Control device, laser processing head, laser processing apparatus, laser processing system, and laser processing method

Abstract

The control device (10) includes: a data acquisition unit that acquires a reflected light irradiation position, which is an incident position where a part of the reflected light (RL) obtained by reflecting the laser light (L) incident from the fiber end (1) of the optical fiber (7) on the object to be processed (W) enters the photodetector (6-1) serving as a reflected light sensor, and the amount of the reflected light (RL) entering the photodetector (6-1) serving as a reflected light sensor; and a reflected light estimation unit that estimates the amount of the fiber reflected light, which is another part of the reflected light (RL) and enters the fiber end (1).

Description

Technical Field

[0001] The present disclosure relates to a control device for laser processing, a laser processing head, a laser processing apparatus, a laser processing system, and a laser processing method that perform processing using laser light transmitted through an optical fiber.

Background Art

[0002] In a laser processing apparatus that performs laser processing by irradiating a processing object with laser light transmitted through an optical fiber, when the laser light reflected by the processing object enters the fiber end of the optical fiber, it may lead to damage to the oscillator. For this reason, methods for detecting the reflected light have been studied.

[0003] For example, Patent Document 1 discloses a technique in which laser light emitted from a fiber end is made to enter a bend mirror, the reflected light from the bend mirror is irradiated onto a processing object, and the light transmitted through the bend mirror among the reflected light from the processing object is made to enter an absorber, and the amount of scattered light from the absorber is detected by light detection means.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, according to the above conventional technique, although it is possible to detect the amount of reflected light from the processing object, since not all of the reflected light enters the fiber end, there is a problem that the amount of reflected light entering the fiber end cannot be grasped.

[0006] The present disclosure has been made in view of the above, and an object thereof is to obtain a control device capable of grasping the amount of reflected light incident on the fiber end.

Means for Solving the Problem

[0007] In order to solve the above-described problems and achieve the object, the control device of the present disclosure includes a data acquisition unit that acquires a reflected light irradiation position, which is an incident position where a part of the reflected light obtained by reflecting the laser light incident from the fiber end of the optical fiber on the object to be processed enters the reflected light sensor, and the light amount of the reflected light entering the reflected light sensor, and a reflected light estimation unit that estimates the light amount of the fiber reflected light, which is another part of the reflected light and is the reflected light entering the fiber end, based on the reflected light irradiation position and the light amount of the reflected light entering the reflected light sensor.

Advantages of the Invention

[0008] According to the present disclosure, there is an effect that it becomes possible to grasp the light amount of the reflected light incident on the fiber end.

Brief Description of the Drawings

[0009]

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Embodiments for Carrying Out the Invention

[0010] Hereinafter, a control device, a laser processing head, a laser processing apparatus, a laser processing system, and a laser processing method according to embodiments of the present disclosure will be described in detail with reference to the drawings.

[0011] Embodiment 1. FIG. 1 is a diagram showing a configuration example of a laser processing system 100 according to Embodiment 1. The laser processing system 100 includes a control device 10 that controls the laser processing system 100, a laser processing head 20 that irradiates a processing target W with a processing laser beam L, an oscillator 8 that supplies the processing laser beam L to the laser processing head 20, and an optical fiber 7 that transmits the laser beam L emitted from the oscillator 8 to the laser processing head 20.

[0012] The laser processing system 100 performs laser processing such as cutting, welding, and additive manufacturing. The control device 10 and the laser processing head 20 together are referred to as a laser processing apparatus. In the following description, the surface of a table (not shown) on which the processing target W is placed is defined as the xy plane, and the laser processing head 20 is arranged at a distance in the z-axis direction with respect to the processing target W. The traveling direction of the laser beam L from the optical fiber 7 is the -x direction.

[0013] The oscillator 8 generates a laser beam L for processing. The laser beam L generated by the oscillator 8 is transmitted through the optical fiber 7 and emitted from the fiber end 1 into the laser processing head 20. The type of the oscillator 8 is not particularly limited as long as it can generate the laser beam L. For example, the oscillator 8 may be a fiber laser oscillator, a direct diode laser, or a solid-state laser using a YAG crystal or the like as an excitation medium. Further, the laser processing system 100 may include a wavelength conversion unit that converts the wavelength of the laser beam L generated from the oscillator 8. The wavelength conversion unit may be provided inside the oscillator 8 or outside the oscillator 8.

[0014] The control device 10 has a function of controlling the operation of the laser processing system 100 by controlling the operating conditions of the oscillator 8 and the laser processing head 20.

[0015] The laser processing head 20 performs laser processing on the workpiece W by irradiating the workpiece W with the laser beam L supplied from the oscillator 8 via the optical fiber 7. The laser processing head 20 includes a drive mechanism (not shown) and can change the relative position with respect to the workpiece W. Here, it is assumed that the laser processing head 20 moves, but the position of the laser processing head 20 may be fixed, and the table on which the workpiece W is placed may move, or both the laser processing head 20 and the table may move. Inside the laser processing head 20, a processing gas is supplied, and when the laser beam L is irradiated onto the workpiece W, the processing gas is jetted onto the workpiece W.

[0016] The laser processing head 20 includes a collimating lens 2, a folding mirror 3, a focusing lens 4, an imaging optical system position changing drive unit 41, imaging lenses 5-1 and 5-2, and photodetectors 6-1 and 6-2. The collimating lens 2 makes the laser beam L incident from the fiber end 1 into a parallel beam when it enters the laser processing head 20. The folding mirror 3 is a partial reflection mirror, which transmits a part of the laser beam L incident from the fiber end 1 and transmitted through the collimating lens 2, and reflects the other part, thereby branching the laser beam L into light traveling in two optical paths. The focusing lens 4 focuses the laser beam L reflected by the folding mirror 3 onto the workpiece W. The laser processing head 20 has a processing nozzle that irradiates the workpiece W with the laser beam L focused by the focusing lens 4. The processing nozzle has an opening on the optical path between the focusing lens 4 and the workpiece W, and the laser beam L and the processing gas pass through the opening. The imaging optical system position changing drive unit 41 is a drive unit that changes the positional relationship between the irradiation position of the focusing lens 4, which is an imaging optical system, and the workpiece W.

[0017] The imaging lens 5-1 forms an image of a part of the reflected light RL reflected by the workpiece W on the photodetector 6-1. The reflected light RL incident on the imaging lens 5-1 is a part of the light that is reflected by the workpiece W and transmitted through the focusing lens 4, and is the reflected light RL transmitted through the folding mirror 3. The imaging lens 5-1 is a reflected light imaging lens that forms an image of a part of the reflected light RL.

[0018] The photodetector 6-1 is a reflected light sensor that detects the reflected light RL from the workpiece W. The photodetector 6-1 detects the reflected light irradiation position, which is the incident position of the reflected light RL incident on the photodetector 6-1 through the folding mirror 3 and the imaging lens 5-1, and the light amount of the reflected light RL incident on the photodetector 6-1. The photodetector 6-1 outputs the detected reflected light irradiation position and the light amount of the reflected light RL to the control device 10.

[0019] The imaging lens 5-2 forms an image of a part of the laser beam L incident on the laser processing head 20 from the fiber end 1 on the photodetector 6-2. The laser beam L incident on the imaging lens 5-2 is a part of the laser beam L that has passed through the collimating lens 2 and has passed through the folding mirror 3. The imaging lens 5-2 is an incident light imaging lens that forms an image of a part of the incident light on the laser processing head 20.

[0020] The photodetector 6-2 is an incident light sensor that detects the laser beam L, which is the incident light on the laser processing head 20. The photodetector 6-2 detects the incident light irradiation position, which is the incident position of the laser beam L incident on the photodetector 6-2 via the folding mirror 3 and the imaging lens 5-2, and the light amount of the laser beam L incident on the photodetector 6-2. The photodetector 6-2 outputs the detected incident light irradiation position and the light amount of the laser beam L to the control device 10.

[0021] The photodetectors 6-1 and 6-2 preferably can measure the irradiation position and the light amount of the incident light and have a high measurement speed. For example, the photodetectors 6-1 and 6-2 are a four-segment photodiode, a CMOS (Complementary Metal-Oxide-Semiconductor) camera, or the like. Also, here, since it is desired to measure the reflected light RL or the laser beam L, it is desirable to extract only the oscillation wavelength of the laser beam L using an optical filter such as a band-pass filter. The optical filter such as a band-pass filter may be built into the photodetectors 6-1 and 6-2, or may be separately provided on the optical path in front of the photodetectors 6-1 and 6-2.

[0022] The laser beam L that enters the laser processing head 20 from the fiber end 1 via the optical fiber 7 from the oscillator 8 is irradiated onto the workpiece W through the collimating lens 2, the bending mirror 3, and the focusing lens 4. Also, in the bending mirror 3, a part of the laser beam L is branched toward the imaging lens 5-2 side and imaged on the photodetector 6-2 by the imaging lens 5-2. Further, a part of the laser beam L irradiated onto the workpiece W becomes the reflected light RL and enters the bending mirror 3 through the focusing lens 4. The reflected light RL that has entered the bending mirror 3 branches into the light that transmits to the imaging lens 5-1 side and the light that is reflected and travels toward the fiber end 1 side. The reflected light RL that has entered the imaging lens 5-1 is imaged on the photodetector 6-1. The reflected light RL that is reflected toward the fiber end 1 side travels toward the fiber end 1 side through the collimating lens 2. Depending on the traveling angle of the reflected light RL, the reflected light RL that has passed through the collimating lens 2 enters the fiber end 1. The reflected light RL may lead to damage to the optical components of the laser processing head 20, and when it enters the fiber end 1, it may lead to a failure of the oscillator 8. Hereinafter, the reflected light RL that enters the fiber end 1 may be referred to as the fiber reflected light.

[0023] Figure 2 is an explanatory diagram of laser processing when the processing state is good. Figure 3 is an explanatory diagram of laser processing when a non-penetrating state has occurred. The absorption rate of the laser beam L with respect to the wavelength for metal is lower in the solid state compared to the molten metal. For this reason, in a good processing state, as shown in Figure 2, molten metal is generated and the laser beam L travels in the optical axis direction of the laser beam L, so the intensity of the reflected light RL to the laser processing head 20 is not high. However, for example, when appropriate processing conditions are not set and the processing state deteriorates, as shown in Figure 3, the laser beam L does not penetrate the workpiece W and is reflected by the workpiece W, increasing the intensity of the reflected light RL.

[0024] There is a correlation between the reflected light irradiation position detected by the photodetector 6-1, the amount of light of the reflected light RL, and the amount of light of the fiber reflected light. The reflected light RL is branched by the bending mirror 3 into light traveling toward the photodetector 6-1 side and light traveling toward the fiber end 1 side, and the branching ratio is determined by the characteristics and arrangement of the bending mirror 3. Therefore, by detecting the amount of light of the reflected light RL with the photodetector 6-1, the amount of light of the reflected light RL traveling toward the fiber end 1 side can be grasped. Further, depending on the state of the surface of the workpiece W and the like, the angle at which the reflected light RL enters the condenser lens 4 and the bending mirror 3 changes. Depending on the angle at which the reflected light RL enters the bending mirror 3, both the incident position of the reflected light RL on the yz plane at the position of the fiber end 1 in the x-axis direction and the reflected light irradiation position change. There is a correlation between the incident position of the reflected light RL on the yz plane at the position of the fiber end 1 in the x-axis direction and the reflected light irradiation position, and by detecting the reflected light irradiation position with the photodetector 6-1, the range irradiated by the reflected light RL on the yz plane at the position of the fiber end 1 can be grasped. Therefore, it becomes possible to grasp the ratio of the fiber reflected light among the reflected light RL that has traveled from the bending mirror 3 toward the fiber end 1 side. Therefore, by the photodetector 6-1 detecting the reflected light irradiation position and the amount of light of the reflected light RL, it becomes possible to grasp the amount of light of the fiber reflected light.

[0025] Also, there is a correlation between the incident light irradiation position detected by the photodetector 6-2, the amount of light of the laser light L, and the amount of light of the fiber reflected light. The incident light irradiation position changes when the arrangement of the optical system in the laser processing head 20 is adjusted, or changes over time. Therefore, by using the detection data of the photodetector 6-2, it becomes possible for the control device 10 to correct the influence of changes over time.

[0026] Note that the arrangement of the optical system shown in Fig. 1 is an example, and various modifications can be made. For example, the collimating lens 2 and the imaging optical system may be single lenses as shown in Fig. 1, or may be multiple lenses. Further, the laser processing head 20 may include a zoom optical system that changes the imaging diameter of the imaging point by displacing the position of the optical system. Also, the laser processing head 20 may include an optical system that displaces the irradiation position by adjusting the divergence angle at which the collimating lens 2 is displaced and enters the imaging optical system, by means of the imaging optical system position changing drive unit 41. The optical component driven by the imaging optical system position changing drive unit 41 may be of one type or two or more types. The irradiation position may be at the beam waist position of the optical system or may be offset from the beam waist position. When changing the positional relationship between the imaging point of the laser beam L and the workpiece W without changing the positional relationship in the height direction, that is, in the z-axis direction of Fig. 1, between the laser processing head 20 and the workpiece W, it is possible to achieve this by displacing the condenser lens 4, which is the imaging optical system, by means of the imaging optical system position changing drive unit 41. The imaging optical system may be a condensing optical system. Also, the imaging lenses 5-1, 5-2 may be fθ lenses.

[0027] The control device 10 controls the oscillator 8, the laser processing head 20, and a drive unit (not shown) based on processing parameters, which are numerical parameters related to laser processing, to execute laser processing. Specifically, the control device 10 controls a motor drive unit (not shown), and the motor drive unit drives a motor according to the control of the control device 10, whereby the relative position between the laser processing head 20 and the workpiece W can be changed. Also, the control device 10 can control the laser processing by adjusting various processing conditions.

[0028] FIG. 4 is a diagram showing a functional configuration example of the control device 10 according to the first embodiment. The control device 10 includes a data acquisition unit 11, a reflected light estimation unit 12, and a control unit 13. The data acquisition unit 11 acquires data indicating the state of the laser processing system 100 from each part of the laser processing system 100. Specifically, the data acquired by the data acquisition unit 11 includes the reflected light irradiation position and the amount of the reflected light RL output by the photodetectors 6-1 and 6-2, and the incident light irradiation position and the amount of the laser light L. Although not shown, the data acquisition unit 11 may acquire detection data acquired by sensors other than the photodetectors 6-1 and 6-2, and other information other than the data acquired by the photodetectors 6-1 and 6-2, such as the processing conditions of the laser processing. Depending on the type of the acquired information, the data acquisition unit 11 can convert the acquired information into a time-series signal.

[0029] The reflected light estimation unit 12 estimates the amount of the fiber reflected light based on the data acquired by the data acquisition unit 11. The reflected light estimation unit 12 may have a feature amount extraction function. In this case, the reflected light estimation unit 12 can extract a feature amount from the data acquired by the data acquisition unit 11.

[0030] FIG. 5 is an explanatory diagram of the function of the reflected light estimation unit 12. A imaging lens 5-1 is disposed in front of the photodetector 6-1. Assuming that the focal length of the imaging lens 5-1 is f and the angle formed by the reflected light RL and the imaging lens 5-1 is θ, the irradiation position of the reflected light RL on the photodetector 6-1 is ftanθ. Thereby, the reflected light estimation unit 12 can obtain the relationship between the angles of the laser beam L and the reflected light RL. Further, based on this angle information, the reflected light estimation unit 12 calculates the angle of the reflected light RL incident on the collimating lens 2, and from information such as the distance to the fiber end 1, the arrangement of the optical system of the collimating lens 2, and conditions such as the laser output, the amount of the reflected light RL with respect to the angle of the fiber reflected light can be obtained. Based on the amount of the reflected light RL obtained by the reflected light estimation unit 12, it becomes possible to determine whether the reflected light RL reaching the fiber end 1 contributes to a failure of the oscillator 8 or the like. The reflected light estimation unit 12 outputs the obtained amount of the reflected light RL to the control unit 13. Note that if the secular change of the optical axis of the laser beam L is small and detection is not necessary, the photodetector 6-2 may be omitted.

[0031] Returning to the description of FIG. 4. The reflected light estimation unit 12 can estimate the amount of the fiber reflected light based on at least the reflected light irradiation position and the amount of the reflected light RL. Further, the reflected light estimation unit 12 can use, for example, processing parameters, temperature information of the processing optical system inside the laser processing head 20, temperature change of the processing optical system inside the laser processing head 20, processed plate thickness, information on the processed material, and the like.

[0032] Note that the reflected light estimation unit 12 may output the estimation result to an output unit such as a display device inside or outside the laser processing system 100. Regardless of the amount of the obtained reflected light RL, the reflected light estimation unit 12 may output the estimation result, or may output the estimation result only when it is determined that the amount of the obtained reflected light RL may cause a failure of the oscillator 8 during processing. When it is determined that there is a possibility of causing a failure of the oscillator 8, the reflected light estimation unit 12 can output a warning. The reflected light estimation unit 12 may display the estimation result on the display screen of the display device, or may output the estimation result by voice output from a voice output device such as a speaker. Further, when it is determined that there is a possibility of causing a failure of the oscillator 8, the reflected light estimation unit 12 may express a warning by lighting a pat lamp.

[0033] The control unit 13 can control the movement of the entire laser processing system 100. At this time, the control unit 13 can control the laser processing system 100 based on the amount of light obtained by the reflected light estimation unit 12, that is, the amount of light of the fiber reflected light. Specifically, the control unit 13 has the function of an operating condition changing unit that changes the operating conditions of the laser processing system 100 based on the amount of the fiber reflected light. At this time, the control unit 13 changes the operating conditions so that the amount of the fiber reflected light decreases. The operating conditions are those obtained by adding conditions not used during normal processing to the processing conditions that are conditions related to processing. For example, if there is a component such as a mechanical shutter in the oscillator 8 that can physically block the reflected light RL, measures such as shielding are also included in the operating conditions. The processing conditions include, for example, laser output, beam quality of the laser beam L, processing gas pressure, processing speed, irradiation position of the imaging optical system, imaging diameter of the imaging optical system, pulse frequency of the laser beam L, duty ratio of the pulse of the laser beam L, magnification of the imaging optical system of the laser beam L, nozzle diameter of the nozzle provided in the laser processing head 20, distance between the processing object W and the nozzle, type of mode of the laser beam L, positional relationship between the center of the opening of the nozzle and the laser beam L, and the like.

[0034] When the control unit 13 determines that there is a possibility of damaging the oscillator 8 based on the amount of the fiber reflected light obtained by the reflected light estimation unit 12, it adjusts the operating conditions. Otherwise, it continues the control under the current operating conditions. Whether there is a possibility of damaging the oscillator 8 is determined using, for example, a threshold value for the light amount. The threshold value may be changed according to processing conditions such as the plate thickness and the material of the object W to be processed. Further, the control unit 13 may adjust the operating conditions using a model such as changing the adjustment amount of the operating conditions based on the light amount. Alternatively, the control unit 13 may determine the operating conditions using an evaluation formula with the reflected light irradiation position and the light amount detected by the photodetector 6-1 as explanatory variables. For example, the model used by the control unit 13 may be a model that outputs an evaluation value such as the degree of change over time. When adjusting the operating conditions, the control unit 13 can determine the adjustment content of the processing conditions, for example, the adjustment amount, based on the estimated value of the light amount output by the reflected light estimation unit 12 and the current operating conditions. In adjusting the operating conditions, the control unit 13 adjusts the operating conditions so that the amount of the fiber reflected light decreases. For example, the adjustment content of the operating conditions for reducing the amount of the fiber reflected light includes lowering the laser output, slowing down the processing speed, turning off the power supply of the oscillator 8, physically blocking the emission of the laser light L with a mechanical shutter provided in the oscillator 8, increasing the distance between the nozzle and the object W to be processed, and the like. Slowing down the processing speed can result in reducing the amount of the reflected light RL by allowing the molten metal to flow downward and penetrate. By increasing the distance between the nozzle and the object W to be processed, the light incident on the laser processing head 20 among the reflected light RL reflected by the object W to be processed can be reduced.

[0035] FIG. 6 is a flowchart for explaining an operation example of the control device 10 according to Embodiment 1. FIG. 6 shows an operation for changing the operation conditions of the laser processing system 100. When starting the operation of FIG. 6, it is assumed that the oscillator 8 has already been started and laser processing is being executed. The data acquisition unit 11 of the control device 10 acquires sensor data from the photodetectors 6-1 and 6-2 (step S101). The data acquisition unit 11 acquires the reflected light irradiation position, the light amount of the reflected light RL, the incident light irradiation position, and the light amount of the laser light L which is the incident light from the sensor data (step S102). The data acquisition unit 11 outputs the acquired data to the reflected light estimation unit 12. As described above, the data acquisition unit 11 may acquire sensor data from sensors other than the photodetectors 6-1 and 6-2, or may acquire data other than sensor data.

[0036] Based on the data acquired by the data acquisition unit 11, the reflected light estimation unit 12 estimates the light amount of the fiber reflected light which is the reflected light RL incident on the fiber end 1 (step S103). Based on the light amount of the reflected light RL incident on the fiber end 1 estimated by the reflected light estimation unit 12, the control unit 13 determines whether there is a possibility of damage to the oscillator 8 (step S104). If there is a possibility of damage (step S104: Yes), the control unit 13 adjusts the operation conditions to suppress the reflected light RL (step S105). Here, suppressing the reflected light RL includes suppressing the reflected light RL itself reflected by the workpiece W, and also includes suppressing the light amount of the reflected light RL incident on the fiber end 1 among the reflected light RL although the light amount of the reflected light RL itself reflected by the workpiece W does not change. After adjusting the operation conditions, the control device 10 returns to the operation of step S101.

[0037] If it is determined that there is no possibility of damage (step S104: No), the control unit 13 continues the processing under the current operation conditions (step S106) and returns to the operation of step S101.

[0038] Through the above processing, the correction of the operation conditions is repeated until the estimated value of the light amount of the reflected light RL output by the reflected light estimation unit 12 is determined to have no possibility of damaging the oscillator 8.

[0039] As described above, according to the first embodiment, a data acquisition unit 11 that acquires a reflection light irradiation position, which is an incident position where a part of the reflected light RL reflected by the processing object W of the laser light L incident from the fiber end 1 of the optical fiber 7 enters the photodetector 6-1 serving as a reflection light sensor, and the light amount of the reflected light RL entering the photodetector 6-1 serving as a reflection light sensor, and a reflection light estimation unit 12 that estimates the light amount of the fiber reflection light, which is another part of the reflected light RL and is the reflected light RL incident on the fiber end 1, based on the reflection light irradiation position and the light amount of the reflected light RL entering the photodetector 6-1 serving as a reflection light sensor, can be provided.

[0040] Since the reflection light irradiation position detected by the photodetector 6-1 is correlated with the irradiation position of the reflected light RL at the position of the fiber end 1, by detecting the reflection light irradiation position, it becomes possible to grasp the light amount of the light that the reflected light RL reflected by the processing object W enters the fiber end 1. When only the light amount of the reflected light RL is detected by the photodetector 6-1, even if the light amount of the reflected light RL reaching the position of the fiber end 1 can be grasped, depending on the angle of the reflected light RL, it may be light that does not enter the fiber end 1. In the control device 10, since the light amount of the light entering the fiber end 1 can be grasped, it becomes possible to take measures such as interrupting the processing only when it is really necessary. Therefore, the stop time of the processing can be shortened and the productivity can be improved. The optical fiber 7 has a part called a core layer and a cladding layer outside the core layer, and by adjusting the refractive indices of the cladding layer and the core layer, light is propagated through the core layer at the center. The emission angle of the light emitted from the core layer can be defined by the maximum incident and emission angle NA at which light (propagation mode) that can be propagated through the optical fiber 7 is incident or can be emitted from the optical fiber 7. When there are a plurality of core layers, it is called a multi-core fiber. The reflected light RL mentioned here may be the light amount irradiated on the core layer or the light amount irradiated on the cladding. Also, the technology of the present disclosure can be applied whether the optical fiber 7 is a multi-core fiber or a single fiber.

[0041] Further, the data acquisition unit 11 acquires the incident light irradiation position, which is the incident position where a part of the laser light L is incident on the photodetector 6-2 serving as the incident light sensor, and the amount of the laser light L incident on the photodetector 6-2 serving as the incident light sensor. The reflected light estimation unit 12 may estimate the amount of the fiber reflected light based on the amount of the reflected light RL incident on the photodetector 6-1 serving as the reflected light sensor, the amount of the laser light L incident on the photodetector 6-2 serving as the incident light sensor, the reflected light irradiation position, and the incident light irradiation position. Thereby, not only the reflected light RL but also the position and the amount of the laser light L emitted from the fiber end 1 can be detected in real time, and it becomes possible to accurately grasp whether the light is incident on the fiber end 1.

[0042] Further, the control device 10 may further include a control unit 13 that adjusts the operating conditions of the laser processing device that processes the processing object W by irradiating the processing object W with the laser light L based on the amount of the fiber reflected light. In the first embodiment, the control unit 13 determines the operating conditions. However, the control device 10 may output the estimated value of the amount of the fiber reflected light and the state of the laser processing evaluated from the estimated value to assist the user's judgment and prompt the user to change the operating conditions. For example, the laser processing system 100 may be controlled based on the operating conditions input by the user of the control device 10 who has viewed the output information such as the estimated value of the amount of the fiber reflected light and the state of the laser processing evaluated from the estimated value.

[0043] Further, the control unit 13 may control the operating conditions based on a model showing the relationship between the processing conditions, the arrangement of the optical system of the laser processing apparatus, and the state quantity including the state of the workpiece W, the amount of light of the fiber reflected light, and the operating conditions, the state quantity acquired from the outside, and the amount of light of the fiber reflected light estimated by the reflection light estimation unit 12. By changing the operating conditions based on the processing conditions, it becomes possible to more accurately detect processing abnormalities. Note that the processing conditions include laser output, beam quality of the laser beam L, processing gas pressure, processing speed, irradiation position of the imaging optical system, imaging diameter of the imaging optical system of the laser beam L, pulse frequency of the laser beam L, duty ratio of the pulse of the laser beam L, magnification of the imaging optical system, nozzle diameter of the nozzle provided in the laser processing head 20, distance between the workpiece W and the nozzle, type of mode of the laser beam L, positional relationship between the center of the opening of the nozzle and the laser beam L, and the like. Further, the arrangement of the optical system is, for example, the positional relationship of the imaging optical system, the position of the condenser lens 4, and the like. The state of the workpiece W is, for example, the reflectivity of the workpiece W, the state of the surface of the workpiece W such as rust, the material of the workpiece W, and the like.

[0044] Note that the control unit 13 adjusts the operating conditions so that the amount of light of the fiber reflected light decreases. For example, as the adjustment content of the operating conditions for reducing the amount of light of the fiber reflected light, reducing the laser output, reducing the processing speed, turning off the power supply of the oscillator 8, physically blocking the emission of the laser beam L with the mechanical shutter provided in the oscillator 8, increasing the distance between the nozzle and the workpiece W, and the like can be mentioned. When the processing speed is reduced, the molten metal flows downward and penetrates, so that the amount of light of the reflected light RL can be reduced as a result. By increasing the distance between the nozzle and the workpiece W, the light incident on the laser processing head 20 among the reflected light RL reflected by the workpiece W can be reduced.

[0045] Further, according to Embodiment 1, a condensing lens 4 that condenses the laser light L incident from the fiber end 1 of the optical fiber 7 onto the workpiece W, an imaging lens 5-1 that is a reflected light imaging lens for imaging a part of the reflected light RL that is the laser light L reflected by the workpiece W, and a photodetector 6-1 that is a reflected light sensor for detecting the reflected light RL after passing through the imaging lens 5-1 that is the reflected light imaging lens are provided. The photodetector 6-1 that is the reflected light sensor detects the reflected light irradiation position that is the incident position of the reflected light RL on the photodetector 6-1 that is the reflected light sensor and the light amount of the reflected light RL. Thus, a laser processing head 20 can be provided.

[0046] The laser processing head 20 further includes an imaging lens 5-2 that is an incident light imaging lens for imaging a part of the laser light L incident from the fiber end 1 of the optical fiber 7, and a photodetector 6-2 that is an incident light sensor for detecting the laser light L after passing through the imaging lens 5-2 that is the incident light imaging lens. The photodetector 6-2 that is the incident light sensor may detect the incident light irradiation position that is the incident position of the laser light L on the photodetector 6-2 that is the incident light sensor and the light amount of the laser light L incident on the photodetector 6-2 that is the incident light sensor.

[0047] Further, according to Embodiment 1, a laser processing apparatus that laser-processes a workpiece W using the laser light L incident from the fiber end 1 of the optical fiber 7 includes a condensing lens 4 that condenses the laser light L onto the workpiece W, an imaging lens 5-1 that is a reflected light imaging lens for imaging a part of the reflected light RL that is the laser light L reflected by the workpiece W, a reflected light irradiation position that is the incident position of the reflected light RL after passing through the imaging lens 5-1 that is the reflected light imaging lens, a photodetector 6-1 that is a reflected light sensor for detecting the light amount of the reflected light RL, and a reflected light estimation unit 12 that estimates the light amount of the fiber reflected light that is another part of the reflected light RL and is incident on the fiber end 1 based on the reflected light irradiation position and the light amount of the reflected light RL incident on the photodetector 6-1 that is the reflected light sensor. Thus, a laser processing apparatus can be provided.

[0048] Moreover, according to Embodiment 1, there is provided a laser processing system 100 that performs laser processing on a workpiece W using laser light L incident from a fiber end 1 of an optical fiber 7, the laser processing system 100 including a condenser lens 4 that condenses the laser light L onto the workpiece W, an imaging lens 5-1 that is a reflected light imaging lens for imaging a part of the reflected light RL that is the laser light L reflected by the workpiece W, a reflected light irradiation position that is the incident position of the reflected light RL after passing through the imaging lens 5-1 that is the reflected light imaging lens, and a photodetector 6-1 that is a reflected light sensor for detecting the amount of the reflected light RL, and a reflected light estimation unit 12 that estimates the amount of the fiber reflected light that is another part of the reflected light RL and is incident on the fiber end 1 based on the reflected light irradiation position and the amount of the reflected light RL incident on the photodetector 6-1 that is the reflected light sensor.

[0049] The laser processing system 100 may further include an imaging lens 5-2 that is an incident light imaging lens for imaging a part of the laser light L incident from the fiber end 1 of the optical fiber 7, and a photodetector 6-2 that is an incident light sensor for detecting the laser light L after passing through the imaging lens 5-2 that is the incident light imaging lens. The photodetector 6-2 that is the incident light sensor detects the incident light irradiation position that is the incident position of the laser light L on the photodetector 6-2 that is the incident light sensor, and the amount of the laser light L incident on the photodetector 6-2 that is the incident light sensor, and the reflected light estimation unit 12 can estimate the amount of the fiber reflected light based on the incident light irradiation position and the amount of the laser light L incident on the photodetector 6-2 that is the incident light sensor.

[0050] The laser processing system 100 may further include a control unit 13 that adjusts the operating conditions of the laser processing system 100 based on the amount of the fiber reflected light.

[0051] Moreover, according to Embodiment 1, there is provided a laser processing method for laser-processing a workpiece W using laser light L incident from a fiber end 1 of an optical fiber 7, the method including: imaging a part of the reflected light RL, which is the laser light L reflected by the workpiece W, and causing the imaged light to enter a photodetector 6-1 serving as a reflected light sensor; detecting a reflected light irradiation position, which is the position where the reflected light RL enters the photodetector 6-1 serving as the reflected light sensor, and the amount of the reflected light RL entering the photodetector 6-1 serving as the reflected light sensor; and estimating the amount of the fiber reflected light, which is another part of the reflected light RL and enters the fiber end 1, based on the reflected light irradiation position and the amount of the reflected light RL entering the photodetector 6-1 serving as the reflected light sensor.

[0052] Embodiment 2. FIG. 7 is a diagram showing a functional configuration example of a control device 10A according to Embodiment 2. Although not shown, in Embodiment 2, the system configuration is the same as that in Embodiment 1, and a laser processing system 100A is a system including the control device 10A instead of the control device 10 in Embodiment 1.

[0053] The control device 10A includes a data acquisition unit 11, a reflected light estimation unit 12A, a control unit 13A, and a learned model storage unit 14. In Embodiment 2, when the reflected light estimation unit 12A estimates the amount of the fiber reflected light and when the control unit 13A determines the operation conditions based on the amount of the fiber reflected light, a learned model obtained by machine learning is used.

[0054] The learned model storage unit 14 stores a learned model for inferring the amount of light of the fiber reflected light and the operating conditions from the state quantity including the processing conditions, the arrangement of the optical system of the laser processing apparatus, and the state of the workpiece W, the reflected light irradiation position, and the amount of the reflected light RL incident on the photodetector 6-1. Here, although the learned model storage unit 14 is assumed to be built in the control device 10A, the learned model storage unit 14 may be provided in an external device of the control device 10A. Further, the learned model stored in the learned model storage unit 14 may be learned for the laser processing apparatus to be controlled by the control device 10A, or may be learned in another laser processing apparatus.

[0055] For example, the learned model may be for inferring the amount of light of the fiber reflected light and the operating conditions from the input data including the processing conditions during use, the reflected light irradiation position, and the amount of the reflected light RL incident on the photodetector 6-1. Here, it is assumed that the output of the learned model is the amount of light of the fiber reflected light and the operating conditions, but the output of the learned model may be only the amount of light of the fiber reflected light, or may be only the operating conditions. Here, the operating conditions output by the learned model may be the set value of the operating conditions, or may be the adjustment amount from the current value. Further, the output of the learned model may further include the possibility of failure of the oscillator 8, the possibility of damage to the optical components of the laser processing head 20, and the like.

[0056] Further, the input data of the learned model may include the incident light irradiation position which is the incident position of the laser light L incident on the photodetector 6-2, and the amount of the laser light L incident on the photodetector 6-2.

[0057] The learned model may be learned using learning data acquired from the laser processing system 100A that is the control target of the control device 10A, or may be learned using learning data acquired from another laser processing system. When using a learned model learned using learning data acquired from another laser processing system, it is desirable that the input data of the learned model include information regarding the configuration of the laser processing system 100A, such as the arrangement of the optical system included in the laser processing apparatus.

[0058] The learned model may be obtained, for example, by performing machine learning by so-called supervised learning according to a neural network model. Here, supervised learning refers to a method of giving a learning device a set of input and result data, learning a feature in the learning data, and inferring the result from the input.

[0059] A neural network is composed of an input layer consisting of a plurality of neurons, an intermediate layer consisting of a plurality of neurons, and an output layer consisting of a plurality of neurons. The intermediate layer may be one layer or two or more layers.

[0060] FIG. 8 is a diagram showing an example of a neural network used for machine learning in the second embodiment. FIG. 8 shows an example of a three-layer neural network. In the neural network shown in FIG. 8, when a plurality of inputs are input to the input layers X1-X3, the values are multiplied by weights V1 (v11-v16) and input to the intermediate layers Y1-Y2, and the result is further multiplied by weights V2 (v21-v26) and output from the output layers Z1-Z3. This output result changes depending on the values of the weights V1 and V2.

[0061] Here, the neural network learns the operating conditions by so-called supervised learning according to the learning data created based on the combination of the processing conditions, the reflected light irradiation position, the amount of the reflected light RL incident on the photodetector 6-1, and the operating conditions.

[0062] That is, the neural network learns by adjusting the weights V1 and V2 so that the result output from the output layer, with the processing conditions, the reflected light irradiation position, and the amount of the reflected light RL incident on the photodetector 6-1 input to the input layer, approaches the adjusted operating conditions.

[0063] Here, the case where supervised learning is applied to the learning algorithm has been described, but it is not limited to this. Regarding the learning algorithm, in addition to supervised learning, reinforcement learning, unsupervised learning, semi-supervised learning, etc. can also be applied. Also, as the learning algorithm, deep learning that learns the extraction of the feature amount itself can be used, and machine learning may be executed according to other known methods, for example, genetic programming, functional logic programming, support vector machines, etc.

[0064] The reflected light estimation unit 12A inputs input data to the learned model stored in the learned model storage unit 14, and acquires the amount of the fiber reflected light and the operating conditions obtained as the output. The reflected light estimation unit 12A sets the acquired amount of the fiber reflected light as the estimated value of the amount of the fiber reflected light. Also, the reflected light estimation unit 12A outputs the acquired operating conditions to the control unit 13A.

[0065] The control unit 13A controls the laser processing system 100A using the operating conditions obtained by inputting the input data to the learned model.

[0066] Note that in the above description, the learned model outputs the amount of fiber reflected light and the operating conditions from input data including the processing conditions during use, the reflected light irradiation position, and the amount of reflected light RL incident on the photodetector 6-1. However, if the same function can be realized, the configuration of the learned model is not limited to the above example. For example, as a modification, the control unit 13A may determine the operating conditions using a learned model that takes the amount of fiber reflected light estimated by the reflected light estimation unit 12 of the first embodiment as input data and infers the operating conditions. In this case, the amount of fiber reflected light used as input data may be obtained using a learned model like the reflected light estimation unit 12A. In this case, the learned model storage unit 14 stores a first learned model for inferring the amount of fiber reflected light from the processing conditions during use, the reflected light irradiation position, and the amount of reflected light RL incident on the photodetector 6-1, and a second learned model for inferring the operating conditions from the amount of fiber reflected light.

[0067] As described above, according to the second embodiment, in addition to the functions of the first embodiment, a control device 10A using machine learning can be provided. The reflected light estimation unit 12A of the control device 10A inputs the processing conditions, the reflected light irradiation position, and the amount of reflected light RL incident on the photodetector 6-1, which is a reflected light sensor, into a learned model for inferring the amount of fiber reflected light from input data including these, and can use the amount of fiber reflected light obtained thereby as an estimated value of the amount of fiber reflected light.

[0068] Further, the control device 10A may include a control unit 13A that controls a laser processing device that processes the workpiece W by irradiating the workpiece W with the laser beam L, using the operating conditions obtained by inputting the processing conditions during use, the reflection light irradiation position, and the amount of the reflection light RL incident on the photodetector 6-1 which is a reflection light sensor, into a learned model for inferring the operating conditions of the laser processing device that processes the workpiece W by irradiating the workpiece W with the laser beam L from the input data including the above items.

[0069] Further, the input data of the learned model used by the control device 10A may further include the incident light irradiation position which is the incident position where a part of the laser beam L is incident on the photodetector 6-2 which is an incident light sensor, and the amount of the laser beam L incident on the photodetector 6-2 which is an incident light sensor. Thereby, even when the irradiation position of the laser beam L changes over time, it becomes possible to perform inference according to the state acquired in real time. Also, when using a learned model learned using learning data acquired by a device other than the laser processing device to be controlled by the control device 10A, even if there are individual differences in the incident position of the laser beam L for each laser processing device, accurate inference can be performed.

[0070] The input data of the learned model may further include the arrangement of the optical system of the laser processing device that processes the workpiece W by irradiating the workpiece W with the laser beam L.

[0071] Further, the control device 10A may include a control unit 13A that controls a laser processing device that processes the workpiece W by irradiating the workpiece W with the laser beam L, using the operating conditions obtained by inputting the amount of the fiber reflection light estimated by the reflection light estimation unit 12, into a learned model for inferring the operating conditions of the laser processing device from the amount of the fiber reflection light.

[0072] Further, according to the second embodiment, the operating conditions are inferred from the input data including the processing conditions, the reflected light irradiation position, and the amount of the reflected light RL incident on the photodetector 6-1 which is a reflected light sensor, and the operating conditions obtained by inputting the processing conditions during use, the reflected light irradiation position, and the amount of the reflected light RL acquired from the photodetector 6-1 which is a reflected light sensor into the learned model for inferring the operating conditions are used to control the laser processing system 100A, and thus the laser processing system 100A including the control unit 13A can be provided.

[0073] Embodiment 3. FIG. 9 is a diagram showing a configuration example of the laser processing system 100B according to the third embodiment. The laser processing system 100B has a laser processing head 20B instead of the laser processing head 20 of the laser processing system 100 according to the first embodiment. Since the other configurations are the same as those in the first embodiment, detailed descriptions thereof are omitted here.

[0074] The laser processing head 20B has a reflected light removing optical element 9 on the optical path between the fiber end 1 of the laser processing head 20 according to the first embodiment and the object W to be processed, more specifically, on the optical path between the fiber end 1 and the collimating lens 2. The reflected light removing optical element 9 is a refractive optical element in which the magnitude of the change in the angle between the incident light and the emitted light is different depending on whether the incident position on the reflected light removing optical element 9 is the central portion or the outer edge portion. The reflected light removing optical element 9 has a first surface close to the fiber end 1 and a second surface that is the back surface of the first surface, and is arranged such that the laser light L emitted from the fiber end 1 and incident on the first surface enters the central portion. Further, the reflected light removing optical element 9 refracts the light incident on the outer edge portion of the second surface to the outside of the outer shape of the fiber end 1. Thereby, it becomes possible to reduce the reflected light RL incident on the fiber end 1. Regarding the reflected light RL incident on the central portion of the reflected light removing optical element 9, there remains a possibility of entering the fiber end 1, but as described in the first embodiment, the control device 10 can reduce the fiber reflected light by adjusting the operating conditions. The function of the control device 10 is the same as that of the first embodiment except that the correspondence relationship between the reflected light irradiation position detected by the photodetector 6-1 and the incident position of the reflected light RL on the yz plane at the position of the fiber end 1 is different due to the presence of the reflected light removing optical element 9.

[0075] Also, in FIG. 9, the laser processing system 100B is shown having the control device 10, but it may have the control device 10A according to the second embodiment instead of the control device 10.

[0076] As described above, according to the third embodiment, in addition to the configuration of the laser processing head 20 of the first embodiment, on the optical path between the fiber end 1 and the object W to be processed, more specifically, on the optical path between the fiber end 1 and the collimating lens 2, there is provided a reflected light removing optical element 9 which is a refractive optical element in which the magnitude of the change in the angle between the incident light and the emitted light is different depending on whether the incident position is the central portion or the outer edge portion.

[0077] The reflection light removing optical element 9 has a first surface close to the fiber end 1 and a second surface which is the back surface of the first surface, and is arranged such that the laser light L emitted from the fiber end 1 and incident on the first surface enters the central portion, and has the property of refracting the light incident on the outer edge portion of the second surface to the outside of the outer shape of the fiber end 1. Thereby, it is possible to further reduce the reflection light RL incident on the fiber end 1. Since the reflection light removing optical element 9 only needs to be able to give a change in the angle between the incident light and the emitted light, it may be installed between the collimating lens 2 and the bending mirror 3, or may be installed between the bending mirror 3 and the condensing lens 4. Further, in the above, an example of installing one reflection light removing optical element 9 is shown, but a plurality of reflection light removing optical elements 9 may be arranged.

[0078] Next, the hardware configuration of the control devices 10, 10A will be described. The control devices 10, 10A are realized by, for example, a computer system. The control devices 10, 10A may be realized by one computer system, or may be realized by a plurality of computer systems. For example, the control devices 10, 10A may be realized using a cloud system. In a cloud system, the separation between the hardware of the computer system and devices such as servers for each function can be arbitrarily set. For example, one computer system may have the functions of a plurality of devices, or a plurality of computer systems may have the function of one device.

[0079] A configuration example of the computer system that realizes the control devices 10, 10A will be described. FIG. 10 is a diagram showing a configuration example of the computer system that realizes the control devices 10, 10A of Embodiments 1 to 3. As shown in FIG. 10, this computer system includes a control unit 101, an input unit 102, a storage unit 103, a display unit 104, a communication unit 105, and an output unit 106, which are connected via a system bus 107.

[0080] In FIG. 10, the control unit 101 is, for example, a CPU (Central Processing Unit) or the like. The control unit 101 executes a control program in which each process performed by the control devices 10 and 10A in Embodiments 1 to 3 is described. The input unit 102 is composed of, for example, a keyboard, a mouse, etc., and is used by a user of the computer system to input various information. The storage unit 103 includes various memories such as a RAM (Random Access Memory) and a ROM (Read Only Memory), and storage devices such as a hard disk, and stores the program to be executed by the control unit 101, necessary data obtained during the process of the process, and the like. Further, the storage unit 103 is also used as a temporary storage area for the program. The display unit 104 is composed of, for example, an LCD (Liquid Crystal Display), and displays various screens for the user of the computer system. The communication unit 105 is a communication circuit or the like that performs communication processing. The communication unit 105 may be composed of a plurality of communication circuits respectively corresponding to a plurality of communication methods. The output unit 106 is an output interface that outputs data to an external device such as a printer or an external storage device.

[0081] Note that FIG. 10 is an example, and the configuration of the computer system is not limited to the example of FIG. 10. For example, the computer system may not include the output unit 106. Further, when the functions of the control devices 10 and 10A are realized by a plurality of computer systems, not all of these computer systems need to be the computer system shown in FIG. 10. For example, some of the computer systems may not include at least one of the display unit 104, the output unit 106, and the input unit 102 shown in FIG. 10.

[0082] Here, an operation example of the computer system until the control program describing the processing of the control devices 10 and 10A becomes executable will be described. In the computer system having the above-described configuration, for example, the control program is installed in the storage unit 103 from a CD-ROM or a DVD-ROM set in a CD (Compact Disc)-ROM drive or a DVD (Digital Versatile Disc)-ROM drive (not shown). Then, when the control program is executed, the control program read from the storage unit 103 is stored in the area that becomes the main storage device of the storage unit 103. In this state, the control unit 101 executes the processing as the control devices 10 and 10A in the first to third embodiments according to the control program stored in the storage unit 103.

[0083] In the above description, a program describing the processing in the control devices 10 and 10A is provided using a CD-ROM or a DVD-ROM as a recording medium. However, the present invention is not limited to this, and depending on the configuration of the computer system, the capacity of the provided program, etc., for example, a program provided by a transmission medium such as the Internet via the communication unit 105 may be used.

[0084] The control program causes the computer to execute steps of obtaining a reflection light irradiation position, which is an incident position where a part of the reflected light RL obtained by reflecting the laser light L incident from the fiber end 1 of the optical fiber 7 on the processing object W enters the photodetector 6-1, which is a reflected light sensor, and the light amount of the reflected light RL entering the photodetector 6-1, which is a reflected light sensor, and estimating the light amount of the fiber reflected light, which is another part of the reflected light RL and is the reflected light RL entering the fiber end 1, based on the reflection light irradiation position and the light amount of the reflected light RL entering the photodetector 6-1, which is a reflected light sensor.

[0085] For example, the data acquisition unit 11 shown in FIGS. 4 and 7 is realized by the control unit 101, the input unit 102, and the storage unit 103 shown in FIG. 10. The reflected light estimation units 12 and 12A shown in FIGS. 4 and 7 are realized by the control unit 101 and the display unit 104. The control units 13 and 13A shown in FIGS. 4 and 7 are realized by the control unit 101 shown in FIG. 10. The learned model storage unit 14 shown in FIG. 7 is realized by the storage unit 103 shown in FIG. 10.

[0086] Note that the division of functions in each device shown in FIGS. 4 and 7 is an example. As long as the laser processing systems 100, 100A, and 100B can perform the above-described operations, the division of functions in each device is not limited to the examples shown in FIGS. 4 and 7. For example, in the above, the control devices 10 and 10A and the laser processing heads 20 and 20B are combined as a laser processing device. However, the control devices 10 and 10A may be separate devices from the laser processing device, or may not have all the functions of the control devices 10 and 10A in the laser processing device.

[0087] Also, the functions of the control devices 10 and 10A may be realized by dedicated hardware. For example, the functions of the control devices 10 and 10A are realized by the processing circuit 90 shown in FIG. 11. FIG. 11 is a diagram showing dedicated hardware for realizing the functions of the control devices 10 and 10A in Embodiments 1 to 3. The processing circuit 90 is a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof.

[0088] Also, part of the functions of the control devices 10 and 10A may be realized using the dedicated hardware shown in FIG. 11, and the other part may be realized using the computer system shown in FIG. 10.

[0089] The configurations shown in the above embodiments are merely examples, and it is possible to combine them with other known technologies, combine the embodiments with each other, or omit or modify a part of the configuration without departing from the gist.

Explanation of Reference Numerals

[0090] 1 fiber end, 2 collimating lens, 3 bending mirror, 4 condensing lens, 5-1, 5-2 imaging lens, 6-1, 6-2 photodetector, 7 optical fiber, 8 oscillator, 9 reflected light removal optical element, 10, 10A control device, 11 data acquisition unit, 12, 12A reflected light estimation unit, 13, 13A control unit, 14 learned model storage unit, 20, 20B laser processing head, 41 imaging optical system position change drive unit, 100, 100A, 100B laser processing system, 101 control unit, 102 input unit, 103 storage unit, 104 display unit, 105 communication unit, 106 output unit, 107 system bus, L laser light, RL reflected light, W object to be processed.

Claims

1. A data acquisition unit acquires the reflected light irradiation position, which is the incident position where a portion of the reflected light, which is the laser light incident from the fiber end of an optical fiber, is reflected by the workpiece, and the amount of light of the reflected light incident on the reflected light sensor, A reflected light estimation unit estimates the amount of fiber reflected light, which is another part of the reflected light that is incident on the fiber end, based on the reflected light irradiation position and the amount of reflected light incident on the reflected light sensor. Equipped with A control device characterized by the following features.

2. The data acquisition unit acquires the incident light irradiation position, which is the incident position where a portion of the laser light enters the incident light sensor, and the amount of light of the laser light that entered the incident light sensor. The reflected light estimation unit estimates the amount of light of the fiber reflected light based on the amount of light of the reflected light incident on the reflected light sensor, the amount of light of the laser light incident on the incident light sensor, the reflected light irradiation position, and the incident light irradiation position. The control device according to feature 1.

3. A control unit adjusts the operating conditions of a laser processing apparatus that processes an object by irradiating it with the laser light, based on the amount of light reflected from the fiber. To further enhance The control device according to claim 1 or 2.

4. The control unit controls the operating conditions based on a model showing the relationship between state quantities including processing conditions, the arrangement of the optical system of the laser processing apparatus, and the state of the workpiece, the amount of fiber reflected light, and the operating conditions, the state quantities acquired from an external source, and the amount of fiber reflected light estimated by the reflected light estimation unit. The control device according to claim 3.

5. The control unit adjusts the operating conditions so that the amount of light reflected from the fiber decreases. The control device according to claim 3.

6. The reflected light estimation unit uses input data, including processing conditions, the reflected light irradiation position, and the amount of reflected light incident on the reflected light sensor, to estimate the amount of fiber reflected light. This amount of fiber reflected light is obtained by inputting the processing conditions currently in use, the reflected light irradiation position, and the amount of reflected light obtained from the reflected light sensor into a trained model for inferring the amount of fiber reflected light, and is used as the estimated value of the amount of fiber reflected light. The control device according to claim 3.

7. The reflected light estimation unit uses the processing conditions, the reflected light irradiation position, and the amount of reflected light incident on the reflected light sensor as input to a trained model for inferring the amount of light of the fiber reflected light. The amount of light of the fiber reflected light obtained by inputting the processing conditions in use, the reflected light irradiation position, and the amount of reflected light acquired from the reflected light sensor is used as the estimated value of the amount of light of the fiber reflected light. The control device according to feature 1.

8. A control unit controls a laser processing apparatus that processes a workpiece by irradiating it with the aforementioned laser light, using operating conditions obtained by inputting the processing conditions currently in use, the reflected light irradiation position, and the amount of reflected light incident on the reflected light sensor into a trained model for inferring the operating conditions of the laser processing apparatus that processes a workpiece by irradiating it with the aforementioned laser light, from input data including processing conditions, the reflected light irradiation position, and the amount of reflected light incident on the reflected light sensor, To further enhance The control device according to feature 1.

9. The input data of the trained model further includes the incident light irradiation position, which is the incident position where a portion of the laser light enters the incident light sensor, and the amount of light of the laser light that entered the incident light sensor. The control device according to feature 7 or 8.

10. The input data of the trained model further includes the arrangement of the optical system of a laser processing apparatus that processes an object by irradiating the object with the laser light. The control device according to feature 7 or 8.

11. A control unit controls a laser processing apparatus that processes an object by irradiating it with the aforementioned laser light, using operating conditions obtained by inputting the amount of light of the fiber reflected light estimated by the reflected light estimation unit into a trained model for inferring the operating conditions of the laser processing apparatus from the amount of light of the fiber reflected light. To further enhance The control device according to feature 1.

12. A focusing lens that concentrates laser light entering from the end of an optical fiber onto the workpiece, A reflected light imaging lens that images a portion of the reflected light, which is the laser light reflected from the workpiece, A reflected light sensor that detects the reflected light after it has passed through the reflected light imaging lens, Equipped with, The reflected light sensor detects the reflected light irradiation position, which is the position where the reflected light enters the reflected light sensor, and the amount of reflected light. A laser processing head characterized by the following features.

13. An incident light imaging lens that images a portion of the laser light incident from the fiber end of the optical fiber, An incident light sensor that detects the laser light after it has passed through the incident light imaging lens, Furthermore, The incident light sensor detects the incident light irradiation position, which is the position where the laser light enters the incident light sensor, and the amount of light from the laser light entering the incident light sensor. The laser processing head according to feature 12.

14. A reflecting light rejection optical element is a refractive optical element in the optical path between the fiber end and the workpiece, wherein the magnitude of the change in angle between the incident light and the outgoing light differs depending on whether the incident position is at the center or at the outer edge. To further enhance A laser processing head as described in 12 or 13, characterized by its features.

15. The reflected light removal optical element has a first surface near the fiber end and a second surface which is the back surface of the first surface. The laser light emitted from the fiber end and incident on the first surface is positioned to be incident on the central part, and the light incident on the outer edge of the second surface is refracted outward beyond the outer shape of the fiber end. The laser processing head according to feature 14.

16. A laser processing apparatus that uses laser light incident from the fiber end of an optical fiber to laser process an object to be processed, A focusing lens for focusing the laser beam onto the workpiece, A reflected light imaging lens that images a portion of the reflected light, which is the laser light reflected from the workpiece, A reflected light sensor detects the reflected light irradiation position, which is the incident position of the reflected light after it has passed through the reflected light imaging lens, and the amount of reflected light. A reflected light estimation unit estimates the amount of fiber reflected light, which is another part of the reflected light that is incident on the fiber end, based on the reflected light irradiation position and the amount of reflected light incident on the reflected light sensor. Equipped with A laser processing apparatus characterized by the following features.

17. A laser processing system that uses laser light incident from the end of an optical fiber to laser process an object to be processed, A focusing lens for focusing the laser beam onto the workpiece, A reflected light imaging lens that images a portion of the reflected light, which is the laser light reflected from the workpiece, A reflected light sensor detects the reflected light irradiation position, which is the incident position of the reflected light after it has passed through the reflected light imaging lens, and the amount of reflected light. A reflected light estimation unit estimates the amount of fiber reflected light, which is another part of the reflected light that is incident on the fiber end, based on the reflected light irradiation position and the amount of reflected light incident on the reflected light sensor. Equipped with A laser processing system characterized by the following features.

18. An incident light imaging lens that images a portion of the laser light incident from the fiber end of the optical fiber, An incident light sensor that detects the laser light after it has passed through the incident light imaging lens, Furthermore, The incident light sensor detects the incident light irradiation position, which is the position where the laser light enters the incident light sensor, and the amount of light from the laser light entering the incident light sensor. The reflected light estimation unit estimates the amount of fiber reflected light based on the incident light irradiation position and the amount of laser light incident on the incident light sensor. The laser processing system according to feature 17.

19. A control unit that adjusts the operating conditions of the laser processing system based on the amount of light reflected from the fiber, To further enhance The laser processing system according to feature 17 or 18.

20. The control unit controls the laser processing system using operating conditions obtained by inputting the processing conditions currently in use, the reflected light irradiation position, and the amount of reflected light incident on the reflected light sensor into a trained model for inferring the operating conditions from input data including processing conditions, the reflected light irradiation position, and the amount of reflected light incident on the reflected light sensor. The laser processing system according to feature 19.

21. A laser processing method that uses laser light incident from the end of an optical fiber to laser process an object to be processed, The steps include: forming an image of a portion of the reflected light, which is the laser light reflected from the workpiece, and directing it into a reflected light sensor; The steps include detecting the reflected light irradiation position, which is the position where the reflected light is incident on the reflected light sensor, and the amount of reflected light incident on the reflected light sensor, A step of estimating the amount of fiber reflected light, which is another part of the reflected light that is incident on the fiber end, based on the reflected light irradiation position and the amount of reflected light incident on the reflected light sensor, A laser processing method characterized by including [a certain component].

Images