Laser device and laser device control method

Abstract

A laser source (101) emits a laser beam (LB). An optical system (102) is configured to irradiate the laser beam (LB) emitted from the laser source (101) onto an irradiated object (20), and is capable of changing the beam profile of the laser beam (LB) irradiated onto the irradiated object (20). A profile detection unit (103) detects the beam profile of the laser beam (LB) irradiated from the optical system (102) onto the irradiated object (20). A control unit (14) controls the optical system (102) at each pre-set control cycle so that the beam profile detected by the profile detection unit (103) becomes a desired beam profile.

Description

Technical Field

[0001] The technology disclosed here relates to a laser device and a control method of the laser device. Background Art

[0002] Patent document 1 discloses a laser oscillator, which includes: a laser source for emitting laser light; and a focusing optical unit for reducing the laser light at a predetermined magnification and focusing the laser light on the incident end of a transmission optical fiber. The focusing optical unit includes: an optical component for imaging the incident laser light at a predetermined focal point, and is configured to be able to change the focal distance.

[0003] Prior Art Literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2020-060725 Summary of the invention

[0006] -Problems to be solved by the invention-

[0007] However, in the device of Patent Document 1, if the optical path of the optical system that guides the laser light emitted from the laser source to the irradiated object (the incident end of the transmission fiber in Patent Document 1) deviates, the beam profile of the laser light irradiated to the irradiated object changes.

[0008] Therefore, an object of the technology disclosed herein is to provide a laser device capable of suppressing a change in the beam profile of laser light caused by a deviation of an optical path of an optical system.

[0009] -Methods for solving the problem-

[0010] The technology disclosed here relates to a laser device for irradiating a laser onto an irradiated object, the laser device comprising: a laser source for emitting the laser; an optical system configured to irradiate the laser emitted from the laser source onto the irradiated object and capable of changing the beam profile of the laser irradiated onto the irradiated object; a contour detection unit for detecting the beam profile of the laser irradiated from the optical system onto the irradiated object; and a control unit for controlling the optical system at each predetermined control cycle so that the beam profile detected by the contour detection unit becomes a desired beam profile.

[0011] In addition, the technology disclosed herein relates to a control method for a laser device, the laser device comprising: a laser source emitting laser light; and an optical system configured to irradiate the laser light emitted from the laser source to the end of an optical fiber having a first core and a second core surrounding the first core, and capable of changing the beam profile of the laser light irradiated to the end of the optical fiber. The control method for the laser device comprises: a detection step of detecting the position of a light spot of the laser light at the end of the optical fiber; and a control step of controlling the optical system at each preset control cycle so that the position of the light spot detected by the detection step becomes a target light spot position corresponding to a desired beam profile.

[0012] -Effects of the Invention-

[0013] According to the technology disclosed herein, it is possible to suppress the variation of the beam profile of the laser light caused by the deviation of the optical path of the optical system. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is an exemplary diagram illustrating the configuration of the laser processing system according to the first embodiment.

[0015] Figure 2 This is an exemplary diagram illustrating the structure of the laser device according to the first embodiment.

[0016] Figure 3 This is a table illustrating the relationship between the incident state of laser light, the incident state of partial light, and the beam profile.

[0017] Figure 4 This is a flowchart illustrating the operation of the control unit in the first embodiment.

[0018] Figure 5 This is a flowchart illustrating the operation of the control unit in the second embodiment.

[0019] Figure 6 This is a flowchart illustrating the operation of the control unit of Modification 1 of Implementation 2.

[0020] Figure 7 This is a flowchart illustrating the operation of the control unit of Modification 2 of Implementation Example 2.

[0021] Figure 8 This is a flowchart illustrating the operation of the control unit in the third embodiment.

[0022] Fig. 9 This is a flowchart illustrating the operation of the control unit in the fourth embodiment.

[0023] Fig.10 This is an exemplary diagram illustrating the structure of the laser device according to the fifth embodiment.

[0024] Fig.11 This is a flowchart illustrating the operation of the control unit in the fifth embodiment.

[0025] Fig.12 This is an exemplary diagram illustrating the structure of the laser device according to the sixth embodiment.

[0026] Fig.13 This is a flowchart illustrating the operation of the control unit in the sixth embodiment.

[0027] Fig.14 This is an exemplary diagram illustrating the structure of a laser device of another type. DETAILED DESCRIPTION

[0028] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. In addition, the same reference numerals are given to the same or corresponding parts in the drawings, and their description will not be repeated.

[0029] (Implementation Method 1)

[0030] Figure 1 The structure of the laser processing system 1 of the first embodiment is exemplified. The laser processing system 1 uses laser LB to process a workpiece (not shown). Specifically, the laser processing system 1 cuts the workpiece by irradiating the workpiece with laser LB. In this example, the laser processing system 1 includes: a laser device 10, an optical fiber 20, and an output head 25. The laser device 10 irradiates the laser LB to the end (end face) of the optical fiber 20. In addition, the end of the optical fiber 20 is an example of an irradiated object.

[0031] 〔optical fiber〕

[0032] One end of the optical fiber 20 is connected to a laser oscillator 11 of the laser device 10, which will be described later, and the other end of the optical fiber 20 is connected to an output head 25. The optical fiber 20 guides the laser light LB emitted from the laser device 10 to the output head 25.

[0033] like Figure 2 As shown in the figure, in this example, the optical fiber 20 has: a first core 20a, a second core 20b surrounding the first core 20a, and a coating 20c surrounding the second core 20b. The cross-sectional shape of the first core 20a is circular. The cross-sectional shape of the second core 20b is annular. A first cladding not shown is provided between the second core 20b and the coating 20c, and a second cladding not shown is provided between the first core 20a and the second core 20b. The refractive index of the first cladding and the second cladding is lower than the refractive index of the first core 20a and the second core 20b. In addition, the second cladding may be omitted so that the refractive index of the first core 20a is higher than the refractive index of the second core 20b.

[0034] 〔Exit head〕

[0035] The output head 25 irradiates the laser beam LB guided by the optical fiber 20 toward a workpiece (not shown).

[0036] 〔Laser device〕

[0037] In this example, the laser device 10 includes a laser oscillator 11 , an operation unit 12 , a display unit 13 , and a control unit 14 .

[0038] 〔Laser oscillator〕

[0039] The laser oscillator 11 irradiates the laser beam LB to the end of the optical fiber 20 as the irradiation object connected to the laser oscillator 11. The laser oscillator 11 includes a housing 11a, a plurality of laser modules 11b, a coupling unit 11c, and a focusing unit 11d. In this example, the laser oscillator 11 is a DDL (Direct Diode Laser) oscillator.

[0040] The housing 11a accommodates a plurality of laser modules 11b, a coupling unit 11c, and a focusing unit 11d. The plurality of laser modules 11b emit lasers respectively. For example, the laser module 11b has a laser array including a plurality of laser diodes (not shown) that emit laser beams of different wavelengths. Furthermore, the laser module 11b performs wavelength synthesis on the laser beams emitted from the plurality of laser diodes, and emits the wavelength synthesized laser beam as a laser. In addition, the output of the laser module 11b may also be variable. The output control of the laser module 11b may also be performed by the control unit 14.

[0041] like Figure 2 As shown, the laser oscillator 11 includes a laser source 101, an optical system 102, a contour detection unit 103, a shutter 104, and a beam damper 105. The laser source 101 is provided in a coupling unit 11c. In this example, the laser source 101 is a coupler for coupling lasers emitted from a plurality of laser modules 11b. The optical system 102 is provided in the coupling unit 11c and the focusing unit 11d. The contour detection unit 103, the shutter 104, and the beam damper 105 are provided in the focusing unit 11d.

[0042] 〔Laser source〕

[0043] The laser source 101 emits laser light LB. The laser source 101 acts as a coupler to couple the laser light emitted from the plurality of laser modules 11b and emits the coupled laser light as laser light LB. For example, the laser source 101 as a coupler includes a plurality of optical components such as a reflector, a lens, and a beam splitter. In addition, the output of the laser source 101 may also be variable. The output control of the laser source 101 may also be performed by the control unit 14.

[0044] The laser source 101 is a coupler, but may be configured as an excitation unit including a plurality of laser modules 11b. Thus, the laser source 101 as an excitation unit couples laser beams emitted from a plurality of laser modules 11b and emits the coupled laser beams as laser beam LB.

[0045] 〔Optical system〕

[0046] The optical system 102 is configured to irradiate the laser light LB emitted from the laser light source 101 to the end of the optical fiber 20 as the irradiation target. The optical system 102 can change the beam profile of the laser light LB irradiated to the irradiation target.

[0047] In this example, the optical system 102 includes a first folding mirror 200, a second folding mirror 300, and a condensing lens 400. The first folding mirror 200 and the second folding mirror 300 are provided in the coupling unit 11c, and the condensing lens 400 is provided in the condensing unit 11d.

[0048] The following will be Figure 2 Set the direction perpendicular to the paper plane as "X-axis direction" and Figure 2 The left-right direction in the paper is set as the "Y-axis direction" which is orthogonal to the X-axis direction. Figure 2 The vertical direction in the paper is set as the "Z-axis direction" which is orthogonal to both the X-axis direction and the Y-axis direction. The focusing lens 400, the partial reflection mirror 500 and the shutter 104 in the closed state are arranged in a straight line in the Z-axis direction between the second folding mirror 300 and the end of the optical fiber 20.

[0049] <1st folding mirror>

[0050] The first folding mirror 200 guides the laser light LB emitted from the laser light source 101 to the second folding mirror 300 by reflecting the laser light LB emitted from the laser light source 101 in a direction different from the traveling direction of the emission.

[0051] <Second folding mirror>

[0052] The second folding mirror 300 guides the laser light LB to the end of the optical fiber 20 by reflecting the laser light LB reflected by the first folding mirror 200 in a direction different from the traveling direction of the laser light LB reflected by the first folding mirror 200 .

[0053] In this example, the second return mirror 300 can be shaken so that the inclination angle of the reflection surface of the second return mirror 300 relative to the optical path of the laser LB incident on the reflection surface of the second return mirror 300 changes. Specifically, the coupling unit 11c has a reflector drive mechanism 350 that drives the second return mirror 300. The reflector drive mechanism 350 shakes the second return mirror 300 around a predetermined swing axis so that the inclination angle of the reflection surface of the second return mirror 300 changes. In this example, the direction of the swing axis of the second return mirror 300 is the X-axis direction. The traveling direction of the laser LB incident on the second return mirror 300 is the Y-axis direction. The direction from the second return mirror 300 toward the end of the optical fiber 20 is the Z-axis direction. In addition, the swing control of the second return mirror 300 (specifically, the control of the reflector drive mechanism 350) is performed by the control unit 14.

[0054] The reflector drive mechanism 350 has a piezoelectric stage and a piezoelectric actuator. A second folding mirror is mounted on the piezoelectric stage. The piezoelectric actuator is mounted on the piezoelectric stage. When the piezoelectric actuator is driven, the swing angle of the piezoelectric stage and the second folding mirror 300 changes, and as a result, the inclination angle of the reflecting surface relative to the optical path of the laser LB incident on the second folding mirror 300 changes, and the position of the spot of the laser LB irradiated to the end of the optical fiber 20 by the laser LB changes.

[0055] <Focusing lens>

[0056] The focusing lens 400 is arranged in the optical path of the laser LB from the second folding mirror 300 toward the end of the optical fiber 20 and focuses the laser LB. In this example, the focusing lens 400 focuses the laser LB so that the diameter of the spot of the laser LB at the end of the optical fiber 20 is smaller than the diameter of the first core 20a of the optical fiber 20.

[0057] In this example, the condenser lens 400 can move in the X-axis direction, the Y-axis direction, and the Z-axis direction. Specifically, the condenser unit 11d has a lens driving mechanism 450. The lens driving mechanism 450 supports the condenser lens 400 and moves the condenser lens 400 in the X-axis direction, the Y-axis direction, and the Z-axis direction. In addition, the position control of the condenser lens 400 (specifically, the control of the lens driving mechanism 450) is performed by the control unit 14.

[0058] 〔Contour detection unit〕

[0059] The profile detection unit 103 detects the beam profile of the laser light LB irradiated from the optical system 102 to the optical fiber 20. In this example, the beam profile detected by the profile detection unit 103 includes information on the position of the spot of the laser light LB at the end of the optical fiber 20. The profile detection unit 103 includes a partial reflector 500 and a partial light receiver 600.

[0060] <Partial Reflector>

[0061] The partial reflection mirror 500 reflects a portion of the laser light LB directed from the condenser lens 400 toward the end of the optical fiber 20. In addition, the remaining portion of the laser light LB directed from the condenser lens 400 toward the end of the optical fiber 20 is transmitted through the partial reflection mirror 500. For example, 0.01% of the laser light LB directed from the condenser lens 400 toward the end of the optical fiber 20 is reflected by the partial reflection mirror 500, and 99.99% of the laser light LB directed from the condenser lens 400 toward the end of the optical fiber 20 is transmitted through the partial reflection mirror 500.

[0062] <Partial light receiver>

[0063] The partial light receiver 600 receives a portion of the laser light LB (hereinafter referred to as "partial light LBa") reflected by the partial reflector 500 of a portion of the laser light LB from the condenser lens 400 toward the end of the optical fiber 20. In addition, the partial light receiver 600 outputs an electrical signal corresponding to the light receiving state (light receiving position and light receiving intensity) of the partial light LBa. The output of the partial light receiver 600 is sent to the control unit 14.

[0064] In this example, the partial light receiver 600 has a light receiving surface 601 for receiving the partial light LBa. The light receiving surface 601 is divided into a plurality of unit areas arranged in a matrix. The partial light receiver 600 outputs an electrical signal corresponding to the light intensity of the partial light LBa in each unit area of ​​the light receiving surface 601.

[0065] Specifically, the partial light receiver 600 has a light receiving surface 601 and a plurality of light receiving elements (not shown). The plurality of light receiving elements are arranged in a matrix on the light receiving surface 601. In other words, the plurality of light receiving elements of the partial light receiver 600 are respectively arranged in a plurality of unit areas of the light receiving surface 601. The outputs of the plurality of light receiving elements of the partial light receiver 600 are sent to the control unit 14.

[0066] 〔shutter〕

[0067] The shutter 104 can be switched between an open state and a closed state. In the open state, the shutter 104 allows the laser LB from the second folding mirror 300 toward the end of the optical fiber 20 (in this example, the laser LB from the second folding mirror 300 toward the end of the optical fiber 20 via the focusing lens 400 and the partial reflection mirror 500) to be incident on the end of the optical fiber 20. In the closed state, the shutter 104 prohibits the laser LB from the second folding mirror 300 toward the end of the optical fiber 20 from being incident on the end of the optical fiber 20.

[0068] In this example, the shutter 104 is movable in the Y-axis direction and can be configured in an open position ( Figure 2The solid line position) and the closed position ( Figure 2 The open position is a position deviated from the optical path of the laser light LB toward the end of the optical fiber 20. The closed position is a position existing in the optical path of the laser light LB toward the end of the optical fiber 20. If the shutter 104 is configured in the open position, the laser light LB toward the end of the optical fiber 20 is incident on the end of the optical fiber 20. If the shutter 104 is configured in the closed position, the shutter 104 reflects the laser light LB toward the end of the optical fiber 20 toward the beam damper 105.

[0069] Specifically, the focusing unit 11d includes a shutter drive mechanism 106. The shutter drive mechanism 106 supports the shutter 104 and moves the shutter 104 in the Y-axis direction. The control unit 14 controls the opening and closing of the shutter 104 (specifically, controls the shutter drive mechanism 106).

[0070] 〔Beam Damper〕

[0071] The beam damper 105 receives the laser light LB reflected by the shutter 104 in the closed state, and consumes the laser light LB by converting the laser light LB into heat.

[0072] [Operation and display]

[0073] The operation unit 12 is assigned an operation based on the operator, and outputs a signal corresponding to the operation assigned by the operator. With such a structure, the operator can operate the operation unit 12 to input information. The output of the operation unit 12 is sent to the control unit 14. For example, the operation unit 12 can be an operation button pressed by the operator, or an operation unit of a touch panel. The display unit 13 displays information. For example, the display unit 13 can also be a display unit of a touch panel.

[0074] 〔Control Department〕

[0075] The control unit 14 is electrically connected to each part of the laser device 10, and can transmit signals between each part of the laser device 10. In this example, the control unit 14 is electrically connected to each part of the laser oscillator 11 (such as the laser source 101, etc.), the operation unit 12, and the display unit 13. In addition, the control unit 14 controls each part of the laser device 10. For example, the control unit 14 performs swing control of the second folding mirror 300, position control of the focusing lens 400, opening and closing control of the shutter 104, etc. In addition, in this example, the control unit 14 is electrically connected to each part of the laser processing system 1 (such as the output head 25, etc.), and controls each part of the laser processing system 1. For example, the control unit 14 includes a processor and a memory for storing programs and information for causing the processor to operate. The operation of the control unit 14 will be described in detail later.

[0076] [Relationship between the incident state of laser light, the incident state of partial light, and the beam profile]

[0077] Figure 3 The relationship between the incident state of the laser light LB, the incident state of the partial light LBa and the beam profile of the laser light LB is exemplified. The light receiving surface 601 of the partial light receiver 600 has a first region 611 corresponding to the first core 20a of the optical fiber 20 and a second region 612 corresponding to the second core 20b of the optical fiber 20.

[0078] like Figure 3 As shown, according to the change in the incident state of the laser LB at the end of the optical fiber 20, that is, the state (position and diameter (shape)) of the spot, the incident state of the partial light LBa received by the light receiving surface 601 of the partial light receiver 600 changes, and the beam profile of the laser LB (for example, the beam profile of the laser LB emitted from the output head 25 via the optical fiber 20) changes. In addition, regarding the change in the beam profile of the laser LB corresponding to the change in the incident state of the laser LB, that is, the position of the spot, there is a tendency that the position of the laser LB changes more significantly when the boundary position of the first core 20a and the second core 20b changes than when the position of the laser LB spot changes in the first core 20a or the second core 20b.

[0079] In addition, if Figure 3 As shown, the incident state (position and diameter) of the spot of the partial light LBa at the light receiving surface 601 of the partial light receiver 600 corresponds to the incident state (position and diameter) of the spot of the laser LB at the end of the optical fiber 20. According to the change of the position (or diameter) of the spot of the laser LB at the end of the optical fiber 20, the position (or diameter) of the spot of the partial light LBa at the light receiving surface 601 of the partial light receiver 600 changes.

[0080] For example, when the spot of the laser light LB is located at the first core 20a (or the second core 20b) of the optical fiber 20, the spot of the partial light LBa is located at the first region 611 (or the second region 612) of the light receiving surface 601 of the partial light receiver 600. In addition, when the spot of the laser light LB is located at the boundary between the first core 20a and the second core 20b of the optical fiber 20, the spot of the partial light LBa is located at the boundary between the first region 611 and the second region 612 of the light receiving surface 601 of the partial light receiver 600. If the diameter of the spot of the laser light LB increases, the diameter of the spot of the partial light LBa also increases.

[0081] As described above, the state (position and diameter) of the spot of the partial light LBa at the light receiving surface 601 of the partial light receiver 600 corresponds to the state (position and diameter) of the spot of the laser LB at the end of the optical fiber 20. Therefore, by detecting the state (position and diameter) of the spot of the partial light LBa at the light receiving surface 601 of the partial light receiver 600, the state (position and diameter) of the spot of the laser LB at the end of the optical fiber 20 can be detected, and as a result, the beam profile of the laser LB can be detected.

[0082] [Goal Setting]

[0083] In the laser device 10, when processing a workpiece using the laser LB, a desired beam profile (target beam profile) is set. The desired beam profile is set according to the irradiation conditions of the laser LB. For example, the desired beam profile is set according to the thickness of the workpiece to be cut by the laser LB.

[0084] If the desired beam profile is set by the operation unit 12, the control unit 14 sets the target spot position and the target spot diameter according to the desired beam profile. The target spot position and the target spot diameter are the target position and the target diameter of the spot of the laser light LB at the end of the optical fiber 20. The target spot position and the target spot diameter are set to the position and the diameter of the laser light LB at the end of the optical fiber 20 corresponding to the desired beam profile.

[0085] For example, Figure 3 As shown in (A), by setting the target spot position to the position of the first core 20a, the beam profile of the laser LB can be set to a beam profile suitable for cutting a thin plate (for example, a plate with a thickness of 1 to 3 mm). Figure 3 As shown in (B), by setting the target spot position to a position that spans both the end face of the first core 20a and the end face of the second core 20b, the beam profile of the laser LB can be set to a beam profile suitable for cutting a medium-thick plate (for example, a plate with a thickness of 4 to 16 mm). Figure 3 As shown in (C), by setting the target spot position to the position of the second core 20b, the beam profile of the laser LB can be set to a beam profile suitable for cutting a thick plate (for example, a plate with a thickness of 18 to 25 mm). The target spot diameter is set to a smaller diameter than the first core 20a, for example.

[0086] In this example, the control unit 14 sets the target partial spot position and the target partial spot diameter according to the desired beam profile. The target partial spot position and the target partial spot diameter correspond to the target position and the target diameter of the spot of the partial light LBa at the light receiving surface 601 of the partial light receiver 600. The target partial spot position and the target partial spot diameter are set to the position and diameter corresponding to the desired beam profile.

[0087] Furthermore, the control unit 14 controls the optical system 102 to change the state (position and diameter) of the spot of the laser light LB at the end of the optical fiber 20 so that the beam profile (the spot position and the spot diameter of the spot of the partial light LBa at the light receiving surface 601 of the partial light receiver 600 corresponding to the beam profile) detected by the profile detection unit 103 for detecting the state (position and diameter) of the spot of the laser light LB at the end of the optical fiber 20 becomes the desired beam profile (the spot position and the spot diameter of the spot of the partial light LBa at the light receiving surface 601 of the partial light receiver 600 corresponding to the beam profile) Figure 3 The target spot position and target spot diameter of the partial light LBa at the light receiving surface 601 of the partial light receiver 600 correspond to the target position of the spot of the laser LB at the end of the optical fiber 20 and the target spot profile shown in A, B, and C).

[0088] [Deviation of the optical path of an optical system]

[0089] If the optical path of the optical system 102 deviates, the beam profile of the laser light LB changes. For example, if the optical path of the optical system 102 deviates due to heat such as the thermal lens effect of the optical components constituting the optical system 102 or the deformation caused by the heat of the housing 11a, the position of the spot of the laser light LB at the end of the optical fiber 20 deviates, resulting in a change in the beam profile of the laser light LB.

[0090] 〔Control Process〕

[0091] The control unit 14 performs control processing according to each pre-set control cycle. In the control processing, the control unit 14 controls the optical system 102 so that the beam profile detected by the profile detection unit 103 becomes the desired beam profile. In this example, the profile detection unit 103 detects the state (position and diameter) of the spot of the laser LB at the end of the optical fiber 20. The control unit 14 controls the optical system 102 so that the position of the spot of the laser LB detected by the profile detection unit 103 becomes the pre-set target spot position. For example, the control cycle is a cycle of microseconds.

[0092] Next, refer to Figure 4 Next, the control process of the control unit 14 according to Embodiment 1 will be described. The control unit 14 performs the following process in each preset control cycle.

[0093] <Step S11>

[0094] In step S11, the control unit 14 determines whether the beam profile detected by the profile detection unit 103 (hereinafter referred to as "detected beam profile") is a desired beam profile. If the detected beam profile is not the desired beam profile, the process of step S12 is performed, and if the detected beam profile is the desired beam profile, the control process ends.

[0095] In this example, when the difference between the detected beam profile and the desired beam profile is smaller than a preset profile allowable difference, the control unit 14 determines that the detected beam profile is the desired beam profile.

[0096] Specifically, the control unit 14 determines that the detected light beam profile is the desired light beam profile when the difference between the position of the light spot of the partial light LBa detected by the contour detection unit 103 and the position of the target light spot is lower than a preset position allowable difference, and the difference between the diameter of the light spot of the partial light LBa detected by the contour detection unit 103 and the diameter of the target light spot is lower than a preset diameter allowable difference.

[0097] <Step S12>

[0098] If the detected beam profile is not a desired beam profile in step S11 , the control unit 14 controls the optical system 102 in step S12 so that the detected beam profile becomes a desired beam profile.

[0099] In addition, in this example, the control unit 14 can change the position of the laser LB spot at the end of the optical fiber 20 in the Y-axis direction by changing the swing angle of the second return mirror 300 in the optical system 102. In addition, by changing the position of the focusing lens 400 in the X-axis direction, the position of the laser LB spot at the end of the optical fiber 20 can be changed in the X-axis direction. By changing the position of the focusing lens 400 in the Y-axis direction, the position of the laser LB spot at the end of the optical fiber 20 can be changed in the Y-axis direction. By changing the position of the focusing lens 400 in the Z-axis direction, the diameter of the laser LB spot at the end of the optical fiber 20 can be changed.

[0100] In addition, the change in the position of the spot of the laser LB at the end of the optical fiber 20 is first adjusted by adjusting the position of the focusing lens 400 so that the spot diameter of the laser LB is smaller than the diameter of the first core 20a of the optical fiber 20, and the center of the optical axis of the spot diameter of the laser LB is brought to the center of the diameter of the first core 20a, and then the swing angle of the second return mirror 300 is changed so that the position is changed from the first core 20a to the second core 20b of the optical fiber 20. By setting the swing angle change of the second return mirror 300 to a single-axis direction, the structure of the reflector drive mechanism 350 that drives the second return mirror 300 can be made simple and compact.

[0101] Furthermore, the position of the condenser lens 400 may be finely adjusted after changing the swing angle of the second folding mirror 300. This makes it possible to easily perform fine position adjustment.

[0102] In addition, by changing the swing angle of the second return mirror 300, the position of the spot of the laser LB at the end of the optical fiber 20 is set to a single-axis direction and changed in the Y-axis direction, but it can also be set to a structure in which the swing angle of the second return mirror 300 is changed in two-axis directions and the position of the spot of the laser LB at the end of the optical fiber 20 is changed in the X-axis direction and the Y-axis direction. In addition, the change of the position of the spot of the laser LB at the end of the optical fiber 20 can also be performed by changing the swing angle of the second return mirror 300 without adjusting the position of the focusing lens 400.

[0103] The control unit 14 controls the swing angle of the second folding mirror 300 and / or the position of the focusing lens 400 so that the state (position and diameter) of the spot of the partial light LBa at the light receiving surface 601 of the partial light receiver 600 becomes a predetermined target state (target partial spot position and target partial spot diameter).

[0104] Specifically, the control unit 14 controls the swing angle of the second returning mirror 300 in the optical system 102 and / or the position of the focusing lens 400 so that the difference between the position of the spot of the partial light LBa and the position of the target partial spot is close to zero, or the difference between the position of the spot of the partial light LBa and the position of the target partial spot is within a preset allowable difference, and controls the position of the focusing lens 400 in the Z-axis direction so that the difference between the diameter of the spot of the partial light LBa and the diameter of the target partial spot is close to zero, or the difference between the diameter of the spot of the partial light LBa and the diameter of the target partial spot is within a preset allowable difference.

[0105] By making the state of the spot of partial light LBa at the light receiving surface 601 of the partial light receiver 600 close to the target state, the state (position and diameter) of the spot of laser LB at the end of the optical fiber 20 can be made close to the target state (target spot position and target spot diameter). As a result, the beam profile of laser LB can be made close to the desired beam profile.

[0106] [Effects of Embodiment 1]

[0107] As described above, the control unit 14 controls the optical system 102 at each preset control cycle so that the beam profile detected by the profile detection unit 103 becomes a desired beam profile. This can suppress changes in the beam profile of the laser light caused by deviation of the optical path of the optical system 102.

[0108] (Implementation Method 2)

[0109] The operation of the control unit 14 of the laser device 10 of the second embodiment is different from that of the laser device 10 of the first embodiment. The other structures of the laser device 10 of the second embodiment are the same as those of the laser device 10 of the first embodiment.

[0110] In the second embodiment, the control unit 14 performs abnormal difference notification in the control process. In the abnormal difference notification, when the difference between the position of the spot of the laser LB at the end of the optical fiber 20 detected by the contour detection unit 103 (hereinafter referred to as "detected spot position") and the target spot position exceeds a preset allowable difference, the control unit 14 outputs abnormal difference notification information for notifying the abnormality of the difference. For example, the allowable difference is set to a difference smaller than the abnormal difference at which the difference between the detected spot position and the target spot position is considered abnormal.

[0111] 〔Control Process〕

[0112] Next, refer to Figure 5 Next, the control process of the control unit 14 according to Embodiment 2 will be described. The control unit 14 performs the following process in each preset control cycle.

[0113] <Step S20>

[0114] In step S20, the control unit 14 determines whether the detected beam profile (the beam profile detected by the profile detection unit 103) is a desired beam profile. If the detected beam profile is not a desired beam profile, the process of step S21 is performed. If the detected beam profile is a desired beam profile, the control process ends.

[0115] <Step S21>

[0116] In step S20, when the detected beam profile is not the desired beam profile, the control unit 14 determines in step S21 whether the difference between the detected spot position (the position of the spot of the laser light LB at the end of the optical fiber 20 detected by the profile detection unit 103) and the target spot position is an abnormal difference exceeding the allowable difference. If the difference between the detected spot position and the target spot position is an abnormal difference exceeding the allowable difference, the process of step S22 is performed, and if not, the process of step S23 is performed.

[0117] <Step S22>

[0118] In step 21, when the difference between the detection spot position and the target spot position is an abnormal difference exceeding the allowable difference, the control unit 14 outputs abnormal difference notification information for notifying that the difference between the detection spot position and the target spot position is abnormal in step 22. For example, the control unit 14 outputs the abnormal difference notification information to the display unit 13. Thus, the abnormal difference notification information is displayed on the display unit 13, and the difference between the detection spot position and the target spot position is normal.

[0119] <Step S23>

[0120] On the other hand, in step S21 , when the difference between the detection spot position and the target spot position is not an abnormal difference that does not exceed the allowable difference, the control unit 14 controls the optical system 102 in step S23 so that the detection beam profile becomes a desired beam profile.

[0121] [Effects of Embodiment 2]

[0122] In the second embodiment, the same effects as those of the first embodiment can be obtained.

[0123] In the second embodiment, when the difference between the spot position of the laser light LB and the target spot position is normal, the abnormal difference notification information can be output to notify that the difference between the spot position of the laser light LB and the target spot position is normal.

[0124] (Variation 1 of Implementation Method 2)

[0125] The operation of the control unit 14 of the laser device 10 of the first modification of the second embodiment is different from that of the laser device 10 of the second embodiment. The other configurations of the laser device 10 of the first modification of the second embodiment are the same as those of the laser device 10 of the second embodiment.

[0126] In the first variant of the second embodiment, the control unit 14 performs a notification of inability to control during the control process. In the notification of inability to control, the control unit 14 outputs inability to control notification information for notifying that control is inability to control when the beam profile detected by the profile detection unit 103 cannot be set to a desired beam profile even if the optical system 102 is controlled. For example, when the position of the spot of the laser LB at the end of the optical fiber 20 is switched from the first core 20a of the optical fiber 20 to the second core 20b, even if the optical system 102 is controlled to set the beam profile detected by the profile detection unit 103 to a desired beam profile, the position cannot be clearly switched because the difference between the position of the spot of the laser LB and the target spot position exceeds the range of abnormal difference, etc., and the optical components constituting the optical system 102 are in an inability to control state, such as a poor control condition.

[0127] 〔Control Process〕

[0128] Next, refer to Figure 6 The control process of the control unit 14 according to the first modification of the second embodiment will be described. In the control process of the first modification of the second embodiment, steps S24 to S26 below are performed instead of steps S21 to S23 of the control process of the second embodiment.

[0129] <Step S24>

[0130] In step S20, when the detected beam profile (the beam profile detected by the profile detection unit 103) is not the desired beam profile, the control unit 14 determines in step S24 whether the optical system 102 cannot be controlled so that the detected beam profile becomes the desired beam profile. If the optical system 102 cannot be controlled so that the detected beam profile becomes the desired beam profile, the process of step S25 is performed, and if not, the process of step S26 is performed.

[0131] <Step S25>

[0132] In step S24, when the optical system 102 cannot be controlled so that the detection beam profile becomes the desired beam profile, the control unit 14 outputs, in step S25, control failure notification information for notifying that the optical system 102 cannot be controlled so that the detection beam profile becomes the desired beam profile. For example, the control unit 14 outputs the control failure notification information to the display unit 13. Thus, the control failure notification information is displayed on the display unit 13, and the situation that the optical system 102 cannot be controlled so that the detection beam profile becomes the desired beam profile is notified.

[0133] <Step S26>

[0134] On the other hand, when the optical system 102 can be controlled so that the detection beam profile becomes the desired beam profile in step S24 , the control unit 14 controls the optical system 102 so that the detection beam profile becomes the desired beam profile in step S26 .

[0135] [Effects of Modification 1 of Implementation Method 2]

[0136] In the first modification of the second embodiment, the same effects as those of the first embodiment can be obtained.

[0137] In the first variation of the second embodiment, when the optical system 102 cannot be controlled to set the beam profile to a desired beam profile, the control failure notification information can be output to notify that the optical system 102 cannot be controlled to set the beam profile to a desired beam profile.

[0138] (Variation 2 of Implementation Example 2)

[0139] The operation of the control unit 14 of the laser device 10 of the second modification of the second embodiment is different from that of the laser device 10 of the second embodiment. The other configurations of the laser device 10 of the second modification of the second embodiment are the same as those of the laser device 10 of the second embodiment.

[0140] In the second modification of the second embodiment, the control unit 14 performs correction abnormality notification during the control process. In the correction abnormality notification, the control unit 14 outputs correction abnormality notification information for notifying the correction abnormality when the beam profile detected by the profile detection unit 103 is not the desired beam profile and the number of corrections by the optical system 102 of the control unit 14 exceeds a preset threshold. For example, the threshold is set to a number smaller than the number of corrections (number of abnormalities) when the correction by the optical system 102 of the control unit 14 cannot be performed normally.

[0141] 〔Control Process〕

[0142] Next, refer to Figure 7 , the control process of the control unit 14 based on the second modification of the second embodiment is described. In the control process of the second modification of the second embodiment, steps S27 to S29 are performed instead of steps S21 to S23 of the control process of the second embodiment. In addition, the control unit 14 counts the number of corrections. For example, the number of corrections is stored in a memory (not shown).

[0143] <Step S27>

[0144] In step S20, when the detected beam profile (the beam profile detected by the profile detection unit 103) is not the desired beam profile, the control unit 14 determines in step S27 whether it is a correction abnormality in which the number of corrections of the optical system 102 by the control unit 14 exceeds the threshold. If the number of corrections of the optical system 102 by the control unit 14 exceeds the threshold, the process of step S28 is performed, and if not, the process of step S29 is performed.

[0145] <Step S28>

[0146] In step S27, if the correction number of the optical system 102 by the control unit 14 exceeds the threshold value, the control unit 14 outputs correction abnormality notification information for notifying that the correction of the optical system 102 by the control unit 14 cannot be performed normally in step S28. For example, the control unit 14 outputs the correction abnormality notification information to the display unit 13. Thus, the correction abnormality notification information is displayed on the display unit 13, notifying that the correction of the optical system 102 by the control unit 14 cannot be performed normally.

[0147] <Step S29>

[0148] On the other hand, in step S27, if the correction number of the optical system 102 by the control unit 14 does not exceed the threshold value, the control unit 14 controls the optical system 102 in step S29 so that the detected beam profile becomes a desired beam profile. The control unit 14 adds 1 to the correction number.

[0149] Furthermore, when the control unit 14 determines in step S20 that the detected beam profile is a desired beam profile, the control unit 14 resets the number of corrections to zero.

[0150] [Effects of Variation 2 of Implementation Method 2]

[0151] In the second modification of the second embodiment, the same effects as those of the first embodiment can be obtained.

[0152] Furthermore, in the second modification of the second embodiment, in the case of a correction abnormality of the optical system 102 by the control unit 14 , the correction abnormality of the optical system 102 by the control unit 14 can be notified by outputting correction abnormality notification information.

[0153] (Implementation 3)

[0154] When the target spot position is set at the boundary position between the first core 20a and the second core 20b of the optical fiber 20, in other words, when the spot diameter of the target spot position is set to straddle the boundary position between the first core 20a and the second core 20b of the optical fiber 20, the spot position of the laser LB changes at the boundary position between the first core 20a and the second core 20b of the optical fiber 20. Therefore, at the boundary position between the first core 20a and the second core 20b of the optical fiber 20, the change in the beam profile of the laser LB corresponding to the change in the spot position of the laser LB becomes significant (sensitive) due to the change in the ratio of the spot diameter of the target spot position applied to the first core 20a and the second core 20b of the optical fiber 20. In this case, in order to increase the execution frequency of the control processing (processing for making the beam profile of the laser LB close to the desired beam profile) by the control unit 14, it is preferable to set the control cycle (cycle in which the control processing is executed) to a short cycle.

[0155] In addition, when the target spot position is set to the first core 20a (or the second core 20b) of the optical fiber 20, in other words, when the spot diameter of the target spot position is set to be within the first core 20a (or the second core 20b) of the optical fiber 20, the position of the spot of the laser LB changes within the first core 20a (or the second core 20b) of the optical fiber 20. Therefore, the change of the beam profile of the laser LB corresponding to the change of the position of the spot of the laser LB becomes stable (insensitive). In this case, in order to reduce the execution frequency of the control processing based on the control unit 14, it is preferable to set the control cycle to a long cycle.

[0156] 〔Laser device〕

[0157] The operation of the control unit 14 of the laser device 10 of the third embodiment is different from that of the laser device 10 of the first embodiment. The other structures of the laser device 10 of the third embodiment are the same as those of the laser device 10 of the first embodiment.

[0158] In Embodiment 3, the control unit 14 performs the adjustment process of the determination process at each predetermined adjustment cycle (sampling cycle) that is set in advance. For example, in the adjustment process, the control unit 14 changes the control cycle according to the target spot position.

[0159] In the third embodiment, the control unit 14 performs the control process for each control cycle adjusted (changed) by the adjustment process. The control process of the third embodiment is the same as the control process of the first embodiment.

[0160] 〔Adjustment Process〕

[0161] Next, refer to Figure 8Next, the adjustment process of the control unit 14 according to Embodiment 3 is described. The control unit 14 performs the following process at each predetermined adjustment period (sampling period) set in advance.

[0162] <Step S31>

[0163] In step S31, the control unit 14 determines whether the target spot position is set at a boundary position (a position that crosses the first core 20a and the second core 20b of the optical fiber 20, i.e., the boundary position; in other words, a position where the spot diameter of the target spot position crosses the boundary position between the first core 20a and the second core 20b of the optical fiber 20, i.e., the boundary position). If the target spot position is set at the boundary position, the process of step S32 is performed, and if not, the process of step S33 is performed.

[0164] <Step S32>

[0165] In step S31, when the target spot position is set at the boundary position, in other words, when the spot diameter of the target spot position is set to the boundary position spanning the first core 20a and the second core 20b of the optical fiber 20, the control unit 14 sets the control period to the first period in step S32.

[0166] <Step S33>

[0167] On the other hand, in step S31, when the target spot position is not set at the boundary position, in other words, when the spot diameter of the target spot position is set to be within the first core 20a (or the second core 20b) of the optical fiber 20, the control unit 14 sets the control period to a second period that is longer than the first period in step S33.

[0168] [Effects of Implementation Method 3]

[0169] In the third embodiment, the same effects as those of the first embodiment can be obtained.

[0170] Furthermore, in the third embodiment, by changing the control period according to the target spot position, the control period can be appropriately set to a period corresponding to the target spot position.

[0171] In addition, in Embodiment 3, the target position and target diameter of the spot of the laser LB at the end of the optical fiber 20, i.e., the target spot position, may be replaced by the position of the spot of the laser LB detected by the contour detection unit 103, i.e., the detection spot position. Furthermore, in step S31, it is determined whether the target spot position (the position spanning the first core 20a and the second core 20b of the optical fiber 20, i.e., the boundary position) is the boundary position, or it may be replaced by determining whether the detection spot position is the boundary position (the position spanning the first core 20a and the second core 20b of the optical fiber 20, i.e., the boundary position). Thus, by changing the control period according to the detection spot position, the control period can be appropriately set to a period corresponding to the detection spot position.

[0172] (Implementation 4)

[0173] When the beam profile of laser LB is unstable, in order to increase the execution frequency of the control processing (processing for making the beam profile of laser LB close to the desired beam profile) by the control unit 14, it is preferable to set the control cycle (the cycle in which the control processing is executed) to a short cycle.

[0174] Furthermore, when the beam profile of the laser light LB is stable, it is preferable to set the control cycle to a long cycle in order to reduce the execution frequency of the control process by the control unit 14 .

[0175] 〔Laser device〕

[0176] The operation of the control unit 14 of the laser device 10 of the fourth embodiment is different from that of the laser device 10 of the first embodiment. The other structures of the laser device 10 of the fourth embodiment are the same as those of the laser device 10 of the first embodiment.

[0177] In Embodiment 4, the control unit 14 performs an adjustment process of the judgment process at each predetermined adjustment cycle (sampling cycle). In the adjustment process, the control unit 14 changes the control cycle according to the stability of the beam profile detected by the profile detection unit 103. For example, when the change of the beam profile detected by the profile detection unit 103 (specifically, the change of the position of the spot of the laser LB at the end of the optical fiber 20, in other words, the change of the difference between the detected spot position and the target spot position of the laser LB at each control cycle or the timing of switching the position of the spot of the laser LB at the end of the optical fiber 20) is within a predetermined allowable range and the duration exceeds a predetermined stabilization time, the control unit 14 determines that the beam profile is stable. The allowable range is set to a range in which the change of the beam profile is considered to be stable. The stabilization time is set to a time in which the change of the beam profile is considered to be stable.

[0178] In the fourth embodiment, the control unit 14 performs the control process for each control cycle adjusted (changed) by the adjustment process. The control process of the fourth embodiment is the same as the control process of the first embodiment.

[0179] 〔Adjustment Process〕

[0180] Next, refer to Fig.10 The following specifically describes the adjustment process of the control unit 14 according to Embodiment 4. The control unit 14 performs the following process at each predetermined adjustment period (sampling period) set in advance.

[0181] <Step S41>

[0182] In step S41, the control unit 14 determines whether the beam profile detected by the profile detection unit 103 is unstable, in other words, whether the variation of the beam profile is unstable. If the beam profile is unstable, the process of step S42 is performed, and if not, the process of step S43 is performed.

[0183] <Step S42>

[0184] In step S42 , when the beam profile is unstable, the control unit 14 sets the control cycle to the first cycle.

[0185] <Step S43>

[0186] On the other hand, when the beam profile is not unstable but stable in step S41 , the control unit 14 sets the control cycle to a second cycle longer than the first cycle in step S43 .

[0187] [Effects of Implementation Method 4]

[0188] In the fourth embodiment, the same effects as those of the first embodiment can be obtained.

[0189] Furthermore, in the fourth embodiment, by changing the control period according to the stability of the beam profile, the control period can be appropriately set to a period according to the stability of the beam profile.

[0190] (Implementation method 5)

[0191] If the ambient temperature of the optical system 102 changes, the deviation of the optical path of the optical system 102 changes, the position of the spot of the laser light LB at the end of the optical fiber 20 changes, and as a result, the beam profile of the laser light LB changes. In addition, when the driving of the laser oscillator 11 (specifically, the laser module 11b and the laser source 101) starts, specifically, when it is started for the first time of the day or restarted after being stopped for several minutes to several hours, the ambient temperature of the optical system 102 gradually rises over time due to the driving heat of the laser oscillator 11, and then the ambient temperature of the optical system 102 becomes steady (thermally stable).

[0192] When the ambient temperature of the optical system 102, which is a temperature related to the optical system 102, is lower than the steady-state temperature and is not thermally stable during the temperature rise, the beam profile of the laser LB is unstable. Therefore, in order to increase the execution frequency of the control processing based on the control unit 14 (processing for making the beam profile of the laser LB close to the desired beam profile), it is advisable to set the control cycle (the cycle in which the control processing is executed) to a short cycle.

[0193] On the other hand, when the ambient temperature of the optical system 102 reaches a steady-state temperature, the beam profile of the laser light LB is stabilized. Therefore, in order to reduce the execution frequency of the control process by the control unit 14, it is preferable to set the control cycle to a long cycle.

[0194] 〔Laser device〕

[0195] Fig.11 The structure of the laser device 10 according to the fifth embodiment is exemplified. The laser device 10 according to the fifth embodiment has Figure 2 The structure of the laser device 10 of the first embodiment shown further includes a temperature detection unit 15. The operation of the control unit 14 of the laser device 10 of the fifth embodiment is different from that of the laser device 10 of the first embodiment. The other structures of the laser device 10 of the fifth embodiment are the same as those of the laser device 10 of the first embodiment.

[0196] The temperature detection unit 15 detects the ambient temperature of the optical system 102, which is a temperature related to the optical system 102. Examples of the ambient temperature of the optical system 102 include the temperature of the laser module 11b, the temperature of the coupling unit 11c, the temperature inside the housing 11a, and the temperature around the laser oscillator 11.

[0197] In Embodiment 5, the control unit 14 performs the adjustment process of the determination process at each predetermined adjustment cycle (sampling cycle) set in advance. In the adjustment process, the control unit 14 changes the control cycle according to the ambient temperature detected by the temperature detection unit 15 .

[0198] In the fifth embodiment, the control unit 14 performs the control process for each control cycle adjusted (changed) by the adjustment process. The control process of the fifth embodiment is the same as the control process of the first embodiment.

[0199] 〔Adjustment Process〕

[0200] Next, refer to Fig.12 The following describes the adjustment process of the control unit 14 according to Embodiment 5. The control unit 14 performs the following process at each predetermined adjustment period (sampling period) set in advance.

[0201] <Step S51>

[0202] In step S51, the control unit 14 determines whether the ambient temperature detected by the temperature detection unit 15 is lower than the reference temperature. When the ambient temperature of the optical system 102 is lower than the reference temperature, the process of step S52 is performed, and when it is not the case, the process of step S53 is performed. For example, the reference temperature is set to the temperature when the ambient temperature of the optical system 102 is in a steady state. Specifically, the reference temperature can also be set to an arbitrary temperature in the temperature range when the ambient temperature of the optical system 102 is in a steady state. Here, the so-called setting to an arbitrary temperature includes the case where the reference temperature is set to the average value of the temperature when the ambient temperature of the optical system 102 is in a steady state, or the lower limit value of the temperature when the ambient temperature of the optical system 102 is in a steady state.

[0203] <Step S52>

[0204] In step S51 , when the ambient temperature of the optical system 102 is lower than the reference temperature, the control unit 14 sets the control cycle to the first cycle in step S52 .

[0205] <Step S53>

[0206] On the other hand, when the ambient temperature of the optical system 102 is equal to or higher than the reference temperature in step S51 , the control unit 14 sets the control cycle to a second cycle that is longer than the first cycle in step S53 .

[0207] [Effects of Implementation Method 5]

[0208] In the fifth embodiment, the same effects as those of the first embodiment can be obtained.

[0209] Furthermore, in Embodiment 5, by changing the control cycle according to the ambient temperature of the optical system 102 , which is a temperature related to the optical system 102 , the control cycle can be set to a cycle corresponding to the ambient temperature of the optical system 102 .

[0210] (Implementation 6)

[0211] When the driving of the laser oscillator 11 (specifically, the laser module 11b and the laser source 101) starts, specifically, the initial start of the day, or restarting after being stopped for several minutes to several hours, the ambient temperature of the optical system 102, which is a temperature related to the optical system 102, gradually rises over time due to the driving heat of the laser oscillator 11, and then the ambient temperature of the optical system 102 becomes steady (thermally stable).

[0212] During the period from when the laser oscillator 11 is driven to when the ambient temperature of the optical system 102 becomes steady, the beam profile of the laser LB is unstable. Therefore, in order to increase the execution frequency of the control processing based on the control unit 14 (processing for making the beam profile of the laser LB close to the desired beam profile), it is advisable to set the control cycle (the cycle in which the control processing is executed) to a short cycle.

[0213] On the other hand, after the ambient temperature of the optical system 102 becomes steady, the beam profile of the laser light LB is stable. Therefore, in order to reduce the execution frequency of the control process by the control unit 14, it is preferable to set the control cycle to a long cycle.

[0214] The time required from the start of driving the laser oscillator 11 until the ambient temperature of the optical system 102 reaches a steady state can be obtained in advance through a test run or the like.

[0215] 〔Laser device〕

[0216] Fig.13 The structure of the laser device 10 according to the sixth embodiment is exemplified. The laser device 10 according to the sixth embodiment has Figure 2 The structure of the laser device 10 of the first embodiment shown further includes a timer 16. The operation of the control unit 14 of the laser device 10 of the sixth embodiment is different from that of the laser device 10 of the first embodiment. The other structures of the laser device 10 of the sixth embodiment are the same as those of the laser device 10 of the first embodiment.

[0217] The timing unit 16 measures the elapsed time from the start of driving of the laser light source 101 .

[0218] In Embodiment 6, the control unit 14 performs the adjustment process of the determination process at each predetermined adjustment cycle (sampling cycle) set in advance. In the adjustment process, the control unit 14 changes the control cycle according to the elapsed time measured by the timing unit 16 .

[0219] In the sixth embodiment, the control unit 14 performs the control process for each control cycle adjusted (changed) by the adjustment process. The control process of the sixth embodiment is the same as the control process of the first embodiment.

[0220] 〔Adjustment Process〕

[0221] Next, refer to Fig.14 The following describes the adjustment process of the control unit 14 according to Embodiment 6. The control unit 14 performs the following process at each predetermined adjustment period (sampling period) set in advance.

[0222] <Step S61>

[0223] In step S61, the control unit 14 determines whether the elapsed time detected by the timing unit 16 is shorter than the reference time. If the elapsed time from the start of the drive of the laser light source 101 is shorter than the reference time, the process of step S62 is performed, and if not, the process of step S63 is performed. For example, the reference time is set to the time required from the start of the drive of the laser light source 101 to the time when the ambient temperature of the optical system 102 becomes stable.

[0224] <Step S62>

[0225] In step S61 , when the elapsed time from the start of driving the laser light source 101 is shorter than the reference time, the control unit 14 sets the control cycle to the first cycle in step S62 .

[0226] <Step S63>

[0227] On the other hand, in step S61, when the elapsed time from the start of driving the laser source 101 is not shorter than the reference time, in other words, when the elapsed time from the start of driving the laser source 101 is greater than the reference time, the control unit 14 sets the control period to the second period longer than the first period in step S63.

[0228] [Effects of Implementation Method 6]

[0229] In the sixth embodiment, the same effects as those of the first embodiment can be obtained.

[0230] Furthermore, in the sixth embodiment, by changing the control cycle according to the elapsed time from the start of driving the laser light source 101 , the control cycle can be appropriately set to a cycle corresponding to the elapsed time from the start of driving the laser light source 101 .

[0231] (Other embodiments)

[0232] In the above description, the mirror driving mechanism 350 is described as including a piezoelectric stage and a piezoelectric actuator, but the present invention is not limited thereto. Fig.14As shown, the reflector drive mechanism 350 may also include a swing motor 351 and an encoder 352. The second return mirror 300 is fixed to the rotation axis of the swing motor 351. The rotation axis of the swing motor 351 constitutes the swing axis of the second return mirror 300. With such a structure, if the swing motor 351 is driven, the swing angle of the second return mirror 300 changes according to the change of the rotation angle of the swing motor 351, and as a result, the inclination angle of the reflecting surface relative to the optical path of the laser LB incident on the second return mirror 300 changes. The encoder 352 detects the rotation angle of the swing motor 351. The output of the encoder 352 is sent to the control unit 14.

[0233] In the above description, the end of the optical fiber 20 is cited as an example of the irradiated object, but the irradiated object is not limited to this.

[0234] In addition, in the above description, the adjustment process of the judgment process is performed at each adjustment cycle (sampling cycle), and the control cycle is changed to the first cycle or the second cycle, but it is not limited to this. The control cycle in the set first cycle or second cycle can also be set as the sampling cycle, and the adjustment process of the judgment process is performed at each sampling cycle in the control cycle, and the control cycle is changed to the first cycle or the second cycle.

[0235] The above embodiments may be appropriately combined and implemented. The above embodiments are essentially preferred examples and are not intended to limit the scope of the invention, its applications, or its uses.

[0236] Industrial Applicability

[0237] As described above, the technology disclosed here is useful as a laser device.

[0238] -Explanation of symbols-

[0239] 1Laser processing system

[0240] 10Laser device

[0241] 11Laser Oscillator

[0242] 12 Operation part

[0243] 13 Display unit

[0244] 14. Control Unit

[0245] 15 Temperature detection unit

[0246] 16 Timing Department

[0247] 20 Fiber

[0248] 20a 1st core

[0249] 20b 2nd core

[0250] 25 output head

[0251] 101 Laser Source

[0252] 102 Optical System

[0253] 103 contour detection unit

[0254] LB laser.

Claims

1. A laser device for irradiating a laser onto an object, the laser device comprising: A laser source, emitting the laser; An optical system configured to irradiate the object with laser light emitted from the laser light source and to change a beam profile of the laser light irradiated to the object; a profile detection unit that detects a beam profile of the laser beam irradiated from the optical system to the irradiated object; and a control unit that controls the optical system at each preset control cycle so that the beam profile detected by the profile detection unit becomes a desired beam profile, The irradiated object is an optical fiber having a first core and a second core surrounding the first core. The laser light emitted from the optical system is irradiated to the end of the optical fiber. The beam profile detected by the profile detection unit includes the position of the laser spot at the end of the optical fiber, The control unit controls the optical system so that the position of the light spot detected by the profile detection unit becomes a target light spot position corresponding to the desired light beam profile. When the target spot position is set to a position straddling the first core and the second core of the optical fiber, that is, a boundary position, the control unit sets the control cycle to a first cycle, When the target spot position is not set at the boundary position, the control unit sets the control cycle to a second cycle that is longer than the first cycle.

2. The laser device according to claim 1, wherein: The control unit outputs abnormal difference notification information for notifying abnormality of the difference when a difference between a spot position of the laser light at the end of the optical fiber detected by the contour detection unit and the target spot position exceeds a preset allowable difference.

3. The laser device according to claim 1, wherein: The control unit outputs control failure notification information for notifying that control is impossible when the beam profile detected by the profile detection unit cannot be set to the desired beam profile even if the optical system is controlled.

4. The laser device according to claim 1, wherein: The control unit changes the control cycle according to the stability of the beam profile detected by the profile detection unit.

5. The laser device according to claim 1, wherein: The laser device comprises: a temperature detection unit for detecting the ambient temperature of the optical system; The control unit changes the control cycle according to the ambient temperature detected by the temperature detection unit.

6. The laser device according to claim 1, wherein: The laser device includes: a timing unit for measuring the elapsed time from the start of driving of the laser light source; The control unit changes the control cycle according to the elapsed time measured by the timing unit.

7. The laser device according to claim 1, wherein: The control unit outputs correction abnormality notification information for notifying correction abnormality when the beam profile detected by the profile detection unit is not the desired beam profile and the number of corrections of the optical system by the control unit exceeds a preset threshold.

8. A method for controlling a laser device, The laser device comprises: a laser source for emitting laser light; and an optical system configured to irradiate the laser light emitted from the laser source to the end of an optical fiber having a first core and a second core surrounding the first core, and capable of changing the beam profile of the laser light irradiated to the end of the optical fiber. The control method of the laser device comprises: A detection step of detecting the position of the laser spot at the end of the optical fiber; a control step of controlling the optical system at each preset control cycle so that the position of the light spot detected by the detection step becomes a target light spot position corresponding to a desired beam profile; and An adjustment step, in which when the target light spot position is set at a position spanning the first core and the second core of the optical fiber, i.e., a boundary position, the control period is set to a first period; and in which when the target light spot position is not set at the boundary position, the control period is set to a second period that is longer than the first period.

Images