Nozzle inspection system and nozzle inspection method

Abstract

To provide a nozzle inspection system that can inspect a lag between the center of an eruption product to be blown out and a shaft center of a nozzle in a qualitative manner.SOLUTION: A nozzle inspection system according to one embodiment comprises an imaging device, a rotation device, and an arithmetic unit. The imaging device captures an eruption product blown out from a nozzle held by a holding part and a calibration component held co-axially with the nozzle by the holding part. The rotation device makes the nozzle or the calibration component rotate relative to the imaging device around a rotation axis extending along a shaft center of the nozzle or a shaft center of the calibration component. The arithmetic unit has a first arithmetic part that calculates a difference between a position of the eruption product and the shaft center of the nozzle in a virtual plane orthogonal to the shaft center of the nozzle based on an image of the eruption product captured by the imaging device and an image of the calibration component captured by the imaging device.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the present invention relate to a nozzle inspection system And a nozzle inspection method and.

Background Art

[0002] A nozzle ejects an ejectant containing at least one of a fluid and a powder. For example, in a stereolithography apparatus, the nozzle ejects a powdery material. The stereolithography apparatus irradiates the material ejected from the nozzle with a laser beam to solidify the material and form a layer of the solidified material. The nozzle of the stereolithography apparatus converges the powder at a desired convergence point.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] For example, due to individual differences in the processing and assembly of the nozzle, there is a possibility that a deviation may occur between the center of the ejected ejectant and the axis of the nozzle. If it becomes possible to quantitatively inspect the deviation, it becomes possible to quantitatively determine whether the nozzle can be used.

[0005] An example of the problem solved by the present invention is a nozzle inspection system capable of quantitatively inspecting the deviation between the center of the ejected ejectant and the axis of the nozzle And a nozzle inspection method is to provide.

Means for Solving the Problems

[0006] A nozzle inspection system according to one embodiment includes a holding unit, an imaging device, a rotating device, and an arithmetic device. The holding unit is a nozzle that ejects an ejectant containing at least one of a fluid and a powder so as to converge at a convergence point is capable of holding, and when not holding the nozzle,A calibration member that is rotationally symmetric about an axis is capable of holding. The nozzle when the holding part holds the nozzle and the calibration member when the holding part holds the calibration member are So as to be coaxial arranged The imaging device is When the nozzle is Held by the holding part at the time of The ejected material ejected from the nozzle imaging, and when the calibration member is Held by the holding part at the time of The calibration member imaging The rotating device is When the nozzle is held by the holding part, The nozzle held by the holding member is rotated relative to the imaging device about a rotation axis extending along the axis of the nozzle or the axis of the calibration member to Rotate relative to the imaging device , when the calibration member is held by the holding part, the calibration member held by the holding part is rotated relative to the imaging device around the rotation axis The arithmetic unit has a first arithmetic unit that calculates the difference between the position of the convergence point in the virtual plane orthogonal to the axis of the nozzle and the position of the axis of the nozzle based on the image of the ejected material captured by the imaging device and the image of the calibration member captured by the imaging device

Brief Description of Drawings

[0007]

Figure 1

Figure 2

Figure 3

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Figure 11

DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, one embodiment will be described with reference to FIGS. 1 to 11. In this specification, basically, vertically upward is defined as the upward direction, and vertically downward is defined as the downward direction. Also, in this specification, the components according to the embodiment and the description of the components may be described in a plurality of expressions. The components and their descriptions are examples and are not limited by the expressions in this specification. The components may be specified by different names from those in this specification. Also, the components may be described by expressions different from those in this specification.

[0009] FIG. 1 is a side view schematically showing a nozzle inspection system 1 according to one embodiment. The nozzle inspection system 1 inspects the quality of the nozzle 2. The nozzle 2 in this embodiment is used for additive manufacturing. Note that the nozzle 2 may be used for other applications.

[0010] FIG. 2 is a cross-sectional view schematically showing the nozzle 2 of this embodiment. As shown in FIG. 2, the nozzle 2 is mounted on a three-dimensional printer 3. The three-dimensional printer 3 forms a three-dimensional object 4 of a predetermined shape by laminating powder materials in layers, for example.

[0011] The additive manufacturing apparatus 3 is, for example, a three-dimensional printer using a so-called Directed Energy Deposition (DED) method or a Laser Metal Deposition (LMD) method. Note that the nozzle 2 may be mounted on another apparatus.

[0012] The nozzle 2 is formed, for example, in a substantially frustum-shaped cylindrical form. Note that the shape of the nozzle 2 is not limited to this example. An emission path 11 and an ejection path 12 are provided in the nozzle 2. The emission path 11 and the ejection path 12 are coaxially arranged and open at the tip 2a of the nozzle 2. The tip 2a is the end of the nozzle 2 in the direction along the axis Axn of the emission path 11 and the ejection path 12. The axis Axn is also the axis of the cylindrical nozzle 2.

[0013] The emission path 11 is a substantially circular hole extending along the axis Axn. In the additive manufacturing apparatus 3, the laser beam L emitted by the oscillation element passes through the emission path 11 and is emitted to the outside of the nozzle 2. In other words, the emission path 11 emits the laser beam L from the tip 2a.

[0014] The ejection path 12 is a substantially annular hole extending along the axis Axn. The ejection path 12 surrounds the emission path 11. In the additive manufacturing apparatus 3, an ejectant Oe containing the powdered material M and the carrier gas G passes through the ejection path 12 and is ejected to the outside of the nozzle 2. In other words, the ejection path 12 ejects the ejectant Oe containing the carrier gas G and the material M from the tip 2a. The powdered material M is, for example, a metal and is an example of a powder. The carrier gas G is, for example, an inert gas such as nitrogen or argon and is an example of a fluid.

[0015] The ejection path 12 extends such that the outer diameter and the inner diameter decrease as it approaches the tip 2a. For this reason, the nozzle 2 ejects the ejectant Oe from the ejection path 12 so as to converge the ejectant Oe at the convergence point P.

[0016] The nozzle 2 may further be provided with a passage through which the shielding gas jets out. The passage surrounds the jetting passage 12 and discharges the shielding gas from the tip 2a or other parts of the nozzle 2. The shielding gas is, for example, an inert gas such as nitrogen or argon.

[0017] The nozzle 2 ejects, for example, the ejecta Oe toward the base or the workpiece of the object 4. Further, the nozzle 2 irradiates the object 4 with the laser beam L. That is, the laser beam L is irradiated from the nozzle 2 in parallel with the supply of the ejecta Oe.

[0018] The additive manufacturing apparatus 3 heats the object 4 and the ejected material M with the laser beam L to melt or sinter them. Thereby, a layer of the material M is formed. The additive manufacturing apparatus 3 may perform an annealing process by irradiating the layer of the material M with the laser beam L. The additive manufacturing apparatus 3 additive manufactures the object 4 by repeatedly stacking the layers of the material M.

[0019] The convergence point P of the ejecta Oe is set to be located on the axis Axn of the nozzle 2. Also, the focus of the laser beam L is set to be located on the axis Axn of the nozzle 2. Thereby, the additive manufacturing apparatus 3 can dispose the focus of the laser beam L at the convergence point P and can efficiently melt or sinter the material M.

[0020] If the convergence point P deviates from the desired position, the efficiency of additive manufacturing by the additive manufacturing apparatus 3 may decrease. For example, when the convergence point P is separated from the axis Axn in a direction orthogonal to the axis Axn, the focus of the laser beam L moves away from the convergence point P, so the efficiency of melting or sintering the material M decreases. Also, when the convergence point P is separated from the desired position in the direction along the axis Axn, it becomes difficult to adjust the focus of the laser beam L to the convergence point P.

[0021] The nozzle 2 may have individual differences in shape due to, for example, the machining accuracy of parts and the assembly accuracy of multiple parts. Due to such individual differences in the machining and assembly of the nozzle 2, there is a possibility that a deviation may occur between the convergence point P of the ejected material Oe and the desired position. For example, a deviation may occur between the convergence point P of the ejected material Oe and the axis Axn of the nozzle 2.

[0022] The nozzle inspection system 1 shown in FIG. 1 can quantitatively inspect the deviation between the convergence point P of the ejected material Oe and the desired position. In other words, the nozzle inspection system 1 can quantitatively inspect the quality of the manufactured nozzle 2.

[0023] As shown in each drawing, in this specification, for convenience, the X-axis, Y-axis, and Z-axis are defined. The X-axis, Y-axis, and Z-axis are orthogonal to each other. The X-axis and Y-axis are provided substantially horizontally. The Z-axis is provided substantially vertically.

[0024] Furthermore, in this specification, the X-direction, Y-direction, and Z-direction are defined. The X-direction is the direction along the X-axis, including the +X direction indicated by the arrow of the X-axis and the -X direction opposite to the arrow of the X-axis. The Y-direction is the direction along the Y-axis, including the +Y direction indicated by the arrow of the Y-axis and the -Y direction opposite to the arrow of the Y-axis. The Z-direction is the direction along the Z-axis, including the +Z direction indicated by the arrow of the Z-axis and the -Z direction opposite to the arrow of the Z-axis. The +Z direction is vertically upward. The -Z direction is vertically downward.

[0025] As shown in FIG. 1, the nozzle inspection system 1 includes a holding device 21, a calibration member 22, a supply device 23, an imaging device 24, an illumination device 25, a rotation device 26, an input device 27, an output device 28, and a control device 29. The supply device 23 is an example of a smoke supply device.

[0026] The holding device 21 holds the nozzle 2 to be inspected or the calibration member 22. Further, the holding device 21 supports the imaging device 24 and the lighting device 25. The holding device 21 includes a base 31, a plurality of columns 32, a support base 33, a holding portion 34, an arm 35, and a screen 36.

[0027] The base 31 is formed, for example, in a plate shape that spreads on the X-Y plane. The X-Y plane is a virtual plane orthogonal to the Z axis. A plurality of X-Y planes exist on each coordinate in the Z direction. The base 31 is disposed, for example, on a substantially horizontal surface. Note that the base 31 is not limited to this example. The column 32 extends from the base 31 in the +Z direction.

[0028] The support base 33 is formed, for example, in a plate shape that spreads on the X-Y plane. The support base 33 is supported by the plurality of columns 32 at a position spaced apart from the base 31 in the +Z direction. The distance between the base 31 and the support base 33 is longer than the length of the nozzle 2 in the direction along the axis Axn.

[0029] The holding portion 34 is provided on the support base 33. The holding portion 34 can selectively hold the nozzle 2 and the calibration member 22. Note that the holding portion 34 may be able to hold other components instead of the nozzle 2 and the calibration member 22.

[0030] The holding portion 34 can hold the nozzle 2 such that the axis Axn extends in the Z direction. Further, the holding portion 34 can hold the calibration member 22 in a state where the nozzle 2 is removed from the holding portion 34. The holding portion 34 holds the nozzle 2 or the calibration member 22 by, for example, a screw, a vise, or other means.

[0031] The calibration member 22 has a plurality of cylinders that are coaxial with each other and have different diameters. Note that the shape of the calibration member 22 is not limited to this example. The holding portion 34 can hold the calibration member 22 such that the axis Axc of the calibration member 22 extends in the Z direction.

[0032] The plurality of cylinders of the calibration member 22 are arranged such that their diameters gradually decrease in the -Z direction. That is, the cylinder with the shortest diameter is arranged at the end of the calibration member 22 in the -Z direction, and the cylinder with the longest diameter is arranged at the end of the calibration member 22 in the +Z direction.

[0033] The holding portion 34 can hold the calibration member 22 such that the axis Axc of the calibration member 22 and the axis Axn of the nozzle 2 are coaxial. That is, on the X-Y plane, the position of the axis Axn of the nozzle 2 held by the holding portion 34 and the position of the axis Axc of the calibration member 22 held by the holding portion 34 are substantially the same.

[0034] For example, the holding portion 34 has a plurality of pins 34a. The nozzle 2 is provided with a plurality of holes spaced apart from the axis Axn in a direction orthogonal to the axis Axn. Further, the calibration member 22 is provided with a plurality of holes spaced apart from the axis Axc in a direction orthogonal to the axis Axc. The plurality of pins 34a are inserted into the holes of the nozzle 2 held by the holding portion 34 or the holes of the calibration member 22 held by the holding portion 34 to position the nozzle 2 and the calibration member coaxially. Note that the holding portion 34 is not limited to this example.

[0035] The arm 35 extends, for example, in the -Y direction from the support base 33. The imaging device 24 and the lighting device 25 are supported by the arm 35. That is, the imaging device 24 and the lighting device 25 are spaced apart from the nozzle 2 or the calibration member 22 held by the holding portion 34 in a direction orthogonal to the axis Axn or the axis Axc. The lighting device 25 is closer to the holding portion 34 than the imaging device 24.

[0036] The screen 36 is formed in a plate shape extending on the X-Z plane. The holding part 34 is located between the imaging device 24 and the screen 36. The screen 36 has a background 36a. The background 36a is a black plane facing the imaging device 24. Note that the holding device 21 may omit the screen 36.

[0037] The supply device 23 is a so-called smoke machine. The supply device 23 is connected to the ejection path 12 of the nozzle 2 held by the holding part 34. The supply device 23 heats, for example, dry ice or a mixture of glycols and water to generate a mist-like liquid. The supply device 23 ejects the mist-like liquid from the nozzle 2 through the ejection path 12. That is, the supply device 23 supplies an ejection Oe as a mist-like liquid to the nozzle 2 held by the holding part 34. The mist-like liquid is an example of a fluid.

[0038] The ejection Oe supplied from the supply device 23 to the nozzle 2 is ejected from the nozzle 2 in a behavior similar to the ejection Oe containing the material M and the carrier gas G. That is, the ejection Oe in the form of a mist converges at substantially the same convergence point P as when the material M and the carrier gas G are ejected from the nozzle 2. Note that the supply device 23 may supply an ejection Oe containing the material M and the carrier gas G to the nozzle 2 held by the holding part 34.

[0039] The imaging device 24 is a digital camera such as a CCD camera, for example, and can image at least one of a still image and a moving image. The imaging device 24 images the ejection Oe ejected from the nozzle 2 held by the holding part 34 and the calibration member 22 held by the holding part 34.

[0040] The lighting device 25 is a ring light, for example, and has a light source such as an LED. The lighting device 25 illuminates the ejection Oe ejected from the nozzle 2 held by the holding part 34 and the calibration member 22 held by the holding part 34. The lighting device 25 may illuminate the ejection Oe and the calibration member 22 from a plurality of directions. The lighting device 25 is arranged outside the field of view of the imaging device 24, for example.

[0041] The lighting device 25 is not limited to the above example. For example, the lighting device 25 may have a light source such as an LED and a half mirror. The half mirror is disposed on the optical axis of the imaging device 24, and the surface that reflects light is directed toward the light source and the ejecta Oe or the calibration member 22, and the surface that transmits light is directed toward the imaging device 24. Thereby, the lighting device 25 can illuminate the ejecta Oe and the calibration member 22 in the same direction as the optical axis of the imaging device 24.

[0042] In the Z direction, the optical axis of the imaging device 24, the optical axis of the lighting device 25, the convergence point P, and the tip 22a of the calibration member 22 are arranged at substantially the same position (coordinates). Thereby, the lighting device 25 can uniformly illuminate the ejecta Oe and the calibration member 22.

[0043] The rotating device 26 rotates, for example, the holding part 34 around a rotation axis Axr extending in the Z direction. Thereby, the rotating device 26 rotates the nozzle 2 or the calibration member 22 held by the holding part 34 around the rotation axis Axr. In other words, the rotating device 26 relatively rotates the nozzle 2 or the calibration member 22 with respect to the imaging device 24. Note that the rotating device 26 may relatively rotate the nozzle 2 or the calibration member 22 with respect to the imaging device 24 by rotating the imaging device 24 around the rotation axis Axr.

[0044] The holding part 34 can hold the nozzle 2 such that the axis Axn and the rotation axis Axr are coaxial. Further, the holding part 34 can hold the calibration member 22 such that the axis Axc and the rotation axis Axr are coaxial.

[0045] The rotation axis Axr may be offset from the axis Axn and the axis Axc. The rotation axis Axr is substantially parallel to the axis Axn and the axis Axc. Further, the nozzle 2 or the calibration member 22 held by the holding part 34 is disposed on the rotation axis Axr. As described above, the rotation axis Axr extends along the axis Axn or the axis Axc.

[0046] The input device 27 is a device that receives input from a user, such as a keyboard, a mouse, and a touch panel. The output device 28 is a device that outputs information, such as a display and a speaker.

[0047] FIG. 3 is a block diagram showing an example of the hardware configuration of the control device 29 of the present embodiment. As shown in FIG. 3, the control device 29 includes, for example, an arithmetic device such as a CPU (Central Processing Unit) 29a, a ROM (Read Only Memorry) 29b, a RAM (Random Access Memorry) 29c, a storage 29d, and an interface (I / F) 29e, and has a hardware configuration using a normal computer. The CPU 29a is an example of an arithmetic device.

[0048] The CPU 29a, the ROM 29b, the RAM 29c, the storage 29d, and the I / F 29e are connected to each other via a bus. The CPU 29a is connected to the supply device 23, the imaging device 24, the lighting device 25, the rotating device 26, the input device 27, and the output device 28 via the I / F 29e.

[0049] By the CPU 29a executing a program incorporated in the ROM 29b or the storage 29d, the control device 29 controls each part of the nozzle inspection system 1. For example, the control device 29 controls the supply device 23, the imaging device 24, the lighting device 25, and the rotating device 26.

[0050] The ROM 29b stores programs and data necessary for program execution. The RAM 29c functions as a work area during program execution. The storage 29d is a device capable of storing, changing, and deleting data, such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive).

[0051] FIG. 4 is a block diagram functionally showing the configuration of the nozzle inspection system 1 of the present embodiment. The control device 29 realizes each part shown in FIG. 4, for example, by reading and executing a program stored in the ROM 29b or the storage 29d by the CPU 29a. As shown in FIG. 4, the control device 29 includes, for example, a storage unit 41, a rotation control unit 42, an imaging control unit 43, a supply control unit 44, an input unit 45, an arithmetic unit 46, a determination unit 47, and an output unit 48. The arithmetic unit 46 is an example of a first arithmetic unit and a second arithmetic unit.

[0052] For example, the RAM 29c and the storage 29d function as the storage unit 41. Also, the CPU 29a functions as the rotation control unit 42, the imaging control unit 43, the supply control unit 44, the input unit 45, the arithmetic unit 46, the determination unit 47, and the output unit 48.

[0053] The storage unit 41 stores various data. The rotation control unit 42 controls the rotation device 26. For example, the rotation control unit 42 rotates the holding unit 34 around the rotation axis Axr by a desired angle by the rotation device 26. The imaging control unit 43 controls the imaging device 24. For example, the imaging control unit 43 starts or stops the imaging of the imaging device 24 and generates image data based on the electrical signal acquired from the imaging device 24 by image processing. Note that the image processing may be performed by the imaging device 24.

[0054] The supply control unit 44 controls the supply device 23. For example, the supply control unit 44 starts or stops the supply of the ejectant Oe by the supply device 23. The input unit 45 receives an input from the input device 27.

[0055] The arithmetic unit 46 includes a binarization unit 51, an axis calculation unit 52, a fitting unit 53, a peak calculation unit 54, and a deviation calculation unit 55. The arithmetic unit 46 calculates the deviation between the convergence point P of the ejectant Oe and a desired position by various calculations. The determination unit 47 determines the quality of the nozzle 2 to be inspected based on the deviation between the convergence point P and the desired position. The output unit 48 outputs the determination result by the determination unit 47 to the output device 28.

[0056] The nozzle inspection system 1 inspects the deviation between the convergence point P on the X-Y plane and the desired position. Further, the nozzle inspection system 1 inspects the deviation between the convergence point P in the Z direction and the desired position. That is, the nozzle inspection system 1 inspects the deviation in the three-dimensional space between the convergence point P and the desired position.

[0057] The desired position of the convergence point P on the X-Y plane is the position of the axis Axn of the nozzle 2. Also, the desired position of the convergence point P in the Z direction is set as a unique value corresponding to the type of the nozzle 2.

[0058] The nozzle inspection system 1 uses the calibration member 22 corresponding to the nozzle 2 to inspect the deviation in the three-dimensional space between the convergence point P and the desired position. The calibration member 22 is manufactured more precisely than the nozzle 2 so as to represent the standard of the desired position of the convergence point P.

[0059] As described above, the calibration member 22 is held coaxially with the nozzle 2 by the holding portion 34. Therefore, the axis Axc of the calibration member 22 represents the desired position of the convergence point P on the X-Y plane.

[0060] In the Z direction, the tip 22a of the calibration member 22 held by the holding portion 34 represents the desired position of the convergence point P in the Z direction. The tip 22a of the calibration member 22 is the end portion of the calibration member 22 held by the holding portion 34 in the -Z direction.

[0061] The calibration member 22 is made corresponding to the nozzle 2. Therefore, when a plurality of types of nozzles 2 are manufactured, a plurality of calibration members 22 having different dimensions from each other are made. Note that one calibration member 22 may correspond to a plurality of types of nozzles 2.

[0062] FIG. 5 is an exemplary flowchart showing an example of the deviation calculation method of the present embodiment. Hereinafter, a method for calculating the deviation between the convergence point P in the three-dimensional space and the desired position by the nozzle inspection system 1 will be described with reference to FIG. 5. Note that the calculation method described below with reference to FIG. 5 is merely an example, and the nozzle inspection system 1 may perform the calculation by other methods.

[0063] First, a calibration member 22 corresponding to the nozzle 2 to be inspected is held by the holding unit 34. Then, the imaging control unit 43 causes the imaging device 24 to image the calibration member 22 (S11).

[0064] FIG. 6 is a diagram schematically showing a first image 61 of the present embodiment and a luminance profile of the first image 61. The imaging control unit 43 generates a first image 61 in which the calibration member 22 is shown based on the output signal of the imaging device 24 that has imaged the calibration member 22. The first image 61 is an example of an image of the calibration member. The imaging control unit 43 stores the first image 61 in the storage unit 41.

[0065] The imaging device 24 images the calibration member 22 so that the tip 22a of the calibration member 22 is shown in the first image 61. As described above, the calibration member 22 has a plurality of cylinders arranged such that the diameter gradually decreases in the -Z direction. Since the cylinder disposed at the end of the calibration member 22 in the -Z direction has a small diameter, it can be imaged by the imaging device 24 at a high magnification. On the other hand, since the plurality of cylinders of the calibration member 22 are arranged such that the diameter gradually increases in the +Z direction, it is possible to suppress a reduction in the rigidity of the calibration member 22.

[0066] Next, as shown in FIG. 5, the calculation unit 46 calculates the axis Axc of the calibration member 22 in the first image 61 (S12). In the calculation unit 46 of the present embodiment, the binarization unit 51 and the axis calculation unit 52 calculate the axis Axc. Note that the calculation unit 46 is not limited to this example.

[0067] The binarization unit 51 acquires the first image 61 from the storage unit 41 and binarizes the first image 61. For example, the binarization unit 51 binarizes the first image 61 by comparing the luminance of each pixel of the first image 61 with a predetermined threshold value.

[0068] In the binarized first image 61, the contour of the calibration member 22 becomes clear. Further, since the background 36a is black, the calibration member 22 in the first image 61 is more surely distinguished from the background 36a.

[0069] As shown in FIG. 6, the axis calculation unit 52 calculates, for example, the luminance profile 62 in the horizontal direction. The axis calculation unit 52 scans the first image 61 at regular intervals from the end of the first image 61 in the -Z direction.

[0070] At the end of the first image 61 in the -Z direction, for example, the background 36a is shown. The luminance of the background 36a is at the lowest level (0) due to binarization. On the other hand, the luminance of the calibration member 22 is at the highest level (1) due to binarization. Therefore, when the scanning at regular intervals reaches the tip 22a of the calibration member 22, the highest level (1) of luminance appears. When the highest level of luminance continues for several pixels, the axis calculation unit 52 tentatively recognizes the coordinate in the Z direction (hereinafter referred to as the temporary tip coordinate) as the tip 22a of the calibration member 22. Since the scanning is performed at regular intervals, the temporary tip coordinate may be different from the coordinate of the tip 22a in the Z direction.

[0071] The axis calculation unit 52 calculates the median value of the range where the luminance is at the highest level at the temporary tip coordinate. The axis calculation unit 52 tentatively recognizes the median value as the coordinate of the axis Axc of the calibration member 22 in the horizontal direction (hereinafter referred to as the temporary axis coordinate). The temporary axis coordinate may be different from the coordinate of the axis Axc in the horizontal direction.

[0072] The axis calculation unit 52 calculates the luminance profile 63 in the Z direction at the provisional axis coordinates. The axis calculation unit 52 recognizes the coordinate of the end in the -Z direction (hereinafter referred to as the tip coordinate) of the range where the luminance is at the highest level as the tip 22a of the calibration member 22. That is, the axis calculation unit 52 calculates the position of the tip 22a of the calibration member 22 in the Z direction. The Z direction is the direction along the axis Axn of the nozzle 2.

[0073] The axis calculation unit 52 calculates the luminance profile 64 in the lateral direction at the tip coordinates. The axis calculation unit 52 calculates the median value of the range where the luminance is at the highest level in the luminance profile 64. The axis calculation unit 52 recognizes the median value as the coordinate of the axis Axc of the calibration member 22 in the lateral direction (hereinafter referred to as the axis coordinate).

[0074] As described above, the axis calculation unit 52 calculates the coordinate (position) of the axis Axc of the calibration member 22 on the X-Y plane based on the binarized first image 61. Since the calibration member 22 is arranged coaxially with the nozzle 2, the calculated coordinate of the axis Axc is substantially equal to the coordinate of the axis Axn of the nozzle 2 on the X-Y plane.

[0075] The axis calculation unit 52 causes the storage unit 41 to store the position (tip coordinate) of the tip 22a of the calibration member 22 in the Z direction and the position (axis coordinate) of the axis Axc of the calibration member 22 on the X-Y plane.

[0076] The storage unit 41 stores height deviation data 66 including the position (tip coordinate) of the tip 22a in the Z direction and plane deviation data 67 including the position (axis coordinate) of the axis Axc on the X-Y plane. The height deviation data 66 includes various data for inspecting the deviation between the convergence point P in the Z direction and the desired position. The plane deviation data 67 includes various data for inspecting the deviation between the convergence point P on the X-Y plane and the desired position.

[0077] Next, as shown in FIG. 5, the imaging control unit 43 determines whether the calibration member 22 has been photographed over the entire circumference (S13). If the photographing of the entire circumference has not been completed (S13: No), the rotation control unit 42 drives the rotating device 26 to rotate the calibration member 22 by a predetermined angle around the rotation axis Axr (S14). The rotation control unit 42 rotates the calibration member 22, for example, by 45°.

[0078] When the rotation control unit 42 rotates the calibration member 22, the imaging control unit 43 obtains the first image 61 after rotation again (S11), and the calculation unit 46 calculates the coordinates of the axis center Axc again (S12). The control device 29 repeats S11 to S14 until the calibration member 22 is photographed over the entire circumference.

[0079] By repeating S11 to S14, the imaging device 24 images the calibration member 22 from a plurality of directions, and the imaging control unit 43 stores a plurality of first images 61 in the storage unit 41. The rotation angle is recorded in association with the plurality of first images 61. The rotation angle is, for example, the rotation angle of the calibration member 22 from when the first first image is captured until the first image 61 is captured. The rotation angle is recorded based on, for example, the detection value of an angular position sensor such as a rotary encoder or an input by the user.

[0080] In this embodiment, the first image 61 is captured every 45° of rotation angle. That is, with the rotation angle at the first imaging being 0°, the storage unit 41 stores the first images 61 at rotation angles of 0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315°. That is, the imaging device 24 images the calibration member 22 from two opposite directions.

[0081] When the imaging control unit 43 captures an image of the calibration member 22 over the entire circumference (S13: Yes), the imaging by the imaging device 24 is stopped (S15). During this time, for example, the user removes the calibration member 22 from the holding unit 34 and causes the holding unit 34 to hold the nozzle 2 to be inspected.

[0082] Next, the supply control unit 44 determines whether the nozzle 2 is attached to the holding unit 34 (S16). For example, the supply control unit 44 waits until the input unit 45 receives an input from the input device 27 by the user who attached the nozzle 2 (S16: No).

[0083] When the supply control unit 44 determines that the nozzle 2 is attached to the holding unit 34 (S16: Yes), the supply control unit 44 causes the nozzle 2 to eject the ejectant Oe (S17). The ejectant Oe ejected from the nozzle 2 converges at the convergence point P.

[0084] FIG. 7 is a diagram schematically showing the second image 71 of the present embodiment and the luminance profile of the second image 71. Next, the imaging control unit 43 causes the imaging device 24 to image the ejectant Oe ejected from the nozzle 2 (S18). The imaging control unit 43 generates a second image 71 in which the ejectant Oe appears. The second image 71 is an example of an image of the ejectant. The imaging control unit 43 stores the second image 71 in the storage unit 41.

[0085] In the present embodiment, the second image 71 includes an image of the convergence point P of the ejectant Oe and the nozzle 2 that ejects the ejectant Oe. Note that the nozzle 2 may not be included in the second image 71.

[0086] Next, the calculation unit 46 calculates the coordinates of the convergence point P of the ejectant Oe in the second image 71 (S19). In the calculation unit 46 of the present embodiment, the fitting unit 53 and the peak calculation unit 54 calculate the coordinates of the convergence point P. Note that the calculation unit 46 is not limited to this example.

[0087] The fitting unit 53 acquires the second image 71 from the storage unit 41 and performs Gaussian fitting on the luminance in the second image 71. That is, the fitting unit 53 performs curve fitting of a Gaussian function on the luminance in the second image 71.

[0088] For example, the fitting unit 53 reads out the position (tip coordinates) of the tip 22a of the calibration member 22 in the Z direction from the height deviation data 66 of the storage unit 41. The fitting unit 53 calculates the luminance profile 72 in the lateral direction at the tip coordinates. The fitting unit 53 performs Gaussian fitting on the profile 72 and calculates a Gaussian function 73. The Gaussian function 73 is an example of the Gaussian-fitted luminance.

[0089] The peak calculation unit 54 calculates the position (coordinates) of the peak 73a of the Gaussian function 73. The position of the peak 73a of the Gaussian function 73 is the lateral coordinate of the second image 71 where the luminance is the highest in the Gaussian function 73.

[0090] Generally, the density of the ejected material Oe ejected from the nozzle 2 is the highest at the convergence point P. Therefore, the luminance of the profile 72 is the highest at the convergence point P. That is, the peak calculation unit 54 calculates the position of the peak 73a of the Gaussian function 73 as the position of the convergence point P (hereinafter referred to as the convergence axis coordinates) in the direction (lateral direction) orthogonal to the axial centers Axn and Axc.

[0091] Furthermore, the fitting unit 53 calculates the luminance profile 74 in the Z direction at the convergence axis coordinates. The fitting unit 53 performs Gaussian fitting on the profile 74 and calculates a Gaussian function 75.

[0092] The peak calculation unit 54 calculates the position (coordinates) of the peak 75a of the Gaussian function 75. The position of the peak 75a of the Gaussian function 75 is the Z-direction coordinate of the second image 71 where the luminance is the highest in the Gaussian function 75. The peak calculation unit 54 calculates the position of the peak 75a of the Gaussian function 75 as the position of the convergence point P in the Z direction.

[0093] The peak calculation unit 54 causes the storage unit 41 to store the position of the convergence point P in the Z direction as the height deviation data 66. Further, the peak calculation unit 54 stores the position of the convergence point P in the lateral direction as the in-plane deviation data 67.

[0094] Next, as shown in FIG. 5, the deviation calculation unit 55 calculates the deviation between the position of the convergence point P in the second image 71 and the calibration member 22 (S20). For example, the deviation calculation unit 55 acquires the position (tip coordinate) of the tip 22a in the Z direction related to the first image 61 associated with the current rotation angle from the height deviation data 66.

[0095] The deviation calculation unit 55 calculates, for example, the difference between the position of the convergence point P in the Z direction and the position of the tip 22a of the calibration member 22 by subtracting the tip coordinate from the position of the convergence point P in the Z direction calculated by the peak calculation unit 54. That is, the deviation calculation unit 55 calculates the difference (deviation) between the position of the convergence point P in the Z direction and the position of the tip 22a of the calibration member 22 based on the first image 61 and the second image 71. The deviation calculation unit 55 stores the deviation between the position of the convergence point P in the Z direction and the position of the tip 22a of the calibration member 22 in the storage unit 41 as the height deviation data 66.

[0096] Furthermore, the deviation calculation unit 55 obtains the position (axis coordinates) of the axis Axc in the lateral direction related to the first image 61 associated with the current rotation angle from the in-plane deviation data 67. For example, the deviation calculation unit 55 calculates a provisional difference (deviation) between the position of the convergence point P in the lateral direction and the position of the axis Axc by subtracting the axis coordinates from the position of the convergence point P in the lateral direction calculated by the peak calculation unit 54. The deviation calculation unit 55 stores the provisional deviation between the position of the convergence point P in the lateral direction and the position of the axis Axc in the storage unit 41 as the in-plane deviation data 67.

[0097] Next, the imaging control unit 43 determines whether the ejecta Oe has been imaged over the entire circumference (S21). If the imaging of the entire circumference is not completed (S21: No), the rotation control unit 42 drives the rotating device 26 to rotate the nozzle 2 by a predetermined angle around the rotation axis Axr (S22). The rotation control unit 42 rotates the nozzle 2, for example, by 45°.

[0098] When the rotation control unit 42 rotates the nozzle 2, the imaging control unit 43 obtains the second image 71 after rotation again (S18), and the calculation unit 46 calculates the position of the convergence point P again (S19). Further, the calculation unit 46 calculates the deviation between the position of the convergence point P and the calibration member 22 again (S20). The control device 29 repeats S18 to S22 until the calibration member 22 is imaged over the entire circumference.

[0099] By repeating S18 to S22, the imaging device 24 images the ejecta Oe from a plurality of directions, and the imaging control unit 43 stores the plurality of second images 71 in the storage unit 41. The rotation angle is recorded in association with the plurality of second images 71. The rotation angle is, for example, the rotation angle of the calibration member 22 from when the first second image 71 is imaged until the second image 71 is imaged. The rotation angle is recorded based on, for example, the detection value of an angular position sensor such as a rotary encoder or an input by the user.

[0100] In this embodiment, the second image 71 is captured every 45° of rotation angle. That is, assuming the rotation angle in the first capture is 0°, the storage unit 41 stores the second images 71 at rotation angles of 0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315°. That is, the imaging device 24 captures the ejecta Oe from two opposite directions.

[0101] When the ejecta Oe is photographed over the entire circumference (S21: Yes), the imaging control unit 43 stops the imaging by the imaging device 24, and the supply control unit 44 stops the ejection of the ejecta Oe by the nozzle 2 (S23).

[0102] As described above, the deviation calculation unit 55 calculates a provisional difference (deviation) between the position of the convergence point P in the horizontal direction and the position of the axis Axc for a plurality of rotation angles. The deviation in the horizontal direction for each rotation angle does not have information on the deviation in the direction along the optical axis of the imaging device 24 (depth). Therefore, the deviation calculation unit 55 calculates the difference (deviation) between the position of the convergence point P and the position of the axis Axc on the X-Y plane based on the deviations for a plurality of angles, as described below.

[0103] FIG. 8 is a plan view schematically showing the nozzle 2 and the imaging device 24 of this embodiment. In this embodiment, the rotating device 26 rotates the nozzle 2 or the calibration member 22. However, in the following description, for the sake of understanding, it is assumed that the imaging device 24 rotates around the rotation axis Axr as shown in FIG. 8 and described. Note that both the case where the nozzle 2 or the calibration member 22 rotates and the case where the imaging device 24 rotates are common in that the nozzle 2 or the calibration member 22 rotates relative to the imaging device 24.

[0104] The parentheses in FIG. 8 indicate the rotation angle of the imaging device 24. The rotation angle in the following description is the rotation angle when the imaging device 24 captures the second image 71 with the nozzle 2 fixed, as shown in FIG. 8.

[0105] FIG. 9 is a plan view schematically showing the deviation D on the virtual plane Pxy at each rotation angle of the present embodiment. As described above, the temporary difference (deviation) D between the position of the convergence point P in the horizontal direction and the position of the axis Axc for each rotation angle does not have information on the deviation in the direction (depth) along the optical axis of the imaging device 24. The deviation calculation unit 55 of the present embodiment arranges the deviation D on the virtual plane Pxy orthogonal to the axis Axc of the nozzle 2 on a virtual straight line orthogonal to the optical axis of the imaging device 24 at each rotation angle and passing through the axis Axn. The virtual plane Pxy in the present embodiment is the X-Y plane.

[0106] As shown in FIG. 9, the deviation D(0°) at a rotation angle of 0° and the deviation D(180°) at a rotation angle of 180° are arranged on the same virtual straight line. Similarly, for example, the deviation D(45°) at a rotation angle of 45° and the deviation D(225°) at a rotation angle of 225° are arranged on the same virtual straight line. The same applies to other angles.

[0107] The positions of the deviation D in the horizontal direction at two mutually opposite rotation angles (directions) can theoretically coincide. However, the second images 71 at two mutually opposite rotation angles are taken at different times. For this reason, a deviation occurs in the positions of the deviation D in the horizontal direction at two mutually opposite rotation angles due to the fluctuation.

[0108] FIG. 10 is a plan view schematically showing the deviation D, the midpoint Ph, and the in-plane deviation Dp of the present embodiment. As shown in FIG. 10, the deviation calculation unit 55 calculates the midpoint Ph of the deviation D in the horizontal direction at two mutually opposite rotation angles (directions) (S24). In other words, the deviation calculation unit 55 calculates the midpoint Ph of the two deviations D arranged on the same virtual straight line. The parentheses attached to the midpoint Ph in FIG. 10 indicate the rotation angle of the deviation D that is the basis of the midpoint Ph.

[0109] As shown in FIG. 10, the deviation calculation unit 55 calculates a virtual straight line L2 that is orthogonal to a virtual straight line L1 connecting the midpoint Ph and the axis center Axn and passes through the midpoint Ph. The virtual straight line L1 is substantially orthogonal to the optical axis of the imaging device 24 at each rotation angle. The virtual straight line L2 extends substantially parallel to the optical axis of the imaging device 24 at each rotation angle. Further, the deviation calculation unit 55 calculates an intersection point Pc of a plurality of virtual straight lines L2 (S25).

[0110] The deviation calculation unit 55 acquires a plurality of X coordinates and Y coordinates at which a plurality of intersection points Pc are arranged. In the example of FIG. 10, the deviation calculation unit 55 acquires three coordinates in the X direction at which a plurality of intersection points Pc are arranged. Further, the deviation calculation unit 55 acquires three coordinates in the Y direction at which a plurality of intersection points Pc are arranged.

[0111] In the example of FIG. 10, the virtual straight line L2 of the midpoint Ph (0°, 180°) extends in the Y direction, and three intersection points Pc are located on the virtual straight line L2. Further, the virtual straight line L2 of the midpoint Ph (90°, 270°) extends in the X direction, and three intersection points Pc are located on the virtual straight line L2.

[0112] The deviation calculation unit 55 calculates an average value (average X coordinate) of three coordinates in the X direction at which a plurality of intersection points Pc are arranged. Further, the deviation calculation unit 55 calculates an average value (average Y coordinate) of three coordinates in the Y direction at which a plurality of intersection points Pc are arranged. The deviation calculation unit 55 calculates a plane deviation Dp on the virtual plane Pxy, where the X-direction coordinate is the average X coordinate and the Y-direction coordinate is the average Y coordinate, as the difference between the convergence point P of the ejecta Oe on the virtual plane Pxy and the position of the axis center Axn of the nozzle 2 (S26).

[0113] As described above, the deviation calculation unit 55 calculates the difference (plane deviation Dp) between the position of the convergence point P as the position of the ejecta Oe in the virtual plane Pxy orthogonal to the axis center Axn of the nozzle 2 and the position of the axis center Axn of the nozzle 2 based on the first image 61 and the second image 71. Note that the deviation calculation unit 55 may omit the calculation of the midpoint Ph, the virtual straight lines L1 and L2, and the intersection point Pc. For example, the deviation calculation unit 55 may calculate the average coordinates of a plurality of deviations D as the plane deviation Dp.

[0114] Next, as shown in FIG. 5, the deviation calculation unit 55 calculates the difference between the position of the convergence point P of the ejecta Oe in the Z direction and the position of the tip 22a of the calibration member 22 (S27). For example, the deviation calculation unit 55 calculates the average value of the differences (deviations) at each rotation angle between the position of the convergence point P in the Z direction and the position of the tip 22a of the calibration member 22. The deviation calculation unit 55 calculates the average value as the difference between the position of the convergence point P of the ejecta Oe in the Z direction and the position of the tip 22a of the calibration member 22.

[0115] The deviation calculation unit 55 causes the storage unit 41 to record, as the height deviation data 66, the difference (average value) between the position of the convergence point P in the Z direction and the position of the tip 22a of the calibration member 22. Further, the deviation calculation unit 55 causes the storage unit 41 to record, as the in-plane deviation data 67, the difference (in-plane deviation Dp) between the position of the convergence point P in the virtual plane Pxy (X-Y plane) and the position of the axis Axn of the nozzle 2 (S28). As described above, the arithmetic unit 46 of the nozzle inspection system 1 calculates the deviation between the convergence point P in the three-dimensional space and the desired position.

[0116] In the above deviation calculation method, in S11 to S15, the tip coordinates and the axis coordinates of the calibration member 22 are calculated. However, for example, for a plurality of nozzles 2 corresponding to the same calibration member 22, there may be cases where the deviations between the convergence point P and the axis Axn of the nozzle 2 and the tip 22a of the calibration member 22 are measured. In this case, in the deviation calculation for the second and subsequent nozzles 2, S11 to S15 may be omitted, and the tip coordinates and the axis coordinates of the calibration member 22 measured first may be used.

[0117] FIG. 11 is an exemplary flowchart showing an example of the inspection method of the nozzle 2 of the present embodiment. Hereinafter, the inspection method of the nozzle 2 by the nozzle inspection system 1 will be described with reference to FIG. 11. Note that the inspection method described below with reference to FIG. 11 is merely an example, and the nozzle inspection system 1 may perform the inspection by other methods.

[0118] First, the determination unit 47 reads out the difference (in-plane deviation Dp) between the position of the convergence point P in the X-Y plane and the position of the axis Axn of the nozzle 2 from the in-plane deviation data 67 in the storage unit 41. The determination unit 47 determines whether or not the in-plane deviation Dp exceeds a threshold value (S101). For example, the determination unit 47 compares the distance between the axis Axn and the coordinates of the in-plane deviation Dp with the threshold value.

[0119] When the in-plane deviation Dp does not exceed the threshold value (S101: No), the determination unit 47 reads out the difference (height deviation) between the position of the convergence point P in the Z direction and the position of the tip 22a of the calibration member 22 from the height deviation data 66 in the storage unit 41. The determination unit 47 determines whether or not the height deviation exceeds a threshold value (S102).

[0120] When the height deviation does not exceed the threshold value (S102: No), the output unit 48 causes the output device 28 to output the determination result by the determination unit 47. For example, the above-described threshold value is determined according to the operation method of the additive manufacturing apparatus 3 and the shaping process. That is, when the in-plane deviation Dp and the height deviation do not exceed the threshold value, the determination unit 47 determines that the nozzle 2 conforms to the operation conditions by the additive manufacturing apparatus 3, and determines that the quality of the nozzle 2 has reached a level that allows shipment. Therefore, the output unit 48 causes the output device 28 to output a determination that the shipment of the nozzle 2 is permitted (S103).

[0121] On the other hand, when the in-plane deviation Dp exceeds the threshold value (S101: Yes), or when the height deviation exceeds the threshold value (S102: Yes), the determination unit 47 determines that the nozzle 2 does not conform to the operation conditions by the additive manufacturing apparatus 3, and determines that the quality of the nozzle 2 is below the level that allows shipment. Therefore, the output unit 48 causes the output device 28 to output a determination that the shipment of the nozzle 2 is not permitted (S104).

[0122] As described above, the nozzle inspection system 1 inspects the quality of the nozzle 2. The nozzle inspection system 1 inspects the nozzle 2 based on the quantitatively calculated in-plane deviation Dp and height deviation. Therefore, the nozzle inspection system 1 can more reliably inspect the quality of the nozzle 2. Note that after the above determination, the nozzle 2 may be further inspected.

[0123] In the above nozzle inspection system 1, the nozzle 2 and the calibration member 22 were imaged by the imaging device 24 while being attached to the holding portion 34 of the holding device 21. However, the nozzle inspection system 1 is not limited to this example. For example, the nozzle 2 and the calibration member 22 may be imaged by the imaging device 24 while being attached to the additive manufacturing apparatus 3.

[0124] In the nozzle inspection system 1 according to the embodiment described above, the rotating device 26 rotates the nozzle 2 or the calibration member 22 relative to the imaging device 24 around the rotation axis Axr extending along the axis Axn of the nozzle 2 or the axis Axc of the calibration member 22. The calculation unit 46 of the control device 29 calculates the difference (in-plane deviation Dp) between the position of the ejection Oe in the virtual plane Pxy orthogonal to the axis Axn of the nozzle 2 and the position of the axis Axn of the nozzle 2 based on the second image 71 of the ejection Oe and the first image 61 of the calibration member 22. Thereby, the nozzle inspection system 1 can quantitatively inspect the deviation in the virtual plane Pxy between the center of the ejection Oe ejected from the nozzle 2 and the axis Axn of the nozzle 2, which is caused by, for example, individual differences in the processing and assembly of the nozzle 2. Therefore, the nozzle inspection system 1 can quantitatively inspect the quality of the nozzle 2.

[0125] The calibration member 22 can be selectively held by the holding portion 34 with the nozzle 2. In other words, the calibration member 22 and the nozzle 2 can be replaced in the common holding portion 34. Thereby, the complication of the holding portion 34 is suppressed.

[0126] The binarization unit 51 binarizes the first image 61 of the calibration member 22. The axis center calculation unit 52 calculates the position of the axis center Axc of the calibration member 22 coaxial with the nozzle 2 based on the binarized first image 61 of the calibration member 22. By binarization, the contour of the calibration member 22 in the first image 61 becomes clear. As a result, the calculation unit 46 can more accurately obtain the position of the axis center Axn of the nozzle 2 in the direction orthogonal to the axis center Axn of the nozzle 2.

[0127] The nozzle 2 converges the ejected ejecta Oe at the convergence point P. The calculation unit 46 uses the position of the convergence point P as the position of the ejecta Oe. As a result, the nozzle inspection system 1 can more quantitatively inspect the deviation between the center of the ejecta Oe ejected from the nozzle 2 and the axis center Axn of the nozzle 2 in the virtual plane Pxy orthogonal to the axis center Axn of the nozzle 2.

[0128] The calculation unit 46 includes a fitting unit 53 that performs Gaussian fitting on the luminance in the second image 71 of the ejecta Oe, and a peak calculation unit 54 that calculates the position of the peak 73a of the luminance Gaussian-fitted as the position of the convergence point P in the direction orthogonal to the axis center Axn of the nozzle 2. Since the ejecta Oe converges at the convergence point P, the luminance at the convergence point P becomes the highest. Therefore, the calculation unit 46 can more easily obtain the position of the convergence point P in the direction orthogonal to the axis center Axn of the nozzle 2.

[0129] The calculation unit 46 calculates the difference between the position of the convergence point P in the Z direction along the axis center Axn of the nozzle 2 and the position of the tip 22a of the calibration member 22 based on the second image 71 of the ejecta Oe and the first image 61 of the calibration member 22. As a result, the nozzle inspection system 1 can quantitatively inspect the deviation in the three-dimensional space between the position of the convergence point P of the ejecta Oe ejected from the nozzle 2 and the desired position. Therefore, the nozzle inspection system 1 can quantitatively inspect the quality of the nozzle 2.

[0130] The rotating device 26 rotates the nozzle 2 and the calibration member 22. Thereby, even if there are obstacles such as the pillar 32 around the nozzle 2 and the calibration member 22, the imaging device 24 can image the entire circumference of the nozzle 2 and the calibration member 22.

[0131] The imaging device 24 images the ejected matter Oe from two opposite directions. The positions of the ejected matter Oe imaged from two opposite directions are theoretically located at the same coordinates. However, there is a fluctuation in the position of the ejected matter Oe ejected from the nozzle 2. By imaging the ejected matter Oe from two directions, the control device 29 can average the position of the ejected matter Oe from the second images 71 imaged from the two directions. Thereby, the nozzle inspection system 1 can more accurately inspect the deviation between the position of the ejected matter Oe ejected from the nozzle 2 and the desired position.

[0132] The supply device 23 supplies the ejected matter Oe as a mist-like liquid to the nozzle 2 held by the holding portion 34. That is, even if the nozzle 2 is used for ejecting the powdery material M, the nozzle inspection system 1 can eject a mist-like liquid during inspection. Generally, liquids are easier to remove than powders. This facilitates the cleaning of the nozzle 2 after inspection.

[0133] The determination unit 47 determines whether or not the difference between the position of the ejected matter Oe in the virtual plane Pxy orthogonal to the axis Axn of the nozzle 2 and the position of the axis Axn of the nozzle 2 exceeds a threshold value. The output unit 48 outputs the determination result by the determination unit 47. Thereby, the nozzle inspection system 1 automatically outputs the inspection result of the quality of the nozzle 2, facilitating the inspection of the quality of the nozzle 2.

[0134] The program executed by the control device 29 of the present embodiment is provided by being recorded on a computer-readable recording medium such as a CD-ROM, a flexible disk (FD), a CD-R, or a DVD (Digital Versatile Disk) in an installable format or an executable format file.

[0135] Alternatively, the program executed by the control device 29 of the present embodiment may be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network. Further, the program executed by the control device 29 of the present embodiment may be configured to be provided or distributed via a network such as the Internet.

[0136] Alternatively, the program of the present embodiment may be configured to be provided by being pre - incorporated into a ROM or the like.

[0137] The program executed by the control device 29 of the present embodiment has a module configuration including the above - described respective parts (rotation control unit 42, imaging control unit 43, supply control unit 44, input unit 45, arithmetic unit 46, determination unit 47, and output unit 48). As actual hardware, the CPU 29a (processor) reads the program from the above - described storage medium and executes it, whereby the above - described respective parts are loaded onto the main storage device, and the rotation control unit 42, imaging control unit 43, supply control unit 44, input unit 45, arithmetic unit 46, determination unit 47, and output unit 48 are generated on the main storage device.

[0138] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention and are also included in the invention described in the claims and its equivalent scope.

Explanation of Reference Numerals

[0139] 1... Nozzle inspection system, 2... Nozzle, 22... Calibration member, 22a... Tip, 23... Supply device, 24... Imaging device, 26... Rotation device, 29... Control device, 34... Holding part, 46... Calculation part, 47... Judgment part, 48... Output part, 51... Binarization part, 52... Axis calculation part, 53... Fitting part, 54... Peak calculation part, 61... First image, 71... Second image, 73... Gaussian function, 73a... Peak, Axn, Axc... Axis, Axr... Rotation axis, Oe... Ejection, P... Convergence point, M... Material, G... Carrier gas, Pxy... Virtual plane, Dp... Deviation on the plane.

Claims

1. A holding unit capable of holding a nozzle that ejects an ejectant containing at least one of a fluid and a powder so as to converge at a convergence point, and capable of holding a calibration member that is rotationally symmetric about an axis when the nozzle is not held, and the nozzle when holding the nozzle and the calibration member when holding the calibration member are arranged coaxially with each other; An imaging device that images the ejectant ejected from the nozzle when the nozzle is held by the holding unit, and images the calibration member when the calibration member is held by the holding unit; A rotating device that rotates the nozzle held by the holding unit relative to the imaging device about a rotation axis extending along the axis of the nozzle or the axis of the calibration member when the nozzle is held by the holding unit, and rotates the calibration member held by the holding unit relative to the imaging device about the rotation axis when the calibration member is held by the holding unit; An arithmetic device having a first arithmetic unit that calculates a difference between a position of the convergence point and a position of the axis of the nozzle in a virtual plane orthogonal to the axis of the nozzle based on an image of the ejectant imaged by the imaging device and an image of the calibration member imaged by the imaging device; A nozzle inspection system comprising the same.

2. The nozzle inspection system according to Claim 1, wherein the first arithmetic unit includes a binarization unit that binarizes an image of the calibration member, and an axis calculation unit that calculates a median value of a coordinate range having a luminance level indicating the presence of the calibration member in a direction orthogonal to the axis of the calibration member in the binarized image of the calibration member as the position of the axis of the calibration member.

3. The first arithmetic unit includes a fitting unit that performs Gaussian fitting on the luminance in the image of the ejected material, and a peak calculation unit that calculates the position of the peak of the luminance Gaussian-fitted as the position of the convergence point in the direction orthogonal to the axis of the nozzle. The nozzle inspection system according to claim 2.

4. The arithmetic device further includes a second arithmetic unit that calculates the difference between the position of the convergence point in the direction along the axis of the nozzle and the position of the tip of the calibration member based on the image of the ejected material captured by the imaging device and the image of the calibration member captured by the imaging device. The nozzle inspection system according to any one of claims 1 to 3.

5. The rotating device rotates the nozzle when the nozzle is held by the holding unit, and rotates the calibration member when the calibration member is held by the holding unit. The nozzle inspection system according to any one of claims 1 to 4.

6. The imaging device captures the ejected material from two opposite directions when the nozzle is held by the holding unit. The nozzle inspection system according to any one of claims 1 to 5.

7. The nozzle inspection system according to any one of claims 1 to 6, further comprising a smoke supply device that supplies the ejected material as a mist-like liquid to the nozzle when the nozzle is held by the holding unit.

8. A determination unit that determines whether the difference between the position of the convergence point in the virtual plane orthogonal to the axis of the nozzle and the position of the axis of the nozzle exceeds a threshold value; An output unit that outputs the determination result by the determination unit; The nozzle inspection system according to any one of claims 1 to 7, further comprising the above.

9. Causing the holding unit to hold a calibration member that is rotationally symmetric about an axis; Imaging the calibration member held by the holding part with an imaging device; Rotating the calibration member held by the holding part relative to the imaging device by a rotating device about a rotation axis extending along the axis of the calibration member; Causing a nozzle that ejects an ejectant containing at least one of a fluid and a powder to be held by the holding part so as to be coaxial with the calibration member, such that the ejectant is ejected to converge at a convergence point; Imaging the ejectant ejected from the nozzle held by the holding part with the imaging device; Rotating the nozzle held by the holding part relative to the imaging device by the rotating device about the rotation axis; Based on a plurality of images of the ejectant imaged by the imaging device from a plurality of angles and a plurality of images of the calibration member imaged by the imaging device from a plurality of angles, calculating, by an arithmetic device, a difference between the position of the convergence point in a virtual plane orthogonal to the axis of the nozzle and the position of the axis of the nozzle; A nozzle inspection method comprising the above.

10. Based on a plurality of images of the ejectant imaged by the imaging device from a plurality of angles and a plurality of images of the calibration member imaged by the imaging device from a plurality of angles, calculating, by the arithmetic device, a difference between the position of the convergence point in the direction along the axis of the nozzle and the position of the tip of the calibration member; The nozzle inspection method according to claim 9, further comprising the above.

Images