Beam coupling device and laser processing machine

Abstract

The present disclosure provides a beam coupling device and a laser processing machine. The beam coupling device (2) includes a light source (30), a plurality of optical units (4), and a coupling optical system (20). The light source includes a plurality of light source elements (31) arranged in a first direction (X) and a second direction (Y), and a plurality of light beams having light directions intersecting the first direction and the second direction are emitted from each light source element. The plurality of optical units (4) guide each light beam according to each group (3) of light source elements arranged along the first direction in the light source. The coupling optical system couples the plurality of light beams guided by each optical unit. In the group of light source elements, each optical unit directs the light direction (La) of the light beam from the light source element located outside in the first direction outward, and guides the light beam from each light source element to the coupling optical system.

Description

Technical Field

[0001] The present disclosure relates to a beam coupling device and a laser processing machine including the beam coupling device. Background Art

[0002] Patent Document 1 discloses a wavelength combining laser system that superimposes individual beams to form a coupled beam. Patent Document 1 discloses that, to increase light output, the beams from multiple diode bars are focused onto an optical fiber. Furthermore, to miniaturize the laser system, the system also includes an optical system for shifting the arrangement of the coupling lens in wavelength combining from the focal length, or for rotating the beam rotor.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: U.S. Patent No. 2016 / 0048028 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] The present disclosure provides a beam coupling device capable of coupling a plurality of light beams at high density, and a laser processing machine including the beam coupling device.

[0008] Technical solutions to solve problems

[0009] The beam coupling device disclosed herein comprises a light source, a plurality of optical units, and a coupling optical system. The light source includes a plurality of light source elements arranged in a first direction and a second direction intersecting each other, and a plurality of light beams having light directions intersecting the first direction and the second direction are emitted from each light source element. The plurality of optical units guide each light beam according to each group of light source elements arranged along the first direction in the light source. The coupling optical system couples the plurality of light beams guided by each optical unit. In the group of light source elements, each optical unit directs the light beam from the light source element located on the outside in the first direction outward, and guides the light beam from each light source element to the coupling optical system.

[0010] The laser processing machine according to the present disclosure includes the above-mentioned beam coupling device and a processing head for irradiating a processing object with the light beam coupled by the beam coupling device.

[0011] Effects of the Invention

[0012] According to the beam coupler and the laser processing machine according to the present disclosure, a plurality of light beams can be coupled at a high density in the beam coupler. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1This is a block diagram illustrating the configuration of the laser processing machine according to the first embodiment of the present disclosure.

[0014] Figure 2 This is a diagram showing the overall configuration of the beam coupler according to the first embodiment.

[0015] Figure 3 FIG. 1 is a diagram illustrating the outward direction of the outer principal ray in the beam coupling device.

[0016] Figure 4 This is a diagram illustrating a coupling optical system in a beam coupling device.

[0017] Figure 5 It is a diagram illustrating the focal length of the cylindrical lens of the coupling optical system.

[0018] Figure 6 This is a diagram illustrating a basic structure of an optical unit in a beam coupler.

[0019] Figure 7 It is a perspective view showing a configuration example of a beam rotator unit in the optical unit.

[0020] Figure 8 This is a diagram showing a configuration example of an optical unit in the beam coupler according to the first embodiment.

[0021] Figure 9 This is an example Figure 8 Light path diagram of the principal ray in the optical unit.

[0022] Figure 10 This is a diagram showing a first configuration example of an outer optical unit in a beam coupler.

[0023] Figure 11 This is a diagram showing a second configuration example of an outer optical unit in a beam coupler.

[0024] Figure 12 This is a diagram showing an example of the beam coupler according to the first embodiment.

[0025] Figure 13 This is a diagram showing a configuration example of an optical unit in a beam coupler according to a second embodiment.

[0026] Figure 14 yes Figure 13 Cross-sectional view of the optical unit.

[0027] Figure 15 This is an example Figure 13 Light path diagram of the principal ray in the optical unit.

[0028] Figure 16 This is a diagram showing an example of a beam coupler according to the second embodiment.

[0029] Figure 17 A diagram showing a modified example of the beam coupler. DETAILED DESCRIPTION

[0030] The following describes the embodiments in detail with reference to the accompanying drawings as appropriate. However, detailed descriptions beyond those necessary may be omitted. For example, detailed descriptions of well-known matters or repeated descriptions of substantially identical structures may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art.

[0031] In addition, the applicant provides the drawings and the following description to enable those skilled in the art to fully understand the present disclosure, and the applicant does not intend that the subject matter described in the claims be limited by them.

[0032] (Implementation Method 1)

[0033] In the first embodiment, a spatial combining type beam coupling device and a laser processing machine including the beam coupling device will be described.

[0034] 1. About laser processing machines

[0035] use Figure 1 The laser processing machine according to the first embodiment will be described.

[0036] Figure 1 This figure illustrates the configuration of a laser processing machine 1 according to this embodiment. The laser processing machine 1 includes, for example, a beam coupling device 2, a transmission optical system 10, a processing head 11, and a controller 12. The laser processing machine 1 irradiates various processing objects 15 with laser light to perform various laser processing operations. Examples of these laser processing operations include laser welding, laser cutting, and laser drilling.

[0037] In this embodiment, the beam coupler 2 includes a laser light source 30, a plurality of optical units 4-1 to 4-3, and a coupling optical system 20. In this embodiment, the laser light source 30 includes a plurality of LD bars 3-1 to 3-3. Hereinafter, the LD bars 3-1 to 3-3 may be collectively referred to as "LD bar 3," and the optical units 4-1 to 4-3 may be collectively referred to as "optical unit 4."

[0038] The LD bar 3 is composed of an array of light source elements comprising multiple LDs (laser diodes) arranged one-dimensionally. In the beam coupler 2, the multiple LD bars 3 are arranged side by side in a direction perpendicular to the arrangement direction, for example, with the LDs arranged in parallel. While the number of LD bars 3 in the beam coupler 2 is shown as three, this is not particularly limited and may be two or four or more.

[0039] Hereinafter, the direction in which the plurality of LDs in the LD bar 3 are arranged is referred to as the "X direction", the direction in which the plurality of LD bars 3-1 to 3-3 are arranged is referred to as the "Y direction", and the direction perpendicular to the X and Y directions is referred to as the "Z direction".

[0040] The beam coupler 2 of this embodiment is a device that performs spatially combining beam coupling by coupling multiple beams emitted by each of the LDs in a plurality of LD bars 3 spatially arranged in a laser light source 30, for example, the laser light supplied to the laser processing machine 1. In this embodiment, a beam coupler 2 capable of high-density beam coupling with a small beam diameter is provided.

[0041] In the beam coupler 2 of this embodiment, a plurality of optical units 4 are provided, for example, as many as the number of LD bars 3. Each optical unit 4 is an optical system that guides the light beams from each LD in a single LD bar 3 to the coupling optical system 20. The coupling optical system 20 is an optical system in the beam coupler 2 that couples the light beams from each optical unit 4. The beam coupler 2 will be described later.

[0042] In the laser processing machine 1, the transmission optical system 10 includes an optical fiber configured to receive, for example, a light beam coupled by the coupling optical system 20, and transmits the laser light from the beam coupler 2 to the processing head 11. The processing head 11 is, for example, a device arranged to face the processing object 15 and irradiates the processing object 15 with the laser light transmitted from the beam coupler 2.

[0043] The controller 12 is a control device that controls the overall operation of the laser processing machine 1. The controller 12 may include, for example, a CPU or MPU that works in conjunction with software to implement specified functions. The controller 12 includes internal memory, such as flash memory, to store various programs and data. The controller 12 may also include various interfaces that allow the user to input oscillation conditions, etc. Furthermore, the controller 12 may include hardware circuits, such as ASICs and FPGAs, to implement various functions. Furthermore, the controller 12 may be integrated with the driver circuit of the laser light source 30.

[0044] 2. About the beam coupling device

[0045] use Figure 2 The beam coupler 2 according to this embodiment will be described.

[0046] Figure 2 1 is a diagram showing the overall structure of the beam coupler 2 . Figure 2 (A) shows a side view of the beam coupler 2 as viewed from the X direction. Figure 2 (B) shows a top view of the beam coupler 2 as viewed from the Y direction.

[0047] In the beam coupling device 2 of this embodiment, for example, Figure 2 As shown in (A), each LD bar 3 is arranged on the -Z side of its respective optical unit 4. Each optical unit 4 includes a BTU (beam rotator unit) 40 arranged opposite the LD bar 3 and a SAC (slow axis collimator) 45 arranged on the +Z side of the BTU 40. The coupling optical system 20 is arranged on the +Z side of the optical unit 4 and includes an axisymmetric condenser lens 21 and a cylindrical lens 22 arranged between the condenser lens 21 and the optical unit 4.

[0048] exist Figure 2 In (B), five LDs 31a, 31b, 31c, 31d, and 31e are illustrated in LD bar 3. The number of LDs 31a to 31e contained in one LD bar 3 can range from tens to hundreds, for example. The multiple LDs 31a to 31e in LD bar 3 are an example of a set of light source elements in laser light source 30 of this embodiment. Hereinafter, LDs 31a to 31e may be collectively referred to as "LDs 31." Each LD 31 constitutes an emitter in LD bar 3, emitting a light beam toward the +Z side.

[0049] exist Figure 2 In (A) and (B), beam coupling position P1 is shown as an example of the coupling result of the light beam by beam coupler 2. Beam coupling position P1 is set, for example, at a position where the beam diameter of the light beam emitted from each of LDs 31a to 31e in all LD bars 3-1 to 3-3 is minimized. For example, the incident end of the optical fiber of the transmission optical system 10 described above is arranged at beam coupling position P1.

[0050] exist Figure 2 In (A), the principal ray L1 of the light beam from the outer LD bar 3-1 in the Y direction and the principal ray L2 of the light beam from the central LD ​​bar 3-2 are illustrated. Figure 2 In (B), the principal ray La of the light beam from the outer LD 31a in the X direction and the principal ray Lc of the light beam from the central LD ​​31c are illustrated. In the beam coupler 2 of this embodiment, for example, the central LD ​​31c in the X and Y directions has a principal ray Lc that travels straight through the opposing optical unit 4 and coupling optical system 20 and is parallel to the Z direction.

[0051] In this embodiment, for example, from the viewpoint of increasing the output of the beam coupler 2 due to spatial combining, as shown in FIG. Figure 2As shown in (A), the corresponding optical unit 4 is configured to direct the principal ray L1 of the light beam emitted by the outermost LD bar 3-1 among the multiple LD bars 3 arranged in the Y direction inward (details will be described later). For example, the optical unit 4 on the upper side (+Y side) in the figure tilts the principal ray L1 of the light beam downward (-Y side) from the Z direction. In this case, the beam coupling position P1 in the Y direction, where the principal rays L1 and L2 of the LD bars 3 intersect, is located further to the -Z side than the focal position P0 of the condenser lens 21.

[0052] On the other hand, Figure 2 As shown in (B), the beam coupler 2 of this embodiment is configured so that the principal ray La of the light beam from the outer LD 31a is directed outward, within the plurality of LDs 31a to 31e arranged in the X direction for each LD bar 3. This reduces the beam diameter of each light beam during coupling, increasing the density of the light beams incident on the coupling optical system 20, as will be described in detail below. Furthermore, to ensure that the beam coupling position P1 in the X and Y directions is aligned, the beam coupler 2 of this embodiment uses a cylindrical lens 22 in the coupling optical system 20. The beam coupler 2 is described in detail below.

[0053] 2-1. Details of the beam coupling device

[0054] First, in the beam coupling device 2 of this embodiment, the Figure 3 The effect of directing the principal ray La on the outer side in the X direction outward without using the cylindrical lens 22 will be described.

[0055] Figure 3 (A) shows the optical paths of various light rays in the beam coupling device 2 when the cylindrical lens 22 is not provided. The various light rays include Figure 2 (B) The same main light La, Lc and their peripheral light.

[0056] exist Figure 3 (A) illustrates the optical paths before and after directing the principal ray La outward in the X direction. Furthermore, for example, the optical image of the +Z side surface of BTU 40 is formed by condenser lens 21 at imaging position P2. At imaging position P2, the average beam diameter of a single LD 31 is minimized. Meanwhile, the combined beam diameter of the multiple LDs 31a to 31e is minimized at the point where their principal rays intersect.

[0057] According to the beam coupler 2 of this embodiment, by directing the principal ray La of the light beam from the outer LD 31a outward, the intersection point P11 of the principal rays La and Lc is located closer to the +Z side than the focal point P0. In other words, by directing the outer principal ray La outward, the intersection point P11 of the principal rays La and Lc can be brought closer to the image formation position P2.

[0058] Figure 3 (B) shows Figure 3 This is an enlarged view of the area near the focal position P0 of the condenser lens 21 in (A). At the focal position P0 of the condenser lens 21, the beam diameter B0 of each LD 31 becomes larger by an amount corresponding to the distance from the image formation position P2. In contrast, at the intersection position P11 (when the principal ray La is directed outward), the beam diameter B11 of each LD 31 becomes smaller by an amount corresponding to the distance from the focal position P0 to the image formation position P2.

[0059] Therefore, the beam coupler 2 of this embodiment can reduce the beam diameter during coupling not only from the perspective of combining multiple beams but also from the perspective of each beam, thereby achieving high-density beam coupling and improving beam quality.

[0060] Here, it is considered that the following new problems will arise, namely, Figure 3 The intersection position P11 shown in (A) and (B) is closer to the +Z side than the focal position P0 of the condenser lens 21, and the beam coupling position P1 when the outer principal ray in the Y direction is directed inward (see Figure 2 Therefore, in this embodiment, a cylindrical lens 22 having positive refractive power only in the X direction is used in the coupling optical system 20 to eliminate the mismatch between the X and Y directions.

[0061] 2-1-1. About the Coupling Optical System

[0062] Figure 4 1 and 2 are diagrams for explaining the effects of the cylindrical lens 22 of the coupling optical system 20 in the beam coupler 2 according to the present embodiment. Figure 4 (A) and (B) are examples of the beam coupling device 2 including the cylindrical lens 22. Figure 3 The optical paths of the same principal rays La and Lc as in (A) and (B).

[0063] like Figure 4 As shown in (A) and (B), the focal position P10 of the coupling optical system 20 as a whole in the X direction is closer to the -Z side than the focal position P0 of the condenser lens 21 due to the cylindrical lens 22. In this case, the position where the chief rays La and Lc intersect each other when directed outward in the X direction, that is, the beam coupling position P1, is replaced by Figure 3 In the examples (A) and (B), the focal position P0 of the condenser lens 21 is located further to the +Z side than the focal position P10 described above. Therefore, by bringing the beam coupling position P1 closer to the image formation position P2 within a range further to the -Z side than the focal position P0 of the condenser lens 21, the beam diameter can be reduced in the same manner as in the above example.

[0064] Furthermore, the cylindrical lens 22 has no refractive power in the Y direction, so Figure 2 As shown in (A), in particular, it does not interfere with the principal ray L1 inward from the outside in the Y direction. Therefore, the beam coupling position P1 in the Y direction can be maintained at the -Z side relative to the focal position P0 of the condenser lens 21 regardless of whether the cylindrical lens 22 is present. Therefore, according to the coupling optical system 20 of this embodiment, by using the refractive power in the X direction greater than that in the Y direction, as shown in FIG. Figure 2 As shown in (A) and (B) of FIG. 1 , the beam coupling position P1 can be matched in the X direction and the Y direction.

[0065] Figure 5 This diagram illustrates the focal length D2 of the cylindrical lens 22. In the coupling optical system 20 of this embodiment, the cylindrical lens 22 has a relatively long focal length D2, for example, equal to or greater than the focal length of the condenser lens 21. For example, the focal length D2 of the cylindrical lens 22 may be shorter than the distance D1 from position P20 to the cylindrical lens 22. Position P20 is the intersection of the extension line Ea of the principal ray La extending outward in the X direction toward the -Z side and the extension line Ec of the central principal ray Lc. The extension line Ec corresponds to the optical axis of the condenser lens 21, for example.

[0066] Based on the focal length D2 described above, the refractive power of the cylindrical lens 22 can be such that, after the principal ray La on the outer side of the X direction enters the cylindrical lens 22 with an outward orientation, it is directed inward upon exiting the condenser lens 21. With this refractive power, the principal rays La and Lc intersect on the -Z side of the focal position P0 of the condenser lens 21. Furthermore, the distance between the cylindrical lens 22 and the BTU 40 can be set to the focal length D2 of the cylindrical lens 22.

[0067] In the above description, an example of using the cylindrical lens 22 in the coupling optical system 20 is described, but it is not necessary to use the cylindrical lens 22. For example, various optical systems having a positive refractive power greater in the X direction than in the Y direction may be used in the coupling optical system 20. For example, as long as the refractive power in the X and Y directions of the coupling optical system 20 as a whole is equal to Figure 2 By using an optical system with the same structure as above, the beam coupling position P1 in the X and Y directions can be matched.

[0068] 2-2. About the optical unit

[0069] Hereinafter, the optical unit 4 of the beam coupler 2 in this embodiment will be described in detail.

[0070] 2-2-1. Basic structure of the optical unit

[0071] First, use Figures 6 and 7 The basic structure of the optical unit 4 will be described. Figure 6 The basic structure of the optical unit 4 is exemplified.

[0072] Figure 6 (A) shows a top view of the optical unit 4 in the basic structure. Figure 6 (B) shows Figure 6 (A) is a side view of the optical unit 4. Figure 6 In (A) and (B), the optical path of the light beam from one LD 31 is illustrated.

[0073] The BTU 40 in the optical unit 4 includes a BT (beam rotator) 50 and a FAC (fast axis collimator) 41. In the optical unit 4, for example, the FAC 41, the BT 50, and the SAC 45 are arranged in this order from the vicinity of the LD 31 toward the +Z side.

[0074] In this embodiment, LD 31 emits a light beam having a fast axis Af and a slow axis As. The fast axis Af expands the beam diameter more rapidly than the slow axis As, making it easier to achieve good beam quality. Before the light beam from LD 31 enters the optical unit 4, the fast axis Af is oriented in the Y direction, and the slow axis As is oriented in the X direction.

[0075] FAC41 is provided to collimate the light beam on the fast axis Af, and is composed of, for example, a cylindrical lens having a positive refractive power. Figure 6 As shown in (A) and (B) of FIG5 , the FAC 41 is arranged with its longitudinal direction facing the X direction. In this example, the light beam from the LD 31 is collimated in the Y direction (ie, the fast axis Af) by the FAC 41 and enters the BT 50 .

[0076] exist Figure 7 , an example of the structure of the BT50 is shown in FIG. The BT50 is, for example, an optical element that rotates multiple light beams individually and includes multiple oblique lens sections 51. In the BT50, the oblique lens section 51 is a portion of the lens that constitutes each LD 31, and is, for example, a cylindrical lens. The BT50 is formed, for example, by arranging multiple oblique lens sections 51 at predetermined intervals in the longitudinal direction. The oblique lens sections 51 are, for example, inclined at 45° with respect to both the arrangement direction and the thickness direction of the BT50. The pitch of the oblique lens sections 51 is, for example, the same as the pitch between the LDs 31 in the LD bar 3.

[0077] exist Figure 6 In the examples (A) and (B), the BT50 rotates the light beam incident from the LD31 via the FAC41 by 90° in the XY plane. As a result, the slow axis As of the light beam emitted from the BT50 is oriented in the Y direction, and the fast axis Af is oriented in the X direction. Furthermore, the light beam emitted from the BT50 becomes divergent in the Y direction and parallel in the X direction.

[0078] SAC45 is provided to collimate the light beam on the slow axis As, and is composed of, for example, a cylindrical lens having a positive refractive power. Figure 6 As shown in (A) and (B) of FIG. , the SAC 45 is arranged with its longitudinal direction facing the X direction. In this example, the light beam from the BT 50 is collimated in the Y direction (ie, the slow axis As) by the SAC 45 and emitted from the optical unit 4 .

[0079] According to the above optical unit 4, the light beams emitted from each LD 31 of the LD bar 3 are essentially collimated along the fast axis Af and the slow axis As. However, due to the wave properties of light, particularly the influence of waves on the fast axis Af from the +Z side surface of the BT 50, the beam diameter may be increased. In contrast, according to the optical unit 4 of this embodiment, the outward transmission of the principal ray in the X direction and the coupling optical system 20 can reduce this influence and reduce the beam diameter.

[0080] In this embodiment, the outward and inward directions of various principal rays are realized by utilizing the basic functions of the various parts of the optical unit 4. Hereinafter, a configuration example of such an optical unit 4 will be described.

[0081] 2-2-2. Example of a structure with X direction facing outward

[0082] Figure 8 A configuration example of the optical unit 4 in the beam coupler 2 according to this embodiment is shown. Figure 8 A front view of the optical unit 4 viewed from the -Z side is shown together with the LDs 31a to 31e.

[0083] In the beam coupler 2 of this embodiment, from the viewpoint of directing the outer principal rays in the X direction outward, for example, each optical unit 4 is configured as follows: Figure 8 The optical unit 4 of this embodiment is configured as shown. For example, the BTU 40 is configured so that the longitudinal direction is rotated from the X direction by a predetermined rotation angle θo (e.g., 0.001° ≤ θo ≤ 1°) about the position where the principal ray of the LD 31c passes in the center of the XY plane as the rotation axis. The direction of the rotation angle θo is clockwise in the figure and is the direction that increases the angle of inclination of the extension direction of the cylindrical lens 22 within the BT 50 relative to the X direction. The rotation angle θo can be common to multiple optical units 4 or can be set individually.

[0084] Figure 9 (A) to (C) illustrate the optical path in the optical unit 4 of this configuration example. Figure 9 (A) and Figure 8The AA cross section corresponds to the AA cross section in the optical unit 4. The AA cross section is the XZ plane where the LDs 31a to 31e of the LD bar 3 are located. Figure 9 (B) and (C) are respectively Figure 9 The BB cross-sectional view and CC cross-sectional view in (A) correspond to each other. The BB cross-sectional view is the YZ plane where the central LD31c is located. The CC cross-sectional view is the YZ plane where the outer LD31a is located.

[0085] In the optical unit 4 of this configuration example, the farther the LD 31a ( Figure 9 (A)), the more the positional relationship between LD31a and BTU40 deviates ( Figure 9 Thus, for example, Figure 9 As shown in (C), the principal ray La of the outer LD 31a has an inclination from the Z direction toward the Y direction when emitted from the FAC 41.

[0086] The light beam from LD31 is rotated by 90° on the XY plane in BT50. Thus, for example, Figure 9 As shown in (A), the tilt of the principal ray La of the outer LD31a is converted into a tilt in the X direction. Therefore, according to the rotation angle θo of the BTU40, the more the LD31 is located on the outer side, the more the principal ray can be directed outward in the X direction. Figure 9 As shown in (C), regarding the outer LD 31a, the positional relationship between the BTU 40 and the SAC 45 is offset, so the principal ray La can be tilted in the Y direction after being emitted from the SAC 45. However, such tilt can be kept at a slight level.

[0087] 2-2-3. Example of structure with Y direction facing inward

[0088] In addition to the above-mentioned structure, the beam coupler 2 of this embodiment also has a partially modified basic structure of the optical unit 4-1 corresponding to the outer LD bar 3-1 from the viewpoint of directing the outer principal ray L1 in the Y direction inward. Figure 10 、 Figure 11 An example of such a configuration will be described.

[0089] Figure 10Structural example 1 of the outer optical unit 4-1 in the Y direction is shown. In this structural example, in the optical unit 4 on the outer side in the Y direction (for example, the +Y side), the SAC45 is configured to be displaced by a given displacement amplitude ΔY from the same position as the central optical unit 4 to the inner side (for example, the -Y side). Thus, the SAC45 can shift the main ray L1 from the optical axis for collimating the incident light beam, and direct the light beam emitted from the outer optical unit 4-1 inward. The displacement amplitude ΔY specifies the amplitude by which the optical axis of the SAC45 is shifted from the position where the main ray L1 is incident on the SAC45, according to the degree to which the main ray L1 is directed inward. By directing the main ray L1 from the outer optical unit 4-1 inward, as shown in FIG. Figure 2 As shown in (A), the interval between the principal rays L1 and L2 reaching the condenser lens 21 from the plurality of optical elements 4-1 and 4-2 becomes smaller than the interval between the optical elements 4-1 and 4-2. Therefore, the number of optical elements 4 that are spatially combined by the condenser lens 21 can be increased, and the number of LD bars 3 can be increased, thereby increasing the light output by spatial combination in the beam coupler 2.

[0090] When the number of optical units 4 is increased, for example, the displacement width ΔY is set larger for the outer optical units 4. Thus, the outer optical units 4 in the Y direction tilt the principal rays more inward, so that the positions where the principal rays intersect are aligned.

[0091] The configuration in which the principal light ray L1 on the outer side in the Y direction is directed inward is not limited to the above-described configuration example. Figure 11 Example 2 of the configuration of the outer optical unit 4-1 in the Y direction is shown. In this configuration example, the outer optical unit 4-1 in the Y direction is arranged in the same orientation as the central optical unit 4, but tilted inward at a predetermined tilt angle θi in the YZ plane. The tilt angle θi is appropriately set depending on the degree to which the principal ray L1 is directed inward.

[0092] According to the above-described configuration example 2, the light beam emitted from the outer optical unit 4-1 can also be directed inward, similar to configuration example 1. Alternatively, in the optical unit 4-1, the SAC 45 may not be tilted, and only the BTU 40 may be tilted. Furthermore, the LD bar 3 may be tilted, for example, depending on the orientation of the corresponding optical unit 4, or may not be specifically tilted.

[0093] 2-3. Example of Implementation Method 1

[0094] Hereinafter, examples related to the configuration example of the beam coupler 2 according to the present embodiment as described above will be described.

[0095] As a numerical example of the beam coupler 2 of this embodiment, Figure 10 、 Figure 11In this simulation, the interval between the plurality of optical units 4 is set to 4.8 mm, the focal length of the SAC 45 is set to 15 mm, and the focal length of the condenser lens 21 is set to 50 mm.

[0096] As Figure 10 In the simulation, the displacement width ΔY of the SAC 45 was set to “ΔY=0.0560 mm.” Thus, it was confirmed that the principal ray L1 on the outer side in the Y direction was directed inward at a distance of 1.5 mm when it reached the coupling optical system 20 .

[0097] Furthermore, in this simulation, the rotation angle θo of the BT50 was set to θo=0.01°. At this time, the use of the cylindrical lens 22 with a focal length of 500 mm in the coupling optical system 20 confirmed the effect of matching the beam coupling position P1 between the X and Y directions.

[0098] In addition, as Figure 11 In the simulation, in the same simulation environment as above, not only was ΔY set to 0, but the tilt angle θi of the optical unit 4 was also set to θi = 0.18°. Even in such a simulation, the same effect as above was confirmed.

[0099] Figure 12 The following figure shows the simulation results of the beam coupler 2 according to this embodiment. In this simulation, numerical calculations were performed on the +X side of the principal ray to confirm the effect of the rotation angle θo (= 0.01°) of the BTU 40 under the same settings as described above. Each row in the figure shows the numerical calculation results of the principal ray passing through each part of the beam coupler 2, numbered for each surface from the object side (i.e., -Z side) to the image side (i.e., +Z side). As the numerical calculation results, "X" represents the X coordinate, "Y" represents the Y coordinate, "TANX" represents the tilt in the XZ plane using the tan function, and "TANY" represents the tilt in the YZ plane using the tan function. The position of LD 31 corresponding to the numerically calculated principal ray is 4 mm at the X coordinate.

[0100] according to Figure 12 The simulation results show that "TANX," which was zero when emitted from LD31, becomes a positive value of "0.00437" after being emitted from SAC45, indicating that the principal ray on the +X side is directed outward. Furthermore, the value of "TANY," 0.00032, at this point is significantly smaller than the aforementioned "TANX." Therefore, it was confirmed that the rotation angle θo of BT50 allows the principal ray on the outer side of the X direction to maintain a slight tilt in the Y direction, thus directing it outward in the X direction. Furthermore, it was confirmed that this principal ray, after being emitted from cylindrical lens 22, is directed inward in the X direction.

[0101] 3. Summary

[0102] As described above, in this embodiment, the beam coupling device 2 includes a laser light source 30 as an example of a light source, a plurality of optical units 4, and a coupling optical system 20. The laser light source 30 includes a plurality of LDs 31 as an example of a plurality of light source elements, which are arranged in the X direction as an example of a first direction and the Y direction as an example of a second direction intersecting the first direction. The laser light source 30 emits a plurality of light beams from each LD 31, each having a light direction intersecting the X and Y directions. The light direction of each LD 31 is defined, for example, by the principal ray of each light beam. The plurality of optical units 4 guide each light beam for each LD bar 3, which is an example of a group of LDs 31 arranged in the X direction in the laser light source 30. The coupling optical system 20 couples the plurality of light beams guided by each optical unit 4. Within the LD bar 3, each optical unit 4 directs the light direction (e.g., principal ray La) of the light beam from the outer LD 31a located in the X direction outward, and guides the light beam from each LD 31 to the coupling optical system 20.

[0103] According to the above-described beam coupling device 2, the position where the principal rays of each LD 31 intersect in the X direction can be moved closer to the imaging position than the focal position of the coupling optical system 20. This reduces the beam diameter of the light beams during coupling, enabling high-density coupling of multiple light beams. Furthermore, the first and second directions do not need to be perpendicular to each other; they can intersect within an appropriate angular tolerance.

[0104] In this embodiment, the coupling optical system 20 has a larger positive refractive power in the X direction than in the Y direction. In the laser light source 30, among the LD bars 3-1 and 3-2 including a plurality of LDs 31 arranged in the Y direction, the plurality of optical units 4 direct the light beams (e.g., principal light beam L1) from the LDs 31 of the outer LD bar 3-1 inward.

[0105] This allows light beams to be supplied to the coupling optical system 20 at intervals narrower than the intervals between the optical units 41 in the Y direction, enabling increased output of the beam coupling device 2 through spatial combining. Furthermore, in this case, the refractive power of the coupling optical system 20 allows alignment of the beam coupling position P1 where the beam diameter is minimized in both the X and Y directions.

[0106] In this embodiment, the coupling optical system 20 includes an axisymmetric condenser lens 21 and a cylindrical lens 22 having positive refractive power in the X direction. The refractive power of the cylindrical lens 22 is such that, for example, the direction of the light beam from the outer LD 31a in the X direction is adjusted from an outward direction at the time of incidence to an inward direction at the time of emission.

[0107] For example, the cylindrical lens 22 has a focal length D2 that is shorter than the distance D1 from the position P20 to the cylindrical lens 22. The position P20 is the position where the extension line Ea of the principal ray La of the outward-directed light beam extending from the optical unit 4 toward the laser light source 30 intersects the extension line Ec of the optical axis of the condenser lens 21. This allows the cylindrical lens 22 to have a refractive power sufficient to direct the light beam from the LD 31a located outside in the X direction inward when emitted.

[0108] In this embodiment, each optical unit 4 includes a SAC 45 as an example of a collimating lens, and the collimating lens collimates each light beam from the LD 31 of the LD bar 3 in the Y direction. Figure 10 As shown, among the plurality of optical units 4-1 and 4-2, the SAC 45 of the optical unit 4-1 located on the outer side in the Y direction is arranged at a position that directs the incident light beam inward. This allows the outer principal ray L1 in the Y direction to be directed inward.

[0109] In this embodiment, for example, Figure 10 As shown, the optical units 4 located on the outer side in the Y direction may be arranged so that the light beam incident from the light source is emitted inward. This also enables the outer principal light beam L1 in the Y direction to be directed inward.

[0110] In this embodiment, the optical unit 4 includes a BTU 40 that rotates each light beam from LD 31 of the LD bar 3. The BTU 40 is positioned relative to the LD bar 3 at a rotation angle θo that causes the light beam from LD 31a located on the outer side in the X direction to be directed outward. This allows the principal light beam La to be directed outward on the outer side in the X direction.

[0111] In this embodiment, a laser processing machine 1 includes a beam coupler 2 and a processing head 11 that irradiates a processing object with the beam coupled by the beam coupler 2. In the laser processing machine 1, the beam coupler 2 can couple a plurality of beams at a high density.

[0112] (Implementation Method 2)

[0113] Below, using Figures 13 to 16 Embodiment 2 will be described. In Embodiment 1, the principal ray La directed outward in the X direction is directed outward by the rotation of the BT50 of the optical unit 4. In Embodiment 2, another example of the structure for directing the principal ray La outward will be described.

[0114] Hereinafter, description of the configuration and operation similar to those of the laser processing machine 1 and the beam coupler 2 according to the first embodiment will be appropriately omitted, and the beam coupler 2 according to the present embodiment will be described.

[0115] Figure 13The following is a configuration example of BT50A of the optical unit 4A in the second embodiment. The beam coupler 2 of this embodiment has the same configuration as that of the first embodiment, but includes a Figure 8 The optical unit 4A of the present embodiment replaces the BT50 having the rotation angle θo in the optical unit 4 of the first embodiment, for example, Figure 13 BT50A of the present embodiment has different pitches of the oblique lens portions 51 on the emission side and the incident side, ie, the ±Z sides, of the light beam from the LD 31 .

[0116] Figure 14 Show Figure 13 A cross-sectional view of the XZ plane of the BT50A of this structural example is shown. The BT50A of this structural example is configured so that the spacing Wo between the oblique lens portions 51 on the +Z side surface is larger than the spacing Wi on the -Z side surface. The spacing Wi on the -Z side is set to match the spacing between the LDs 31 in the LD strip 3, for example, as in the BT50 of the first embodiment. In the BT50A of this structural example, for example, the center of the central oblique lens portion 51 is aligned on both the ±Z side surfaces. In addition, the curved surface shape of the oblique lens portion 51 on the +Z side surface can be set to, for example, extend the curved surface shape on the -Z side.

[0117] Figure 15 (A) to (C) illustrate the optical path in the optical unit 4A of this embodiment. Figure 15 (A) corresponds to Figure 13 In the optical unit 4A of the structural example Figure 8 The AA section is the same section. Figure 15 (B) and (C) correspond to Figure 15 BB cross-sectional view and CC cross-sectional view in (A) . As in the first embodiment, the BT50A of this embodiment is adjacent to the SAC 45 on the +Z side and adjacent to the FAC 41 on the -Z side.

[0118] According to the optical unit 4A of this embodiment, as Figure 15 As shown in (A) to (C) of FIG50A , the principal ray of the light beam from each LD 31 travels straight along the Z direction from the time it enters the FAC 41 until it reaches the +Z side surface of the BT 50A. On the +Z side surface of the BT 50A, the pitch Wo of the oblique lens portion 51 is larger than that on the -Z side surface, so the principal ray La travels further outward in the X and Y directions for the LD 31a located farther outward in the X direction.

[0119] Each main light beam La, Lc, when emitted from BT50A, reaches SAC45. Here, SAC45 performs collimation of the light beam in the Y direction, so Figure 15 As shown in (C), the inclination of the main light ray Lc in the Y direction is corrected in the SAC45.

[0120] As described above, according to the optical unit 4A of the present embodiment, the principal ray Lc of the LD 31 c on the outer side in the X direction can be restricted in the X direction so as to be directed outward.

[0121] Figure 16 The following table shows simulation results for the beam coupler 2 according to Embodiment 2. In this simulation, numerical calculations similar to those in Embodiment 1 were performed with "θo = 0" and the pitch Wo on the +Z side of the BT50A set to be 318 nm larger than the pitch Wi on the -Z side. The pitch Wi on the -Z side of the BT50A and the inter-LD pitch of the LD bar 3 were set to 0.225000 mm.

[0122] according to Figure 16 The simulation results of Figure 12 Similarly, "TANX" becomes a positive value "0.00443" after being emitted from SAC45, and the main ray on the +X side is directed outward. On the other hand, the value "TANY" at this time is "0.00003", which is larger than Figure 12 Therefore, according to the optical unit 4A of this embodiment, it was confirmed that, similarly to the first embodiment, the principal ray in the outer side of the X direction can be directed outward and the influence in the Y direction can be reduced.

[0123] As described above, in the beam coupler 2 of this embodiment, the optical unit 4A includes a BT50A, which is an example of a light source element. The BT50A includes multiple oblique lens portions 51 corresponding to the respective LDs 31 in the LD bar 3. In the BT50A, the multiple oblique lens portions 51 are tilted relative to the Y direction and arranged in the X direction. On both surfaces of the BT50A, the pitch Wo between the multiple oblique lens portions 51 on the +Z side, where the light beams from the group of LDs 31 are emitted, is greater than the pitch Wi between the multiple oblique lens portions 51 on the -Z side, where the light beams are incident. According to the beam coupler 2 of this embodiment, the BT50A can achieve outward projection of the principal ray La in the X direction, similar to the first embodiment.

[0124] (Other embodiments)

[0125] As described above, embodiments 1 and 2 are described as examples of the technology disclosed in this application. However, the technology disclosed in this disclosure is not limited to these embodiments and can also be applied to embodiments that have been appropriately modified, replaced, added, or omitted. In addition, the various components described in the above embodiments can be combined to form new embodiments. Therefore, other embodiments are described below.

[0126] In the above-mentioned embodiments 1 and 2, the beam coupling device 2 is described as directing the outer principal ray L1 in the Y direction inward. However, the principal ray L1 may be directed outward instead of inward. Figure 17 This modification example will be described.

[0127] Figure 17 A beam coupler 2A in this modification is shown. Figure 17 (A) and (B) respectively show a side view and a top view of the beam coupling device 2A.

[0128] The beam coupler 2A of this modification example includes Figure 2 The coupling optical system 20A is the same structure except that the cylindrical lens 22 is omitted. Figure 17 As shown in (A), in the beam coupler 2A of this modified example, the optical unit 4-1 on the outer side in the Y direction is configured to direct the principal ray L1 outward instead of inward. Such an optical unit 4-1 can be configured to direct the principal ray L1 outward, for example. Figure 10 The displacement amplitude ΔY or Figure 11 This is achieved by setting the inclination angle θi to a negative value, that is, setting it to the reverse direction.

[0129] In the beam coupling device 2A of this modification, as shown in FIG. Figure 17 As shown in (B), the intersection position P11 between the principal rays La and Lc located on the +Z side of the focal position P0 of the condenser lens 21 as the coupling optical system 20A can be used as the beam coupling position. In this case, in particular, by directing the principal ray L1 on the outer side in the Y direction outward without using the cylindrical lens 22, for example, Figure 17 As shown in (A) and (B), the beam coupler P11 in the X and Y directions can be matched.

[0130] As described above, the embodiments have been described as examples of the technology in the present disclosure, and the drawings and detailed descriptions are provided for this purpose.

[0131] Therefore, the components described in the drawings and detailed descriptions include not only components that are essential for solving the problems but also components that are not essential for illustrating the above-mentioned technology. Therefore, it should not be directly assumed that these non-essential components are essential simply because they are described in the drawings and detailed descriptions.

[0132] Furthermore, the above-described embodiments are provided to illustrate the technology of the present disclosure, and therefore various changes, substitutions, additions, omissions, and the like can be made within the scope of the claims or the scope equivalent thereto.

[0133] Industrial applicability

[0134] The present disclosure can be applied to various applications in which a plurality of light beams are coupled and used, for example, can be applied to various laser processing technologies.

Claims

1. A beam coupling device comprising: a light source comprising a plurality of light source elements arranged in a first direction and a second direction intersecting each other, wherein each light source element emits a plurality of light beams having light directions intersecting the first direction and the second direction; a plurality of optical units for guiding each light beam for each group of light source elements arranged along the first direction in the light source; as well as The coupling optical system couples multiple light beams guided by each optical unit. In the group of light source elements, relative to the light direction of the light beam from the light source element located in the center in the first direction, each optical unit makes the light direction of the light beam from the light source element located on the outer side in the first direction outward, and guides the light beam from each light source element to the coupling optical system.

2. The beam coupling device according to claim 1, wherein: The coupling optical system has a positive refractive power in the first direction that is greater than that in the second direction. Among the multiple light source elements arranged along the second direction in the light source, the multiple optical units make the light direction of the light beam from the light source element located on the outer side in the second direction inward relative to the light direction of the light beam from the light source element located in the center in the second direction.

3. The beam coupling device according to claim 2, wherein: The coupling optical system includes an axisymmetric condenser lens and a cylindrical lens having positive refractive power in the first direction.

4. The beam coupling device according to claim 3, wherein: The cylindrical lens has a focal length shorter than a distance from a position where an extension line of the principal ray of the outward light beam from the optical unit toward the light source intersects an extension line of the optical axis of the condenser lens.

5. The beam coupling device according to any one of claims 2 to 4, wherein: Each of the optical units includes a collimating lens for collimating each light beam from the group of light source elements in the second direction. Among the plurality of optical units, the collimator lenses of the optical units located on the outer sides in the second direction are arranged at positions where incident light beams are directed inward.

6. The beam coupling device according to any one of claims 2 to 4, wherein: Among the plurality of optical units, the optical units located on the outer side in the second direction are arranged so that the direction in which the light beam incident from the light source is emitted is inward.

7. The beam coupling device according to any one of claims 1 to 4, wherein: The optical unit includes a beam rotator unit for rotating each light beam from the group of light source elements. The beam rotator unit is arranged relative to the group of light source elements at a rotation angle such that the light beams from the light source elements located on the outer side in the first direction have light directions outward.

8. The beam coupling device according to any one of claims 1 to 4, wherein: The optical unit includes an optical element having a plurality of lens portions corresponding to the respective light source elements in the group of light source elements. In the optical element, the plurality of lens portions are tilted with respect to the second direction and arranged along the first direction, Of the two surfaces of the optical element, a pitch between the lens portions on the surface from which the light beams from the group of light source elements are emitted is larger than a pitch between the lens portions on the surface from which the light beams are incident.

9. A laser processing machine comprising: The beam coupling device according to any one of claims 1 to 8; and The processing head irradiates the processing object with the light beam coupled by the beam coupling device.

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