Laser processing apparatus

Abstract

A laser processing apparatus that can maintain high processing precision of a workpiece even if the workpiece is misaligned, includes a setting section that sets a pattern region and a ranging position on a captured image, a condition setting storage section that stores image information in the pattern region, a position correction section that detects misalignment of a new workpiece different from the workpiece for which the pattern region is set, and corrects the ranging position on the new workpiece, a ranging section that measures a distance based on a light receiving position of ranging light in a ranging light receiving section, and a Z scanner that adjusts a focal position based on a measurement result of the ranging section before the workpiece is irradiated with laser light.

Description

TECHNICAL FIELD

[0001] The technology disclosed herein relates to a laser processing apparatus that performs processing by irradiating a workpiece with a laser, such as a laser marking apparatus. BACKGROUND

[0002] Conventionally, a laser processing apparatus capable of correcting a processing position by a laser is known.

[0003] For example, Japanese Patent Application Publication No. 2015-006674 discloses a laser processing apparatus configured to form a hole in a workpiece, in which an amount of deviation of a center position of the hole is calculated and an angle of a galvano mirror is corrected based on the amount of deviation thus calculated.

[0004] In addition, a laser processing apparatus disclosed in Japanese Patent Application Publication No. 2008-227377 is capable of adjusting a focal point position of a laser along a Z-axis direction so as to perform laser processing on a workpiece having a predetermined height.

[0005] However, such a correction method in Japanese Patent Application Publication No. 2015-006674 corrects only a position on a two-dimensional plane.

[0006] In this correction method, when a workpiece having a height is set as an object to be processed as disclosed in Japanese Patent Application Publication No. 2008-227377, processing accuracy can be reduced.

[0007] For example, in a case where a galvano mirror is used for two-dimensional scanning, a focal point position of a laser differs between a vicinity of a center of a processing region set on a workpiece and a vicinity of an edge of the processing region. Specifically, the focal point position becomes farther and farther away from the processing region as it advances from a central portion of the processing region toward the edge. Therefore, in position correction on a two-dimensional plane, the focal point position is likely to deviate after correction. This is problematic in terms of maintaining high processing accuracy. SUMMARY

[0008] The technology disclosed herein is made in view of this and aims to maintain high processing accuracy of a workpiece even if the workpiece is misaligned.

[0009] Specifically, according to one embodiment of the present disclosure, a laser processing apparatus includes an excitation light generation section that generates excitation light, a laser output section that generates a laser based on the excitation light generated by the excitation light generation section and emits the laser, a focal point adjustment section that adjusts a focal point position of the laser emitted from the laser output section, and a laser scanning section that irradiates a workpiece with the laser whose focal point position is adjusted by the focal point adjustment section and performs two-dimensional scanning within a processing region set on a surface of the workpiece.

[0010] According to an embodiment of the present disclosure, the laser processing apparatus includes: an imaging section that images the workpiece to generate an imaging image including at least a part of the processing region; a setting section that sets, on the imaging image, a correction region for identifying a position of the workpiece and a ranging position for measuring a distance to a surface of the workpiece; a storage section that stores image information in the correction region set by the setting section; and a position correction section that detects misalignment of a new workpiece from the image information stored in the storage section on an imaging image newly generated by the imaging section for a new workpiece different from the workpiece for which the correction region is set, and corrects a ranging position on the new workpiece corresponding to the ranging position set by the setting section.

[0011] The laser processing apparatus further includes: a ranging light emitting section that emits ranging light for measuring a distance from the laser processing apparatus to a surface of the new workpiece; a scanning control section that controls the laser scanning section to irradiate the ranging position corrected by the position correction section with the ranging light emitted by the ranging light emitting section; a ranging light receiving section that receives the ranging light returned via the laser scanning section after being reflected on the surface of the new workpiece; and a ranging section that measures a distance from the laser processing apparatus to the ranging position corrected by the position correction section based on a light-receiving position of the ranging light in the ranging light receiving section, and the focal point adjustment section adjusts the focal point position based on a measurement result of the ranging section before the new workpiece is irradiated with laser light.

[0012] Here, the "image information" can be the imaging image itself or edge information extracted from the imaging image.

[0013] According to the above configuration, the laser processing apparatus can detect misalignment of the workpiece from the position correction section, and correct the ranging position based on the detection result. Before the workpiece is irradiated with laser light, in a state where the ranging position has been corrected by the position correction section, the laser processing apparatus corrects the focal point position based on a measurement result of the ranging section.

[0014] In this way, even in a state where misalignment of the workpiece has been corrected, the workpiece can be maintained in alignment with the configuration for adjusting the focal point position, and high processing accuracy can be maintained.

[0015] In addition, according to another embodiment of the present disclosure, the scanning control section can control the laser scanning section to perform two-dimensional scanning taking into account the misalignment detected by the position correction section.

[0016] According to this configuration, the scanning control section performs two-dimensional scanning taking into account the misalignment. This is advantageous in terms of maintaining high processing accuracy of the workpiece.

[0017] According to still another embodiment of the present disclosure, the laser processing apparatus can further include a processing block setting section that sets a processing block that indicates a position of a processing pattern formed in a processing region and is associated with the ranging position to overlap with the captured image, and the position correction section can correct the position of the processing block based on the detection result of the misalignment.

[0018] According to this configuration, the ranging position associated with the processing block can be corrected by correcting the position of the processing block. This is advantageous in terms of maintaining high processing accuracy of the workpiece.

[0019] In addition, according to still another embodiment of the present disclosure, the setting section can set the ranging position within the processing block.

[0020] According to this configuration, it is advantageous in terms of more appropriately setting the ranging position and further maintaining high processing accuracy of the workpiece.

[0021] Further, according to still another embodiment of the present disclosure, the imaging section can include at least one of a first imaging section having an imaging optical axis that branches from a laser path from the laser output section to the laser scanning section and generates a captured image with the laser scanning section, and a second imaging section having an imaging optical axis independent of the laser path and generates a captured image without the laser scanning section, and the position correction section can correct the ranging position based on a newly generated captured image by at least one of the first imaging section and the second imaging section.

[0022] According to this configuration, it is advantageous in terms of more accurately correcting the ranging position and further maintaining high processing accuracy of the workpiece.

[0023] As described above, according to the laser processing apparatus, high processing accuracy can be maintained even when the workpiece is misaligned. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a diagram showing the overall configuration of a laser processing system;

[0025] Figure 2 is a block diagram showing the schematic configuration of a laser processing apparatus;

[0026] Figure 3A is a block diagram showing the schematic configuration of a marking head;

[0027] Figure 3B is a block diagram showing the schematic configuration of a marking head;

[0028] Figure 4 is a perspective view showing the appearance of a marking head;

[0029] Figure 5 is a diagram showing the configuration of a laser scanning section;

[0030] Figure 6 is a diagram showing the configuration of a laser guide section, a laser scanning section, and a distance measuring unit;

[0031] Figure 7 is a cross-sectional view showing the optical path connecting the laser guide section, the laser scanning section, and the distance measuring unit;

[0032] Figure 8 is a perspective view showing the optical path connecting the laser guide section, the laser scanning section, and the distance measuring unit;

[0033] Figure 9 is a diagram showing the triangulation method;

[0034] Figure 10 is a flowchart showing the method of using the laser processing system;

[0035] Figure 11 is a flowchart showing the process for creating a printing setting, a search setting, and a distance measuring setting;

[0036] Figure 12 is a diagram showing the relationship between a processing area and a setting surface;

[0037] Figure 13 is a diagram showing the display content of a display section;

[0038] Figure 14A is a diagram showing the specific process for setting a search condition;

[0039] Figure 14B is a diagram showing the specific process for setting a search condition;

[0040] Figure 14C is a diagram showing the specific process for setting a search condition;

[0041] Figure 14D is a diagram showing the specific process for setting a search condition;

[0042] Figure 15A is a diagram showing the specific process for setting a distance measuring condition;

[0043] Figure 15B is a diagram showing the specific process for setting a distance measuring condition;

[0044] Figure 15C is a diagram showing the specific process for setting a distance measuring condition;

[0045] Figure 15D is a diagram showing the specific process for setting a distance measuring condition;

[0046] Figure 16is a flow chart showing the operation process of the laser processing equipment;

[0047] Figure 17A is a diagram showing a specific process of pattern search;

[0048] Figure 17B is a diagram showing a specific process of pattern search;

[0049] Figure 17C is a diagram showing a specific process of pattern search;

[0050] Figure 17D is a diagram showing a specific process of pattern search;

[0051] Figure 18 is a diagram illustrating keystone correction; and

[0052] Figure 19 is a diagram showing the relationship between misalignment of a workpiece and a focus position. DETAILED DESCRIPTION

[0053] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. Note that the following description is given as an example.

[0054] That is, in this specification, a laser marker is described as an example of a laser processing device, but the technology disclosed herein can be applied to general laser application devices regardless of the names of the laser processing device and the laser marker.

[0055] Although printing is described as a typical example of processing in this specification, the technology can be used in various types of processing using laser light such as image marking, without being limited to printing.

[0056] <Overall Structure>

[0057] Figure 1 1 is a diagram showing the overall structure of a laser processing system S. Figure 2 2 is a diagram showing a schematic configuration of a laser processing apparatus L in a laser processing system S. FIG. Figure 1 The laser processing system S shown in FIG. 1 includes a laser processing apparatus L, an operation terminal 800 connected to the laser processing apparatus L, and an external device 900 .

[0058] Figure 1 and Figure 2 The laser processing apparatus L shown here irradiates a workpiece W, serving as a workpiece, with laser light emitted from a marking head 1, and performs three-dimensional scanning of the surface of the workpiece W to perform processing. The concept of "three-dimensional scanning" here is a general term for a combination of a two-dimensional operation of scanning the laser irradiation position on the surface of the workpiece W (so-called "two-dimensional scanning") and a one-dimensional operation of adjusting the laser focal position.

[0059] In particular, the laser processing apparatus L according to the present embodiment can emit laser light of a wavelength in the vicinity of 1064 nm as laser light for processing the workpiece W. This wavelength corresponds to a near-infrared (NIR) wavelength range. Therefore, in the following description, the laser light for processing the workpiece W is sometimes referred to as "near-infrared laser light" to distinguish it from other laser light. Of course, laser light having other wavelengths can be used for processing the workpiece W.

[0060] The laser processing apparatus L according to the present embodiment is capable of measuring the distance to the workpiece W (the height of the workpiece W) using the distance measuring unit 5 built into the marking head 1, and also uses this measurement result to adjust the focal position of this near-infrared laser light.

[0061] As shown in FIG. 1, the laser processing apparatus L includes the marking head 1 configured to emit laser light and the marking controller 100 configured to control the marking head 1. Figure 1 Figure 2 As shown in FIG. 1, the laser processing apparatus L includes the marking head 1 configured to emit laser light and the marking controller 100 configured to control the marking head 1.

[0062] In the present embodiment, the marking head 1 and the marking controller 100 are separate members, and are electrically connected via an electric wiring and optically coupled via an optical fiber cable.

[0063] More generally, one of the marking head 1 and the marking controller 100 can be incorporated into the other so as to be integrated. In this case, the optical fiber cable or the like can be omitted as appropriate.

[0064] The operation terminal 800 has, for example, a central processing unit (CPU) and a memory, and is connected to the marking controller 100. The operation terminal 800 functions as a terminal configured to set various processing conditions (also referred to as printing conditions) such as print settings and the like, and to display information related to laser processing to a user. The operation terminal 800 includes a display section 801 configured to display information to a user, an operation section 802 that receives operation input from a user, and a storage device 803 configured to store various types of information.

[0065] Specifically, the display section 801 is configured using, for example, a liquid crystal display or an organic EL panel. The display section 801 displays the operation state and the processing conditions of the laser processing apparatus L as information related to laser processing. On the other hand, the operation section 802 is configured using, for example, a keyboard and / or a pointing device. Here, the pointing device includes a mouse and / or a joystick. The operation section 802 is configured to receive operation input from a user, and is used to operate the marking head 1 via the marking controller 100.

[0066] ​The operation terminal 800 configured as described above can set the processing conditions in laser processing based on an input operation from the user. Examples of the processing conditions include at least one or more of a character string to be printed on the workpiece W, graphic content (mark pattern) such as a bar code and a QR code (registered trademark), output required for the laser (target output), and a scanning speed of the laser on the workpiece W.

[0067] The processing conditions according to the present embodiment also include conditions and parameters related to the distance measuring unit 5 (hereinafter, also referred to as "distance measuring conditions"). Examples of the distance measuring conditions include data associating a signal indicating a detection result of the distance measuring unit 5 with a distance to the surface of the workpiece W.

[0068] The processing conditions set by the operation terminal 800 are output to the marking controller 100 and stored in the condition setting storage section 102. The storage device 803 in the operation terminal 800 can store the processing conditions as necessary.

[0069] Note that the operation terminal 800 can be integrated into, for example, the marking controller 100. In this case, a name such as a control unit is used instead of "operation terminal", but at least in the present embodiment, the operation terminal 800 and the marking controller 100 are members independent of each other.

[0070] The external device 900 is connected to the marking controller 100 of the laser processing apparatus L as necessary. In the example shown, an image recognition device 901 and a programmable logic controller (PLC) 902 are provided as the external device 900. Figure 1

[0071] Specifically, the image recognition device 901 determines, for example, the type and position of the workpiece W conveyed on a production line. As the image recognition device 901, for example, an image sensor can be used. The PLC 902 is used to control the laser processing system S according to a predetermined sequence.

[0072] ​In addition to the above-mentioned devices and equipment, devices configured to perform operations and controls, computers configured to perform various other processes, storage devices, peripheral devices, etc. can be connected to the laser processing equipment L. In this case, the connection can be a serial connection such as IEEE1394, RS-232, RS-422 and USB, or a parallel connection. Alternatively, an electrical, magnetic or optical connection can be adopted via a network such as 10BASE-T, 100BASE-TX and 1000BASE-T. In addition to wired connections, wireless LANs such as IEEE802 and radio frequency waves such as Bluetooth (registered trademark), infrared or optical communications can also be used. For example, various memory cards, disks, magneto-optical disks, semiconductor memories, hard disks, etc. can be used as storage media for storage devices configured for data exchange and storage of various settings.

[0073] Hereinafter, the hardware configuration of each of the marking controller 100 and the marking head 1 and the configuration related to control of the marking head 1 by the marking controller 100 will be described in sequence.

[0074] <Marking Controller 100>

[0075] like Figure 2 As shown, the marking controller 100 includes: a condition setting storage unit 102, which stores processing conditions; a control unit 101, which controls the marking head 1 based on the processing conditions stored in the condition setting storage unit 102; and an excitation light generating unit 110, which generates laser excitation light (excitation light).

[0076] (Condition Setting Storage Unit 102)

[0077] The condition setting storage section 102 is configured to store processing conditions set using the operation terminal 800 and output the stored processing conditions to the control section 101 as needed.

[0078] Specifically, the condition setting storage unit 102 is constructed 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 processing conditions. When the operation terminal 800 is integrated into the marking controller 100, the storage device 803 can be configured to also function as the condition setting storage unit 102.

[0079] (Control Unit 101)

[0080] The control section 101 controls at least the excitation light generating section 110 in the marking controller 100, the laser output section 2, the laser guiding section 3, the laser scanning section 4, the distance measuring unit 5, the coaxial camera 6, and the wide-angle camera (non-coaxial camera) 7 in the marking head 1 based on the machining conditions stored in the condition setting storage section 102 to perform printing on the workpiece W.

[0081] Specifically, the control section 101 has a CPU, a memory, and an input / output bus, and generates a control signal based on a signal indicating information input via the operation terminal 800 and a signal indicating machining conditions read from the condition setting storage section 102. The control section 101 outputs the control signal thus generated to each section of the laser machining device L to control printing on the workpiece W and measurement of the distance to the workpiece W.

[0082] For example, when starting machining of the workpiece W, the control section 101 reads a target output stored in the condition setting storage section 102, outputs a control signal generated based on the target output to the excitation light source driving section 112, and controls generation of laser excitation light.

[0083] When actually machining the workpiece W, the control section 101 reads, for example, a machining pattern (marking pattern) stored in the condition setting storage section 102, outputs a control signal generated based on the machining pattern to the laser scanning section 4, and two-dimensionally scans near-infrared laser light.

[0084] In this way, the control section 101 can control the laser scanning section 4 so as to achieve two-dimensional scanning of near-infrared laser light. The control section 101 is an example of a “scanning control section” in the present embodiment.

[0085] (Excitation light generating section 110)

[0086] The excitation light generating section 110 includes an excitation light source 111 that generates laser light according to a driving current, an excitation light source driving section 112 that supplies the driving current to the excitation light source 111, and an excitation light condensing section 113 that is optically coupled to the excitation light source 111. The excitation light source 111 and the excitation light condensing section 113 are fixed in an excitation housing (not shown). Although not described in detail, the excitation housing is made of a metal such as copper that has excellent heat dissipation properties, and can effectively dissipate heat from the excitation light source 111.

[0087] Hereinafter, each section of the excitation light generating section 110 will be described in turn.

[0088] The excitation light source driving section 112 supplies the driving current to the excitation light source 111 based on a control signal output from the control section 101. Although not described in detail, the excitation light source driving section 112 determines the driving current based on a target output determined by the control section 101, and supplies the driving current thus determined to the excitation light source 111.

[0089] The excitation light source 111 is supplied with a drive current from the excitation light source drive section 112, and oscillates laser light in accordance with the drive current. For example, the excitation light source 111 is configured using a laser diode (LD) or the like, and an LD array or an LD bar in which a plurality of LD elements are linearly arranged can be used. When an LD array or an LD bar is used as the excitation light source 111, laser light oscillated from each element is output in a straight line and enters the excitation light condensing section 113.

[0090] The excitation light condensing section 113 collects laser light output from the excitation light source 111, and outputs the collected laser light as laser excitation light (excitation light). For example, the excitation light condensing section 113 is configured using a focusing lens or the like, and has an entrance surface for laser light to enter and an exit surface for laser excitation light to be output. The excitation light condensing section 113 is optically coupled to the marking head 1 via the optical fiber cable described above. Therefore, laser excitation light output from the excitation light condensing section 113 is guided to the marking head 1 via the optical fiber cable.

[0091] The excitation light generating section 110 can be configured as an LD unit or an LD module in which the excitation light source drive section 112, the excitation light source 111, and the excitation light condensing section 113 are integrated in advance. The excitation light emitted from the excitation light generating section 110 (specifically, laser excitation light output from the excitation light condensing section 113) can be unpolarized, and thus it is not necessary to take into account a change in polarization state, which is advantageous in terms of design. In particular, with regard to the configuration of the periphery of the excitation light source 111, it is preferable to provide a mechanism that makes the output light unpolarized in the LD unit itself that outputs light obtained from an LD array in which a plurality of LD elements are arranged in a bundle using an optical fiber.

[0092] (Other constituent elements)

[0093] The marking controller 100 also has a distance measuring section 103 that measures a distance to the workpiece W using the distance measuring unit 5. The distance measuring section 103 is electrically connected to the distance measuring unit 5, and can receive a signal related to the measurement result of the distance measuring unit 5 (at least, a signal indicating the light-receiving position of the distance measuring light in the distance measuring light-receiving section 5B).

[0094] As will be described later, the laser processing apparatus L according to the present embodiment also includes the on-axis camera 6 and the wide-angle camera 7 that is a non-on-axis camera. The laser processing apparatus L can capture the surface of the workpiece W by operating at least one of the on-axis camera 6 and the wide-angle camera 7.

[0095] The control section 101 in the marking controller 100 includes a feature quantity extraction section 105 and a position correction section 108 to perform processing based on an image captured by at least one of the on-axis camera 6 and the wide-angle camera 7.

[0096] The marking controller 100 further includes a setting section 107 that sets information about a mark pattern. The control section 101 that functions as a scan control section reads and uses the setting contents of the setting section 107.

[0097] Note that the control section 101 can be used to configure the distance measuring section 103, the feature amount extraction section 105, and the position correction section 108. For example, the control section 101 can also function as the position correction section 108. Further, the position correction section 108 can also function as the feature amount extraction section 105 or the like.

[0098] Details of the distance measuring section 103, the feature amount extraction section 105, the setting section 107, and the position correction section 108 will be described later.

[0099] <Marking head 1>

[0100] As described above, the laser excitation light generated by the excitation light generating section 110 is guided to the marking head 1 via the optical fiber cable. The marking head 1 includes a laser output section 2 that amplifies and generates laser light based on the laser excitation light and outputs the laser light, a laser scanning section 4 that irradiates the surface of the workpiece W with the laser light output from the laser output section 2 to perform two-dimensional scanning, a laser guide section 3 that forms an optical path from the laser output section 2 to the laser scanning section 4, a distance measuring unit 5 configured to measure a distance to the surface of the workpiece W based on distance measuring light projected and received through the laser scanning section 4, and a coaxial camera 6 and a wide-angle camera 7 that photograph the surface of the workpiece W.

[0101] Here, the laser guide section 3 according to the present embodiment not only forms an optical path but also combines with a plurality of members such as a Z scanner (focus adjustment section) 33 that adjusts the focal position of the laser light, a guide light source 36 from which guide light is emitted, the coaxial camera 6 that photographs the surface of the workpiece W, and the like.

[0102] The laser guide section 3 further includes an upstream-side confluence mechanism 31 that causes near-infrared laser light output from the laser output section 2 to confluence with guide light emitted from the guide light source 36, and a downstream-side confluence mechanism 35 that causes laser light guided to the laser scanning section 4 to confluence with distance measuring light projected from the distance measuring unit 5.

[0103] Figure 3A and Figure 3B is a block diagram showing a schematic configuration of the marking head 1, Figure 4 is a perspective view showing the appearance of the marking head 1. In Figures 3A-3B among them, Figure 3A a case in which the workpiece W is processed using near-infrared laser light is shown, Figure 3B a case in which the distance measuring unit 5 is used to measure a distance to the surface of the workpiece W is shown.

[0104] As Figures 3A-4As shown, the marking head 1 includes a housing 10 in which at least a laser output portion 2, a laser guide portion 3, a laser scanning portion 4, and a distance measuring unit 5 are provided. The housing 10 has a substantially rectangular outer shape as shown. Figure 4 A lower surface of the housing 10 is partitioned by a plate-shaped bottom plate 10a. The bottom plate 10a is provided with a light-transmitting window 19 configured to emit laser light from the marking head 1 to the outside of the marking head 1. The light-transmitting window 19 is configured by fitting a plate-shaped transparent member capable of transmitting near-infrared laser light, guide light, and distance measuring light into a through-hole that penetrates the bottom plate 10a in the plate thickness direction.

[0105] In the following description, Figure 4 the length direction of the housing 10 in the drawing is sometimes simply referred to as the "length direction" or the "front-rear direction", and the width direction of the housing 10 in the drawing is sometimes simply referred to as the "width direction" or the "left-right direction". Similarly, Figure 4 the height direction of the housing 10 in the drawing is sometimes simply referred to as the "height direction" or the "up-down direction".

[0106] Figure 5 is a perspective view showing the configuration of the laser scanning portion 4. Figure 6 is a cross-sectional view showing the configurations of the laser guide portion 3, the laser scanning portion 4, and the distance measuring portion 5, Figure 7 is a cross-sectional view showing the optical paths connecting the laser guide portion 3, the laser scanning portion 4, and the distance measuring unit 5, Figure 8 is a perspective view showing the optical paths connecting the laser guide portion 3, the laser scanning portion 4, and the distance measuring unit 5.

[0107] As shown in Figures 5-6 , a partition portion 11 is provided inside the housing 10. The internal space of the housing 10 is partitioned by the partition portion 11 into one side and the other side in the length direction.

[0108] Specifically, the partition portion 11 is formed in a flat plate shape extending in a direction perpendicular to the length direction of the housing 10. In the length direction of the housing 10, the partition portion 11 is disposed closer to the one side in the length direction (the front side in Figure 4 ) than to the central portion in the length direction of the housing 10.

[0109] Therefore, the space partitioned by the housing 10 on the one side in the length direction is shorter in the length direction than the space partitioned on the other side in the length direction (the rear side in Figure 4 ). Hereinafter, the space partitioned on the other side in the length direction inside the housing 10 is referred to as a first space S1, and the space partitioned on the one side in the length direction is referred to as a second space S2.

[0110] In the present embodiment, the laser output section 2, some components of the laser guide section 3, the laser scanning section 4, and the distance measuring unit 5 are arranged inside the first space S1. On the other hand, main components of the laser guide section 3 are arranged inside the second space S2.

[0111] Specifically, the first space S1 is divided by the substantially flat substrate 12 into a space on one side (left side in Figure 4 ) in the width direction and a space on the other side (right side in Figure 4 ) in the width direction. In the former space, components constituting the laser output section 2 are mainly arranged.

[0112] More specifically, among the components constituting the laser output section 2, optical members 21 such as optical lenses and optical crystals, which need to be hermetically sealed as much as possible, are arranged inside an accommodation space surrounded by the substrate 12 or the like in the space on one side in the width direction of the first space S1.

[0113] On the other hand, among the components constituting the laser output section 2, components such as electric wiring and Figure 5 heat sinks 22 shown in FIG. 2 or the like, which do not need to be sealed, are arranged on the opposite side to the optical members 21 (the other side in the width direction in the first space S1) of the substrate 12.

[0114] As shown in FIG. 2, Figure 5 and Figure 6 the laser scanning section 4 can be arranged on one side in the width direction of the substrate 12 as with the optical members 21 in the laser output section 2. Specifically, the laser scanning section 4 according to the present embodiment is adjacent to the partition 11 in the length direction and is arranged along the inner bottom surface of the housing 10 in the up-down direction.

[0115] As shown in FIG. 2, Figure 6 the distance measuring unit 5 is arranged in the space on the other side in the width direction of the first space S1 as with the heat sinks 22 in the laser output section 2.

[0116] In addition, components constituting the laser guide section 3 are mainly arranged in the second space S2. In the present embodiment, most of the components constituting the laser guide section 3 are accommodated in a space surrounded by the partition 11 and a cover member 17 defining the front surface of the housing 10.

[0117] Among the components constituting the laser guide section 3, the downstream-side flow combining mechanism 35 is arranged in the first space S1 at a position near the partition 11 (refer to Figure 5 ). That is, in the present embodiment, the downstream-side flow combining mechanism 35 is located at a position near the boundary between the first space S1 and the second space S2.

[0118] A through-hole (not shown) that penetrates the substrate 12 in the plate thickness direction is formed in the substrate 12. Through this through-hole, the laser guide section 3 and the laser scanning section 4 are optically coupled to the distance measuring unit 5.

[0119] Hereinafter, the configuration of the laser output section 2, the laser guide section 3, the laser scanning section 4, and the distance measuring unit 5 will be described in order.

[0120] (Laser output section 2)

[0121] The laser output section 2 is configured to generate near-infrared laser for printing based on laser excitation light generated by the laser excitation light generation section 110, and output the near-infrared laser for printing to the laser guide section 3.

[0122] Specifically, the laser output section 2 includes a laser oscillator 21a that generates laser having a predetermined wavelength based on the laser excitation light, amplifies the laser, and emits near-infrared laser, a beam sampler 21b configured to separate a portion of the near-infrared laser oscillated from the laser oscillator 21a, and a power monitor 21c into which the near-infrared laser separated by the beam sampler 21b is incident.

[0123] Although details are omitted, the laser oscillator 21a according to the present embodiment includes a laser medium that performs induced emission corresponding to the laser excitation light to emit laser, a Q-switch configured to pulse the laser emitted from the laser medium, and a mirror that resonates the laser pulsed by the Q-switch.

[0124] In particular, in the present embodiment, a rod-shaped Nd:YVO4 (yttrium vanadate) is used as the laser medium. As a result, the laser oscillator 21a can emit laser having a wavelength of around 1064 nm (the above-described near-infrared laser) as laser. However, not limited to this example, for example, YAG, YLF, GdVO4, and the like doped with rare earth can be used as other laser media. Various solid-state laser media can be used depending on the application of the laser processing apparatus L.

[0125] A solid-state laser medium can also be combined with a wavelength conversion element to convert the wavelength of the output laser to an arbitrary wavelength. In addition, a so-called fiber laser in which an optical fiber is used instead of a block as an oscillator can be used as the solid-state laser medium.

[0126] Further, the laser oscillator 21a can be configured by combining a solid-state laser medium such as Nd:YVO4 and an optical fiber. In this case, as in the case of using a solid-state laser medium, heat damage to the workpiece W can be suppressed by emitting laser having a short pulse width, and high output and faster printing can also be achieved in the case of using a fiber.

[0127] The power monitor 21c detects the output of the near-infrared laser light. The power monitor 21c is electrically connected to the marking controller 100, and can output its detection signal to the control section 101 or the like.

[0128] (laser guide section 3)

[0129] The laser guide section 3 forms at least a part of the laser path P that guides the near-infrared laser light emitted from the laser output section 2 to the laser scanning section 4. In addition to the bending mirror 34 configured to form the laser path P, the laser guide section 3 also includes a Z scanner (focal point adjustment section) 33, a guide light source (guide light emission section) 36, and the like. All of these components are disposed inside the housing 10 (mainly in the second space S2).

[0130] The near-infrared laser light that is incident from the laser output section 2 is reflected by the bending mirror 34 and passes through the laser guide section 3. The Z scanner 33 configured to adjust the focal point position of the near-infrared laser light is disposed on the way to the bending mirror 34. The near-infrared laser light that passes through the Z scanner 33 and is reflected by the bending mirror 34 is incident to the laser scanning section 4.

[0131] The laser path P formed by the laser guide section 3 can be divided into two parts with the Z scanner 33 as a boundary that is the focal point adjustment section. Specifically, the laser path P formed by the laser guide section 3 can be divided into an upstream side optical path Pu from the laser output section 2 to the Z scanner 33 and a downstream side optical path Pd from the Z scanner 33 to the laser scanning section 4.

[0132] More specifically, the upstream side optical path Pu is disposed inside the housing 10 and extends from the laser output section 2 to the Z scanner 33 after passing through the upstream side merging mechanism 31.

[0133] On the other hand, the downstream side optical path Pd is disposed inside the housing 10 and extends from the Z scanner 33 to the first scanner 41 in the laser scanning section 4 after sequentially passing through the bending mirror 34 and the downstream side merging mechanism 35.

[0134] In this way, inside the housing 10, the upstream side merging mechanism 31 is disposed midway through the upstream side optical path Pu, and the downstream side merging mechanism 35 is disposed midway through the downstream side optical path Pd.

[0135] Hereinafter, the configuration related to the laser guide section 3 will be explained sequentially.

[0136] -Guide light source 36-

[0137] The guide light source 36 is disposed in the second space S2 inside the housing 10, and emits guide light configured to project a predetermined processing pattern onto the surface of the workpiece W. The wavelength of the guide light is set to fall within the visible light range. As an example thereof, the guide light source 36 according to the present embodiment emits red laser light having a wavelength around 655 nm as the guide light. Thus, when the guide light is emitted from the marking head 1, the user can visually recognize the guide light.

[0138] In the present embodiment, the wavelength of the guide light is set to be different from at least the wavelength of the near-infrared laser light. As described later, the ranging light emission section 5A of the ranging unit 5 emits ranging light having a wavelength different from those of the guide light and the near-infrared laser light. Thus, the ranging light, the guide light, and the laser light have wavelengths different from each other.

[0139] Specifically, the guide light source 36 is configured at substantially the same height as the upstream-side coalescence mechanism 31 in the second space S2, and can emit visible laser light (guide light) toward the inner side of the housing 10 in the width direction. The guide light source 36 is also configured so that the optical axis of the guide light emitted from the guide light source 36 intersects the upstream-side coalescence mechanism 31.

[0140] Note that "substantially the same height" here means a height position substantially the same as the height observed from the bottom plate 10a that forms the lower surface of the housing 10. In other descriptions, the height means the height observed from the bottom plate 10a.

[0141] For example, when the guide light is emitted from the guide light source 36 so that the user can visually recognize the processing pattern of the near-infrared laser light, the guide light reaches the upstream-side coalescence mechanism 31. The upstream-side coalescence mechanism 31 has a dichroic mirror (not shown) as an optical member. As described later, the dichroic mirror reflects the near-infrared laser light while transmitting the guide light. As a result, the guide light that has passed through the dichroic mirror and the near-infrared laser light that has been reflected by the same mirror become coaxial by coalescing with each other.

[0142] Note that the guide light source 36 according to the present embodiment is configured to emit the guide light based on a control signal output from the control section 101.

[0143] - Upstream-side coalescence mechanism 31 -

[0144] The upstream-side coalescence mechanism 31 coalesces the guide light emitted from the guide light source 36 that is the guide light emission section with the upstream-side optical path Pu. Because the upstream-side coalescence mechanism 31 is provided, it is possible to make the guide light emitted from the guide light source 36 coaxial with the near-infrared laser light on the upstream-side optical path Pu.

[0145] 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, the upstream-side merging mechanism 31 can be configured using, for example, a dichroic mirror as described above. The near-infrared laser light and the guide light, which have been coaxialized by the dichroic mirror, propagate downward, pass through the Z scanner 33, and reach the folding mirror 34.

[0146] Z scanner 33

[0147] The Z scanner 33, which is a focal point adjustment section, is disposed in the middle of an optical path formed by the laser guide section 3, and is capable of adjusting a focal point position of the near-infrared laser light emitted from the laser output section 2.

[0148] Specifically, in the laser path P within the housing 10, the Z scanner 33 is disposed in the middle of an optical path from the upstream-side merging mechanism 31, which is a guide light merging mechanism, to the laser scanning section 4.

[0149] Specifically, as shown in Figures 3A-3B , the Z scanner 33 according to the present embodiment includes: an input lens 33a that transmits the near-infrared laser light emitted from the laser output section 2; a collimator lens 33b that transmits the near-infrared laser light that has passed through the input lens 33a; an output lens 33c that transmits the near-infrared laser light that has passed through the input lens 33a and the collimator lens 33b; a lens drive section 33d that moves the input lens 33a; and a housing 33e that accommodates the input lens 33a, the collimator lens 33b, and the output lens 33c.

[0150] The input lens 33a is a plano-concave lens, and the collimator lens 33b and the output lens 33c are plano-convex lenses. The input lens 33a, the collimator lens 33b, and the output lens 33c are disposed in a manner that the optical axes thereof are coaxial with each other.

[0151] In the Z scanner 33, the lens drive section 33d moves the input lens 33a along the optical axis. As a result, it is possible to change the relative distance between the input lens 33a and the output lens 33c while maintaining the respective optical axes of the input lens 33a, the collimator lens 33b, and the output lens 33c coaxial with respect to the near-infrared laser light passing through the Z scanner 33. As a result, the focal point position of the near-infrared laser light irradiating the workpiece W is changed.

[0152] Hereinafter, each part of the Z scanner 33 will be described in more detail.

[0153] The housing 33e is substantially cylindrical. As shown in Figure 3A and Figure 3B , openings 33f configured to pass the near-infrared laser light are formed at both ends of the housing 33e. Inside the housing 33e, the input lens 33a, the collimator lens 33b, and the output lens 33c are arranged in series in the up-down direction.

[0154] Among the input lens 33a, the collimator lens 33b, and the output lens 33c, the collimator lens 33b and the output lens 33c are fixed inside the housing 33e. On the other hand, the input lens 33a is provided so as to be movable in the up-down direction. The lens driving section 33d has, for example, a motor and moves the input lens 33a in the up-down direction. As a result, the relative distance between the input lens 33a and the output lens 33c is changed.

[0155] For example, assume that the distance between the input lens 33a and the output lens 33c is adjusted to be relatively short by the lens driving section 33d. In this case, the light collection angle of the near-infrared laser light passing through the output lens 33c is relatively small, and therefore, the focal point position of the near-infrared laser light is moved away from the light-transmitting window 19 of the marking head 1.

[0156] On the other hand, assume that the distance between the input lens 33a and the output lens 33c is adjusted to be relatively long by the lens driving section 33d. In this case, the light collection angle of the near-infrared laser light passing through the output lens 33c is relatively large, and therefore, the focal point position of the near-infrared laser light is close to the light-transmitting window 19 of the marking head 1.

[0157] Note that the input lens 33a can be fixed inside the housing 33e, and among the input lens 33a, the collimator lens 33b, and the output lens 33c in the Z scanner 33, the collimator lens 33b and the output lens 33c can be movable in the up-down direction. Alternatively, the input lens 33a, the collimator lens 33b, and the output lens 33c can all be movable in the up-down direction.

[0158] In this way, the Z scanner 33 as the focal point adjusting section functions as a mechanism configured to scan the near-infrared laser light in the up-down direction. Hereinafter, the scanning direction of the Z scanner 33 is sometimes referred to as the "Z direction".

[0159] 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, it is possible to adjust not only the focal point position of the near-infrared laser light but also the focal point position of the guide light.

[0160] Note that the Z scanner 33 according to the present embodiment (particularly the lens driving section 33d in the Z scanner 33) is configured to operate based on a control signal output from the control section 101.

[0161] - Bending mirror 34 -

[0162] The bending mirror 34 is provided midway through the downstream side light path Pd and is configured to bend the light path Pd toward the rear side. As described above, the guide light emitted from the guide light source 36 is coaxial with the near-infrared laser light emitted from the near-infrared laser source 31. Therefore, the guide light emitted from the guide light source 36 is also bent by the bending mirror 34. Figure 6As shown, the bending mirror 34 is arranged at substantially the same height as the optical member 35 a 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 .

[0163] The near-infrared laser light and the guide light reflected by the bending mirror 34 propagate backward, pass through the downstream-side merging mechanism 35 , and reach the laser scanning section 4 (specifically, reach the first scanner 41 ).

[0164] - Downstream side merging mechanism 35 -

[0165] The downstream merging mechanism 35 merges the distance measuring light emitted from the distance measuring light emitting portion 5A in the distance measuring unit 5 with the downstream optical path Pd and guides the distance measuring light toward the workpiece W via the laser scanning unit 4. Furthermore, the downstream merging mechanism 35 guides the distance measuring light reflected by the workpiece W and sequentially returned to the laser scanning unit 4 and the downstream optical path Pd to the distance measuring light receiving portion 5B in the distance measuring unit 5.

[0166] The downstream merging mechanism 35 allows the distance-measuring light emitted from the distance-measuring light emitting section 5A to be coaxial with the near-infrared laser light and the guide light in the downstream optical path Pd. Furthermore, the downstream merging mechanism 35 allows the distance-measuring light emitted from the marking head 1 and reflected by the workpiece W, which then enters the marking head 1, to be guided to the distance-measuring light receiving section 5B.

[0167] As described above, the wavelength of the distance measuring light is set to be different from the wavelengths of the near-infrared laser light and the guide light. Therefore, similarly to the upstream merging mechanism 31, the downstream merging mechanism 35 can be constructed by using, for example, a dichroic mirror.

[0168] Specifically, the downstream side merging mechanism 35 according to the present embodiment has a dichroic mirror 35a that transmits one of the distance measuring light and the guide light and reflects the other (see FIG. Figure 6 and Figure 7 ). More specifically, the dichroic mirror 35 a is arranged at substantially the same height as the bending mirror 34 on the rear side of the bending mirror 34 and is arranged in a space on the left side of the housing 10 in the width direction.

[0169] like Figure 6 As shown in FIG. 1 and FIG. 2 , the dichroic mirror 35a is fixed with one mirror surface facing the bending mirror 34 and the other mirror surface facing the substrate 12. Therefore, the near-infrared laser light and the guide light are incident on the mirror surface on one side of the dichroic mirror 35a, and the distance measuring light is incident on the mirror surface on the other side.

[0170] The dichroic mirror 35a according to the present embodiment can reflect the ranging light and transmit the near-infrared laser light and the guide light. As a result, for example, when the ranging light emitted from the ranging unit 5 is incident on the dichroic mirror 35a, the ranging light can be made to converge with the downstream-side light path Pd, thereby being coaxial with the near-infrared laser light and the guide light. The near-infrared laser light, the guide light, and the ranging light that have been coaxialized in this way reach the first scanner 41, as shown in Figure 3A and Figure 3B .

[0171] Meanwhile, the ranging light that has been reflected by the workpiece W returns to the laser scanning section 4 and reaches the downstream-side light path Pd. The ranging light that has returned to the downstream-side light path Pd is reflected by the dichroic mirror 35a in the downstream-side converging mechanism 35 to reach the ranging unit 5.

[0172] Note that, when the housing 10 is observed in a plan view as shown in Figure 7 , the ranging light that is incident on the dichroic mirror 35a from the ranging unit 5 and the ranging light that is reflected by the dichroic mirror 35a and is incident on the ranging unit 5 propagate along the left-right direction (the width direction of the housing 10).

[0173] (Laser scanning section 4)

[0174] As shown in Figure 3A , the laser scanning section 4 is configured to irradiate the workpiece W with the laser light (near-infrared laser light) that is emitted from the laser output section 2 and guided by the laser guide section 3, and perform two-dimensional scanning on the surface of the workpiece W.

[0175] In the example shown in Figure 5 , the laser scanning section 4 is configured as a so-called biaxial galvanometer scanner. That is, the laser scanning section 4 includes a first scanner 41 configured to scan the near-infrared laser light that is incident from the laser guide section 3 in a first direction, and a second scanner 42 configured to scan the near-infrared laser light that is scanned by the first scanner 41 in a second direction.

[0176] Here, the second direction indicates a direction that is substantially orthogonal to the first direction. Thus, the second scanner 42 can scan the near-infrared laser light in a direction that is substantially orthogonal to the first scanner 41. In the present embodiment, the first direction is equal to the front-rear direction (the length direction of the housing 10), and the second direction is equal to the left-right direction (the width direction of the housing 10). Hereinafter, the first direction is referred to as the "X direction", and the second direction that is orthogonal to the first direction is referred to as the "Y direction". Both the X direction and the Y direction are orthogonal to the above-described Z direction.

[0177] The first scanner 41 has a first mirror 41a at the distal end thereof. The first mirror 41a is disposed at substantially the same height as the bending mirror 34 and the optical member 35a on the rear side of the optical member 35a. As shown in Figure 5As shown, the bending mirror 34, the optical member 35a, and the first mirror 41a are aligned in a row along the front-rear direction (the length direction of the housing 10).

[0178] In addition, the first mirror 41a is rotationally driven by a motor (not shown) built in the first scanner 41. This motor can rotate the first mirror 41a about a rotational axis extending in the up-down direction. The reflection angle of the near-infrared laser light reflected by the first mirror 41a can be adjusted by adjusting the rotational posture of the first mirror 41a.

[0179] Likewise, the second scanner 42 has a second mirror 42a at its distal end. The second mirror 42a is disposed at substantially the same height as the first mirror 41a on the right side of the first mirror 41a in the first scanner 41. As shown, Figure 6 As shown, the first mirror 41a and the second mirror 42a are aligned in a row along the left-right direction (the width direction of the housing 10).

[0180] In addition, the second mirror 42a is rotationally driven by a motor (not shown) built in the second scanner 42. This motor can rotate the second mirror 42a about a rotational axis extending in the front-rear direction. The reflection angle of the near-infrared laser light reflected by the second mirror 42a can be adjusted by adjusting the rotational posture of the second mirror 42a.

[0181] When the near-infrared laser light is incident on the laser scanning section 4 from the downstream-side combining mechanism 35, the near-infrared laser light is sequentially reflected by the first mirror 41a in the first scanner 41 and the second mirror 42a in the second scanner 42, and is emitted to the outside of the marking head 1 via the light-transmitting window 19.

[0182] At this time, by adjusting the rotational posture of the first mirror 41a by operating the motor of the first scanner 41, the near-infrared laser light can be scanned in the first direction on the surface of the workpiece W. Meanwhile, by adjusting the rotational posture of the second mirror 42a by operating the motor of the second scanner 42, the near-infrared laser light can be scanned in the second direction on the surface of the workpiece W.

[0183] As described above, not only the near-infrared laser light, but also the guide light that has passed through the optical member 35a of the downstream-side combining mechanism 35 or the ranging light that is reflected by the same member 35a is incident on the laser scanning section 4. The laser scanning section 4 according to the present embodiment can perform two-dimensional scanning of the guide light or the ranging light that is incident in this manner by respectively operating the first scanner 41 and the second scanner 42.

[0184] The rotational postures that the first mirror 41a and the second mirror 42a can take are substantially set within a range that allows the reflected light to pass through the light-transmitting window 19 when the near-infrared laser light is reflected by the second mirror 42a (see also Figures 7-8 ).

[0185] In this way, the laser scanning section 4 according to the present embodiment is electrically controlled by the control section 101 as a scanning control section, and is able to irradiate the processing region R1 set on the surface of the workpiece W with near-infrared laser light to form a predetermined processing pattern (mark pattern) in the processing region R1.

[0186] (Coaxial camera 6)

[0187] The coaxial camera 6 has an imaging optical axis Al that branches from the laser path P from the laser output section 2 to the laser scanning section 4 (refer to FIG. 2). Figure 3A and Figure 3B The coaxial camera 6 can capture an image of the workpiece W with the laser scanning section 4 to generate a captured image Pw that includes at least a part of the processing region R1. The coaxial camera 6 is an example of a "first imaging section" in the present embodiment.

[0188] The coaxial camera 6 is configured as an imaging mechanism that is coaxial with the near-infrared laser for processing. The coaxial camera 6 has a narrower field of view than the wide-angle camera 7, but can generate a coaxial image in which the processing region R1 is enlarged at a relatively high magnification compared to the captured image Pw, and can two-dimensionally scan an imaging region with the laser scanning section 4. The coaxial camera 6 is used, for example, to locally enlarge and capture a part of the processing region R1.

[0189] The captured image Pw generated by the coaxial camera 6 can be displayed on the display section 801 in a state in which at least a part thereof is enlarged or reduced.

[0190] The coaxial camera 6 according to the present embodiment is built into the housing 10. Specifically, the coaxial camera 6 is disposed at substantially the same height as the bending mirror 34 in the laser light guide section 3. The coaxial camera 6 receives reflected light that is incident to the laser guide section 3 from the laser scanning section 4. The coaxial camera 6 is configured so that reflected light that is reflected at a printing point of the workpiece W enters via the bending mirror 34. The coaxial camera 6 can form an image of the reflected light that thus enters, thereby capturing the surface of the workpiece W. Note that the layout of the coaxial camera 6 can be changed as appropriate. For example, the heights of the coaxial camera 6 and the bending mirror 34 can be different from each other.

[0191] The reflected light for imaging of the coaxial camera 6 branches from the downstream-side light path Pd and propagates. Therefore, Figure 12 The processing region R1 illustrated can be two-dimensionally scanned by appropriate operation of the laser scanning section 4.

[0192] As with the guide light source 36 and the like, the coaxial camera 6 according to the present embodiment is configured to operate based on a control signal output from the control section 101.

[0193] (Wide-angle camera 7)

[0194] The wide-angle camera 7 has an imaging optical axis A2 branched from the laser path P (refer to Figure 12 ). The wide-angle camera 7 can capture the workpiece W without the laser scanning section 4 to generate a captured image Pw having a wider image field of view than the image generated by the coaxial camera 6. The wide-angle camera 7 is an example of the "second imaging section" in the present embodiment.

[0195] The wide-angle camera 7 is configured as an imaging mechanism that is not coaxial with the near-infrared laser for processing. The wide-angle camera 7 cannot perform two-dimensional scanning using the laser scanning section 4, but has a wider field of view than the coaxial camera 6, and can generate a wide-angle image obtained by capturing the processing region R1 as a captured image Pw in a relatively wide field of view. The wide-angle camera 7 is used, for example, to capture the entire processing region R1 at a time.

[0196] The captured image Pw generated by the wide-angle camera 7 can be displayed on the display section 801 in a state in which at least a part thereof is enlarged or reduced. The display section 801 can display the captured image Pw generated by the wide-angle camera 7 and the captured image Pw generated by the coaxial camera 6 in parallel, or selectively display one of the two types of captured images Pw.

[0197] The wide-angle camera 7 according to the present embodiment is disposed directly above the light-transmitting window 19 and fixed in a posture in which the imaging lens of the wide-angle camera 7 faces downward. As described above, the imaging optical axis A2 of the wide-angle camera 7 is not coaxial with the optical axis Az of the above-described near-infrared laser (refer to Figure 3A 、 Figure 3B and Figure 12 ).

[0198] Note that the "imaging section" according to the present embodiment includes at least one of the coaxial camera 6 as the first imaging section and the wide-angle camera 7 as the second imaging section. That is, the captured image Pw generated by the coaxial camera 6 or the wide-angle camera 7 is used for the control described later, and the captured image Pw can be described using either the coaxial camera 6 or the wide-angle camera 7, or both of them in combination. The configuration including both the coaxial camera 6 and the wide-angle camera 7 is not essential.

[0199] (Ranging unit 5)

[0200] As shown in Figure 3B , the ranging unit 5 projects ranging light via the laser scanning section 4 and irradiates the surface of the workpiece W with the ranging light. The ranging unit 5 also receives the ranging light reflected by the surface of the workpiece W via the laser scanning section 4.

[0201] The distance measuring unit 5 is mainly divided into a distance measuring light projecting module and a distance measuring light receiving module. Specifically, the distance measuring unit 5 includes a distance measuring light emitting portion 5A configured as the distance measuring light projecting module, and a distance measuring light receiving portion 5B configured as the distance measuring light receiving module.

[0202] The distance measuring light emitting portion 5A is disposed inside the housing 10 and emits distance measuring light for measuring a distance from the marking head 1 to the surface of the workpiece W in the laser processing apparatus L toward the laser scanning portion 4.

[0203] On the other hand, the distance measuring light receiving portion 5B is also disposed inside the housing 10 as the distance measuring light emitting portion 5A, and receives distance measuring light that has been reflected on the surface of the workpiece W and returned via the laser scanning portion 4 and the downstream-side co-current mechanism 35.

[0204] In addition, the distance measuring unit 5 includes a support base 50 that supports the distance measuring light emitting portion 5A and the distance measuring light receiving portion 5B from below, and the distance measuring unit 5 is fixed to the inside of the housing 10 via the support base 50.

[0205] As described above, the distance measuring unit 5 is disposed in a space on the other side in the width direction of the first space S1. As shown in FIG. 1, the distance measuring unit 5 emits distance measuring light forward along the length direction of the housing 10 and receives distance measuring light that propagates substantially backward along the length direction. Figure 7

[0206] The distance measuring unit 5 is optically coupled to the laser guide portion 3 via the above-described optical member 35a. As described above, the distance measuring unit 5 projects distance measuring light along the length direction of the housing 10. On the other hand, the optical member 35a is configured to reflect distance measuring light that propagates along the width direction of the housing 10 rather than the length direction.

[0207] Therefore, the bending mirror 59 is disposed inside the housing 10 in a manner to form an optical path connecting the distance measuring unit 5 and the optical member 35a (refer to FIG. 1). Figure 6 and Figure 7

[0208] Therefore, distance measuring light that is incident to the bending mirror 59 from the distance measuring light emitting portion 5A is reflected by the same mirror 59 to be incident to the optical member 35a. On the other hand, distance measuring light that returns to the laser scanning portion 4 and is reflected by the optical member 35a is incident to the bending mirror 59 and is reflected by the same mirror 59 to be incident to the distance measuring light receiving portion 5B.

[0209] Hereinafter, the configuration of each portion of the distance measuring unit 5 will be described in order.

[0210] - Distance Measuring Light Emitting Portion 5A -

[0211] ​​The distance measuring light exit portion 5A is provided inside the housing 10 and is configured to exit distance measuring light for measuring a distance from the marking head 1 to a surface of the workpiece W in the laser processing apparatus L.

[0212] Specifically, the distance measuring light exit portion 5A includes a distance measuring light source 51 and a light projecting lens 52, a housing 53 that houses the distance measuring light source 51 and the light projecting lens 52, and a pair of guide plates 54L and 54R that guide distance measuring light collected by the light projecting lens 52. The distance measuring light source 51, the light projecting lens 52, and the guide plates 54L and 54R are arranged in this order from the rear side of the housing 10, and the arrangement direction thereof is substantially the same as the length direction of the housing 10.

[0213] The housing 53 is formed in a cylindrical shape extending along the length direction of the housing 10 and the support base 50, the distance measuring light source 51 is mounted to one side in the length direction, that is, to one end corresponding to the rear side of the housing 10, and the light projecting lens 52 is mounted to the other end corresponding to the front side of the housing 10. The space between the distance measuring light source 51 and the light projecting lens 52 is sealed in a substantially airtight manner.

[0214] The distance measuring light source 51 emits distance measuring light toward the front side of the housing 10 in accordance with a control signal input from the control portion 101. Specifically, the distance measuring light source 51 can emit laser light in the visible light range as distance measuring light. In particular, the distance measuring light source 51 according to the present embodiment emits red laser light having a wavelength of around 690 nm as distance measuring light.

[0215] In addition, the distance measuring light source 51 is fixed in a posture in which the optical axis Ao of the red laser light emitted as distance measuring light extends along the length direction of the housing 53. Therefore, the optical axis Ao of the distance measuring light extends along the length direction of the housing 10 and the support base 50, passes through the central portion of the light projecting lens 52, and reaches the outside of the housing 53.

[0216] The light projecting lens 52 is located between the light receiving lens 57 and the pair of light receiving elements 56L and 56R in the distance measuring light receiving portion 5B in the length direction of the support base 50. The light projecting lens 52 is provided in a posture that allows the optical axis Ao of the distance measuring light to pass therethrough.

[0217] The light projecting lens 52 can be, for example, a plano-convex lens, and the spherical convex surface can be fixed in a posture facing the outside of the housing 53. The light projecting lens 52 collects distance measuring light emitted from the distance measuring light source 51 and emits the distance measuring light to the outside of the housing 53. The distance measuring light emitted to the outside of the housing 53 reaches between the guide plates 54L and 54R.

[0218] The guide plates 54L and 54R are configured as a pair of members arranged in the width direction of the support base 50, and each of the guide plates 54L and 54R can be a plate-shaped member extending in the length direction of the support base 50. A space for emitting the ranging light is defined between one guide plate 54L and the other guide plate 54R. The ranging light emitted to the outside of the casing 53 passes through the space thus partitioned and is output.

[0219] Therefore, the ranging light emitted from the ranging light source 51 passes through the space inside the casing 53, the central portion of the light projecting lens 52, and the space between the guide plates 54L and 54R, and is output to the outside of the ranging unit 5. The ranging light thus output is reflected by the optical member 35a in the downstream side coalescing mechanism 35 and the bending mirror 59, and is incident on the laser scanning section 4.

[0220] The ranging light incident on the laser scanning section 4 is sequentially reflected by the first mirror 41a of the first scanner 41 and the second mirror 42a of the second scanner 42, and is emitted to the outside of the marking head 1 from the light-transmitting window 19.

[0221] As explained in the explanation of the laser scanning section 4, the ranging light can be scanned on the surface of the workpiece W in the first direction by adjusting the rotational attitude of the first mirror 41a of the first scanner 41. Meanwhile, the ranging light can be scanned on the surface of the workpiece W in the second direction by operating the motor of the second scanner 42 to adjust the rotational attitude of the second mirror 42a.

[0222] The ranging light thus scanned is reflected on the surface of the workpiece W. Part of the ranging light thus reflected (hereinafter, also referred to as "reflected light") is incident on the inside of the marking head 1 through the light-transmitting window 19. The reflected light having been incident on the inside of the marking head 1 is returned to the laser guiding section 3 via the laser scanning section 4. The reflected light has the same wavelength as the ranging light, and therefore, the reflected light is reflected by the optical member 35a of the downstream side coalescing mechanism 35 in the laser guiding section 3 and is incident on the ranging unit 5 via the bending mirror 59.

[0223] - Ranging light light-receiving section 5B -

[0224] The ranging light light-receiving section 5B is provided inside the housing 10, and is configured to receive the ranging light (equivalent to the "reflected light" explained above) emitted from the ranging light emitting section 5A and reflected by the workpiece W.

[0225] Specifically, the ranging light light-receiving section 5B has a pair of light-receiving elements 56L and 56R and a light-receiving lens 57. Respectively, the pair of light-receiving elements 56L and 56R are each disposed at the rear end portion of the support base 50, and the light-receiving lens 57 is disposed at the front end portion of the support base 50. Therefore, the pair of light-receiving elements 56L and 56R and the light-receiving lens 57 are substantially arranged in the length direction of the housing 10 and the support base 50.

[0226] The pair of light receiving elements 56L and 56R are arranged inside the housing 10 in a manner that their respective optical axes sandwich the optical axis Ao of the ranging light in the ranging light exit portion 5A. Both of the pair of light receiving elements 56L and 56R receive the reflected light that has returned to the laser scanning portion 4.

[0227] Specifically, the pair of light receiving elements 56L and 56R are arranged in a direction orthogonal to the optical axis Ao of the ranging light exit portion 5A. In the present embodiment, the arrangement direction of the pair of light receiving elements 56L and 56R is equal to the width direction (i.e., the left-right direction) of the housing 10 and the support base 50. In the same direction, one light receiving element 56L is arranged on the left side of the ranging light source 51, and the other light receiving element 56R is arranged on the right side of the ranging light source 51.

[0228] The pair of light receiving elements 56L and 56R have light receiving surfaces that respectively face obliquely forward, and detect the light receiving positions of the reflected light on the respective light receiving surfaces, and output signals (detection signals) that represent the detection results. The detection signals output from the respective light receiving elements 56L and 56R are input to the marking controller 100 and reach the ranging portion 103.

[0229] Examples of elements that can be used as the light receiving elements 56L and 56R include a CMOS image sensor formed of a complementary MOS (CMOS), a CCD image sensor formed of a charge-coupled device (CCD), a position sensitive detector (PSD), and the like.

[0230] In the present embodiment, a CMOS image sensor is used to configure each of the light receiving elements 56L and 56R. In this case, both of the light receiving elements 56L and 56R can detect not only the light receiving positions of the reflected light, but also the light receiving amount distribution (light receiving waveform) of the reflected light. That is, when a CMOS image sensor is used to configure each of the light receiving elements 56L and 56R, the pixels are arranged on the respective light receiving surfaces in at least the left-right direction. In this case, both of the light receiving elements 56L and 56R can read and amplify the signals of the respective pixels, and output the signals to the outside. When a light spot is formed on the light receiving surface by the reflected light, the intensity of the signal in each pixel is determined based on the intensity of the reflected light at the light spot.

[0231] When each of the light receiving elements 56L and 56R is configured using an element such as a CMOS image sensor that is capable of detecting the light receiving amount distribution (light receiving waveform), the light receiving amount size in each of the light receiving elements 56L and 56R can be adjusted using the intensity of the ranging light (i.e., the intensity of the ranging light that exits from the ranging light exit portion 5A (hereinafter, this is also referred to as the “projected light amount”) and the gain at which the signals for the respective pixels are amplified (hereinafter, this is also referred to as the “light receiving gain”). In addition to the gain, the exposure time of each of the light receiving elements 56L and 56R can be used for adjustment.

[0232] The pair of light-receiving elements 56L and 56R according to the present embodiment can detect at least the peak position of the light-receiving position of the reflected light and the light-receiving amount of the reflected light. As an index indicating the light-receiving amount, for example, the height of the peak in the light-receiving amount distribution of the reflected light can be used. Alternatively, the total value, the average value, and the integral value of the light-receiving amount distribution can be used.

[0233] In the present embodiment, although the peak position of the light-receiving amount distribution (the peak position of the light spot) is used as an index indicating the light-receiving position of the reflected light, the center of gravity position of the light-receiving amount distribution can be used instead.

[0234] The light-receiving lens 57 is arranged inside the housing 10 to allow the optical axis of each of the pair of light-receiving elements 56L and 56R to pass therethrough. The light-receiving lens 57 is also provided on the way of the optical path connecting the downstream-side coalescing mechanism 35 and the pair of light-receiving elements 56L, 56R, and is capable of condensing the reflected light that has passed through the downstream-side coalescing mechanism 35 on the light-receiving surface of each of the pair of light-receiving elements 56L and 56R.

[0235] The light-receiving lens 57 condenses the reflected light that returns to the laser scanning section 4 and forms a light spot of the reflected light on the light-receiving surface of each of the light-receiving elements 56L and 56R. Each of the light-receiving elements 56L and 56R outputs a signal indicating the peak position and the light-receiving amount of the light spot thus formed to the distance measuring section 103.

[0236] Basically, the laser processing apparatus L can 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 and 56R (the peak position of the light spot in the present embodiment). The so-called triangulation method is used as the distance measurement method.

[0237] - About the distance measurement method -

[0238] Figure 9 is a diagram showing the triangulation method. Although Figure 9 Only the distance measuring unit 5 is shown, but the following explanation is the same as the case where the distance measuring light is emitted via the laser scanning section 4 as described above.

[0239] As Figure 9 shown, when the distance measuring light is emitted from the distance measuring light source 51 in the distance measuring light emission section 5A, the surface of the workpiece W is irradiated with the distance measuring light. When the distance measuring light is reflected by the workpiece W, if the influence of the specular reflection is eliminated, the reflected light (particularly, the diffuse reflected light) propagates isotropically.

[0240] Although the reflected light propagated in this way contains a component that is incident on the light-receiving element 56L via the light-receiving lens 57, the incident angle of the incident light to the light-receiving element 56L increases or decreases depending on the distance between the marking head 1 and the workpiece W. When the incident angle with respect to the light-receiving element 56L increases or decreases, the light-receiving position on the light-receiving surface 56a shifts.

[0241] In this way, the distance between the marking head 1 and the workpiece W and the light-receiving position on the light-receiving surface 56a are associated with each other in a predetermined relationship. Therefore, when this relationship is grasped in advance and stored in the marking controller 100, for example, the distance between the marking head 1 and the workpiece W can be calculated from the light-receiving position on the light-receiving surface 56a. This calculation method is a method using so-called triangulation.

[0242] That is, the distance measuring section 103 measures the distance from the laser processing apparatus L to the surface of the workpiece W by triangulation based on the light-receiving position of the distance measuring light in the distance measuring light-receiving section 5B.

[0243] Specifically, the condition setting storage section 102 stores in advance the relationship between the light-receiving position on the light-receiving surface 56a and the distance from the marking head 1 to the surface of the workpiece W. On the other hand, a signal indicating the light-receiving position of the distance measuring light in the distance measuring light-receiving section 5B (specifically, the position of the peak of the light spot formed on the light-receiving surface 56a by the reflected light of the distance measuring light) is input to the distance measuring section 103.

[0244] The distance measuring section 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 section 102. The measurement value thus obtained is input to, for example, the control section 101, and is used by the control section 101 in order to control the Z scanner 33 or the like.

[0245] For example, the laser processing apparatus L determines the site (print point) on the surface of the workpiece W to be processed by the marking head 1 automatically or manually. Subsequently, the laser processing apparatus L measures the distance to each print point (more accurately, a distance measuring point set around the print point) before performing printing, and determines the control parameter of the Z scanner 33 so that the focal position corresponds to the measured distance. The laser processing apparatus L operates the Z scanner 33 based on the control parameter thus determined, and then performs printing on the workpiece W with near-infrared laser light.

[0246] Hereinafter, a specific use method of the laser processing system S will be described.

[0247] <Method of using the laser processing system S>

[0248] Figure 10 is a flowchart showing the use method of the laser processing system S. Figure 11 is a flowchart showing the process of creating a print setting, a search setting, and a distance measuring setting,Figure 12 is a diagram showing a relationship between the processing region R1 and the set surface R4, Figure 13 is a diagram showing display content on the display section 801.

[0249] Figures 14A-14D is a diagram showing a specific procedure for setting a search condition, Figures 15A-15D is a diagram showing a specific procedure for setting a ranging condition, Figure 16 is a flowchart showing an operation procedure of the laser processing apparatus L, Figures 17A-17D is a diagram showing a specific procedure for pattern search, Figure 18 is a diagram for explaining trapezoidal correction, Figure 19 is a diagram showing a relationship between misalignment of a workpiece and a focal point position.

[0250] The laser processing system S including the laser processing apparatus L configured as a laser marker can be installed and operated on a production line of a factory, for example. At the time of operation, first, a condition setting (step S1) such as a mounting position of a workpiece W flowing through the production line and each output of near-infrared laser and ranging light irradiating the workpiece W is created before operation of the production line.

[0251] The setting content created in step S1 is transmitted and stored in the marking controller 100 and / or the operation terminal 800, or is read by the marking controller 100 immediately after creation (step S2).

[0252] Then, when the production line is operated, the marking controller 100 refers to the setting content stored in advance or the setting content read immediately after creation. The laser processing apparatus L is operated based on the referred setting content, and performs printing on each workpiece W flowing on the production line (step S3).

[0253] (Specific creation procedure of each setting)

[0254] Figure 11 The specific processing in step S1 of Figure 10 is shown. As shown in Figure 11 , in the present embodiment, a control procedure related to printing setting, a control procedure related to search setting, and a control procedure related to ranging setting are sequentially executed. Each control procedure is configured as an independent procedure which does not overlap with each other.

[0255] First, in step S11, the coaxial camera 6 or the wide-angle camera 7 built in the laser processing apparatus L generates a captured image Pw including at least a part of the processing region R1. The captured image Pw generated by the coaxial camera 6 or the wide-angle camera 7 is output to the operation terminal 800.

[0256] The display section 801 of the operation terminal 800 displays the setting surface R4 associated with the processing region R1, and also displays the captured image Pw on the setting surface R4 (refer to Figure 13 ). As a result, the coordinate system defined on the setting surface R4 in the display section 801 (print coordinate system) and the coordinate system defined on the captured image Pw (camera coordinate system) are associated with each other. For example, the user can perform printing by specifying a print point on the processing region R1 from the setting surface R4 while viewing the captured image Pw.

[0257] - Creation of print setting -

[0258] In a subsequent step S12, the setting section 107 sets the processing condition. The setting section 107 sets the processing condition by reading the storage contents in the condition setting storage section 102 or the like, or reading an operation input or the like via the operation terminal 800.

[0259] The processing condition includes a print pattern (mark pattern) Pm indicating a print content or the like, and a print block B indicating the position of the print pattern Pm. The processing condition can be used to adjust the layout, size, rotational posture, or the like of the print block B and the print pattern Pm. In addition, the print block B is used in association with the ranging position I described later.

[0260] The display section 801 can display the print pattern Pm and the print block B so as to overlap the captured image Pw. For example, in Figure 13 , the print pattern Pm including the number "123" and the rectangular print block B surrounding the print pattern are configured on the setting surface R4 on the surface of the workpiece W, and the display section 801 displays the print pattern Pm and the print block B thus configured so as to overlap the captured image Pw.

[0261] Note that the print pattern Pm is an example of a "processing pattern", and the print block B is an example of a "processing block". The names "print pattern" and "print block" are merely for convenience and are not intended to limit their applications.

[0262] Although not shown, a plurality of workpieces Ws can be displayed on the setting surface R4, and as shown in Figure 13 , only one workpiece W can be displayed. In addition, a plurality of print blocks B can be configured on one workpiece W. With regard to the print pattern Pm, a pattern other than a character string, such as a QR code (registered trademark) or the like, can be used.

[0263] Returning to step S12 in Figure 11 , for example, the user manually creates the print block B and configures the print block B on the setting surface R4 in the same step. As described above, since the setting surface R4 and the captured image Pw are associated with each other, the user can configure the print block B while visually recognizing the captured image Pw.

[0264] When one or more print blocks B are configured in this way, the user determines the print pattern Pm of each print block B. For example, the print pattern Pm is determined when the user operates the operation section 802, and the operation section 802 inputs the print pattern Pm to the marking controller 100 based on the operation input at that time.

[0265] The setting section 107 reads the print block B thus configured and the print pattern Pm determined for each print block B to be set as a machining condition. The setting section 107 according to the present embodiment temporarily or continuously stores the coordinates of the print block B on the setting surface R4 and the like (coordinates in the print coordinate system) in the condition setting storage section 102 and the like.

[0266] As described above, since the setting surface R4 is displayed so as to overlap the captured image Pw, the setting section 107 according to the present embodiment sets the print block B so as to overlap the captured image Pw. The setting section 107 is an example of a "machining block setting section" in the present embodiment.

[0267] The machining condition also includes conditions related to the near-infrared laser (hereinafter referred to as "laser conditions"). These laser conditions include at least one of the emission position of the near-infrared laser, the target output (laser power) of the near-infrared laser, the scanning speed of the near-infrared laser with the laser scanning section 4, the repetition frequency (pulse frequency) of the near-infrared laser, whether the laser spot of the near-infrared is variable (spot variability), and the number of times the near-infrared laser traces the print pattern Pm (the number of prints). As shown in the menu D1 displayed in the lower right of Figure 13 As shown in the menu D1 displayed in the lower right of

[0268] - Creation of a search setting -

[0269] Generally, when a production line is operated, misalignment in the X direction and the Y direction (XY direction) occurs among the workpieces W to be sequentially machined. The laser machining apparatus L according to the present embodiment can correct such misalignment using various methods.

[0270] Therefore, in step S13 after step S12, the setting section 107 creates a condition setting (search setting) to correct the misalignment in the XY direction. The laser machining apparatus L according to the present embodiment is configured to use pattern search as a method of correcting the misalignment in the XY direction.

[0271] In order to use pattern search, the setting section 107 sets a pattern region Rp for confirming the position of the workpiece W and a search region Rs defined as a movement range of the pattern region Rp on the captured image Pw as conditions (search conditions) related to pattern search. Note that the pattern region Rp is an example of a "correction region" in the present embodiment.

[0272] Further, the marking controller 100 includes a feature quantity extraction section 105 that extracts image information (feature quantity) of the captured image Pw in the pattern region Rp so as to actually perform the pattern search (refer to Figure 2 ). The feature quantity extraction section 105 according to the present embodiment cuts out the captured image Pw itself in the pattern region Rp as the image information of the captured image Pw. The setting section 107 sets the image cut out by the feature quantity extraction section 105 as the pattern image Pp. The condition setting storage section 102 stores the pattern image Pp set by the setting section 107 (refer to Figure 14D ). The condition setting storage section 102 is an example of the "storage section" in the present embodiment.

[0273] Hereinafter, a specific setting process of the search condition will be described with reference to Figures 14A-14D .

[0274] First, in a first sub-step (step S131) of the step S13, the print block B that is a search target of the pattern search is determined. Specifically, in the example shown in Figure 14A , it is possible to select whether to set all the print blocks B as the search target or to set a specific print block B as the search target by performing a pull-down operation on the dialog box D2.

[0275] Subsequently, in a second sub-step (step S132) of the step S13, the setting section 107 sets the pattern region Rp on the captured image Pw. Specifically, in the example shown in Figure 14B , the pattern region Rp corresponding to each print block B is set by performing a drag operation or the like on the captured image Pw.

[0276] In the example shown in Figure 14B , although the pattern region Rp is set so as to surround the print pattern Pm, the setting is not limited to this setting. It is possible to set the pattern region Rp so as not to surround the print pattern Pm.

[0277] Further, the feature quantity extraction section 105 cuts out the captured image Pp in the pattern region Rp, and sets the cut-out captured image as the image information (pattern image Pp) (refer to Figure 14D ). The pattern image Pp set thereby is input to the setting section 107 or the like.

[0278] Subsequently, in a third sub-step (step S133) of the step S13, the setting section 107 sets the search region Rs on the captured image. Specifically, Figure 14CThe following example is shown: by inputting a value in the input field M1 provided on the dialog box D3, the pattern region Rp is expanded in the amount of the value input in the input field M1 in the horizontal direction and the vertical direction, and the region expanded thereby is set as the search region Rs. The set search region Rs is stored in the condition setting storage section 102 or the like. For example, Figure 14C The search region Rs shown in FIG. 6B is a region obtained by expanding the pattern region Rp vertically and horizontally by about 5 mm, respectively.

[0279] As shown in FIG. 6C, the pattern image Pp as the image information can be confirmed by displaying the dialog box D4 on the display section 801, and the search setting can be set in more detail. Figure 14D For example, the user can operate the drop-down menu for the search setting M2 on the dialog box D4 to select a mode in which the pattern region Rp and the pattern image Pp are reduced and the pattern search is performed at a higher speed (speed priority mode), a mode in which the pattern search is performed at a higher accuracy without reducing the pattern region Rp and the pattern image Pp (accuracy priority mode), or an intermediate mode in which speed is slightly prioritized over the accuracy priority mode while accuracy is slightly prioritized over the speed priority mode (balanced mode), as shown in the example.

[0280] The search condition set in this way is stored in the condition setting storage section 102 or the like as the search setting. When the creation of the search setting is completed, the setting section 107 proceeds from step S13 to step S14.

[0281] - Measurement of the Ranging Setting -

[0282] Generally, when a production line is operated, misalignment in the Z direction occurs in each workpiece W to be sequentially processed. This misalignment causes the focal point position of the near-infrared laser to shift, which is undesirable. Because the laser processing apparatus L according to the present embodiment includes the ranging unit 5, it is possible to detect the misalignment in the Z direction according to the distance to the surface of the workpiece W. As a result, it is possible to correct the misalignment in the Z direction and the shift of the focal point position. Therefore, in step S14 after step S13, a condition setting (ranging setting) for correcting the misalignment in the Z direction is created.

[0283] Specifically, in step S14, a condition (ranging condition) related to the ranging unit 5 is determined. The setting section 107 according to the present embodiment sets at least a ranging position I on the captured image Pw for measuring the distance from the marking head 1 to the surface of the workpiece W as the ranging condition. The ranging position I is basically set to overlap the surface of the workpiece W, and indicates the coordinates at which the ranging light needs to be emitted.

[0284]

[0285] ​When a plurality of printing blocks B are set, the setting unit 107 can set the distance measurement conditions for each printing block B. In this case, the setting unit 107 can set the distance measurement position I within each printing block B (refer to Figure 13 Alternatively, the setting unit 107 may set the distance measurement position I outside each print block B.

[0286] In the following, reference will be made to Figures 15A-15D Describe the specific process of setting distance measurement conditions.

[0287] First, in the first sub-step of step S14 (step S141), the print block B as the distance measurement target (specific measurement target) is determined. Figure 15A In the example shown, by pulling down on dialog box D5, you can select to set all print blocks B as distance measurement targets, set specific print blocks B as distance measurement targets, or select not to set a distance measurement target (No Target). When "No Target" is selected, distance measurement is performed, but the measurement results are not used for position correction in the Z direction.

[0288] exist Figure 15A In the example shown, the tilt of the workpiece W can be detected by performing a pull-down operation rather than measuring the distance (height). To detect the tilt of the workpiece W, distance measurement positions I are set at at least three locations. The tilt of the surface of the workpiece W can be detected by measuring the distances at these three points. In addition to correcting misalignment of the workpiece W in the Z direction, the laser processing apparatus L can also correct the tilt of the workpiece W relative to the XY plane.

[0289] Then, in the second sub-step of step S14 (step S142), the setting unit 107 sets the distance measurement conditions for each print block B. Specifically, Figure 15B As shown, a selection can be made in dialog box D6 between two patterns: a pattern for specifying the identification number (block number) of print block B and a pattern for specifying arbitrary coordinates unrelated to print block B. When the former pattern is selected, setting unit 107 sets the center of the specified print block B as distance measurement position I. On the other hand, when the latter pattern is selected, setting unit 107 specifies the seat surface specified by the user as distance measurement position I.

[0290] Then, in the third sub-step of step S14 (step S143), the setting unit 107 automatically adjusts the distance measurement conditions (refer to Figure 15C Specifically, the setting unit 107 automatically adjusts at least one of the amount of light emitted by the ranging light emitting unit 5A, the light projection time of the ranging light emitting unit 5A, the light receiving gain in the ranging light receiving unit 5B, and the exposure time of the ranging light receiving unit 5B for each print block B as the ranging condition.

[0291] like Figure 15DAs shown, the created ranging condition can be manually changed or the ranging condition can be more finely set by displaying a dialog box D7 on the display section 801.

[0292] For example, the user can change the reference height in the Z direction (i.e., the coordinate of the origin in the Z direction) by inputting a number in the "height coordinate" M3 item on the dialog box D7.

[0293] The ranging condition set in this way is stored in the condition setting storage section 102 or the like as a ranging setting. When the creation of the ranging setting is completed, the setting section 107 proceeds from step S14 to step S15. Assuming that all the settings have been created, the setting section 107 returns from step S15.

[0294] (Execution of printing)

[0295] Figure 16 The specific processing in step S3 of Figure 10 will be described. That is, the processing shown in Figure 16 is sequentially executed for each workpiece W that flows through the operation line.

[0296] First, for the predetermined workpiece W described with reference to step S1 in Figure 10 and steps S11 to S15 in Figure 11 , the marking controller 100 creates in advance the settings such as the print pattern Pm and the print block B (print setting), the settings such as the pattern image Pp (search setting), and the settings such as the ranging position I (ranging setting) before each step shown in Figure 16 (also refer to Figure 17A ).

[0297] When the creation of each setting is completed, the marking controller 100 is in a state in which the control process shown in Figure 16 can be executed. The control process includes a control process for executing XY tracking (pattern search in the XY direction) as a main process (steps S303 to S307) and a control process for executing Z tracking (height measurement in the Z direction) (steps S308 to S312).

[0298] First, in step S301 of Figure 16 , the marker controller 100 operates the laser scanning section 4. The marker controller 100 causes the imaging optical axis Al of the on-axis camera 6 to point to a position that is assumed to carry the workpiece W at the time of operation of the production line. When the wide-angle camera 7 is used instead of the on-axis camera 6, step S301 is not needed.

[0299] In subsequent step S302, if a trigger point is input to the marking controller 100 from the PLC 902 or the like, a new workpiece W' different from the workpiece W for various settings including the pattern region Rp is conveyed.

[0300] Meanwhile, a print block B corresponding to the print pattern Pm is set by a coordinate system defined on the setting surface R4. In addition, the latter workpiece W' can be misaligned in the XY direction with respect to the first workpiece W. As shown in Figure 17B , when misalignment occurs in the XY direction, it can be difficult to form the print pattern Pm at a desired position on the workpiece W'.

[0301] Therefore, the marking controller 100 includes a position correction section 108 to perform pattern search and position correction in the XY direction based on the search result for the new workpiece W'.

[0302] The position correction section 108 generates a new captured image Pw' (refer to Figure 17B ) for at least the new workpiece W' different from the workpiece W used to set the pattern region Rp using the coaxial camera 6 or the wide-angle camera 7.

[0303] The position correction section 108 detects misalignment of the new workpiece W' in the XY direction using the image information (feature quantity) extracted by the feature quantity extraction section 105 and stored in the condition setting storage section 102 on the newly generated captured image Pw'.

[0304] Specifically, the position correction section 108 moves the pattern region Rp within the range of the search region Rs set on the setting surface R4 so as to overlap the newly generated captured image Pw' (refer to Figure 17C ). At substantially the same time as the movement of the pattern region Rp by the position correction section 108, the feature quantity extraction section 105 reextracts the image information of the captured image Pw' within the pattern region Rp after the movement. In particular, the feature quantity extraction section 105 according to the present embodiment cuts out the image in the pattern region Rp after the movement from the captured image Pw' and sets the cut-out image as newly extracted image information (feature quantity).

[0305] The position correction section 108 compares the image information (pattern image Pp) extracted in advance on the first workpiece W with the image information newly extracted on the new workpiece W' to find a region on the newly generated captured image Pw' where the information of the two images highly matches when compared with other regions.

[0306] When there is misalignment in the XY direction between the workpieces W and W', the position correction section 108 takes into account the difference between the coordinates of the pattern region Rp before the movement (coordinates on the setting surface R4) and the coordinates of the region where the information of the two images highly matches when compared with other regions (coordinates on the setting surface R4). When the print block B is moved on the setting surface R4 based on the misalignment detected in this way, the print pattern Pm can be formed at a desired position on the newly conveyed workpiece W'.

[0307] Specifically, in step S303 subsequent to step S302, the marking controller 100 generates a captured image (camera image) Pw' using the coaxial camera 6, and displays the generated captured image Pw' so as to overlap with the setting surface R4.

[0308] Then, in step S304 subsequent to step S303, the marking controller 100 reads the search setting (search condition) for each print block B set as a search target.

[0309] In subsequent step S305, the marking controller 100 performs the pattern search configured as described above. When the pattern search is performed, misalignment in the XY direction between the workpiece W used to create the print setting, the search setting, and the ranging setting, and the workpiece W' newly conveyed during the operation is detected.

[0310] However, at this time, misalignment in the Z direction between the workpieces W and W' has not been resolved. When misalignment occurs in the Z direction (when the height of the workpiece W changes), misalignment in the XY direction further occurs due to the wider angle of view of the coaxial camera 6.

[0311] Therefore, based on the detection result obtained in step S305, misalignment in the XY direction caused by the height of the workpiece W can be maintained only by moving the print block B.

[0312] Therefore, in step S306 subsequent to step S305, the position correction section 108 temporarily corrects misalignment in the XY direction based on the detection result of step S305.

[0313] Specifically, the position correction section 108 shifts the print coordinate system defined on the setting surface R4 in a direction in which misalignment detected by the position correction section 108 is reduced. As a result, the XY coordinates initially set can be converted into temporary XY coordinates (temporary coordinates) at least partially reducing misalignment.

[0314] Since the XY coordinates are converted into the temporary coordinates, the positions of the print blocks B set using the XY coordinates before the conversion are moved to the temporary coordinates with the conversion (refer to Figure 17D ).

[0315] Meanwhile, as described above, each print block B is set to be associated with the ranging position I. Therefore, when the XY coordinates are converted into the temporary coordinates in step S306, the ranging position I also moves with the movement of the print block B. That is, the position correction section 108 corrects the ranging position I on the new workpiece W' corresponding to the ranging position I set by the setting section 107.

[0316] As described above, the position correction section 108 according to the present embodiment is configured to correct the position of the print block B and the ranging position I for the workpiece W and the new workpiece W' based on the detection result of the misalignment in the XY direction. In the following, the corrected ranging position I will be denoted by a reference sign I' (refer to Figure 17D ).

[0317] Then, in step S307 subsequent to step S306, the marker controller 100 determines whether the pattern search has been completed for all the print blocks B that are search targets, and if it is determined YES, proceeds to step S308, and if it is determined NO, returns to step S303.

[0318] In subsequent step S308, the marker controller 100 reads the ranging setting (ranging condition) of each print block B that is a ranging target.

[0319] In subsequent step S309, the control section 101 that is a scan control section controls the laser scan section 4 so that the corrected ranging position I' is irradiated with the ranging light. As a result, the distance from the marking head 1 to the ranging position I' that reflects the conversion to the temporary coordinate system can be measured.

[0320] In subsequent step S310, the ranging section 103 operates the ranging unit 5. At this time, the ranging light exit section 5A measures the distance from the laser processing device L to the surface of the new workpiece W'. Then, the ranging light receiving section 5B receives the ranging light that has been reflected on the surface of the new workpiece W' and returned via the laser scan section 4. As a result, the distance from the marking head 1 to the ranging position I' corrected by the position correction section 108 is measured, and further, the height of the workpiece W' at the ranging position I' is measured.

[0321] In subsequent step S311, the marker controller 100 acquires the Z coordinate of the workpiece W' at the ranging position I' based on the measurement result of the ranging section 103, and detects the misalignment of the workpiece W' in the Z direction. This misalignment can be detected based on the difference between the acquired Z coordinate and the reference height (coordinate of the origin) in the Z direction.

[0322] The marker controller 100 acquires the control parameter of the Z scanner 33 based on the misalignment of the workpiece W' in the Z direction. The control parameter acquired here corresponds to the parameter (correction value of the Z coordinate and the focal position) used when the Z scanner 33 corrects the focal position.

[0323] The parameter thus acquired is used for the control of the Z scanner 33 by the control section 101 before the workpiece W' is subjected to printing. That is, the Z scanner 33 according to the present embodiment is able to adjust the focal position based on the measurement result of the ranging section 103 in the state where the distance measurement position I is corrected by the position correction section 108 before the workpiece W' is irradiated with the near-infrared laser.

[0324] In step S312 subsequent to step S311, the marking controller 100 converts the XY coordinates again based on the misalignment in the Z direction detected in step S311. For this re-conversion, the misalignment in the XY direction detected by the pattern search and the misalignment in the XY direction caused by the height of the workpiece W are considered. As a result, the misalignment of the workpiece W' in the XY direction can be accurately corrected, and the print pattern Pm can be formed at the desired position on the workpiece W'.

[0325] Then, in step S313 subsequent to step S312, the marking controller 100 determines whether the height measurement has been completed for all the ranging positions I, and proceeds to step S314 if the determination is YES, and returns to step S308 if the determination is NO.

[0326] In step S314, the position correction section 108 corrects the emission position of the near-infrared laser in the XYZ directions. In this step S314, both the position correction in the XY direction considering the effect of adding the height of the workpiece W and the position correction in the Z direction based on the height of the workpiece W (i.e., correction of the focal point position) are considered.

[0327] In step S315 subsequent to step S314, the marker controller 100 performs printing on the workpiece W' using the marking head 1 and returns. Because the misalignment in the XYZ directions has been corrected, the control section 101 can perform two-dimensional scanning considering the misalignment detected by the position correction section 108.

[0328] As explained using Figure 15A When the setting to detect the inclination of the workpiece W has been made, the height measurement is performed at at least three ranging positions I. In this case, in the above-described step S314, in addition to the position correction in the XYZ directions, correction for reducing the inclination (inclination correction) is also performed. This inclination correction can be performed using, for example, trapezoidal correction of the captured image Pw'.

[0329] For example, as shown in Figure 18 It is sufficient that the height is measured at the ranging positions II, I2, I3, and I4 in a manner that the ranging positions II, I2, I3, and I4 become four corners and trapezoidal correction is performed based on the measurement results. In this case, the ranging positions II, I2, I3, and I4 are converted to the corrected positions II', I2', I3', and I4', respectively.

[0330] <Relationship between position correction and focal distance>

[0331] Meanwhile, as with the position correction in the XY directions, when a workpiece W having a height is set as a processing target, the processing accuracy can be reduced in the position correction on a two-dimensional plane.

[0332] For example, when the laser scanning unit 4 performs two-dimensional scanning, the focal position of the near-infrared laser light differs between near the center of the processing region R1 set on the workpiece W and near the edge of the processing region R1. Specifically, the focal position becomes further away from the processing region R1 as it moves from the center toward the edge. Therefore, after position correction on the two-dimensional plane, the focal position may deviate. This is problematic in terms of maintaining high processing accuracy.

[0333] For example, Figure 19 As shown, a case where a first workpiece W1 whose focal position Df is optimized by irradiation with a near-infrared laser and a second workpiece W2 which is misaligned with respect to the first workpiece W1 in the XY directions is considered.

[0334] Here, assuming that the irradiation position of the near-infrared laser is moved from S1 to S2 by correcting the misalignment in the XY directions in the second workpiece W2, the focal position Df optimized for the first workpiece W1 is shifted by ΔD from the surface of the second workpiece W2. If the focal position is shifted, it is inconvenient to maintain high processing accuracy.

[0335] In this regard, according to this embodiment, the laser processing apparatus L can detect the misalignment of the workpiece W' in the XY direction using the position correction unit 108, and based on the Figure 16 The detection result shown in step S306 is used to correct the ranging position I. In addition, Figure 16 As shown in step S311 , before irradiating the workpiece W′ with laser light, the laser processing apparatus L corrects the focal position based on the measurement result of the distance measuring unit 103 while the position correcting unit 108 corrects the distance measuring position I.

[0336] In this manner, even if the workpiece W' is misaligned in the configuration of adjusting the focus position in a state in which the misalignment of the workpiece W' has been corrected, high machining accuracy can be maintained.

[0337] like Figure 16 As shown in step S105, the control unit 101 performs two-dimensional scanning in consideration of the misalignment. This is advantageous in terms of maintaining high machining accuracy of the workpiece W'.

[0338] like Figure 17D As shown, by correcting the position of the print block B using the search results of the pattern search, the ranging position I with respect to the print block B can be corrected. This is advantageous in terms of maintaining high machining accuracy of the workpiece W'.

[0339] like Figure 17A As shown in FIG. 1 and FIG. 2 , by setting the distance measuring position I in the print block B, the distance measuring position I is more appropriately set, which is advantageous in terms of maintaining high processing accuracy of the workpiece W′.

[0340]

[0341] In the above-described embodiment, the feature amount extraction section 105 is configured to directly use the captured image Pw in the pattern region Rp as the image information of the captured image Pw, but the present disclosure is not limited to this configuration. The feature amount extraction section 105 can also use edge information of the captured image Pw in the pattern region Rp as the image information of the captured image Pw.

[0342] In addition, in the above-described embodiment, the ranging position I is set for each print block B, but the method of setting the ranging position I can be appropriately changed. For example, the ranging position I can be set as a relative coordinate with respect to the print block B, or the ranging position I can be set as a relative coordinate with respect to the pattern region Rp or the search region Rs. Alternatively, the ranging position I can be set as an absolute coordinate that is not related to any of the print block B, the pattern region Rp, and the search region Rs.​

Claims

1. A laser processing apparatus comprising: an excitation light generating section that generates excitation light; a laser light output section that generates laser light based on the excitation light generated by the excitation light generating section and outputs the laser light; a focal point adjusting section that adjusts a focal point position of the laser light output from the laser light output section; a laser light scanning section that irradiates a workpiece with the laser light whose focal point position is adjusted by the focal point adjusting section and performs two-dimensional scanning within a processing region set on a surface of the workpiece; an imaging section that has an imaging optical axis and images the workpiece to generate an imaging image including at least a part of the processing region without the laser light scanning section on the imaging optical axis; a setting section that sets, on the imaging image generated by the imaging section, a correction region for identifying a position of the workpiece and a ranging position for measuring a distance to the surface of the workpiece, respectively; a storage section that stores image information in the correction region set by the setting section; a position correction section that detects misalignment of a new workpiece on a newly generated imaging image by the imaging section using the image information stored in the storage section with respect to the new workpiece different from the workpiece for which the correction region is set, and corrects a ranging position on the new workpiece corresponding to the ranging position set by the setting section based on a detection result of the misalignment; a ranging light output section that outputs ranging light for measuring a distance from the laser processing apparatus to the surface of the new workpiece; a scanning control section that controls the laser light scanning section to irradiate the ranging position corrected by the position correction section with the ranging light output by the ranging light output section; a ranging light receiving section that receives the ranging light reflected on the surface of the new workpiece and returned via the laser light scanning section; and a ranging section that measures a distance from the laser processing apparatus to the ranging position corrected by the position correction section based on a light-receiving position of the ranging light in the ranging light receiving section, wherein the focal point adjusting section adjusts the focal point position based on a measurement result of the ranging section before the new workpiece is irradiated with the laser light.

2. The laser processing apparatus according to claim 1, wherein the scanning control section controls the laser light scanning section to perform two-dimensional scanning with consideration of the misalignment detected by the position correction section. the laser processing apparatus further comprises:

3. The laser processing apparatus according to claim 1, characterized by, a processing block setting section that sets a processing block indicating a position of a processing pattern formed within the processing region and associated with the ranging position so as to overlap the imaging image, wherein the position correction section corrects a position of the processing block based on the detection result of the misalignment.

4. The laser processing apparatus according to claim 3, wherein the setting section sets the ranging position within the processing block.

5. The laser processing apparatus according to claim 1, wherein the imaging section includes at least: ​ a second imaging section that has an imaging optical axis independent of a laser path from the laser output section to the laser scanning section, and that generates the captured image without the laser scanning section, and the position correction section corrects the ranging position based on a captured image newly generated by the second imaging section.

6. The laser processing apparatus according to claim 5, characterized by The laser processing apparatus further includes: a controller in which the excitation light generation section is provided; a head in which the laser output section, the focal point adjustment section, the laser scanning section, and the second imaging section are provided; and an optical fiber cable through which the controller and the head are optically coupled.

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