Laser marker and marker head

Abstract

To widen the imaging visual field of an imaging part while suppressing the load of a control system.SOLUTION: A laser machining device L includes a transmission window 19 for emitting a laser beam to the outside of a housing 10, a transparent member 19b through which the laser beam emitted from the transmission window 19 is transmitted, and a wide area camera 6 for generating a workpiece image Pw including at least a part of a machining area R1 by imaging a workpiece W through the transmission window 19. The transparent member 19b is formed of a flat member having substantially no lens effect, and the wide area camera 6 is disposed in the housing 10 in a posture in which an imaging optical axis Ac thereof and a processing reference surface Rb serving as a reference of position information are orthogonal to each other.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The technology disclosed herein relates to a laser processing device, such as a laser marking device, that processes a workpiece by irradiating the workpiece with laser light. [Background technology]

[0002] 2. Description of the Related Art Laser processing devices equipped with an imaging unit such as a camera are known.

[0003] For example, Patent Document 1 discloses a laser processing device (laser marking device) that includes a laser light source that emits laser light, a scanning means that scans the laser light two-dimensionally, and an imaging means that images an object to be marked.

[0004] The imaging means according to Patent Document 1 is configured so that its imaging optical axis is coaxial with the laser light for processing. Specifically, the laser processing device disclosed in Patent Document 1 includes an optical path branching means for branching an optical path between the laser light source and the scanning means, and the imaging means according to the same document is provided so that the optical axis directed toward the scanning means via the optical path branching means coincides with the optical axis of the laser light.

[0005] Patent Document 2 discloses a laser processing device that includes a marker laser head that emits laser light for processing a workpiece, and an observation optical system that captures an image of the processed surface of the workpiece.

[0006] The laser head disclosed in Patent Document 2 houses a scanning means for scanning the laser light on the processing surface, and the observation optical system disclosed in the same document is provided between the scanning means and the processing surface in the height direction. Specifically, the observation optical system disclosed in Patent Document 2 is disposed below the bottom surface of the laser head. This observation optical system is non-coaxial with respect to the optical axis of the laser light, and is configured to image the processing surface from diagonally above. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-148379 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-44212 Summary of the Invention [Problem to be solved by the invention]

[0008] When using an imaging means such as that described in Patent Document 1, the size of the imaging field of view depends on the configuration of the scanning means. In particular, when the scanning means is configured using a galvanometer mirror, the size of the imaging field of view of the imaging means increases or decreases depending on the area of ​​the galvanometer mirror. A typical galvanometer mirror is disadvantageous because it can only capture a portion of the surface of the workpiece.

[0009] On the other hand, as described in Patent Document 2, it is conceivable to place the imaging unit as an observation optical system below the bottom surface of the laser head. With this arrangement, it is possible to capture images of a wide range of the workpiece, but since the images are captured from an oblique direction, distortion occurs in the captured images. In order to eliminate the distortion in the captured images, image processing such as distortion correction is required, which places an extra load on the control system of the laser processing device.

[0010] Therefore, it is conceivable to house the imaging unit disclosed in Patent Document 2, for example, inside the laser head. In such an arrangement, the workpiece can be imaged from directly above through an exit window for emitting the laser light. However, an fθ lens for focusing the laser light for processing is typically fitted into the exit window. If the workpiece is imaged through this fθ lens, the image will be distorted, which again places an extra load on the control system.

[0011] The technology disclosed herein has been made in consideration of the above points, and its purpose is to widen the imaging field of view of the imaging unit while suppressing the load on the control system. [Means for solving the problem]

[0012] Specifically, a first aspect of the present disclosure relates to a laser processing device comprising: an excitation light generation unit that generates excitation light; a laser light output unit that generates laser light based on the excitation light generated by the excitation light generation unit and emits the laser light; a laser light scanning unit that irradiates a workpiece with the laser light emitted from the laser light output unit and performs two-dimensional scanning within a processing area set on the surface of the workpiece; a housing in which at least the laser light output unit and the laser light scanning unit are provided; an emission window unit formed in the housing and that emits the laser light that has been two-dimensionally scanned by the laser light scanning unit to the outside of the housing; a transparent member that is provided in the emission window unit and through which the laser light emitted from the emission window passes; and an imaging unit that images the workpiece through the emission window unit to generate a workpiece image including at least a part of the processing area, and that scans the laser light along a plane parallel to a processing reference plane that is located on the opposite side of the transparent member to the laser light scanning unit and extends parallel to the transparent member, based on position information based on the processing reference plane.

[0013] According to a first aspect of the present disclosure, the transparent member is made of a flat member that produces almost no lens effect (in other words, a flat member that has no lens effect or a low lens effect), and the imaging unit is arranged within the housing in an orientation in which its imaging optical axis is perpendicular to the processing reference surface.

[0014] According to this configuration, when the laser processing device processes a workpiece, the laser beam output unit emits a laser beam. The laser beam emitted from the laser beam output unit is irradiated onto the workpiece via the laser beam scanning unit and the exit window. By scanning the laser beam irradiated onto the workpiece, the workpiece can be processed.

[0015] Here, a predetermined machining area is set on the surface of the workpiece. By setting the machining area, it is possible to specify the part of the workpiece to be machined.

[0016] Furthermore, the laser light irradiated within the processing area is controlled based on position information based on a processing reference plane. This processing reference plane is set outside the housing and is set to extend parallel to the transparent member. By using the processing reference plane, for example, it is possible to easily form a common processing pattern on multiple workpieces of different heights. This makes it possible to suppress variations in processing accuracy, processing quality, etc. between workpieces.

[0017] According to the above configuration, the imaging unit is disposed within the housing with its imaging optical axis perpendicular to the machining reference surface. This arrangement allows the workpiece to be imaged directly above, rather than obliquely above. This eliminates distortion of the workpiece image captured. Furthermore, since the imaging optical axis of the imaging unit and the laser beam for machining do not necessarily need to be coaxial, the imaging field of view can be expanded.

[0018] However, when arranged as described above, the imaging unit images the workpiece through the transparent member. Therefore, there is a concern that the transparent member may distort the workpiece image. However, after extensive research, the inventors of the present application came up with the idea of ​​intentionally using a flat member that produces almost no lens effect (no lens effect or a low lens effect) as the transparent member.

[0019] In other words, by using a transparent member that generates almost no lens effect (no lens effect or a low lens effect), distortion of the workpiece image caused by the member is suppressed, thereby reducing the load on the control system.

[0020] Thus, according to the first aspect of the present disclosure, it is possible to widen the imaging field of view of the imaging unit while suppressing the load on the control system.

[0021] According to a second aspect of the present disclosure, the imaging optical axis may be configured to be non-coaxial with an optical axis of the laser light emitted from the emission window portion.

[0022] According to this configuration, the size of the imaging field of view is independent of the configuration of the scanning means, which is advantageous in widening the imaging field of view of the imaging unit.

[0023] Furthermore, according to a third aspect of the present disclosure, the imaging unit may be provided at a position where the laser light scanning unit is not included in its imaging field of view (in other words, positioned so as to exclude the laser light scanning unit from its imaging field of view).

[0024] According to this configuration, the laser beam scanning unit can be prevented from getting in the way when generating a workpiece image.

[0025] According to a fourth aspect of the present disclosure, the imaging section may be provided at a position where a part of an edge of the exit window is included in an imaging field of view of the imaging section.

[0026] Furthermore, according to a fifth aspect of the present disclosure, the laser processing device may include a display unit that displays a setting surface corresponding to the processing area, and the display unit may display a partial image of the workpiece image excluding part of the edge on the setting surface.

[0027] According to this configuration, a part of the edge of the exit window is reflected in the workpiece image generated by the imaging unit. By displaying a partial image in which the part of the edge is removed from the workpiece image, the usability of the laser processing device can be improved.

[0028] Furthermore, according to a sixth aspect of the present disclosure, the laser processing apparatus may include a scanning control unit that forms a predetermined processing pattern within the processing area by controlling the laser light scanning unit, and a processing block setting unit that sets a processing block including the processing pattern on the setting surface, and the processing block setting unit may correct the position of the processing block on the setting surface based on the partial image.

[0029] According to this configuration, the position of the processing block can be adjusted based on the partial image, thereby enabling more precise laser processing to be achieved.

[0030] According to a seventh aspect of the present disclosure, the imaging unit may be provided at a position where the imaging field of view includes the laser light scanning unit.

[0031] Furthermore, according to an eighth aspect of the present disclosure, the laser processing device may include a display unit that displays a setting surface corresponding to the processing area, and the display unit may display a partial image of the workpiece image excluding the laser light scanning unit on the setting surface.

[0032] According to this configuration, the laser beam scanning unit is reflected in the workpiece image generated by the imaging unit. By displaying a partial image of the workpiece image excluding the laser beam scanning unit, the usability of the laser processing device can be improved.

[0033] Furthermore, according to a ninth aspect of the present disclosure, the laser processing apparatus may include a scanning control unit that forms a predetermined processing pattern within the processing area by controlling the laser light scanning unit, and a processing block setting unit that sets a processing block including the processing pattern on the setting surface, and the processing block setting unit may correct the position of the processing block on the setting surface based on the partial image.

[0034] According to this configuration, the position of the processing block can be adjusted based on the partial image, thereby enabling more precise laser processing to be achieved.

[0035] Furthermore, according to a tenth aspect of the present disclosure, the laser light scanning unit may include a first scanner that scans the laser light emitted from the laser light output unit in a first direction, and a second scanner that scans the laser light scanned by the first scanner in a second direction that is approximately perpendicular to the first direction, and the imaging unit may be arranged closer to the second scanner than the first scanner.

[0036] This configuration allows the imaging unit and the second scanner to be placed close to each other, thereby reducing the misalignment between the imaging field of view of the imaging unit and the area actually irradiated with the laser light, and enabling more appropriate setting of the processing area, etc.

[0037] Furthermore, according to an eleventh aspect of the present disclosure, the laser processing apparatus may include a focus adjustment unit that is provided midway along the optical path from the laser light output unit to the laser light scanning unit and adjusts the focal position of the laser light emitted from the laser light output unit, and the first scanner, the second scanner, and the imaging unit may be arranged in that order along a direction perpendicular to an optical axis connecting the focus adjustment unit and the laser light scanning unit.

[0038] According to this configuration, the imaging unit and the second scanner can be brought closer together while keeping the laser light propagating from the focus adjustment unit to the laser light scanning unit as far away from the imaging unit as possible, thereby suppressing the deviation between the imaging field of view of the imaging unit and the area actually irradiated with the laser light, and enabling more appropriate setting of the processing area, etc.

[0039] According to a twelfth aspect of the present disclosure, the radius of curvature of the transparent member may be set within a range of 10,000 mm or more and 100,000 mm or less.

[0040] As a result of extensive research, the inventors of the present application have discovered that by setting the radius of curvature of the transparent member to 10,000 mm or more, distortion of the workpiece image caused by this transparent member can be kept within an acceptable range. [Effects of the Invention]

[0041] As described above, according to the laser processing device, it is possible to widen the imaging field of view of the imaging unit while suppressing the load on the control system. [Brief explanation of the drawings]

[0042] [Figure 1] FIG. 1 is a diagram illustrating an example of the overall configuration of a laser processing system. [Figure 2] FIG. 2 is a block diagram illustrating a schematic configuration of the laser processing device. [Figure 3A] FIG. 3A is a block diagram illustrating a schematic configuration of a marker head. [Figure 3B] FIG. 3B is a block diagram illustrating a schematic configuration of the marker head. [Figure 4] FIG. 4 is a perspective view illustrating an example of the appearance of the marker head. [Figure 5] FIG. 5 is a diagram illustrating the configuration of the laser light scanning unit. [Figure 6] FIG. 6 is a diagram illustrating the configuration of the laser light guide section, the laser light scanning section, and the distance measuring unit. [Figure 7] FIG. 7 is a cross-sectional view illustrating an example of an optical path connecting the laser light guide unit, the laser light scanning unit, and the distance measuring unit. [Figure 8] FIG. 8 is a perspective view illustrating an example of an optical path connecting the laser light guide unit, the laser light scanning unit, and the distance measuring unit. [Figure 9] FIG. 9 is a diagram illustrating the triangulation method. [Figure 10] FIG. 10 is a diagram illustrating the machining reference plane. [Figure 11] FIG. 11 is a bottom view illustrating the configuration of the transmission window and the wide-area camera. [Figure 12]FIG. 12 is a cross-sectional view illustrating the configuration of the transmission window and wide-area camera. [Figure 13] FIG. 13 is a vertical cross-sectional view illustrating the configuration of the transmission window and the wide-area camera. [Figure 14] FIG. 14 is a flowchart showing a method of using the laser processing system. [Figure 15] FIG. 15 is a flowchart illustrating a procedure for creating print settings. [Figure 16] FIG. 16 is a flowchart illustrating an example of an operation procedure of the laser processing device. [Figure 17] FIG. 17 is a diagram illustrating an example of the relationship between the machining area of ​​the workpiece and the setting surface on the display unit. [Figure 18] FIG. 18 is a diagram illustrating the generation of a partial image from a workpiece image. [Figure 19] FIG. 19 is a view corresponding to FIG. 10 and showing a modified example of the marker head. DETAILED DESCRIPTION OF THE INVENTION

[0043] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. Note that the following description is for illustrative purposes only.

[0044] That is, although this specification describes a laser marker as an example of a laser processing device, the technology disclosed herein can be applied to laser application equipment in general, regardless of whether it is called a laser processing device or a laser marker.

[0045] Furthermore, in this specification, printing processing will be described as a representative example of processing, but the present invention is not limited to printing processing and can be used in any processing using laser light, such as image marking.

[0046] <Overall structure> Fig. 1 is a diagram illustrating an example of the overall configuration of a laser processing system S, and Fig. 2 is a diagram illustrating an example of a schematic configuration of a laser processing device L in the laser processing system S. The laser processing system S illustrated in Fig. 1 includes the laser processing device L, and an operation terminal 800 and external device 900 connected thereto.

[0047] 1 and 2 performs processing by irradiating a workpiece W, which is a workpiece, with laser light emitted from a marker head 1 and performing three-dimensional scanning on the surface of the workpiece W. Note that "three-dimensional scanning" here refers to a general concept that combines a two-dimensional operation of scanning the surface of the workpiece W with the target of laser light (so-called "two-dimensional scanning") and a one-dimensional operation of adjusting the focal position of the laser light.

[0048] In particular, the laser processing device L according to this embodiment can emit laser light having a wavelength of around 1064 nm as laser light for processing the workpiece W. This wavelength corresponds to the wavelength range of near-infrared (NIR). Therefore, in the following description, the laser light for processing the workpiece W may be referred to as "near-infrared laser light" to distinguish it from other laser light. Of course, laser light having other wavelengths may also be used to process the workpiece W.

[0049] In addition, the laser processing apparatus L of this embodiment can measure the distance to the workpiece W via a distance measuring unit 5 built into the marker head 1, and can adjust the focal position of the near-infrared laser light using the measurement results.

[0050] As shown in FIGS. 1 and 2, the laser processing device L includes a marker head 1 for emitting laser light, and a marker controller 100 for controlling the marker head 1.

[0051] In this embodiment, the marker head 1 and the marker controller 100 are separate entities, electrically connected via electrical wiring, and optically coupled via an optical fiber cable.

[0052] More generally, one of the marker head 1 and the marker controller 100 can be integrated into the other, in which case optical fiber cables and the like can be omitted as appropriate.

[0053] The operation terminal 800 has, for example, a central processing unit (CPU) and a memory, and is connected to the marker controller 100. The operation terminal 800 functions as a terminal for setting various processing conditions such as print settings, and for displaying information related to laser processing to the user. The operation terminal 800 includes a display unit 801 for displaying information to the user, an operation unit 802 for accepting operation input by the user, and a storage device 803 for storing various information.

[0054] Specifically, the display unit 801 is configured with, for example, a liquid crystal display or an organic EL panel. The display unit 801 displays information related to laser processing, such as the operating status and processing conditions of the laser processing apparatus L. On the other hand, the operation unit 802 is configured with, for example, a keyboard and / or a pointing device. Here, the pointing device includes a mouse and / or a joystick. The operation unit 802 is configured to accept operation input by the user, and is used to operate the marker head 1 via the marker controller 100.

[0055] The operation terminal 800 configured as described above can set processing conditions for laser processing based on operation input by the user. These processing conditions include, for example, the content (marking pattern) of the character string, figure, etc. to be printed on the workpiece W, the output (target output) required for the laser beam, and the scanning speed (scan speed) of the laser beam on the workpiece W.

[0056] The processing conditions according to this embodiment also include conditions and parameters (hereinafter also referred to as "distance measurement conditions") related to the aforementioned distance measurement unit 5. Such distance measurement conditions include, for example, data relating a signal indicating the detection result by the distance measurement unit 5 to the distance to the surface of the workpiece W.

[0057] The processing conditions set by the operation terminal 800 are output to the marker controller 100 and stored in the condition setting storage unit 102. If necessary, the storage device 803 in the operation terminal 800 may store the processing conditions.

[0058] The operation terminal 800 can be integrated into, for example, the marker controller 100. In this case, the term "control unit" or the like is used instead of "operation terminal." However, at least in this embodiment, the operation terminal 800 and the marker controller 100 are separate entities.

[0059] The external device 900 is connected, as necessary, to the marker controller 100 of the laser processing device L. In the example shown in Fig. 1, an image recognition device 901 and a programmable logic controller (PLC) 902 are provided as the external device 900.

[0060] Specifically, the image recognition device 901 determines, for example, the type and position of a workpiece W being transported on a production line. For example, an image sensor can be used as the image recognition device 901. The PLC 902 is used to control the laser processing system S in accordance with a predetermined sequence.

[0061] In addition to the above-mentioned devices and equipment, the laser processing apparatus L can also be connected to devices for operation and control, computers for performing various other processes, storage devices, peripheral devices, etc. In this case, the connection may be, for example, a serial connection such as IEEE1394, RS-232, RS-422, or USB, or a parallel connection. Alternatively, an electrical, magnetic, or optical connection via a network such as 10BASE-T, 100BASE-TX, or 1000BASE-T may be adopted. In addition to a wired connection, a wireless connection using a wireless LAN such as IEEE802, or radio waves, infrared rays, optical communications, etc. such as Bluetooth (registered trademark) may also be used. Furthermore, various memory cards, magnetic disks, magneto-optical disks, semiconductor memories, hard disks, etc. may be used as storage media for data exchange, saving various settings, etc.

[0062] Below, the hardware configurations of the marker controller 100 and the marker head 1 will be described, and the configuration related to the control of the marker head 1 by the marker controller 100 will be described in that order.

[0063] <Marker Controller 100> As shown in Figure 2, the marker controller 100 includes a condition setting memory unit 102 that stores the above-mentioned processing conditions, a control unit 101 that controls the marker head 1 based on the processing conditions stored therein, and an excitation light generation unit 110 that generates laser excitation light (excitation light).

[0064] (Condition setting storage unit 102) The condition setting storage unit 102 is configured to store the processing conditions set via the operation terminal 800, and to output the stored processing conditions to the control unit 101 as necessary.

[0065] Specifically, the condition setting storage unit 102 is configured using a volatile memory, a non-volatile memory, a hard disk drive (HDD), a solid state drive (SSD), etc., and can temporarily or continuously store information indicating the processing conditions. Note that, when the operation terminal 800 is incorporated into the marker controller 100, the storage device 803 can be configured to also function as the condition setting storage unit 102.

[0066] (Control unit 101) The control unit 101 performs printing processing, etc. on the workpiece W by controlling at least the excitation light generating unit 110 in the marker controller 100, as well as the laser light output unit 2, laser light guide unit 3, laser light scanning unit 4, ranging unit 5, and wide-area camera 6 described below in the marker head 1 based on the processing conditions stored in the condition setting memory unit 102.

[0067] Specifically, the control unit 101 has a CPU, memory, and input / output bus, and generates a control signal based on a signal indicating information input via the operation terminal 800 and a signal indicating processing conditions read from the condition setting storage unit 102. The control unit 101 outputs the generated control signal to each unit of the laser processing device L, thereby controlling the printing processing on the workpiece W and the measurement of the distance to the workpiece W.

[0068] For example, when starting to process the workpiece W, the control unit 101 reads the target output stored in the condition setting memory unit 102, and outputs a control signal generated based on the target output to the excitation light source drive unit 112, thereby controlling the generation of laser excitation light.

[0069] Furthermore, when actually processing the workpiece W, the control unit 101 reads, for example, a processing pattern (marking pattern) stored in the condition setting storage unit 102, and outputs a control signal generated based on the processing pattern to the laser light scanning unit 4, thereby performing two-dimensional scanning with the near-infrared laser light. In that it controls two-dimensional scanning of the near-infrared laser light, the control unit 101 exemplifies the "scanning control unit" in this embodiment.

[0070] (Excitation light generation unit 110) The pumping light generating unit 110 includes a pumping light source 111 that generates laser light according to a drive current, a pumping light source driving unit 112 that supplies a drive current to the pumping light source 111, and a pumping light collecting unit 113 that is optically coupled to the pumping light source 111. The pumping light source 111 and the pumping light collecting unit 113 are fixed inside a pumping casing (not shown). Although details are omitted, this pumping casing is made of a metal such as copper that has excellent thermal conductivity, and can efficiently dissipate heat from the pumping light source 111.

[0071] Each part of the pump light generating section 110 will be explained in turn below.

[0072] The pumping light source driver 112 supplies a drive current to the pumping light source 111 based on a control signal output from the controller 101. Although details are omitted, the pumping light source driver 112 determines a drive current based on the target output determined by the controller 101, and supplies the determined drive current to the pumping light source 111.

[0073] The pumping light source 111 receives a drive current from the pumping light source driver 112 and emits laser light in accordance with the drive current. For example, the pumping light source 111 is configured with a laser diode (LD) or the like, and an LD array or LD bar in which a plurality of LD elements are arranged in a line can be used. When an LD array or LD bar is used as the pumping light source 111, the laser light emitted from each element is output in a line shape and enters the pumping light focusing unit 113.

[0074] The excitation light focusing unit 113 focuses the laser light output from the excitation light source 111 and outputs it as laser excitation light (excitation light). For example, the excitation light focusing unit 113 is composed of a focusing lens or the like, and has an incident surface onto which the laser light is incident and an exit surface from which the laser excitation light is output. The excitation light focusing unit 113 is optically coupled to the marker head 1 via the above-mentioned optical fiber cable. Therefore, the laser excitation light output from the excitation light focusing unit 113 is guided to the marker head 1 via the optical fiber cable.

[0075] The pumping light generating unit 110 can be an LD unit or LD module in which the pumping light source driving unit 112, the pumping light source 111, and the pumping light collecting unit 113 are pre-assembled. The pumping light emitted from the pumping light generating unit 110 (specifically, the laser pumping light output from the pumping light collecting unit 113) can be unpolarized, which eliminates the need to consider changes in the polarization state and is advantageous in terms of design. In particular, with regard to the configuration around the pumping light source 111, it is preferable that the LD unit itself, which bundles and outputs light obtained from an LD array in which several tens of LD elements are arranged, via an optical fiber, is provided with a mechanism for unpolarizing the output light.

[0076] (Other components) The marker controller 100 also has a distance measurement unit 103 that measures the distance to the workpiece W via the distance measurement unit 5. The distance measurement unit 103 is electrically connected to the distance measurement unit 5 and is capable of receiving a signal related to the measurement result by the distance measurement unit 5 (at least a signal indicating the reception position of the distance measurement light in the distance measurement light receiving unit 5B).

[0077] As will be described later, the laser processing device L according to this embodiment is equipped with a narrow area camera 37 and a wide area camera 6 for capturing images of the surface of the workpiece W. The control unit 101 in the marker controller 100 can perform processing based on the images captured by the narrow area camera 37 or the wide area camera 6.

[0078] The marker controller 100 also includes a setting unit 107 that sets information related to the marking pattern. The settings in the setting unit 107 are read and used by the control unit 101, which functions as a scan control unit.

[0079] Note that distance measurement section 103 and setting section 107 may be configured by control section 101. For example, control section 101 may also function as distance measurement section 103.

[0080] The distance measurement unit 103 and the setting unit 107 will be described in detail later.

[0081] <Marker head 1> As described above, the laser excitation light generated by the excitation light generation unit 110 is guided to the marker head 1 via an optical fiber cable. This marker head 1 is equipped with a laser light output unit 2 that amplifies and generates laser light based on the laser excitation light and outputs it, a laser light scanning unit 4 that irradiates the surface of the workpiece W with the laser light output from the laser light output unit 2 to perform two-dimensional scanning, a laser light guide unit 3 that forms an optical path from the laser light output unit 2 to the laser light scanning unit 4, and a distance measurement unit 5 that measures the distance to the surface of the workpiece W based on the distance measurement light projected and received via the laser light scanning unit 4.

[0082] Here, the laser light guide unit 3 in this embodiment not only constitutes an optical path, but also comprises a combination of multiple components, such as a Z scanner (focus adjustment unit) 33 that adjusts the focal position of the laser light, a guide light source that emits guide light, and a narrow-area camera 37 that images the surface of the workpiece W.

[0083] In addition, the laser light guide unit 3 further has an upstream merging mechanism 31 that merges the near-infrared laser light output from the laser light output unit 2 and the guide light emitted from the guide light source 36, and a downstream merging mechanism 35 that merges the laser light guided to the laser light scanning unit 4 and the distance measuring light projected from the distance measuring unit 5.

[0084] 3A and 3B are block diagrams illustrating an example of the schematic configuration of the marker head 1, and Fig. 4 is a perspective view illustrating an example of the appearance of the marker head 1. Of Figs. 3A and 3B, Fig. 3A illustrates an example of processing a workpiece W using near-infrared laser light, and Fig. 3B illustrates an example of measuring the distance to the surface of the workpiece W using a distance measuring unit 5.

[0085] As illustrated in FIGS. 3A to 4, the marker head 1 includes a housing 10 in which at least a laser light output unit 2, a laser light guide unit 3, a laser light scanning unit 4, and a distance measurement unit 5 are provided. The housing 10 has a substantially rectangular parallelepiped outer shape as shown in FIG. 4. The lower surface of the housing 10 is defined by a plate-shaped bottom plate 10a. The bottom plate 10a is provided with a transmission window 19 as a transmission window portion for emitting laser light from the marker head 1 to the outside of the marker head 1. The transmission window 19 is formed by fitting a plate-shaped transparent member 19b, which is capable of transmitting near-infrared laser light, guide light, and distance measurement light, into a through-hole 19a that passes through the bottom plate 10a in the plate thickness direction.

[0086] In the following description, the longitudinal direction of the housing 10 in Fig. 4 may be simply referred to as the "longitudinal direction" or "front-rear direction," and the lateral direction of the housing 10 in Fig. 4 may be simply referred to as the "lateral direction" or "left-right direction." Similarly, the height direction of the housing 10 in Fig. 4 may be simply referred to as the "height direction" or "up-down direction."

[0087] Fig. 5 is a perspective view illustrating the configuration of the laser light scanning unit 4. Fig. 6 is a cross-sectional view illustrating the configurations of the laser light guide unit 3, the laser light scanning unit 4, and the distance measuring unit 5, Fig. 7 is a cross-sectional view illustrating the optical path connecting the laser light guide unit 3, the laser light scanning unit 4, and the distance measuring unit 5, and Fig. 8 is a perspective view illustrating the optical path connecting the laser light guide unit 3, the laser light scanning unit 4, and the distance measuring unit 5.

[0088] 5 and 6, a partition 11 is provided inside the housing 10. The interior space of the housing 10 is divided into one side and the other side in the longitudinal direction by this partition 11.

[0089] Specifically, the partition 11 is formed in a flat plate shape extending in a direction perpendicular to the longitudinal direction of the housing 10. Furthermore, in the longitudinal direction of the housing 10, the partition 11 is disposed closer to one side in the longitudinal direction (the front side in FIG. 4) than the center of the housing 10 in the same direction.

[0090] Therefore, the space partitioned on one side in the longitudinal direction within housing 10 has a shorter longitudinal dimension than the space partitioned on the other side in the longitudinal direction (the rear side in FIG. 4). Hereinafter, the space partitioned on the other side in the longitudinal direction within housing 10 will be referred to as a first space S1, while the space partitioned on the one side in the longitudinal direction will be referred to as a second space S2.

[0091] In this embodiment, the first space S1 contains the laser light output unit 2, some components of the laser light guide unit 3, the laser light scanning unit 4, and the distance measuring unit 5. The second space S2 contains the main components of the laser light guide unit 3.

[0092] More specifically, the first space S1 is partitioned into a space on one side (left side in FIG. 4) in the short side direction and a space on the other side (right side in FIG. 4) by a substantially flat base plate 12. In the former space, mainly components constituting the laser light output unit 2 are arranged.

[0093] More specifically, among the components that make up the laser light output unit 2, optical components 21 such as optical lenses and optical crystals that need to be sealed as airtight as possible are arranged inside a storage space surrounded by a base plate 12, etc., in the space on one side of the short side of the first space S1.

[0094] On the other hand, among the components constituting the laser light output unit 2, components that do not necessarily need to be sealed, such as electrical wiring and the heat sink 22 shown in FIG. 5, are arranged on the opposite side of the base plate 12 from the optical component 21 (the other side in the short direction in the first space S1).

[0095] 5 and 6, the laser light scanning unit 4 can be arranged on one side in the short direction across the base plate 12, similar to the optical component 21 in the laser light output unit 2. Specifically, the laser light scanning unit 4 according to this embodiment is adjacent to the partition 11 in the longitudinal direction, and is arranged along the inner bottom surface of the housing 10 in the up-down direction.

[0096] 6, the distance measuring unit 5 is arranged in the space on the other side in the short side direction of the first space S1, similar to the heat sink 22 in the laser light output section 2.

[0097] Furthermore, the components constituting the laser beam guide unit 3 are mainly arranged in the second space S2. In this embodiment, most of the components constituting the laser beam guide unit 3 are housed in a space surrounded by the partition 11 and the cover member 17 that defines the front surface of the housing 10.

[0098] Among the components constituting the laser light guide unit 3, the downstream merging mechanism 35 is disposed in a portion near the partition 11 in the first space S1 (see FIG. 5). That is, in this embodiment, the downstream merging mechanism 35 is located near the boundary between the first space S1 and the second space S2.

[0099] Further, a through-hole (not shown) is formed in the base plate 12, penetrating the base plate 12 in the thickness direction. The laser light guide unit 3 and the laser light scanning unit 4 are optically coupled to the distance measuring unit 5 through this through-hole.

[0100] The configurations of the laser light output unit 2, the laser light guide unit 3, the laser light scanning unit 4, and the distance measuring unit 5 will be described in order below.

[0101] (Laser light output unit 2) The laser light output unit 2 is configured to generate near-infrared laser light for printing processing based on the laser excitation light generated by the excitation light generation unit 110, and to output the near-infrared laser light to the laser light guide unit 3.

[0102] Specifically, the laser light output unit 2 includes a laser oscillator 21a that generates laser light having a predetermined wavelength based on laser excitation light and amplifies the generated laser light to emit near-infrared laser light, a beam sampler 21b that separates a portion of the near-infrared laser light emitted from the laser oscillator 21a, and a power monitor 21c onto which the near-infrared laser light separated by the beam sampler 21b is incident.

[0103] Although details are omitted, the laser oscillator 21a according to this embodiment has a laser medium that emits laser light by performing stimulated emission corresponding to laser excitation light, a Q switch that pulses the laser light emitted from the laser medium, and a mirror that resonates the laser light pulsed by the Q switch.

[0104] In particular, in this embodiment, a rod-shaped Nd:YVO4 (yttrium vanadate) is used as the laser medium. This allows the laser oscillator 21a to emit laser light having a wavelength around 1064 nm (the near-infrared laser light mentioned above). However, this is not the only example, and other laser media such as rare-earth doped YAG, YLF, GdVO4, etc. can also be used. Various solid-state laser media can be used depending on the application of the laser processing device L.

[0105] In addition, a wavelength conversion element can be combined with a solid-state laser medium to convert the wavelength of the output laser light to any wavelength. Also, a so-called fiber laser, which uses a fiber as an oscillator instead of a bulk solid-state laser medium, may be used.

[0106] Furthermore, the laser oscillator 21a may be configured by combining a solid-state laser medium such as Nd:YVO4 with a fiber. In this case, as when a solid-state laser medium is used, a laser with a short pulse width is emitted to suppress thermal damage to the workpiece W, while as when a fiber is used, high output is realized to achieve faster printing processing.

[0107] The power monitor 21c detects the output of the near-infrared laser light. The power monitor 21c is electrically connected to the marker controller 100, and can output the detection signal to the control unit 101 and the like.

[0108] (Laser light guide unit 3) The laser beam guide unit 3 forms an optical path P that guides the near-infrared laser beam emitted from the laser beam output unit 2 to the laser beam scanning unit 4. In addition to a bend mirror 34 for forming the optical path P, the laser beam guide unit 3 also includes a Z scanner (focus adjustment unit) 33, a guide light source (guide beam emission unit) 36, and a narrow-area camera 37. All of these components are provided inside the housing 10 (mainly in the second space S2).

[0109] The near-infrared laser light incident from the laser light output unit 2 is reflected by the bend mirror 34 and passes through the laser light guide unit 3. On the way to the bend mirror 34, a Z scanner 33 is disposed to adjust the focal position of the near-infrared laser light. The near-infrared laser light passes through the Z scanner 33 and is reflected by the bend mirror 34, and then enters the laser light scanning unit 4.

[0110] The optical path P formed by the laser beam guide unit 3 can be divided into two parts at the Z scanner 33 serving as a focus adjustment unit. In detail, the optical path P formed by the laser beam guide unit 3 can be divided into an upstream optical path Pu from the laser beam output unit 2 to the Z scanner 33, and a downstream optical path Pd from the Z scanner 33 to the laser beam scanning unit 4.

[0111] More specifically, the upstream optical path Pu is provided inside the housing 10, and extends from the laser light output unit 2 to the Z scanner 33 via the upstream merging mechanism 31 described above.

[0112] On the other hand, the downstream optical path Pd is provided inside the housing 10 and extends from the Z scanner 33, through the bend mirror 34 and the aforementioned downstream merging mechanism 35 in that order, to the first scanner 41 in the laser light scanning unit 4.

[0113] Thus, inside the housing 10, the upstream merging mechanism 31 is provided midway along the upstream optical path Pu, and the downstream merging mechanism 35 is provided midway along the downstream optical path Pd.

[0114] The configuration related to the laser light guide unit 3 will be described below in order.

[0115] -Guide Light Source 36- The guide light source 36 is provided in the second space S2 inside the housing 10, and emits guide light for projecting a predetermined processing pattern onto the surface of the workpiece W. The wavelength of this guide light is set to fall within the visible light range. As an example, the guide light source 36 according to this embodiment emits red laser light having a wavelength around 655 nm as the guide light. Therefore, when the guide light is emitted from the marker head 1, the user can visually recognize the guide light.

[0116] In this embodiment, the wavelength of the guide light is set to be different from at least the wavelength of the near-infrared laser light. As will be described later, the distance measurement light emitting section 5A in the distance measurement unit 5 emits distance measurement light having a wavelength different from the guide light and the near-infrared laser light. Therefore, the distance measurement light, the guide light, and the laser light have wavelengths different from each other.

[0117] Specifically, the guide light source 36 is disposed at approximately the same height as the upstream merging mechanism 31 in the second space S2, and can emit a visible laser light (guide light) toward the inside in the short-side direction of the housing 10. The guide light source 36 is also oriented such that the optical axis of the guide light emitted from the guide light source 36 intersects with the upstream merging mechanism 31.

[0118] Note that "substantially the same height" here means that the height positions are substantially the same when viewed from the bottom plate 10a that forms the underside of the housing 10. In other descriptions, it also refers to the height when viewed from the bottom plate 10a.

[0119] Therefore, for example, when a guide light is emitted from the guide light source 36 to allow a user to visually recognize a processing pattern formed by the near-infrared laser light, the guide light reaches the upstream merging mechanism 31. The upstream merging mechanism 31 has a dichroic mirror (not shown) as an optical component. As will be described later, this dichroic mirror transmits the guide light while reflecting the near-infrared laser light. As a result, the guide light transmitted through the dichroic mirror and the near-infrared laser light reflected by the mirror merge and become coaxial.

[0120] The guide light source 36 according to this embodiment is configured to emit guide light based on a control signal output from the control unit 101.

[0121] -Upstream merging mechanism 31- The upstream merging mechanism 31 merges the guide light emitted from the guide light source 36 serving as a guide light emitting section into the upstream optical path Pu. By providing the upstream merging mechanism 31, the guide light emitted from the guide light source 36 and the near-infrared laser light in the upstream optical path Pu can be made coaxial.

[0122] As described above, the wavelength of the guide light is set to be different from at least the wavelength of the near-infrared laser light. Therefore, as described above, the upstream merging mechanism 31 can be configured using, for example, a dichroic mirror. The near-infrared laser light and the guide light, which have been made coaxial by the dichroic mirror, propagate downward, pass through the Z scanner 33, and reach the bend mirror 34.

[0123] -Z Scanner 33- The Z scanner 33 as a focal point adjustment unit is disposed midway along the optical path formed by the laser light guide unit 3, and can adjust the focal point position of the near-infrared laser light emitted from the laser light output unit 2.

[0124] In detail, as shown in Figures 3A to 3B, the Z scanner 33 of this embodiment has an incident lens 33a that transmits the near-infrared laser light emitted from the laser light output unit 2, a collimating lens 33b that passes the near-infrared laser light that has passed through the incident lens 33a, an exit lens 33c that passes the near-infrared laser light that has passed through the incident lens 33a and the collimating lens 33b, a lens driving unit 33d that moves the incident lens 33a, and a casing 33e that houses the incident lens 33a, the collimating lens 33b, and the exit lens 33c.

[0125] The entrance lens 33a is a plano-concave lens, and the collimator lens 33b and the exit lens 33c are plano-convex lenses. The entrance lens 33a, the collimator lens 33b, and the exit lens 33c are arranged so that their optical axes are coaxial with each other.

[0126] Furthermore, in the Z scanner 33, the lens driving unit 33d moves the incident lens 33a along the optical axis. This makes it possible to change the relative distance between the incident lens 33a and the exit lens 33c while keeping the optical axes of the incident lens 33a, collimator lens 33b, and exit lens 33c coaxial with respect to the near-infrared laser light passing through the Z scanner 33. This changes the focal position of the near-infrared laser light irradiated onto the workpiece W.

[0127] Each component of the Z scanner 33 will be described in more detail below.

[0128] Casing 33e has a substantially cylindrical shape. As shown in Figures 3A and 3B, openings 33f are formed at both ends of casing 33e to allow near-infrared laser light to pass through. Inside casing 33e, entrance lens 33a, collimator lens 33b, and exit lens 33c are arranged vertically in this order.

[0129] Of the entrance lens 33a, collimator lens 33b, and exit lens 33c, the collimator lens 33b and the exit lens 33c are fixed inside a casing 33e. Meanwhile, the entrance lens 33a is provided so as to be movable in the vertical direction. The lens driver 33d has, for example, a motor, and moves the entrance lens 33a in the vertical direction. This changes the relative distance between the entrance lens 33a and the exit lens 33c.

[0130] For example, suppose that the distance between the entrance lens 33a and the exit lens 33c is adjusted to be relatively short by the lens driving unit 33d. In this case, the convergence angle of the near-infrared laser light passing through the exit lens 33c becomes relatively small, and the focal position of the near-infrared laser light becomes farther away from the transmission window 19 of the marker head 1.

[0131] On the other hand, it is assumed that the distance between the entrance lens 33a and the exit lens 33c is adjusted to be relatively long by the lens driving unit 33d. In this case, the convergence angle of the near-infrared laser light passing through the exit lens 33c becomes relatively large, and the focal position of the near-infrared laser light approaches the transmission window 19 of the marker head 1.

[0132] In the Z scanner 33, among the entrance lens 33a, collimator lens 33b, and exit lens 33c, the entrance lens 33a may be fixed inside the casing 33e, and the collimator lens 33b and exit lens 33c may be made movable in the vertical direction. Alternatively, the entrance lens 33a, collimator lens 33b, and exit lens 33c may all be made movable in the vertical direction.

[0133] In this way, the Z scanner 33 as a focus adjustment unit functions as a means for scanning the near-infrared laser light in the vertical direction. Hereinafter, the scanning direction by the Z scanner 33 may be referred to as the "Z direction."

[0134] As described above, the near-infrared laser light passing through the Z scanner 33 is coaxial with the guide light emitted from the guide light source 36. Therefore, by operating the Z scanner 33, the focal position of not only the near-infrared laser light but also the guide light can be adjusted.

[0135] The Z scanner 33 according to this embodiment, particularly the lens driving unit 33d in the Z scanner 33, is configured to operate based on a control signal output from the control unit 101.

[0136] -Narrow Area Camera 37- In this embodiment, the narrow area camera 37 is disposed at approximately the same height as the bend mirror 34, and receives reflected light incident from the laser light scanning unit 4 to the laser light guide unit 3. The narrow area camera 37 according to this embodiment is configured so that reflected light reflected at the printing point on the workpiece W enters the narrow area camera 37 via the bend mirror 34. The narrow area camera 37 can capture an image of the surface of the workpiece W by focusing the reflected light thus incident. The layout of the narrow area camera 37 can be changed as appropriate. For example, the heights of the narrow area camera 37 and the bend mirror 34 may be different from each other.

[0137] The reflected light used for imaging by the narrow-area camera 37 propagates along the aforementioned downstream optical path Pd. Therefore, by appropriately operating the laser beam scanning unit 4, it is possible to scan the processing area R1 illustrated in FIG.

[0138] The narrow-area camera 37 according to this embodiment is configured to operate based on a control signal output from the control unit 101, similar to the guide light source 36 and the like.

[0139] -Bend Mirror 34- The bend mirror 34 is provided midway along the downstream optical path Pd and is arranged to bend the optical path Pd and direct it backward. As shown in Fig. 6, the bend mirror 34 is arranged at approximately the same height as the dichroic mirror 35a in the downstream merging mechanism 35, and can reflect the near-infrared laser light and the guide light that have passed through the Z scanner 33.

[0140] The near-infrared laser light and the guide light reflected by the bend mirror 34 propagate backward, pass through the downstream merging mechanism 35, and reach the laser light scanning unit (specifically, the first scanner 41) 4.

[0141] -Downstream merging mechanism 35- The downstream merging mechanism 35 merges the distance measurement light emitted from the distance measurement light emitting portion 5A in the distance measurement unit 5 with the aforementioned downstream optical path Pd, thereby guiding the light to the workpiece W via the laser light scanning portion 4. In addition, the downstream merging mechanism 35 guides the distance measurement light, which is reflected by the workpiece W and returns to the laser light scanning portion 4 and the downstream optical path Pd in ​​this order, to the distance measurement light receiving portion 5B in the distance measurement unit 5.

[0142] By providing the downstream merging mechanism 35, the distance measurement light emitted from the distance measurement light emitting unit 5A can be made coaxial with the near-infrared laser light and guide light on the downstream optical path Pd. At the same time, by providing the downstream merging mechanism 35, the distance measurement light that is emitted from the marker head 1 and reflected by the workpiece W and that enters the marker head 1 can be guided to the distance measurement light receiving unit 5B.

[0143] As described above, the wavelength of the distance measurement light is set to be different from the wavelengths of the near-infrared laser light and the guide light. Therefore, the downstream-side merging mechanism 35 can be configured using, for example, a dichroic mirror, similar to the upstream-side merging mechanism 31.

[0144] Specifically, the downstream merging mechanism 35 according to this embodiment has a dichroic mirror 35a that transmits one of the distance measurement light and the guide light and reflects the other (see FIGS. 6 and 7). More specifically, the dichroic mirror 35a is disposed at approximately the same height as the bend mirror 34 and behind the bend mirror 34, in the space on the left side in the short direction within the housing 10.

[0145] 6 and other figures, the dichroic mirror 35a is fixed in a position in which one mirror surface faces the bend mirror 34 and the other mirror surface faces the base plate 12. Therefore, the near-infrared laser light and the guide light are incident on one mirror surface of the dichroic mirror 35a, while the distance measurement light is incident on the other mirror surface.

[0146] The dichroic mirror 35a according to this embodiment reflects the distance measurement light and transmits the near-infrared laser light and the guide light. Thus, when the distance measurement light emitted from the distance measurement unit 5 is incident on the dichroic mirror 35a, the distance measurement light can be merged into the downstream optical path Pd and made coaxial with the near-infrared laser light and the guide light. The coaxially aligned near-infrared laser light, guide light, and distance measurement light then reach the first scanner 41, as shown in FIGS. 3A and 3B.

[0147] On the other hand, the distance measurement light reflected by the workpiece W reaches the downstream optical path Pd by returning to the laser light scanning unit 4. The distance measurement light that has returned to the downstream optical path Pd is reflected by the dichroic mirror 35a in the downstream merging mechanism 35 and reaches the distance measurement unit 5.

[0148] As shown in Figure 7, the distance measurement light incident on the dichroic mirror 35a from the distance measurement unit 5 and the distance measurement light reflected by the dichroic mirror 35a and incident on the distance measurement unit 5 both propagate along the left-right direction (the short side direction of the housing 10) when the housing 10 is viewed in a plane.

[0149] (Laser light scanning unit 4) As shown in Figure 3A, the laser light scanning unit 4 is configured to irradiate the workpiece W with laser light (near-infrared laser light) emitted from the laser light output unit 2 and guided by the laser light guide unit 3, and to perform two-dimensional scanning on the surface of the workpiece W.

[0150] 5, the laser beam scanning unit 4 is configured as a so-called two-axis galvanometer scanner. That is, the laser beam scanning unit 4 has a first scanner 41 for scanning the near-infrared laser beam incident from the laser beam guide unit 3 in a first direction, and a second scanner 42 for scanning the near-infrared laser beam scanned by the first scanner 41 in a second direction.

[0151] Here, the second direction refers to a direction that is approximately perpendicular to the first direction. Therefore, the second scanner 42 can scan the near-infrared laser light in a direction that is approximately perpendicular to the first scanner 41. In this embodiment, the first direction is equal to the front-to-rear direction (the longitudinal direction of the housing 10), and the second direction is equal to the left-to-right direction (the lateral direction of the housing 10). Hereinafter, the first direction will be referred to as the "X direction," and the second direction that is perpendicular to the first direction will be referred to as the "Y direction." Both the X direction and the Y direction are perpendicular to the Z direction described above.

[0152] The first scanner 41 has a first mirror 41a at its tip. The first mirror 41a is disposed at approximately the same height as the bend mirror 34 and the dichroic mirror 35a and behind the dichroic mirror 35a. Therefore, as shown in Fig. 5, the bend mirror 34, the dichroic mirror 35a, and the first mirror 41a are aligned in a line along the front-to-rear direction (the longitudinal direction of the housing 10).

[0153] The first mirror 41a is also rotationally driven by a motor (not shown) built into the first scanner 41. This motor can rotate the first mirror 41a around a rotation axis extending in the vertical direction. By adjusting the rotational attitude of the first mirror 41a, it is possible to adjust the reflection angle of the near-infrared laser light by the first mirror 41a.

[0154] Similarly, the second scanner 42 has a second mirror 42a at its tip. The second mirror 42a is disposed at approximately the same height as the first mirror 41a of the first scanner 41 and to the right of the first mirror 41a. Therefore, as shown in Fig. 6, the first mirror 41a and the second mirror 42a are aligned in the left-right direction (the short-side direction of the housing 10).

[0155] The second mirror 42a is also rotationally driven by a motor (not shown) built into the second scanner 42. This motor can rotate the second mirror 42a around a rotation axis extending in the front-to-rear direction. By adjusting the rotational attitude of the second mirror 42a, it is possible to adjust the reflection angle of the near-infrared laser light by the second mirror 42a.

[0156] Therefore, when near-infrared laser light enters the laser light scanning unit 4 from the downstream merging mechanism 35, the near-infrared laser light is reflected in sequence by the first mirror 41a in the first scanner 41 and the second mirror 42a in the second scanner 42, and is emitted outside the marker head 1 through the transparent window 19.

[0157] At this time, by operating the motor of the first scanner 41 and adjusting the rotational attitude of the first mirror 41a, it becomes possible to scan the near-infrared laser light in a first direction on the surface of the workpiece W. At the same time, by operating the motor of the second scanner 42 and adjusting the rotational attitude of the second mirror 42a, it becomes possible to scan the near-infrared laser light in a second direction on the surface of the workpiece W.

[0158] As described above, not only the near-infrared laser light but also the guide light that has passed through the dichroic mirror 35a of the downstream merging mechanism 35 or the distance measurement light that has been reflected by the mirror 35a is incident on the laser light scanning unit 4. The laser light scanning unit 4 according to this embodiment can perform two-dimensional scanning of the incident guide light or distance measurement light by operating the first scanner 41 and the second scanner 42, respectively.

[0159] The rotational positions that the first mirror 41a and the second mirror 42a can take are basically set within a range such that when the near-infrared laser light is reflected by the second mirror 42a, the reflected light passes through the transmission window 19 (see also Figures 7 and 8).

[0160] In this way, the laser light scanning unit 4 of this embodiment is electrically controlled by the control unit 101 as a scanning control unit, and can irradiate near-infrared laser light onto a predetermined processing area R1 to form a predetermined processing pattern (marking pattern) within the same area R1, as illustrated in Figure 10.

[0161] (Range measurement unit 5) 3B, the distance measuring unit 5 projects distance measuring light via the laser light scanning unit 4 and irradiates the light onto the surface of the workpiece W. The distance measuring unit 5 also receives the distance measuring light reflected by the surface of the workpiece W via the laser light scanning unit 4.

[0162] The distance measuring unit 5 is broadly divided into a module for projecting distance measuring light and a module for receiving distance measuring light. Specifically, the distance measuring unit 5 is provided inside the housing 10 and includes a distance measuring light emitting section 5A that emits distance measuring light to the laser light scanning section 4 to measure the distance from the marker head 1 in the laser processing device L to the surface of the workpiece W. The distance measuring unit 5 also includes a distance measuring light receiving section 5B that is provided inside the housing 10 and receives, via the laser light scanning section 4, the distance measuring light that is emitted from the distance measuring light emitting section 5A and reflected by the workpiece W.

[0163] Furthermore, the distance measurement unit 5 is provided with a support base 50 that supports the distance measurement light emitting portion 5A and the distance measurement light receiving portion 5B from below, and is fixed inside the housing 10 via this support base 50.

[0164] As described above, the distance measurement unit 5 is provided in the space on the other side of the first space S1 in the short direction. As shown in Fig. 7, the distance measurement unit 5 emits distance measurement light forward along the longitudinal direction of the housing 10, and receives distance measurement light propagating substantially backward along the same longitudinal direction.

[0165] The distance measuring unit 5 is optically coupled to the laser light guide unit 3 via the dichroic mirror 35a. As described above, the distance measuring unit 5 projects distance measuring light along the longitudinal direction of the housing 10. In contrast, the dichroic mirror 35a reflects distance measuring light propagating along the lateral direction of the housing 10, rather than along the longitudinal direction.

[0166] Therefore, in order to configure an optical path connecting the distance measurement unit 5 and the dichroic mirror 35a, a bend mirror 59 is provided inside the housing 10 (see FIGS. 6 and 7).

[0167] Therefore, the distance measurement light incident on the bend mirror 59 from the distance measurement light emitting unit 5A is reflected by the mirror 59 and then incident on the dichroic mirror 35a. On the other hand, the distance measurement light returned to the laser light scanning unit 4 and reflected by the dichroic mirror 35a is incident on the bend mirror 59 and is then reflected by the mirror 59 and incident on the distance measurement light receiving unit 5B.

[0168] The configuration of each part of the distance measurement unit 5 will be explained in order below.

[0169] -Distance measurement light emitting part 5A- The distance measurement light emitting unit 5A is provided inside the housing 10, and is configured to emit distance measurement light for measuring the distance from the marker head 1 in the laser processing device L to the surface of the workpiece W.

[0170] Specifically, the distance measurement light emitting unit 5A has the distance measurement light source 51 and the light projecting lens 52 described above, a casing 53 that houses these, and a pair of guide plates 54L, 54R that guide the distance measurement light focused by the light projecting lens 52. The distance measurement light source 51, the light projecting lens 52, and the guide plates 54L, 54R are lined up in order from the rear side of the housing 10, and the direction in which they are lined up is substantially the same as the longitudinal direction of the housing 10.

[0171] The casing 53 is formed in a cylindrical shape extending along the longitudinal direction of the housing 10 and the support base 50, and has a distance measurement light source 51 attached to one side in the same direction, i.e., one end corresponding to the rear side of the housing 10, while a light projecting lens 52 is attached to the other end corresponding to the front side of the housing 10. The space between the distance measurement light source 51 and the light projecting lens 52 is sealed in a substantially airtight manner.

[0172] The distance measurement light source 51 emits distance measurement light toward the front side of the housing 10 in accordance with a control signal input from the control unit 101. Specifically, the distance measurement light source 51 can emit laser light in the visible light range as the distance measurement light. In particular, the distance measurement light source 51 according to this embodiment emits red laser light having a wavelength around 690 nm as the distance measurement light.

[0173] The distance measurement light source 51 is also fixed in a position such that the optical axis Ao of the red laser light emitted as distance measurement light is aligned along the longitudinal direction of the casing 53. Therefore, the optical axis Ao of the distance measurement light is aligned along the longitudinal direction of the housing 10 and the support base 50, passes through the center of the light projecting lens 52, and reaches the outside of the casing 53.

[0174] The light projecting lens 52 is located in the longitudinal direction of the support base 50 between the pair of light receiving elements 56L, 56R in the distance measurement light receiving unit 5B and the light receiving lens 57. The light projecting lens 52 is oriented so that the optical axis Ao of the distance measurement light passes through it.

[0175] The projection lens 52 may be, for example, a plano-convex lens, and may be fixed in a position with its spherical convex surface facing the outside of the casing 53. The projection lens 52 collects the distance measurement light emitted from the distance measurement light source 51 and emits it to the outside of the casing 53. The distance measurement light emitted to the outside of the casing 53 reaches between the guide plates 54L and 54R.

[0176] The guide plates 54L, 54R are configured as a pair of members aligned in the short-side direction of the support base 50, and each may be a plate-like body extending in the long-side direction of the support base 50. A space for emitting distance measurement light is defined between one guide plate 54L and the other guide plate 54R. The distance measurement light emitted to the outside of the casing 53 passes through the defined space and is output.

[0177] Therefore, the distance measurement light emitted from the distance measurement light source 51 passes through the space inside the casing 53, the center of the light projecting lens 52, and the space between the guide plates 54L and 54R, and is output to the outside of the distance measurement unit 5. The distance measurement light thus output is reflected by the bend mirror 59 and the dichroic mirror 35a in the downstream merging mechanism 35, and enters the laser light scanning unit 4.

[0178] The distance measurement light incident on the laser light scanning unit 4 is reflected in turn by the first mirror 41a of the first scanner 41 and the second mirror 42a of the second scanner 42, and exits the marker head 1 from the transparent window 19.

[0179] As described in the explanation of the laser light scanning unit 4, by adjusting the rotational attitude of the first mirror 41a of the first scanner 41, it is possible to scan the surface of the workpiece W with the distance measuring light in a first direction. At the same time, by operating the motor of the second scanner 42 to adjust the rotational attitude of the second mirror 42a, it is possible to scan the surface of the workpiece W with the distance measuring light in a second direction.

[0180] The scanned distance measurement light is reflected on the surface of the workpiece W. A portion of the reflected distance measurement light (hereinafter also referred to as "reflected light") enters the inside of the marker head 1 through the transmission window 19. The reflected light that entered the inside of the marker head 1 returns to the laser light guide unit 3 via the laser light scanning unit 4. Since the reflected light has the same wavelength as the distance measurement light, it is reflected by the dichroic mirror 35a of the downstream merging mechanism 35 in the laser light guide unit 3 and enters the distance measurement unit 5 via the bend mirror 59.

[0181] -Distance measurement light receiver 5B- The distance measurement light receiving unit 5B is provided inside the housing 10 and is configured to receive the distance measurement light (equivalent to the aforementioned "reflected light") emitted from the distance measurement light emitting unit 5A and reflected by the workpiece W.

[0182] Specifically, the distance measurement light receiving unit 5B has a pair of light receiving elements 56L, 56R and a light receiving lens 57. The pair of light receiving elements 56L, 56R are each arranged at the rear end of the support base 50, while the light receiving lens 57 is each arranged at the front end of the support base 50. Therefore, the pair of light receiving elements 56L, 56R and the light receiving lens 57 are arranged substantially along the longitudinal direction of the housing 10 and the support base 50.

[0183] The pair of light receiving elements 56L, 56R are arranged inside the housing 10 with their optical axes sandwiching the optical axis Ao of the distance measurement light at the distance measurement light emitting unit 5A. The pair of light receiving elements 56L, 56R each receive reflected light that has returned to the laser light scanning unit 4.

[0184] More specifically, the pair of light receiving elements 56L, 56R are aligned in a direction perpendicular to the optical axis Ao of the distance measurement light emitting unit 5A. In this embodiment, the alignment direction of the pair of light receiving elements 56L, 56R is the same as the short-side direction of the housing 10 and the support base 50, i.e., the left-right direction. In this direction, one light receiving element 56L is arranged to the left of the distance measurement light source 51, and the other light receiving element 56R is arranged to the right of the distance measurement light source 51.

[0185] The pair of light receiving elements 56L, 56R each have a light receiving surface oriented diagonally forward, detect the receiving position of the reflected light on each light receiving surface, and output a signal (detection signal) indicating the detection result. The detection signal output from each of the light receiving elements 56L, 56R is input to the marker controller 100 and then reaches the distance measurement unit 103.

[0186] Elements that can be used as each of the light receiving elements 56L and 56R include, for example, a CMOS image sensor made of a complementary MOS (CMOS), a CCD image sensor made of a charge-coupled device (CCD), a position sensitive detector (PSD), etc.

[0187] In this embodiment, each of the light receiving elements 56L and 56R is configured using a CMOS image sensor. In this case, each of the light receiving elements 56L and 56R can detect not only the light receiving position of the reflected light but also the distribution of the amount of received light (light receiving waveform). In other words, when each of the light receiving elements 56L and 56R is configured using a CMOS image sensor, pixels are arranged at least in the left-right direction on each light receiving surface. In this case, each of the light receiving elements 56L and 56R can read out a signal for each pixel, amplify it, and output it to the outside. The intensity of the signal at each pixel is determined based on the intensity of the reflected light at the spot when the reflected light forms a spot on the light receiving surface.

[0188] When the light receiving elements 56L, 56R are configured using elements capable of detecting the distribution of the amount of received light (light receiving waveform), such as a CMOS image sensor, the amount of received light at each of the light receiving elements 56L, 56R can be adjusted using the intensity of the distance measurement light, i.e., the intensity of the distance measurement light emitted from the distance measurement light emitting unit 5A (hereinafter also referred to as the "amount of projected light"), and the gain used when amplifying the signal for each pixel (hereinafter also referred to as the "light receiving gain"). In addition to the gain, the amount of received light can also be adjusted using the exposure time of each of the light receiving elements 56L, 56R.

[0189] The pair of light receiving elements 56L, 56R according to this embodiment can detect at least the peak position indicating the position at which reflected light is received and the amount of the reflected light received. For example, the height of the peak in the distribution of the amount of received reflected light can be used as an index indicating the amount of received light. Alternatively, the sum, average, or integral value of the distribution of the amount of received light may be used.

[0190] In this embodiment, the peak position of the distribution of the amount of received light is used as an index indicating the position at which reflected light is received. However, instead of this, the center of gravity of the distribution of the amount of received light may be used.

[0191] The light-receiving lens 57 is disposed inside the housing 10 so that the optical axes of the pair of light-receiving elements 56L, 56R pass through it. The light-receiving lens 57 is also provided midway along the optical path connecting the downstream-side merging mechanism 35 and the pair of light-receiving elements 56L, 56R, and can focus the reflected light that has passed through the downstream-side merging mechanism 35 onto the light-receiving surfaces of the pair of light-receiving elements 56L, 56R.

[0192] The light receiving lens 57 collects the reflected light returning to the laser light scanning unit 4, and forms a spot of the reflected light on the light receiving surface of each of the light receiving elements 56L, 56R. Each of the light receiving elements 56L, 56R outputs a signal indicating the peak position of the spot thus formed and the amount of received light to the distance measurement unit 103.

[0193] The laser processing device L can basically measure the distance to the surface of the workpiece W based on the light receiving position of the reflected light on the light receiving surface of each of the light receiving elements 56L, 56R (in this embodiment, the position of the peak of the spot). The so-called triangulation method is used as the distance measuring method.

[0194] -About distance measurement methods- Fig. 9 is a diagram illustrating the triangulation method. Although only the distance measurement unit 5 is shown in Fig. 9, the following description can also be applied to the case where distance measurement light is emitted via the laser light scanning unit 4 as described above.

[0195] 9, when distance measurement light is emitted from the distance measurement light source 51 in the distance measurement light emitting unit 5A, the distance measurement light is irradiated onto the surface of the workpiece W. When the distance measurement light is reflected by the workpiece W, the reflected light (particularly the diffuse reflected light) propagates approximately isotropically, assuming that the influence of specular reflection is removed.

[0196] The propagating reflected light includes a component that enters the light receiving element 56L via the light receiving lens 57, but the angle of incidence of the incident light on the light receiving element 56L increases or decreases depending on the distance between the marker head 1 and the workpiece W. When the angle of incidence on the light receiving element 56L increases or decreases, the light receiving position on the light receiving surface 56a is displaced.

[0197] In this way, the distance between the marker head 1 and the workpiece W and the light receiving position on the light receiving surface 56a are associated with a predetermined relationship. Therefore, by grasping this relationship in advance and storing it, for example, in the marker controller 100, it is possible to calculate the distance between the marker head 1 and the workpiece W from the light receiving position on the light receiving surface 56a. This calculation method is nothing other than a technique using the so-called triangulation method.

[0198] That is, the distance measurement unit 103 measures the distance from the laser processing device L to the surface of the workpiece W by a triangulation method based on the reception position of the distance measurement light in the distance measurement light receiving unit 5B.

[0199] Specifically, the condition setting storage unit 102 previously stores the relationship between the light receiving position on the light receiving surface 56a and the distance from the marker head 1 to the surface of the workpiece W. Meanwhile, the distance measurement unit 103 receives a signal indicating the light receiving position of the distance measuring light in the distance measuring light receiving unit 5B, more specifically, the peak position of the spot formed on the light receiving surface 56a by the reflected light.

[0200] The distance measurement unit 103 measures the distance to the surface of the workpiece W based on the signal thus input and the relationship stored in the condition setting storage unit 102. The measurement value thus obtained is input to, for example, the control unit 101 and used by the control unit 101 to control the Z scanner 33 and the like.

[0201] For example, the laser processing device L automatically or manually determines the areas (printing points) on the surface of the workpiece W that will be processed by the marker head 1. Next, prior to performing the printing process, the laser processing device L measures the distance to each printing point (more precisely, to distance measurement points set around the printing points) and determines the control parameters of the Z scanner 33 so that the focal position matches that distance. The laser processing device L operates the Z scanner 33 based on the control parameters thus determined, and then performs the printing process on the workpiece W using near-infrared laser light.

[0202] -About the machining reference surface- FIG. 10 is a diagram illustrating the machining reference plane Rb. As illustrated in FIGS. 3A, 3B, and 10, the distance measurement light for measuring the distance to each printing point and the near-infrared laser light irradiated onto each printing point both pass through the transmission window 19 and reach the workpiece W. Here, each printing point is provided within a machining area R1 set on the surface of the workpiece W. The setting of the machining area R1 is performed by the control unit 101. By setting the machining area R1, it is possible to specify the part of each workpiece W to be machined. However, when performing printing on multiple workpieces W, the location of the printing point and therefore the machining area R1 may differ for each workpiece W depending on the surface condition, such as unevenness.

[0203] Therefore, in order to precisely scan the distance measuring light and the near-infrared laser light, an index is required that is unrelated to the surface condition of the workpiece W. Therefore, the laser processing apparatus L according to this embodiment (particularly, the control unit 101 in the marker controller 100) is configured to scan the distance measuring light and the near-infrared laser light based on position information based on a processing reference plane Rb provided outside the housing 10, as exemplified in Fig. 10 .

[0204] This processing reference surface Rb is located on the opposite side of the transparent member 19b from the laser light scanning unit 4. Specifically, the processing reference surface Rb is provided below the transparent member 19b and is disposed at a position where the distance from the transparent member 19b is a predetermined value. As a result of this arrangement, the laser light scanning unit 4 faces the processing reference surface Rb through the transparent member 19b.

[0205] As will be described later, the transparent member 19b according to this embodiment is configured as a flat member. Specifically, the central axis perpendicular to the transparent member 19b also perpendicularly intersects the processing reference plane Rb. As a result of this configuration, the processing reference plane Rb according to this embodiment extends parallel to the transparent member 19b, as shown in FIG. 10.

[0206] The laser light irradiated into the processing region R1 is controlled based on position information based on the processing reference plane Rb, for example, the irradiation positions of the near-infrared laser light and the distance measurement light on the processing reference plane Rb. Specifically, the control unit 101 according to this embodiment performs two-dimensional scanning with the near-infrared laser light and the distance measurement light along a direction parallel to the processing reference plane Rb based on the position information based on the processing reference plane Rb. By using the processing reference plane Rb, for example, it is possible to easily form a common processing pattern on multiple workpieces W of different heights. This makes it possible to suppress variations in printing accuracy, printing quality, etc. between workpieces W.

[0207] As described above, the laser beam scanning unit 4 faces the processing reference surface Rb through the transparent member 19b. In this embodiment, not only the laser beam scanning unit 4 but also the wide-area camera 6 described above is configured to function through the transparent member 19b.

[0208] The configurations of the transmission window 19 and the wide-area camera 6 will be explained below in order.

[0209] (Transparent window 19) Fig. 11 is a bottom view illustrating the configuration of the transmission window 19 and the wide-area camera 6, Fig. 12 is a cross-sectional view illustrating the configuration of the transmission window 19 and the wide-area camera 6, and Fig. 13 is a longitudinal cross-sectional view illustrating the configuration of the transmission window 19 and the wide-area camera 6. The cross-section shown in Fig. 12 corresponds to the AA cross-section in Fig. 11. The longitudinal cross-section shown in Fig. 13 corresponds to the BB cross-section in Fig. 11.

[0210] As shown in Figures 11 to 13, the transparent window 19 is formed on the outer surface of the housing 10, and allows the near-infrared laser light scanned two-dimensionally by the laser light scanning unit 4 and the distance measurement light emitted from the distance measurement unit 5 to exit the housing 10.

[0211] Specifically, the transmission window 19 has a through-hole 19a provided on the outer surface of the housing 10 and a transparent member 19b attached to the through-hole 19a. Of these, the through-hole 19a is formed in a substantially circular shape and passes through the bottom plate 10a of the housing 10 in the vertical direction.

[0212] On the other hand, the transparent member 19b is fitted into the through-hole 19a and is configured to allow the near-infrared laser light and the distance measuring light emitted from the transmission window 19 to pass through.

[0213] Specifically, transparent member 19b is made of a substantially circular glass plate. When transparent member 19b is considered to be a perfect circle, its center is located directly below second mirror 42a, as shown in Figures 11 and 12. By fitting transparent member 19b into through-hole 19a, the space within housing 10 can be sealed airtight.

[0214] Furthermore, the transparent member 19b is a flat member in order to intentionally suppress the lens effect. Specifically, the radius of curvature of the transparent member 19b is set to be larger than that of a general fθ lens. By setting the radius of curvature to be larger, the transparent member 19b according to this embodiment can be regarded as a flat member that has no lens effect or a low lens effect (wherein the lens effect is substantially non-existent).

[0215] More specifically, the radius of curvature of transparent member 19b may be set within a range of 10,000 mm or more and 100,000 mm or less, and more preferably, the radius of curvature of transparent member 19b may be set within a range of 50,000 mm or more and 100,000 mm or less.

[0216] (Wide-area camera 6) The wide-area camera 6 as an imaging unit is configured to capture an image of the workpiece W through the transparent window 19 to generate a workpiece image Pw including at least a part of the processing area R1 (see also FIG. 18). In the example shown in FIG. 10, the entire area that can be scanned by the laser light scanning unit 4 is the processing area R1, but this is not limited to this example. A part of the scannable area may also be the processing area R1.

[0217] 10, the wide-area camera 6 is disposed within the housing 10 with its imaging optical axis Ac perpendicular to the processing reference plane Rb. Specifically, the wide-area camera 6 according to this embodiment has an imaging optical lens 61 and an imaging element 62 that forms an image using light captured by the optical lens 61, and is fixed with the optical lens 61 facing downward. The imaging optical axis Ac of the wide-area camera 6 extends linearly downward and is perpendicular to both the transparent member 19b and the processing reference plane Rb. Meanwhile, the optical axis Az of the near-infrared laser light emitted from the transmission window 19 (hereinafter also referred to as the "laser optical axis") extends downward from the second mirror 42a of the second scanner 42, as shown in FIG. 10. The imaging optical axis Ac is parallel to the laser optical axis Az, but the two optical axes are independent of each other.

[0218] In this way, the imaging optical axis Ac according to this embodiment is non-coaxial with the optical axis Az (hereinafter also referred to as the "laser optical axis") of the near-infrared laser light emitted from the transmission window 19. The light for generating the workpiece image is taken in by the optical lens 61 through an optical path independent of the near-infrared laser light. However, if the imaging optical axis Ac and the laser optical axis Az are separated too far from each other, a misalignment will occur between the imaging field of view Fv of the wide-area camera 6 and the area to be machined by the near-infrared laser light (machining area R1), which may reduce the usability of the laser processing apparatus L.

[0219] Therefore, the wide-area camera 6 according to this embodiment is laid out so that the imaging optical axis Ac is non-coaxial with the laser optical axis Az, but the imaging optical axis Ac and the laser optical axis Az are as close as possible to each other.

[0220] Specifically, the wide-area camera 6 is arranged closer to the second scanner 42 than the first scanner 41. By arranging the wide-area camera 6 and the second scanner 42 closer to each other, the imaging optical axis Ac and the laser optical axis Az can be arranged as close as possible to each other.

[0221] More specifically, in this embodiment, the wide-area camera 6 is arranged in the order of the first scanner 41, the second scanner 42, and the wide-area camera 6 along a direction perpendicular to the optical axis connecting the Z scanner 33 and the laser light scanning unit 4 (specifically, the optical axis extending along the downstream optical path Pd).

[0222] 7, the downstream optical path Pd extends rearward along the front-rear direction. Therefore, in the laser processing apparatus L according to this embodiment, the first scanner 41, the second scanner 42, and the wide-area camera 6 are arranged in this order from the right side of the drawing along the left-right direction, as shown in FIG. 12 (see also FIGS. 6 and 7).

[0223] 6 and 7, the wide area camera 6 according to this embodiment is located behind the downstream merging mechanism 35 and the bend mirror 59 and at the same position as the first scanner 41 and the second scanner 42 in the front-to-rear direction. By arranging it in this manner, it is possible to prevent the distance measurement light propagating between the downstream merging mechanism 35 and the bend mirror 59 from being included in the imaging field of view Fv of the wide area camera 6. In addition, in the height direction, the wide area camera 6 is located at approximately the same height as the second mirror 42a.

[0224] Furthermore, the imaging field of view Fv of the wide area camera 6 tapers from the optical lens 61 with the imaging optical axis Ac as the central axis. As can be seen from FIG. 10, the wide area camera 6 according to this embodiment is provided in a position where the imaging field of view Fv does not include the laser light scanning unit 4. Furthermore, as can be seen from the same figure, the wide area camera 6 according to this embodiment is provided in a position where the imaging field of view Fv includes part of the edge of the transparent window 19, in particular part of the peripheral portion of the through-hole 19a (the left end of the transparent window 19 on the page in FIG. 10). Therefore, the workpiece image Pw generated by the wide area camera 6 does not include the laser light scanning unit 4, but does include part of the edge of the transparent window 19.

[0225] Hereinafter, a portion of the edge of the transparent window 19 that will be reflected in the workpiece image Pw will be simply referred to as "a portion of the edge of the transparent window 19" or "a portion of the edge," and will be denoted by the reference numeral "19c." For the portion of the edge 19c, please also refer to the bottom view of FIG. 11.

[0226] Furthermore, the imaging element 62 constituting the wide-area camera 6 is formed in a rectangular shape extending in a predetermined direction. Therefore, the imaging field of view Fv of the wide-area camera 6, and therefore the imaging region R2 that crosses the imaging field of view Fv in a direction perpendicular to the imaging optical axis Ac, also has a long dimension in the predetermined direction. This imaging region R2 is configured to include at least a portion of the processing region R1. For example, the imaging region R2 illustrated in FIG. 10 includes the entire processing region R1.

[0227] The imaging element 62 according to this embodiment is disposed so that its longitudinal direction is parallel to the arrangement direction of the wide area camera 6 and the second scanner 42. By disposing them in this manner, the wide area camera 6 and the second scanner 42 are aligned along the longitudinal direction of the imaging field of view Fv and the imaging region R2. As a result, as shown in the lower diagram of Fig. 10, the center Oz of the region that can be scanned by the laser light scanning unit 4 (the processing region R1 in this example) is offset in the longitudinal direction of the imaging region R2 with respect to the center Oc of the imaging region R2.

[0228] Here, the "center Oz of the scannable area" refers to the intersection of the laser optical axis Az and the processing area R1 when the near-infrared laser light is emitted in a direction where the laser optical axis Az and the processing reference plane Rb are perpendicular to each other, as shown in Fig. 10. Also, the "center Oc of the imaging area R2" refers to the intersection of the imaging optical axis Ac and the imaging area R2 when the imaging area R2 is set so as to be flush with the processing area R1.

[0229] Thus, in this embodiment, when near-infrared laser light is emitted perpendicular to the processing reference surface Rb, the position where the laser optical axis Az intersects with the processing reference surface Rb is offset from the position where the imaging optical axis Ac intersects with the processing reference surface Rb.

[0230] The wide-area camera 6 then generates an image corresponding to the imaging area R2 as a workpiece image Pw that includes at least a portion of the machining area R1. As described above, this workpiece image Pw reflects not only the machining area R1 but also a portion 19c of the edge of the transparent window 19 (see also FIG. 18(a)). The workpiece image Pw generated by the wide-area camera 6 is output to the control unit 101.

[0231] The laser processing device L can also generate the workpiece image Pw by operating the narrow area camera 37 instead of the wide area camera 6. The area that can be imaged by the narrow area camera 37 is narrower than the imaging area R2 of the wide area camera 6. In other words, the wide area camera 6 can image the surface of the workpiece W over a wider range than the narrow area camera 37.

[0232] Next, a specific method of using the laser processing system S will be explained.

[0233] <How to use the laser processing system S> Fig. 14 is a flowchart showing a method of using the laser processing system S. Fig. 15 is a flowchart showing an example of a procedure for creating print settings, and Fig. 16 is a flowchart showing an example of an operation procedure for the laser processing device L.

[0234] 17 is a diagram illustrating an example of the relationship between the machining area R1 of the workpiece W and the setting plane R4 on the display unit 801. FIG. 18 is a diagram illustrating the generation of a partial image Pp from the workpiece image Pw.

[0235] A laser processing system S equipped with a laser processing device L configured as a laser marker can be installed and operated, for example, on a production line in a factory. In operation, first, prior to starting the production line, condition settings (printing settings) are created, such as the installation position of a work W that will be transported along the line, and the output of the laser light and distance measurement light to be irradiated onto the work W (step S1).

[0236] The print settings created in step S1 are transferred to and stored in the marker controller 100 and / or the operation terminal 800, or are read by the marker controller 100 immediately after creation (step S2).

[0237] When the production line is in operation, the marker controller 100 refers to the print settings that have been stored in advance or that have been read immediately after creation. The laser processing device L is operated based on the referenced print settings and performs print processing on each workpiece W that is transported on the line (step S3).

[0238] (Creating print settings) FIG. 15 illustrates a specific example of the process in step S1 of FIG.

[0239] First, in step S11a of step S11, the wide-area camera 6 built into the laser processing device L generates a workpiece image Pw corresponding to the entire imaging area R2 (see (a) of FIG. 18). A part of the edge 19c of the transparent window 19 is reflected in this workpiece image Pw.

[0240] Then, in step S11b of step S11, the control unit 101 generates a partial image Pp by excluding a portion of the edge 19c from the workpiece image Pw (see (b) of FIG. 18). This partial image Pp is generated as an image capturing at least a portion of the processing area R1. The partial image Pp generated by the control unit 101 is output to the operation terminal 800.

[0241] Then, the display unit 801 of the operation terminal 800 displays a setting plane R4 corresponding to the machining area R1, and also displays a partial image Pp on the setting plane R4 (see (c) of FIG. 18). This allows the coordinates on the machining area R1, i.e., the coordinates on the surface of the workpiece W, to be associated with the coordinates on the setting plane R4 on the display unit 801.

[0242] In the following step S12, the installation position of the workpiece W is corrected based on the partial image Pp captured in step S11. Although details are omitted, this step corrects the inclination of the surface of the workpiece W with respect to the XY plane (the plane formed by the X and Y directions described above) and manually / automatically corrects the rotation (θ rotation) of this surface around the Z axis (the axis extending along the Z direction described above).

[0243] In the following step S13, the setting unit 107 sets processing conditions. The setting unit 107 sets the processing conditions by reading out the contents stored in the condition setting storage unit 102 or the like, or by reading operation inputs via the operation terminal 800.

[0244] The processing conditions include a printing pattern (marking pattern) that indicates the printing content, etc., and a printing block that includes this printing pattern. The printing block can be used to adjust the layout, size, rotational posture, etc. of the printing pattern.

[0245] In the example shown in FIG. 18(c), a print pattern P consisting of the letter "A" and a rectangular print block B containing this are laid out on the surface of the workpiece W and are displayed via a setting surface R4. This print block B is set on the setting surface R4 so as to be superimposed on the partial image Pp. The setting of the print block B is performed by the setting unit 107.

[0246] Note that the printing pattern is an example of a "processing pattern," and the printing block is an example of a "processing block." When applying to laser processing other than printing processing, the name should be appropriate for the application.

[0247] Instead of the example shown in FIG. 18(c), multiple workpieces W may be displayed on the setting surface R4. Also, multiple print blocks may be provided for each workpiece W. As for the print pattern, for example, a character string such as "ABC" may be used, or a pattern other than a character string, such as a QR code (registered trademark), may be used.

[0248] In this way, the setting unit 107 according to this embodiment exemplifies a "processing block setting unit" in that it can set a print block as a processing block on the setting surface R4.

[0249] The processing conditions also include laser conditions, which include at least one of the target output (laser power) of the near-infrared laser beam, the repetition frequency of the near-infrared laser beam, and the scanning speed (scanning speed) of the near-infrared laser beam by the laser beam scanning unit 4. When laser oscillation is performed using a Q switch, as in the laser processing apparatus L according to this embodiment, the repetition frequency substantially matches the Q switch frequency.

[0250] In the following step S14, the print blocks are laid out, and the coordinates (local coordinates) of the print blocks on the setting surface R4 are stored in the condition setting storage unit 102 or the like.

[0251] Generally, when a production line is operated, each workpiece W that is processed sequentially will have a positional deviation in the X and Y directions (XY directions). The laser processing apparatus L according to this embodiment can correct such positional deviation by using various methods. To this end, in step S15, conditions are set for correcting the positional deviation in the X and Y directions.

[0252] As a method for correcting the positional deviation in the X and Y directions, for example, a pattern search can be used. In this case, in this step S15, a model image for the pattern search is determined as a condition related to the pattern search (search condition).

[0253] Generally, when a production line is operated, each workpiece W that is processed sequentially will have a positional deviation in the Z direction. Such a positional deviation is undesirable because it leads to a deviation in the focal position of the near-infrared laser light. The laser processing apparatus L according to this embodiment is equipped with a distance measuring unit 5, and therefore can detect a positional deviation in the Z direction based on the distance to the surface of the workpiece W. This makes it possible to correct the positional deviation in the Z direction, and ultimately the deviation in the focal position. To this end, in step S16, conditions are set to correct the positional deviation in the Z direction.

[0254] Specifically, in step S16, conditions (distance measurement conditions) related to the distance measurement unit 5 are determined. The setting unit 107 according to this embodiment determines, as the distance measurement conditions, distance measurement points to be set within at least the partial area (partial area corresponding to the print block including the print pattern) in the processing area R1 where the print pattern is to be formed. These distance measurement points indicate the coordinates at which the distance from the laser processing device L is measured.

[0255] The partial area referred to here may be the entire surface of the workpiece W, a part of the surface of the workpiece W, or an area shifted from the surface of the workpiece W. The partial area may be at least an area associated with the print pattern to be formed.

[0256] In the following step S17, the marker controller 100 completes the creation of the print settings.

[0257] (Printing processing) Fig. 16 illustrates a specific example of the process in step S3 of Fig. 14. That is, the process shown in Fig. 16 is executed in order for each workpiece W that flows through the production line when the production line is put into operation.

[0258] First, in step S31, the marker controller 100 reads the print settings indicating details of the print block, etc. Then, in step S32a of step S32, the wide-area camera 6 built into the laser processing device L captures an image of an imaging area R2 indicating at least a part of the processing area R1, thereby generating a workpiece image Pw corresponding to the imaging area R2 (see (a) of FIG. 18). A part of the edge 19c of the transparent window 19 is reflected in this workpiece image Pw.

[0259] Then, in step S32b of step S32, the control unit 101 generates a partial image Pp by excluding a portion of the edge 19c from the workpiece image Pw (see (b) of FIG. 18). This partial image Pp is generated as an image capturing at least a portion of the processing area R1. The partial image Pp generated by the control unit 101 is output to the operation terminal 800.

[0260] Then, the display unit 801 of the operation terminal 800 displays a setting plane R4 corresponding to the processing region R1, and also displays a partial image Pp on the setting plane R4 (see FIG. 18(c)).

[0261] In the following step S33, the marker controller 100 reads the search conditions set in step S15 of Fig. 11. Subsequently, in step S34, the marker controller 100 performs a pattern search based on the search conditions read in step S33, and detects positional deviation of the workpiece W in the X and Y directions.

[0262] In the following step S35, the marker controller 100 reads the distance measurement conditions set in step S16 of Fig. 11. Subsequently, in step S36, the distance measurement unit 103 in the marker controller 100 measures the distance to the distance measurement point set as the distance measurement condition, and detects the positional deviation of the workpiece W in the Z direction based on the measurement result.

[0263] In the following step S37, the marker controller 100 corrects the positional deviation of the workpiece W in the X and Y directions. Specifically, the setting unit 107 in the marker controller 100 corrects the position of the print block on the setting surface R4, more specifically, the coordinates (local coordinates) of the print block on the setting surface R4, based on the partial image Pp displayed on the setting surface R4.

[0264] In the following step S38, the marker controller 100 corrects the positional deviation of the workpiece W in the Z direction. Specifically, the Z scanner 33 in the marker controller 100 adjusts the focal position for each print block based on the measurement result in step S36.

[0265] In the following step S39, the marker controller 100 outputs an excitation laser beam to the marker head 1, and executes the printing process using a near-infrared laser beam generated based on the excitation laser beam.

[0266] (Layout of wide-area camera 6) As shown in FIG. 10, the wide-area camera 6 serving as an imaging unit is disposed within the housing 10 in an orientation in which its imaging optical axis Ac is perpendicular to the machining reference plane Rb. By disposing the camera in this manner, the workpiece W can be imaged from directly above, rather than from diagonally above. This eliminates distortion of the workpiece image Pw as the captured image. Furthermore, since it is no longer necessary to make the imaging optical axis Ac and the near-infrared laser light used for machining coaxially, it is possible to widen the imaging field of view Fv.

[0267] However, when positioned in this manner, the wide-area camera 6 will capture an image of the workpiece W through the transparent member 19b. This raises concerns about distortion of the workpiece image Pw due to the transparent member 19b. However, after extensive research, the inventors of the present application came up with the idea of ​​intentionally using a flat member that has no lens effect (i.e., no lens effect occurs) or a low lens effect as the transparent member 19b.

[0268] That is, by using the transparent member 19b with no or low lens effect, distortion of the workpiece image Pw caused by the member 19b is suppressed, thereby reducing the load on the control system including the control unit 101.

[0269] In this way, the imaging field of view Fv of the wide area camera 6 can be widened while suppressing the load on the control system.

[0270] Furthermore, by making the imaging optical axis Ac and the laser optical axis Az non-coaxial, the size of the imaging field of view Fv becomes independent of the configuration of the laser light scanning unit 4. This is advantageous in widening the imaging field of view Fv.

[0271] Furthermore, as illustrated in Figure 10, by configuring the imaging field of view Fv so that the laser light scanning unit 4 is not included, it is possible to prevent the laser light scanning unit 4 from getting in the way when generating the workpiece image Pw.

[0272] Furthermore, as shown in FIG. 18, by displaying a partial image Pp obtained by excluding a portion 19c of the edge from the workpiece image Pw on the setting plane R4, the usability of the laser processing device L can be improved.

[0273] Furthermore, as illustrated in step S37 of Fig. 16, the position of the print block can be adjusted based on the partial image Pp, thereby enabling more precise laser processing to be achieved.

[0274] 12, by placing the wide-area camera 6 closer to the second scanner 42 than to the first scanner 41, it is possible to reduce the deviation between the imaging field Fv of the wide-area camera 6 and the area actually irradiated with the near-infrared laser light. This is effective in more appropriately setting the processing area R1, etc.

[0275] 7 and other examples, by arranging the first scanner 41, the second scanner 42, and the wide area camera 6 in this order along a direction perpendicular to the downstream optical path Pd, it is possible to place the wide area camera 6 close to the second scanner 42 while keeping the near-infrared laser light propagating from the Z scanner 33 to the laser light scanning unit 4 as far away as possible from the wide area camera 6. This makes it possible to suppress the deviation between the imaging field of view Fv of the wide area camera 6 and the area actually irradiated with the near-infrared laser light, and to more appropriately set the processing area R1, etc.

[0276] Furthermore, as a result of extensive research conducted by the inventors of the present application, it has been discovered that by setting the radius of curvature of the transparent member 19b to 10,000 mm or more, the distortion of the workpiece image Pw caused by the transparent member 19b can be kept within an acceptable range.

[0277] <<Modification of Marker Head 1>> In the above embodiment, the wide-area camera 6 as the imaging unit was configured so that the imaging field of view Fv did not include the laser light scanning unit 4 and the imaging field of view Fv did not include part of the edge 19c, but this configuration is not limited to this.

[0278] Fig. 19 is a diagram corresponding to Fig. 10, showing a modified example of the marker head 1. Hereinafter, the modified example of the marker head 1 will be given the symbol "1'" and will be simply referred to as "marker head 1'".

[0279] As shown in FIG. 19, the transparent member 19b in the marker head 1' is made of a flat member that does not produce a lens effect (a flat member that has no lens effect or a low lens effect), similar to the above embodiment.

[0280] Furthermore, the marker head 1' has the same functions as those of the above embodiment, but is equipped with a wide-area camera 6 and a second scanner 42 that have a different layout from those of the above embodiment. Specifically, the wide-area camera 6 shown in Fig. 19 is disposed within the housing 10 in an orientation in which its imaging optical axis Ac is perpendicular to the machining reference surface Rb, and is provided at a position where the laser light scanning unit 4 (particularly the second scanner 42) is included in its imaging field of view Fv. Therefore, the laser light scanning unit 4 (particularly the second scanner 42) is reflected in the workpiece image Pw generated by the wide-area camera 6.

[0281] The marker head 1' can execute processing suited to such a layout. Specifically, the display unit 801 according to the modified example generates a partial image Pp by excluding the laser light scanning unit 4 from the workpiece image Pw, and displays this on the setting surface R4. Then, the setting unit 107 according to the modified example can correct the position of the print block on the setting surface R4 based on the partial image Pp thus displayed, as in the above embodiment.

[0282] In this way, by generating the partial image Pp excluding the laser light scanning unit 4, it is possible to improve the usability of the laser processing device L. Furthermore, by adjusting the position of the print block based on the partial image Pp, it is possible to achieve more precise laser processing.

[0283] Other Embodiments In the above embodiment, an example has been described in which one workpiece W is imaged, but the present invention is not limited to this example. For example, multiple workpieces W can be imaged simultaneously to generate workpiece images Pw and partial images Pp in which each workpiece W is captured. [Explanation of symbols]

[0284] 1 marker head 10. Cabinet 19 Transmission window (exit window) 19b Transparent material 19c Part of the edge 2 Laser light output section 3 Laser beam guide 33 Z scanner (focus adjustment unit) 4 Laser beam scanning unit 41 First Scanner 42 Second scanner 6 Wide-area camera (imaging unit) 100 Marker Controller 101 control unit (scanning control unit) 107 Setting section (processing block setting section) 110 Excitation light generation unit 800 Operation terminal 801 Display section Ac Imaging optical axis Az Laser optical axis (optical axis of laser light) Fv imaging field Pp Partial image Pw work image R1 machining area R4 setting screen Rb machining reference surface S Laser Processing System W Work (workpiece)

Claims

1. an excitation light generating unit that generates excitation light; a laser light output unit that generates a laser light based on the excitation light generated by the excitation light generating unit and emits the laser light; a laser beam scanning unit that irradiates the laser beam emitted from the laser beam output unit onto a workpiece and performs two-dimensional scanning within a processing region set on the surface of the workpiece; a housing in which at least the laser light output unit and the laser light scanning unit are provided; an exit window formed in the housing, through which the laser light scanned by the laser light scanning unit is emitted to the outside of the housing; a transparent member provided in the exit window portion and transmitting the laser light emitted from the exit window portion; an imaging unit that captures an image of the workpiece through the exit window to generate a workpiece image including at least a portion of the processing area; a laser processing device that scans laser light along a plane parallel to a processing reference plane based on position information based on the processing reference plane, the processing reference plane being located on the opposite side of the laser light scanning unit across the transparent member and extending parallel to the transparent member, the transparent member is a flat member that does not substantially produce a lens effect, The imaging unit is disposed in the housing with its imaging optical axis perpendicular to the processing reference surface. A laser processing device characterized by:

2. 2. The laser processing apparatus according to claim 1, The imaging optical axis is configured to be non-coaxial with the optical axis of the laser light emitted from the exit window portion. A laser processing device characterized by:

3. 3. The laser processing apparatus according to claim 1, The imaging unit is provided at a position where the imaging field of view does not include the laser beam scanning unit. A laser processing device characterized by:

4. 4. The laser processing apparatus according to claim 1, The imaging unit is provided at a position where a part of the edge of the exit window is included in its imaging field of view. A laser processing device characterized by:

5. 5. The laser processing apparatus according to claim 4, a display unit that displays a setting surface corresponding to the processing area; The display unit displays a partial image of the workpiece image excluding a part of the edge on the setting surface. A laser processing device characterized by:

6. 6. The laser processing apparatus according to claim 5, a scanning control unit that controls the laser beam scanning unit to form a predetermined processing pattern within the processing area; a processing block setting unit that sets a processing block including the processing pattern on the setting surface, The processing block setting unit corrects the position of the processing block on the setting surface based on the partial image. A laser processing device characterized by:

7. 3. The laser processing apparatus according to claim 1, The imaging unit is provided at a position where the imaging field of view includes the laser beam scanning unit. A laser processing device characterized by:

8. 8. The laser processing apparatus according to claim 7, a display unit that displays a setting surface corresponding to the processing area; The display unit displays a partial image of the workpiece image excluding the laser beam scanning unit on the setting surface. A laser processing device characterized by:

9. 9. The laser processing apparatus according to claim 8, a scanning control unit that controls the laser beam scanning unit to form a predetermined processing pattern within the processing area; a processing block setting unit that sets a processing block including the processing pattern on the setting surface, The processing block setting unit corrects the position of the processing block on the setting surface based on the partial image. A laser processing device characterized by:

10. 10. The laser processing apparatus according to claim 1, The laser light scanning unit a first scanner that scans the laser light emitted from the laser light output unit in a first direction; a second scanner that scans the laser light scanned by the first scanner in a second direction substantially perpendicular to the first direction, The imaging unit is disposed closer to the second scanner than to the first scanner. A laser processing device characterized by:

11. 11. The laser processing apparatus according to claim 10, a focus adjustment unit that is provided in the middle of an optical path from the laser light output unit to the laser light scanning unit and that adjusts a focus position of the laser light emitted from the laser light output unit; The first scanner, the second scanner, and the imaging unit are arranged in this order along a direction perpendicular to an optical axis connecting the focus adjustment unit and the laser light scanning unit. A laser processing device characterized by:

12. The laser processing apparatus according to any one of claims 1 to 11, The radius of curvature of the transparent member is set within a range of 10,000 mm or more and 100,000 mm or less. A laser processing device characterized by:

Images