JP7489664B2 - Laser processing apparatus and optical adjustment method for laser processing apparatus - Google Patents

Description

This disclosure relates to a laser processing device and an optical adjustment method for the laser processing device.

Patent Document 1 discloses a method for accurately measuring the penetration depth of laser light in a workpiece using measurement light. This measurement is performed by aligning the irradiation position of the laser light on the workpiece with the irradiation position of the measurement light. A laser processing device to which this method is applied is equipped with optical components such as mirrors and lenses that guide the emitted laser light and measurement light to the workpiece.

JP 2016-538134 A

In the above-mentioned laser processing device, because the output of the laser light is relatively high, the member that fixes the optical member undergoes thermal deformation during processing with the laser light. Under such conditions, if the irradiation position of the laser light and the irradiation position of the measurement light on the workpiece are changed, the irradiation position of the laser light and the irradiation position of the measurement light on the workpiece will shift. As a result, the irradiation position of the laser light cannot be measured with high accuracy.

The present disclosure aims to solve the above-mentioned problems by providing a laser processing device that achieves high-precision alignment between the irradiation position of the laser light and the irradiation position of the measurement light on the workpiece.

In order to achieve the above object, the laser processing apparatus of the present disclosure includes a laser light emitting unit that emits laser light for processing a workpiece, a measurement light emitting unit that emits measurement light for measuring the irradiation position of the laser light on the workpiece, a relative position derivation unit that derives the relative position of the optical axis of the measurement light with respect to the optical axis of the laser light, an optical path changing unit that changes the optical path of at least one of the laser light and the measurement light based on the relative position derived by the relative position derivation unit , and a measurement unit that measures the depth of a processing point, wherein the optical path changing unit changes the optical path of at least one of the laser light and the measurement light so as to align the irradiation position of the laser light on the workpiece with the irradiation position of the measurement light based on the depth of the processing point measured by the measurement unit, and changes the optical path of at least one of the laser light and the measurement light based on the relative position derived by the relative position derivation unit when the irradiation position of the laser light on the workpiece with the irradiation position of the measurement light on the workpiece are aligned .

Further, in order to achieve the above-mentioned object, the optical adjustment method of a laser processing apparatus disclosed herein is an optical adjustment method of a laser processing apparatus including a laser light emitting unit that emits laser light to a workpiece , a measurement light emitting unit that emits measurement light for measuring the irradiation position of the laser light on the workpiece, and a measurement unit that measures the depth of a processing point , and based on the depth of the processing point measured by the measurement unit, changes an optical path of at least one of the laser light and the measurement light so as to align the irradiation position of the laser light on the workpiece with the irradiation position of the measurement light, and when the irradiation position of the measurement light is aligned, a relative position derivation step is performed to derive the relative position of the optical axis of the measurement light with respect to the optical axis of the laser light, and changes the optical path of at least one of the laser light and the measurement light based on the relative position derived by the relative position derivation step and the relative position derived after the relative position derivation step.

According to the present disclosure, it is possible to achieve highly accurate alignment between the irradiation position of the laser light and the irradiation position of the measurement light on the workpiece.

FIG. 1 is a schematic diagram showing a laser processing apparatus according to an embodiment of the present disclosure. FIG. 13 is a diagram showing a state when the relative position deriving unit derives the relative position of the optical axis of the measurement light with respect to the optical axis of the processing light. Flowchart of a program executed by the control device FIG. 13 is a diagram showing the irradiation position of the processing light and the irradiation position of the measurement light on the image sensor in the first optical adjustment. FIG. 13 is a diagram showing the irradiation positions of the processing light and the measurement light on the image sensor in the second and subsequent optical adjustments; FIG. 13 is a diagram showing a state in which second or subsequent optical adjustments are being performed in a laser processing apparatus according to a modified example of an embodiment of the present disclosure; FIG. 13 is a diagram showing a state in which the first or subsequent optical adjustment is being performed in the laser processing apparatus according to the modified example of the embodiment of the present disclosure;

The laser processing device 1 according to the embodiment of the present disclosure will be described below with reference to the drawings. Note that the upper and lower sides in FIG. 1 are respectively above and below the laser processing device 1, the left and right sides are respectively the left and right sides of the laser processing device 1, and the front and back sides of the paper are respectively the front and rear of the laser processing device 1.

The laser processing device 1 includes a processing head 2, a measurement unit 3, a measurement processing unit 4, and a laser oscillator 5. The measurement unit 3 is an example of a "measurement light emitting unit." The measurement processing unit 4 is an example of a "measurement unit." The laser oscillator 5 is an example of a "laser light emitting unit."

Processing head 2 receives processing light LB, which is a laser beam for processing workpiece W. Processing head 2 irradiates the input processing light LB onto workpiece W, which is positioned below processing head 2. In addition, processing head 2 receives measurement light MB for measuring the irradiation position of processing light LB on workpiece W. Processing head 2 irradiates workpiece W with the input measurement light MB.

The measurement unit 3 is, for example, an optical interferometer for OCT (Optical Coherence Tomography) measurement. The measurement unit 3 emits laser light for OCT measurement as measurement light MB. The wavelength of the measurement light MB is, for example, 1300 nm. The emitted measurement light MB is input to the processing head 2 from the measurement light introduction port 6 and travels downward.

The laser oscillator 5 oscillates processing light LB. The oscillated processing light LB is input to the processing head 2 from the processing light inlet 7 located to the left of the measurement light inlet 6, and travels downward. The processing light LB is, for example, a YAG laser or a fiber laser. The wavelength of the processing light LB is different from the wavelength of the measurement light MB, and is, for example, 1064 nm. A first mirror 8 and a first lens 9 are arranged below the processing light inlet 7 within the processing head 2. The first lens 9 is an example of a "lens".

The processing light LB input from the processing light inlet 7 passes through the first mirror 8. The first mirror 8 is a dichroic mirror. The first mirror 8 has the property of transmitting light with the wavelength of the processing light LB and reflecting light with the wavelength of the measurement light MB.

The processing light LB is then converged by the first lens 9 and collected at the processing point WP on the processing surface S of the workpiece W. This causes the processing point WP to be laser processed. At this time, the workpiece W melts at the processing point WP, forming a molten pool M. In addition, the molten metal evaporates in the molten pool M, and a keyhole H is formed by the pressure of the vapor generated by the evaporation.

The measurement light MB input from the measurement light inlet 6 is converted into parallel light by the collimating lens 10 arranged below the measurement light inlet 6. The measurement light MB is then reflected by the second mirror 11 arranged below the collimating lens 10 toward the first mirror 8 arranged on the optical path of the processing light LB. The measurement light MB is then reflected by the first mirror 8 toward the processing point WP. The first mirror 8 and the second mirror 11 correspond to "mirrors".

An angle adjustment mechanism (not shown) is also provided on the second mirror 11. The angle adjustment mechanism changes the angle of the second mirror 11. When the angle adjustment mechanism changes the angle of the second mirror 11, the second mirror 11 changes the optical path of the measurement light MB. The second mirror 11 is an example of an "optical path changing section."

The measurement light MB is then converged by the first lens 9 and travels toward the processing point WP. As described below, the angle of the second mirror 11 is adjusted so that the measurement light MB is irradiated onto the lowest point of the keyhole H formed at the processing point WP.

The measurement light MB is then reflected at the lowest point of the keyhole H, and travels back along the optical path of the measurement light MB to reach the measurement unit 3. The measurement unit 3 generates an optical interference intensity signal based on the interference caused by the difference between the optical path length of the reflected measurement light MB and the optical path length of the emitted measurement light MB.

The measurement processing unit 4 measures the depth of the keyhole H, i.e., the penetration depth of the processing point WP, based on the optical interference intensity signal generated by the measurement unit 3. The penetration depth is the distance between the lowest point of the keyhole H and the processing surface S.

The laser processing device 1 further includes a relative position derivation unit 20 and a control device 30.

The relative position derivation unit 20 derives the relative position of the optical axis of the measurement light MB with respect to the optical axis of the processing light LB. The relative position derivation unit 20 is disposed between the first mirror 8 and the first lens 9. The relative position derivation unit 20 includes a reflecting unit 21, a beam terminator 22, a second lens 23, and a light receiving unit 24.

The reflector 21 and the beam terminator 22 are configured to be movable between a first position P1 (FIG. 1) that is off the optical path of the processing light LB and the measurement light MB, and a second position P2 (FIG. 2) that is on the optical path of the processing light LB and the measurement light MB. The second lens 23 and the light receiving unit 24 are disposed to the left of the reflector 21.

When the reflecting unit 21 is located at the second position P2, it is a mirror that reflects the processing light LB and the measurement light MB toward the second lens 23. The reflecting unit 21 also has the property of separating the light of the wavelength of the processing light LB into reflected light and transmitted light, and totally reflecting the light of the wavelength of the measurement light MB. The reflectance of the processing light LB of the reflecting unit 21 is set to a predetermined value. The predetermined value is a value that causes the intensity of the reflected light of the processing light LB irradiated to the light receiving unit 24 to be within a predetermined range. The predetermined range is a range whose lower limit is smaller than the intensity of the measurement light MB and whose upper limit is larger than the intensity of the measurement light MB, and is a range of intensity that can be received by the light receiving unit 24.

For example, if a fiber laser with a rated output of 1 kW or more is selected for the processing light LB, the minimum output of the processing light LB is about 100 W. On the other hand, when an OCT light source is used as the measurement light MB, the output of the measurement light MB is about several tens of mW. Therefore, in order to reduce the 100 W processing light LB to an output of the same order as the several tens of mW measurement light MB (several tens of mW), it is desirable to set the reflectance of the reflecting portion 21 for the processing light LB to 0.1% or less. Note that since there is no need to attenuate the measurement light MB, it is desirable to set the reflectance of the reflecting portion 21 for the measurement light MB to 90% or more.

In addition, when the processing light LB is irradiated to the light receiving unit 24, it is desirable to set the output of the processing light LB to an output of 10% or more of the rated output of the laser oscillator 5. This is because, particularly when the laser oscillator 5 is a fiber laser, if the output of the processing light LB is less than 10% of the rated output, the oscillation state of the processing light LB becomes unstable, and the accuracy of the irradiation position LP of the processing light LB on the light receiving unit 24 decreases.

The beam terminator 22 receives the transmitted light that has passed through the reflector 21 at the second position P2 and terminates the transmitted light.

The second lens 23 converges the reflected light and the measurement light MB. The converged reflected light and the measurement light MB proceed toward the light receiving unit 24.

The light receiving unit 24 receives the reflected light and the measurement light MB. The light receiving unit 24 is a two-dimensional imaging element that is sensitive to the wavelengths of the processing light LB and the measurement light MB. The light receiving unit 24 is, for example, a commercially available industrial camera having elements such as a CCD (Charge-Coupled Device), a CMOS (Complementary Metal Oxide Semiconductor), or InGaAs (Indium Gallium Arsenide), or a two-dimensional beam profiler.

The shape of the second lens 23 and the distance between the light receiving unit 24 and the second lens 23 are set so that the focal point of the converged reflected light and measurement light MB is located on the light receiving surface that receives the reflected light and measurement light MB in the light receiving unit 24.

The control device 30 is a computer that provides overall control of the laser processing device 1. The control device 30 controls the angle adjustment mechanism to adjust the angle of the second mirror 11.

Next, the operation of the laser processing device 1 and the program executed by the control device 30 will be described with reference to the flowchart in FIG. 3. This program performs optical adjustment to align the irradiation position of the processing light LB and the irradiation position of the measurement light MB on the workpiece W. The description will start from the state in which the reflector 21 and the beam terminator 22 are located at the first position P1 (FIG. 1).

In S100, the control device 30 determines whether the current optical adjustment is the first optical adjustment. If the relative position R, which is the irradiation position MP of the measurement light MB relative to the irradiation position LP of the processing light LB on the light receiving unit 24 described later, is not stored in the control device 30, the current optical adjustment is the first optical adjustment. In this case (YES in S100), the control device 30 aligns the irradiation position of the processing light LB on the workpiece W with the irradiation position of the measurement light MB in S102.

Specifically, the control device 30 irradiates the processing light LB onto the processing surface of the workpiece (not shown) for adjustment, which is prepared for optical adjustment, to form a microhole. Next, the control device 30 scans the microhole with the measurement light MB while adjusting the angle of the second mirror 11 to change the optical path of the measurement light MB, and derives the lowest point of the microhole, i.e., the position where the optical path length of the measurement light MB is the longest, from the measurement result of the measurement processing unit 4. The lowest point of the microhole corresponds to the irradiation position of the processing light LB. The control device 30 adjusts the angle of the second mirror 11 to match the irradiation position of the measurement light MB to the lowest point of the microhole, thereby matching the irradiation position of the processing light LB on the workpiece for adjustment with the irradiation position of the measurement light MB. As a result, the irradiation position of the processing light LB on the actual workpiece W matches the irradiation position of the measurement light MB.

Then, in S104, the control device 30 moves the reflector 21 and the beam terminator 22 to the second position P2 (FIG. 2). The transmitted light of the processing light LB is terminated by the beam terminator 22. Meanwhile, the reflected light of the processing light LB and the measurement light MB are reflected by the reflector 21, converged by the second lens 23, and irradiated to the light receiving unit 24.

At this time, even though the irradiation position of the processing light LB and the irradiation position of the measurement light MB on the workpiece W are aligned, the irradiation position LP of the reflected light on the light receiving unit 24 does not match the irradiation position MP of the measurement light MB (Figure 4). This is because, even if the irradiation position of the processing light LB and the irradiation position of the measurement light MB on the workpiece W are aligned, the processing light LB and the measurement light MB have different wavelengths as described above, and therefore the optical axis of the processing light LB and the optical axis of the measurement light MB do not match due to the influence of chromatic aberration of the first lens 9. Furthermore, the reflected light, which is the processing light LB irradiated to the light receiving unit 24, and the measurement light MB are converged by the second lens 23, which has a different chromatic aberration from the first lens 9. For these reasons, the irradiation position LP of the reflected light on the light receiving unit 24 does not match the irradiation position MP of the measurement light MB.

However, the relative position R, which is the irradiation position MP of the measurement light MB relative to the irradiation position LP of the reflected light of the processing light LB in the light receiving unit 24 at this time (i.e., the deviation between the irradiation position LP of the reflected light and the irradiation position MP of the measurement light MB), is the relative position R in the light receiving unit 24 when the irradiation position of the processing light LB on the workpiece W and the irradiation position of the measurement light MB are aligned.

The relative position R is measured by the light receiving unit 24. Note that the relative position R in the light receiving unit 24 correlates with the relative position of the optical axis of the measurement light MB with respect to the optical axis of the processing light LB. In other words, the light receiving unit 24 indirectly derives the relative position of the optical axis of the measurement light MB with respect to the optical axis of the processing light LB. The measurement result of the light receiving unit 24 is output to the control device 30.

In S106, the control device 30 derives and stores the relative position R, which is the irradiation position MP of the measurement light MB relative to the irradiation position LP of the reflected light at the light receiving unit 24 at this time, from the measurement result of the light receiving unit 24 as the relative position R at the light receiving unit 24 when the irradiation position of the processing light LB on the workpiece W and the irradiation position of the measurement light MB are aligned.

Then, in S108, the control device 30 moves the reflector 21 and the beam terminator 22 to the first position P1 and ends the program. After this, the workpiece W is processed. The control device 30 executes the program at a predetermined timing (for example, every predetermined time (10 seconds)) in order to perform optical adjustments during processing.

When the control device 30 restarts the program, it determines in S100 whether the current optical adjustment is the first optical adjustment. If the above-mentioned relative position R is stored in the control device 30, the current optical adjustment is the second or subsequent optical adjustment. In this case (NO in S100), the control device 30 moves the reflector 21 and the beam terminator 22 to the second position P2 (Figure 2) in S110. As a result, as described above, the processing light LB and the measurement light MB are reflected by the reflector 21, converged by the second lens 23, and irradiated to the light receiving unit 24.

At this time, the irradiation position LP of the reflected light of the processing light LB on the light receiving unit 24 and the irradiation position MP of the measurement light MB (the irradiation position MP of the measurement light MB before adjustment) have shifted since the first optical adjustment (Figure 5). In other words, the relative position R on the light receiving unit 24 is different from the relative position R derived by the control device 30.

This is because the processing light LB has a relatively high output, and as a result, the temperature of the components of the processing head 2 and the fixing members that fix the components rise, causing thermal deformation of the fixing members and thus displacement of the components, which changes the optical path of the processing light LB and the optical path of the measurement light MB. Note that at this time, when the reflector 21 and the beam terminator 22 are located at the first position P1, the angles of incidence of the processing light LB and the measurement light MB to the first lens 9, and therefore the irradiation positions of the processing light LB and the measurement light MB on the workpiece W, also change.

Next, in S112, the control device 30 adjusts the relative position R in the light receiving unit 24 based on the derived relative position R. Specifically, the control device 30 adjusts the angle of the second mirror 11 to change the optical path of the measurement light MB, thereby displacing the irradiation position MP of the measurement light MB in the light receiving unit 24 so that the relative position R in the light receiving unit 24 becomes the derived relative position R. As a result, the adjusted relative position R, which is the irradiation position MP of the measurement light MB after adjustment relative to the irradiation position LP of the reflected light in the light receiving unit 24, coincides with the derived relative position R (FIG. 5).

Furthermore, in S108, the control device 30 moves the reflector 21 and the beam terminator 22 to the first position P1. This causes the processing light LB and the measurement light MB to be irradiated onto the workpiece W. At this time, since the relative position R in the light receiving unit 24 has been adjusted, the irradiation position of the processing light LB on the workpiece W and the irradiation position of the measurement light MB are aligned.

In this way, in the second and subsequent optical adjustments, the irradiation position of the processing light LB on the workpiece W can be aligned with the irradiation position of the measurement light MB without scanning the microhole with the measurement light MB, so the control device 30 can easily perform optical adjustments. Furthermore, compared to scanning the measurement light MB to derive the irradiation position of the measurement light MB corresponding to the lowest point of the microhole, the control device 30 can more accurately derive the irradiation position of the measurement light MB relative to the irradiation position of the processing light LB when deriving the irradiation position MP of the measurement light MB relative to the irradiation position LP of the processing light LB on the light receiving unit 24. Therefore, the control device 30 can highly accurately align the irradiation position of the processing light LB on the workpiece W with the irradiation position of the measurement light MB. Furthermore, in the second optical adjustment, it is not necessary to prepare a workpiece for adjustment.

According to the above-mentioned embodiment, the laser processing device 1 includes a laser oscillator 5 that emits processing light LB to the workpiece W, a measurement unit 3 that emits measurement light MB for measuring the irradiation position of the processing light LB on the workpiece W, a relative position derivation unit 20 that derives the relative position of the optical axis of the measurement light MB to the optical axis of the processing light LB, and a second mirror 11 that changes the optical path of the measurement light MB based on the relative position R derived by the relative position derivation unit 20.

This makes it possible to easily and accurately align the irradiation position of the processing light LB and the irradiation position of the measurement light MB on the workpiece W.

The laser processing device 1 further includes a first mirror 8 and a second mirror 11 that reflect the measurement light MB toward the irradiation position of the processing light LB on the workpiece W, and a first lens 9 that is disposed between the first mirror 8 and the second mirror 11 and the workpiece W and that converges the processing light LB and the measurement light MB on the workpiece W. The relative position derivation unit 20 is disposed between the first mirror 8 and the second mirror 11 and the first lens 9.

This allows the relative position derivation unit 20 to derive the relative position of the optical axis of the measurement light MB with respect to the optical axis of the processing light LB, including the effect of changes in the optical path of the measurement light MB caused by the displacement of the first mirror 8 and the second mirror 11.

The relative position derivation unit 20 also includes a reflector 21 that reflects the processing light LB and the measurement light MB in a direction other than the direction toward the workpiece W, and a light receiving unit 24 that receives the processing light LB and the measurement light MB reflected by the reflector 21. The relative position R is derived based on the irradiation position LP of the processing light LB and the irradiation position MP of the measurement light MB on the light receiving unit 24.

This makes it possible to more easily and accurately align the irradiation position of the processing light LB and the irradiation position of the measurement light MB on the workpiece W.

In addition, the reflectance of the processing light LB from the reflecting portion 21 is set to be equal to or lower than a predetermined value.

This allows the intensity of the reflected light irradiated to the light receiving unit 24 and the intensity of the measurement light MB to be within a predetermined range, so that the irradiation position MP of the measurement light MB relative to the irradiation position LP of the reflected light can be easily derived using a single light receiving unit 24, without using multiple light receiving units 24. This is because, if either the intensity of the reflected light or the intensity of the measurement light MB falls outside the predetermined range, a light receiving unit 24 corresponding to each intensity is required.

The laser processing device 1 further includes a measurement processing unit 4 that measures the depth of the processing point WP. The second mirror 11 changes the optical path of the measurement light MB so as to match the irradiation position of the processing light LB on the workpiece W with the irradiation position of the measurement light MB based on the depth of the processing point WP measured by the measurement processing unit 4, and changes the optical path of the measurement light MB based on the relative position R derived by the relative position derivation unit 20 when the irradiation position of the processing light LB on the workpiece W and the irradiation position of the measurement light MB are aligned.

This makes it possible to more reliably and accurately align the irradiation position of the processing light LB and the irradiation position of the measurement light MB on the workpiece W.

The measurement processing unit 4 is an interferometer that measures the length of the optical path of the measurement light MB based on the waveform that is generated by interference between the measurement light MB and the light reflected by the workpiece W.

This allows the laser processing device 1 to accurately derive the irradiation position of the measurement light MB on the workpiece W.

This disclosure is not limited to the embodiments described above. As long as they do not deviate from the spirit of the present invention, various modifications to the present embodiments and forms constructed by combining components of different embodiments are also included within the scope of the present invention.

For example, the flowchart shown in FIG. 3 has been described as a program executed by the control device 30, but each step of the flowchart in FIG. 3 may be executed by a user of the laser processing device 1. In this case, the control device 30 includes a display unit (not shown) that displays the relative position R in the light receiving unit 24, and an operation unit (not shown) that allows the user to switch the positions of the reflecting unit 21 and the beam terminator 22 and adjust the angle of the second mirror 11.

The relative position R in the light receiving unit 24 is adjusted by displacing the irradiation position MP of the measurement light MB in the light receiving unit 24. Alternatively, the relative position R in the light receiving unit 24 may be adjusted by displacing the irradiation position LP of the reflected light in the light receiving unit 24. In this case, for example, an angle adjustment mechanism may be arranged in the processing light inlet 7, and the control device 30 may control this angle adjustment mechanism to change the optical path of the processing light LB. Note that angle adjustment mechanisms may be arranged in both the second mirror 11 and the processing light inlet 7, and the control device 30 may control both angle adjustment mechanisms to change the optical path of the processing light LB and the optical path of the measurement light MB to adjust the relative position R in the light receiving unit 24. The angle adjustment mechanism arranged in the second mirror 11 may also be arranged in the measurement light inlet 6. Furthermore, each angle adjustment mechanism may be controlled by the control device 30 or may be manual.

In the above-described embodiment, the relative position derivation unit 20 includes one reflector 21, but may include multiple reflectors. In this case, as shown in FIG. 6, the relative position derivation unit 20 may include a first reflector 21a that moves between the first position P1 and the second position P2, and a second reflector 21b that reflects the reflected light and measurement light MB reflected by the first reflector 21a toward the second lens 23 and the light receiving unit 24. In this case, multiple beam terminators 22 are provided to correspond to the number of reflectors 21. The transmitted light transmitted from the first reflector 21a is terminated by the first beam terminator 22a. The transmitted light transmitted through the second reflector 21b is terminated by the second beam terminator 22b. In this way, by providing multiple reflectors 21, the intensity of the reflected light and the intensity of the measurement light MB can be adjusted within a predetermined range even when the intensity of the processing light LB and the intensity of the measurement light MB are relatively large.

The reflecting unit 21 uses a mirror that splits the processing light LB into transmitted light and reflected light, but in addition to this, a mirror that totally reflects the processing light LB may be provided. In this case, the beam terminator 22 may not be provided.

In addition, in the above-described embodiment, the processing light LB and the measurement light MB are reflected by the reflecting unit 21, pass through the second lens 23, and then irradiated to the light receiving unit 24. Alternatively, the processing light LB and the measurement light MB may pass through the second lens 23, be reflected by the reflecting unit 21, and then be irradiated to the light receiving unit 24. In this case, the second lens 23 is arranged to be movable. With this, even if a second lens 23 with a long focal length is selected, the optical paths of the reflected light and the measurement light MB are bent, so that the size of the relative position derivation unit 20 can be prevented from increasing.

The relative position derivation unit 20 may also be composed of two light receiving units (not shown). The first light receiving unit is disposed between the processing light inlet 7 and the first mirror 8 in the second optical adjustment, and the processing light LB is irradiated to the first light receiving unit. The second light receiving unit is disposed between the collimator lens 10 and the second mirror 11 in the second optical adjustment, and the measurement light MB is irradiated to the second light receiving unit. The center of the processing light LB irradiated to the first light receiving unit corresponds to the optical axis of the processing light. Also, the center of the measurement light irradiated to the second light receiving unit corresponds to the optical axis of the measurement light MB. Therefore, the control device 30 can directly derive the relative position of the optical axis of the measurement light MB to the optical axis of the processing light LB based on the center position of the processing light LB irradiated to the first light receiving unit and the center position of the measurement light MB irradiated to the second light receiving unit. In this case, the control device 30 controls the angle adjustment mechanism arranged in the measurement light inlet 6 to adjust the angle of the measurement light inlet 6 and change the optical path of the measurement light MB.

In addition, in the above-described embodiment, the reflecting portion 21 is formed in a plate shape, but it may have a shape other than a plate shape as long as the portion that reflects the processing light LB and the measurement light MB is planar.

The relative position derivation unit 20 is also provided with a beam terminator 22, but alternatively, if the intensity of the transmitted light is relatively small, the beam terminator 22 may not be provided.

The reflecting unit 21 also totally reflects the measurement light MB, but instead, the reflectance may be set to separate the measurement light MB into reflected light and transmitted light. In this case, the relative position R at the light receiving unit 24 can be derived in real time while the workpiece W is being processed, so that the irradiation position of the processing light LB on the workpiece W and the irradiation position of the measurement light MB can be aligned in real time while the workpiece W is being processed.

When a laser beam (e.g., a single-mode fiber laser) is used that has a beam diameter of 50 μm or less at the processing point WP, the adjustment accuracy of the irradiation position of the processing light LB and the irradiation position of the measurement light MB is required to be 10 μm or less, but the optical adjustment of the laser processing device 1 described above can meet this required accuracy.

The first optical adjustment is performed by scanning the minute hole formed at the processing point WP with the measurement light MB as described above, but instead, as shown in FIG. 7, it may be performed using a plate member 140 in which a slit 141 is formed and a power meter 150 that detects the intensity of the processing light LB.

In this case, the control device 30 changes the optical path of the processing light LB so that the processing light LB scans the slit 141, and detects the change in intensity of the processing light LB using the power meter 150. Based on this detected change in intensity of the processing light LB, the control device 30 adjusts the relative position of the optical path of the processing light LB with respect to the slit 141. Similarly, the control device 30 adjusts the relative position of the optical path of the measurement light MB with respect to the slit 141 to align the irradiation position of the processing light LB on the workpiece W with the irradiation position of the measurement light MB.

The mirrors that reflect the measurement light MB toward the irradiation position of the processing light LB on the workpiece W are the first mirror 8 and the second mirror 11, but it goes without saying that the number of mirrors is not limited to this. For example, the number of mirrors may be two or more. The position of the measurement light inlet 6 may also be changed to reduce the number of mirrors to one. In this case, for example, the measurement light inlet 6 and the collimating lens 10 may be positioned to the right of the first mirror 8, and the only mirror may be the first mirror 8. In this case, an angle adjustment mechanism may be provided on the first mirror 8.

The first mirror 8 has the property of transmitting the processing light LB and reflecting the measurement light MB, but instead, it may have the property of transmitting the measurement light MB and reflecting the processing light LB. In this case, for example, the processing light LB is incident on the first mirror 8 from the right, and the measurement light MB is incident on the first mirror 8 from above. The first mirror 8 may have the property of reflecting both the processing light LB and the measurement light MB. In this case, for example, the processing light LB and the measurement light MB are incident on the first mirror 8 from the right. In this way, the first mirror reflects at least one of the processing light LB and the measurement light MB toward the workpiece W.

The laser processing apparatus and the optical adjustment method for the laser processing apparatus disclosed herein can be used in devices that use laser light, such as laser welding machines and laser surface treatment devices.

1 Laser processing device 2 Processing head 3 Measurement unit (measurement light emission unit)
4. Measurement processing section (measurement section)
5 Laser oscillator (laser light emission unit)
6 Measurement light inlet 7 Processing light inlet 8 First mirror (mirror)
9 First lens (lens)
10 Collimator lens 11 Second mirror (optical path changing section, mirror)
20 Relative position derivation section 21 Reflection section 22 Beam terminator 23 Second lens 24 Light receiving section 30 Control device LB Processing light LP Irradiation position of processing light on light receiving section MB Measurement light MP Irradiation position of measurement light on light receiving section R Relative position W Workpiece

Claims (7)

a laser light emitting unit that emits a laser light for processing a workpiece;
a measurement light emitting unit that emits measurement light for measuring an irradiation position of the laser light on the workpiece;
a relative position deriving unit that derives a relative position of an optical axis of the measurement light with respect to an optical axis of the laser light;
an optical path changing unit that changes an optical path of at least one of the laser light and the measurement light based on the relative position derived by the relative position derivation unit;
A measuring unit for measuring the depth of the processing point,
The optical path change unit is
changing an optical path of at least one of the laser light and the measurement light so as to align an irradiation position of the laser light and an irradiation position of the measurement light on the workpiece based on the depth of the processing point measured by the measurement unit;
changing an optical path of at least one of the laser light and the measurement light based on the relative position derived by the relative position derivation unit when the irradiation position of the laser light and the irradiation position of the measurement light on the workpiece are aligned;
Laser processing equipment. a mirror that reflects at least one of the laser light and the measurement light toward the workpiece;
a lens disposed between the mirror and the workpiece to converge the laser light and the measurement light on the workpiece;
The relative position derivation unit is disposed between the mirror and the lens.
The laser processing device according to claim 1. The relative position derivation unit
a reflecting section that reflects the laser light and the measurement light in a direction other than the direction toward the workpiece;
a light receiving unit that receives the laser light and the measurement light reflected by the reflecting unit,
deriving the relative position based on an irradiation position of the laser light and an irradiation position of the measurement light on the light receiving unit;
3. The laser processing apparatus according to claim 1 or 2. The reflectance of the laser light of the reflecting portion is set to be equal to or less than a predetermined value.
The laser processing apparatus according to claim 3. The relative position derivation unit includes a plurality of the reflecting units.
5. The laser processing apparatus according to claim 3 or 4. the measurement unit is an interferometer that measures the length of an optical path of the measurement light based on a waveform generated by interference between the measurement light and light reflected by the workpiece,
The laser processing apparatus according to any one of claims 1 to 5. 1. An optical adjustment method for a laser processing apparatus including a laser light emitting unit that emits laser light to a workpiece , a measurement light emitting unit that emits measurement light for measuring an irradiation position of the laser light on the workpiece, and a measurement unit that measures a depth of a processing point, comprising:
a relative position deriving step of changing an optical path of at least one of the laser light and the measurement light so as to align an irradiation position of the laser light and an irradiation position of the measurement light on the workpiece based on the depth of the processing point measured by the measurement unit, and deriving a relative position of the optical axis of the measurement light with respect to the optical axis of the laser light when the irradiation position of the measurement light is aligned;
changing an optical path of at least one of the laser light and the measurement light based on the relative position derived in the relative position derivation step and the relative position derived after the relative position derivation step;
A method for adjusting the optics of a laser processing device.

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