Laser device

Abstract

To provide a laser device capable of restraining deterioration of a light-emitting unit while maintaining the quality of laser light.SOLUTION: A laser device includes a light-emitting unit 41A, a first lens unit 42A, a prism unit 43A, and a second lens unit 44A. The light-emitting unit 41A includes a plurality of light-emitting regions arranged along an X-axis direction and emits a plurality of laser beams La from the plurality of light-emitting regions to one side in a Y-axis direction. The first lens unit 42A collimates the plurality of laser beams La emitted from the light-emitting unit 41A in a Z-axis direction. The prism unit 43A adjusts an arrangement direction of the plurality of laser beams La such that the plurality of laser beams La are incident on the second lens unit 44A in a state of being arranged along the Z-axis direction. The second lens unit 44A collimates the plurality of laser beams La emitted from the prism unit 43A in the X-axis direction.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a laser device. [Background technology]

[0002] Conventionally, there is known a laser device including a light-emitting unit that emits a plurality of laser beams from a plurality of light-emitting regions arranged along the slow axis direction, and a plurality of slow axis collimating lenses arranged along the slow axis direction (see, for example, Patent Document 1). In such a laser device, a slow axis collimating lens is arranged corresponding to each laser beam, and one laser beam is collimated by one slow axis collimating lens. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-108081 Summary of the Invention [Problem to be solved by the invention]

[0004] In the laser device as described above, it is important to suppress the deterioration of the light emitting unit. In order to suppress the deterioration of the light emitting unit while maintaining the output of the laser device, for example, it is possible to increase the number of light emitting regions while reducing the output of each light emitting region. However, if the number of light emitting regions is increased while suppressing the increase in size of the laser device, the width of the slow axis collimating lens will be reduced as the distance between the light emitting regions decreases, which may result in a decrease in the quality of the laser light.

[0005] An object of the present invention is to provide a laser device capable of suppressing deterioration of a light-emitting unit while maintaining the quality of laser light. [Means for solving the problem]

[0006] The laser device of the present invention includes: [1] "a laser beam emitting section having a light emitting unit including a plurality of light emitting regions arranged along a first direction and emitting a plurality of laser beams from the plurality of light emitting regions to one side of a second direction intersecting the first direction; a first lens unit arranged in an optical path of the plurality of laser beams; a prism unit arranged downstream of the optical path with respect to the first lens unit; and a second lens unit arranged downstream of the optical path with respect to the prism unit; a collecting lens arranged downstream of the optical path with respect to the laser beam emitting section; an optical fiber arranged downstream of the optical path with respect to the collecting lens; and a housing accommodating the laser beam emitting section and the collecting lens, wherein the first lens unit is a prism unit arranged downstream of the optical path with respect to the first lens unit; the prism unit adjusts an arrangement direction of the plurality of laser beams such that the plurality of laser beams emitted from the first lens unit in a state arranged along the first direction are incident on the second lens unit in a state arranged along the third direction, the second lens unit is constituted by one lens and collimates in the first direction the plurality of laser beams emitted from the prism unit in a state arranged along the third direction, and the condenser lens couples the plurality of laser beams emitted from the second lens unit to the optical fiber."

[0007] In this laser device, the prism unit adjusts the arrangement direction of the multiple laser beams so that the multiple laser beams emitted from the first lens unit in a state arranged along the first direction are incident on the second lens unit in a state arranged along the third direction, and the second lens unit collimates the multiple laser beams arranged along the third direction in the first direction. Therefore, even without reducing the width of the second lens unit in the first direction, it is possible to increase the number of light-emitting regions while reducing the distance between each light-emitting region. Therefore, according to this laser device, it is possible to suppress deterioration of the light-emitting unit while maintaining the quality of the laser beam.

[0008] The laser device of the present invention may be [2] "the laser device according to the above [1], in which the first lens unit is composed of one lens." This allows the number of parts to be reduced compared to, for example, a case in which multiple laser beams are collimated by multiple lenses.

[0009] The laser device of the present invention may be [3] "the laser device according to the above [1] or [2], wherein the prism unit has a prism that adjusts the traveling direction of at least one of the plurality of laser beams in the third direction, and a prism that adjusts the traveling direction of at least one of the plurality of laser beams in the first direction." This makes it possible to adjust the arrangement direction of the plurality of laser beams by a simple configuration of each prism.

[0010] The laser device of the present invention may be [4] "the laser device according to any one of the above [1] to [3], further comprising a support supporting the laser light emitting portion." In this way, by precisely assembling the light emitting unit, the first lens unit, the prism unit, and the second lens unit to the support, and then precisely assembling the support to the housing, it is possible to increase the precision of assembling the light emitting unit, the first lens unit, the prism unit, and the second lens unit to the housing.

[0011] The laser device of the present invention may be the laser device according to the above [4], further comprising: [5] a plurality of reflecting mirrors arranged along the first direction when viewed from the third direction, the laser light emitting unit being each of a plurality of laser light emitting units, each of the plurality of reflecting mirrors being arranged on the one side of the second direction with respect to each of the plurality of laser light emitting units, and reflecting the plurality of laser beams emitted from each of the plurality of laser light emitting units toward the condenser lens along the first direction, the support body including a plurality of mounting surfaces arranged along the first direction when viewed from the third direction and having different positions in the third direction, and the light emitting units of each of the plurality of laser light emitting units being arranged on each of the plurality of mounting surfaces. This allows the laser beams emitted from the plurality of laser light emitting units to be incident on the condenser lens in a state of being arranged along the third direction, and the optical output of the laser device can be increased.

[0012] The laser device of the present invention may be the laser device according to [6] above, "wherein the plurality of mounting surfaces are arranged in a stepped manner such that the position in the third direction increases with increasing distance from the focusing lens in the first direction." This makes it possible to increase the optical output of the laser device as described above.

[0013] The laser device of the present invention may be [7] "the laser device according to the above [5] or [6], wherein the support is fixed to the housing, and the plurality of laser light emitting units and the plurality of reflecting mirrors are fixed to the support." In this way, by precisely assembling the plurality of laser light emitting units and the plurality of reflecting mirrors to the support, and then precisely assembling the support to the housing, it is possible to improve the precision of assembling the plurality of laser light emitting units and the plurality of reflecting mirrors to the housing.

[0014] The laser device of the present invention may be [8] "the laser device according to any one of the above [4] to [7], wherein the main surface of the support includes a first region and a second region recessed from the first region, the light emitting unit is disposed in the first region, and the second lens unit is fixed to the second region by an adhesive resin." This makes it possible to suppress deterioration of the adhesive resin due to irradiation with laser light.

[0015] The laser device of the present invention may be [9] "the laser device according to the above [8], in which a fixing hole is formed in the first region." This makes it possible to suppress damage to the support, for example, when a jig or the like is fixed to the fixing hole.

[0016] The laser device of the present invention may be

[10] "the laser device according to any one of the above [4] to [9], wherein the material of the support is copper or copper tungsten." This allows heat generated in the light-emitting unit to be efficiently dissipated to the support.

[0017] The laser device of the present invention may be

[11] "the laser device according to any one of the above [1] to

[10] , further comprising a wavelength filter disposed in the optical path between the light-emitting unit and the optical fiber, which transmits the plurality of laser beams emitted from the light-emitting unit and reflects the light emitted from the optical fiber." This makes it possible to prevent light that enters the inside of the housing from the outside via the optical fiber from entering the light-emitting unit.

[0018] The laser device of the present invention may be

[12] "the laser device according to any one of the above [1] to

[11] , wherein the light-emitting unit has one semiconductor laser element including the plurality of light-emitting regions." This allows multiple laser beams to be emitted with a simple configuration.

[0019] The laser device of the present invention may be

[13] "the laser device according to any one of the above [1] to

[12] , wherein the material of the case is copper or copper tungsten." This not only allows the heat inside the case to be efficiently released to the outside of the case, but also suppresses deformation of the case due to temperature changes.

[0020] The laser device of the present invention may be

[14] "the laser device according to any one of the above [1] to

[13] , wherein the focal length of the first lens unit is 300 μm or less." This makes it possible to reduce the width in the third direction of the laser light emitted from the first lens unit and incident on the prism unit. This makes it possible to reduce the size of the prism unit.

[0021] The laser device of the present invention may be

[15] "the laser device according to any one of the above [1] to

[14] , wherein the distance between the plurality of light-emitting regions is 150 μm to 300 μm." This makes it possible to suppress optical loss while maintaining the emission shape of the laser light emitted from the light-emitting unit, and allows the laser light to be efficiently incident on the prism unit. Effect of the Invention

[0022] According to the present invention, it is possible to provide a laser device that can suppress deterioration of a light-emitting unit while maintaining the quality of laser light. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a plan view of a laser device according to an embodiment. [Diagram 2] FIG. 2 is a plan view of the support shown in FIG. [Diagram 3] FIG. 2 is a front view of the support shown in FIG. [Figure 4] FIG. 2 is a partially enlarged view of FIG. [Diagram 5] 5 is a cross-sectional view taken along line VV in FIG. 4. [Figure 6]FIG. 2 is a front view of the laser module shown in FIG. [Figure 7] FIG. 5 is a front view of the light-emitting unit shown in FIG. [Figure 8] 10A to 10C are schematic diagrams showing adjustment of the arrangement direction of a plurality of laser beams and combination of a plurality of laser beams. [Figure 9] 5 is a plan view of the first lens unit and the prism unit shown in FIG. 4. [Figure 10] 5 is a side view of the first lens unit and the prism unit shown in FIG. 4. [Figure 11] 5 is a plan view of the second lens unit and the reflecting mirror shown in FIG. 4. [Figure 12] FIG. 2 is a side view of the laser module shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In each drawing, the same or corresponding parts are denoted by the same reference numerals, and duplicated explanations will be omitted.

[0025] [Laser device configuration] As shown in FIG. 1, the laser device 1 includes a laser module 2, a condenser lens 3, an optical fiber 4, a wavelength filter 5, a housing 6, and an electrode 7. The laser device 1 is used, for example, to excite a fiber laser. The laser module 2, the condenser lens 3, and the wavelength filter 5 are housed in the housing 6 and fixed to the housing 6. The condenser lens 3 and the wavelength filter 5 are each fixed to the housing 6 by, for example, an adhesive resin. The laser module 2 emits laser light. The condenser lens 3 is disposed downstream of the optical path of the laser light with respect to the laser module 2 and condenses the laser light. The optical fiber 4 is disposed downstream of the optical path of the laser light with respect to the condenser lens 3 and propagates the laser light condensed by the condenser lens 3.

[0026] The wavelength filter 5 is disposed in the optical path between the laser module 2 and the optical fiber 4. In this embodiment, the wavelength filter 5 is disposed in the optical path between the laser module 2 and the condenser lens 3. The wavelength filter 5 suppresses the oscillation light having a wavelength different from the excitation light from entering the laser module 2. The oscillation light that enters the inside of the housing 6 from the outside of the housing 6 through the optical fiber 4 is reflected by the wavelength filter 5. The laser light (excitation light) emitted from the laser module 2 passes (transmits) through the wavelength filter 5. The wavelength filter 5 is, for example, a dichroic mirror or the like. The optical fiber 4 is connected to the housing 6. The electrode 7 is fixed to the housing 6. The laser module 2 is driven by a voltage supplied through the electrode 7. The material of the housing 6 is, for example, copper or copper tungsten.

[0027] The laser module 2 includes a support 30, a plurality of laser light emitting units 40A, 40B, 40C, and 40D, and a plurality of reflecting mirrors 50A, 50B, 50C, and 50D. The support 30 is fixed to the housing 6 by, for example, a solder material or the like. As shown in FIG. 2 and FIG. 3, the support 30 has, for example, a rectangular shape when viewed from the Z-axis direction (thickness direction of the support 30). The support 30 includes a bottom surface 31 and a main surface 32. The bottom surface 31 is a flat surface parallel to the XY plane. The main surface 32 faces the opposite side to the bottom surface 31. The main surface 32 has a stepped shape. Specifically, the main surface 32 includes a first region 33 and a second region 34. The first region 33 and the second region 34 are aligned along the Y-axis direction when viewed from the Z-axis direction. Each of the first region 33 and the second region 34 has, for example, a rectangular shape.

[0028] The first region 33 includes a base surface 33e, a first placement surface 33a, a second placement surface 33b, a third placement surface 33c, and a fourth placement surface 33d. The base surface 33e is a flat surface parallel to the XY plane. The base surface 33e has, for example, a rectangular shape. When viewed from the Z-axis direction, the first placement surface 33a, the second placement surface 33b, the third placement surface 33c, and the fourth placement surface 33d are located on the opposite side of the base surface 33e from the second region 34. Each of the first placement surface 33a, the second placement surface 33b, the third placement surface 33c, and the fourth placement surface 33d is a flat surface parallel to the XY plane. Each of the first placement surface 33a, the second placement surface 33b, the third placement surface 33c, and the fourth placement surface 33d has, for example, a rectangular shape.

[0029] The first mounting surface 33a, the second mounting surface 33b, the third mounting surface 33c, and the fourth mounting surface 33d are aligned along the X-axis direction when viewed from the Z-axis direction. The positions of the first mounting surface 33a, the second mounting surface 33b, the third mounting surface 33c, and the fourth mounting surface 33d in the Z-axis direction are different from each other. The first mounting surface 33a, the second mounting surface 33b, the third mounting surface 33c, and the fourth mounting surface 33d are aligned in a stepped manner from one side of the support 30 to the other side in the X-axis direction. The first mounting surface 33a, the second mounting surface 33b, the third mounting surface 33c, and the fourth mounting surface 33d are aligned in a stepped manner so that the positions in the Z-axis direction become higher as they move away from the focusing lens 3 in the X-axis direction (as they move toward the opposite side of the optical fiber 4 from the focusing lens 3). Specifically, the position of the first mounting surface 33a in the Z-axis direction coincides with the position of the base surface 33e in the Z-axis direction. In other words, the first mounting surface 33a is located on the same plane as the base surface 33e. The second mounting surface 33b is located on the opposite side of the bottom surface 31 with respect to the first mounting surface 33a. The third mounting surface 33c is located on the opposite side of the bottom surface 31 with respect to the second mounting surface 33b. The fourth mounting surface 33d is located on the opposite side of the bottom surface 31 with respect to the third mounting surface 33c.

[0030] The second region 34 is a flat surface parallel to the XY plane. The second region 34 is recessed from the first region 33. That is, the second region 34 is located on the bottom surface 31 side with respect to the first region 33. The second region 34 is located between the base surface 33e and the bottom surface 31 in the Z-axis direction. The distance between the bottom surface 31 and the base surface 33e is greater than the distance between the bottom surface 31 and the second region 34. That is, the thickness of the portion of the support 30 including the first region 33 is greater than the thickness of the portion of the support 30 including the second region 34.

[0031] A fixing hole 33f is formed in the base surface 33e. The fixing hole 33f penetrates, for example, the support 30. When viewed from the Z-axis direction, the fixing hole 33f has, for example, a circular shape. A jig (for example, a spacer) used for positioning the light emitting units 41A, 41B, 41C, and 41D (see FIG. 6) on the support 30 is attached to the fixing hole 33f. The material of the support 30 is, for example, copper (Cu) or copper tungsten (CuW).

[0032] The support 30 supports the laser light emitting units 40A, 40B, 40C, 40D and the reflecting mirrors 50A, 50B, 50C, 50D. The laser light emitting units 40A, 40B, 40C, 40D and the reflecting mirrors 50A, 50B, 50C, 50D are fixed to the support 30. Specifically, as shown in FIG. 4 and FIG. 5, the laser light emitting unit 40A is disposed on the main surface 32 of the support 30. The laser light emitting unit 40A has a light emitting unit 41A, a first lens unit 42A, a prism unit 43A, and a second lens unit 44A. When viewed from the Z-axis direction, the light emitting unit 41A, the first lens unit 42A, the prism unit 43A, and the second lens unit 44A are arranged in order along the Y-axis direction.

[0033] The light emitting unit 41A is disposed on the first mounting surface 33a of the support 30. The light emitting unit 41A is fixed to the support 30. Specifically, the light emitting unit 41A has one submount 411 and one semiconductor laser element 412. The submount 411 is disposed on the first mounting surface 33a. The submount 411 has a substrate formed of, for example, aluminum nitride (AIN) and a metal film (for example, Cu or Ni / Au) metallized on the surface of the substrate. The metal film functions, for example, for soldering or for conduction. The submount 411 is fixed to the first mounting surface 33a by, for example, a solder material. The semiconductor laser element 412 is disposed on the opposite side of the submount 411 from the first mounting surface 33a. The semiconductor laser element 412 is fixed to the submount 411 by, for example, a solder material. In this embodiment, the semiconductor laser element 412 includes a plurality of light emitting regions 41a (see FIG. 7). The semiconductor laser element 412 includes, for example, two light emitting regions 41a. The semiconductor laser element 412 emits a plurality of laser beams La.

[0034] The first lens unit 42A is disposed in the optical path of the plurality of laser beams La. The first lens unit 42A is disposed on the base surface 33e of the support 30. In this embodiment, the first lens unit 42A is fixed to the submount 411 by a fixing member 49A. The fixing members 49A are provided between the first lens unit 42A and the submount 411, at both ends of the first lens unit 42A in the X-axis direction. When viewed from the Z-axis direction, the fixing members 49A are located on both sides in the X-axis direction with respect to the semiconductor laser element 412. There is a gap between the first lens unit 42A and the light emitting unit 41A. The fixing members 49A are, for example, a UV curable resin.

[0035] Prism unit 43A is disposed downstream of the optical paths of the multiple laser beams La with respect to first lens unit 42A. Prism unit 43A is disposed on base surface 33e of support 30. In this embodiment, prism unit 43A is fixed to base surface 33e by, for example, a UV curable resin. Prism unit 43A may be fixed to first lens unit 42A by, for example, a UV curable resin.

[0036] The second lens unit 44A is disposed downstream of the optical paths of the multiple laser beams La with respect to the prism unit 43A. The second lens unit 44A is disposed on the second region 34 of the support body 30. The second lens unit 44A is fixed to the support body 30. The second lens unit 44A is fixed to the second region 34 by, for example, an adhesive resin 8. The adhesive resin 8 is located closer to the bottom surface 31 than the first region 33.

[0037] The reflecting mirror 50A is disposed downstream of the optical path of the plurality of laser beams La with respect to the second lens unit 44A. The reflecting mirror 50A is disposed in the optical path between the second lens unit 44A and the condenser lens 3 (see FIG. 1). The reflecting mirror 50A is disposed on the second region 34. The reflecting mirror 50A is fixed to the support body 30. The reflecting mirror 50A is fixed to the second region 34 by, for example, an adhesive resin 9. The adhesive resin 9 is located closer to the bottom surface 31 than the first region 33.

[0038] As shown in FIG. 6, the laser light emitting units 40A, 40B, 40C, and 40D are arranged along the X-axis direction. The laser light emitting unit 40B has a light emitting unit 41B, a first lens unit 42B, a prism unit 43B, and a second lens unit 44B, similar to the laser light emitting unit 40A. The laser light emitting unit 40B is different from the laser light emitting unit 40A in that the light emitting unit 41B is disposed on the second mounting surface 33b. The laser light emitting unit 40C has a light emitting unit 41C, a first lens unit 42C, a prism unit 43C, and a second lens unit 44C, similar to the laser light emitting unit 40A. The laser light emitting unit 40C is different from the laser light emitting unit 40A in that the light emitting unit 41C is disposed on the third mounting surface 33c. Similar to the laser light emitting unit 40A, the laser light emitting unit 40D has a light emitting unit 41D, a first lens unit 42D, a prism unit 43D, and a second lens unit 44D. The laser light emitting unit 40D differs from the laser light emitting unit 40A in that the light emitting unit 41D is disposed on the fourth mounting surface 33d.

[0039] The configuration of each of the light-emitting units 41B, 41C, and 41D is the same as the configuration of the light-emitting unit 41A. The configuration of each of the first lens units 42B, 42C, and 42D is the same as the configuration of the first lens unit 42A. The configuration of each of the prism units 43B, 43C, and 43D is the same as the configuration of the prism unit 43A. The configuration of each of the second lens units 44B, 44C, and 44D is the same as the configuration of the second lens unit 44A.

[0040] As shown in FIG. 1 and FIG. 6, the reflection mirror 50A is disposed on one side in the Y-axis direction with respect to the laser light emitting section 40A. The reflection mirror 50B is disposed on one side in the Y-axis direction with respect to the laser light emitting section 40B. The reflection mirror 50C is disposed on one side in the Y-axis direction with respect to the laser light emitting section 40C. The reflection mirror 50D is disposed on one side in the Y-axis direction with respect to the laser light emitting section 40D. The multiple reflection mirrors 50A, 50B, 50C, and 50D are aligned along the X-axis direction when viewed from the Z-axis direction. With this configuration, it is possible to prevent the laser device 1 from becoming large.

[0041] The height (length in the Z-axis direction) of the reflecting mirror 50B is greater than the height of the reflecting mirror 50A. An end 50b of the reflecting mirror 50B opposite to the support 30 is located on the opposite side to the support 30 from an end 50a of the reflecting mirror 50A opposite to the support 30. The difference between the heights of the reflecting mirror 50B and the reflecting mirror 50A is approximately the same as the difference between the heights of the second mounting surface 33b and the first mounting surface 33a. The height of the reflecting mirror 50C is greater than the height of the reflecting mirror 50B. An end 50c of the reflecting mirror 50C opposite to the support 30 is located on the opposite side to the support 30 from an end 50b of the reflecting mirror 50B opposite to the support 30. The difference between the heights of the reflecting mirror 50C and the reflecting mirror 50B is approximately the same as the difference between the heights of the third mounting surface 33c and the second mounting surface 33b. The height of the reflecting mirror 50D is greater than the height of the reflecting mirror 50C. An end 50d of the reflecting mirror 50D opposite to the support 30 is located on the opposite side from the support 30 than an end 50c of the reflecting mirror 50C opposite to the support 30. The difference in height between the reflecting mirror 50D and the reflecting mirror 50C is approximately the same as the difference in height between the fourth mounting surface 33d and the third mounting surface 33c. The configuration of each of the reflecting mirrors 50B, 50C, and 50D is the same as the configuration of the reflecting mirror 50A except for the height.

[0042] [Collimation of multiple laser beams and adjustment of array direction] As shown in FIG. 7, the semiconductor laser element 412 includes a plurality of light-emitting regions 41a. In this embodiment, the semiconductor laser element 412 includes two light-emitting regions 41a. The plurality of light-emitting regions 41a are arranged along the X-axis direction (first direction). The distance (center-to-center distance) W between adjacent light-emitting regions 41a is, for example, 150 μm to 300 μm. A plurality of laser beams La are emitted from the plurality of light-emitting regions 41a. The laser beam La has a fast axis direction in the Z-axis direction and a slow axis direction in the X-axis direction.

[0043] As shown in FIG. 8, the plurality of laser beams La emitted from the light-emitting unit 41A in a state of being arranged along the X-axis direction are emitted from the second lens unit 44A in a state of being arranged along the Z-axis direction, and then are reflected by the reflection mirror 50A. The light-emitting unit 41B emits a plurality of laser beams Lb arranged along the X-axis direction, similar to the light-emitting unit 41A. The plurality of laser beams Lb are emitted from the second lens unit 44B in a state of being arranged along the Z-axis direction, similar to the plurality of laser beams La, and then are reflected by the reflection mirror 50B. The light-emitting unit 41C emits a plurality of laser beams Lc arranged along the X-axis direction, similar to the light-emitting unit 41A. The plurality of laser beams Lc are emitted from the second lens unit 44C in a state of being arranged along the Z-axis direction, similar to the plurality of laser beams La, and then are reflected by the reflection mirror 50C. The light-emitting unit 41D emits a plurality of laser beams Ld arranged along the X-axis direction, similar to the light-emitting unit 41A. The multiple laser beams Ld are emitted from the second lens unit 44D in a state where they are arranged along the Z-axis direction, similar to the multiple laser beams La, and are then reflected by the reflecting mirror 50D. The multiple laser beams La, the multiple laser beams Lb, the multiple laser beams Lc, and the multiple laser beams Ld are incident on the collecting lens 3 in a state where they are arranged along the Z-axis direction, and are collected as one laser beam L by the collecting lens 3.

[0044] Next, focusing on the laser light emitting unit 40A, the collimation of the multiple laser lights La and the adjustment of the arrangement direction will be described in detail. In Fig. 9 to Fig. 11, one laser light La is shown as laser light La1, and the other laser light La is shown as laser light La2. Note that the fixing member 49A is omitted from Fig. 9 and Fig. 10.

[0045] 9 and 10, the light-emitting unit 41A emits a plurality of laser beams La (laser beams La1 and La2) arranged along the X-axis direction toward one side (arrow D) in the Y-axis direction (second direction). Each of the laser beams La1 and La2 is, for example, a diverging beam. Each of the laser beams La1 and La2 travels along the Y-axis direction while diverging in a cone shape as it moves away from the light-emitting unit 41A.

[0046] The first lens unit 42A collimates the laser light La1 and the laser light La2 emitted from the light emitting unit 41A in a Z-axis direction (third direction) that intersects (is perpendicular to) both the X-axis direction and the Y-axis direction while being arranged along the X-axis direction. Specifically, the first lens unit 42A is, for example, a cylindrical lens whose collimation direction is the Z-axis direction. The first lens unit 42A is, for example, a first-axis collimating lens made of high-refractive index glass. The first lens unit 42A extends along the X-axis direction.

[0047] The first lens unit 42A includes an incident surface 421 facing the multiple light-emitting regions 41a of the light-emitting unit 41A, and an exit surface 422 facing the opposite side to the incident surface 421. The incident surface 421 is, for example, a flat surface parallel to the XZ plane. The exit surface 422 is a convex surface protruding on the opposite side to the incident surface 421. The exit surface 422 is a part of a cylindrical surface having an axis parallel to the X-axis direction. The laser light La1 and the laser light La2 that are incident on the incident surface 421 while diffusing in a cone shape are collimated (parallelized) in the Z-axis direction by the first lens unit 42A, and then are emitted from the exit surface 422 as light parallel to the XY plane, for example. The width of the first lens unit 42A in the Z-axis direction is, for example, smaller than 1 mm. The width of the first lens unit 42A in the Z-axis direction is, for example, about 0.6 mm. The focal length of the first lens unit 42A is, for example, 300 μm or less.

[0048] Prism unit 43A adjusts the arrangement direction of laser beam La1 and laser beam La2 so that laser beam La1 and laser beam La2 emitted from first lens unit 42A while being arranged along the X-axis direction are incident on second lens unit 44A (see FIG. 11) while being arranged along the Z-axis direction. Specifically, prism unit 43A has a first prism 46A, a second prism 47A, and a third prism 48A.

[0049] The first prism 46A is disposed in the optical path of the laser light La1. The first prism 46A adjusts the traveling direction of the laser light La1 in the Z-axis direction. The first prism 46A includes an incident surface 461 facing the exit surface 422 of the first lens unit 42A, and an exit surface 462 facing the opposite side to the incident surface 461. Each of the incident surface 461 and the exit surface 462 is, for example, a flat surface parallel to the XZ plane. The exit surface 462 is located closer to the support 30 side than the incident surface 461. The laser light La1 incident on the incident surface 461 passes through the first prism 46A toward the exit surface 462, and then is emitted from the exit surface 462. The first prism 46A is not disposed in the optical path of the laser light La2. That is, the laser light La2 does not pass through the first prism 46A.

[0050] The second prism 47A is disposed in the optical path of the laser light La1. The second prism 47A includes an incident surface 471 facing the exit surface 462 of the first prism 46A, and an exit surface 472 facing the opposite side to the incident surface 471. Each of the incident surface 471 and the exit surface 472 is, for example, a flat surface parallel to the XZ plane. The exit surface 472 overlaps with the incident surface 471 when viewed from the Y-axis direction. The laser light La1 incident on the incident surface 471 passes through the second prism 47A toward the exit surface 472, and is then emitted from the exit surface 472. The second prism 47A is not disposed in the optical path of the laser light La2. That is, the laser light La2 does not pass through the second prism 47A.

[0051] The third prism 48A is disposed in the optical path of the laser light La2. The third prism 48A adjusts the traveling direction of the laser light La2 in the X-axis direction. The third prism 48A is disposed on the opposite side of the support 30 with respect to the second prism 47A. The third prism 48A includes an incident surface 481 that faces obliquely toward the exit surface 422 of the first lens unit 42A, and an exit surface 482 that faces the opposite side to the incident surface 481. The incident surface 481 is parallel to the Z-axis direction and obliquely intersects with each of the X-axis direction and the Y-axis direction. When viewed from the Z-axis direction, the incident surface 481 is inclined so as to move away from the laser light La1 as it moves away from the light-emitting unit 41A along the Y-axis direction.

[0052] The laser light La2 incident on the incident surface 481 is refracted by the incident surface 481 and then passes through the third prism 48A so as to approach the laser light La1 in the X-axis direction. The laser light La2 is refracted by the exit surface 482 and then emitted from the exit surface 482 along the Y-axis direction. When viewed from the Z-axis direction, the laser light La2 emitted from the exit surface 482 travels along the Y-axis direction while overlapping with the laser light La1 passing through the second prism 47A. When viewed from the Z-axis direction, the spread angle of the laser light La2 emitted from the exit surface 482 is approximately the same as the spread angle of the laser light La1 passing through the second prism 47A. The third prism 48A is not disposed in the optical path of the laser light La1. That is, the laser light La1 does not pass through the third prism 48A. As described above, the laser beam La1 and the laser beam La2 that are incident on the prism unit 43A while being aligned along the X-axis direction are emitted from the prism unit 43A while being aligned along the Z-axis direction.

[0053] As shown in Fig. 11, the second lens unit 44A collimates the laser light La1 and the laser light La2 emitted from the prism unit 43A in the X-axis direction while being arranged along the Z-axis direction. Specifically, the second lens unit 44A is, for example, a cylindrical lens whose collimation direction is the X-axis direction. The second lens unit 44A is, for example, a slow-axis collimating lens made of high-refractive index glass. The second lens unit 44A extends along the Z-axis direction. When viewed from the Y-axis direction, the second lens unit 44A overlaps with the prism unit 43A.

[0054] The second lens unit 44A includes an incident surface 441 facing the prism unit 43A, and an exit surface 442 facing the opposite side to the incident surface 441. The incident surface 441 is, for example, a flat surface parallel to the XZ plane. The exit surface 442 is a convex surface protruding on the opposite side to the incident surface 441. The exit surface 442 is a part of a cylindrical surface having an axis parallel to the Z axis direction. The laser light La1 and the laser light La2 incident on the incident surface 441 are collimated (parallelized) in the X axis direction by the second lens unit 44A, and then emitted from the exit surface 442 as parallel light (collimated light) parallel to, for example, the Y axis direction.

[0055] The width of second lens unit 44A in the X-axis direction is greater than the distance W (see FIG. 7) between light-emitting regions 41a of light-emitting unit 41A. The width of second lens unit 44A in the X-axis direction is, for example, 1 mm or more. In this embodiment, the width of second lens unit 44A in the X-axis direction is, for example, about 3 mm. The focal length of second lens unit 44A is, for example, about 5.6 mm.

[0056] The reflecting mirror 50A reflects the laser beam La1 and the laser beam La2 emitted from the second lens unit 44A along the X-axis direction toward the condenser lens 3 (see FIG. 1). The reflecting mirror 50A includes a reflecting surface 51 that faces the second lens unit 44A obliquely. The reflecting surface 51 is parallel to the Z-axis direction and obliquely intersects with the X-axis direction and the Y-axis direction. When viewed from the Z-axis direction, the reflecting surface 51 is inclined so as to approach the condenser lens 3 along the Y-axis direction as it moves away from the second lens unit 44A. In this embodiment, "along a direction" includes a form parallel to the direction and a form intersecting with the direction at a predetermined angle. The predetermined angle is, for example, 0 degrees to 30 degrees. In this embodiment, the reflection mirror 50A may reflect the laser light La1 and the laser light La2 emitted from the second lens unit 44A so that the laser light La1 and the laser light La2 travel along an optical path parallel to the X-axis direction, or may reflect the laser light La1 and the laser light La2 emitted from the second lens unit 44A so that the laser light La1 and the laser light La2 travel along an optical path that intersects with the X-axis direction at the above-mentioned specified angle.

[0057] As shown in FIG. 12, the laser beams La (laser beam La1 and laser beam La2) are emitted from the second lens unit 44A in a state of being arranged along the Z-axis direction, and are then reflected by the reflecting mirror 50A in a state of being arranged along the Z-axis direction. The laser beams Lb, like the laser beams La, are emitted from the second lens unit 44B in a state of being arranged along the Z-axis direction, and are then reflected by the reflecting mirror 50B in a state of being arranged along the Z-axis direction. The laser beams Lb are reflected at a position on the opposite side of the support 30 with respect to the reflecting mirror 50A. That is, the laser beams Lb do not pass through the reflecting mirror 50A. The laser beams Lc, like the laser beams La, are emitted from the second lens unit 44C in a state of being arranged along the Z-axis direction, and are then reflected by the reflecting mirror 50C in a state of being arranged along the Z-axis direction. The laser beams Lc are reflected at a position on the opposite side of the support 30 with respect to the reflecting mirror 50B. That is, the laser beams Lc do not pass through the reflecting mirror 50B and the reflecting mirror 50A. The multiple laser beams Ld are emitted from the second lens unit 44D in a state of being arranged along the Z-axis direction, similar to the multiple laser beams La, and are then reflected by the reflecting mirror 50D in a state of being arranged along the Z-axis direction. The multiple laser beams Ld are reflected at a position on the opposite side of the support 30 with respect to the reflecting mirror 50C. In other words, the multiple laser beams Ld do not pass through the reflecting mirror 50C, the reflecting mirror 50B, and the reflecting mirror 50A. As described above, the multiple laser beams La, the multiple laser beams Lb, the multiple laser beams Lc, and the multiple laser beams Ld are incident on the focusing lens 3 (see FIG. 1) in a state of being arranged along the Z-axis direction.

[0058] The condenser lens 3 condenses the plurality of laser beams La, the plurality of laser beams Lb, the plurality of laser beams Lc, and the plurality of laser beams Ld, and then couples the condensed laser beams to an optical fiber 4 (see FIG. 1).

[0059] [Action and Effects] As described above, in the laser device 1, the prism unit 43A adjusts the arrangement direction of the laser beams La so that the laser beams La emitted from the first lens unit 42A in a state of being arranged along the X-axis direction are incident on the second lens unit 44A in a state of being arranged along the Z-axis direction, and the second lens unit 44A collimates the laser beams La arranged along the Z-axis direction in the X-axis direction. Therefore, even if the width of the second lens unit 44A in the X-axis direction is not reduced, the number of the light-emitting regions 41a can be increased while reducing the distance W between the light-emitting regions 41a. Therefore, according to the laser device 1, the deterioration of the light-emitting unit 41A can be suppressed while maintaining the quality of the laser beams La emitted from the second lens unit 44A. When the width of the second lens unit 44A in the X-axis direction is reduced, for example, it tends to be difficult to ensure the accuracy of the shape of the emission surface 442 of the second lens unit 44A, so that the quality of the laser beams La collimated by the second lens unit 44A may be reduced. Furthermore, when the width of the second lens unit 44A in the X-axis direction is reduced, a part of the laser light La may not be incident on the second lens unit 44A, and in that case, the quality of the laser light La may be degraded. In this embodiment, as described above, it is not necessary to reduce the width of the second lens unit 44A in the X-axis direction, so that the quality of the laser light La can be maintained. In addition, by increasing the number of light-emitting regions 41a, the output of each light-emitting region 41a can be reduced while maintaining the output of the laser device 1, and deterioration of the light-emitting unit 41A caused by the return light from the optical fiber 4 can be suppressed.

[0060] The second lens unit 44A is composed of one lens whose collimation direction is the X-axis direction. This allows the multiple laser lights La arranged along the Z-axis direction to be collimated in the X-axis direction by one lens, and the number of parts can be reduced compared to the case where the multiple laser lights La are collimated by multiple lenses. This effect is achieved because the arrangement direction of the multiple laser lights La is adjusted by the prism unit 43A as described above. In other words, the second lens unit 44A composed of one lens can be adopted because the arrangement direction of the multiple laser lights La is adjusted by the prism unit 43A. On the other hand, for example, when the arrangement direction of the multiple laser lights La is not adjusted, that is, when the multiple laser lights La are collimated in the X-axis direction while being arranged along the X-axis direction, it is necessary to adopt a configuration in which multiple collimating lenses whose collimation direction is the X-axis direction are arranged along the X-axis direction.

[0061] The first lens unit 42A is composed of a single lens whose collimation direction is the Z-axis direction. This allows the single lens to collimate the multiple laser beams La arranged along the X-axis direction in the Z-axis direction, and the number of parts can be reduced compared to, for example, a case in which multiple laser beams La are collimated by multiple lenses.

[0062] The prism unit 43A has a first prism 46A that adjusts the traveling direction of the laser light La1 in the Z-axis direction, and a third prism 48A that adjusts the traveling direction of the laser light La2 in the X-axis direction. With this, the arrangement directions of the laser light La1 and the laser light La2 can be adjusted by the simple configuration of the first prism 46A and the third prism 48A.

[0063] The laser device 1 includes a support 30 that supports the laser light emitting unit 40A. This allows the laser light emitting unit 40A to be appropriately supported. Moreover, by precisely assembling the light emitting unit 41A, the first lens unit 42A, the prism unit 43A, and the second lens unit 44A to the support 30, and then precisely assembling the support 30 to the housing 6, the precision with which the light emitting unit 41A, the first lens unit 42A, the prism unit 43A, and the second lens unit 44A are assembled to the housing 6 can be improved.

[0064] The laser device 1 includes a plurality of reflecting mirrors 50A, 50B, 50C, and 50D arranged along the X-axis direction when viewed from the Z-axis direction. Each of the reflecting mirrors 50A, 50B, 50C, and 50D is disposed on one side in the Y-axis direction with respect to each of the laser light emitting units 40A, 40B, 40C, and 40D. The reflecting mirror 50A reflects the plurality of laser lights La emitted from the laser light emitting unit 40A toward the condenser lens 3 along the X-axis direction, the reflecting mirror 50B reflects the plurality of laser lights Lb emitted from the laser light emitting unit 40B toward the condenser lens 3 along the X-axis direction, the reflecting mirror 50C reflects the plurality of laser lights Lc emitted from the laser light emitting unit 40C toward the condenser lens 3 along the X-axis direction, and the reflecting mirror 50D reflects the plurality of laser lights Ld emitted from the laser light emitting unit 40D toward the condenser lens 3 along the X-axis direction. The support 30 includes a plurality of mounting surfaces 33a, 33b, 33c, and 33d that are aligned along the X-axis direction when viewed from the Z-axis direction and that are located at different positions in the Z-axis direction. The light-emitting units 41A, 41B, 41C, and 41D are disposed on the mounting surfaces 33a, 33b, 33c, and 33d, respectively. This allows the laser beams La, Lb, Lc, and Ld emitted from the laser beam emitters 40a, 40b, 40c, and 40d to be incident on the condenser lens 3 while being aligned along the Z-axis direction, thereby increasing the optical output of the laser device 1.

[0065] The first mounting surface 33a, the second mounting surface 33b, the third mounting surface 33c, and the fourth mounting surface 33d are arranged in a stepped manner such that the position in the Z-axis direction increases as the surface moves away from the condenser lens 3 in the X-axis direction. This allows the optical output of the laser device 1 to be increased as described above. In addition, the laser light Lb reflected by the reflecting mirror 50B enters the condenser lens 3 without passing through the reflecting mirror 50A, the laser light Lc reflected by the reflecting mirror 50C enters the condenser lens 3 without passing through the reflecting mirrors 50B and 50A, and the laser light Ld reflected by the reflecting mirror 50D enters the condenser lens 3 without passing through the reflecting mirrors 50C, 50B, and 50A, thereby suppressing losses of the laser lights Lb, Lc, and Ld.

[0066] The support 30 is fixed to the housing 6, and the multiple laser light emitting units 40A, 40B, 40C, 40D and the multiple reflecting mirrors 50A, 50B, 50C, 50D are fixed to the support 30. Thereby, by precisely assembling the multiple laser light emitting units 40A, 40B, 40C, 40D and the multiple reflecting mirrors 50A, 50B, 50C, 50D to the support 30, and then precisely assembling the support 30 to the housing 6, it is possible to improve the assembling accuracy of the multiple laser light emitting units 40A, 40B, 40C, 40D and the multiple reflecting mirrors 50A, 50B, 50C, 50D to the housing 6.

[0067] A main surface 32 of the support 30 includes a first region 33 and a second region 34 that is recessed from the first region 33. The light emitting unit 41A is disposed in the first region 33, and the second lens unit 44A is fixed to the second region 34 by an adhesive resin 8. This makes it possible to suppress deterioration of the adhesive resin 8 due to irradiation with the laser light La.

[0068] A fixing hole 33f is formed in the first region 33. This makes it possible to prevent damage to the support 30 when, for example, a jig or the like is fixed in the fixing hole 33f.

[0069] The material of the support 30 is copper or copper tungsten, which allows heat generated in the light emitting unit 41A to be efficiently dissipated to the support 30.

[0070] The laser device 1 includes a wavelength filter 5 disposed in an optical path between the light-emitting unit 41A and the optical fiber 4. The wavelength filter 5 transmits a plurality of laser beams La emitted from the light-emitting unit 41A and reflects light emitted from the optical fiber 4. This makes it possible to prevent light that has entered the inside of the housing 6 from the outside via the optical fiber 4 from entering the light-emitting unit 41A.

[0071] The light emitting unit 41A has one semiconductor laser element including a plurality of light emitting regions 41a, which makes it possible to emit a plurality of laser beams La with a simple configuration.

[0072] The material of the housing 6 is copper or copper tungsten, which not only allows the heat inside the housing 6 to be efficiently released to the outside of the housing 6, but also makes it possible to suppress deformation of the housing 6 due to temperature changes.

[0073] The focal length of first lens unit 42A is 300 μm or less. This makes it possible to reduce the width in the Z-axis direction of laser light La emitted from first lens unit 42A and incident on prism unit 43A. This makes it possible to reduce the size of prism unit 43A.

[0074] The distance W between each of the light-emitting regions 41a is 150 μm to 300 μm. This makes it possible to suppress optical loss while maintaining the emission shape of the laser light La emitted from the light-emitting unit 41A, and allows the laser light La to be efficiently incident on the prism unit 43A.

[0075] The above-mentioned functions and effects of the laser light output unit 40A are similarly exhibited in the laser light output units 40B, 40C, and 40D.

[0076] [Variations] The present invention is not limited to the above-described embodiments.

[0077] In the embodiment, the laser module 2 has a plurality of laser light emitting parts 40A, 40B, 40C, and 40D, but the laser module 2 may have at least one of the plurality of laser light emitting parts 40A, 40B, 40C, and 40D. In the embodiment, one semiconductor laser element 412 includes two light emitting regions 41a, but one semiconductor laser element 412 may include three or more light emitting regions 41a. In the embodiment, the light emitting unit 41A has one semiconductor laser element 412, but the light emitting unit 41A may have a plurality of semiconductor laser elements arranged along, for example, the X-axis direction. In this case, each semiconductor laser element may include a plurality of light emitting regions 41a arranged along the X-axis direction, or may include one light emitting region 41a. It is only necessary that the plurality of laser beams La arranged along the Z direction are collimated in the X-axis direction by the second lens unit 44A.

[0078] In the embodiment, the light-emitting unit 41A has the submount 411, but the light-emitting unit 41A does not have to have the submount 411. In this case, the semiconductor laser element 412 of the light-emitting unit 41A may be fixed to the support 30 by, for example, a solder material or the like.

[0079] In the embodiment, the first lens unit 42A is configured by one cylindrical lens, but the first lens unit 42A may be a lens array having a plurality of collimating lenses arranged along the X-axis direction and collimating in the Z-axis direction, for example. In this case, one collimating lens may collimate one laser light La.

[0080] In the embodiment, the prism unit 43A has the first prism 46A, the second prism 47A, and the third prism 48A, but the prism unit 43A may be composed of one or two prisms, or may have four or more prisms. In the embodiment, the traveling direction of the laser light La1 is adjusted in the Z-axis direction, and the traveling direction of the laser light La2 is adjusted in the X-axis direction, but the traveling direction of either the laser light La1 or the laser light La2 may be adjusted in both the Z-axis direction and the X-axis direction. It is sufficient that the prism unit 43A adjusts the arrangement direction of the multiple laser lights La from the X-axis direction to the Z-axis direction.

[0081] In the embodiment, the reflecting mirrors 50A, 50B, 50C, and 50D are fixed to the support 30. However, the reflecting mirrors 50A, 50B, 50C, and 50D may be fixed to the housing 6, for example.

[0082] In the embodiment, the laser device 1 is used for exciting a fiber laser, but the laser device 1 may also be used for, for example, laser processing. [Explanation of symbols]

[0083] 1...laser device, 3...condensing lens, 4...optical fiber, 5...wavelength filter, 6...housing, 8...adhesive resin, 30...support, 32...main surface, 33...first region, 33f...fixing hole, 34...second region, 40A, 40B, 40C, 40D...laser light emitting portion, 41a...light emitting region, 41A, 41B, 41C, 41D...light emitting unit, 42A, 42B, 42C, 42D...first lens unit, 43A, 43B, 43C, 43D...prism unit, 44A, 44B, 44C, 44D...second lens unit, 50A, 50B, 50C, 50D...reflecting mirror, La, Lb, Lc, Ld, La1, La2...laser light.

Claims

1. a laser light emitting unit including a light emitting unit including a plurality of light emitting regions arranged along a first direction and emitting a plurality of laser beams from the plurality of light emitting regions to one side of a second direction intersecting the first direction, a first lens unit disposed in an optical path of the plurality of laser beams, a prism unit disposed downstream of the optical path with respect to the first lens unit, and a second lens unit disposed downstream of the optical path with respect to the prism unit; a condenser lens disposed downstream of the optical path with respect to the laser light output unit; an optical fiber disposed downstream of the optical path with respect to the focusing lens; a housing that houses the laser light emitting unit and the condenser lens, the first lens unit collimates the plurality of laser beams emitted from the light-emitting units in a state where the plurality of laser beams are arranged along the first direction, in a third direction intersecting both the first direction and the second direction; the prism unit adjusts an arrangement direction of the plurality of laser beams such that the plurality of laser beams emitted from the first lens unit while being arranged along the first direction are incident on the second lens unit while being arranged along the third direction; the second lens unit is configured with one lens, and collimates, in the first direction, the plurality of laser beams emitted from the prism unit while being arranged along the third direction; The focusing lens couples the multiple laser beams emitted from the second lens unit into the optical fiber.

2. The laser device according to claim 1 , wherein the first lens unit is constituted by a single lens.

3. 2. The laser device according to claim 1, wherein the prism unit includes a prism that adjusts a propagation direction of one of the plurality of laser beams in the third direction, and a prism that adjusts a propagation direction of one of the plurality of laser beams in the first direction.

4. The laser device according to claim 1 , further comprising a support body for supporting the laser light emitting portion.

5. Further comprising a plurality of reflecting mirrors aligned along the first direction when viewed from the third direction, the laser light output unit is each of a plurality of laser light output units, each of the plurality of reflection mirrors is disposed on one side of each of the plurality of laser light emitting units in the second direction, and reflects the plurality of laser light emitted from each of the plurality of laser light emitting units toward the condenser lens along the first direction; the support body includes a plurality of mounting surfaces that are aligned along the first direction when viewed from the third direction and that are positioned differently from one another in the third direction, The laser device according to claim 4 , wherein the light emitting units of the plurality of laser light emitting sections are disposed on the plurality of mounting surfaces, respectively.

6. The laser device according to claim 5 , wherein the plurality of mounting surfaces are arranged in a stepped manner such that the positions in the third direction become higher as the mounting surfaces are spaced apart from the focusing lens in the first direction.

7. The support is fixed to the housing, The laser device according to claim 5 , wherein the plurality of laser light emitting portions and the plurality of reflecting mirrors are fixed to the support body.

8. The main surface of the support includes a first region and a second region recessed relative to the first region, The light emitting unit is disposed in the first region, The laser device according to claim 4 , wherein the second lens unit is fixed to the second region by an adhesive resin.

9. The laser device according to claim 8 , wherein the first region is formed with a fixing hole.

10. 5. The laser device of claim 4, wherein the material of the support is copper or copper tungsten.

11. 2. The laser device according to claim 1, further comprising a wavelength filter disposed in the optical path between the light-emitting unit and the optical fiber, the wavelength filter transmitting the plurality of laser beams emitted from the light-emitting unit and reflecting the light emitted from the optical fiber.

12. The laser device according to claim 1 , wherein the light-emitting unit has one semiconductor laser element including the plurality of light-emitting regions.

13. The laser device of claim 1 , wherein the material of the housing is copper or copper tungsten.

14. The laser device of claim 1 , wherein the first lens unit has a focal length of 300 μm or less.

15. 2. The laser device according to claim 1, wherein the distance between the plurality of light emitting regions is 150 μm to 300 μm.

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