Laser processing apparatus and optical adjustment method

A laser processing apparatus emits processing light, measurement light, processing guide light, and measurement guide light with which a surface of a workpiece is irradiated. Respective wavelengths of the processing guide light and the measurement guide light are set to wavelengths at which a deviation amount between an irradiation position of the processing guide light and an irradiation position of the measurement guide light due to a chromatic aberration of magnification of a lens, and a deviation amount between an irradiation position of the processing light and an irradiation position of the measurement light due to the chromatic aberration of magnification of the lens are equal to each other. Therefore, positioning of spot positions of a plurality of laser lights having different output differences can be realized with high accuracy and high speed.

CROSS-REFERENCE OF RELATED APPLICATIONS

This application claims the benefit of Japanese Patent Application No. 2019-156755, filed on Aug. 29, 2019, the entire disclosure of which Application is incorporated by reference herein.

BACKGROUND

1. Technical Field

The present disclosure relates to a laser processing apparatus used for processing, drilling, welding, cutting, or the like, and an optical adjustment method for adjusting spot positions of a plurality of lights emitted from the laser processing apparatus.

2. Description of the Related Art

In the related art, a laser light positioning technique performed using a slit is disclosed in, for example, Japanese Patent Unexamined Publication No. 2008-93682 (hereinafter referred to as “Patent Document 1”).

Hereinafter, the laser light positioning technique disclosed in Patent Document 1 will be described with reference toFIGS.13and14.

FIG.13is a perspective view illustrating an external appearance of a laser light positioning device disclosed in Patent Document 1.FIG.14is a side sectional view of the positioning device illustrated inFIG.13.FIG.14illustrates a positional relationship between laser light108emitted from laser head107, adjustment wafer100provided with slit102, and laser power meter101.

As illustrated inFIG.13, in the laser light positioning device of Patent Document 1, slit102provided on adjustment wafer100is moved in a direction of a double arrow illustrated inFIG.13by the rotation of support shaft103.

As illustrated inFIG.14, in the laser light positioning device of Patent Document 1, laser light108is emitted from laser head107. Laser light108reaches laser power meter101along optical axis109unless there is an obstacle.

The positioning device of Patent Document 1 includes support shaft103, Z-direction driver104, R-direction driver105, adjustment wafer100, laser head base106, laser head107, laser power meter101, and the like. Respective positions of adjustment wafer100and laser head107are relatively moved by support shaft103, Z-direction driver104, and R-direction driver105. An output of laser power meter101due to the relative movement is observed. In this case, a focus position of laser light108is aligned with a position of slit102. Thereby, a position of laser light108can be adjusted to a desired position.

In the related art, it is also realized that a beam profiler using a two-dimensional light receiving element is used to directly detect laser light spot position coordinates in a plane and adjusts the position of the laser light. As the two-dimensional light receiving element, for example, a complementary metal oxide semiconductor (CMOS) element which is an image pickup element, or the like is exemplified.

In recent years, an evaluation method for observing a welding step in real time by combining a laser welding device and an optical coherence tomography (OCT) has been disclosed, for example, in Published Japanese Translation No. 2016-538134 of the PCT International Publication (hereinafter referred to as “Patent Document 2”). However, in order to realize the evaluation method of Patent Document 2, precise positioning of the processing laser light and the measurement light is very important. Therefore, in recent years, adjustment of the spot position of the laser light has become an indispensable technique.

However, in the laser light positioning device of Patent Document 1, in a case where a spot diameter at the focal position of laser light108is extremely small, it is necessary to narrow a slit width of slit102according to the spot diameter. If the slit width is narrow, it is difficult to quickly capture the spot position of laser light108in slit102in an initial stage of adjustment. That is, in the positioning device of Patent Document 1, it is difficult to realize positioning with high accuracy and high speed.

SUMMARY

The present disclosure provides a laser processing apparatus and an optical adjustment method capable of realizing positioning of spot positions of a plurality of laser lights having different output differences with high accuracy and high speed.

A laser processing apparatus according to an aspect of the present disclosure includes: a laser oscillator that emits processing light with which a processing point of a surface of a workpiece is irradiated; and a measurement unit that emits measurement light with which the processing point is irradiated, and detects the measurement light reflected at the processing point. The laser processing apparatus further includes a mirror that combines the processing light and the measurement light; a lens that condenses the processing light and the measurement light on the processing point; and a measurement processor that performs a predetermined measurement based on a signal from the measurement unit. The laser oscillator and the measurement unit emit processing guide light and measurement guide light respectively with which a surface of the workpiece is irradiated for adjusting a deviation between an irradiation position of the processing light and an irradiation position of the measurement light on the surface of the workpiece. Respective wavelengths of the processing guide light and the measurement guide light are set to wavelengths at which a deviation amount between an irradiation position of the processing guide light and an irradiation position of the measurement guide light due to a chromatic aberration of magnification of the lens, and a deviation amount between the irradiation position of the processing light and the irradiation position of the measurement light due to the chromatic aberration of magnification of the lens are equal to each other.

One aspect of the present disclosure is an optical adjustment method performed by a laser processing apparatus that emits processing light, measurement light, processing guide light, and measurement guide light with which a surface of a workpiece is irradiated. In the optical adjustment method, in a first optical adjustment, aligning an irradiation position of the processing light with an irradiation position of the measurement light without using the processing guide light and the measurement guide light, and recording a deviation amount between an irradiation position of the processing guide light and an irradiation position of the measurement guide light, as a deviation amount of an initial adjustment position. In the optical adjustment method, in second and subsequent optical adjustments, adjusting a deviation amount between an irradiation position of the processing guide light and an irradiation position of the measurement guide light so as to be equal to the deviation amount of the initial adjustment position.

According to the present disclosure, it is possible to provide a laser processing apparatus and an optical adjustment method capable of realizing positioning of spot positions of a plurality of laser lights having different output differences with high accuracy and high speed.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings. The same reference numerals are given to common constituent elements in each drawing, and the description thereof will be appropriately omitted.

Exemplary Embodiments

Hereinafter, the laser processing apparatus and the optical adjustment method according to exemplary embodiments of the present disclosure will be described by dividing them into items.

<Configuration of Laser Processing Apparatus>

First, a configuration of laser processing apparatus1according to the exemplary embodiment of the present disclosure will be described with reference toFIG.1.

FIG.1is a view schematically illustrating the configuration of laser processing apparatus1according to the present exemplary embodiment.

As illustrated inFIG.1, laser processing apparatus1according to the present exemplary embodiment includes processing head2, measurement unit3, measurement processor4, laser oscillator5, and the like.

Measurement unit3is, for example, an optical interferometer for OCT measurement. Measurement unit3emits measurement light6which is laser light for the OCT measurement. Emitted measurement light6is input from measurement light inlet8to processing head2.

Laser oscillator5oscillates processing light7which is laser light for laser processing. Oscillated processing light7is input from processing light inlet9to processing head2.

Processing light7input to processing head2passes through first mirror10(may be simply referred to as “mirror”) and lens11, and is condensed on processing surface13on a surface of workpiece12. Therefore, processing point14on processing surface13of workpiece12is laser-processed. In this case, workpiece12at processing point14irradiated with processing light7is melted and molten pool15is formed. A molten metal is evaporated from formed molten pool15. Therefore, keyhole16is formed in workpiece12by a pressure of vapor generated during evaporation.

On the other hand, measurement light6input to processing head2is converted into parallel light by collimating lens17and reflected by second mirror18and first mirror10(mirror). Second mirror18and first mirror10(mirror) constitute an adjustment mechanism that adjusts the irradiation positions of processing light7and measurement light6described later.

After that, reflected measurement light6passes through lens11and is condensed on processing point14on the surface of workpiece12. Condensed measurement light6is reflected by a bottom surface of keyhole16and traces the propagation path to reach measurement unit3. Measurement unit3generates an optical interference intensity signal based on interference generated by an optical path difference between the measurement light reflected by keyhole16and reference light.

Measurement processor4measures a depth of keyhole16, that is, a penetration depth of processing point14based on the optical interference intensity signal generated by measurement unit3. The “penetration depth” means a distance between a highest point of a melted portion of workpiece12and processing surface13.

In general, a wavelength of processing light7and a wavelength of measurement light6are different. Specifically, in a case where a YAG laser or a fiber laser is used as processing light7, the wavelength of processing light7is 1064 nm. On the other hand, in a case where an OCT light source is used as measurement light6, the wavelength of measurement light6is 1300 nm.

First mirror10(mirror) is, for example, a dichroic mirror. Therefore, first mirror10has characteristics of transmitting the light of the wavelength of processing light7and reflecting the light of the wavelength of measurement light6.

Usually, in laser processing apparatus1, high-power laser light is used as processing light7. Therefore, a temperature change occurs in a body of processing head2, a fixed portion of an optical component configuring processing head2, or the like due to absorption of reflected light from processing surface13of workpiece12, reflected light in the optical component configuring processing head2, absorption of heat, or the like.

The temperature change changes a fixed state (for example, a position where the optical component is fixed) of the optical component configuring processing head2. Therefore, an incident angle of each of processing light7and measurement light6on lens11changes. As a result, a deviation occurs in arrival positions (also referred to as spot positions, hereinafter, referred to as “irradiation positions”) of processing light7and measurement light6on processing surface13of workpiece12. Therefore, second mirror18of the present exemplary embodiment is provided with an adjustment mechanism capable of changing the angle of measurement light6in two or more axes. Thus, it is possible to adjust the deviation between the irradiation positions of processing light7and measurement light6.

Specifically, the deviation of the irradiation position is adjusted by using measurement guide light19and processing guide light20. Measurement guide light19is emitted from measurement unit3and input from measurement light guide inlet8to processing head2. Processing guide light20is emitted from laser oscillator5and input from processing light inlet9to processing head2.

In the following description, measurement guide light19and processing guide light20may be collectively referred to as “guide light”.

<Problem of Optical Adjustment with Guide Light>

Next, a problem in a case of adjusting the irradiation position of processing light7and the irradiation position of measurement light6by using the guide light will be described with reference toFIG.2.

In general, red guide light is often used as the guide light for reasons such as visibility. As an example, a case where both processing guide light20and measurement guide light19are red laser light having a wavelength of 635 nm will be described.

As described above, the wavelength of processing light7and the wavelength of measurement light6are different from each other. Therefore, when processing light7and measurement light6pass through lens11, a chromatic aberration occurs in processing light7and measurement light6.

The chromatic aberration is an aberration that occurs because a general optical material including lens11has a property that a refractive index varies depending on the wavelength of light.

There are two types of the chromatic aberration of an axial chromatic aberration and a chromatic aberration of magnification. The axial chromatic aberration is an aberration due to a property that the focal position of the lens varies depending on the wavelength of light. On the other hand, the chromatic aberration of magnification is an aberration due to a property that an image height on a focal plane varies depending on the wavelength of light.

FIG.2is a view illustrating an example of the chromatic aberration of magnification of processing light7and measurement light6by lens11. InFIG.2, processing light irradiation position21that is the irradiation position of processing light7is illustrated by a solid line, and measurement light irradiation position22that is the irradiation position of measurement light6is illustrated by a broken line.

As illustrated inFIG.2, in the vicinity of lens center23, processing light irradiation position21and measurement light irradiation position22on processing surface13match with each other. However, as a distance from lens center23increases, the deviation between processing light irradiation position21and measurement light irradiation position22on processing surface13increases. That is, as illustrated inFIG.2, in a case where processing light irradiation position21has a lattice-shaped pattern without distortion, measurement light irradiation position22has a distorted bobbin-shaped pattern. That is, in a case where the irradiation position of processing light7and the irradiation position of measurement light6match with each other on processing surface13of workpiece12, it can be seen that an adjustment amount of the irradiation position of measurement light6varies depending on the irradiation position of processing light7.

Hereinafter, a case where the respective irradiation positions of processing light7and measurement light6are adjusted by using red processing guide light20and measurement guide light19having the same wavelength will be described with reference toFIG.3.

FIG.3is a view schematically illustrating an example of a case where the respective irradiation positions of processing light7and measurement light6are adjusted by using red processing guide light20and measurement guide light19having the same wavelength.

InFIG.3, it is assumed that the respective optical axes of processing light7and processing guide light20incident on lens11match with each other. Similarly, it is assumed that the respective optical axes of measurement light6and measurement guide light19incident on lens11match with each other.

As illustrated inFIG.3, in a case where irradiation position24of each of processing guide light20and measurement guide light19is made be matched and the optical adjustment is performed, the respective optical axes of processing light7and measurement light6incident on lens11match with each other. The respective irradiation positions of processing guide light20and measurement guide light19are detected by a laser position detection sensor (for example, a two-dimensional light receiving element) (not illustrated) provided outside laser processing apparatus1.

It is assumed that the respective optical axes of processing light7and measurement light6incident on lens11are inclined with respect to the central axis (lens center23illustrated inFIG.3) of lens11due to an adjustment error of optical adjustment, a change in the fixed state of the optical component configuring processing head2, or the like. In this case, as illustrated inFIG.3, a deviation occurs between irradiation position25of processing light7and irradiation position26of measurement light6due to the influence of the chromatic aberration of magnification.

Specifically, for example, it is assumed that processing light7has a wavelength of 1070 nm and measurement light6has a wavelength of 1310 nm. It is assumed that lens11is a commercially available lens and its focal length is 255 mm. The incident angle of each of processing light7and measurement light6on lens11is 0.5 deg. In this case, due to the chromatic aberration of magnification of lens11, a deviation of substantially 0.025 mm occurs between irradiation position25of processing light7and irradiation position26of measurement light6.

In reality, there are errors in respective optical axes of processing light7and processing guide light20, and respective optical axes of measurement light6and measurement guide light19incident on lens11. That is, the deviation between irradiation position25of processing light7and irradiation position26of measurement light6is larger than the value described above.

Therefore, the deviation between irradiation position25of processing light7and irradiation position26of measurement light6is a factor that greatly deteriorates the measurement accuracy of keyhole16. Therefore, sufficient adjustment accuracy cannot be obtained in the optical adjustment configuration by the guide light of the related art described above.

Therefore, in the present exemplary embodiment, optical adjustment with sufficient adjustment accuracy is possible by selecting the wavelength of the guide light described below.

<Selection Method of Wavelength of Guide Light>

Next, a selection method of the wavelength of the guide light according to the present exemplary embodiment will be described.

Specifically, in the present exemplary embodiment, as the wavelengths of processing guide light20and measurement guide light19, the following wavelengths having mutual deviation amounts equal to each other are selected. The mutual deviation amounts are the deviation amount generated between the irradiation position of processing light7and the irradiation position of measurement light6due to the chromatic aberration of magnification of lens11, and the deviation amount generated between the irradiation position of processing guide light20and the irradiation position of measurement guide light19due to the chromatic aberration of magnification of lens11.

Hereinafter, a flow of the selection method of the wavelength of the guide light according to the present exemplary embodiment will be described with reference toFIG.4.

FIG.4is a flowchart illustrating the flow of the selection method of the wavelength of the guide light according to the present exemplary embodiment. Each step of the flowchart ofFIG.4is performed, for example, by a designer of laser processing apparatus1, an operator who performs the optical adjustment, or the like.

First, as illustrated inFIG.4, the deviation amount between irradiation position25of processing light7and irradiation position26of measurement light6is obtained in a case where processing light7and measurement light6are respectively incident on lens11at a specific incident angle (step S101).

In the present exemplary embodiment, as an example, as described above, a commercially available lens having a focal length of 255 mm was used as lens11in advance and the incident angle of processing light7and measurement light6with respect to lens11was 0.5 deg. In this case, the deviation amount (for example, corresponding to deviation amount27illustrated inFIG.6) was obtained by an optical simulation. As a result, the deviation amount was 0.025 mm.

Next, a correspondence relationship between the candidate (hereinafter referred to as “wavelength candidate”) of the wavelength used for the guide light incident on lens11at a specific incident angle and the irradiation position is obtained (step S102).

Specifically, as illustrated inFIG.5, the correspondence relationship between the wavelength candidate and the irradiation position was obtained. InFIG.5, a horizontal axis indicates the wavelength (wavelength candidate) and a vertical axis indicates the irradiation position.

The wavelength candidate illustrated inFIG.5was selected based on a wavelength of a commercially available laser. In other words, the wavelength candidate was selected from a wavelength band (for example, 300 nm to 1100 nm) that can be measured by a charged coupled devices (CCD) or CMOS. The irradiation position corresponding to each wavelength candidate was obtained by an optical simulation.

FIG.5also illustrates the respective irradiation positions of different wavelengths, for example, the wavelength (1070 nm) of processing light7and the wavelength (1310 nm) of measurement light6.

Next, a combination of wavelength candidates having a same deviation amount as the deviation amount obtained in step S101is obtained (step S103).

From the flow described above, in the present exemplary embodiment, fromFIG.5, for example, 650 nm and 785 nm at which the deviation amount of the irradiation position is 0.025 mm were selected as an example of a combination of wavelength candidates.

In the present exemplary embodiment, a target accuracy of the optical adjustment of each of processing light7and measurement light6was set to ±0.010 mm. Therefore, in step S103, the deviation amount within 0.010 mm with respect to the deviation amount obtained in step S101is regarded as the same deviation amount as the deviation amount obtained in step S101, and the combination of wavelength candidates was selected.

The wavelength selected as described above was used as the wavelength of processing guide light20and measurement guide light19. Specifically, for example, the selected 650 nm was used as the wavelength of processing guide light20, and the selected 785 nm was used as the wavelength of measurement guide light19. 1070 nm illustrated inFIG.5was used as the wavelength of processing light7, and 1310 nm was used as the wavelength of measurement light6.

<Relationship Between Irradiation Positions of Processing Light, Measurement Light, and Guide Light>

Next, in a case where processing guide light20and measurement guide light19having the wavelengths selected by the selection method of the wavelength of the guide light described above are used, a relationship between the respective irradiation positions of processing light7, measurement light6, processing guide light20, and measurement guide light19will be described with reference toFIG.6.

FIG.6is a view schematically illustrating the relationship between the respective irradiation positions of processing light7, measurement light6, processing guide light20, and measurement guide light19according to the present exemplary embodiment.

As illustrated inFIG.6, in a case where the respective optical axes of processing light7, measurement light6, processing guide light20, and measurement guide light19incident on lens11match with each other, irradiation position25of processing light7and irradiation position26of measurement light6are deviated by deviation amount27due to the chromatic aberration of magnification of lens11.

On the other hand, in a case where the respective optical axes of processing light7, measurement light6, processing guide light20, and measurement guide light19incident on lens11match with each other, irradiation position28of processing guide light20and irradiation position29of measurement guide light19are deviated by deviation amount30due to the chromatic aberration of magnification of lens11.

In this case, deviation amount27and deviation amount30respectively have the same direction and size.

In a case where the angle of the optical axis of each light incident on lens11changes, the direction and size of deviation amount27change. However, even if the angle of the optical axis of each light changes, the direction and size of deviation amount30change while maintaining the same relationship with the direction and size of deviation amount27.

Hereinafter, a first example of adjusting the irradiation position by using processing guide light20and measurement guide light19having the relationship described above will be described with reference toFIG.7.

FIG.7is a view schematically illustrating a first example in which the irradiation position is adjusted by using processing guide light20and measurement guide light19according to the present exemplary embodiment.

InFIG.7, it is assumed that the respective optical axes of processing light7and processing guide light20incident on lens11match with each other. It is assumed that the respective optical axes of measurement light6and measurement guide light19incident on lens11match with each other.

The angle of second mirror18illustrated inFIG.1is adjusted so that irradiation position28of processing guide light20illustrated inFIG.6and irradiation position29of measurement guide light19illustrated inFIG.6match with each other. Thereby, the respective incident angles of measurement guide light19and measurement light6on the lens11are changed at the same time.

In this case, as described above, the respective directions and sizes of deviation amount27and deviation amount30illustrated inFIG.6are maintained in the same relationship. That is, irradiation position26of measurement light6changes so that irradiation position25of processing light7illustrated inFIG.6and irradiation position26of measurement light6illustrated inFIG.6match with each other.

As described above, as illustrated inFIG.7, irradiation position28of processing guide light20and irradiation position29of measurement guide light19match with each other. At the same time, irradiation position25of processing light7and irradiation position26of measurement light6match with each other.

That is, in laser processing apparatus1according to the present exemplary embodiment, processing guide light20and measurement guide light19are used, which have the wavelengths selected by the selection method of the wavelength of the guide light. Accordingly, irradiation position25of processing light7and irradiation position26of measurement light6can be matched without being affected by the chromatic aberration of magnification of lens11.

<Optical Adjustment Method By Guide Light>

Next, an optical adjustment method using the guide light will be described with reference toFIG.8.

FIG.8is a flowchart illustrating a flow of the optical adjustment method by using the guide light according to the present exemplary embodiment. Each step of the flowchart inFIG.8may be performed by an operator who performs optical adjustment or the like. Some or all of the steps in the flowchart ofFIG.8may be performed by laser processing apparatus1for the purpose of automation.

After the selection method of the wavelength of the guide light described above is performed once, the optical adjustment method by using the guide light described below is repeatedly executed.

That is, as illustrated inFIG.8, first, it is determined whether or not a current optical adjustment is a first optical adjustment (step S201).

At this time, in a case where the current optical adjustment is the first optical adjustment (YES in step S201), irradiation position25of processing light7and irradiation position26of measurement light6are aligned without using the guide light (step S202).

The reason why step S202is performed will be described.

In the first example in which the irradiation position is adjusted by using processing guide light20and measurement guide light19described inFIG.7, it is assumed a case where the optical axes of processing light7and processing guide light20incident on lens11match with each other, and the optical axes of measurement light6and measurement guide light19incident on lens11match with each other. However, in reality, the respective optical axes may be deviated.

In this case, even if irradiation position28of processing guide light20and irradiation position29of measurement guide light19match with each other, the irradiation positions of processing light7and measurement light6are deviated.

Therefore, in the case of the first optical adjustment (YES in step S201), the irradiation positions of processing light7and measurement light6are adjusted without using the guide light.

Hereinafter, an optical adjustment method of the irradiation positions of processing light7and measurement light6will be described using a specific example.

First, processing surface13of workpiece12prepared for the optical adjustment is irradiated with processing light7to make a minute hole on processing surface13. After that, while adjusting the angle of second mirror18, a periphery of the minute hole is scanned by measurement light6to obtain a center portion (or a deepest portion) of the minute hole. The irradiation position of measurement light6is adjusted by using the obtained center portion of the minute hole as a center position of processing light7.

The method described above is an example of adjusting the respective irradiation positions of processing light7and measurement light6, and is not limited to this. For example, a method (for example, see Patent Document 1) of adjusting the irradiation position by using a slit and a power meter, or the like may be used for adjusting the irradiation position.

The reason why step S202is performed is described above. Hereinafter, it returns to the description of the flow ofFIG.8.

Next, the deviation amount between the initial adjustment position of processing guide light20and the initial adjustment position of measurement guide light19is obtained and recorded in a memory (not illustrated) or the like (step S203). The initial adjustment position is a position when the positioning (that is, the first optical adjustment) of the irradiation position in step S202is performed.

A specific example of step S203will be described with reference to FIG.9.

FIG.9is a diagram schematically illustrating the respective initial adjustment positions of processing guide light20and measurement guide light19according to the present exemplary embodiment.

In step S202ofFIG.8, even if the irradiation position of processing light7and the irradiation position of measurement light6match with each other, in the state described below, as illustrated inFIG.9, deviation amount30is generated between irradiation position28of processing guide light20and irradiation position29of measurement guide light19. This corresponds to a case where the respective optical axes of processing light7and processing guide light20incident on lens11are deviated, and the respective optical axes of measurement light6and measurement guide light19incident on lens11are deviated.

Specifically, in step S203, deviation amount30illustrated inFIG.9is obtained. Obtained deviation amount30is recorded in the memory (not illustrated) of laser processing apparatus1as the deviation amount of the initial adjustment position. The recorded deviation amount of the initial adjustment position is used in step S204, in which is the second and subsequent optical adjustments (NO in step S201) are performed.

The specific example of step S203is described above. Hereinafter, it returns to the description of the flow ofFIG.8.

As illustrated inFIG.8, when step S203ends, the first optical adjustment is completed.

In step S201, in a case where it is determined that the current optical adjustment is the second and subsequent times (NO in step S201), the irradiation position of measurement guide light19is adjusted (step S204) based on the deviation amount between the irradiation position of processing guide light20and the initial adjustment position.

A specific example of step S204will be described with reference toFIG.10.

FIG.10is a diagram schematically illustrating the irradiation positions of the processing guide light and the measurement guide light after the optical adjustment according to the present exemplary embodiment.

That is, in the second and subsequent optical adjustments, the fixing state of the optical component configuring processing head2may change due to the influence of heat caused by the use of laser processing apparatus1. When the fixed state of the optical component changes, the respective incident angles of processing light7and processing guide light20with respect to lens11simultaneously change. Therefore, the irradiation position of processing light7and the irradiation position of processing guide light20both move. For example, irradiation position28of processing guide light20illustrated inFIG.9moves to another irradiation position28as illustrated inFIG.10. As a result, a deviation occurs between the irradiation position of processing light7and the irradiation position of measurement light6.

Therefore, in step S204, the deviation amount between irradiation position28of processing guide light20and irradiation position29of measurement guide light19is adjusted by using second mirror18illustrated inFIG.1. Specifically, the deviation amount is adjusted by using second mirror18so that the deviation amount between irradiation position28of processing guide light20illustrated inFIG.10and irradiation position29of measurement guide light19illustrated inFIG.10is equal to the deviation amount (for example, deviation amount30illustrated inFIG.9) of the initial adjustment position obtained in step S203.

In this case, the respective coordinates of irradiation positions28and29illustrated inFIG.10are different from the respective coordinates of irradiation positions28and29illustrated inFIG.9, but deviation amount30is the same. That is, the relative positional relationships between irradiation positions28and29illustrated inFIGS.9and10match with each other.

Hereinafter, a second example of adjusting the irradiation position by using processing guide light20and measurement guide light19having the relationship described above will be described with reference toFIG.11.

FIG.11is a view schematically illustrating the second example in which the irradiation position is adjusted by using processing guide light20and measurement guide light19according to the present exemplary embodiment.

As described above, in the present exemplary embodiment, as the respective wavelengths of processing guide light20and measurement guide light19, wavelengths at which the deviation amounts of the irradiation positions described below are equal to each other are used. Specifically, the wavelengths are used such that the deviation amount between the irradiation position of processing light7and the irradiation position of measurement light6due to the chromatic aberration of magnification of lens11, and the deviation amount between the irradiation position of processing guide light20and the irradiation position of measurement guide light19due to the chromatic aberration of magnification of lens11are equal to each other.

Therefore, in a case where deviation amount30illustrated inFIG.10is equal to deviation amount30illustrated inFIG.9, inFIG.11, the deviation amount between the irradiation position of processing light7and the irradiation position of measurement light6matches with deviation amount30illustrated inFIG.9. That is, as illustrated inFIG.11, irradiation position25of processing light7and irradiation position26of measurement light6match with each other.

As described above, in step S204illustrated inFIG.8, it is possible to match the respective irradiation positions of processing light7and measurement light6only by using the guide light of processing guide light20and measurement guide light19.

The specific example of step S204is described above.

As illustrated inFIG.8, when step S204ends, the optical adjustment is completed.

As described above, in the second and subsequent optical adjustments, the optical adjustment can be performed only by using the guide light of processing guide light20and measurement guide light19.

Effects

Next, operations and effects of the present exemplary embodiment will be described with reference toFIG.12.

FIG.12is a table illustrating an optical simulation result of optical adjustment of the processing light and the measurement light by the guide light according to the present exemplary embodiment.

In the optical simulation of the present exemplary embodiment, the wavelength of processing light7was set to 1070 nm, and the wavelength of measurement light6was set to 1310 nm. An optical simulation was performed by setting the wavelength of processing guide light20to 650 nm and the wavelength of measurement guide light19to 785 nm.

The wavelength of processing guide light20and the wavelength of measurement guide light19are wavelengths such that the deviation amount between the irradiation position of processing light7and the irradiation position of measurement light6due to the chromatic aberration of magnification of lens11is equal to the deviation amount between the irradiation position of processing guide light20and the irradiation position of measurement guide light19due to the chromatic aberration of magnification of lens11.

In the optical simulation of the present exemplary embodiment, the angle deviation of the optical axis of processing guide light20with respect to processing light7incident on lens11was set to 0.1 deg. The angle deviation of the optical axis of measurement guide light19with respect to measurement light6incident on lens11was set to −0.05 deg.

In the present exemplary embodiment, an optical simulation was performed on the X-axis passing through lens center23(seeFIGS.2,3,6, and7).

The incident angle of processing light7on lens11was set to 0.5 deg at the time of initial adjustment in step S202ofFIG.8. On the other hand, at the time of the optical adjustment using the guide light in step S204ofFIG.8, the optical simulation was performed by setting to 1.0 deg, 1.5 deg, and 2.0 deg.

Based on the respective conditions described above, the deviation amount between the irradiation position of processing guide light20and the irradiation position of measurement guide light19is adjusted within an error range is 0.004 mm according to the deviation amount of the initial adjustment position. The deviation amount of the initial adjustment position is the deviation amount x=−1.310 mm of the irradiation position of the guide light when the incident angle of the processing light on the lens is 0.5 deg.

As a result of the adjustment described above, as illustrated inFIG.12, the deviation amount between the irradiation positions of processing light7and measurement light6could be adjusted within a range of 0 mm to 0.005 mm.

That is, according to the optical simulation of the present exemplary embodiment, it could be confirmed that the respective irradiation positions of processing light7and measurement light6can be adjusted with high accuracy only by using the guide light without being affected by the chromatic aberration of magnification of lens11.

Laser processing apparatus1of the present exemplary embodiment can use a low-power laser as the guide light. Therefore, the respective irradiation positions of processing light7and measurement light6can be adjusted, for example, only by a general-purpose laser position detection sensor such as a beam profiler or an area camera. Thereby, the optical adjustment can be performed at high speed.

In laser processing apparatus1of the present exemplary embodiment, the wavelength of the guide light is selected from a wavelength band (for example, 300 nm to 1100 nm) that can be measured by using charged coupled devices (CCD) or CMOS. Therefore, the optical adjustment can be performed with an inexpensive configuration.

As described above, according to laser processing apparatus1of the present exemplary embodiment, the positioning of the spot positions (irradiation positions) of a plurality of laser lights having different output differences can be realized with high accuracy, high speed, and low cost.

In the present exemplary embodiment, a case where irradiation position26of measurement light6is adjusted by using second mirror18which is an adjustment mechanism in the optical adjustment of processing light7and measurement light6is described as an example, but it is not limited to the exemplary embodiment. For example, an adjustment mechanism may be provided in the optical path of processing light7, and irradiation position25of processing light7may be adjusted via the adjustment mechanism. The adjustment mechanism used in the present exemplary embodiment may be a manual type or an electrically controlled type.

In the present exemplary embodiment, a case where the laser position detection sensor provided outside laser processing apparatus1is used in the optical adjustment of processing light7and measurement light6by using the guide light is described as an example, but it is not limited to the exemplary embodiment. For example, the laser position detection sensor may be mounted on laser processing apparatus1.

In this case, first, laser processing apparatus1moves the laser position detection sensor to a predetermined optical adjustment position.

Next, laser processing apparatus1controls the adjustment mechanism that adjusts the irradiation position of processing light7and the adjustment mechanism (for example, second mirror18) that adjusts the irradiation position of the measurement light6based on the respective irradiation positions of processing guide light20and measurement guide light19detected by the laser position detection sensor.

With this configuration, for example, in a case where it is necessary to periodically perform the optical adjustment in a continuously operating production line or the like, the optical adjustment can be automatically performed only by laser processing apparatus1. Therefore, the time required for the optical adjustment can be greatly reduced.

The present disclosure is not limited to the description of the exemplary embodiments described above, and various modifications can be made without departing from the spirit of the present disclosure.