Laser processing device and laser head anomaly detection method

Abstract

This laser processing device comprises at least a laser oscillator that generates laser light, a laser head that emits the laser light toward a workpiece, and a control unit. The laser head accommodates at least a first lens for condensing the laser light toward the workpiece, a first glass that transmits the laser light, and one or more first sensors that are disposed between the first lens and the first glass in the direction in which the laser light is emitted toward the workpiece. The control unit detects the presence or absence of an anomaly in at least one of the first lens and the first glass on the basis of detection output from the first sensor.

Description

Laser processing device and laser head abnormality detection method

[0001] The present disclosure relates to a laser processing apparatus and a laser head abnormality detection method.

[0002] Patent Document 1 discloses a method for checking the condition of a protective glass disposed between a workpiece and a laser optic in a laser machining system for contamination. The protective glass is disposed so that a machining laser beam passes through it. A heat detector senses the temperature of the protective glass or its holder and is disposed in mechanical contact with the holder to have good thermal contact.

[0003] Patent Document 2 discloses a device for detecting contamination on a protective glass in a laser welding machine, which protects the laser head from contamination by flying deposits such as spatter or fumes from the workpiece. This contamination detection device includes a bandpass filter that transmits light of a specific wavelength from scattered light emitted from the side surface of the protective glass, and a photosensor that detects the transmitted light that has passed through the bandpass filter.

[0004] Japanese Patent Publication No. 2002-515341 Japanese Patent Publication No. 2019-195814

[0005] The present disclosure has been devised in consideration of the conventional circumstances, and aims to provide a laser processing device and a laser head abnormality detection method that can easily detect whether or not there is dirt on optical elements, etc. inside a laser head that irradiates a laser beam toward a workpiece.

[0006] The present disclosure provides a laser processing device including at least a laser oscillator that generates laser light, a laser head that irradiates the laser light toward a workpiece, and a control unit, wherein the laser head houses at least a first lens that focuses the laser light toward the workpiece, a first glass that transmits the laser light, and one or more first sensors that are arranged between the first lens and the first glass in the direction in which the laser light is irradiated toward the workpiece, and the control unit detects the presence or absence of an abnormality in at least one of the first lens and the first glass based on the detection output of the first sensor.

[0007] The present disclosure also provides a laser head abnormality detection method executed by a laser processing device including at least a laser oscillator that generates laser light, a laser head that irradiates the laser light toward a workpiece, and a control unit, wherein the laser head houses at least a first lens that focuses the laser light toward the workpiece, a first glass that transmits the laser light, and one or more first sensors that are arranged between the first lens and the first glass in the direction in which the laser light is irradiated toward the workpiece, and the laser head abnormality detection method includes the steps of: acquiring a detection output of the first sensor by the control unit; and detecting, by the control unit, the presence or absence of an abnormality in at least one of the first lens and the first glass based on the detection output of the first sensor.

[0008] According to the present disclosure, it is possible to easily detect whether or not there is an abnormality in an optical element or the like inside a laser head that irradiates a laser beam toward a workpiece.

[0009] Schematic diagram showing an example of the configuration of a laser processing device according to this embodiment. FIG. 1 shows a first example of a laser beam profile. FIG. 2 shows a second example of a laser beam profile. Schematic diagram showing a see-through view of the inside side of the laser head. Schematic diagram showing an example of a state in which a protective glass holder is inserted into an upper head block. Schematic diagram showing an example of a state in which a protective glass holder is inserted into a lower head block. FIG. 2 shows an example of a threshold value table stored in a memory. Flowchart showing the chronological order of the operation procedure for detecting the presence or absence of an abnormality inside the laser head by the head processing unit of the laser processing device.

[0010] (Background to the present disclosure) During laser processing, the surface of a protective glass disposed near the output end of an optical element (e.g., a lens) inside a laser head is gradually contaminated by fumes, spatter, and other flying particles generated by the workpiece, which is the object to be processed, due to irradiation with laser light. The protective glass is not limited to being disposed near the output end of the optical element; for example, it may also be disposed above the laser head to prevent contamination when inserting or removing an optical fiber. Accumulation of contamination on the protective glass can result in a decrease in laser output, a focus shift, and other problems. This adversely affects the quality of the workpiece processed by laser processing, and in the worst case scenario, can even result in burnout of the optical element inside the laser head. To avoid such burnout, the operator must clean or replace the protective glass.

[0011] In the configuration of Patent Document 1, by the time an abnormality due to a temperature rise is detected, contamination such as damage to the optical elements may have already progressed, and secondary contamination inside the laser head may have occurred. In the configuration of Patent Document 2, while it is possible to detect contamination on the protective glass alone, there is a problem in that it is difficult to detect whether or not there is an abnormality (for example, deterioration of characteristics) in the optical elements such as lenses arranged inside the laser head.

[0012] Abnormalities in the protective glass alone can include a decrease in laser output and damage to the protective glass due to contamination from scattered deposits such as fumes or spatter. However, because expensive protective glasses are often used to obtain a certain level of transmittance even when using high-power lasers, there is a demand for them to be used for as long as possible. Furthermore, for long-term use, it is necessary to detect deterioration of the anti-reflection (AR) coating applied to the protective glass and optical elements, and to detect contamination of optical elements other than the protective glass inside the laser head. In other words, since factors other than the protective glass can cause processing defects in laser processing, early identification of the cause of the deterioration in laser processing quality is required to minimize downtime from the occurrence of an abnormality to the resumption of processing.

[0013] Therefore, in the following embodiments, an example of a laser processing apparatus and a laser head abnormality detection method will be described, which can easily detect whether or not there is an abnormality in an optical element or the like inside a laser head that irradiates a laser beam toward a workpiece.

[0014] Hereinafter, with reference to the drawings as appropriate, detailed descriptions of embodiments specifically disclosing a laser processing apparatus and a laser head abnormality detection method according to the present disclosure will be provided. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters or redundant descriptions of substantially identical configurations may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art. Note that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure and are not intended to limit the subject matter recited in the claims.

[0015] 1. Definition of Terms In the following description, unless otherwise explicitly stated, the term "laser processing" has the broadest possible meaning, and "processing" may be replaced with "welding." The terms "processing" and "welding" include processes such as soldering, melting, joining, annealing, softening, tackifying, resurfacing, peening, heat treatment, fusing, sealing, stacking, cutting, and ablation.

[0016] In the following description, unless explicitly stated otherwise, the terms "blue laser beam" and "blue laser" have the broadest possible meaning and refer to a laser beam or light having a blue wavelength band (e.g., a wavelength of about 400 nm to about 500 nm). Furthermore, unless explicitly stated otherwise, the terms "infrared," "infrared light," and "NIR" have the broadest possible meaning and refer to a laser beam or light having a near-infrared wavelength band (e.g., a wavelength of 900 nm to 1000 nm).

[0017] 2. Configuration of Laser Processing Apparatus First, the configuration of a laser processing apparatus 100 according to this embodiment will be described with reference to FIG.

[0018] FIG. 1 is a schematic diagram showing an example of the configuration of a laser processing apparatus 100 according to this embodiment. In the following description, the direction of irradiation of laser light LB from the laser head 60 toward the workpiece 200 is referred to as the Z direction. The direction intersecting the X direction on the surface of the workpiece 200 shown in FIG. 1 is sometimes referred to as the Y direction. The directions intersecting both the X direction and the Y direction are sometimes referred to as the Z direction. In addition, in the Z direction, the side on which the laser head 60 is disposed relative to the workpiece 200 is sometimes referred to as the upper side or upper side, and the side on which the workpiece 200 is disposed relative to the laser head 60 is sometimes referred to as the lower side or lower side.

[0019] 1, the laser processing apparatus 100 includes a laser oscillator 10, an optical unit 20, an optical fiber 30, an XY stage 50, a laser head 60, and a controller 70. The controller 70 includes a laser control unit 71, a stage control unit 72, a head processing unit 73, and a memory 74. A display DP1 is connected to the controller 70 and functions as a monitor for displaying a screen of the processing results of each unit of the controller 70.

[0020] The laser oscillator 10 generates laser light LB and emits it toward the optical unit 20 based on a command from the laser control unit 71 of the controller 70. In this embodiment, the wavelength of the laser light LB may be, for example, approximately 900 nm to 1000 nm, which is the wavelength band of an infrared laser, and the output may be approximately 1 kW to 5 kW. However, these are not particularly limited and may be other values. For example, if the laser light LB is a blue laser, its wavelength band may be approximately 400 nm to 500 nm, and the output may be approximately 0.4 kW. In other words, based on a command from the laser control unit 71, the laser oscillator 10 can generate laser light of a wavelength band and output corresponding to the command. The laser oscillator 10 may also be equipped with a separate laser light source (not shown) that emits a guide laser light. The wavelength of this guide laser light is, for example, visible light of approximately 650 nm, and the output is approximately several mW to several tens of mW, which is significantly lower than the output of the laser light LB described above. The optical axis of the guide laser light is substantially aligned with the optical axis of the laser light LB.

[0021] Although not shown, the laser oscillator 10 may include multiple laser modules and a beam combiner, which may be used to generate the blue laser beam LB. The laser oscillator 10 uses the beam combiner to combine laser beams of different wavelengths (e.g., wavelengths of 400 nm, 420 nm, 440 nm, 480 nm, etc., within a range of approximately 400 nm to 500 nm) emitted from the multiple laser modules into a single blue laser beam. The laser oscillator 10 may also be referred to as a Direct Diode Laser (DDL) oscillator. The laser module itself is composed of multiple laser diodes, e.g., a semiconductor laser array.

[0022] In this specification, "substantially the same" or "substantially orthogonal" includes the processing tolerances and assembly tolerances of each component that constitutes the laser processing apparatus 100, and refers to the fact that the objects being compared are the same or orthogonal, but does not mean that the objects being compared are the same or orthogonal in the strict sense.

[0023] 2A and 2B, the profile of the laser light generated from the laser oscillator 10 will be described. Fig. 2A is a diagram showing a first example of the profile of the laser beam. Fig. 2B is a diagram showing a second example of the profile of the laser beam.

[0024] In the profile LBP1 of the laser beam LB1 shown at the bottom of the page in Fig. 2A, the horizontal axis represents the distance from the center of the optical axis of the laser beam LB1, and the vertical axis represents the intensity of the laser beam LB1. The profile LBP1 in Fig. 2A has a characteristic in which the intensity is highest at the center of the laser beam LB1 and gradually decreases with increasing distance from the center (in other words, an oscillation mode), which is a so-called Gaussian distribution. Hereinafter, the oscillation mode of this profile LBP1 may be referred to as Gaussian.

[0025] In the profile LBP2 of laser beam LB2 shown at the bottom of Figure 2B, the horizontal axis represents the distance from the center of the optical axis of laser beam LB2, and the vertical axis represents the intensity of laser beam LB2. Profile LBP2 in Figure 2B has the characteristic that the intensity of laser beam LB1 is higher at a position slightly away from the center than at the center, and the intensity gradually decreases with increasing distance from that position, resulting in a so-called doughnut-shaped or ring-shaped distribution. Hereinafter, the oscillation mode of profile LBP2 may be referred to as a ring.

[0026] As described above, in this embodiment, the laser beam LB generated from the laser oscillator 10 has at least one of the different profiles LBP1 and LBP2 shown in FIGS. 2A and 2B . Therefore, regardless of which profile the laser beam is irradiated onto the workpiece 200, various thresholds (see FIG. 6 ) are preset according to the profile so that the presence or absence of an abnormality (see below) in the laser head 60 can be appropriately determined. The abnormality here refers to, for example, at least one of dirt, scratches, and deterioration in the optical elements (see below) or protective glass disposed within the laser head 60, and this also applies to the following description. Note that, although two types of laser beams LB1 and LB2 are shown as examples of the profile of the laser beam LB generated from the laser oscillator 10, the profile of the laser beam LB is not limited to these.

[0027] The optical unit 20 has a housing 21. The optical unit 20 houses a condenser lens 22 inside the housing 21. The condenser lens 22 condenses the laser light LB that has entered the housing 21, and makes the laser light LB enter the optical fiber 30. Note that the optical unit 20 may further be provided with a condensing position adjustment mechanism (not shown) in order to align the condensing position of the laser light LB with the incident end face of the optical fiber 30.

[0028] One end of the optical fiber 30 is connected to the optical unit 20, and the other end is connected to the upper end of the laser head 60. The optical fiber 30 transmits the laser light LB or the guide laser light incident from the optical unit 20 to the laser head 60. Although not shown, the optical fiber 30 has one or more cores that serve as a waveguide for the laser light LB or the guide laser light.

[0029] The XY stage 50 includes a stage on which the workpiece 200 is placed, and displaces the workpiece 200 in both the X and Y directions by a movement amount corresponding to the command based on a command from the controller 70 (specifically, the stage control unit 72). The XY stage 50 may employ any known configuration as long as it is capable of driving the placed workpiece 200 in two dimensions. Furthermore, the XY stage 50 may hold the laser head 60 in a fixed manner during any of the operation programs described below, or may move the laser head 60 up and down along the Z direction by a predetermined amount corresponding to the command based on a command from the controller 70 (specifically, the stage control unit 72). A cable (not shown) provided between the controller 70 and the XY stage 50 houses a cooling hose (not shown) for the laser head 60 and I / O lines (not shown) for a thermal switch and the like. Furthermore, the movement of the workpiece 200 in the XY directions and the movement of the laser head 60 in the Z direction may be performed via a manipulator (not shown) that can be controlled by the controller 70 instead of the XY stage 50 .

[0030] The laser head 60 is attached to a laser head 60 holder (not shown) provided on the XY stage 50. The laser head 60 irradiates the workpiece 200 with the laser beam LB or a guide laser beam transmitted from the optical fiber 30 to the laser head 60. As a result, the laser beam LB is irradiated from the laser head 60, and the workpiece 200 is laser-machined by the laser beam LB. The laser head 60 also has an internal optical system (e.g., a collimation lens, a condenser lens) and a photosensor (see FIG. 3 ), which converts the laser beam LB into parallel light and then condenses it on the surface of the workpiece 200. An example of the internal structure of the laser head 60 will be described later with reference to FIG. 3 . The photosensor and controller 70 are connected so that data detected by the photosensor can be input to the controller 70.

[0031] The controller 70 controls the operation (e.g., generation and stopping) of the laser beam LB from the laser oscillator 10 or the guide laser, and controls the operation of the XY stage 50 (e.g., movement of the workpiece 200 in the X and Y directions, and movement of the laser head 60 in the Z direction). The controller 70 also determines whether or not there is an abnormality in the laser head 60 (e.g., dirt, scratches, or deterioration of the optical elements or protective glass in the laser head 60) based on data of values ​​detected by a photosensor (see FIG. 3 ) disposed in the laser head 60. As described above, the controller 70 includes a laser control unit 71, a stage control unit 72, a head processing unit 73, and a memory 74.

[0032] The laser control unit 71 is electrically connected to the laser oscillator 10 and controls the operation of the laser oscillator 10. The laser control unit 71 also controls the operation of a laser drive power supply (not shown) connected to the laser oscillator 10. Specifically, based on the control (command) of the laser control unit 71, the laser oscillator 10 controls the output of the laser light LB or the guide laser light, the oscillation time, and the timing of starting and stopping the oscillation of the laser light LB or the guide laser light.

[0033] The stage control unit 72 generates a command to move (scan) the mounting base of the XY stage 50, on which the workpiece 200 to be laser processed is placed, in the X and Y directions (i.e., two-dimensionally), and sends the command to the XY stage 50. As a result, based on the command from the stage control unit 72, the XY stage 50 moves the mounting base in the X and Y directions by the movement amount specified in the command, thereby enabling the laser light LB emitted from the laser head 60 to be irradiated onto the workpiece 200.

[0034] The controller 70 also includes a head processing unit 73 for detecting whether or not there are any abnormalities in the optical elements and protective glass (see Figure 3) inside the laser head 60 based on data of values ​​detected by a photosensor (see Figure 3) inside the laser head 60.

[0035] The head processing unit 73 detects whether or not there is an abnormality in the optical elements and protective glass (see FIG. 3) inside the laser head 60, based on the detection values ​​of one or more photosensors (see FIG. 3) arranged inside the laser head 60 and a threshold value table (see FIG. 6) stored (registered) in the memory 74. The head processing unit 73 generates a screen showing the detection results (for example, a message indicating that there is no dirt, a message urging cleaning or replacement because dirt has accumulated, or an error output indicating that use should be prohibited because the dirt is so severe) and displays it on the display DP1, or stops the operation of the laser oscillator 10 based on the detection results.

[0036] The memory 74 includes a random access memory (RAM) and a read-only memory (ROM). The RAM temporarily stores data or information acquired or generated by the laser control unit 71, the stage control unit 72, and the head processing unit 73. The ROM stores programs and data used for various processes executed by the laser control unit 71, the stage control unit 72, and the head processing unit 73. The memory 71b stores (registers) data of a threshold value table (see FIG. 6) that is referenced when the head processing unit 73 detects abnormalities in the optical elements and protective glass (see FIG. 3) inside the laser head 60. This data may be appropriately modified and stored (registered) as needed, at times other than when the laser processing apparatus 100 is in operation.

[0037] The threshold value table TBL1 will now be described with reference to Fig. 6. Fig. 6 is a diagram showing an example of the threshold value table TBL1 stored in the memory 74.

[0038] The threshold table TBL1 has a plurality of one-row records each including an operation program, an output command value, an oscillation mode, threshold 1, threshold 2, threshold 3, and threshold 4. Although not shown in FIG. 6 , threshold 5 (not shown) may also be included in the same record. The operation programs include an output confirmation program for determining whether various abnormalities or their precursors are detected within the laser head 60 using the laser beam LB or a guide laser, and a construction program for performing actual processing (machining) using the laser beam LB. The operation programs can be used in a Teach mode, in which the laser beam LB is not emitted, or an Auto mode, in which the laser beam LB is emitted. The Teach mode, in which the guide laser beam is used, or the Auto mode, in which the actual processing laser beam LB is used, may be used to execute the output confirmation program.

[0039] For example, to determine the various threshold values ​​in the threshold table TBL1, a power meter (not shown) that absorbs laser light LB is placed on the mounting table of the XY stage 50, where the workpiece 200 is placed, instead of the workpiece 200, and the appropriate threshold value for the Auto mode is determined in advance by the output of the power meter that absorbs this laser light, using the laser light LB of the wavelength, output, and oscillation mode used during the Auto mode process (actual processing). When using the Auto mode construction program, unlike the Teach mode, the workpiece 200, which is the object to be processed, is placed on the mounting table of the XY stage 50 instead of a power meter, and actual processing (welding) is performed.

[0040] In order to determine the various thresholds in the threshold table TBL1, a low-output power meter (not shown) that absorbs the guide laser light may be placed on the mounting table of the XY stage 50, where the workpiece 200 is placed, and an appropriate threshold for the Teach mode may be determined in advance based on the output of the low-output power meter that absorbs this laser light, using the guide laser light of the wavelength, output, and oscillation mode used in the Teach mode. This makes it possible to easily predict and determine various abnormalities or their precursors inside the laser head 60 by using the low-output guide laser light without using the actual high-output laser light used in the Auto mode.

[0041] Threshold 1 is the detection value of photosensors PD1 and PD2 when an abnormality inside the laser head 60 is specifically detected due to burnout or fire of the protective glass SG1, SG2 or optical elements (e.g., collimation lens CLL1, focusing lens FCL1; the same applies below in the description of FIG. 6 ) inside the laser head 60. Threshold 1 is a value greater than threshold 2. For example, if the protective glass or optical elements are dirty, scratched, or deteriorated, the amount of laser light absorbed by the abnormal area increases, resulting in a high temperature. This can cause deterioration of the coating film, such as an AR coating, applied to the protective glass or optical elements. Further, the absorption of laser light progresses, causing the protective glass or optical elements to heat up and burn. This heat generation can cause traces of residual oil or volatile components from resin components to be generated, degrading the characteristics of the protective glass or optical elements inside the laser head. Specific examples of deterioration include a decrease in transmittance due to an oil film, an increase in scattered light due to the adhesion of impurities, and the occurrence of a thermal lens due to increased laser light absorption. Threshold 1 is a threshold set to immediately notify an operator or the like that an event has occurred that makes it unsuitable to continue using the optical element due to the adverse effects of such burnout. If a detection value equal to or greater than this threshold 1 is obtained, use of the device in Auto mode will be stopped.

[0042] Threshold 2 is the detection value of photosensors PD1 and PD2 when there is an increase in precursory phenomena of an abnormality that may possibly affect the protective glasses SG1 and SG2 or the optical elements around them inside the laser head 60, but which does not necessarily lead to an abnormality such as burning or ignition of the protective glasses SG1 and SG2 or the optical elements (threshold 1 > threshold 2). Thresholds 1 and 2 are examples of upper thresholds. If a detection value equal to or greater than threshold 2 is obtained, use of the device in Auto mode is stopped, just as if a detection value equal to or greater than threshold 1 is obtained.

[0043] Threshold 3 is the detection value of the photosensors PD1 and PD2 when it is time to replace the protective glasses SG1 and SG2 due to, for example, the start of deterioration of the AR coating film applied to the protective glasses SG1 and SG2 (threshold 2>threshold 3). Note that if a detection value is obtained that is equal to or greater than threshold 3 but less than threshold 2, it is assumed that there is a possibility that an abnormality may have occurred inside the laser head 60, and therefore use of the device in Auto mode is not stopped.

[0044] Threshold 4 is the detection value of the photosensors PD1 and PD2 when it is predicted that there is an abnormality (for example, an abnormal operation of the equipment due to a drop in output, etc.) in the equipment (for example, the laser oscillator 10, the optical unit 20, the optical fiber 30) located upstream of the laser head 60. Threshold 4 is an example of a lower limit threshold.

[0045] 6 shows a mixture of various thresholds for the output confirmation program and various thresholds for the construction program, but the threshold table for the output confirmation program and the threshold table for the construction program may be provided as separate tables. In this case, the head processing unit 73 may read out the threshold table for the output confirmation program or the threshold table for the construction program, for example, depending on whether or not light is reflected from the workpiece.

[0046] For example, in the record "output confirmation program, 1.0 kW, Gaussian, Thg111 (threshold 1), Thg211 (threshold 2), Thg311 (threshold 3), Thg411 (threshold 4)," the output confirmation program is executed, and the laser beam output command value required for execution of the program is 1.0 kW, which is the high output for Auto mode. If the detection values ​​of the photosensors PD1 and PD2 exceed Thg111, it is determined that dirt, scratches, or deterioration due to burnout or fire has been detected on the protective glasses SG1 and SG2 and optical elements inside the laser head 60, and operation is immediately stopped. Similarly, if the detection values ​​of the photosensors PD1 and PD2 exceed Thg211 but do not reach Thg111, the head processing unit 73 determines that a precursor phenomenon of an abnormality (e.g., dirt, scratches, or deterioration) has been detected on the protective glasses SG1 and SG2 and optical elements inside the laser head 60 that does not reach the level of dirt, scratches, or deterioration due to burnout or fire. Similarly, if the detection values ​​of the photosensors PD1 and PD2 are less than Thg411, the head processing unit 73 determines that there is a high possibility that an abnormality (e.g., an abnormal operation of the equipment) has occurred in the equipment (e.g., the laser oscillator 10, the optical unit 20, the optical fiber 30) arranged upstream of the laser head 60. In this case, it is not desirable to continue using the upstream equipment (e.g., the laser oscillator 10, the optical unit 20, the optical fiber 30) in terms of the continued operation of the laser processing apparatus 100, so it is preferable that the equipment be replaced early after a message to the effect that continued use is difficult is displayed on the display DP1.

[0047] Furthermore, regardless of the oscillation mode, if the detection values ​​of the photosensors PD1 and PD2 are abnormal (i.e., exceeding threshold value 4) in either the output confirmation program or the construction program, it is assumed that there is an abnormality in the equipment (e.g., the laser oscillator 10, the optical unit 20, the optical fiber 30) of the laser processing apparatus 100. The head processing unit 73 may determine whether there is an abnormality (such as dirt) in the equipment or optical elements of the laser processing apparatus 100 by executing the processing of Fig. 7 described below.

[0048] On the other hand, if the detection values ​​of the photosensors PD1 and PD2 when the operating program is the processing program are substantially equal to the threshold value (e.g., threshold value 5) during normal processing (i.e., when laser processing is performed normally), it is assumed that there is no abnormality in the equipment (e.g., laser oscillator 10, optical unit 20, optical fiber 30) of the laser processing apparatus 100. The processor 71a may determine whether or not there is an abnormality (such as dirt) in the equipment or optical elements of the laser processing apparatus 100 by executing the processing of Fig. 7 described below.

[0049] On the other hand, if the detection values ​​of the photosensors PD1 and PD2 are abnormal (i.e., exceed threshold value 3) when the operating program is the construction program, deterioration of the AR coding of each of the protective glasses SG1 and SG2 is inferred. The head processing unit 73 may determine whether or not there is an abnormality (such as dirt) in the equipment or optical elements of the laser processing apparatus 100 by executing the processing in FIG. 7 described below.

[0050] For example, in the record "output confirmation program, guide light ON command, ring, Thr112, Thr212, Thr312, Thr412," the output confirmation program is executed, and the output command value of the guide laser light required for execution of the program is a default value (e.g., 0.005 kW). If the detection values ​​of the photosensors PD1 and PD2 exceed Thr112, it is simply determined that dirt, scratches, or deterioration due to burnout or fire has been detected in the protective glasses SG1 and SG2 and optical elements inside the laser head 60, without the need to use the laser light LB for actual processing (construction). Similarly, if the detection values ​​of the photosensors PD1 and PD2 exceed Thr212 but do not reach Thr122, the head processing unit 73 determines that a precursor phenomenon of an abnormality (e.g., dirt, scratches, or deterioration) has been detected in the protective glasses SG1 and SG2 and optical elements inside the laser head 60, but not to the extent of dirt, scratches, or deterioration due to burnout or fire. Similarly, if the detection values ​​of the photosensors PD1 and PD2 are each less than Thr412, the head processing unit 73 determines that there is a high possibility that an abnormality (e.g., an abnormal operation of the equipment) has occurred in the equipment (e.g., the laser oscillator 10, the optical unit 20, the optical fiber 30) arranged upstream of the laser head 60. In this case, it is not desirable to continue using the upstream equipment (e.g., the laser oscillator 10, the optical unit 20, the optical fiber 30) in terms of the continued operation of the laser processing apparatus 100, so that a message or the like indicating that continued use is difficult is displayed on the display DP1, and it is therefore preferable that the equipment be replaced as soon as possible.

[0051] Furthermore, if the head processing unit 73 determines that the detection value of the photosensor PD1 is normal (for example, a value between threshold 3 and threshold 4) and the detection value of the photosensor PD2 is at the lower limit of abnormality (for example, a value below threshold 4), it determines that an abnormality has occurred in the protective glass SG1, SG2 or the optical element within the laser head 60.

[0052] Furthermore, the head processing unit 73 may combine the detection values ​​of the photosensors PD1 and PD2 with different threshold values ​​corresponding to the operating program, output command value, and oscillation mode to determine whether or not there is an abnormality in the protective glasses SG1 and SG2 and optical elements inside the laser head 60. Although this is merely a limited example, the head processing unit 73 can make the following determination based on the detection values ​​of the photosensors PD1 and PD2.

[0053] (Detection example 1) The detection values ​​of the photosensors PD1 and PD2 are both normal (for example, between threshold value 3 and threshold value 4). In this case, the head processing unit 73 determines that there is no abnormality in any of the protective glasses SG1 and SG2 or the optical elements inside the laser head 60, and outputs this information to the display DP1, etc.

[0054] (Detection example 2) When the detection value of photosensor PD1 is normal (for example, between threshold value 3 and threshold value 4), but the detection value of photosensor PD2 is abnormal (for example, above threshold value 1), the head processing unit 73 determines that there is no abnormality in the protective glass SG1 and optical element (collimation lens CLL1) in the upper head block 61 of the laser head 60, but that there is an abnormality in at least one of the protective glass SG2 and optical element (focusing lens FCL1) in the lower head block 62, and outputs this information to the display DP1, etc.

[0055] (Detection example 3) When the detection value of photosensor PD2 is normal (for example, between threshold value 3 and threshold value 4), but the detection value of photosensor PD1 is abnormal (for example, above threshold value 1), the head processing unit 73 determines that there is no abnormality in the protective glass SG2 and optical element (focusing lens FCL1) in the lower head block 62 of the laser head 60, but that there is an abnormality in at least one of the protective glass SG1 and optical element (collimation lens CLL1) in the upper head block 61, and outputs this information to the display DP1, etc.

[0056] (Detection Example 4) The detection values ​​of the photosensors PD1 and PD2 are both abnormal (for example, less than threshold value 4). In this case, the head processing unit 73 determines that there is no abnormality inside the laser head 60, but that there is an abnormality (for example, a decrease in output) in at least one of the laser oscillator 10, optical unit 20, and optical fiber 30 located upstream, and outputs this information to the display DP1, etc.

[0057] The display DP1 is configured using, for example, a Liquid Crystal Display (LCD) or an organic electroluminescence (EL) display, and is connected to the controller 70 so as to allow input and output of data signals. The display DP1 displays a screen showing the processing results of each part of the controller 70 (for example, a message indicating that there is no dirt, a message urging cleaning or replacement due to accumulated dirt, or an error output indicating that use should be prohibited due to severe dirt).

[0058] 3. Structure of the Laser Head Next, the structure of the laser head 60 of the laser processing apparatus 100 according to this embodiment will be described with reference to FIGS.

[0059] Fig. 3 is a schematic view showing a see-through view of the inner side surface of the laser head 60. Fig. 4 is a schematic view showing an example of a state in which the protective glass holder SH1 is inserted into the upper head block 61. Fig. 5 is a schematic view showing an example of a state in which the protective glass holder SH2 is inserted into the lower head block 62.

[0060] In this embodiment, the laser head 60 has a structure in which an upper head block 61 and a lower head block 62 are connected and detachable from each other. That is, in the laser head 60, the upper head block 61 can be detached from the lower head block 62, and the lower head block 62 can also be detached from the upper head block 61.

[0061] The upper head block 61 accommodates, from top to bottom along the Z direction, a protective glass SG1, a photosensor PD1, and a collimation lens CLL1.

[0062] The collimation lens CLL1 has the function of collimating (that is, parallelizing) the laser light LB that has been guided from the optical fiber 30 into the laser head 60 and passed through the protective glass SG1.

[0063] The protective glass SG1 is held at a predetermined position in a protective glass holder SH1 that has a rectangular shape in the XY plane and a constant thickness (Z direction) (see FIG. 4). The protective glass holder SH1 is formed so that it can be inserted into and removed from the upper head block 61 of the laser head 60 in the X direction. In other words, the protective glass SG1 can be easily replaced by placing it in the protective glass holder SH1 and inserting it into the upper head block 61.

[0064] In this embodiment, for example, three photosensors PD1 are provided, and they are arranged to surround the protective glass SG1 in the XY plane directions perpendicular to the Z direction (see FIG. 4 ). Specifically, three photosensors PD1a, PD1b, and PD1c are arranged. Each of the photosensors PD1a, PD1b, and PD1c receives scattered light of the laser beam LB that has passed through the protective glass SG1 in the upper head block 61. The photosensors PD1a, PD1b, and PD1c may have sensitivity to light in the same wavelength band or different wavelength bands. For example, the photosensor PD1a may have broadband sensitivity to the output wavelength of the laser beam LB (e.g., 445 nm), the photosensor PD1b may have sensitivity only to wavelengths near the output wavelength of the laser beam LB (e.g., 445 nm), and the photosensor PD1c may have higher sensitivity to the infrared region (e.g., 900 nm) than the output wavelength of the laser beam LB (e.g., 445 nm). Therefore, for example, if the detection value of photosensor PD1c increases, it is assumed that the reflected light state of the laser light has changed based on the processing state of the workpiece 200. On the other hand, if the detection values ​​of both photosensors PD1a and PD1b increase similarly during processing of workpieces 200 from the same lot, it is assumed that an abnormality (contamination) exists in the laser oscillator 10 serving as the light source or the protective glass SG1. The photosensors PD1a, PD1b, and PD1c are respectively disposed on boards CB1a, CB1b, and CB1c fixed to a portion of the periphery of the upper head block 61. In other words, the photosensors PD1a, PD1b, and PD1c are connected to the controller 70 so that the data signals of the detection values ​​of the photosensors PD1a, PD1b, and PD1c can be input to the controller 70 via the boards CB1a, CB1b, and CB1c, respectively.

[0065] In this way, the arrangement of the photosensor PD1 (i.e., photosensors PD1a, PD1b, and PD1c) provided in the upper head block 61 may cause the head processing unit 73 to determine that the detected value is on an increasing trend over a certain period of time. In this case, the head processing unit 73 can determine that there is a possibility of adverse effects on the optical fiber 30 and can notify an operator or the like by displaying the determination result on the display DP1. On the other hand, the arrangement of the photosensor PD1 (i.e., photosensors PD1a, PD1b, and PD1c) may cause the head processing unit 73 to determine that the detected value is on a decreasing trend over a certain period of time. In this case, the head processing unit 73 can determine that there is a possibility of a deterioration in the characteristics of the laser oscillator 10 or a deterioration in the coating characteristics of the protective glass SG1 and can notify an operator or the like by displaying the determination result on the display DP1.

[0066] Instead of providing each of the photosensors PD1a, PD1b, and PD1c with sensitivity to light in different wavelength bands, a filter (not shown) having sensitivity to light in different wavelength bands may be disposed in front of each of the photosensors PD1a, PD1b, and PD1c having sensitivity to light in the same wavelength band. This makes it possible to dispose each of the photosensors PD1a, PD1b, and PD1c having sensitivity to light in substantially different wavelength bands, even if each of the photosensors PD1a, PD1b, and PD1c has sensitivity to light in the same wavelength band.

[0067] The lower head block 62 accommodates, from top to bottom along the Z direction, a condenser lens FCL1, a photosensor PD2, and a protective glass SG2.

[0068] The condenser lens FCL1 has a function of condensing the laser light LB, which has been collimated by the collimation lens CLL1, toward the workpiece 200.

[0069] In this embodiment, for example, three photosensors PD2 are provided, and they are arranged to surround the protective glass SG2 in the XY plane directions perpendicular to the Z direction (see FIG. 5 ). Specifically, three photosensors PD2a, PD2b, and PD2c are arranged. Each of the photosensors PD2a, PD2b, and PD2c receives scattered light of the laser beam LB collimated by the collimation lens CLL1 in the upper head block 61, or light reflected from the workpiece 200 and scattered by the protective glass SG2 or the like in the lower head block 62. Each of the photosensors PD2a, PD2b, and PD2c may have light sensitivity to light in the same wavelength band or different wavelength bands. For example, photosensor PD2a may have broadband sensitivity to the output wavelength (e.g., 445 nm) of laser light LB, photosensor PD2b may have sensitivity only near the output wavelength (e.g., 445 nm) of laser light LB, and photosensor PD2c may have higher sensitivity to the infrared region (e.g., 900 nm) than the output wavelength (e.g., 445 nm) of laser light LB. Therefore, for example, if the detection value of photosensor PD2c increases, it is assumed that the reflected light state of the laser light based on the processing state of the workpiece 200 has changed. On the other hand, for example, if the detection values ​​of both photosensors PD2a and PD2b increase similarly during processing of workpieces 200 from the same lot, it is assumed that an abnormality (contamination) exists in the laser oscillator 10 serving as the light source or the protective glass SG2. Photosensors PD2a, PD2b, and PD2c are respectively disposed on substrates CB2a, CB2b, and CB2c fixed to a portion of the periphery of the lower head block 62. In other words, the photosensors PD2a, PD2b, and PD2c are connected to the controller 70 so that the data signals of the detection values ​​of each of the photosensors PD2a, PD2b, and PD2c can be input to the controller 70 via the boards CB2a, CB2b, and CB2c, respectively.

[0070] Instead of providing each of the photosensors PD2a, PD2b, and PD2c with sensitivity to light in different wavelength bands, a filter (not shown) having sensitivity to light in different wavelength bands may be disposed in front of each of the photosensors PD2a, PD2b, and PD2c having sensitivity to light in the same wavelength band. This makes it possible to dispose each of the photosensors PD2a, PD2b, and PD2c having sensitivity to light in substantially different wavelength bands, even if each of the photosensors PD2a, PD2b, and PD2c has sensitivity to light in the same wavelength band.

[0071] The protective glass SG2 is held at a predetermined position in a protective glass holder SH2 that has a rectangular shape in the XY plane and a constant thickness (Z direction) (see FIG. 5). The protective glass holder SH2 is formed so that it can be inserted into and removed from the lower head block 62 of the laser head 60 in the X direction. In other words, the protective glass SG2 can be easily replaced by placing it in the protective glass holder SH2 and inserting it into the lower head block 62.

[0072] In this way, the head processing unit 73 may determine that the detected value is on a decreasing trend for a certain period of time due to the arrangement of the photosensors PD2 (i.e., photosensors PD2a, PD2b, and PD2c) provided in the lower head block 62. In this case, the head processing unit 73 may determine that there is a possibility of a decrease in the characteristics of the laser oscillator or a deterioration in the coating characteristics of the protective glass SG1, and may notify an operator or the like by displaying the determination result on the display DP1.

[0073] 4. Operation for Detecting Abnormalities Inside the Laser Head Next, with reference to FIG. 7 , the operation of the head processing unit 73 for detecting the presence or absence of abnormalities inside the laser head 60 (for example, dirt, scratches, or deterioration) will be described. FIG. 7 is a flowchart showing the chronological order of the operation procedure for detecting the presence or absence of abnormalities inside the laser head 60 by the head processing unit 73 of the laser processing apparatus 100. The processes shown in FIG. 7 are mainly executed by the head processing unit 73. To simplify the explanation of FIG. 7 , threshold value 1 in the threshold value table TBL1 described with reference to FIG. 6 will be used as the upper limit threshold and threshold value 4 as the lower limit threshold, but threshold value 2 or threshold value 3 may also be used as the lower limit threshold.

[0074] 7, the head processing unit 73 obtains the average or maximum value of the detection values ​​of the photosensors PD1a, PD1b, and PD1c (see FIG. 4) as the detection value of the photosensor PD1 (see FIG. 3). Similarly, the head processing unit 73 obtains the average or maximum value of the detection values ​​of the photosensors PD2a, PD2b, and PD2c (see FIG. 4) as the detection value of the photosensor PD2 (see FIG. 3).

[0075] The head processing unit 73 determines whether the detection value of the photosensor PD1 is equal to or less than the upper threshold corresponding to the current operation program, oscillation mode, and laser beam LB output (command) based on the threshold table TBL1 read from the memory 71b (step St1). If the head processing unit 73 determines that the detection value of the photosensor PD1 is greater than the upper threshold (step St1, NO), it determines that there is a risk of damage to the optical elements inside the laser head 60 (e.g., around the upper head block 61) and controls the laser drive power supply (not shown) to stop operation of the laser processing apparatus 100, or generates a screen displaying a warning alarm (message) on the display DP1 urging the operator to clean or replace the optical elements (step St2). In other words, if the optical elements are burned, the AR coating applied to the optical elements will be damaged, which will increase the scattered light or cause intense light emission, thereby increasing the detection value of the photosensor PD1. After step St2, the processing of the head processing unit 73 shown in FIG. 7 ends.

[0076] On the other hand, if the head processing unit 73 determines that the detection value of the photosensor PD1 is equal to or less than the upper threshold (step St1, YES), it determines whether the detection value of the photosensor PD1 is equal to or greater than the lower threshold corresponding to the current operating program, oscillation mode, and laser beam LB command (step St3). If the head processing unit 73 determines that the detection value of the photosensor PD1 is less than the lower threshold (step St3, NO), it determines that an abnormality is likely occurring in the equipment located upstream of the laser head 60 (e.g., the laser oscillator 10, the optical unit 20, the optical fiber 30), and controls the turning off of the laser drive power supply (not shown) to stop operation of the laser processing apparatus 100, or generates a screen displaying a warning alarm (message) on the display DP1 to prompt the operator to inspect or replace the equipment (see above) (step St4). After step St4, the processing of the head processing unit 73 shown in FIG. 7 ends.

[0077] On the other hand, if the head processing unit 73 determines that the detection value of photosensor PD1 is equal to or greater than the lower threshold (step St3, YES), it determines that there is no abnormality in the detection value of photosensor PD1. Next, the head processing unit 73 determines whether the detection value of photosensor PD2 is equal to or less than the upper threshold corresponding to the current operation program, oscillation mode, and laser beam LB output (command) based on the threshold table TBL1 read from memory 71b (step St5). If the head processing unit 73 determines that the detection value of photosensor PD2 is greater than the upper threshold (step St5, NO), it determines that there is a risk of damage to the optical elements inside the laser head 60 (e.g., around the lower head block 62), and controls the turning off of the laser drive power supply (not shown) to stop operation of the laser processing apparatus 100, or generates a screen showing a warning alarm (message) on the display DP1 to prompt the operator to clean or replace the optical elements (step St6). After step St6, the process of the head processing unit 73 shown in FIG. 7 ends.

[0078] On the other hand, if the head processing unit 73 determines that the detection value of the photosensor PD2 is equal to or less than the upper threshold (step St5, YES), it determines whether the detection value of the photosensor PD2 is equal to or greater than the lower threshold corresponding to the current operating program, oscillation mode, and laser beam LB command (step St7). If the head processing unit 73 determines that the detection value of the photosensor PD2 is less than the lower threshold (step St7, NO), it determines that an abnormality is likely occurring in the equipment located upstream of the laser head 60 (e.g., the laser oscillator 10, the optical unit 20, the optical fiber 30), and controls the laser drive power supply (not shown) to stop operation of the laser processing apparatus 100, or generates a screen displaying a warning alarm (message) on the display DP1 to prompt the operator to inspect or replace the equipment (see above) (step St8). After step St8, the processing of the head processing unit 73 shown in FIG. 7 ends.

[0079] On the other hand, if the head processing unit 73 determines that the detection value of the photosensor PD2 is equal to or greater than the lower threshold value (step St7, YES), it determines that there is no abnormality in the detection value of the photosensor PD2.

[0080] After step St7, if the command from the laser control unit 71 to the laser oscillator 10 to emit the laser beam LB is on (i.e., ongoing) (step St9, YES), the processing of the head processing unit 73 returns to step St1. On the other hand, if the command from the laser control unit 71 to the laser oscillator 10 to emit the laser beam LB is not on (i.e., ongoing) (step St9, NO), the processing of the head processing unit 73 shown in FIG. 7 ends.

[0081] <Technology of the Present Disclosure> As described above, the present disclosure discloses the following technical ideas.

[0082] <Technology 1> A laser processing device including at least a laser oscillator (laser oscillator 10) that generates laser light, a laser head (laser head 60) that irradiates the laser light toward a workpiece (workpiece 200), and a control unit (laser control unit 71), wherein the laser head accommodates at least a first lens (collimation lens CLL1, condenser lens FCL1) for focusing the laser light toward the workpiece, a first glass (protective glass SG1, SG2) that transmits the laser light, and one or more first sensors (photo sensors PD1, PD2) that are arranged between the first lens and the first glass in the irradiation direction of the laser light toward the workpiece, and the control unit detects the presence or absence of an abnormality in at least one of the first lens and the first glass based on the detection output of the first sensor. This allows the laser processing device to easily detect whether or not there are any abnormalities (e.g., dirt, scratches, or deterioration) in the optical elements inside the laser head 60 by making a judgment using the detection output of the photosensor PD1 or photosensor PD2 located inside the laser head 60, which irradiates the laser beam (i.e., laser light LB) toward the workpiece 200.

[0083] <Technology 2> The laser head further accommodates a second lens (condensing lens FCL1, collimation lens CLL1) for focusing the laser light toward the workpiece, a second glass (protective glass SG2, SG1) that transmits the laser light, and one or more second sensors (photo sensors PD2, PD1) arranged between the second lens and the second glass in the irradiation direction of the laser light toward the workpiece, and the control unit further detects the presence or absence of an abnormality in at least one of the second lens and the second glass based on the detection output of the second sensor. As a result, the laser processing device can easily and precisely detect the presence or absence of an abnormality (e.g., dirt, scratches, deterioration) in optical elements etc. inside the laser head 60 by determining using the detection output of the photosensor PD2 or PD1 arranged inside the laser head 60, even if photosensors are arranged at multiple locations inside the laser head 60, based on the detection output of the photosensor corresponding to the arrangement location.

[0084] <Technology 3> The laser processing apparatus according to Technology 1 or Technology 2, wherein the control unit displays on a display (display DP1) a detection result of the presence or absence of an abnormality in at least one of the first lens and the first glass. This allows an operator operating the laser processing apparatus to visually confirm and understand the detection result of the presence or absence of an abnormality (e.g., dirt, scratches, or deterioration) in at least one of the first lens (collimation lens CLL1, condenser lens FCL1) and the first glass (protective glasses SG1, SG2).

[0085] <Technology 4> The laser processing device according to Technology 1, wherein a plurality of the first sensors are arranged to surround the first glass when viewed in a plane direction orthogonal to the direction of irradiation of the laser light onto the workpiece. This allows the laser processing device to multifacetedly and comprehensively determine the presence or absence of an abnormality (e.g., dirt, scratches, or deterioration) in the first glass (protective glass SG1, SG2) based on the detection outputs of the plurality of first sensors (photo sensors PD1, PD2).

[0086] <Technology 5> The laser processing device according to Technology 2, wherein a plurality of the second sensors are arranged to surround the second glass when viewed in a plane direction orthogonal to the direction of irradiation of the laser light onto the workpiece. This allows the laser processing device to multifacetedly and comprehensively determine the presence or absence of abnormalities (e.g., dirt, scratches, deterioration) not only in the first glass (protective glass SG1, SG2) but also in the second glass (protective glass SG2, SG1) based on the detection outputs of the plurality of second sensors (photo sensors PD2, PD1).

[0087] <Technology 6> The laser processing device according to any one of Technologies 1 to 5, wherein the control unit detects the presence or absence of an abnormality in at least one of the first lens and the first glass based on a comparison between the detection output of the first sensor and a threshold value (threshold value 5) that is a normal detection value of the first sensor. This allows the laser processing device to easily and appropriately detect the presence or absence of an abnormality (e.g., dirt, scratches, deterioration) in optical elements and the like inside the laser head 60 by making a determination based on a comparison between the detection outputs of photosensors PD1 and PD2 arranged inside the laser head 60 that irradiates the laser beam (i.e., laser light LB) toward the workpiece 200 and the threshold value.

[0088] <Technology 7> The laser processing apparatus according to Technology 1, wherein the first glass is disposed on an upper side of the laser head and between an optical fiber (optical fiber 30) that guides the laser light from the laser oscillator and the first lens, the first lens is a collimation lens (collimation lens CLL1) that collimates the laser light that has passed through the first glass, and the control unit detects the presence or absence of an abnormality in at least one of the first glass and the collimation lens based on the detection output of the first sensor. This allows the laser processing apparatus to appropriately detect the presence or absence of an abnormality (e.g., dirt, scratches, or deterioration) in at least one of the protective glass SG1 that is disposed on the upper side of the laser head 60 and between the optical fiber 30 and the collimation lens CLL1 and the collimation lens CLL1.

[0089] <Technology 8> The laser processing apparatus according to Technology 2, wherein the second lens is a condenser lens (condenser lens FCL1) that condenses the laser light LB that has passed through the first lens (collimation lens CLL1) toward the workpiece, the second glass is a protective glass (protective glass SG2) that is arranged on the lower side of the laser head and that prevents scattered deposits (e.g., fumes and sputters) from entering the interior of the laser head, and the control unit detects the presence or absence of an abnormality in at least one of the protective glass and the condenser lens based on the detection output of the second sensor. This allows the laser processing apparatus to appropriately detect the presence or absence of an abnormality (e.g., dirt, scratches, or deterioration) in at least one of the protective glass SG2 that is arranged on the lower side of the laser head 60 and that prevents scattered deposits from the workpiece 200 from entering the interior of the laser head 60, and the condenser lens FCL1.

[0090] <Technology 9> The laser processing apparatus according to Technology 4, wherein the plurality of first sensors each have detection sensitivity to the laser light in a different wavelength band. As a result, the laser processing apparatus can receive scattered light, etc. of the laser light LB with high sensitivity over a wide wavelength band by having the plurality of first sensors (e.g., photosensors PD1a, PD1b, PD1c) each have detection sensitivity to the laser light LB in a different wavelength band, and can accurately detect the presence or absence of abnormalities (e.g., dirt, scratches, deterioration) inside the laser head 60 (particularly in the vicinity of the upper head block 61).

[0091] <Technology 10> The laser processing apparatus according to Technology 5, wherein the plurality of second sensors each have detection sensitivity to the laser light in a different wavelength band. As a result, the laser processing apparatus can receive scattered light, etc. of the laser light LB with high sensitivity over a wide wavelength band by having the plurality of second sensors (e.g., photosensors PD2a, PD2b, PD2c) each have detection sensitivity to the laser light LB in a different wavelength band, and can accurately detect the presence or absence of an abnormality (e.g., dirt, scratches, deterioration) inside the laser head 60 (particularly in the vicinity of the lower head block 62).

[0092] <Technology 11> The laser processing device according to any one of Technologies 1 to 10, wherein the laser light is blue laser light having a blue wavelength band. As a result, when performing laser processing using blue laser light (blue laser beam), the laser processing device can easily detect the presence or absence of abnormalities (e.g., dirt, scratches, deterioration) in optical elements and the like inside the laser head 60 by determining using the detection output of the photosensor PD1 or PD2 arranged inside the laser head 60 that irradiates the laser beam (i.e., laser light LB) toward the workpiece 200.

[0093] and detecting, by the control unit, the presence or absence of an abnormality in at least one of the first lens and the first glass based on the detection output of the first sensor. Thus, according to the laser head contamination detection method, the presence or absence of an abnormality (e.g., dirt, scratches, or deterioration) in an optical element or the like inside the laser head 60 can be easily detected by determining the detection output of a photosensor PD1 or PD2 disposed inside the laser head 60 that irradiates a laser beam (i.e., laser light LB) toward a workpiece 200.

[0094] Although various embodiments have been described above with reference to the drawings, it goes without saying that the present disclosure is not limited to such examples. It is clear that a person skilled in the art can conceive of various modifications, alterations, substitutions, additions, deletions, and equivalents within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present disclosure. Furthermore, the components of the various embodiments described above may be combined in any manner without departing from the spirit of the invention.

[0095] In the above-described embodiment, an example in which threshold value 4 is set as the lower threshold value has been described, but two levels of lower threshold value may be set, and the head processing unit 73 may determine whether the value is below the lower threshold value based on a comparison with a past log (for example, past detection values ​​of photosensors PD1 and PD2 for a certain period (for example, one month ago) stored in memory 74) instead of or in addition to the lower threshold value. This allows the head processing unit 73 to perform a detailed analysis to determine whether the abnormality is due to a change over time or a sudden change, and for example, by comparing it with monitoring data of the laser oscillator 10 stored in memory 74, it becomes possible to perform a detailed cause analysis.

[0096] This application is based on a Japanese patent application (Patent Application No. 2023-218463) filed on December 25, 2023, the contents of which are incorporated herein by reference.

[0097] The present disclosure is useful as a laser processing apparatus and a laser head abnormality detection method that easily detects the presence or absence of an abnormality in an optical element or the like inside a laser head that irradiates a laser beam toward a workpiece.

[0098] REFERENCE SIGNS LIST 10 Laser oscillator 20 Optical unit 21 Housing 22 Condenser lens 30 Optical fiber 50 XY stage 60 Laser head 61 Upper head block 62 Lower head block 71 Laser control unit 72 Stage control unit 73 Head processing unit 74 Memory 100 Laser processing device 200 Workpiece DP1 Display PD1, PD2 Photosensor SG1, SG2 Protective glass SH1, SH2 Protective glass holder

Claims

1. A laser processing apparatus comprising at least a laser oscillator that generates laser light, a laser head that irradiates the laser light toward a workpiece, and a control unit, wherein the laser head houses at least a first lens for condensing the laser light toward the workpiece, a first glass that transmits the laser light, and one or more first sensors disposed between the first lens and the first glass in the irradiation direction of the laser light onto the workpiece, and the control unit detects the presence or absence of an abnormality in at least one of the first lens and the first glass based on the detection output of the first sensor.

2. The laser processing apparatus according to claim 1, wherein the laser head further houses a second lens for condensing the laser light toward the workpiece, a second glass that transmits the laser light, and one or more second sensors disposed between the second lens and the second glass in the irradiation direction of the laser light onto the workpiece, and the control unit further detects the presence or absence of an abnormality in at least one of the second lens and the second glass based on the detection output of the second sensor.

3. The laser processing apparatus according to claim 1, wherein the control unit displays the detection result of the presence or absence of an abnormality in at least one of the first lens and the first glass on a display.

4. The laser processing apparatus according to claim 1, wherein a plurality of the first sensors are arranged to surround the first glass when viewed in a plane direction orthogonal to the irradiation direction of the laser light onto the workpiece.

5. The laser processing apparatus according to claim 2, wherein a plurality of the second sensors are arranged to surround the second glass when viewed in a plane direction orthogonal to the irradiation direction of the laser light onto the workpiece.

6. The laser processing apparatus according to claim 1, wherein the control unit detects the presence or absence of an abnormality in at least one of the first lens and the first glass based on a comparison between the detection output of the first sensor and a threshold value which is a normal detection value of the first sensor.

7. The first glass is disposed between the upper side of the laser head and an optical fiber that guides the laser light from the laser oscillator and the first lens. The first lens is a collimation lens that collimates the laser light transmitted through the first glass. The control unit detects the presence or absence of an abnormality in at least one of the first glass and the collimation lens based on the detection output of the first sensor. The laser processing apparatus according to claim 1.

8. The second lens is a condenser lens that condenses the laser light transmitted through the first lens toward the workpiece. The second glass is a protective glass that is disposed on the lower side of the laser head and suppresses the entry of scattered deposits from the workpiece into the laser head. The control unit detects the presence or absence of an abnormality in at least one of the protective glass and the condenser lens based on the detection output of the second sensor. The laser processing apparatus according to claim 2.

9. The plurality of first sensors each have a detection sensitivity for the laser light in a different wavelength band. The laser processing apparatus according to claim 4.

10. The plurality of second sensors each have a detection sensitivity for the laser light in a different wavelength band. The laser processing apparatus according to claim 5.

11. The laser light is blue laser light having a blue wavelength band. The laser processing apparatus according to any one of claims 1 to 10.

12. A laser head abnormality detection method executed by a laser processing apparatus including at least a laser oscillator that generates laser light, a laser head that irradiates the laser light toward a workpiece, and a control unit. The laser head includes at least a first lens for condensing the laser light toward the workpiece, a first glass that transmits the laser light, and one or more first sensors disposed between the first lens and the first glass in the irradiation direction of the laser light to the workpiece. The method includes a step of acquiring, by the control unit, the detection output of the first sensor, and a step of detecting, by the control unit, the presence or absence of an abnormality in at least one of the first lens and the first glass based on the detection output of the first sensor. A laser head abnormality detection method.

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