which the target irradiation area EA#1 actually moves when the positional relationship between the irradiation optical system 211 and the printing surface MS is fixed. Therefore, the processing unit area BSA#1 may be considered to be a virtual region determined based on the processing head 21 (particularly, the irradiation optical system 211). In other words, the processing unit area BSA#1 may be considered to be a virtual region located at a position on the printing surface MS that is determined based on the processing head 21 (particularly, the irradiation optical system 211). Note that the maximum region over which the galvanometer mirror 2146 can move the target irradiation area EA#1 on the printing surface MS when the positional relationship between the irradiation optical system 211 and the printing surface MS is fixed may also be referred to as the processing unit area BSA#1.

[0092] In this case, the machining system SYS can use the galvanometer mirror 2146 to move the target irradiation area EA#1 within the machining unit area BSA#1. Therefore, the operation of deflecting the machining light EL#1 using the galvanometer mirror 2146 may be considered equivalent to the operation of moving the target irradiation area EA#1 within the machining unit area BSA#1. Furthermore, as described above, the molten pool MP#1 is formed by irradiating the target irradiation area EA#1 with the machining light EL#1. In this case, the machining system SYS may be considered to move the molten pool MP#1 within the machining unit area BSA#1 using the galvanometer mirror 2146. Therefore, the operation of deflecting the machining light EL#1 using the galvanometer mirror 2146 may be considered equivalent to the operation of moving the molten pool MP#1 within the machining unit area BSA#1. In other words, the operation of moving the target irradiation area EA#1 within the machining unit area BSA#1 may be considered equivalent to the operation of moving the molten pool MP#1 within the machining unit area BSA#1.

[0093] As described above, even if at least one of the machining head 21 and the stage 31 moves, the target irradiation area EA#1 moves on the printing surface MS. However, when at least one of the machining head 21 and the stage 31 moves, the relative positional relationship between the galvanometer mirror 2146 and the printing surface MS changes. As a result, the machining unit area BSA#1 determined based on the machining head 21 (i.e., the machining unit area BSA#1 to which the galvanometer mirror 2146 moves the target irradiation area EA#1 on the printing surface MS) moves on the printing surface MS. For this reason, in this embodiment, the operation of moving at least one of the machining head 21 and the stage 31 may be considered equivalent to the operation of moving the machining unit area BSA#1 relative to the printing surface MS.

[0094] As an example of an operation for moving the target irradiation area EA#1 within the processing unit area BSA#1, as shown in FIG. 4A, the galvanometer mirror 2146 may deflect the processing light EL#1 so that the target irradiation area EA#1 moves within the processing unit area BSA#1 along a single scanning direction along the printing surface MS, assuming that the processing unit area BSA#1 is stationary (i.e., not moving) on ​​the printing surface MS. In other words, the galvanometer mirror 2146 may deflect the processing light EL#1 so that the target irradiation area EA#1 moves along a single scanning direction within a coordinate system defined based on the processing unit area BSA#1. In particular, the galvanometer mirror 2146 may deflect the processing light EL#1 so that the target irradiation area EA#1 periodically moves back and forth within the processing unit area BSA#1 along the single scanning direction. In other words, the galvanometer mirror 2146 may deflect the processing light EL#1 so that the target irradiation area EA#1 periodically moves back and forth on an axis along a single scanning direction within the processing unit area BSA#1. In this case, the shape of the processing unit area BSA#1 along which the target irradiation area EA#1 moves may be a rectangle whose longitudinal direction is the movement direction of the target irradiation area EA#1.

[0095] As another example of the operation of moving the molten pool MP#1 within the machining unit area BSA#1, as shown in Figures 5(a) and 5(b), the galvanometer mirror 2146 may deflect the machining light EL#1 so that the target irradiation area EA#1 moves along multiple scanning directions along the machining surface MS within the machining unit area BSA#1, assuming that the machining unit area BSA#1 is stationary (i.e., not moving) on ​​the machining surface MS. In other words, the galvanometer mirror 2146 may deflect the machining light EL#1 so that the target irradiation area EA#1 moves along multiple scanning directions within a coordinate system defined based on the machining unit area BSA#1. In particular, the galvanometer mirror 2146 may deflect the machining light EL#1 so that the target irradiation area EA#1 periodically moves back and forth along each of the multiple scanning directions within the machining unit area BSA#1. That is, the galvanometer mirror 2146 may deflect the processing light EL#1 so that the target irradiation area EA#1 periodically moves back and forth on axes along each of the multiple scanning directions within the processing unit area BSA#1. Figure 5(a) shows an example in which the target irradiation area EA#1 moves back and forth along each of the X-axis and Y-axis directions within the processing unit area BSA#1 so that the movement trajectory of the target irradiation area EA#1 within the processing unit area BSA#1 is circular. In this case, the shape of the processing unit area BSA#1 through which the target irradiation area EA#1 moves may be circular. Figure 5(b) shows an example in which the target irradiation area EA#1 moves back and forth along each of the X-axis and Y-axis directions within the processing unit area BSA#1 so that the movement trajectory of the target irradiation area EA#1 within the processing unit area BSA#1 is mesh-shaped. In this case, the shape of the processing unit area BSA#1 through which the target irradiation area EA#1 moves may be rectangular.

[0096] 4A, 5A, and 5B, the operation of periodically moving the target irradiation area EA#1 on the printing surface MS may be referred to as a wobbling operation. In other words, the operation of periodically moving (or deflecting) the processing light EL#1 so that the target irradiation area EA#1 moves periodically on the printing surface MS may be referred to as a wobbling operation.

[0097] The control unit 7 may move at least one of the machining head 21 and the stage 31 so that the machining unit area BSA#1 moves on the manufacturing surface MS during a period in which the target irradiation area EA#1 is moved within the machining unit area BSA#1 using the galvanometer mirror 2146. In other words, the control unit 7 may control at least one of the head drive system 22 and the stage drive system 32 so that the machining unit area BSA#1 moves on the manufacturing surface MS during a period in which the target irradiation area EA#1 is moved within the machining unit area BSA#1 using the galvanometer mirror 2146.

[0098] For example, in the example shown in FIG. 4A, the control unit 7 may control at least one of the head drive system 22 and the stage drive system 32 so that the processing unit area BSA#1 moves along a target movement trajectory MT0 that intersects (or, in some cases, is perpendicular to) the movement direction (i.e., the scanning direction) of the target irradiation area EA#1 within the processing unit area BSA#1. Conversely, the control unit 7 may control the galvanometer mirror 2146 so that the target irradiation area EA#1 periodically moves along a scanning direction that intersects (or, in some cases, is perpendicular to) the target movement trajectory MT0 of the processing unit area BSA#1 on the printing surface MS. As a result, on the printing surface MS, the target irradiation area EA#1 may move along the movement trajectory MT#1 shown in FIG. 4B. Specifically, the target irradiation area EA#1 may move along the target movement trajectory MT0 of the processing unit area BSA#1 while moving along a scanning direction that intersects with the target movement trajectory MT0. That is, the target irradiation area EA#1 may move along a wave-shaped (for example, sinusoidal) movement locus MT#1 that oscillates around the target movement locus MT0.

[0099] 5(a) or 5(b), the control unit 7 may control at least one of the head drive system 22 and the stage drive system 32 so that the processing unit area BSA#1 moves along a target movement trajectory MT0 extending along at least one of a direction along the movement direction (i.e., the scanning direction) of the target irradiation area EA#1 within the processing unit area BSA#1 and a direction intersecting (or, in some cases, perpendicular to) the movement direction of the target irradiation area EA#1 within the processing unit area BSA#1. Conversely, the control unit 7 may control the galvanometer mirror 2146 so that the target irradiation area EA#1 periodically moves along each of a scanning direction along the target movement trajectory MT0 of the processing unit area BSA#1 on the printing surface MS and a scanning direction intersecting (or, in some cases, perpendicular to) the target movement trajectory MT0. Note that Figure 5(c) shows the movement trajectory MT#1 of the target irradiation area EA#1 on the printing surface MS when the processing unit area BSA#1 shown in Figure 5(a) moves along the target movement trajectory MT0 on the printing surface MS.

[0100] When the processing light EL#1 is irradiated onto the printing surface MS in units of processing unit areas BSA#1, a molten pool MP#1 is formed in at least a portion of the processing unit area BSA#1. As a result, a molded object is formed within the processing unit area BSA#1. As described above, the processing unit area BSA#1 is an area having a width in a direction intersecting the movement direction of the processing unit area BSA#1 on the printing surface MS (specifically, the direction in which the target movement trajectory MT0 extends). In this case, a molded object having a width in a direction intersecting the target movement trajectory MT0 of the processing unit area BSA#1 is formed on the printing surface MS. For example, in the example shown in FIGS. 4( a) and 4(b), a molded object having a width along the X-axis direction and extending along the Y-axis direction is formed. For example, in the example shown in FIGS. 5(a) and 5(c), a molded object having a width along the X-axis direction and extending along the Y-axis direction is formed.

[0101] When the processing light EL#1 is irradiated onto the printing surface MS in units of processing unit areas BSA#1, the processing unit areas BSA#1 are scanned with the processing light EL#1 by the galvanometer mirror 2146. Therefore, compared to when the processing light EL#1 is irradiated onto the printing surface MS without using the galvanometer mirror 2146, the amount of energy transmitted from the processing light EL#1 to the processing unit areas BSA#1 is less likely to vary within the processing unit areas BSA#1. In other words, the distribution of the amount of energy transmitted from the processing light EL#1 to the processing unit areas BSA#1 can be made uniform. As a result, the processing system SYS can form a shaped object on the printing surface MS with relatively high printing accuracy.

[0102] However, the machining system SYS does not have to irradiate the manufacturing surface MS with the processing light EL#1 in units of processing unit areas BSA#1. The machining system SYS may irradiate the manufacturing surface MS with the processing light EL#1 without using the galvanometer mirror 2146. In this case, the target irradiation area EA#1 may move on the manufacturing surface MS in conjunction with the movement of at least one of the machining head 21 and the stage 31.

[0103] Referring again to FIG. 3 , the processing light EL#1 reflected by the parallel plate 2142 is incident on the power meter 2143. The power meter 2143 can detect the intensity of the processing light EL#1 incident on the power meter 2143. For example, the power meter 2143 may include a light-receiving element that detects the processing light EL#1 as light. Alternatively, the higher the intensity of the processing light EL#1, the greater the amount of energy generated by the processing light EL#1. As a result, the amount of heat generated by the processing light EL#1 increases. Therefore, the power meter 2143 may detect the intensity of the processing light EL#1 by detecting the processing light EL#1 as heat. In this case, the power meter 2143 may include a heat-detecting element that detects the heat of the processing light EL#1.

[0104] As described above, the processing light EL#1 reflected by the parallel plate 2142 is incident on the power meter 2143. Therefore, the power meter 2143 detects the intensity of the processing light EL#1 reflected by the parallel plate 2142. Because the parallel plate 2142 is disposed on the optical path of the processing light EL#1 between the light source 4#1 and the galvanometer mirror 2146, the power meter 2143 may be considered to detect the intensity of the processing light EL#1 traveling along the optical path between the light source 4#1 and the galvanometer mirror 2146. In this case, the power meter 2143 can stably detect the intensity of the processing light EL#1 without being affected by the deflection of the processing light EL#1 by the galvanometer mirror 2146. However, the location of the power meter 2143 is not limited to the example shown in FIG. 3 . For example, the power meter 2143 may detect the intensity of the processing light EL#1 traveling along the optical path between the galvanometer mirror 2146 and the printing surface MS. The power meter 2143 may detect the intensity of the processing light EL#1 traveling along the optical path within the galvanometer mirror 2146.

[0105] The detection result of the power meter 2143 is output to the control unit 7. The control unit 7 may control (in other words, change) the intensity of the processing light EL#1 based on the detection result of the power meter 2143 (i.e., the detection result of the intensity of the processing light EL#1). For example, the control unit 7 may control the intensity of the processing light EL#1 so that the intensity of the processing light EL#1 on the printing surface MS becomes a desired intensity. To control the intensity of the processing light EL#1, for example, the control unit 7 may control the light source 4#1 to change the intensity of the processing light EL#1 emitted from the light source 4#1 based on the detection result of the power meter 2143. As a result, the processing system SYS can appropriately print a model on the printing surface MS by irradiating the printing surface MS with processing light EL#1 having an appropriate intensity.

[0106] As described above, the processing light EL#1 has an intensity capable of melting the shaping material M. Therefore, the processing light EL#1 incident on the power meter 2143 may have an intensity capable of melting the shaping material M. However, if the processing light EL#1 having an intensity capable of melting the shaping material M is incident on the power meter 2143, the power meter 2143 may be damaged by the processing light EL#1. Therefore, the processing light EL#1 may be incident on the power meter 2143 with an intensity not high enough to damage the power meter 2143. In other words, the first optical system 214 may weaken the intensity of the processing light EL#1 incident on the power meter 2143 so that the processing light EL#1 having an intensity not high enough to damage the power meter 2143 is incident on the power meter 2143.

[0107] For example, in order to weaken the intensity of the processing light EL#1 incident on the power meter 2143, the reflectivity of the parallel plate 2142 for the processing light EL#1 may be set to an appropriate value. Specifically, the lower the reflectivity of the parallel plate 2142 for the processing light EL#1, the lower the intensity of the processing light EL#1 incident on the power meter 2143. Therefore, the reflectivity of the parallel plate 2142 may be set to a value low enough to realize a state in which the processing light EL#1, having an intensity not high enough to damage the power meter 2143, is incident on the power meter 2143. For example, the reflectivity of the parallel plate 2142 may be less than 10%. For example, the reflectivity of the parallel plate 2142 may be less than a few percent. Plain glass may be used as the parallel plate 2142 with such low reflectivity.

[0108] For example, in order to weaken the intensity of the processing light EL#1 incident on the power meter 2143, the first optical system 214 may cause the processing light EL#1 to be incident on the power meter 2143 via multiple parallel plates 2142. Specifically, the processing light EL#1 may be reflected multiple times by each of the multiple parallel plates 2142 and incident on the power meter 2143. In this case, the intensity of the processing light EL#1 reflected multiple times by each of the multiple parallel plates 2142 is weaker than the intensity of the processing light EL#1 reflected once by a single parallel plate 2142. Therefore, there is a high possibility that the processing light EL#1 having an intensity not high enough to damage the power meter 2143 will be incident on the power meter 2143.

[0109] A desired coating treatment may be applied to the surface of the parallel plate 2142 (particularly, at least one of the incident surface onto which the processing light EL#1 is incident and the reflecting surface onto which the processing light EL#1 is reflected). For example, the surface of the parallel plate 2142 may be subjected to anti-reflection coating (AR).

[0110] The second optical system 215 includes a collimator lens 2151, a parallel plate 2152, a power meter 2153, and a galvanometer scanner 2154. The galvanometer scanner 2154 includes a focus control optical system 2155 and a galvanometer mirror 2156. However, the second optical system 215 does not necessarily have to include at least one of the collimator lens 2151, the parallel plate 2152, the power meter 2153, and the galvanometer scanner 2154. The galvanometer scanner 2154 does not necessarily have to include at least one of the focus control optical system 2155 and the galvanometer mirror 2156.

[0111] The processing light EL#2 emitted from the light source 4#2 is incident on the collimator lens 2151. The collimator lens 2151 converts the processing light EL#2 incident on the collimator lens 2151 into parallel light. Note that if the processing light EL#2 emitted from the light source 4#2 is parallel light (i.e., if the processing light EL#2, which is parallel light, enters the second optical system 215), the second optical system 215 does not need to include the collimator lens 2151. The processing light EL#2 converted into parallel light by the collimator lens 2151 is incident on the parallel plate 2152. A portion of the processing light EL#2 incident on the parallel plate 2152 passes through the parallel plate 2152. The other portion of the processing light EL#2 incident on the parallel plate 2152 is reflected by the parallel plate 2152.

[0112] Processing light EL#2 that has passed through the parallel plate 2152 is incident on a galvanometer scanner 2154. Specifically, processing light EL#2 that has passed through the parallel plate 2152 is incident on a focus control optical system 2155 of the galvanometer scanner 2154.

[0113] The focus control optical system 2155 is an optical element that can change the focusing position CP of the processing light EL#2 (hereinafter referred to as the "focus position CP#2"). Specifically, the focus control optical system 2155 can change the focusing position CP#2 of the processing light EL#2 along the irradiation direction of the processing light EL#2 that is irradiated onto the printing surface MS. In the example shown in FIG. 3, the irradiation direction of the processing light EL#2 that is irradiated onto the printing surface MS is a direction in which the Z-axis direction is the main component. In this case, the focus control optical system 2155 can change the focusing position CP#2 of the processing light EL#2 along the Z-axis direction. Furthermore, because the irradiation optical system 211 irradiates the printing surface MS with the processing light EL from above the workpiece W, the irradiation direction of the processing light EL#2 is a direction that intersects with the printing surface MS (e.g., the surface of the workpiece W or the structure layer SL). For this reason, the focus control optical system 2155 may be considered to be able to change the focusing position CP#2 of the processing light EL#2 along a direction intersecting the printing surface MS (e.g., the surface of the workpiece W or the structure layer SL). The focus optical system 2155 may be considered to be able to change the focusing position CP#2 of the processing light EL#2 along the direction of the optical axis AX of the irradiation optical system 211 (typically, the third optical system 216).

[0114] The irradiation direction of the processing light EL#2 may refer to the irradiation direction of the processing light EL#2 emitted from the third optical system 216. In this case, the irradiation direction of the processing light EL#2 may be the same as the direction along the optical axis of the third optical system 216. The irradiation direction of the processing light EL#2 may be the same as the direction along the optical axis of the final optical element that is arranged closest to the printing surface MS among the optical elements constituting the third optical system 216. The final optical element may be the fθ lens 2162 described below. Furthermore, if the fθ lens 2162 described below is composed of multiple optical elements, the final optical element may be the optical element that is arranged closest to the printing surface MS among the multiple optical elements constituting the fθ lens 2162.

[0115] The focus control optical system 2155 may include, for example, a plurality of lenses arranged along the irradiation direction of the processing light EL#2. In this case, the focus control optical system 2155 may change the focusing position CP of the processing light EL#2 by moving at least one of the plurality of lenses along its optical axis direction.

[0116] When the focus control optical system 2155 changes the condensing position CP#2 of the processing light EL#2, the positional relationship between the condensing position CP#2 of the processing light EL#2 and the printing surface MS changes. In particular, the positional relationship between the condensing position CP#2 of the processing light EL#2 and the printing surface MS in the irradiation direction of the processing light EL#2 changes. For this reason, it can be considered that the focus control optical system 2155 changes the positional relationship between the condensing position CP#2 of the processing light EL#2 and the printing surface MS by changing the condensing position CP#2 of the processing light EL#2.

[0117] As described above, the galvanometer scanner 2154 does not necessarily have to include the focus control optical system 2155. Even in this case, if the positional relationship between the irradiation optical system 211 and the printing surface MS in the irradiation direction of the processing light EL#2 changes, the positional relationship between the condensing position CP#2 of the processing light EL#2 and the printing surface MS in the irradiation direction of the processing light EL#2 changes. Therefore, even if the galvanometer scanner 2154 does not include the focus control optical system 2155, the processing system SYS can change the positional relationship between the condensing position CP#2 of the processing light EL#2 and the printing surface MS in the irradiation direction of the processing light EL#2. For example, the processing system SYS may change the positional relationship between the condensing position CP#2 of the processing light EL#2 and the printing surface MS in the irradiation direction of the processing light EL#2 by using the head drive system 22 to move the processing head 21 along the irradiation direction of the processing light EL#2. For example, the processing system SYS may use the stage drive system 32 to move the stage 31 along the irradiation direction of the processing light EL#2, thereby changing the positional relationship between the focusing position CP#2 of the processing light EL#2 in the irradiation direction of the processing light EL#2 and the manufacturing surface MS.

[0118] The processing light EL#2 emitted from the focus control optical system 2155 is incident on the galvanometer mirror 2156. The galvanometer mirror 2156 deflects the processing light EL#2, thereby changing the emission direction of the processing light EL#2 emitted from the galvanometer mirror 2156. For this reason, the galvanometer mirror 2156 may be referred to as a deflection optical system. When the emission direction of the processing light EL#2 emitted from the galvanometer mirror 2156 is changed, the position from which the processing light EL#2 is emitted from the processing head 21 is changed. When the position from which the processing light EL#2 is emitted from the processing head 21 is changed, the target irradiation area EA#2 onto which the processing light EL#2 is irradiated on the printing surface MS moves. In other words, the irradiation position onto which the processing light EL#2 is irradiated on the printing surface MS moves. For this reason, the galvanometer mirror 2156 may be considered to function as an irradiation position moving device that can move the irradiation position of the processing light EL#2 on the printing surface MS.

[0119] In particular, when the emission direction of the processing light EL#2 emitted from the galvanometer mirror 2156 is changed, the irradiation position of the processing light EL#2 with respect to the processing head 21 including the galvanometer mirror 2156 is changed. Therefore, the galvanometer mirror 2156 may be considered to function as a position changing device that can change the irradiation position of the processing light EL#2 with respect to the processing head 21.

[0120] The galvanometer mirror 2156 includes, for example, an X-scan mirror 2156MX, an X-scan motor 2156AX, a Y-scan mirror 2156MY, and a Y-scan motor 2156AY. Processing light EL#2 emitted from the focus control optical system 2155 is incident on the X-scan mirror 2156MX. The X-scan mirror 2156MX reflects the processing light EL#2 incident on the X-scan mirror 2156MX toward the Y-scan mirror 2156MY. The Y-scan mirror 2156MY reflects the processing light EL#2 incident on the Y-scan mirror 2156MY toward the third optical system 216. Note that each of the X-scan mirror 2156MX and the Y-scan mirror 2156MY may be referred to as a galvanometer mirror.

[0121] The X-scan motor 2156AX swings or rotates the X-scan mirror 2156MX around a rotation axis along the Y-axis. As a result, the angle of the X-scan mirror 2156MX with respect to the optical path of processing light EL#2 incident on the X-scan mirror 2156MX is changed. In this case, the swing or rotation of the X-scan mirror 2156MX causes processing light EL#2 to scan the printing surface MS along the X-axis direction. In other words, the target irradiation area EA#2 (i.e., the irradiation position of processing light EL#2) moves along the X-axis direction on the printing surface MS.

[0122] The Y-scan motor 2156AY swings or rotates the Y-scan mirror 2156MY around a rotation axis along the X-axis. As a result, the angle of the Y-scan mirror 2156MY with respect to the optical path of the processing light EL#2 incident on the Y-scan mirror 2156MY is changed. In this case, the swing or rotation of the Y-scan mirror 2156MY causes the processing light EL#2 to scan the printing surface MS along the Y-axis direction. In other words, the target irradiation area EA#2 (i.e., the irradiation position of the processing light EL#2) moves along the Y-axis direction on the printing surface MS.

[0123] In this embodiment, the virtual area on the printing surface MS through which the galvanometer mirror 2156 moves the target irradiation area EA#2 is referred to as the machining unit area BSA (particularly, the machining unit area BSA#2). In this case, the target irradiation area EA#2 may be considered to move on a surface (first surface) of the printing surface MS that overlaps with the machining unit area BSA#2. Specifically, the virtual area on the printing surface MS through which the galvanometer mirror 2156 moves the target irradiation area EA#2 while the positional relationship between the irradiation optical system 211 and the printing surface MS is fixed (i.e., without change) is referred to as the machining unit area BSA (particularly, the machining unit area BSA#2). The machining unit area BSA#2 indicates a virtual area (in other words, a range) in which the machining head 21 actually performs additional machining using the machining light EL#2 while the positional relationship between the irradiation optical system 211 and the printing surface MS is fixed. The processing unit area BSA#2 indicates a virtual area (in other words, a range) that the processing head 21 actually scans with the processing light EL#2 when the positional relationship between the irradiation optical system 211 and the printing surface MS is fixed. The processing unit area BSA#2 indicates a region (in other words, a range) through which the target irradiation area EA#2 actually moves when the positional relationship between the irradiation optical system 211 and the printing surface MS is fixed. Therefore, the processing unit area BSA#2 may be considered to be a virtual area determined based on the processing head 21 (particularly, the irradiation optical system 211). In other words, the processing unit area BSA#2 may be considered to be a virtual area located at a position on the printing surface MS that is determined based on the processing head 21 (particularly, the irradiation optical system 211). Note that the maximum region over which the galvanometer mirror 2146 can move the target irradiation area EA#2 on the printing surface MS when the positional relationship between the irradiation optical system 211 and the printing surface MS is fixed may also be referred to as the processing unit area BSA#2.

[0124] In this case, the machining system SYS can use the galvanometer mirror 2156 to move the target irradiation area EA#2 within the machining unit area BSA#2. Therefore, the operation of deflecting the machining light EL#2 using the galvanometer mirror 2156 may be considered equivalent to the operation of moving the target irradiation area EA#2 within the machining unit area BSA#2. Furthermore, as described above, the molten pool MP#2 is formed by irradiating the target irradiation area EA#2 with the machining light EL#2. In this case, the machining system SYS may be considered to use the galvanometer mirror 2156 to move the molten pool MP#2 within the machining unit area BSA#2. Therefore, the operation of deflecting the machining light EL#2 using the galvanometer mirror 2156 may be considered equivalent to the operation of moving the molten pool MP#2 within the machining unit area BSA#2. In other words, the operation of moving the target irradiation area EA#2 within the machining unit area BSA#2 may be considered equivalent to the operation of moving the molten pool MP#2 within the machining unit area BSA#2.

[0125] As described above, when at least one of the machining head 21 and the stage 31 moves, the target irradiation area EA#2 moves on the printing surface MS. However, when at least one of the machining head 21 and the stage 31 moves, the relative positional relationship between the galvanometer mirror 2146 and the printing surface MS changes. As a result, the machining unit area BSA#2 determined based on the machining head 21 (i.e., the machining unit area BSA#2 to which the galvanometer mirror 2156 moves the target irradiation area EA#2 on the printing surface MS) moves on the printing surface MS. For this reason, in this embodiment, the operation of moving at least one of the machining head 21 and the stage 31 may be considered equivalent to the operation of moving the machining unit area BSA#2 relative to the printing surface MS.

[0126] The characteristics of the processing unit area BSA#2 (e.g., shape, movement pattern, etc.) may be the same as the characteristics of the processing unit area BSA#1 described above. The movement pattern of the target irradiation area EA#2 within the processing unit area BSA#2 (e.g., movement trajectory, etc.) may be the same as the movement pattern of the target irradiation area EA#1 within the processing unit area BSA#1 described above. For this reason, detailed description of the characteristics of the processing unit area BSA#2 and the movement pattern of the target irradiation area EA#2 within the processing unit area BSA#2 (e.g., movement trajectory, etc.) will be omitted, but an example will be briefly described below. As shown in FIG. 4( a), under the assumption that the processing unit area BSA#2 is stationary (i.e., not moving) on ​​the printing surface MS, the galvanometer mirror 2156 may deflect the processing light EL#2 within the processing unit area BSA#2 so that the target irradiation area EA#2 moves along a single scanning direction along the printing surface MS. 4(a) moves along the target movement trajectory MT0 on the printing surface MS, so that the target irradiation area EA#2 may move along the movement trajectory MT#2 (e.g., a wave-shaped movement trajectory MT#2 oscillating around the target movement trajectory MT0) shown in FIG. 4(b) on the printing surface MS. As shown in FIG. 5(a) and FIG. 5(b), under the assumption that the processing unit area BSA#2 is stationary (i.e., not moving) on ​​the printing surface MS, the galvanometer mirror 2156 may deflect the processing light EL#2 so that the target irradiation area EA#2 moves along multiple scanning directions within the processing unit area BSA#2.

[0127] 4A, 5A, and 5B, the operation of periodically moving the target irradiation area EA#2 on the printing surface MS may be referred to as a wobbling operation. In other words, the operation of periodically moving (or deflecting) the processing light EL#2 so as to periodically move the target irradiation area EA#2 on the printing surface MS may be referred to as a wobbling operation.

[0128] Typically, the processing unit area BSA#1 and the processing unit area BSA#2 coincide. In other words, the processing unit area BSA#1 is identical to the processing unit area BSA#2. Therefore, the galvanometer mirror 2156 may be considered to deflect the processing light EL#2 so that the target irradiation area EA#2 moves within the processing unit area BSA#1. The galvanometer mirror 2146 may be considered to deflect the processing light EL#1 so that the target irradiation area EA#1 moves within the processing unit area BSA#2. However, the processing unit area BSA#1 and the processing unit area BSA#2 may be partially different.

[0129] When the processing light EL#2 is irradiated onto the printing surface MS in units of the processing unit area BSA#2, a molten pool MP#2 is formed in at least a part of the processing unit area BSA#2. As a result, a molded object is formed within the processing unit area BSA#2. As described above, the processing unit area BSA#2 is an area having a width in a direction intersecting the movement direction of the processing unit area BSA#2 on the printing surface MS (specifically, the direction in which the target movement trajectory MT0 extends). In this case, a molded object having a width along the direction intersecting the target movement trajectory MT0 of the processing unit area BSA#2 is formed on the printing surface MS. For example, in the example shown in FIGS. 4( a) and 4(b), a molded object having a width along the X-axis direction and extending along the Y-axis direction is formed. For example, in the example shown in FIGS. 5(a) and 5(c), a molded object having a width along the X-axis direction and extending along the Y-axis direction is formed.

[0130] When the processing light EL#2 is irradiated onto the printing surface MS in units of processing unit areas BSA#2, the processing unit areas BSA#2 are scanned with the processing light EL#2 by the galvanometer mirror 2156. Therefore, compared to when the processing light EL#2 is irradiated onto the printing surface MS without using the galvanometer mirror 2156, the amount of energy transmitted from the processing light EL#2 to the processing unit areas BSA#2 is less likely to vary within the processing unit areas BSA#2. In other words, the amount of energy transmitted from the processing light EL#2 to the processing unit areas BSA#2 can be made uniform. As a result, the processing system SYS can form a model on the printing surface MS with relatively high printing accuracy.

[0131] However, the machining system SYS does not have to irradiate the manufacturing surface MS with the processing light EL#2 in units of the processing unit area BSA#2. The machining system SYS may irradiate the manufacturing surface MS with the processing light EL#2 without using the galvanometer mirror 2156. In this case, the target irradiation area EA#2 may move on the manufacturing surface MS in accordance with the movement of at least one of the machining head 21 and the stage 31.

[0132] Referring again to FIG. 3 , the processing light EL#2 reflected by the parallel plate 2152 is incident on the power meter 2153. The power meter 2153 is a specific example of an electrical component used to control the processing light EL#2. Specifically, the power meter 2153 can detect the intensity of the processing light EL#2 incident on the power meter 2153. For example, the power meter 2153 may include a light-receiving element that detects the processing light EL#2 as light. Alternatively, the higher the intensity of the processing light EL#2, the greater the amount of energy generated by the processing light EL#2. As a result, the amount of heat generated by the processing light EL#2 increases. Therefore, the power meter 2153 may detect the intensity of the processing light EL#2 by detecting the processing light EL#2 as heat. In this case, the power meter 2153 may include a heat-detecting element that detects the heat of the processing light EL#2.

[0133] As described above, the processing light EL#2 reflected by the parallel plate 2152 is incident on the power meter 2153. Therefore, the power meter 2153 detects the intensity of the processing light EL#2 reflected by the parallel plate 2152. Because the parallel plate 2152 is disposed on the optical path of the processing light EL#2 between the light source 4#2 and the galvanometer mirror 2156, the power meter 2153 may be considered to detect the intensity of the processing light EL#2 traveling along the optical path between the light source 4#2 and the galvanometer mirror 2156. In this case, the power meter 2153 can stably detect the intensity of the processing light EL#2 without being affected by the deflection of the processing light EL#2 by the galvanometer mirror 2156. However, the location of the power meter 2153 is not limited to the example shown in FIG. 3 . For example, the power meter 2153 may detect the intensity of the processing light EL#2 traveling along the optical path between the galvanometer mirror 2156 and the printing surface MS. The power meter 2153 may detect the intensity of the processing light EL#2 traveling along the optical path within the galvanometer mirror 2156.

[0134] The detection result of the power meter 2153 is output to the control unit 7. The control unit 7 may control (in other words, change) the intensity of the processing light EL#2 based on the detection result of the power meter 2153 (i.e., the detection result of the intensity of the processing light EL#2). For example, the control unit 7 may control the intensity of the processing light EL#2 so that the intensity of the processing light EL#2 on the printing surface MS becomes a desired intensity. To control the intensity of the processing light EL#2, for example, the control unit 7 may control the light source 4#2 based on the detection result of the power meter 2153 to change the intensity of the processing light EL#2 emitted from the light source 4#2. As a result, the processing system SYS can appropriately print a model on the printing surface MS by irradiating the printing surface MS with processing light EL#2 having an appropriate intensity.

[0135] As described above, the processing light EL#2 has an intensity capable of melting the shaping material M. Therefore, the processing light EL#2 incident on the power meter 2153 may have an intensity capable of melting the shaping material M. However, if the processing light EL#2 having an intensity capable of melting the shaping material M is incident on the power meter 2153, the power meter 2153 may be damaged by the processing light EL#2. Therefore, the processing light EL#2 may be incident on the power meter 2153 with an intensity not high enough to damage the power meter 2153. In other words, the second optical system 215 may weaken the intensity of the processing light EL#2 incident on the power meter 2153 so that the processing light EL#2 having an intensity not high enough to damage the power meter 2153 is incident on the power meter 2153.

[0136] For example, in order to weaken the intensity of the processing light EL#2 incident on the power meter 2153, the reflectivity of the parallel plate 2152 for the processing light EL#2 may be set to an appropriate value. Specifically, the lower the reflectivity of the parallel plate 2152 for the processing light EL#2, the lower the intensity of the processing light EL#2 incident on the power meter 2153. Therefore, the reflectivity of the parallel plate 2152 may be set to a value low enough to realize a state in which the processing light EL#2, having an intensity not high enough to damage the power meter 2153, is incident on the power meter 2153. For example, the reflectivity of the parallel plate 2152 may be less than 10%. For example, the reflectivity of the parallel plate 2152 may be less than a few percent. Plain glass may be used as the parallel plate 2152 with such low reflectivity.

[0137] For example, in order to weaken the intensity of the processing light EL#2 incident on the power meter 2153, the second optical system 215 may cause the processing light EL#2 to be incident on the power meter 2153 via multiple parallel plates 2152. Specifically, the processing light EL#2 reflected multiple times by each of the multiple parallel plates 2152 may be incident on the power meter 2153. In this case, the intensity of the processing light EL#2 reflected multiple times by each of the multiple parallel plates 2152 is weaker than the intensity of the processing light EL#2 reflected once by a single parallel plate 2152. Therefore, there is a high possibility that the processing light EL#2 having an intensity not high enough to damage the power meter 2153 will be incident on the power meter 2153.

[0138] A desired coating treatment may be applied to the surface of the parallel plate 2152 (particularly, at least one of the incident surface onto which the processing light EL#2 is incident and the reflecting surface onto which the processing light EL#2 is reflected). For example, the surface of the parallel plate 2152 may be subjected to anti-reflection coating (AR).

[0139] The third optical system 216 includes a prism mirror 2161 and an fθ lens 2162 .

[0140] Processing light EL#1 emitted from the first optical system 214 and processing light EL#2 emitted from the second optical system 215 are each incident on a prism mirror 2161. The prism mirror 2161 reflects each of processing light EL#1 and EL#2 toward an fθ lens 2162. The prism mirror 2161 reflects processing light EL#1 and EL#2, which are incident on the prism mirror 2161 from different directions, in the same direction (specifically, toward the fθ lens 2162).

[0141] Furthermore, if the processing light EL#1 emitted from the first optical system 214 and the processing light EL#2 emitted from the second optical system 215 can each be directly incident on the fθ lens 2162, the third optical system 216 does not need to be equipped with a prism mirror 2161.

[0142] The fθ lens 2162 is an optical system for emitting each of the processing lights EL#1 and EL#2 reflected by the prism mirror 2161 toward the printing surface MS. In other words, the fθ lens 2162 is an optical system for irradiating each of the processing lights EL#1 and EL#2 reflected by the prism mirror 2161 onto the printing surface MS. As a result, the processing lights EL#1 and EL#2 that have passed through the fθ lens 2162 are irradiated onto the printing surface MS.

[0143] The fθ lens 2162 may be an optical element capable of focusing each of the processing beams EL#1 and EL#2 on a focusing surface. In this case, the fθ lens 2162 may be referred to as a focusing optical system. The focusing surface of the fθ lens 2162 may be set, for example, on the printing surface MS. In this case, the third optical system 216 may be considered to have a focusing optical system whose projection characteristic is fθ. However, the third optical system 216 may also have a focusing optical system whose projection characteristic is different from fθ. For example, the third optical system 216 may have a focusing optical system whose projection characteristic is f tan θ. For example, the third optical system 216 may have a focusing optical system whose projection characteristic is f sin θ.

[0144] The optical axis AX of the fθ lens 2162 is an axis along the Z-axis. Therefore, the fθ lens 2162 emits each of the processing lights EL#1 and EL#2 along the Z-axis direction. In this case, the irradiation direction of the processing light EL#1 and the irradiation direction of the processing light EL#2 may be the same direction. The irradiation direction of the processing light EL#1 and the irradiation direction of the processing light EL#2 may both be the Z-axis direction. The irradiation direction of the processing light EL#1 and the irradiation direction of the processing light EL#2 may both be directions along the optical axis AX of the fθ lens 2162. However, the irradiation direction of the processing light EL#1 and the irradiation direction of the processing light EL#2 do not have to be the same direction. The irradiation direction of the processing light EL#1 and the irradiation direction of the processing light EL#2 may be mutually different directions.

[0145] (2) Operation of the Machining System SYS Next, the operation of the machining system SYS will be described.

[0146] (2-1) Additional Processing Operation Performed by the Processing System SYS First, the additional processing (additional processing operation) performed by the processing system SYS on the workpiece W will be described. The additional processing performed on the workpiece W corresponds to an operation of forming a structure by adding a structure that is integrated with (or separable from) the workpiece W to the workpiece W. For convenience of explanation, the following describes the additional processing of forming a three-dimensional structure ST, which is a structure having a desired shape. As described above, the processing system SYS forms the three-dimensional structure ST by performing additional processing based on the laser build-up welding method. For this reason, the processing system SYS may form the three-dimensional structure ST by performing existing additional processing that complies with the laser build-up welding method. Below, an example of the operation of forming the three-dimensional structure ST using the laser build-up welding method will be briefly described.

[0147] The processing system SYS forms a three-dimensional structure ST on a workpiece W based on three-dimensional model data (in other words, three-dimensional model information) of the three-dimensional structure ST to be formed. Measurement data of a three-dimensional object measured by at least one of a measuring device installed within the processing system SYS and a three-dimensional shape measuring device installed separately from the processing system SYS may be used as the three-dimensional model data. To form the three-dimensional structure ST, the processing system SYS sequentially forms, for example, multiple layered substructures (hereinafter referred to as "structural layers") SL arranged along the Z-axis direction. For example, the processing system SYS sequentially forms multiple structural layers SL layer by layer based on data of multiple layers obtained by slicing a three-dimensional model of the three-dimensional structure ST along the Z-axis direction. As a result, a three-dimensional structure ST is formed, which is a layered structure in which multiple structural layers SL are stacked. The structural layers SL do not necessarily have to be layered structures. The flow of operations for forming a three-dimensional structure ST by sequentially forming a plurality of structural layers SL one by one will be described below.

[0148] First, the operation of forming each structure layer SL will be described with reference to FIGS. 6A to 6E. Under the control of the control unit 7, the processing system SYS moves at least one of the processing head 21 and the stage 31 so that processing unit areas BSA#1 and BSA#2 are set in desired areas on the printing surface MS corresponding to the surface of the workpiece W or the surface of the printed structure layer SL. Then, the irradiation optical system 211 irradiates the processing unit areas BSA#1 and BSA#2 with processing beams EL#1 and EL#2, respectively. At this time, the focusing positions CP#1 and CP#2 at which the processing beams EL#1 and EL#2 are focused in the Z-axis direction may coincide with the printing surface MS. Alternatively, the focusing positions CP#1 and CP#2 at which the processing beams EL#1 and EL#2 are focused in the Z-axis direction may be offset from the printing surface MS. As a result, as shown in Figure 6(a), molten pools MP#1 and MP#2 are formed on the building surface MS irradiated with the processing beams EL#1 and EL#2, respectively. Furthermore, as shown in Figure 6(b), the processing system SYS supplies the building material M from the material nozzle 212 under the control of the control unit 7. As a result, the building material M is supplied to each of the molten pools MP#1 and MP#2. The building material M supplied to the molten pool MP#1 is melted by the processing beam EL#1 irradiated onto the molten pool MP#1. Similarly, the building material M supplied to the molten pool MP#2 is melted by the processing beam EL#2 irradiated onto the molten pool MP#2.

[0149] Furthermore, the irradiation optical system 211 uses the galvanometer mirrors 2146 and 2156 to move the target irradiation areas EA#1 and EA#2 within the machining unit areas BSA#1 and BSA#2, respectively. That is, the irradiation optical system 211 uses the galvanometer mirrors 2146 and 2156 to scan the machining unit areas BSA#1 and BSA#2 with the machining beams EL#1 and EL#2, respectively. When the target irradiation area EA#1 moves and the machining beam EL#1 is no longer irradiated onto the molten pool MP#1, the molten build material M in the molten pool MP#1 cools and solidifies (i.e., solidifies). Similarly, when the target irradiation area EA#2 moves and the machining beam EL#2 is no longer irradiated onto the molten pool MP#2, the molten build material M in the molten pool MP#2 cools and solidifies (i.e., solidifies). Furthermore, as the target irradiation areas EA#1 and EA#2 move, the molten pools MP#1 and MP#2 also move. As a result, as shown in Figure 6(c), within the processing unit areas BSA#1 and BSA#2 through which the molten pools MP#1 and MP#2 move, a molded object made of the solidified mold material M is deposited on the mold surface MS.

[0150] 6(c), for ease of explanation, the object made of the solidified building material M in the processing unit area BSA#1 and the object made of the solidified building material M in the processing unit area BSA#2 are physically separated. However, the object made of the solidified building material M in the processing unit area BSA#1 and the object made of the solidified building material M in the processing unit area BSA#2 may be integrated. In particular, when the processing unit areas BSA#1 and BSA#2 coincide (or partially overlap), the object made of the solidified building material M in the processing unit area BSA#1 and the object made of the solidified building material M in the processing unit area BSA#2 may be integrated. During a period in which the target irradiation areas EA#1 and EA#2 are moving within the physically separated machining unit areas BSA#1 and BSA#2, respectively, the machining system SYS may move at least one of the machining head 21 and the stage 31 so that the machining unit areas BSA#1 and BSA#2 move on the printing surface MS. In other words, the machining system SYS may move the target irradiation areas EA#1 and EA#2 within the machining unit areas BSA#1 and BSA#2, respectively, and move the machining unit areas BSA#1 and BSA#2 on the printing surface MS in parallel.

[0151] Alternatively, during the period when the target irradiation areas EA#1 and EA#2 are moving within the machining unit areas BSA#1 and BSA#2, respectively, the machining system SYS does not have to move the machining head 21 and the stage 31 so that the machining unit areas BSA#1 and BSA#2 do not move on the printing surface MS. In this case, after the additional machining (i.e., printing) within the machining unit areas BSA#1 and BSA#2 is completed, the machining system SYS may move at least one of the machining head 21 and the stage 31 so that the machining unit areas BSA#1 and BSA#2 are set in another area on the printing surface MS. In other words, after the additional machining (i.e., printing) within the machining unit areas BSA#1 and BSA#2 is completed, the machining system SYS may move at least one of the machining head 21 and the stage 31 so that the machining unit areas BSA#1 and BSA#2 move on the printing surface MS. In this case, the machining system SYS may move at least one of the machining head 21 and the stage 31 so that the area on the printing surface MS where the machining unit areas BSA#1 and BSA#2 have already been set (i.e., the area where additional machining has already been performed) and the area on the printing surface MS where the machining unit areas BSA#1 and BSA#2 have newly been set (i.e., the area where additional machining will now be performed) are adjacent to each other. In particular, the machining system SYS may move at least one of the machining head 21 and the stage 31 so that the area on the printing surface MS where the machining unit areas BSA#1 and BSA#2 have already been set do not overlap with the area on the printing surface MS where the machining unit areas BSA#1 and BSA#2 have newly been set. However, the processing system SYS may move at least one of the processing head 21 and the stage 31 so that the area on the printing surface MS where processing unit areas BSA#1 and BSA#2 have already been set partially overlaps with the area on the printing surface MS where processing unit areas BSA#1 and BSA#2 have newly been set.

[0152] The machining system SYS repeats a series of manufacturing processes, including forming a molten pool MP#1 by irradiating the machining unit area BSA#1 with the machining light EL#1, forming a molten pool MP#2 by irradiating the machining unit area BSA#2 with the machining light EL#2, supplying the manufacturing material M to the molten pools MP#1 and MP#2, melting the supplied manufacturing material M, and solidifying the molten manufacturing material M, while moving the machining unit areas BSA#1 and BSA#2 along the target movement trajectory MTO on the manufacturing surface MS, as shown in FIG. 6( d ). In this case, as the machining unit areas BSA#1 and BSA#2 move, a manufactured object having a width in a direction intersecting the target movement trajectory MTO is manufactured on the manufacturing surface MS. For example, when the machining unit areas BSA#1 and BSA#2 move as shown in FIGS. 4( a ) and 4 ( b ), a manufactured object having a width in the X-axis direction and extending in the Y-axis direction is manufactured. For example, when the processing unit areas BSA#1 and BSA#2 move as shown in Figures 5(a) and 5(c), respectively, a structure having a width along the X-axis direction and extending along the Y-axis direction is formed.

[0153] As a result, as shown in Fig. 6(e), a structure layer SL corresponding to a structured object, which is an aggregate of the melted and then solidified building material M, is formed on the building surface MS. That is, a structure layer SL corresponding to an aggregate of objects formed on the building surface MS in a pattern corresponding to the target movement trajectories MT0 of the processing unit areas BSA#1 and BSA#2 is formed. That is, a structure layer SL having a shape corresponding to the target movement trajectories MT0 of the processing unit areas BSA#1 and BSA#2 in plan view is formed.

[0154] Note that when the target irradiation area EA#1 is set in an area where it is not desired to form an object, the processing system SYS does not have to irradiate the target irradiation area EA#1 with the processing light EL#1. Alternatively, the processing system SYS may irradiate the target irradiation area EA#1 with the processing light EL#1 and stop the supply of the building material M. Alternatively, the processing system SYS may supply the building material M to the target irradiation area EA#1 and irradiate the target irradiation area EA#1 with the processing light EL#1 at an intensity that does not cause the formation of a molten pool MP. The same applies when the target irradiation area EA#2 is set in an area where it is not desired to form an object.

[0155] The target movement trajectories MT0 of the machining unit areas BSA#1 and BSA#2 may be referred to as machining paths (in other words, tool paths). In this case, the control unit 7 may move at least one of the machining head 21 and the stage 31 based on path information indicating the target movement trajectories MT0 (i.e., path information indicating the machining paths) so that each of the machining unit areas BSA#1 and BSA#2 moves along the target movement trajectories MT0 on the printing surface MS.

[0156] In addition to indicating the target movement trajectory MTO, the path information may also include information regarding a target value of the width of the object (hereinafter referred to as the "target width"). The target width may also be referred to as a line width or a bead width. Specifically, as described above, as the processing unit areas BSA#1 and BSA#2 move along the target movement trajectory MTO, an object having a width along a direction intersecting the target movement trajectory MTO is formed on the printing surface MS. For example, when the processing unit areas BSA#1 and BSA#2 move along the Y-axis direction as shown in FIG. 7A, a linear object having a width along the X-axis direction and extending along the Y-axis direction is formed on the printing surface MS as shown in FIG. 7B. The structure layer SL described above corresponds to a collection of linear objects as shown in FIG. 7B. In this case, the path information may also include information regarding a target value of the width D of the linear object (i.e., the target width), as shown in FIG. 7B. That is, the pass information may include information regarding the width of a linear object (i.e., a line) to be formed on the formation surface MS. Note that the information regarding the target width of the linear object (i.e., information regarding the width of the line to be formed) may be referred to as line width information.

[0157] In this case, the control unit 7 may control the galvanometer mirrors 2146 and 2156, respectively, based on the line width information so that the target irradiation areas EA#1 and EA#2 move within the processing unit areas BSA#1 and BSA#2, respectively. For example, the control unit 7 may control the galvanometer mirrors 2146 and 2156, respectively, so that the target irradiation areas EA#1 and EA#2 move periodically within the line width indicated by the line width information. In other words, the control unit 7 may control the galvanometer mirrors 2146 and 2156, respectively, so that the target irradiation areas EA#1 and EA#2 do not deviate outside the line width indicated by the line width information. In other words, the control unit 7 may control the galvanometer mirrors 2146 and 2156, respectively, so that the target irradiation areas EA#1 and EA#2 move periodically within the target width of the object indicated by the line width information. That is, the control unit 7 may control the galvanometer mirrors 2146 and 2156 so that the target irradiation areas EA#1 and EA#2 do not deviate outside the target width of the object indicated by the line width information.

[0158] As a result, the molten pools MP#1 and MP#2 also move periodically inside the line width indicated by the line width information. In other words, the molten pools MP#1 and MP#2 do not deviate outside the line width indicated by the line width information. In other words, the molten pools MP#1 and MP#2 move periodically inside the target width of the object indicated by the line width information. In other words, the molten pools MP#1 and MP#2 do not deviate outside the target width of the object indicated by the line width information. This allows the machining system SYS to appropriately form a linear object having the target width indicated by the line width information.

[0159] The line width indicated by the line width information (i.e., the target width of the object) may be the same as the width of each of the processing unit areas BSA#1 and BSA#2. Alternatively, the line width indicated by the line width information (i.e., the target width of the object) may be smaller than the width of each of the processing unit areas BSA#1 and BSA#2. The size in the X-axis direction and the size in the Y-axis direction of each of the processing unit areas BSA#1 and BSA#2 may be several millimeters. However, the size of each of the processing unit areas BSA#1 and BSA#2 is not limited to several millimeters.

[0160] The machining system SYS repeatedly performs operations for forming such a structure layer SL based on the three-dimensional model data under the control of the control unit 7. Specifically, before performing operations for forming the structure layer SL, the control unit 7 first slices the three-dimensional model data at the layer pitch to create slice data. The machining system SYS performs operations for forming the first structure layer SL#1 on the build surface MS corresponding to the surface of the workpiece W based on the slice data corresponding to the structure layer SL#1. Specifically, the control unit 7 acquires path information for forming the first structure layer SL#1, which is generated based on the slice data corresponding to the structure layer SL#1. Note that the control unit 7 may generate the path information after or before the machining system SYS starts additional processing. Thereafter, the control unit 7 controls the machining unit 2 and the stage unit 3 based on the path information to form the first structure layer SL#1. As a result, the structure layer SL#1 is formed on the build surface MS as shown in FIG. 8A. Thereafter, the machining system SYS sets the surface (i.e., the upper surface) of the structural layer SL#1 as a new printing surface MS, and then prints a second structural layer SL#2 on the new printing surface MS. To print the structural layer SL#2, the control unit 7 first controls at least one of the head drive system 22 and the stage drive system 32 so that the machining head 21 moves along the Z axis relative to the stage 31. Specifically, the control unit 7 controls at least one of the head drive system 22 and the stage drive system 32 to move the machining head 21 toward the +Z side and / or move the stage 31 toward the −Z side so that the machining unit areas BSA#1 and BSA#2 are set on the surface of the structural layer SL#1 (i.e., the new printing surface MS). Thereafter, under the control of the control unit 7, the machining system SYS prints the structural layer SL#2 on the structural layer SL#1 based on the slice data corresponding to the structural layer SL#2, using operations similar to those used to print the structural layer SL#1. As a result, a structural layer SL#2 is formed as shown in Fig. 8(b) . Thereafter, the same operation is repeated until all structural layers SL that constitute the three-dimensional structure ST to be formed on the workpiece W are formed.As a result, as shown in FIG. 8C, a three-dimensional structure ST is formed by a layered structure in which a plurality of structural layers SL are stacked.

[0161] (2-2) Weld Pool Feedback Control Operation Based on Weld Pool Image IMG The machining system SYS may perform weld pool feedback control operation based on the weld pool image IMG generated by the imaging unit 8 in parallel with the above-mentioned additional machining operation. In other words, the machining system SYS may perform weld pool feedback control operation during at least a portion of the period during which the above-mentioned additional machining operation is being performed. The weld pool feedback control operation is an operation for controlling the machining unit 2 based on the weld pool image IMG so that the size of the weld pool area MPA in the weld pool image IMG becomes the target size TS. The weld pool area MPA will be described in detail later.

[0162] The flow of the weld pool feedback control operation will be described below with reference to Fig. 9. Fig. 9 is a flowchart showing the flow of the weld pool feedback control operation.

[0163] 9 , the control unit 7 acquires a molten pool image IMG from the imaging unit 8 (step S11). Specifically, the imaging unit 8 acquires an image of the workpiece W or the structural layer SL on which molten pools MP#1 and MP#2 are formed. That is, the imaging unit 8 acquires images of the molten pools MP#1 and MP#2. As a result, the imaging unit 8 generates a molten pool image IMG in which the molten pools MP#1 and MP#2 are captured. The imaging unit 8 outputs the generated molten pool image IMG to the control unit 7. As a result, the control unit 7 acquires the molten pool image IMG.

[0164] The imaging unit 8 images the molten pools MP#1 and MP#2 so that they fall within the imaging range of the imaging unit 8. Specifically, the imaging unit 8 may be aligned with the workpiece W or the structural layer SL on which the molten pools MP#1 and MP#2 are formed so that the molten pools MP#1 and MP#2 fall within the imaging range of the imaging unit 8. The imaging unit 8 may be aligned with the machining head 21 so that the molten pools MP#1 and MP#2 formed on the build surface MS by the machining head 21 fall within the imaging range of the imaging unit 8. As a result, the imaging unit 8 can properly image the molten pools MP#1 and MP#2.

[0165] As described above, the galvanometer mirrors 2146 and 2156 cause the molten pools MP#1 and MP#2 to move within the machining unit areas BSA#1 and BSA#2, respectively. In this case, the imaging unit 8 may image the molten pool MP so that the movement ranges of the molten pools MP#1 and MP#2 fall within the imaging range of the imaging unit 8. In other words, the imaging unit 8 may image the molten pool MP so that the machining unit areas BSA#1 and BSA#2 fall within the imaging range of the imaging unit 8. Specifically, the imaging unit 8 may be aligned with the workpiece W or structural layer SL in which the molten pool MP is formed so that the movement ranges of the molten pools MP#1 and MP#2 (i.e., the machining unit areas BSA#1 and BSA#2) fall within the imaging range of the imaging unit 8. The imaging unit 8 may be aligned with the machining head 21 so that the movement ranges of the molten pools MP#1 and MP#2 formed on the build surface MS by the machining head 21 (i.e., the machining unit areas BSA#1 and BSA#2) fall within the imaging range of the imaging unit 8. As a result, the imaging unit 8 can properly capture images of the molten pools MP#1 and MP#2 moving within the machining unit areas BSA#1 and BSA#2, respectively.

[0166] The imaging unit 8 may repeatedly capture images of the workpiece W or the structural layer SL on which the molten pool MP is formed at a predetermined imaging rate. That is, the imaging unit 8 may capture images of the workpiece W or the structural layer SL on which the molten pool MP is formed multiple times at the predetermined imaging rate. The imaging rate may be an index value indicating the number of times the imaging unit 8 captures images of the workpiece W or the structural layer SL per unit time (e.g., per second). In other words, the imaging unit 8 may repeatedly capture images of the workpiece W or the structural layer SL each time a predetermined imaging cycle elapses. For example, the imaging unit 8 may capture an image of the workpiece W or the structural layer SL at a first time, and then capture the image of the workpiece W or the structural layer SL at a second time, a predetermined imaging cycle after the first time. The imaging cycle may be the reciprocal of the imaging rate. In this case, the imaging unit 8 may generate multiple molten pool images IMG as time-series data. The control unit 7 may acquire multiple molten pool images IMG as time-series data.

[0167] Even during the period when the imaging unit 8 repeatedly images the workpiece W or the structure layer SL, the galvanometer mirror 2146 moves the molten pool MP#1 within the machining unit area BSA#1. In this case, the imaging unit 8 may image the molten pool MP#1 formed at a first position on the build surface MS at a first time, and then image the molten pool MP#1 formed at a second position on the build surface MS different from the first position at a second time different from the first time. In other words, the imaging unit 8 may image the molten pool MP#1 appearing at the first position on the build surface MS at a first time, and then image the molten pool MP#1 appearing at the second position on the build surface MS at a second time. As a result, the multiple molten pool images IMG generated by the imaging unit 8 may include a molten pool image IMG in which the molten pool MP#1 formed at the first position on the build surface MS is captured, and a molten pool image IMG in which the molten pool MP#1 formed at the second position on the build surface MS is captured. In other words, the multiple molten pool images IMG may include a molten pool image IMG showing a molten pool MP#1 formed at a first position on the build surface MS, and a molten pool image IMG showing a molten pool MP#1 formed at a second position on the build surface MS. The multiple molten pool images IMG may include a molten pool image IMG generated by imaging the molten pool MP#1 formed at the first position on the build surface MS, and a molten pool image IMG generated by imaging the molten pool MP#1 formed at the second position on the build surface MS.

[0168] Similarly, while the imaging unit 8 repeatedly images the workpiece W or the structure layer SL, the galvanometer mirror 2156 moves the molten pool MP#2 within the machining unit area BSA#2. In this case, the imaging unit 8 may image the molten pool MP#2 formed at a third position on the build surface MS at a first time, and then image the molten pool MP#2 formed at a fourth position on the build surface MS that is different from the third position at a second time that is different from the first time. In other words, the imaging unit 8 may image the molten pool MP#2 that appears at the third position on the build surface MS at a first time, and then image the molten pool MP#2 that appears at the fourth position on the build surface MS at a second time. As a result, the multiple molten pool images IMG generated by the imaging unit 8 may include a molten pool image IMG in which the molten pool MP#2 formed at the third position on the build surface MS is captured, and a molten pool image IMG in which the molten pool MP#2 formed at the fourth position on the build surface MS is captured. In other words, the multiple molten pool images IMG may include a molten pool image IMG showing the molten pool MP#2 formed at a third position on the build surface MS, and a molten pool image IMG showing the molten pool MP#2 formed at a fourth position on the build surface MS. The multiple molten pool images IMG may include a molten pool image IMG generated by imaging the molten pool MP#2 formed at the third position on the build surface MS, and a molten pool image IMG generated by imaging the molten pool MP#2 formed at the fourth position on the build surface MS.

[0169] Note that, when the imaging unit 8 repeatedly captures images of the workpiece W or the structural layer SL, the imaging unit 8 may be considered to be exposing the imaging element to light from the workpiece W or the structural layer SL multiple times. In this case, the multiple exposures of the imaging element may be referred to as multiple exposures. That is, the imaging unit 8 may generate multiple molten pool images IMG as time-series data by performing multiple exposures of the imaging element. In other words, the imaging unit 8 may generate multiple molten pool images IMG as time-series data by performing multiple exposures of the molten pool MP using the imaging element. That is, the imaging unit 8 may generate multiple molten pool images IMG as a result of the multiple exposures by performing multiple exposures of the molten pool MP using the imaging element.

[0170] Alternatively, when the imaging unit 8 repeatedly captures images of the workpiece W or the structural layer SL, the imaging unit 8 may expose the imaging element to light from the workpiece W or the structural layer SL multiple times in a single imaging operation to capture a single weld pool image IMG. In this case, the multiple exposures of the imaging element in a single imaging operation to capture a single weld pool image IMG may be referred to as multiple exposures. In other words, the imaging unit 8 may generate a single weld pool image IMG by performing multiple exposures of the imaging element. Furthermore, the imaging unit 8 may generate multiple weld pool images IMG as time-series data by repeatedly performing multiple exposures of the imaging element to generate a single weld pool image IMG. In other words, the imaging unit 8 may generate multiple weld pool images IMG as a result of the multiple exposures by performing multiple exposures of the weld pool MP using the imaging element.

[0171] Thereafter, the control unit 7 generates weld pool image information MPI based on at least one weld pool image IMG acquired in step S11 (step S12). The weld pool image information MPI is information about the weld pools MP#1 and MP#2 that appear in the weld pool image IMG.

[0172] The control unit 7 may generate information related to the weld pool area MPA as an example of the weld pool image information MPI. The weld pool area MPA may include an area in the weld pool image IMG where the weld pools MP#1 and MP#2 are reflected, as shown in FIG. 10 showing the weld pool image IMG.

[0173] To generate information about the weld pool area MPA, the control unit 7 may use at least two of the multiple weld pool images IMG acquired as time-series data in step S10. In other words, the control unit 7 may generate information about the weld pool area MPA by using multiple weld pool images IMG corresponding to at least some of the multiple weld pool images IMG acquired as time-series data in step S10.

[0174] Specifically, the left side of Figure 11 shows multiple weld pool images IMG acquired as time-series data. As shown on the left side of Figure 11, when the weld pool MP#1 is moved by the galvanometer mirror 2146, the position at which the weld pool MP#1 is captured may change among the multiple weld pool images IMG. This is because, as described above, when the weld pool MP#1 is moved by the galvanometer mirror 2146, the imaging unit 8 may capture an image of the weld pool MP#1 formed at a first position on the build surface MS at a first time, and then capture an image of the weld pool MP#1 formed at a second position on the build surface MS different from the first time at a second time different from the first time. In particular, when the exposure time of the imaging unit 8 is shorter than a certain time, the position at which the weld pool MP#1 is captured may change among the multiple weld pool images IMG. For the same reason, when the weld pool MP#2 is moved by the galvanometer mirror 2156, the position at which the weld pool MP#2 is captured may change among the multiple weld pool images IMG.

[0175] In this case, the control unit 7 may generate an added image IMG_C by adding at least two consecutive weld pool images IMG out of the multiple weld pool images IMG acquired in step S10 to generate information about the weld pool area MPA, as shown in Fig. 11. In other words, the control unit 7 may generate an added image IMG_C by combining at least two consecutive weld pool images IMG. The added image IMG_C may also be referred to as a composite image.

[0176] Specifically, the control unit 7 may add at least two successive weld pool images IMG in pixel units. For example, the control unit 7 may add the signal values ​​of at least two successive weld pool images IMG in pixel units. An example of the signal value of the weld pool image IMG is a value related to brightness (i.e., brightness value). The number of weld pool images IMG to be added may be set in advance. The number of weld pool images IMG to be added may be set as appropriate by the control unit 7. The number of added frames, which is the number of weld pool images IMG to be added, may be set as appropriate by the user of the machining system SYS.

[0177] In this case, the additive image IMG_C may be an image in which the signal value of each pixel in the additive image IMG_C is the sum of the signal values ​​of each pixel in the at least two added weld pool images IMG. Specifically, the additive image IMG_C may be an image in which the signal value of the pixel in the xth row and yth column of the additive image IMG_C is the sum of the signal values ​​of the pixel in the xth row and yth column of the at least two added weld pool images IMG. Note that x is a variable that is 1 or greater and indicates an integer that is equal to or less than the total number of horizontal pixels in the additive image IMG_C and the weld pool image IMG. y is a variable that is 1 or greater and indicates an integer that is equal to or less than the total number of vertical pixels in the additive image IMG_C and the weld pool image IMG.

[0178] Alternatively, the additive image IMG_C may be an image in which the signal value of each pixel in the additive image IMG_C is the average value of the signal values ​​of each pixel in the at least two added weld pool images IMG. For example, the additive image IMG_C may be an image in which the signal value of the pixel in the xth row and yth column of the additive image IMG_C is the average value of the signal values ​​of the pixels in the xth row and yth column of the at least two added weld pool images IMG (i.e., the value obtained by dividing the sum of the signal values ​​by the number of added frames). In this case, the control unit 7 may generate the additive image IMG_C by calculating the sum of the signal values ​​of each pixel in the at least two weld pool images IMG and then dividing the calculated sum by the number of added frames. Alternatively, the control unit 7 may generate the additive image IMG_C by dividing the signal value of each pixel in the at least two weld pool images IMG by the number of added frames and then calculating the sum of the signal values ​​of each pixel.

[0179] Alternatively, the additive image IMG_C may be an image in which the signal value of each pixel in the additive image IMG_C is a moving average of the signal values ​​of each pixel in at least two added weld pool images IMG. For example, the control unit 7 may generate the additive image IMG_C by calculating the moving average of the signal values ​​of each pixel in at least two most recently acquired weld pool images IMG. As an example, the control unit 7 may generate a first additive image IMG_C by calculating the moving average of the signal values ​​of each pixel in ten weld pool images IMG, each having frames 1 through 10 assigned as indexes. Thereafter, the control unit 7 may generate a second additive image IMG_C by calculating the moving average of the signal values ​​of each pixel in ten weld pool images IMG, each having frames 2 through 11 assigned as indexes. Thereafter, the control unit 7 may generate a third additive image IMG_C by calculating the moving average of the signal values ​​of each pixel in ten weld pool images IMG, each having frames 3 through 12 assigned as indexes. Thereafter, the control unit 7 may generate an added image IMG_C in a similar manner.

[0180] The control unit 7 typically acquires the weld pool image IMG represented by a digital signal from the imaging unit 8. In this case, the control unit 7 may add together the multiple weld pool images IMG by adding together multiple digital signals representing the multiple weld pool images IMG. For example, the control unit 7 may add together the multiple weld pool images IMG by using an adder (i.e., a hardware adder) that adds input digital signals. For example, the control unit 7 may add together the multiple weld pool images IMG by storing the digital signals in a buffer and then adding the digital signals stored in the buffer (i.e., adding the digital signals as software processing). Alternatively, the control unit 7 may add together the multiple weld pool images IMG by performing predetermined image processing on the multiple weld pool images IMG and then adding together multiple digital signals representing the multiple weld pool images IMG that have been subjected to the predetermined image processing. Examples of the predetermined signal processing include at least one of gamma processing, noise reduction processing, and HDR (High Dynamic Range) processing.

[0181] Alternatively, the control unit 7 may acquire the weld pool image IMG represented by an analog signal from the imaging unit 8. In this case, the control unit 7 may add together the multiple weld pool images IMG by adding together multiple analog signals representing the multiple weld pool images IMG. Alternatively, the control unit 7 may convert the analog signal into a digital signal. Thereafter, the control unit 7 may add together the multiple weld pool images IMG by adding together multiple digital signals representing the multiple weld pool images IMG, similar to the case of acquiring the weld pool image IMG represented by a digital signal from the imaging unit 8.

[0182] Thereafter, the control unit 7 may detect the weld pool area MPA in the additive image IMG_C, in which the weld pools MP#1 and MP#2 are reflected. Specifically, as shown on the left side of FIG. 11 , the signal value of the area in the weld pool image IMG where the weld pool MP is reflected differs from the signal value of the area in which the weld pool MP is not reflected. This is because the weld pool MP emits strong light. Therefore, the luminance value of the area in the weld pool image IMG where the weld pool MP is reflected differs from the luminance value of the area in which the weld pool MP is not reflected. Typically, the luminance value of the area in the weld pool image IMG where the weld pool MP is reflected is higher than the luminance value of the area in which the weld pool MP is not reflected. Therefore, as shown on the right side of FIG. 11 , the signal value of the area in the additive image IMG_C where the weld pool MP is reflected differs from the signal value of the area in which the weld pool MP is not reflected. In other words, the signal value of the weld pool area MPA in the additive image IMG_C differs from the signal value of the area other than the weld pool area MPA. Typically, the brightness value of the weld pool region MPA is higher than the brightness value of a region other than the weld pool region MPA. Therefore, the control unit 7 may detect the weld pool region MPA in the added image IMG_C by comparing the signal value (e.g., brightness value) of each pixel of the added image IMG_C with a predetermined signal threshold.

[0183] For example, the control unit 7 may detect pixels in the added image IMG_C that have signal values ​​(e.g., luminance values) greater than a predetermined signal threshold. That is, the control unit 7 may detect pixels in the added image IMG_C whose added signal values ​​(e.g., luminance values) are greater than a predetermined signal threshold. In this case, the control unit 7 may detect an area including the detected pixels as the molten pool area MPA.

[0184] For example, the control unit 7 may set the signal values ​​of pixels in the additive image IMG_C that have signal values ​​(e.g., luminance values) greater than a predetermined signal threshold to a first signal value. On the other hand, the control unit 7 may set the signal values ​​of pixels in the additive image IMG_C that have signal values ​​(e.g., luminance values) less than the predetermined signal threshold to a second signal value (e.g., 0) different from the first signal value. Thereafter, the control unit 7 may detect, as the molten pool area MPA, an area including pixels whose signal values ​​are the first signal value.

[0185] In this case, a signal value of "1" may be used as the first signal value, and a signal value of "0" may be used as the second signal value. That is, the control unit 7 may set the signal value of a pixel in the added image IMG_C that has a signal value greater than a predetermined signal threshold to 1. On the other hand, the control unit 7 may set the signal value of a pixel in the added image IMG_C that has a signal value smaller than the predetermined signal threshold to 0. Thereafter, the control unit 7 may detect an area including pixels with a signal value of 1 as the molten pool area MPA.

[0186] The signal threshold may be set to an appropriate value that allows the weld pool area MPA to be distinguished from an area other than the weld pool area MPA based on the signal value (e.g., brightness value). The signal threshold may be set in advance. The signal threshold may be set as appropriate by the control unit 7. The signal threshold may be set as appropriate by the user of the machining system SYS.

[0187] The weld pool area MPA detected in the additive image IMG_C may be considered to be substantially equivalent to the area through which the weld pools MP#1 and MP#2 moved. In particular, the weld pool area MPA detected in the additive image IMG_C may be considered to be substantially equivalent to the area through which the weld pools MP#1 and MP#2 moved during the period when the at least two weld pool images IMG used to generate the additive image IMG_C were captured. Therefore, the weld pool area MPA may refer to the area through which the weld pools MP#1 and MP#2 moved.

[0188] The molten pool area MPA detected in the additive image IMG_C may be considered to be substantially equivalent to the area where the machining system SYS successively forms the molten pools MP#1 and MP#2 at different positions. Therefore, the molten pool area MPA may mean the area where the machining system SYS successively forms the molten pools MP#1 and MP#2 at different positions.

[0189] The control unit 7 may then generate information about the weld pool region MPA as weld pool image information MPI based on the detection result of the weld pool region MPA. For example, the control unit 7 may generate information about the size of the weld pool region MPA as an example of the information about the weld pool region MPA. As an example, the control unit 7 may calculate the area of ​​the weld pool region MPA and generate information about the calculated area of ​​the weld pool region MPA as information about the size of the weld pool region MPA. In this case, the control unit 7 may calculate the number of pixels constituting the weld pool region MPA as the area of ​​the weld pool region MPA. That is, the control unit 7 may generate information about the size of the weld pool region MPA by calculating the number of pixels having a signal value (e.g., brightness value) greater than a predetermined signal threshold based on the additive image IMG_C.

[0190] However, instead of using multiple weld pool images IMG, the control unit 7 may generate information about the weld pool area MPA using a single weld pool image IMG. Specifically, the control unit 7 may detect the weld pool area MPA in the weld pool image IMG by comparing the signal value (e.g., brightness value) of each pixel in the weld pool image IMG with a predetermined signal threshold. For example, the control unit 7 may detect pixels in the weld pool image IMG that have a signal value (e.g., brightness value) greater than the predetermined signal threshold. In this case, the control unit 7 may detect the area including the detected pixel as the weld pool area MPA. Then, the control unit 7 may generate information about the weld pool area MPA as weld pool image information MPI based on the detection result of the weld pool area MPA.

[0191] Alternatively, when the exposure time of the imaging unit 8 is longer than a certain time, there is a high possibility that a weld pool area MPA similar to the weld pool area MPA reflected in the additive image IMG_C will be reflected in one weld pool image IMG. For example, when the exposure time of the imaging unit 8 is longer than a certain time determined according to the period of the periodic movement of the weld pools MP#1 and MP#2, there is a high possibility that a weld pool area MPA similar to the weld pool area MPA reflected in the additive image IMG_C will be reflected in one weld pool image IMG. As an example, when the exposure time of the imaging unit 8 is longer than one period of the periodic movement of the weld pools MP#1 and MP#2, there is a high possibility that a weld pool area MPA similar to the weld pool area MPA reflected in the additive image IMG_C will be reflected in one weld pool image IMG. For this reason, when the exposure time of the imaging unit 8 is longer than a certain time, the control unit 7 may generate weld pool image information MPI without using multiple weld pool images IMG. Note that this certain time may be the period required for one cycle of the periodic movement of the weld pools MP#1 and MP#2. This certain time may be half the period required for one cycle of the periodic movement of the weld pools MP#1 and MP#2. This certain time may be one-third of the period required for one cycle of the periodic movement of the weld pools MP#1 and MP#2. The control unit 7 may generate the weld pool image information MPI using a single weld pool image IMG that includes the weld pool area MPA.

[0192] The exposure time of the imaging unit 8 may refer to the time during which the imaging element of the imaging unit 8 is exposed to light. For example, if the imaging unit 8 includes a mechanical shutter, the exposure time of the imaging unit 8 may refer to the time during which the mechanical shutter is open. In other words, the exposure time of the imaging unit 8 may refer to the time from when the mechanical shutter is switched to the open state to when the mechanical shutter is switched to the closed state. The open state may refer to the state in which the mechanical shutter is open. The closed state may refer to the state in which the mechanical shutter is closed. Alternatively, if the imaging unit 8 includes an electronic shutter, the exposure time of the imaging unit 8 may refer to the time during which the electronic shutter is on. In other words, the exposure time of the imaging unit 8 may refer to the time from when the electronic shutter is switched to the on state to when the electronic shutter is switched to the off state. The on state may refer to the state in which the electronic shutter is on. The state in which the electronic shutter is on may refer to a state in which each pixel of the image sensor is exposed to light in one image capture and each pixel of the image sensor can accumulate electric charge based on the amount of light.

[0193] Alternatively, if the imaging unit 8 is equipped with a mechanical shutter, the imaging unit 8 may open and close the mechanical shutter multiple times at timing synchronized with the above-mentioned imaging rate. Even in this case, the imaging unit 8 may be considered to be performing multiple exposures. The imaging unit 8 may then read out the charges accumulated in each pixel of the imaging element. Even in this case, there is a high possibility that a single weld pool image IMG generated by the imaging unit 8 will include a weld pool area MPA similar to the weld pool area MPA included in the additive image IMG_C. Therefore, the control unit 7 may generate the weld pool image information MPI using a single weld pool image IMG including the weld pool area MPA.

[0194] Even if the imaging unit 8 is equipped with an electronic shutter, the imaging unit 8 may turn the electronic shutter on and off multiple times in synchronization with the imaging rate. In this case, the imaging unit 8 may be considered to be performing multiple exposures. The imaging unit 8 may then read out the charges accumulated in each pixel of the imaging element. Even in this case, there is a high possibility that a single weld pool image IMG generated by the imaging unit 8 will include a weld pool area MPA similar to the weld pool area MPA captured in the additive image IMG_C. Therefore, the control unit 7 may generate the weld pool image information MPI using a single weld pool image IMG that includes the weld pool area MPA. However, the imaging unit 8 may also read out the charges accumulated in each pixel of the imaging element each time the electronic shutter is turned on and off. In this case, the imaging unit 8 may be considered to be generating multiple weld pool images IMG as time-series data.

[0195] 9, the control unit 7 then controls the machining system SYS based on the molten pool image information MPI generated in step S12 (step S13). For example, as shown in FIG. 12, the control unit 7 controls the machining system SYS based on the molten pool image information MPI so that the size of the molten pool area MPA becomes a predetermined target size TS.

[0196] As an example, the control unit 7 may control the intensity of at least one of the processing light EL#1 emitted by the light source 4#1 and the processing light EL#2 emitted by the light source 4#2 so that the size of the weld pool area MPA becomes a predetermined target size TS. That is, the control unit 7 may perform DC modulation control, which controls the DC component of the intensity of at least one of the processing light EL#1 and EL#2. That is, changing the intensity of the processing light EL#1 changes the size of the weld pool MP#1. For example, the higher the intensity of the processing light EL#1, the greater the amount of the building material M (or the material constituting the building surface MS) melted by the processing light EL#1. Therefore, the higher the intensity of the processing light EL#1, the larger the size of the weld pool MP#1. Similarly, the higher the intensity of the processing light EL#2, the larger the size of the weld pool MP#2. Changing the sizes of the weld pools MP#1 and MP#2 changes the size of the weld pool area MPA reflected in the weld pool image IMG or the additive image IMG_C. Therefore, the control unit 7 can control the size of the molten pool area MPA by controlling the intensity of at least one of the processing lights EL#1 and EL#2.

[0197] As another example, the control unit 7 may control at least one of the galvanometer mirrors 2146 and 2156, which move the weld pool MP#1 and MP#2, respectively, so that the size of the weld pool area MPA becomes a predetermined target size TS. When the range over which the galvanometer mirror 2146 moves the weld pool MP#1 changes, the size of the weld pool area MPA reflected in the weld pool image IMG or the additive image IMG_C changes. Similarly, when the range over which the galvanometer mirror 2156 moves the weld pool MP#2 changes, the size of the weld pool area MPA reflected in the weld pool image IMG or the additive image IMG_C changes. Therefore, the control unit 7 can control the size of the weld pool area MPA by controlling at least one of the galvanometer mirrors 2146 and 2156.

[0198] The operation of controlling the machining system SYS so that the size of the weld pool region MPA becomes the target size TS may include an operation of controlling the machining system SYS so that the difference between the size of the weld pool region MPA and the target size TS becomes smaller. In other words, the operation of controlling the machining system SYS so that the size of the weld pool region MPA becomes the target size TS may include an operation of controlling the machining system SYS so that the size of the weld pool region MPA becomes closer to the target size TS. Furthermore, the operation of controlling the machining system SYS so that the size of the weld pool region MPA becomes the target size TS may include an operation of controlling the machining system SYS so that the difference between the size of the weld pool region MPA and the target size TS becomes zero. In other words, the operation of controlling the machining system SYS so that the size of the weld pool region MPA becomes the target size TS may include an operation of controlling the machining system SYS so that the size of the weld pool region MPA becomes equal to the target size TS. In either case, the control unit 7 may be considered to be performing feedback control of the machining system SYS based on the size of the weld pool region MPA.

[0199] As a result, the size of the weld pool area MPA is maintained at the target size TS. As described above, the weld pool area MPA corresponds to the area through which the weld pools MP#1 and MP#2 move. Therefore, the size of the weld pool area MPA is essentially correlated with the sizes of the machining unit areas BSA#1 and BSA#2 through which the weld pools MP#1 and MP#2 move, respectively. Therefore, when the size of the weld pool area MPA is maintained at the target size TS, the sizes of the machining unit areas BSA#1 and BSA#2 are also maintained at sizes corresponding to the target size TS. As a result, the size (typically, width) of a linear object formed by moving the machining unit areas BSA#1 and BSA#2 on the building surface MS is also maintained at a size corresponding to the target size TS. This is because the size of the linear object is correlated with the sizes of the machining unit areas BSA#1 and BSA#2. Therefore, the machining system SYS can form a linear object having a desired size (typically, a desired width) by performing a weld pool feedback control operation. In other words, by performing the molten pool feedback control operation, the machining system SYS reduces the possibility of erroneously forming a linear object having a size different from the desired size, allowing the machining system SYS to form an object with high forming accuracy.

[0200] In the above description, the control unit 7 generates the molten pool image information MPI that correlates with the sizes of the machining unit areas BSA#1 and BSA#2 by adding together at least two molten pool images IMG. However, the control unit 7 may calculate an index value that correlates with the sizes of the machining unit areas BSA#1 and BSA#2 (i.e., the sizes of the areas through which the molten pools MP#1 and MP#2 move) from at least two molten pool images IMG without adding together at least two molten pool images IMG. In this case, the control unit 7 may control the machining system SYS in step S13 of Fig. 9 so that the calculated index value becomes the above-mentioned target size TS (or a value corresponding to the target size TS).

[0201] As an example, the control unit 7 may calculate the sizes of at least two weld pools MP that appear in at least two weld pool images IMG. For example, the control unit 7 may calculate the size of the weld pool MP that appears in the first weld pool image IMG, and also calculate the sizes of weld pools MP#1 and MP#2 that appear in a second weld pool image IMG that is different from the first weld pool image IMG. The control unit 7 may then add together the calculated sizes of at least two weld pools MP. For example, the control unit 7 may add together the sizes of the weld pools MP#1 and MP#2 that appear in the first weld pool image IMG and the sizes of the weld pools MP#1 and MP#2 that appear in the second weld pool image IMG. In this case, the value obtained by adding together the sizes of the at least two weld pools MP may be used as an index value that correlates with the sizes of the machining unit areas BSA#1 and BSA#2 (i.e., the size of the area through which the weld pools MP#1 and MP#2 move).

[0202] As another example, the control unit 7 may calculate the positions of at least two weld pools MP that appear in at least two weld pool images IMG. For example, the control unit 7 may calculate the positions of weld pools MP#1 and MP#2 that appear in a first weld pool image IMG, and also calculate the positions of weld pools MP#1 and MP#2 that appear in a second weld pool image IMG that is different from the first weld pool image IMG. The control unit 7 may then calculate the sizes of the machining unit areas BSA#1 and BSA#2 (i.e., the sizes of the areas through which weld pools MP#1 and MP#2 move) based on the calculated positions of at least two weld pools MP. For example, as described above, because the target irradiation area EA#1 periodically moves along one direction within the machining unit area BSA#1, the weld pool MP#1 also periodically moves along one direction. In this case, the control unit 7 may calculate the positions of both ends in one direction of the area through which the weld pool MP#1 moves based on the calculated position of the weld pool MP#1. For example, the control unit 7 may calculate the position where the coordinate indicating the position of the molten pool MP#1 is maximum and the position where the coordinate indicating the position of the molten pool MP#1 is minimum as the positions of both ends in one direction of the area through which the molten pool MP#1 moves. Then, the control unit 7 may calculate the distance between the calculated positions of both ends as an index value correlating with the size of the machining unit areas BSA#1 and BSA#2 (i.e., the size of the area through which the molten pools MP#1 and MP#2 move). In this case, the control unit 7 may control the machining system SYS in step S13 of FIG. 9 so that the calculated index value becomes a distance corresponding to the above-mentioned target size TS.

[0203] (2-3) Zone Detection Operation As described above, in the weld pool feedback control operation (particularly, in step S12 of FIG. 9 ), the control unit 7 detects the weld pool area MPA. At this time, the control unit 7 may perform zone detection operation to accurately detect the weld pool area MPA. In other words, the control unit 7 may perform weld pool feedback control operation including zone detection operation, which is an example of an operation to accurately detect the weld pool area MPA.

[0204] The region detection operation is an operation of detecting at least one of a weld pool region MPA and a non-weld pool region NPA in the weld pool image IMG (or the additive image IMG_C). In other words, the region detection operation may be an operation of determining (in other words, distinguishing) whether each region in the weld pool image IMG (or the additive image IMG_C) is a weld pool region MPA. The region detection operation may be an operation of determining (in other words, distinguishing) whether each region in the weld pool image IMG (or the additive image IMG_C) is a non-weld pool region NPA.

[0205] The non-molten pool area NPA is an area in which the weld pools MP#1 and MP#2 are not reflected. The non-molten pool area NPA may also be an area in which light is reflected, but in which the weld pools MP#1 and MP#2 are not reflected. Specifically, the non-molten pool area NPA may be an area in which at least one of emitted light and reflected light other than that of the weld pools MP#1 and MP#2 is reflected. For example, the non-molten pool area NPA may include an area in which emitted light from an object other than the weld pools MP#1 and MP#2 is reflected. The non-molten pool area NPA may also include an area in which reflected light from an object other than the weld pools MP#1 and MP#2 is reflected. In other words, the non-molten pool area NPA may be an area in which noise light, which is light other than the light generated by the weld pools MP#1 and MP#2, is reflected.

[0206] The noise light may include light caused by spatter generated by scattering of molten material in at least one of the weld pools MP#1 and MP#2. For example, the noise light may include at least one of light emitted by the spatter and light reflected by the spatter. In this case, the non-molten pool area NPA may include an area where the spatter is reflected.

[0207] The noise light may include light caused by fumes generated by evaporation of the molten material in at least one of the weld pools MP#1 and MP#2. For example, the noise light may include at least one of light emitted by the fumes and light reflected by the fumes. In this case, the non-molten pool area NPA may include an area where fumes are reflected.

[0208] The noise light may include light generated due to the processing light EL being irradiated onto a film on the surface of the workpiece W or the structure layer SL on which the manufacturing surface MS is formed. In this case, the non-molten pool area NPA may include an area into which light generated due to the processing light EL being irradiated onto a film on the surface of the workpiece W or the structure layer SL is reflected.

[0209] The noise light may include light resulting from the forming material M that has not reached the molten pools MP#1 and MP#2. In particular, the noise light may include light resulting from the forming material M that has been melted by at least one of the processing lights EL#1 and EL#2 but has not reached the molten pools MP#1 and MP#2. For example, the noise light may include at least one of light emitted by the forming material M and light reflected by the forming material M. In particular, the noise light may include at least one of light emitted by the molten forming material M and light reflected by the molten forming material M. In this case, the non-molten pool area NPA may include an area in which the forming material M (in particular, the molten forming material M) is reflected.

[0210] The control unit 7 may add together at least two weld pool images IMG to generate an added image IMG_C, and may perform an area detection operation based on the generated added image IMG_C. In other words, the control unit 7 may detect at least one of the weld pool area MPA and the non-weld pool area NPA based on the added image IMG_C.

[0211] Here, with reference to FIGS. 13 and 14, the technical reasons why at least one of the molten pool area MPA and the non-molten pool area NPA can be detected based on the added image IMG_C will be described.

[0212] Figure 13 shows a weld pool image IMG that includes the weld pool area MPA and the non-molten pool area NPA. That is, Figure 13 shows a weld pool image IMG that includes the weld pool area MPA, which corresponds to the area where weld pools MP#1 and MP#2 are reflected, and the non-molten pool area NPA, which corresponds to the area where noise light different from the light generated by weld pools MP#1 and MP#2 is reflected. Here, the light generated by weld pools MP#1 and MP#2 is reflected in the weld pool area MPA, and the noise light is reflected in the non-molten pool area NPA. In other words, light is reflected in both the weld pool area MPA and the non-molten pool area NPA. Therefore, the difference between the signal values ​​of pixels included in the weld pool area MPA and the signal values ​​of pixels included in the non-molten pool area NPA may not be very large. For example, the difference between the brightness values ​​of pixels included in the weld pool area MPA and the brightness values ​​of pixels included in the non-molten pool area NPA may not be very large. For this reason, it may not be easy to distinguish between the weld pool area MPA and the non-weld pool area NPA within a single weld pool image IMG using the above-mentioned signal threshold. In other words, it may not be easy to distinguish between the weld pool area MPA and the non-weld pool area NPA within a single weld pool image IMG. As a result, the control unit 7 may erroneously detect the non-weld pool area NPA as the weld pool area MPA.

[0213] On the other hand, as described above, the galvanometer mirrors 2146 and 2156 periodically move the weld pools MP#1 and MP#2 within the machining unit areas BSA#1 and BSA#2, which are determined based on the machining head 21. Furthermore, because the imaging unit 8 is attached to the machining head 21, the relative positional relationship between the imaging unit 8 and each of the machining unit areas BSA#1 and BSA#2 is fixed. Therefore, the position of the area in the weld pool image IMG where the weld pools MP#1 and MP#2 move is likely to remain the same over time. As a result, the position where the weld pool area MPA appears in the weld pool image IMG is likely to remain the same over time. In other words, the position of the area where the weld pools MP#1 and MP#2 move is unlikely to change significantly between multiple weld pool images IMG. Therefore, as shown in FIG. 14 , which shows multiple weld pool images IMG as time-series data, the position where the weld pool area MPA appears is unlikely to change significantly between multiple weld pool images IMG.

[0214] On the other hand, the position where noise light that generates the non-molten pool area NPA is generated is not necessarily fixed. Therefore, the position where noise light that generates the non-molten pool area NPA is generated is likely to fluctuate over time. Furthermore, the fluctuation in the position where noise light that generates the non-molten pool area NPA is generated is likely to occur with random probability. The position where noise light that generates the non-molten pool area NPA is generated is likely to fluctuate randomly. Therefore, the position where the non-molten pool area NPA is captured in the weld pool image IMG is likely to fluctuate randomly over time. In other words, as shown in Figure 14, which shows multiple weld pool images IMG as time-series data, the position where the non-molten pool area NPA is captured can change significantly between multiple weld pool images IMG.

[0215] Alternatively, noise light is not always generated. Therefore, there is a possibility that the non-molten pool area NPA will not be captured in the weld pool image IMG in the first place. In other words, as shown in Figure 14, which shows multiple weld pool images IMG as time-series data, the multiple weld pool images IMG may include both weld pool images IMG in which the non-molten pool area NPA is captured and weld pool images IMG in which the non-molten pool area NPA is not captured.

[0216] In this case, as shown in Fig. 15, which shows an added image IMG_C generated by adding together the multiple weld pool images IMG shown in Fig. 14, in the added image IMG_C, the difference between the signal values ​​of the pixels included in the weld pool area MPA and the signal values ​​of the pixels included in the non-molten pool area NPA is likely to be large enough to distinguish between them. Specifically, in the added image IMG_C, the brightness values ​​of the pixels included in the weld pool area MPA are likely to be sufficiently high compared to the brightness values ​​of the pixels included in the non-molten pool area NPA so that the two can be distinguished from each other.

[0217] Therefore, the control unit 7 can detect at least one of the weld pool area MPA and the non-weld pool area NPA based on the signal value (e.g., brightness value) of the added image IMG_C. Specifically, the control unit 7 can detect at least one of the weld pool area MPA and the non-weld pool area NPA by comparing the signal value (e.g., brightness value) of each pixel of the added image IMG_C with a predetermined signal threshold.

[0218] For example, the control unit 7 may detect, as the weld pool area MPA, an area in the added image IMG_C that includes pixels having signal values ​​(e.g., brightness values) greater than a predetermined signal threshold. That is, the control unit 7 may detect, as the weld pool area MPA, an area in the added image IMG_C that includes pixels corresponding to the addition result of signal values ​​(e.g., brightness values) greater than a predetermined signal threshold. The control unit 7 may generate weld pool image information MPI that includes information about the weld pool area MPA based on the detected weld pool area MPA.

[0219] For example, the control unit 7 may detect, as the non-molten pool area NPA, an area in the added image IMG_C that includes pixels having signal values ​​(e.g., brightness values) that are smaller than a predetermined signal threshold. In other words, the control unit 7 may detect, as the non-molten pool area NPA, an area in the added image IMG_C that includes pixels corresponding to the addition result of signal values ​​(e.g., brightness values) that are smaller than a predetermined signal threshold. In this case, the control unit 7 may generate molten pool image information MPI that includes information about the molten pool area MPA without using the detected non-molten pool area NPA.

[0220] However, pixels with too small a signal value (e.g., a brightness value) are unlikely to contain noise light. Therefore, the control unit 7 may detect, as the non-molten pool area NPA, an area in the added image IMG_C that includes pixels having a signal value (e.g., a brightness value) that is smaller than the first signal threshold, which is the above-mentioned predetermined signal threshold, and larger than a second signal threshold that is smaller than the first signal threshold. Note that the second signal threshold is typically larger than 0.

[0221] Furthermore, when a molten pool feedback control operation including an area detection operation is performed, the signal threshold may be set to an appropriate value that allows the molten pool area MPA and the non-molten pool area NPA to be distinguished from the signal value (e.g., brightness value).

[0222] As described above, the machining system SYS can detect at least one of the weld pool area MPA and the non-molten pool area NPA by performing the area detection operation. Therefore, compared to a comparative example machining system that does not perform the area detection operation, the machining system SYS is less likely to erroneously detect the non-molten pool area NPA as the weld pool area MPA. Therefore, the size of the weld pool area MPA is maintained at the target size TS. As a result, the sizes of the machining unit areas BSA#1 and BSA#2 are also maintained at sizes corresponding to the target size TS. Therefore, the machining system SYS can form a linear object having a desired size (typically, a desired width) by performing the weld pool feedback control operation. In other words, the machining system SYS can form objects with high forming accuracy.

[0223] The range over which the galvanometer mirrors 2146 and 2156 move the molten pools MP#1 and MP#2, respectively, can be estimated with a certain degree of accuracy from the drive conditions of the galvanometer mirrors 2146 and 2156. Therefore, the control unit 7 may estimate the range over which the galvanometer mirrors 2146 and 2156 move the molten pools MP#1 and MP#2, respectively, estimate the boundary of the range in which the molten pool area MPA is distributed from the estimation result, and detect the area outside the estimated boundary as the non-molten pool area NPA.

[0224] (2-4) Imaging Condition Changing Operation (2-4-1) Overview of Imaging Condition Changing Operation The machining system SYS may perform the imaging condition changing operation in parallel with or before or after the above-described weld pool feedback control operation under the control of the control unit 7. In other words, the machining system SYS may perform the imaging condition changing operation during at least a part of the period during which the above-described weld pool feedback control operation is being performed. The machining system SYS may perform the imaging condition changing operation before the above-described weld pool feedback control operation is performed. The machining system SYS may perform the imaging condition changing operation after the above-described weld pool feedback control operation is performed. Typically, the control unit 7 may perform the imaging condition changing operation.

[0225] The imaging condition changing operation is an operation of changing (in other words, controlling, adjusting, or setting) the imaging conditions used by the imaging unit 8 to image the molten pools MP#1 and MP#2. In other words, the imaging condition changing operation is an operation of changing the imaging conditions used by the imaging unit 8 to image the molten pools MP#1 and MP#2. The imaging condition changing operation is an operation of changing the imaging conditions set in the imaging unit 8 to image the molten pools MP#1 and MP#2.

[0226] The control unit 7 may change the imaging conditions so that the imaging unit 8 can appropriately capture images of the molten pools MP#1 and MP#2. For example, the control unit 7 may change the imaging conditions so that the imaging unit 8 can generate a molten pool image IMG that enables the above-described molten pool feedback control operation to be appropriately performed. For example, the control unit 7 may change the imaging conditions so that the imaging unit 8 can generate a molten pool image IMG that enables the machining system SYS to realize a state in which it can form a linear object having a desired size (typically, a desired width) through the above-described molten pool feedback control operation.

[0227] In this case, the imaging unit 8 images the molten pools MP#1 and MP#2 based on the imaging conditions changed by the control unit 7. In other words, the control unit 7 controls the imaging unit 8 to image the molten pools MP#1 and MP#2 based on the imaging conditions changed by the control unit 7.

[0228] The imaging conditions may include conditions regarding the imaging timing at which the imaging unit 8 images the molten pools MP#1 and MP#2. In this case, the control unit 7 may change the imaging timing. For example, as shown in FIG. 16( a), the control unit 7 may change the imaging timing so that the imaging timing is earlier than the imaging timing before the change. For example, as shown in FIG. 16( a), the control unit 7 may change the imaging timing so that the imaging timing is later than the imaging timing before the change.

[0229] The condition related to the imaging timing may include the timing when the imaging unit 8 starts imaging the molten pools MP#1 and MP#2, as shown in FIG. 16( a). The condition related to the imaging timing may include the timing when the imaging unit 8 finishes imaging the molten pools MP#1 and MP#2, as shown in FIG. 16( a). The timing when the imaging unit 8 starts imaging the molten pools MP#1 and MP#2 may refer to the timing when the imaging unit 8 switches the state of the mechanical shutter from a closed state to an open state. The timing when the imaging unit 8 starts imaging the molten pools MP#1 and MP#2 may refer to the timing when the imaging unit 8 switches the state of the electronic shutter from an off state to an on state. The timing when the imaging unit 8 finishes imaging the molten pools MP#1 and MP#2 may refer to the timing when the imaging unit 8 switches the state of the mechanical shutter from an open state to a closed state. The timing when the imaging unit 8 starts imaging the molten pools MP#1 and MP#2 may refer to the timing when the imaging unit 8 switches the state of the electronic shutter from an on state to an off state.

[0230] In addition, when the imaging unit 8 can be considered to be performing multiple exposure as described above, the imaging timing shown in Fig. 16(a) may be considered to be the timing for performing each of the multiple exposures in the multiple exposure. In other words, one pulse waveform shown in Fig. 16(a) may be considered to indicate the timing for performing one exposure in the multiple exposure.

[0231] The imaging conditions may include a condition regarding the exposure time for the imaging unit 8 to capture images of the molten pools MP#1 and MP#2. In this case, the control unit 7 may change the exposure time. For example, as shown in FIG. 16( b), the control unit 7 may change the exposure time so that the exposure time becomes shorter than the exposure time before the change. For example, as shown in FIG. 16( b), the control unit 7 may change the exposure time so that the exposure time becomes longer than the exposure time before the change.

[0232] 16B, the exposure time may refer to the time from when the imaging unit 8 starts capturing images of the molten pools MP#1 and MP#2 to when the imaging unit 8 finishes capturing images of the molten pools MP#1 and MP#2.

[0233] Furthermore, if the imaging unit 8 can be considered to be performing multiple exposures as described above, the exposure time shown in Fig. 16(b) may be considered to be the time for performing each of the multiple exposures in the multiple exposures. In other words, one pulse waveform shown in Fig. 16(b) may be considered to indicate the period during which one exposure in the multiple exposures is performed.

[0234] The imaging conditions may include conditions regarding the imaging period or imaging rate at which the imaging unit 8 images the molten pools MP#1 and MP#2. In this case, the control unit 7 may change the imaging period or imaging rate. For example, as shown in FIG. 16( c), the control unit 7 may change the imaging period so that the imaging period is longer than the imaging period before the change. For example, as shown in FIG. 16( c), the control unit 7 may change the imaging period so that the imaging period is shorter than the imaging period before the change. For example, as shown in FIG. 16( c), the control unit 7 may change the imaging rate so that the imaging rate is lower than the imaging rate before the change. For example, as shown in FIG. 16( c), the control unit 7 may change the imaging rate so that the imaging rate is higher than the imaging rate before the change.

[0235] The definitions of the imaging period and imaging rate have already been explained, and therefore detailed explanations thereof will be omitted. In the example shown in Fig. 16(c), the imaging period may mean the time from when the imaging unit 8 starts imaging the molten pools MP#1 and MP#2 until the imaging unit 8 next starts imaging the molten pools MP#1 and MP#2. The imaging rate may mean the number of times the imaging unit 8 starts imaging the molten pools MP#1 and MP#2 per unit time (e.g., per second).

[0236] As described above, the imaging rate may be the reciprocal of the imaging period. In other words, the imaging period may be the reciprocal of the imaging rate. In this case, an operation of changing the imaging rate to lower the imaging rate may be considered equivalent to an operation of changing the imaging period to lengthen the imaging period. An operation of changing the imaging rate to increase the imaging rate may be considered equivalent to an operation of changing the imaging period to shorten the imaging period.

[0237] Note that, if the imaging unit 8 can be considered to be performing multiple exposure as described above, the imaging period shown in Fig. 16(c) may be considered to be the period in which each of the multiple exposures in the multiple exposure is performed. In other words, the interval between two adjacent pulse waveforms shown in Fig. 16(b) may be considered to indicate the period in which one exposure in the multiple exposure is performed. Also, if the imaging unit 8 can be considered to be performing multiple exposure as described above, the imaging rate shown in Fig. 16(c) may be considered to be an index value indicating the number of exposures per unit time in the multiple exposure (this index value may also be referred to as the exposure rate).

[0238] Note that when the imaging conditions are changed, the operation of the imaging unit 8 for generating multiple molten pool images IMG as time-series data also changes. Considering that the imaging unit 8 can be considered to generate multiple molten pool images IMG as time-series data by performing multiple exposure as described above, the operation of changing the imaging conditions can be considered equivalent to the operation of changing the multiple exposure conditions.

[0239] (2-4-2) Changing the Imaging Conditions Based on Machining Conditions The control unit 7 may change the imaging conditions based on the machining conditions of the workpiece W by the machining system SYS. For example, when the machining system SYS machines the workpiece W based on first machining conditions, the control unit 7 may change the imaging conditions so that the imaging unit 8 images the molten pools MP#1 and MP#2 based on the first imaging conditions. For example, when the machining system SYS machines the workpiece W based on second machining conditions different from the first machining conditions, the control unit 7 may change the imaging conditions so that the imaging unit 8 images the molten pools MP#1 and MP#2 based on the second imaging conditions different from the first imaging conditions.

[0240] The control unit 7 may change the imaging conditions so that the imaging unit 8 can properly image the molten pools MP#1 and MP#2 even when the machining conditions are changed. For example, when the machining system SYS machines the workpiece W based on first machining conditions, the control unit 7 may change the imaging conditions to first imaging conditions so that the imaging unit 8 can properly image the molten pools MP#1 and MP#2 formed by the machining system SYS based on the first machining conditions. For example, when the machining system SYS machines the workpiece W based on second machining conditions, the control unit 7 may change the imaging conditions to second imaging conditions so that the imaging unit 8 can properly image the molten pools MP#1 and MP#2 formed by the machining system SYS based on the second machining conditions.

[0241] The control unit 7 may change the imaging conditions based on the machining conditions using an imaging condition table that defines the correspondence between the machining conditions and the imaging conditions. The imaging condition table may be a table that specifies the imaging conditions to be used by the imaging unit 8 when the machining conditions of the workpiece W are certain machining conditions. The imaging condition table may be a table that records information on the imaging conditions to be used by the imaging unit 8 in association with the machining conditions of the workpiece W. The imaging condition table may be stored (in other words, recorded) in the storage device 72. The imaging condition table may be generated in advance by repeatedly performing the above-mentioned molten pool feedback control operation while changing at least one of the machining conditions and the imaging conditions, and by identifying the correspondence between the machining conditions and the imaging conditions that can achieve a state in which the manufacturing accuracy of a linear object formed as a result of the molten pool feedback control operation is desired.

[0242] (2-4-2-1) First Specific Example of Processing Conditions The processing conditions may include light conditions related to at least one of the processing lights EL#1 and EL#2. Since each of the processing lights EL#1 and EL#2 is an example of an energy beam, the light conditions may also be referred to as beam conditions. The light conditions may include intensity conditions related to the intensity of at least one of the processing lights EL#1 and EL#2. In this case, the control unit 7 may change the imaging conditions based on the intensity of at least one of the processing lights EL#1 and EL#2 irradiated onto the workpiece W to process the workpiece W.

[0243] Here, as a first specific example of the operation of changing the imaging conditions, an example of the operation of changing the imaging conditions when the intensity of the processing light EL#k (where k is a variable indicating either 1 or 2) is changed from a first intensity to a second intensity higher than the first intensity will be described. In this case, because the intensity of the processing light EL#k changes, the brightness value (or any signal value) of the pixel in which the weld pool MP#k is reflected in the weld pool image IMG also changes. In this case, the control unit 7 may change the imaging conditions so that the amount of change in the brightness value of the pixel in which the weld pool MP#k is reflected in the weld pool image IMG is kept below a first allowable amount, even when the intensity of the processing light EL#k is changed from the first intensity to the second intensity. That is, the control unit 7 may change the imaging conditions so that the difference between the brightness value of a pixel in which the weld pool MP#k is reflected in the weld pool image IMG generated when the intensity of the processing light EL#k is the first intensity and the brightness value of a pixel in which the weld pool MP#k is reflected in the weld pool image IMG generated when the intensity of the processing light EL#k is the second intensity is equal to or less than a first allowable amount. Typically, the control unit 7 may change the imaging conditions so that the brightness value of a pixel in which the weld pool MP#k is reflected in the weld pool image IMG remains constant even when the intensity of the processing light EL#k is changed from the first intensity to the second intensity. That is, the control unit 7 may change the imaging conditions so that the brightness value of a pixel in which the weld pool MP#k is reflected in the weld pool image IMG generated when the intensity of the processing light EL#k is the first intensity is equal to the brightness value of a pixel in which the weld pool MP#k is reflected in the weld pool image IMG generated when the intensity of the processing light EL#k is the second intensity.

[0244] More specifically, as the intensity of the machining light EL#k increases, the brightness value of the pixels in the weld pool image IMG where the weld pool MP#k is reflected increases. In this case, the control unit 7 may change the imaging conditions so that the brightness value of the pixels in the weld pool image IMG where the weld pool MP#k is reflected decreases compared to when the imaging conditions are not changed. For example, the shorter the exposure time, which is an example of an imaging condition, the lower the brightness value of the pixels in the weld pool image IMG. Therefore, the control unit 7 may change the exposure time to shorten the exposure time. In other words, the control unit 7 may change the exposure time so that the exposure time when the intensity of the machining light EL#k is the second intensity is shorter than the exposure time when the intensity of the machining light EL#k is the first intensity. As a result, the change in the brightness value of the pixels in the weld pool image IMG where the weld pool MP#k is reflected is suppressed to within the first allowable amount. In some cases, the brightness value of the pixels in the weld pool image IMG where the weld pool MP#k is reflected is maintained constant.

[0245] Considering the first specific example of the operation of changing the imaging conditions, the control unit 7 may change the exposure time so that the higher the intensity of the processing light EL#k, the shorter the exposure time becomes. The control unit 7 may change the exposure time so that the lower the intensity of the processing light EL#k, the longer the exposure time becomes.

[0246] Note that the higher the intensity of the processing light EL#k, the higher the density (e.g., power density, essentially fluence) of the processing light EL#k. Therefore, the light conditions may include conditions related to the density of the processing light EL#k. Changing the imaging conditions based on the intensity of the processing light EL#k may be considered equivalent to changing the imaging conditions based on the density of the processing light EL#k. The control unit 7 may change the imaging conditions based on the density of the processing light EL#k, similar to changing the imaging conditions based on the intensity of the processing light EL#k. For example, the control unit 7 may change the exposure time so that the exposure time becomes shorter as the density of the processing light EL#k increases. The control unit 7 may change the exposure time so that the exposure time becomes longer as the density of the processing light EL#k decreases.

[0247] (2-4-2-2) Second Specific Example of Processing Conditions The processing conditions may include movement mode conditions related to the movement mode of at least one of the target irradiation areas EA#1 and EA#2. In this case, the control unit 7 may change the imaging conditions based on the movement mode of at least one of the target irradiation areas EA#1 and EA#2. As mentioned above, the operation of moving each of the target irradiation areas EA#1 and EA#2 may be referred to as a wobbling operation. Therefore, the movement mode conditions related to the movement mode of at least one of the target irradiation areas EA#1 and EA#2 may be referred to as a wobble condition.

[0248] Because the target irradiation areas EA#1 and EA#2 are irradiated with the processing beams EL#1 and EL#2, respectively, the movement mode condition may be considered equivalent to a condition regarding the movement mode of the irradiation position of at least one of the processing beams EL#1 and EL#2. Because molten pools MP#1 and MP#2 are formed by irradiating the target irradiation areas EA#1 and EA#2 with the processing beams EL#1 and EL#2, respectively, the movement mode condition may be considered equivalent to a condition regarding the movement mode of the irradiation position of at least one of the molten pools MP#1 and MP#2. Because the target irradiation areas EA#1 and EA#2 are moved by deflecting the processing beams EL#1 and EL#2, respectively, the movement mode condition may be considered equivalent to a condition regarding the deflection mode of at least one of the processing beams EL#1 and EL#2.

[0249] The movement mode of the target irradiation area EA#k may include the speed of movement of the target irradiation area EA#k. In particular, the movement mode of the target irradiation area EA#k may include the speed of movement of the target irradiation area EA#k on the printing surface MS. The speed of movement of the target irradiation area EA#k may be considered equivalent to the speed of movement of the irradiation position of the processing light EL#k. In particular, the speed of movement of the target irradiation area EA#k may be considered equivalent to the speed of movement of the irradiation position of the processing light EL#k on the printing surface MS. The speed of movement of the target irradiation area EA#k may be considered equivalent to the speed of deflection of the processing light EL#k. The deflection speed of the processing light EL#1 may be considered equivalent to the rotation speed (oscillation speed) of at least one of the X scanning mirror 2146MX and the Y scanning mirror 2146MY provided in the galvanometer mirror 2146 that deflects the processing light EL#1. The deflection speed of processing light EL#2 may be considered to be equivalent to the rotation speed (oscillation speed) of at least one of the X scanning mirror 2156MX and the Y scanning mirror 2156MY provided in the galvanometer mirror 2156 that deflects processing light EL#2.

[0250] The movement pattern of the target irradiation area EA#k may include the period of movement of the target irradiation area EA#k. In particular, the movement pattern of the target irradiation area EA#k may include the period of periodic movement of the target irradiation area EA#k on the printing surface MS. The period of movement of the target irradiation area EA#k may be considered equivalent to the period of movement of the irradiation position of the processing light EL#k. In particular, the period of movement of the target irradiation area EA#k may be considered equivalent to the period of periodic movement of the irradiation position of the processing light EL#k on the printing surface MS. The period of movement of the target irradiation area EA#k may be considered equivalent to the period of deflection of the processing light EL#k. The period of deflection of the processing light EL#1 may be considered equivalent to the rotation period (oscillation period) of at least one of the X scanning mirror 2146MX and the Y scanning mirror 2146MY included in the galvanometer mirror 2146 that deflects the processing light EL#1. The deflection period of processing light EL#2 may be considered to be equivalent to the rotation period (oscillation period) of at least one of the X scanning mirror 2156MX and the Y scanning mirror 2156MY provided in the galvanometer mirror 2156 that deflects processing light EL#1.

[0251] The movement mode of the target irradiation area EA#k may include the stroke of the movement of the target irradiation area EA#k (i.e., stroke amount or stroke width). The stroke of the movement may refer to the amplitude of the reciprocating movement. In particular, the movement mode of the target irradiation area EA#k may include the stroke of the movement of the target irradiation area EA#k on the printing surface MS. Note that the stroke of the movement of the target irradiation area EA#k may be considered equivalent to the stroke of the movement of the irradiation position of the processing light EL#k. In particular, the stroke of the movement of the target irradiation area EA#k may be considered equivalent to the stroke of the movement of the irradiation position of the processing light EL#k on the printing surface MS.

[0252] The movement pattern of the target irradiation area EA#k may include a pattern of the movement trajectory of the target irradiation area EA#k. In particular, the movement pattern of the target irradiation area EA#k may include a pattern of a periodic movement trajectory of the target irradiation area EA#k on the printing surface MS. An example of the pattern of the movement trajectory of the target irradiation area EA#k is a wave-shaped pattern (e.g., a sinusoidal wave shape) shown in FIG. 4B. An example of the pattern of the movement trajectory of the target irradiation area EA#k is a spiral-shaped pattern (e.g., a circular shape with a gradually shifting center position) shown in FIG. 5C. Note that the pattern of the movement trajectory of the target irradiation area EA#k may be considered equivalent to the pattern of the movement trajectory of the irradiation position of the processing light EL#k. In particular, the pattern of the movement trajectory of the target irradiation area EA#k may be considered equivalent to the pattern of the periodic movement trajectory of the irradiation position of the processing light EL#k on the printing surface MS.

[0253] Note that, because the movement mode of the target irradiation area EA#1 is determined by control signals that control the operation modes of the X scanning mirror 2146MX and Y scanning mirror 2146MY as the deflection optical system, the control unit 7 may change the imaging conditions based on control signals that control the X scanning mirror 2146MX and Y scanning mirror 2146MY as the deflection optical system. Similarly, because the movement mode of the target irradiation area EA#2 is determined by control signals that control the operation modes of the X scanning mirror 2156MX and Y scanning mirror 2156MY as the deflection optical system, the control unit 7 may change the imaging conditions based on control signals that control the X scanning mirror 2156MX and Y scanning mirror 2156MY as the deflection optical system.

[0254] Here, as a second specific example of the operation of changing the imaging conditions, an example of the operation of changing the imaging conditions when the movement speed of the target irradiation area EA#k is changed from a first speed to a second speed faster than the first speed will be described. In this case, even when the movement speed of the target irradiation area EA#k is changed from the first speed to the second speed, the control unit 7 may change the imaging conditions so that the change in the number of times the imaging unit 8 images the molten pool MP#k during a unit movement period in which the target irradiation area EA#k moves by a unit movement amount is kept below a second allowable amount. In other words, the control unit 7 may change the imaging conditions so that the difference between the number of times the imaging unit 8 images the molten pool MP#k during a unit movement period when the movement speed of the target irradiation area EA#k is the first speed and the number of times the imaging unit 8 images the molten pool MP#k during a unit movement period when the movement speed of the target irradiation area EA#k is the second speed is below a second allowable amount. Typically, the control unit 7 may change the imaging conditions so that the number of times the imaging unit 8 images the molten pool MP#k during a unit movement period in which the target irradiation area EA#k moves by a unit movement amount remains constant, even when the movement speed of the target irradiation area EA#k is changed from the first speed to the second speed. In other words, the control unit 7 may change the imaging conditions so that the number of times the imaging unit 8 images the molten pool MP#k during a unit movement period when the movement speed of the target irradiation area EA#k is the first speed is the same as the number of times the imaging unit 8 images the molten pool MP#k during a unit movement period when the movement speed of the target irradiation area EA#k is the second speed.

[0255] Note that when the period of movement of the target irradiation area EA#k is changed, the speed of movement of the target irradiation area EA#k changes. Typically, the shorter the period of movement of the target irradiation area EA#k, the faster the speed of movement of the target irradiation area EA#k. Therefore, even when the period of movement of the target irradiation area EA#k is changed from the first period to a second period shorter than the first period, the control unit 7 may change the imaging conditions in the same way as when the speed of movement of the target irradiation area EA#k is changed from the first speed to a second speed faster than the first speed. In other words, even when the period of movement of the target irradiation area EA#k is changed from the first period to the second period, the control unit 7 may change the imaging conditions so that the change in the number of times the imaging unit 8 images the molten pool MP#k during a unit movement period is kept below the second allowable amount. Typically, the control unit 7 may change the imaging conditions so that the number of times the imaging unit 8 images the molten pool MP#k during a unit movement period remains constant, even if the period of movement of the target irradiation area EA#k is changed from the first period to the second period.

[0256] When the imaging period of the imaging unit 8 is fixed, the faster the movement speed of the target irradiation area EA#k, the shorter the unit movement period. Therefore, the faster the movement speed of the target irradiation area EA#k, the fewer the number of times the imaging unit 8 images the molten pool MP#k during a unit movement period. Therefore, the control unit 7 may change the imaging period to shorten the imaging period. That is, the control unit 7 may change the imaging period so that the imaging period when the movement speed of the target irradiation area EA#k is the second speed is shorter than the imaging period when the movement speed of the target irradiation area EA#k is the first speed. The control unit 7 may change the imaging period so that the imaging period when the movement period of the target irradiation area EA#k is the second cycle is shorter than the imaging period when the movement period of the target irradiation area EA#k is the first cycle. As a result, the change in the number of times the imaging unit 8 images the molten pool MP#k during a unit movement period is kept below the second allowable amount. In some cases, the number of times the imaging unit 8 captures images of the molten pool MP#k during a unit movement period is maintained constant.

[0257] As described above, the imaging period is the reciprocal of the imaging rate. Therefore, the control unit 7 may change the imaging rate so that the imaging rate becomes higher. In other words, the control unit 7 may change the imaging rate so that the imaging rate when the speed of movement of the target irradiation area EA#k is the second speed is higher than the imaging rate when the speed of movement of the target irradiation area EA#k is the first speed. The control unit 7 may change the imaging rate so that the imaging rate when the period of movement of the target irradiation area EA#k is the second cycle is higher than the imaging rate when the period of movement of the target irradiation area EA#k is the first cycle.

[0258] Considering a second specific example of the operation of changing such imaging conditions, the control unit 7 may change the imaging period so that the imaging period becomes shorter as the movement speed of the target irradiation area EA#k becomes faster. The control unit 7 may change the imaging period so that the imaging period becomes longer as the movement speed of the target irradiation area EA#k becomes slower. The control unit 7 may change the imaging period so that the imaging period becomes shorter as the movement speed of the target irradiation area EA#k becomes shorter. The control unit 7 may change the imaging period so that the imaging period becomes longer as the movement speed of the target irradiation area EA#k becomes longer. The control unit 7 may change the imaging rate so that the imaging rate becomes higher as the movement speed of the target irradiation area EA#k becomes faster. The control unit 7 may change the imaging rate so that the imaging rate becomes lower as the movement speed of the target irradiation area EA#k becomes slower. The control unit 7 may change the imaging rate so that the imaging rate becomes higher as the movement speed of the target irradiation area EA#k becomes shorter. The control unit 7 may change the imaging rate so that the longer the period of movement of the target irradiation area EA#k, the lower the imaging rate.

[0259] In addition to or instead of changing at least one of the imaging period and the imaging rate, the control unit 7 may change the imaging timing. For example, the control unit 7 may change the imaging timing so that the imaging unit 8 can image the molten pool MP#k at appropriate timing even when the movement speed of the target irradiation area EA#k is changed from the first speed to the second speed. Specifically, the control unit 7 may change the imaging timing so that the amount of change in the position of the molten pool MP#k within the machining unit area BSA#k at the timing when the imaging unit 8 images the molten pool MP#k is kept below a third allowable amount even when the movement speed of the target irradiation area EA#k is changed from the first speed to the second speed. In other words, the control unit 7 may change the imaging timing so that the difference between the position of the molten pool MP#k within the machining unit area BSA#k imaged by the imaging unit 8 when the movement speed of the target irradiation area EA#k is the first speed and the position of the molten pool MP#k within the machining unit area BSA#k imaged by the imaging unit 8 when the movement speed of the target irradiation area EA#k is the second speed is equal to or less than a third allowable amount. Typically, the control unit 7 may change the imaging timing so that the position of the molten pool MP#k within the machining unit area BSA#k does not change when the image of the molten pool MP#k is captured by the imaging unit 8, even when the movement speed of the target irradiation area EA#k is changed from the first speed to the second speed. In other words, the control unit 7 may change the imaging timing so that the position of the molten pool MP#k within the machining unit area BSA#k imaged by the imaging unit 8 when the speed of movement of the target irradiation area EA#k is the first speed is the same as the position of the molten pool MP#k within the machining unit area BSA#k imaged by the imaging unit 8 when the speed of movement of the target irradiation area EA#k is the second speed.

[0260] As described above, by performing the imaging condition change operation, the machining system SYS can appropriately capture images of the molten pools MP#1 and MP#2 using the imaging unit 8. By performing the imaging condition change operation, the machining system SYS can appropriately capture images of the molten pools MP#1 and MP#2 using the imaging unit 8, even if the machining conditions are changed. Therefore, the machining system SYS can appropriately perform the above-mentioned molten pool feedback control operation using the molten pool image IMG generated by the imaging unit 8.

[0261] (2-5) Signal Threshold Changing Operation (2-5-1) Overview of Signal Threshold Changing Operation The machining system SYS may perform the signal threshold changing operation in parallel with or before or after the above-described weld pool feedback control operation under the control of the control unit 7. In other words, the machining system SYS may perform the signal threshold changing operation during at least a part of the period during which the above-described weld pool feedback control operation is being performed. The machining system SYS may perform the signal threshold changing operation before the above-described weld pool feedback control operation is performed. The machining system SYS may perform the signal threshold changing operation after the above-described weld pool feedback control operation is performed. Typically, the control unit 7 may perform the signal threshold changing operation.

[0262] The signal threshold changing operation is an operation of changing (in other words, controlling, adjusting or setting) the signal threshold used to detect the weld pool area MPA. That is, the signal threshold changing operation is an operation of changing the signal threshold used by the control unit 7 to detect the weld pool area MPA.

[0263] The control unit 7 may change the signal threshold so that the control unit 7 can appropriately detect the weld pool area MPA. For example, the control unit 7 may change the signal threshold so that the control unit 7 can detect the weld pool area MPA that can generate appropriate weld pool image information MPI. For example, the control unit 7 may change the signal threshold so that the control unit 7 can appropriately detect the weld pool area MPA that has a size that correlates with the size of the machining unit areas BSA#1 and BSA#2. For example, the control unit 7 may change the signal threshold so that the control unit 7 can appropriately detect the weld pool area MPA that has a size that correlates with the size of the linear object to be formed on the building surface MS. For example, the control unit 7 may change the signal threshold so that the control unit 7 can detect the weld pool area MPA that can appropriately perform the above-described weld pool feedback control operation. For example, the control unit 7 may change the signal threshold so that the control unit 7 can detect a molten pool area MPA that can realize a state in which the processing system SYS can form a linear object having a desired size (typically, a desired width) through the above-mentioned molten pool feedback control operation.

[0264] In this case, the control unit 7 detects the weld pool area MPA using the signal threshold changed by the control unit 7. In other words, the control unit 7 performs the weld pool feedback control operation using the signal threshold changed by the control unit 7.

[0265] (2-5-2) Changing the Signal Threshold Based on Machining Conditions The control unit 7 may change the signal threshold based on the machining conditions of the workpiece W by the machining system SYS. For example, when the machining system SYS machines the workpiece W based on first machining conditions, the control unit 7 may change the signal threshold so that the control unit 7 detects the molten pool area MPA using a first signal threshold. For example, when the machining system SYS machines the workpiece W based on second machining conditions different from the first machining conditions, the control unit 7 may change the signal threshold so that the control unit 7 detects the molten pool area MPA using a second signal threshold different from the first signal threshold.

[0266] The control unit 7 may change the signal threshold so that the control unit 7 can appropriately detect the weld pool area MPA even when the machining conditions are changed. For example, when the machining system SYS machines a workpiece W based on first machining conditions, the control unit 7 may change the signal threshold to a first signal threshold so that the control unit 7 can appropriately detect the weld pool area MPA under the conditions in which the machining system SYS is machining the workpiece W under the first machining conditions. For example, when the machining system SYS machines a workpiece W based on second machining conditions, the control unit 7 may change the signal threshold to a second signal threshold so that the control unit 7 can appropriately detect the weld pool area MPA under the conditions in which the machining system SYS is machining the workpiece W under the second machining conditions.

[0267] The control unit 7 may change the signal threshold based on the machining conditions using a signal threshold table that defines the correspondence between the machining conditions and the signal threshold. The signal threshold table may be a table that specifies the signal threshold to be used by the control unit 7 when the machining conditions for the workpiece W are certain machining conditions. The signal threshold table may be a table that records information about the signal threshold to be used by the control unit 7 in association with the machining conditions for the workpiece W. The signal threshold table may be stored (in other words, recorded) in the storage device 72. The signal threshold table may be generated in advance by repeatedly performing the above-described molten pool feedback control operation while changing at least one of the machining conditions and the signal threshold, and by identifying the correspondence between the machining conditions and the signal threshold that can achieve a state in which the forming accuracy of a linear object formed as a result of the molten pool feedback control operation is desired.

[0268] (2-5-2-1) First Specific Example of Processing Conditions As described above, the processing conditions may include an intensity condition regarding the intensity of at least one of the processing beams EL#1 and EL#2. The control unit 7 may change the signal threshold based on the intensity of at least one of the processing beams EL#1 and EL#2 irradiated onto the workpiece W to process the workpiece W.

[0269] Here, as a first specific example of the operation of changing the signal threshold, an example of the operation of changing the signal threshold when the intensity of the processing light EL#k is changed from a first intensity to a second intensity higher than the first intensity will be described. In this case, because the intensity of the processing light EL#k increases, the brightness value (or any signal value) of the pixel in which the molten pool MP#k is reflected in the molten pool image IMG also increases. In this case, the control unit 7 may change the signal threshold so that the signal threshold increases. In other words, the control unit 7 may change the signal threshold so that the higher the intensity of the processing light EL#k, the higher the signal threshold. The control unit 7 may change the signal threshold so that the lower the intensity of the processing light EL#k, the lower the signal threshold.

[0270] In this case, the control unit 7 can properly detect the area that should be detected as the weld pool area MPA as the weld pool area MPA. Specifically, FIG. 17 shows a histogram of brightness values ​​in the weld pool image IMG when the intensity of the processing light EL#k is a first intensity and a histogram of brightness values ​​in the weld pool image IMG when the intensity of the processing light EL#k is a second intensity. As shown in FIG. 17 , if the signal threshold is not changed when the intensity of the processing light EL#k is changed from the first intensity to a second intensity higher than the first intensity, the brightness values ​​of areas that should not be detected as the weld pool area MPA may be higher than the unchanged signal threshold. Therefore, the control unit 7 may erroneously detect areas that should not be detected as the weld pool area MPA as the weld pool area MPA. On the other hand, as shown in FIG. 17 , if the signal threshold is changed when the intensity of the processing light EL#k is changed from the first intensity to the second intensity, the brightness values ​​of areas that should not be detected as the weld pool area MPA may be lower than the changed signal threshold. Therefore, the control unit 7 is less likely to mistakenly detect an area that should not be detected as the weld pool area MPA as the weld pool area MPA. As a result, the control unit 7 can properly detect an area that should be detected as the weld pool area MPA as the weld pool area MPA. In other words, the control unit 7 can accurately detect the weld pool area MPA.

[0271] Figure 18 also shows a histogram of brightness values ​​in the weld pool image IMG when the intensity of the processing light EL#k is a first intensity and a histogram of brightness values ​​in the weld pool image IMG when the intensity of the processing light EL#k is a second intensity. As shown in Figure 18, the unchanged signal threshold is set to a value that allows for distinguishing between the weld pool area MPA and the non-molten pool area NPA in the weld pool image IMG when the intensity of the processing light EL#k is the first intensity. In this case, when the intensity of the processing light EL#k is changed from the first intensity to the second intensity, the brightness of the area to be detected as the non-molten pool area NPA may increase. This is because the non-molten pool area NPA includes an area where noise light generated by irradiation with the processing light EL is captured, and when the intensity of the processing light EL increases, the intensity of the noise light may also increase. As a result, as shown in Figure 18, if the signal threshold is not changed when the intensity of the processing light EL#k is changed from the first intensity to the second intensity, the brightness of the area to be detected as the non-molten pool area NPA may be higher than the unchanged signal threshold. Therefore, the control unit 7 may erroneously detect an area that should be detected as a non-molten pool area NPA as a weld pool area MPA. On the other hand, as shown in FIG. 18 , if the signal threshold is changed while the intensity of the processing light EL#k is changed from the first intensity to the second intensity, the brightness value of the area that should be detected as a non-molten pool area NPA becomes lower than the changed signal threshold. Therefore, the control unit 7 is less likely to erroneously detect an area that should be detected as a non-molten pool area NPA as a weld pool area MPA. As a result, the control unit 7 can properly detect an area that should be detected as a weld pool area MPA as a weld pool area MPA. In other words, the control unit 7 can accurately detect the weld pool area MPA.

[0272] As described above, the processing conditions may include conditions related to the density of the processing light EL#k. In this case, the operation of changing the signal threshold based on the intensity of the processing light EL#k may be considered equivalent to the operation of changing the signal threshold based on the density of the processing light EL#k. The control unit 7 may change the signal threshold based on the density of the processing light EL#k, similar to the case of changing the signal threshold based on the intensity of the processing light EL#k. For example, the control unit 7 may change the signal threshold so that the higher the density of the processing light EL#k, the larger the signal threshold. The control unit 7 may change the signal threshold so that the lower the density of the processing light EL#k, the smaller the signal threshold.

[0273] (2-5-2-2) Second Specific Example of Processing Conditions As described above, the processing conditions may include a movement mode condition regarding the movement mode of at least one of the target irradiation areas EA#1 and EA#2. The control unit 7 may change the signal threshold based on the movement mode of at least one of the target irradiation areas EA#1 and EA#2.

[0274] As a second specific example of the signal threshold change operation, we will describe an example of the signal threshold change operation when the movement speed of the target irradiation area EA#k is changed from a first speed to a second speed faster than the first speed. In this case, because the movement speed of the target irradiation area EA#k increases, the amount of energy transferred from the processing light EL#k to the build surface MS per unit time decreases. Therefore, the brightness value (or any signal value) of the pixel in which the molten pool MP#k appears in the molten pool image IMG decreases. In this case, the control unit 7 may change the signal threshold so that it decreases as the movement speed of the target irradiation area EA#k increases. The control unit 7 may change the signal threshold so that it decreases as the movement speed of the target irradiation area EA#k decreases.

[0275] In this case, the control unit 7 can properly detect the area that should be detected as the weld pool area MPA as the weld pool area MPA. Specifically, FIG. 19 shows a histogram of brightness values ​​in the weld pool image IMG when the movement speed of the target irradiation area EA#k is a first speed, and a histogram of brightness values ​​in the weld pool image IMG when the movement speed of the target irradiation area EA#k is a second speed. As shown in FIG. 19 , if the signal threshold is not changed when the movement speed of the target irradiation area EA#k is changed from the first speed to a second speed faster than the first speed, the brightness value of the area that should be detected as the weld pool area MPA may be lower than the unchanged signal threshold. Therefore, the control unit 7 may not detect the area that should be detected as the weld pool area MPA as the weld pool area MPA. On the other hand, if the signal threshold is changed when the movement speed of the target irradiation area EA#k is changed from the first speed to the second speed, the brightness value of the area that should be detected as the weld pool area MPA may be higher than the changed signal threshold. Therefore, the control unit 7 can appropriately detect the area that should be detected as the weld pool area MPA as the weld pool area MPA. In other words, the control unit 7 can accurately detect the weld pool area MPA.

[0276] Figure 20 also shows a histogram of brightness values ​​in the weld pool image IMG when the target irradiation area EA#k moves at a first speed and a histogram of brightness values ​​in the weld pool image IMG when the target irradiation area EA#k moves at a second speed. As shown in Figure 20, the unchanged signal threshold is set to a value that allows the weld pool area MPA and the non-molten pool area NPA to be distinguished from each other in the weld pool image IMG when the target irradiation area EA#k moves at the first speed. In this case, when the movement speed of the target irradiation area EA#k is changed from the first speed to the second speed, the brightness of the area that should be detected as the weld pool area MPA decreases. As a result, the brightness value of the area that should be detected as the weld pool area MPA may be lower than the unchanged signal threshold. Therefore, if the signal threshold is not changed when the movement speed of the target irradiation area EA#k is changed from the first speed to the second speed, the control unit 7 may erroneously detect the area that should be detected as the weld pool area MPA as the non-molten pool area NPA. On the other hand, when the signal threshold is changed under the condition that the speed of movement of the target irradiation area EA#k is changed from the first speed to the second speed, the brightness value of the area to be detected as the weld pool area MPA becomes higher than the changed signal threshold. Therefore, the control unit 7 can appropriately detect the area to be detected as the weld pool area MPA as the weld pool area MPA. In other words, the control unit 7 can accurately detect the weld pool area MPA.

[0277] As described above, when the period of movement of the target irradiation area EA#k is changed, the speed of movement of the target irradiation area EA#k changes. Therefore, even when the period of movement of the target irradiation area EA#k is changed from the first period to the second period shorter than the first period, the control unit 7 may change the signal threshold in the same way as when the speed of movement of the target irradiation area EA#k is changed from the first speed to the second speed faster than the first speed. In other words, the control unit 7 may change the signal threshold so that the shorter the period of movement of the target irradiation area EA#k, the smaller the signal threshold. The control unit 7 may change the signal threshold so that the longer the period of movement of the target irradiation area EA#k, the larger the signal threshold.

[0278] As described above, the machining system SYS can appropriately detect the weld pool area MPA by performing the signal threshold value changing operation. By performing the signal threshold value changing operation, the machining system SYS can appropriately (e.g., accurately) detect the weld pool area MPA using the control unit 7 even when the machining conditions are changed. Therefore, the machining system SYS can appropriately perform the above-mentioned weld pool feedback control operation using the weld pool area MPA detected by the control unit 7.

[0279] (2-6) Operation for Changing the Number of Added Frames (2-6-1) Overview of the Operation for Changing the Number of Added Frames As described above, in the weld pool feedback control operation, the machining system SYS generates an added image IMG_C by adding together multiple weld pool images IMG in order to detect the weld pool area MPA. In this case, the machining system SYS may perform the operation for changing the number of added frames in parallel with or before or after the weld pool feedback control operation under the control of the control unit 7. In other words, the machining system SYS may perform the operation for changing the number of added frames during at least a portion of the period during which the weld pool feedback control operation is being performed. The machining system SYS may perform the operation for changing the number of added frames before the weld pool feedback control operation is performed. The machining system SYS may perform the operation for changing the number of added frames after the weld pool feedback control operation is performed. Typically, the control unit 7 may perform the operation for changing the number of added frames.

[0280] The operation of changing the number of added frames is an operation of changing (in other words, controlling, adjusting, or setting) the number of weld pool images IMG to be added to generate the added image IMG_C. In other words, the operation of changing the number of added frames is an operation by which the control unit 7 changes the number of weld pool images IMG to be added to generate the added image IMG_C. In the following description, the number of weld pool images IMG to be added to generate the added image IMG_C will be referred to as the "number of added frames."

[0281] The control unit 7 may change the number of added frames so that the control unit 7 can appropriately detect the weld pool area MPA. For example, the control unit 7 may change the number of added frames so that the control unit 7 can detect the weld pool area MPA that can generate appropriate weld pool image information MPI. For example, the control unit 7 may change the number of added frames so that the control unit 7 can appropriately detect the weld pool area MPA that has a size that correlates with the size of the machining unit areas BSA#1 and BSA#2. For example, the control unit 7 may change the number of added frames so that the control unit 7 can appropriately detect the weld pool area MPA that has a size that correlates with the size of the linear object to be formed on the building surface MS. For example, the control unit 7 may change the number of added frames so that the control unit 7 can detect the weld pool area MPA that can appropriately perform the above-described weld pool feedback control operation. For example, the control unit 7 may change the number of added frames so that the control unit 7 can detect a molten pool area MPA that can realize a state in which the machining system SYS can form a linear object having a desired size (typically, a desired width) through the above-mentioned molten pool feedback control operation.

[0282] In this case, the control unit 7 generates the added image IMG_C using the number of added frames changed by the control unit 7. In other words, the control unit 7 generates the added image IMG_C by adding together the same number of molten pool images IMG as the number of added frames changed by the control unit 7.

[0283] Note that changing the number of added frames changes the operation of the imaging unit 8 for generating multiple weld pool images IMG as time-series data. Considering that the imaging unit 8 may be considered to generate multiple weld pool images IMG as time-series data by performing multiple exposures as described above, changing the number of added frames may be considered equivalent to changing the conditions for multiple exposure. Specifically, the number of added frames may be considered equivalent to the number of exposures required to generate one weld pool image IMG by multiple exposure. In this case, changing the number of added frames may be considered equivalent to changing the number of exposures required to generate one weld pool image IMG by multiple exposure.

[0284] (2-6-2) Changing the Number of Added Frames Based on Machining Conditions The control unit 7 may change the number of added frames based on the machining conditions of the workpiece W by the machining system SYS. For example, when the machining system SYS machines the workpiece W based on first machining conditions, the control unit 7 may change the number of added frames so that the control unit 7 generates the added image IMG_C by adding together the same number of molten pool images IMG as the first number of frames. For example, when the machining system SYS machines the workpiece W based on second machining conditions different from the first machining conditions, the control unit 7 may change the number of added frames so that the control unit 7 generates the added image IMG_C by adding together the same number of molten pool images IMG as the second number of frames different from the first number of frames.

[0285] The control unit 7 may change the number of added frames so that the control unit 7 can appropriately detect the weld pool area MPA even when the machining conditions are changed. For example, when the machining system SYS machines the workpiece W based on first machining conditions, the control unit 7 may change the number of added frames to the first number of frames so that the control unit 7 can appropriately detect the weld pool area MPA under the conditions in which the machining system SYS is machining the workpiece W under the first machining conditions. For example, when the machining system SYS machines the workpiece W based on second machining conditions, the control unit 7 may change the number of added frames to the second number of frames so that the control unit 7 can appropriately detect the weld pool area MPA under the conditions in which the machining system SYS is machining the workpiece W under the second machining conditions.

[0286] The control unit 7 may change the number of added frames based on the machining conditions using a number of added frames table that defines the correspondence between the machining conditions and the number of added frames. The number of added frames table may be a table that specifies the number of added frames that the control unit 7 should use when the machining conditions for the workpiece W are certain. The number of added frames table may be a table that records information regarding the number of added frames that the control unit 7 should use in association with the machining conditions for the workpiece W. The number of added frames table may be stored (in other words, recorded) in the storage device 72. The number of added frames table may be generated in advance by repeatedly performing the above-described molten pool feedback control operation while changing at least one of the machining conditions and the number of added frames, and by identifying the correspondence between the machining conditions and the number of added frames that can achieve a state in which the manufacturing accuracy of a linear object formed as a result of the molten pool feedback control operation is desired.

[0287] (2-6-2-1) First Specific Example of Processing Conditions As described above, the processing conditions may include an intensity condition regarding the intensity of at least one of the processing beams EL#1 and EL#2. The control unit 7 may change the number of added frames based on the intensity of at least one of the processing beams EL#1 and EL#2 irradiated onto the workpiece W to process the workpiece W.

[0288] Here, as a first specific example of the operation of changing the number of added frames, an example of the operation of changing the number of added frames when the intensity of the processing light EL#k is changed from a first intensity to a second intensity higher than the first intensity will be described. In this case, because the intensity of the processing light EL#k increases, the brightness value (or any signal value) of the pixel in which the molten pool MP#k is reflected in the molten pool image IMG also increases. In this case, the control unit 7 may change the number of added frames so that the number of added frames decreases as the intensity of the processing light EL#k increases. The control unit 7 may change the number of added frames so that the number of added frames increases as the intensity of the processing light EL#k decreases.

[0289] In this case, the control unit 7 can appropriately detect the area that should be detected as the weld pool area MPA as the weld pool area MPA. Specifically, Fig. 21(a) shows a histogram of brightness values ​​in the weld pool image IMG when the intensity of the processing light EL#k is the first intensity and the number of added frames is the first number of frames FN11. Fig. 21(b) shows a histogram of brightness values ​​in the weld pool image IMG when the intensity of the processing light EL#k is the second intensity and the number of added frames remains the first number of frames FN11. Fig. 21(c) shows a histogram of brightness values ​​in the weld pool image IMG when the intensity of the processing light EL#k is the second intensity and the number of added frames is changed from the first number of frames FN11 to a second number of frames FN12, which is smaller than the first number of frames FN11. As shown in FIG. 21( b), if the number of added frames is not changed when the intensity of the machining light EL#k is changed from the first intensity to a second intensity higher than the first intensity, the brightness value of an area that should not be detected as the weld pool area MPA may become higher than the signal threshold. Therefore, the control unit 7 may erroneously detect an area that should not be detected as the weld pool area MPA as the weld pool area MPA. On the other hand, if the number of added frames is decreased when the intensity of the machining light EL#k is changed from the first intensity to the second intensity, the brightness value of each pixel in the added image IMG_C decreases. As a result, as shown in FIG. 21( c), the brightness value of an area that should not be detected as the weld pool area MPA becomes lower than the signal threshold. Therefore, the control unit 7 is less likely to erroneously detect an area that should not be detected as the weld pool area MPA as the weld pool area MPA. As a result, the control unit 7 can properly detect an area that should be detected as the weld pool area MPA as the weld pool area MPA. In other words, the control unit 7 can detect the molten pool area MPA with high accuracy.

[0290] Similarly, Figure 22(a) shows a histogram of brightness values ​​in the weld pool image IMG when the intensity of the processing light EL#k is the first intensity and the number of added frames is the first number of frames FN21. Figure 22(b) shows a histogram of brightness values ​​in the weld pool image IMG when the intensity of the processing light EL#k is the second intensity and the number of added frames remains the first number of frames FN21. Figure 22(c) shows a histogram of brightness values ​​in the weld pool image IMG when the intensity of the processing light EL#k is the second intensity and the number of added frames is changed from the first number of frames FN21 to a second number of frames FN22, which is smaller than the first number of frames FN21. As shown in Figure 22(a), the signal threshold is set to a value that allows the weld pool area MPA and the non-weld pool area NPA to be distinguished in the weld pool image IMG when the intensity of the processing light EL#k is the first intensity. As described above, when the intensity of the processing light EL#k is changed from the first intensity to the second intensity, the brightness of the area to be detected as the non-molten pool area NPA may increase. As a result, as shown in FIG. 22( b), if the number of added frames is not changed when the intensity of the processing light EL#k is changed from the first intensity to the second intensity, the brightness value of the area to be detected as the non-molten pool area NPA may be higher than the signal threshold. Therefore, the control unit 7 may erroneously detect an area to be detected as the non-molten pool area NPA as the weld pool area MPA. On the other hand, if the number of added frames is decreased when the intensity of the processing light EL#k is changed from the first intensity to the second intensity, the brightness value of each pixel in the added image IMG_C decreases. As a result, as shown in FIG. 22( c), the brightness value of the area to be detected as the non-molten pool area NPA may be lower than the signal threshold. Therefore, the control unit 7 is less likely to erroneously detect an area to be detected as the non-molten pool area NPA as the weld pool area MPA. As a result, the control unit 7 can appropriately detect the area that should be detected as the weld pool area MPA as the weld pool area MPA. In other words, the control unit 7 can accurately detect the weld pool area MPA.

[0291] As described above, the processing conditions may include conditions related to the density of the processing light EL#k. In this case, changing the number of added frames based on the intensity of the processing light EL#k may be considered equivalent to changing the number of added frames based on the density of the processing light EL#k. The control unit 7 may change the number of added frames based on the density of the processing light EL#k, just as it changes the number of added frames based on the intensity of the processing light EL#k. For example, the control unit 7 may change the number of added frames so that the number of added frames decreases as the density of the processing light EL#k increases. The control unit 7 may change the number of added frames so that the number of added frames increases as the density of the processing light EL#k decreases.

[0292] (2-6-2-2) Second Specific Example of Processing Conditions As described above, the processing conditions may include a movement mode condition regarding the movement mode of at least one of the target irradiation areas EA#1 and EA#2. The control unit 7 may change the number of added frames based on the movement mode of at least one of the target irradiation areas EA#1 and EA#2.

[0293] As a second specific example of the operation for changing the number of added frames, we will now describe an example of the operation for changing the number of added frames when the movement speed of the target irradiation area EA#k is changed from a first speed to a second speed faster than the first speed. In this case, because the movement speed of the target irradiation area EA#k increases, the amount of energy transferred from the processing light EL#k to the printing surface MS per unit time decreases. Therefore, the brightness value (or any signal value) of the pixel in which the molten pool MP#k appears in the molten pool image IMG decreases. In this case, the control unit 7 may change the number of added frames so that the number of added frames increases as the movement speed of the target irradiation area EA#k increases. The control unit 7 may change the number of added frames so that the number of added frames decreases as the movement speed of the target irradiation area EA#k decreases.

[0294] In this case, the control unit 7 can appropriately detect the area that should be detected as the weld pool area MPA as the weld pool area MPA. Specifically, Fig. 23(a) shows a histogram of brightness values ​​in the weld pool image IMG when the movement speed of the target irradiation area EA#k is a first speed and the number of added frames is a first number of frames FN31. Fig. 23(b) shows a histogram of brightness values ​​in the weld pool image IMG when the movement speed of the target irradiation area EA#k is a second speed and the number of added frames remains the first number of frames FN31. Fig. 23(c) shows a histogram of brightness values ​​in the weld pool image IMG when the movement speed of the target irradiation area EA#k is a second speed and the number of added frames is changed from the first number of frames FN31 to a second number of frames FN32, which is greater than the first number of frames FN31. As shown in FIG. 23( b), if the number of added frames is not changed when the movement speed of the target irradiation area EA#k is changed from the first speed to a second speed faster than the first speed, the brightness value of the area to be detected as the weld pool area MPA may fall below the signal threshold. Therefore, the control unit 7 may not detect the area to be detected as the weld pool area MPA as the weld pool area MPA. On the other hand, if the number of added frames is increased when the movement speed of the target irradiation area EA#k is changed from the first speed to the second speed, the brightness value of each pixel in the added image IMG_C increases. As a result, as shown in FIG. 23( c), the brightness value of the area to be detected as the weld pool area MPA becomes higher than the signal threshold. Therefore, the control unit 7 can properly detect the area to be detected as the weld pool area MPA as the weld pool area MPA. In other words, the control unit 7 can accurately detect the weld pool area MPA.

[0295] Similarly, Figure 24(a) shows a histogram of brightness values ​​in the weld pool image IMG when the target irradiation area EA#k moves at a first speed and the number of added frames is a first number FN41. Figure 24(b) shows a histogram of brightness values ​​in the weld pool image IMG when the target irradiation area EA#k moves at a second speed and the number of added frames remains the first number FN41. Figure 24(c) shows a histogram of brightness values ​​in the weld pool image IMG when the target irradiation area EA#k moves at a second speed and the number of added frames is changed from the first number FN41 to a second number FN42, which is greater than the first number FN41. As shown in Figure 24(a), the signal threshold is set to a value that allows the weld pool area MPA and the non-weld pool area NPA to be distinguished from each other in the weld pool image IMG when the target irradiation area EA#k moves at the first speed. In this case, when the movement speed of the target irradiation area EA#k is changed from the first speed to the second speed, the brightness of the area to be detected as the weld pool area MPA decreases. As a result, if the number of added frames is not changed when the movement speed of the target irradiation area EA#k is changed from the first speed to the second speed, the brightness value of the area to be detected as the weld pool area MPA may be lower than the signal threshold, as shown in FIG. 24(b). Therefore, the control unit 7 may erroneously detect the area to be detected as the weld pool area MPA as a non-weld pool area NPA. On the other hand, if the number of added frames is increased when the movement speed of the target irradiation area EA#k is changed from the first speed to the second speed, the brightness value of each pixel in the added image IMG_C increases. As a result, as shown in FIG. 24(c), the brightness value of the area to be detected as the weld pool area MPA becomes higher than the signal threshold. Therefore, the control unit 7 can properly detect the area to be detected as the weld pool area MPA as the weld pool area MPA. In other words, the control unit 7 can detect the molten pool area MPA with high accuracy.

[0296] As described above, when the period of movement of the target irradiation area EA#k is changed, the speed of movement of the target irradiation area EA#k changes. Even when the period of movement of the target irradiation area EA#k is changed from a first period to a second period shorter than the first period, the control unit 7 may change the number of added frames in the same way as when the speed of movement of the target irradiation area EA#k is changed from the first speed to a second speed faster than the first speed. In other words, the control unit 7 may change the number of added frames so that the number of added frames increases as the period of movement of the target irradiation area EA#k becomes shorter. The control unit 7 may change the number of added frames so that the number of added frames decreases as the period of movement of the target irradiation area EA#k becomes longer.

[0297] As described above, the machining system SYS can appropriately detect the weld pool area MPA by changing the number of added frames. By changing the number of added frames, the machining system SYS can appropriately (e.g., accurately) detect the weld pool area MPA using the control unit 7 even when the machining conditions are changed. Therefore, the machining system SYS can appropriately perform the above-mentioned weld pool feedback control operation using the weld pool area MPA detected by the control unit 7.

[0298] The control unit 7 may change the number of added frames based on the exposure time of the imaging unit 8. For example, when the exposure time is changed from a first time to a second time, which is shorter than the first time, the brightness value (or any signal value) of the pixel in which the weld pool MP#k is reflected in the weld pool image IMG decreases. In other words, when the exposure time is shortened, the brightness value (or any signal value) of the pixel in which the weld pool MP#k is reflected in the weld pool image IMG decreases, just as when the movement speed of the target irradiation area EA#k increases. Therefore, the control unit 7 may change the number of added frames based on the exposure time, just as when the number of added frames is changed based on the movement speed of the target irradiation area EA#k. In other words, the control unit 7 may change the number of added frames so that the shorter the exposure time, the larger the number of added frames. The control unit 7 may change the number of added frames so that the longer the exposure time, the smaller the number of added frames.

[0299] (2-7) Target Size Changing Operation (2-7-1) Overview of the Target Size Changing Operation As described above, in step S13 of FIG. 9, the control unit 7 controls the machining system SYS so that the size of the weld pool area MPA becomes the target size TS. In this case, under the control of the control unit 7, the machining system SYS may perform the target size changing operation in parallel with or before or after the above-mentioned weld pool feedback control operation. In other words, the machining system SYS may perform the target size changing operation during at least a portion of the period during which the above-mentioned weld pool feedback control operation is being performed. The machining system SYS may perform the target size changing operation before the above-mentioned weld pool feedback control operation is performed. The machining system SYS may perform the target size changing operation after the above-mentioned weld pool feedback control operation is performed. Typically, the control unit 7 may perform the target size changing operation.

[0300] The target size change operation is an operation of changing (in other words, controlling, adjusting, or setting) the target size TS. That is, the target size change operation is an operation of changing the target size TS used by the control unit 7 to control the machining system SYS.

[0301] In this case, the control unit 7 controls the machining system SYS so that the size of the weld pool area MPA becomes the target size TS changed by the control unit 7. Specifically, as shown in Figure 25, which is a timing chart showing the relationship between the size of the weld pool area and the target size TS, before the target size TS is changed, the control unit 7 controls the machining system SYS so that the size of the weld pool area MPA becomes the target size TS before the change. On the other hand, after the target size TS is changed, the control unit 7 controls the machining system SYS so that the size of the weld pool area MPA becomes the changed target size TS.

[0302] The control unit 7 may change the target size TS so that the machining system SYS can manufacture a linear object having a desired size (typically, a desired width) through the above-described molten pool feedback control operation. As a result, the machining system SYS can manufacture a linear object having a desired size (typically, a desired width). In other words, the machining system SYS can manufacture an object with high manufacturing accuracy.

[0303] (2-7-2) Changing the Target Size TS Based on Machining Conditions The control unit 7 may change the target size TS based on the machining conditions of the workpiece W by the machining system SYS. For example, when the machining system SYS machines the workpiece W based on first machining conditions, the control unit 7 may change the target size TS so that the control unit 7 uses a first size as the target size TS. For example, when the machining system SYS machines the workpiece W based on second machining conditions different from the first machining conditions, the control unit 7 may change the target size TS so that the control unit 7 uses a second size different from the first size as the target size TS.

[0304] The control unit 7 may change the target size TS so that the machining system SYS can form a linear object having a desired size (typically, a desired width) even when the machining conditions are changed. For example, when the machining system SYS machines a workpiece W based on first machining conditions, the control unit 7 may change the target size TS to a first size so that the machining system SYS can form a linear object having a desired size according to the first machining conditions. For example, when the machining system SYS machines a workpiece W based on second machining conditions, the control unit 7 may change the target size TS to a second size so that the machining system SYS can form a linear object having a desired size according to the second machining conditions.

[0305] The control unit 7 may change the target size TS so that a difference between the size (e.g., width) of a linear object formed when the machining system SYS processes the workpiece W based on the first machining conditions and the size (e.g., width) of a linear object formed when the machining system SYS processes the workpiece W based on the second machining conditions is kept equal to or less than a predetermined fourth allowable amount. Typically, the control unit 7 may change the target size TS so that the size (e.g., width) of a linear object formed when the machining system SYS processes the workpiece W based on the first machining conditions is the same as the size (e.g., width) of a linear object formed when the machining system SYS processes the workpiece W based on the second machining conditions. Alternatively, the control unit 7 may change the target size TS so that the difference between the size (e.g., width) of the linear object formed when the processing system SYS processes the workpiece W based on the first processing conditions and the size (e.g., width) of the linear object formed when the processing system SYS processes the workpiece W based on the second processing conditions becomes a predetermined target difference amount.

[0306] The control unit 7 may change the target size TS based on the machining conditions using a target size table that defines the correspondence between the machining conditions and the target size TS. The target size table may be a table that specifies the target size TS to be used by the control unit 7 when the machining conditions for the workpiece W are certain. The target size table may be a table that records information about the target size TS to be used by the control unit 7 in association with the machining conditions for the workpiece W. The target size table may be stored (in other words, recorded) in the storage device 72. The target size table may be generated in advance by repeatedly performing the above-described molten pool feedback control operation while changing at least one of the machining conditions and the target size TS, and by identifying the correspondence between the machining conditions and the target size TS that can achieve a state in which the manufacturing accuracy of a linear object formed as a result of the molten pool feedback control operation is desired.

[0307] (2-7-2-1) First Specific Example of Processing Conditions As described above, the processing conditions may include an intensity condition regarding the intensity of at least one of the processing beams EL#1 and EL#2. The control unit 7 may change the target size TS based on the intensity of at least one of the processing beams EL#1 and EL#2 irradiated onto the workpiece W to process the workpiece W.

[0308] As a first specific example of the operation of changing the target size TS, we will describe an example of the operation of changing the target size TS when the intensity of the processing light EL#k is changed from a first intensity to a second intensity higher than the first intensity. In this case, because the intensity of the processing light EL#k increases, the brightness value (or any signal value) of the pixel in which the weld pool MP#k appears in the weld pool image IMG also increases. Furthermore, due to the increase in the intensity of the processing light EL#k, the number of pixels having a signal value (e.g., brightness value) greater than the signal threshold may increase, even though the area where the weld pools MP#1 and MP#2 formed on the build surface MS move remains unchanged. As a result, the size of the weld pool area MPA calculated in the weld pool feedback control operation may increase, even though the area where the weld pools MP#1 and MP#2 formed on the build surface MS move remains unchanged. In other words, the size of the weld pool area MPA calculated when the intensity of the processing light EL is the second intensity may be larger than the size of the weld pool area MPA calculated when the intensity of the processing light EL is the first intensity.

[0309] Under these circumstances, if the intensity of the processing light EL#k is changed from the first intensity to the second intensity without changing the target size TS, the size of the weld pool area MPA, which matched the target size TS when the intensity of the processing light EL#k was the first intensity, will become larger than the target size TS. In other words, even though the size of the area where the weld pool MP#k actually moves on the build surface MS remains unchanged with the change in the intensity of the processing light EL#k, the size of the weld pool area MPA calculated in the weld pool feedback control operation will increase. For this reason, the control unit 7 controls the processing system SYS to reduce the size of the weld pool area MPA. As a result, the area where the weld pool MP#k actually moves on the build surface MS when the intensity of the processing light EL#k is the second intensity may be smaller than the area where the weld pool MP#k actually moves on the build surface MS when the intensity of the processing light EL#k is the first intensity. That is, the size of the processing unit area BSA#k where the molten pool MP#k is formed when the intensity of the processing light EL#k is the second intensity may be smaller than the size of the processing unit area BSA#k where the molten pool MP#k is formed when the intensity of the processing light EL#k is the first intensity. As a result, the size of the linear object formed when the intensity of the processing light EL#k is the second intensity may be smaller than the size of the linear object formed when the intensity of the processing light EL#k is the first intensity.

[0310] Therefore, the control unit 7 may change the target size TS so that the target size TS becomes larger when the intensity of the processing light EL#k is changed from a first intensity to a second intensity higher than the first intensity. In other words, the control unit 7 may change the target size TS so that the target size TS becomes larger as the intensity of the processing light EL#k becomes higher. The control unit 7 may change the target size TS so that the target size TS becomes smaller as the intensity of the processing light EL#k becomes lower.

[0311] As a result, even if the intensity of the processing light EL#k changes, the size of the processing unit area BSA#k in which the molten pool MP#k is formed does not change unintentionally. As a result, the size (typically, width) of the linear object formed by moving the processing unit areas BSA#1 and BSA#2 on the printing surface MS does not change unintentionally. Therefore, the processing system SYS can form a linear object having a desired size (typically, a desired width) even if the intensity of the processing light EL#k changes. Therefore, the processing system SYS can form an object with high printing accuracy.

[0312] As described above, the processing conditions may include conditions related to the density of the processing light EL#k. In this case, changing the target size TS based on the intensity of the processing light EL#k may be considered equivalent to changing the target size TS based on the density of the processing light EL#k. The control unit 7 may change the target size TS based on the density of the processing light EL#k, similar to changing the target size TS based on the intensity of the processing light EL#k. For example, the control unit 7 may change the target size TS so that the target size TS becomes smaller as the density of the processing light EL#k increases. The control unit 7 may change the target size TS so that the target size TS becomes larger as the density of the processing light EL#k decreases.

[0313] (2-7-2-2) Second Specific Example of Processing Conditions As described above, the processing conditions may include a movement mode condition regarding the movement mode of at least one of the target irradiation areas EA#1 and EA#2. The control unit 7 may change the target size TS based on the movement mode of at least one of the target irradiation areas EA#1 and EA#2.

[0314] For example, the control unit 7 may change the target size TS so that a difference between the size (e.g., width) of a linear object to be formed when the target irradiation area EA#k moves in a first movement mode and the size (e.g., width) of a linear object to be formed when the target irradiation area EA#k moves in a second movement mode different from the first movement mode is kept equal to or less than a predetermined fourth allowable amount. Typically, the control unit 7 may change the target size TS so that the size (e.g., width) of a linear object to be formed when the target irradiation area EA#k moves in the first movement mode is the same as the size (e.g., width) of a linear object to be formed when the target irradiation area EA#k moves in the second movement mode. Alternatively, the control unit 7 may change the target size TS so that the difference between the size (e.g., width) of the linear object formed when the target irradiation area EA#k moves in a first movement mode and the size (e.g., width) of the linear object formed when the target irradiation area EA#k moves in a second movement mode becomes a predetermined target difference amount.

[0315] As an example, as described above, the movement manner of the target irradiation area EA#k may include a stroke of the movement of the target irradiation area EA#k. The larger the stroke of the movement of the target irradiation area EA#k, the larger the size (e.g., width) of the linear object. In this case, the control unit 7 may change the target size TS so that the target size TS increases as the stroke increases. The control unit 7 may change the target size TS so that the target size TS decreases as the stroke decreases. As a result, the machining system SYS can form a linear object having a size corresponding to the stroke.

[0316] As another example, as described above, the movement mode of the target irradiation area EA#k may include the pattern of the movement trajectory of the target irradiation area EA#k. In this case, the control unit 7 may acquire a target size TS corresponding to the pattern of the movement trajectory of the target irradiation area EA#k from the target size table. For example, if the pattern of the movement trajectory of the target irradiation area EA#k is a wave-shaped pattern (e.g., a sine wave shape) shown in FIG. 4B, the control unit 7 may acquire a target size TS corresponding to the wave-shaped (e.g., a sine wave shape) movement trajectory pattern from the target size table. For example, if the pattern of the movement trajectory of the target irradiation area EA#k is a spiral-shaped pattern (e.g., a circular shape whose center position gradually shifts) shown in FIG. 5C, the control unit 7 may acquire a target size TS corresponding to the spiral-shaped (e.g., a circular shape whose center position gradually shifts) movement trajectory pattern from the target size table. Thereafter, the control unit 7 may control the machining system SYS so that the size of the molten pool area MPA becomes the acquired target size TS.

[0317] As described above, the machining system SYS can appropriately change the target size TS by performing the target size changing operation. In particular, by performing the target size changing operation, the machining system SYS can appropriately form a linear object having a desired size even when the machining conditions are changed. Therefore, the machining system SYS can form an object with high formation accuracy.

[0318] (3) Modifications (3-1) First Modification The control unit 7 may be capable of acquiring shape information about the molten pool MP#k formed successively at different positions by the processing light EL#k based on the molten pool image IMG. The control unit 7 may control the processing system SYS based on the shape information.

[0319] The shape information may be information indicating the shape of the weld pool area MPA described above. As described above, the weld pool area MPA corresponds to the area through which the weld pool MP#k moves. In this case, the shape information may be information indicating the shape of the area through which the weld pool MP#k moves. In other words, the shape information may be information indicating the shape of the movement trajectory of the weld pool MP#k.

[0320] The control unit 7 may control the machining system SYS so that the shape of the weld pool region MPA becomes the desired shape. For example, if the shape of the weld pool region MPA differs from the desired shape, the control unit 7 may control the machining system SYS so that the shape of the weld pool region MPA returns to the desired shape. As an example, the control unit 7 may control the intensity of at least one of the processing beams EL#1 emitted by the light source 4#1 and the processing beam EL#2 emitted by the light source 4#2 so that the shape of the weld pool region MPA returns to the desired shape. In other words, the control unit 7 may perform DC modulation control to control the DC component of the intensity of at least one of the processing beams EL#1 and EL#2 so that the shape of the weld pool region MPA returns to the desired shape.

[0321] An example of a desired shape is a shape that is line-symmetric with respect to an axis of symmetry along the movement direction of the machining unit area BSA#k. As an example, FIG. 26( a) shows an example in which the shape of the molten pool area MPA is not line-symmetric with respect to an axis of symmetry (e.g., an axis of symmetry along the X-axis). In this case, as shown in FIG. 27( a), which is a cross-sectional view of a linear object formed when the molten pool area MPA shown in FIG. 26( a) is detected, the height of the left half of the linear object may not be the same as the height of the right half of the linear object. Furthermore, as shown in FIG. 27( b), which is a cross-sectional view of a linear object formed when the molten pool area MPA shown in FIG. 26( a) is detected, the curvature of the corners of the left half of the linear object may not be the same as the curvature of the corners of the right half of the linear object. In other words, the forming accuracy of the linear object may be degraded.

[0322] In this case, the control unit 7 may control the machining system SYS so that the shape of the molten pool region MPA is axisymmetric with respect to an axis of symmetry (for example, an axis of symmetry along the X-axis), as shown in FIG. 26(b). As a result, as shown in FIG. 27(c), which is a cross-sectional view of a linear object formed when the molten pool region MPA shown in FIG. 26(b) is detected, the height of the left half of the linear object is the same as the height of the right half of the linear object. Furthermore, as shown in FIG. 27(d), which is a cross-sectional view of a linear object formed when the molten pool region MPA shown in FIG. 26(b) is detected, the curvature of the corners of the left half of the linear object is the same as the curvature of the corners of the right half of the linear object. In other words, the forming accuracy of the object is improved.

[0323] (3-2) Second Modification The control unit 7 may be capable of acquiring center position information regarding the molten pool MP#k formed successively at different positions by the processing light EL#k based on the molten pool image IMG. The control unit 7 may control the processing system SYS based on the center information.

[0324] The center position information may be information indicating the center position of the weld pool area MPA described above. As described above, the weld pool area MPA corresponds to the area through which the weld pool MP#k moves. In this case, the center position information may be information indicating the center position of the area through which the weld pool MP#k moves. Note that an example of the center position of the weld pool area MPA is the center of gravity of the weld pool area MPA.

[0325] The control unit 7 may control the machining system SYS so that the center position of the weld pool area MPA moves along the desired trajectory. For example, if the center position of the weld pool area MPA is located away from the desired trajectory, the control unit 7 may control the machining system SYS so that the center position of the weld pool area MPA moves along the desired trajectory. As an example, the control unit 7 may control the stroke of at least one of the target irradiation areas EA#1 and EA#2 so that the center position of the weld pool area MPA moves along the desired trajectory. In other words, the control unit 7 may control at least one of the galvanometer mirrors 2146 and 2156, which can control the stroke of at least one of the target irradiation areas EA#1 and EA#2.

[0326] An example of the desired trajectory is the target movement trajectory MTO of the machining unit area BSA#k. In this case, the control unit 7 may control the machining system SYS so that the center position of the molten pool area MPA moves along the target movement trajectory MTO of the machining unit area BSA#k, as shown in Fig. 28(a) . As a result, the control unit 7 can appropriately form a linear object extending along the target movement trajectory MTO of the machining unit area BSA#k, as shown in Fig. 28(b) , which is a cross-sectional view showing a linear object that is formed when the molten pool area MPA shown in Fig. 28(a) is detected. If, as shown in Fig. 28(c), the center position of the weld pool region MPA moves along a movement trajectory different from the target movement trajectory MTO of the machining unit area BSA#k, the control unit 7 will deform the image of the linear object extending in a direction intersecting the target movement trajectory MTO of the machining unit area BSA#k, as shown in Fig. 28(d), which is a cross-sectional view showing a linear object to be formed when the weld pool region MPA shown in Fig. 28(c) is detected. In this case, as shown in Fig. 28(e), the control unit 7 may correct the center position of the weld pool region MPA so that the center position of the weld pool region MPA moves along a movement trajectory different from the target movement trajectory MTO of the machining unit area BSA#k.

[0327] The control unit 7 may control the machining system SYS so that the amount of misalignment in the left-right direction of the center of the molten pool region MPA during the process of stacking the multiple linear objects is equal to or less than a fifth allowable amount. Typically, the control unit 7 may control the machining system SYS so that the center of the molten pool region MPA is positioned at the same position in the left-right direction during the process of stacking the multiple linear objects. For example, as shown in FIG. 29 , the control unit 7 may control the machining system SYS so that the center of the molten pool region MPA-1 detected when forming a first linear object, the center of the molten pool region MPA-2 detected when forming a second linear object on the first linear object, and the center of the molten pool region MPA-N detected when forming an Nth linear object on an N-1th linear object are positioned at the same position in the left-right direction.

[0328] (3-3) Modification The light source 4 included in the processing system SYS may be replaceable. For example, if the processing system SYS includes a first light source 4 that emits processing light EL having a first wavelength, the first light source 4 may be replaced with a second light source 4 that emits processing light EL having a second wavelength different from the first wavelength. For example, if the processing system SYS includes a third light source 4 that emits processing light EL having a first intensity, the third light source 4 may be replaced with a fourth light source 4 that emits processing light EL having a fourth wavelength different from the first intensity. If the processing system SYS includes a light source 4 that has deteriorated over time, the light source 4 may be replaced with a new light source 4.

[0329] The control unit 7 may calculate the intensities of the processing beams EL#1 and EL#2 based on the brightness values ​​of the molten pool area MPA in the molten pool image IMG or the added image IMG_C obtained by imaging the molten pool MP with the imaging unit 8 included in the machining system SYS as described above. The control unit 7 may estimate deterioration of the optical components in the irradiation optical system 211 from the intensities of the processing beams EL#1 and EL#2 estimated from the imaging results of the imaging unit 8 and the intensities of the processing beams EL#1 and EL#2 detected by the power meters 2143 and 2153.

[0330] In the above description, the processing unit 2 melts the shaping material M by irradiating the shaping material M with the processing light EL. However, the processing unit 2 may melt the shaping material M by irradiating the shaping material M with any energy beam. Examples of the any energy beam include at least one of a charged particle beam and an electromagnetic wave. Examples of the charged particle beam include at least one of an electron beam and an ion beam.

[0331] In the above description, the processing unit 2 forms the three-dimensional structure ST by performing additive processing based on the laser build-up welding method. However, the processing unit 2 may form the three-dimensional structure ST by performing additive processing based on other methods capable of forming the three-dimensional structure ST. Examples of other methods capable of forming the three-dimensional structure ST include at least one of powder bed fusion methods such as selective laser sintering (SLS), binder jetting, material jetting, stereolithography, and laser metal fusion (LMF).

[0332] The processing system SYS may perform both additive processing and removal processing. For example, the processing system SYS may perform additive processing using one of the processing lights EL#1 and EL#2, and may perform removal processing using the other of the processing lights EL#1 and EL#2. In this case, the processing system SYS can perform additive processing and removal processing simultaneously. Note th...

Claims

1. a processing device that irradiates an object with an energy beam to form a molten pool in the object and processes the object by supplying a modeling material to the molten pool; an imaging device capable of imaging the molten pool to generate a molten pool image; a control device that generates molten pool image information based on the molten pool image generated by the imaging device, and controls the processing device based on the molten pool image information so that the size of the molten pool area becomes a target size; Equipped with the molten pool image information is generated based on a plurality of the molten pool images captured by the imaging device, The control device changes an imaging condition for the imaging device to image the molten pool based on a processing condition of the object by the processing device. Processing system.

2. the processing device includes an irradiation optical system for irradiating the energy beam, and a position changing device capable of changing a positional relationship between the object and the irradiation optical system, The irradiation optical system includes a deflection optical system capable of moving an irradiation position of the energy beam on the surface of the object by deflecting the energy beam. The processing system of claim 1 .

3. The control device controls the position changing device based on path information so that a model is formed on the object along a target trajectory, and controls the deflection optical system so that an irradiation position of the energy beam moves periodically on a surface of the object along a scanning direction that intersects with the target trajectory. The processing system of claim 2 .

4. The plurality of molten pool images include an image showing a molten pool formed at a first position and an image showing a molten pool formed at a second position different from the first position by the deflection optical system. The processing system according to claim 2 or 3.

5. The control device changes the imaging condition based on a control signal that controls the deflection optical system. The processing system according to claim 2 or 3.

6. The control device performs at least one of the following operations: changing an imaging period for imaging the molten pool based on a speed of movement of the irradiation position; changing an imaging period for imaging the molten pool based on a period of deflection of the energy beam; changing an imaging period for imaging the molten pool based on the speed of deflection of the energy beam; changing an imaging rate for imaging the molten pool based on a speed of movement of the irradiation position; changing an imaging rate for imaging the molten pool based on the period of deflection of the energy beam; and changing an imaging rate for imaging the molten pool based on the speed of deflection of the energy beam. The processing system according to claim 2 or 3.

7. The control device performs at least one of the following operations: shortening an imaging cycle for imaging the molten pool as the speed of movement of the irradiation position becomes faster; shortening an imaging cycle for imaging the molten pool as the period of deflection of the energy beam becomes shorter; shortening an imaging cycle for imaging the molten pool as the speed of deflection of the energy beam becomes faster; increasing an imaging rate for imaging the molten pool as the speed of movement of the irradiation position becomes faster; increasing an imaging rate for imaging the molten pool as the period of deflection of the energy beam becomes shorter; and increasing an imaging rate for imaging the molten pool as the speed of deflection of the energy beam becomes faster. The processing system according to claim 2 or 3.

8. the molten pool image information is generated by adding up the plurality of molten pool images captured by the imaging device; The control device performs at least one of an operation of changing the number of the molten pool images to be added based on a speed of movement of the irradiation position, an operation of changing the number of the molten pool images to be added based on a period of deflection of the energy beam, and an operation of changing the number of the molten pool images to be added based on a speed of deflection of the energy beam. The processing system according to claim 2 or 3.

9. the molten pool image information is generated by adding up the plurality of molten pool images captured by the imaging device; The control device performs at least one of the following operations: increasing the number of the molten pool images to be added as the speed of movement of the irradiation position becomes faster; increasing the number of the molten pool images to be added as the period of deflection of the energy beam becomes shorter; and increasing the number of the molten pool images to be added as the speed of deflection of the energy beam becomes faster. The processing system according to claim 2 or 3.

10. The imaging conditions include a condition regarding a timing at which the imaging device images the molten pool. The processing system according to any one of claims 1 to 3.

11. The imaging conditions include a condition regarding an exposure time for the imaging device to image the molten pool. The processing system according to any one of claims 1 to 3.

12. The imaging conditions include a condition regarding an imaging period or an imaging rate at which the imaging device images the molten pool. The processing system according to any one of claims 1 to 3.

13. The control device controls the imaging device so that the exposure time for imaging the molten pool becomes shorter as the intensity or density of the energy beam becomes higher. The processing system according to any one of claims 1 to 3.

14. the molten pool image information is generated by adding up the plurality of molten pool images captured by the imaging device; The control device increases the number of the molten pool images to be added as the exposure time becomes shorter. The processing system of claim 13.

15. the energy beam is a first energy beam; The deflection optical system is a first deflection optical system, The laser beam irradiation device further includes a second deflection optical system capable of moving an irradiation position of the second energy beam on the surface of the object by deflecting a second energy beam different from the first energy beam on the surface of the object. The processing system according to claim 2 or 3.

16. The processing conditions include at least one of a speed, a period, and a stroke of a movement of an irradiation position of the first energy beam, and at least one of a speed, a period, and a stroke of a movement of an irradiation position of the second energy beam.

16. The processing system of claim 15.

17. The processing conditions include beam conditions regarding the energy beam. The processing system according to any one of claims 1 to 3.

18. the processing device includes an irradiation position moving device capable of moving an irradiation position of the energy beam on the object, The processing conditions include movement mode conditions regarding a movement mode of the irradiation position. The processing system according to any one of claims 1 to 3.

19. The control device changes the imaging conditions so that, when the processing device processes the object based on first processing conditions, the imaging device images the molten pool based on the first imaging conditions, and, when the processing device processes the object based on second processing conditions different from the first processing conditions, the imaging device images the molten pool based on the second imaging conditions different from the first imaging conditions. The processing system according to any one of claims 1 to 3.

20. a processing device including a processing head that irradiates an object with an energy beam to form a molten pool on the object and processes the object by supplying a shaping material to the molten pool, and a position changing device that can change the irradiation position of the energy beam with respect to the processing head; an imaging device provided on the processing head and capable of capturing an image of the molten pool formed by the processing device to generate a molten pool image; a control device that generates molten pool image information based on the molten pool image generated by the imaging device, and controls the processing device based on the molten pool image information so that the size of the molten pool area becomes a target size; Equipped with The molten pool image information is generated based on a plurality of the molten pool images captured by the imaging device. Processing system.

21. The position changing device is a first position changing device, The processing apparatus further includes a second position changing device capable of changing a positional relationship between the object and the processing head, The first position changing device includes a deflection optical system capable of moving an irradiation position of the energy beam on the surface of the object by deflecting the energy beam.

21. The processing system of claim 20.

22. The control device controls the second position changing device based on path information so that a model is formed on the object along a target trajectory, and controls the deflection optical system so that an irradiation position of the energy beam moves periodically on a surface of the object along a scanning direction that intersects with the target trajectory.

22. The processing system of claim 21.

23. The plurality of molten pool images include an image showing a molten pool formed at a first position and an image showing a molten pool formed at a second position different from the first position by the deflection optical system.

23. The processing system according to claim 21 or 22.

24. The control device performs at least one of the following operations: shortening an imaging cycle for imaging the molten pool as the speed of movement of the irradiation position becomes faster; shortening an imaging cycle for imaging the molten pool as the period of deflection of the energy beam becomes shorter; shortening an imaging cycle for imaging the molten pool as the speed of deflection of the energy beam becomes faster; increasing an imaging rate for imaging the molten pool as the speed of movement of the irradiation position becomes faster; increasing an imaging rate for imaging the molten pool as the period of deflection of the energy beam becomes shorter; and increasing an imaging rate for imaging the molten pool as the speed of deflection of the energy beam becomes faster.

23. The processing system according to claim 21 or 22.

25. the molten pool image information is generated by adding up a plurality of the molten pool images captured by the imaging device; The control device performs at least one of the following operations: increasing the number of the molten pool images to be added as the speed of movement of the irradiation position becomes faster; increasing the number of the molten pool images to be added as the period of deflection of the energy beam becomes shorter; and increasing the number of the molten pool images to be added as the speed of deflection of the energy beam becomes faster.

23. The processing system according to claim 21 or 22.

26. The control device changes an imaging condition for the imaging device to image the molten pool, The imaging conditions include a condition regarding a timing at which the imaging device images the molten pool.

23. The processing system according to any one of claims 20 to 22.

27. The control device changes an imaging condition for the imaging device to image the molten pool, The imaging conditions include a condition regarding an exposure time for the imaging device to image the molten pool.

23. The processing system according to any one of claims 20 to 22.

28. The control device changes an imaging condition for the imaging device to image the molten pool, The imaging conditions include a condition regarding an imaging period or an imaging rate at which the imaging device images the molten pool.

23. The processing system according to any one of claims 20 to 22.

29. The control device controls the imaging device so that the exposure time for imaging the molten pool becomes shorter as the intensity or density of the energy beam becomes higher.

23. The processing system according to any one of claims 20 to 22.

30. the molten pool image information is generated by adding up the plurality of molten pool images captured by the imaging device; The control device increases the number of the molten pool images to be added as the exposure time becomes shorter.

30. The processing system of claim 29.

31. The control device changes the imaging conditions under which the imaging device images the molten pool, such that when the processing device processes the object based on first processing conditions, the imaging device images the molten pool based on first imaging conditions, and when the processing device processes the object based on second processing conditions different from the first processing conditions, the imaging device images the molten pool based on second imaging conditions different from the first imaging conditions.

23. The processing system according to any one of claims 20 to 22.

32. a processing device that irradiates an object with an energy beam to form a molten pool in the object and processes the object by supplying a modeling material to the molten pool; an imaging device capable of imaging the molten pool to generate a molten pool image; a control device that calculates a size of a molten pool region in the molten pool image based on a comparison result between the signal value of the molten pool image and a predetermined threshold value, and controls the processing device so that the size of the molten pool region becomes a target size; Equipped with The control device changes the predetermined threshold value based on a processing condition of the object by the processing device. Processing system.

33. the processing device includes an irradiation optical system for irradiating the energy beam, and a position changing device capable of changing a positional relationship between the object and the irradiation optical system, The irradiation optical system includes a deflection optical system capable of moving an irradiation position of the energy beam on the surface of the object by deflecting the energy beam.

33. The processing system of claim 32.

34. The control device controls the position changing device based on path information so that a model is formed on the object along a target trajectory, and controls the deflection optical system so that an irradiation position of the energy beam moves periodically on a surface of the object along a scanning direction that intersects with the target trajectory.

34. The processing system of claim 33.

35. The imaging device generates a plurality of images of the molten pool; the control device calculates a size of the molten pool region in the molten pool image based on a comparison result between the sum of the multiple molten pool images and a predetermined threshold value; The plurality of molten pool images include an image showing a molten pool formed at a first position and an image showing a molten pool formed at a second position different from the first position by the deflection optical system.

35. A processing system according to claim 33 or 34.

36. The control device performs at least one of the following operations: decreasing the threshold value as the speed of movement of the irradiation position increases; decreasing the threshold value as the period of deflection of the energy beam decreases; and decreasing the threshold value as the speed of deflection of the energy beam increases.

35. A processing system according to claim 33 or 34.

37. The control device increases the threshold value as at least one of the intensity and density of the energy beam increases.

35. The processing system of any one of claims 32 to 34.

38. The signal value is a value related to the brightness of the molten pool image.

35. The processing system of any one of claims 32 to 34.

39. The size of the molten pool area is calculated based on the number of pixels whose signal values ​​are greater than the predetermined threshold.

35. The processing system of any one of claims 32 to 34.

40. The processing conditions include beam conditions regarding the energy beam.

35. The processing system of any one of claims 32 to 34.

41. The processing conditions include a movement mode condition regarding a movement mode of the irradiation position of the energy beam by the deflection optical system.

35. The processing system of any one of claims 33 to 34.

42. The control device changes the predetermined threshold so that, when the processing device processes the object based on a first processing condition, the control device calculates the size of the molten pool region by comparing the signal value with a first threshold value as the predetermined threshold value, and, when the processing device processes the object based on a second processing condition different from the first processing condition, the control device calculates the size of the molten pool region by comparing the signal value with a second threshold value different from the first threshold value and as the predetermined threshold value.

35. The processing system of any one of claims 32 to 34.

43. the imaging device captures images of the molten pool multiple times in succession to generate multiple images of the molten pool as time-series data; The control device adds up the signal values ​​of a predetermined number of consecutive molten pool images among the plurality of molten pool images in pixel units, and compares the sum of the signal values ​​with the predetermined threshold value to calculate the size of the molten pool region.

35. The processing system of any one of claims 32 to 34.

44. The control device changes the predetermined number based on the processing conditions.

44. The processing system of claim 43.

45. The control device changes the predetermined number so that, when the processing device processes the object based on first processing conditions, the control device adds up signal values ​​of a first number of the molten pool images in units of pixels, and, when the processing device processes the object based on second processing conditions different from the first processing conditions, the control device adds up signal values ​​of a second number of the molten pool images in units of pixels, the second number being different from the first number.

45. The processing system of claim 44.

46. a processing device that irradiates an object with an energy beam to form a molten pool in the object and processes the object by supplying a modeling material to the molten pool; an imaging device capable of imaging the molten pool to generate a molten pool image; a control device that generates molten pool image information based on the molten pool image generated by the imaging device, and controls the processing device based on the molten pool image information so that the size of the molten pool area becomes a target size; Equipped with The control device changes the target size based on a processing condition of the object by the processing device. Processing system.

47. the processing device includes an irradiation optical system for irradiating the energy beam, and a position changing device capable of changing a positional relationship between the object and the irradiation optical system, The irradiation optical system includes a deflection optical system capable of moving an irradiation position of the energy beam on the surface of the object by deflecting the energy beam.

47. The processing system of claim 46.

48. The control device controls the position changing device based on path information so that a model is formed on the object along a target trajectory, and controls the deflection optical system so that an irradiation position of the energy beam moves periodically on a surface of the object along a scanning direction that intersects with the target trajectory.

48. The processing system of claim 47.

49. The processing conditions include beam conditions regarding the energy beam.

49. The processing system of any one of claims 46 to 48.

50. The control device increases the target size as the intensity or density of the energy beam increases.

50. The processing system of claim 49.

51. the processing device includes an irradiation position moving device capable of moving an irradiation position of the energy beam on the object, The processing conditions include movement mode conditions regarding a movement mode of the irradiation position of the energy beam by the irradiation position moving device.

49. The processing system of any one of claims 46 to 48.

52. the processing conditions include a stroke of movement of the irradiation position of the energy beam, The control device increases the target size as the stroke increases.

49. The processing system of any one of claims 46 to 48.

53. When the processing device processes the object based on a first processing condition, the control device controls the processing device so that the size of the molten pool region becomes a first size as the target size, and when the processing device processes the object based on a second processing condition different from the first processing condition, the control device changes the target size so that the size of the molten pool region becomes a second size different from the first size and as the target size.

49. The processing system of any one of claims 46 to 48.

54. The control device controls the processing device so that the size of the molten pool region becomes the target size, thereby changing the target size so as to form a structure of a desired size on the object.

49. The processing system of any one of claims 46 to 48.

55. a processing device that irradiates an object with an energy beam to form a molten pool in the object and processes the object by supplying a modeling material to the molten pool; an imaging device capable of capturing an image of an area including the molten pool multiple times to generate multiple images; a control device that adds up signal values ​​of each pixel of the plurality of images, and detects at least one of a molten pool region and a non-molten pool region in which at least one of emitted light and reflected light other than the molten pool is captured based on a result of comparing the result of the addition of each pixel with a predetermined threshold value; A processing system comprising:

56. In the non-molten pool region, at least one of spatters generated by scattering of the molten material in the molten pool, fumes generated by evaporation of the molten material in the molten pool, light emission caused by irradiation of the energy beam onto a film on the surface of the object, and the modeling material melted by the energy beam before being supplied to the molten pool is reflected.

56. The processing system of claim 55.

57. the processing device includes an irradiation optical system for irradiating the energy beam, and a position changing device capable of changing a positional relationship between the object and the irradiation optical system, The irradiation optical system includes a deflection optical system capable of moving an irradiation position of the energy beam on the surface of the object by deflecting the energy beam.

57. A processing system according to claim 55 or 56.

58. The control device controls the position changing device based on path information so that a model is formed on the object along a target trajectory, and controls the deflection optical system so that an irradiation position of the energy beam moves periodically on a surface of the object along a scanning direction that intersects with the target trajectory.

58. The processing system of claim 57.

59. The signal values ​​are the luminance values ​​of the image.

57. A processing system according to claim 55 or 56.

60. The control device detects an area including pixels corresponding to an addition result of signal values ​​higher than the threshold as the molten pool area, and detects an area including pixels corresponding to an addition result of brightness values ​​lower than the threshold as the non-molten pool area.

57. A processing system according to claim 55 or 56.

61. The imaging device is capable of generating the images as time series data.

57. A processing system according to claim 55 or 56.

62. The imaging device continuously images the molten pool to generate the plurality of images.

57. A processing system according to claim 55 or 56.

63. a processing device that irradiates an object with an energy beam to form a molten pool in the object and processes the object by supplying a modeling material to the molten pool; an imaging device capable of multiple exposure of an area including the molten pool; a control device that detects at least one of a molten pool region in the image generated by the multiple exposure and a non-molten pool region in which at least one of emitted light and reflected light other than the molten pool is captured by comparing the result of the multiple exposure by the imaging device with a predetermined threshold value; A processing system comprising:

64. In the non-molten pool region, at least one of spatters generated by scattering of the molten material in the molten pool, fumes generated by evaporation of the molten material in the molten pool, light emission caused by irradiation of the energy beam onto a film on the surface of the object, and the modeling material melted by the energy beam before being supplied to the molten pool is reflected.

64. The processing system of claim 63.

65. the processing device includes an irradiation optical system for irradiating the energy beam, and a position changing device capable of changing a positional relationship between the object and the irradiation optical system, The irradiation optical system includes a deflection optical system capable of moving an irradiation position of the energy beam on the surface of the object by deflecting the energy beam.

65. The processing system of claim 63 or 64.

66. The control device controls the position changing device based on path information so that a model is formed on the object along a target trajectory, and controls the deflection optical system so that an irradiation position of the energy beam moves periodically on a surface of the object along a scanning direction that intersects with the target trajectory.

66. The processing system of claim 65.

67. The result of the multiple exposure includes brightness values ​​of the image.

65. The processing system of claim 63 or 64.

68. The control device detects an area including pixels corresponding to a result of multiple exposure higher than the threshold as the molten pool area, and detects an area including pixels corresponding to a result of multiple exposure lower than the threshold as the non-molten pool area.

65. The processing system of claim 63 or 64.

69. a processing device that irradiates an object with an energy beam to form a molten pool in the object and processes the object by supplying a modeling material to the molten pool; an imaging device capable of imaging the molten pool to generate a molten pool image; a control device that generates molten pool image information based on the molten pool image generated by the imaging device, and controls the processing device based on the molten pool image information so that the size of the molten pool area becomes a target size; a recorder for recording information regarding a target size of the molten pool in association with a wobble condition of the energy beam; Equipped with The control device controls the processing device based on the target size of the molten pool acquired from the recording device. Processing system.

70. the processing device includes an irradiation optical system for irradiating the energy beam, and a position changing device capable of changing a positional relationship between the object and the irradiation optical system, The irradiation optical system includes a deflection optical system capable of moving an irradiation position of the energy beam on the surface of the object by deflecting the energy beam.

70. The processing system of claim 69.

71. The control device controls the position changing device based on path information so that a model is formed on the object along a target trajectory, and controls the deflection optical system so that an irradiation position of the energy beam moves periodically on a surface of the object along a scanning direction that intersects with the target trajectory.

71. The processing system of claim 70.

72. a processing device that irradiates an object with an energy beam to form a molten pool in the object and processes the object by supplying a modeling material to the molten pool; an imaging device capable of imaging the molten pool to generate a molten pool image; Control device and Equipped with The control device is capable of acquiring shape information regarding the molten pool continuously formed at different positions by the energy beam based on the molten pool image generated by the imaging device, and controls the processing device based on the shape information. Processing system.

73. the processing device includes an irradiation optical system for irradiating the energy beam, and a position changing device capable of changing a positional relationship between the object and the irradiation optical system, The irradiation optical system includes a deflection optical system capable of moving an irradiation position of the energy beam on the surface of the object by deflecting the energy beam.

73. The processing system of claim 72.

74. The control device controls the position changing device based on path information so that a model is formed on the object along a target trajectory, and controls the deflection optical system so that an irradiation position of the energy beam moves periodically on a surface of the object along a scanning direction that intersects with the target trajectory.

74. The processing system of claim 73.

75. a processing device that irradiates an object with an energy beam to form a molten pool in the object and processes the object by supplying a modeling material to the molten pool; an imaging device capable of imaging the molten pool to generate a molten pool image; Control device and Equipped with The control device can acquire center position information of the molten pool continuously formed at different positions by the energy beam based on the molten pool image generated by the imaging device, and controls the processing device based on the center position information. Processing system.

76. the processing device includes an irradiation optical system for irradiating the energy beam, and a position changing device capable of changing a positional relationship between the object and the irradiation optical system, The irradiation optical system includes a deflection optical system capable of moving an irradiation position of the energy beam on the surface of the object by deflecting the energy beam.

76. The processing system of claim 75.

77. The control device controls the position changing device based on path information so that a model is formed on the object along a target trajectory, and controls the deflection optical system so that an irradiation position of the energy beam moves periodically on a surface of the object along a scanning direction that intersects with the target trajectory.

77. The processing system of claim 76.

78. The path information includes line width information, The control device controls the deflection optical system so that an irradiation position of the energy beam periodically moves within a width of a line formed based on the line width information.

80. The processing system of claim 3, 22, 34, 48, 71, 74 or 77.

79. The control device controls the deflection optical system so that the deflection optical system periodically moves an irradiation position of the energy beam within a target width that indicates a width of a model in a direction intersecting with the target trajectory.

8. The processing system of any one of claims 2 to 3, 21 to 22, 33 to 34, 47 to 48, 70 to 71, 73 to 74 and 76 to 77.

80. The imaging device is capable of imaging the molten pool formed by the energy beam that moves periodically inside the width of the line so that the molten pool falls within an imaging range.

79. The processing system of claim 78.

81. The imaging device is capable of imaging the molten pool formed by the energy beam that periodically moves inside the target width so that the molten pool is within an imaging range.

80. The processing system of claim 79.

82. The molten pool image information is generated based on a plurality of molten pool images obtained by capturing images of the molten pool formed at different positions within an imaging range of the imaging device.

72. The processing system of any one of claims 1 to 3, 20 to 22, 46 to 48 and 69 to 71.

83. The control device controls the deflection optical system to perform a wobbling operation that periodically moves the energy beam.

8. The processing system of any one of claims 21 to 22, 33 to 34, 47 to 48, 70 to 71, 73 to 74 and 76 to 77.

84. The deflection optical system includes a galvanometer mirror.

80. The processing system of any one of claims 21-22, 33-34, 47-48, 70-71, 73-74, and 76-77.

85. The molten pool image information includes information regarding the number of pixels of an image showing the molten pool.

72. The processing system of any one of claims 1 to 3, 20 to 22, 46 to 48, and 69 to 71.

86. The plurality of molten pool images are images obtained by capturing images of a plurality of molten pools each having a different position.

23. The processing system of any one of claims 1 to 3 and 20 to 22.

87. The plurality of images are images of a plurality of molten pools each having a different position.

57. The processing system of any one of claims 55 to 56.

88. The molten pool is movable in a plane intersecting the irradiation direction of the energy beam.

80. The processing system of any one of claims 1 to 3, 20 to 22, 32 to 34, 46 to 48, 55 to 56, 63 to 64, 69 to 77.

89. The molten pool is movable back and forth on an axis intersecting the direction of irradiation of the energy beam.

80. The processing system of any one of claims 1 to 3, 20 to 22, 32 to 34, 46 to 48, 55 to 56, 63 to 64, 69 to 77.

90. The processing conditions are conditions regarding the movement of the irradiation position of the energy beam.

49. The processing system of any one of claims 1 to 3, 32 to 34, and 46 to 48.

91. The processing conditions include at least one of a speed, a period, and a stroke of the movement of the irradiation position of the energy beam.

49. The processing system of any one of claims 1 to 3, 32 to 34, and 46 to 48.

92. a processing device that irradiates an object with an energy beam to form a molten pool in the object and processes the object by supplying a modeling material to the molten pool; an imaging device capable of imaging the molten pool to generate a molten pool image; a control device that generates molten pool image information based on the molten pool image generated by the imaging device, and controls the processing device based on the molten pool image information so that the size of the molten pool area becomes a target size; Equipped with the molten pool image information is generated based on the molten pool image generated by multiple exposure using the imaging device, The control device changes the conditions of the multiple exposure by the imaging device based on the processing conditions of the object by the processing device. Processing system.

93. a processing device including a processing head that irradiates an object with an energy beam to form a molten pool on the object and processes the object by supplying a shaping material to the molten pool, and a position changing device that can change the irradiation position of the energy beam with respect to the processing head; an imaging device provided on the processing head and capable of capturing an image of the molten pool formed by the processing device to generate a molten pool image; a control device that generates molten pool image information based on the molten pool image generated by the imaging device, and controls the processing device based on the molten pool image information so that the size of the molten pool area becomes a target size; Equipped with The molten pool image information is generated based on multiple exposures by the imaging device. Processing system.

94. a processing device that irradiates an object with an energy beam to form a molten pool on the object; an imaging device capable of imaging the molten pool to generate a molten pool image; a control device that generates molten pool image information based on the molten pool image generated by the imaging device and controls the processing device based on the molten pool image information; Equipped with the molten pool image information is generated based on a plurality of the molten pool images captured by the imaging device, The control device changes an imaging condition for the imaging device to image the molten pool based on a processing condition of the object by the processing device. Processing system.

95. a processing device including a processing head that processes an object by irradiating an energy beam onto the object to form a molten pool on the object, and a position changing device that can change an irradiation position of the energy beam with respect to the processing head; an imaging device provided on the processing head and capable of capturing an image of the molten pool formed by the processing device to generate a molten pool image; a control device that generates molten pool image information based on the molten pool image generated by the imaging device and controls the processing device based on the molten pool image information; A processing system comprising:

96. a processing device that processes an object by irradiating an energy beam onto the object to form a molten pool on the object; an imaging device capable of imaging the molten pool to generate a molten pool image; a control device that controls the processing device based on a comparison result between a signal value of the molten pool image and a predetermined threshold value; Equipped with The control device changes the predetermined threshold value based on a processing condition of the object by the processing device. Processing system.

97. a processing device that processes an object by irradiating an energy beam onto the object to form a molten pool on the object; an imaging device capable of imaging the molten pool to generate a molten pool image; a control device that generates molten pool image information based on the molten pool image generated by the imaging device, and controls the processing device based on the molten pool image information so that the size of the molten pool area becomes a target size; Equipped with The control device changes the target size based on a processing condition of the object by the processing device. Processing system.

98. a processing device that processes an object by irradiating an energy beam onto the object to form a molten pool on the object; an imaging device capable of capturing an image of an area including the molten pool multiple times to generate multiple images; a control device that detects at least one of a molten pool region and a non-molten pool region that includes at least one of emitted light and reflected light other than the molten pool in the image based on a result of adding up signal values ​​for each pixel of the plurality of images; A processing system comprising:

99. a processing device that processes an object by irradiating an energy beam onto the object to form a molten pool on the object; an imaging device capable of multiple exposure of an area including the molten pool; a control device that detects at least one of a molten pool region in an image generated by the multiple exposure and a non-molten pool region in which at least one of emitted light and reflected light other than the molten pool is captured based on a result of comparing the result of the multiple exposure by the imaging device with a predetermined threshold value; A processing system comprising:

100. a processing device that processes an object by irradiating an energy beam onto the object to form a molten pool on the object; an imaging device capable of imaging the molten pool to generate a molten pool image; a control device that generates molten pool image information based on the molten pool image generated by the imaging device and controls the processing device based on the molten pool image information; a recorder for recording information regarding a target size of the molten pool in association with a wobble condition of the energy beam; Equipped with The control device controls the processing device based on the target size of the molten pool acquired from the recording device. Processing system.

101. a processing device that processes an object by irradiating an energy beam onto the object to form a molten pool on the object; an imaging device capable of imaging the molten pool to generate a molten pool image; Control device and Equipped with The control device is capable of acquiring shape information regarding the molten pool continuously formed at different positions by the energy beam based on the molten pool image generated by the imaging device, and controls the processing device based on the shape information. Processing system.

102. a processing device that processes an object by irradiating an energy beam onto the object to form a molten pool on the object; an imaging device capable of imaging the molten pool to generate a molten pool image; Control device and Equipped with The control device can acquire center position information of the molten pool continuously formed at different positions by the energy beam based on the molten pool image generated by the imaging device, and controls the processing device based on the center position information. Processing system.

103. a processing device that processes an object by irradiating an energy beam onto the object to form a molten pool on the object; an imaging device capable of imaging the molten pool to generate a molten pool image; a control device that generates molten pool image information based on the molten pool image generated by the imaging device and controls the processing device based on the molten pool image information; Equipped with the molten pool image information is generated based on the molten pool image generated by multiple exposure using the imaging device, The control device changes the conditions of the multiple exposure by the imaging device based on the processing conditions of the object by the processing device. Processing system.

104. a processing device including a processing head that processes an object by irradiating an energy beam onto the object to form a molten pool on the object, and a position changing device that can change an irradiation position of the energy beam with respect to the processing head; an imaging device provided on the processing head and capable of capturing an image of the molten pool formed by the processing device to generate a molten pool image; a control device that generates molten pool image information based on the molten pool image generated by the imaging device and controls the processing device based on the molten pool image information; Equipped with The molten pool image information is generated based on multiple exposures by the imaging device. Processing system.

105. a processing device that irradiates an object with an energy beam to form a molten pool on the object and form a molded object on the object along a target trajectory; an imaging device capable of imaging the molten pool to generate a molten pool image; a control device that controls the processing device based on the molten pool image generated by the imaging device; Equipped with forming a model on the object along the target trajectory includes moving an irradiation position of the energy beam on a surface of the object along a scanning direction that intersects with the target trajectory; The control device controls the processing device based on a plurality of images of the molten pool captured by the imaging device. Processing system.

106. The movement of the irradiation position along the scanning direction includes a periodic movement.

106. The processing system of claim 105.

107. Forming a model on the object along the target trajectory includes periodically moving an irradiation position of the energy beam on a surface of the object in a direction along the target trajectory.

107. The processing system of claim 105 or 106.

108. a processing device that irradiates an object with an energy beam to form a molten pool on the object; an imaging device capable of imaging the molten pool to generate a molten pool image; Equipped with The imaging device is capable of imaging a molten pool appearing at a first position at a first time and a molten pool appearing at a second position different from the first position at a second time different from the first time. Processing system.