Light source device

Abstract

This light source device comprises: a first light source; a plurality of first cylindrical lenses; a light beam merging part disposed to transmit portion of light from the plurality of first cylindrical lenses and reflect the rest, thereby narrowing the width in a first direction of a luminous flux emitted from the first light source; and a light condensing lens that condenses light emitted from the light beam merging part. The first light source has a first row of a plurality of light emitting elements disposed side by side in the first direction, and a plurality of collimator lens parts disposed to respectively correspond to the first row of the plurality of light emitting elements. Each of the first row of the plurality of light emitting elements has a first emitter that emits first light and a second emitter that emits second light, and each of the plurality of collimator lens parts transmits the first light and second light. The plurality of first cylindrical lenses are disposed to respectively correspond to the first row of the plurality of light emitting elements, and collimate the first light and the second light emitted from the first light source.

Description

[Technical Field]

[0001] The present invention relates to a light source device having an emitter that emits light. [Background technology]

[0002] Conventionally, there are light source devices that input light into optical fibers. Optical fibers are used, for example, as light guide members in endoscope systems and projectors. The light emitted from the optical fiber can be used to capture clear images of affected areas or project bright images.

[0003] For example, in the fiber light source of Patent Document 1, blue and green laser light is emitted from a solid-state light source, part of the green light is converted into red phosphor light by a wavelength conversion element, and white light is generated by combining the blue, green, and red lights. The generated white light is input into an optical fiber. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-138992 Summary of the Invention

[0005] However, in recent years, there has been a demand for an increase in the amount of white light. When using laser light as a light source for red light, it is not possible to ensure a sufficient amount of light with laser light from a single emitter, and when the number of emitters is increased, the diameter of the light beam increases, making it impossible to sufficiently focus the light into an optical fiber, making it difficult to obtain high-output light.

[0006] Furthermore, when white light, which is laser light plus phosphor light, is input into an optical fiber, as in the technology described in Patent Document 1, the coupling efficiency to the optical fiber decreases and a portion of the white light is lost. Therefore, when high-power white light is input into an optical fiber, the end face of the optical fiber may be damaged by the heating light that cannot enter the optical fiber.

[0007] An object of the present disclosure is to provide a light source device that improves the coupling efficiency of light incident on an optical fiber, and that achieves both suppression of damage to the optical fiber and transmission of high-power light.

[0008] The light source device according to the present disclosure includes a first light source, a plurality of first cylindrical lenses, a beam merging unit arranged to narrow the width of the light beam emitted from the first light source in a first direction by transmitting a portion of the light from the plurality of first cylindrical lenses and reflecting the remainder, and a condensing lens that condenses the light emitted from the beam merging unit. The first light source includes a first row of light-emitting elements arranged in the first direction and a plurality of collimating lens units arranged corresponding to the first row of light-emitting elements, each of which has a first emitter that emits first light and a second emitter that emits second light, and each of the plurality of collimating lens units transmits the first light and the second light. The plurality of first cylindrical lenses are arranged corresponding to the first row of light-emitting elements, each of which collimates the first light and the second light emitted from the first light source.

[0009] The present disclosure can provide a light source device that improves the coupling efficiency of light incident on an optical fiber, and that achieves both suppression of damage to the optical fiber and transmission of high-power light. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view showing a configuration of a light source device according to a first embodiment. [Figure 2] FIG. 1 is a plan view showing a configuration of a light source device according to a first embodiment. [Figure 3] FIG. 1 is an enlarged plan view of a first light source according to the first embodiment; [Figure 4] FIG. 1 is an explanatory diagram illustrating the collimation of light from a first light source according to the first embodiment; [Figure 5] 1 is an enlarged side view of the periphery of a first light source unit according to the first embodiment; [Figure 6] FIG. 1 is an explanatory diagram showing the configuration of a light beam merging unit according to the first embodiment; [Figure 7] FIG. 1 is a side view showing a configuration of a light source device according to a first embodiment. [Figure 8] FIG. 10 is a plan view showing the configuration of a light source device according to a second embodiment. [Figure 9] FIG. 10 is a perspective view showing the appearance of a first light source according to a second embodiment; [Figure 10] FIG. 10 is an explanatory diagram illustrating the collimation of light from a first light source according to the second embodiment. [Figure 11] FIG. 10 is an explanatory diagram showing the configuration of a light beam merging unit according to a second embodiment; [Figure 12] FIG. 10 is a plan view showing the configuration of a light source device according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. However, more detailed explanation than necessary may be omitted. For example, detailed explanation of well-known matters or redundant explanation of substantially the same configuration may be omitted. This is to avoid unnecessary redundancy in the following explanation and to facilitate understanding by those skilled in the art.

[0012] The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0013] (Embodiment 1) [1-1. Configuration of the light source device] A light source device 1 according to a first embodiment will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is a perspective view showing the configuration of the light source device 1 according to the embodiment. Fig. 2 is a plan view of the light source device 1. Fig. 3 is an enlarged plan view of a first light source 3.

[0014] The light source device 1 includes a first light source 3, a second light source 5, a third light source 7, a dichroic mirror 33, and a condenser lens 9. The first light source 3 emits red laser light, the second light source 5 emits green laser light, and the third light source 7 emits blue laser light. The dichroic mirror 33 transmits the red laser light and reflects the blue and green laser lights, thereby combining the red, blue, and green laser lights to generate white light. An end 35a of an optical fiber 35 is located at or near a focal position 9a of the condenser lens 9, and the white light emitted from the dichroic mirror 33 is condensed by the condenser lens 9 and enters the optical fiber 35.

[0015] The light source device 1 also includes a reflecting mirror 11, a first cylindrical lens 13, reflecting mirrors 15 and 17, a beam combining unit 19, a reflecting mirror 21, a half-wave plate 22, a polarizing beam splitter 23, and second and third cylindrical lenses 25 and 27 on the optical path from the first light source 3 to the dichroic mirror 33. The light source device 1 also includes reflecting mirrors 29 and 30, a half-wave plate 32, and a polarizing beam splitter 31 on the optical path from the second light source 5 and the third light source 7 to the dichroic mirror 33.

[0016] 1 and 2, the first light source 3 is composed of two first light sources 3a and 3b, which are arranged side by side. Both first light sources 3a and 3b emit light having the same polarization direction.

[0017] Furthermore, when describing matters common to the first light sources 3a and 3b, they will be described as the first light source 3.

[0018] [1-2. Light source unit configuration] The first light source 3 includes a plurality of first light source units 40 that emit red laser light. The first light source units 40 are arranged in a matrix in the X-axis direction and the Z-axis direction, for example, in 4 rows and 2 columns.

[0019] 3, the first light source 3a will be described, but the same applies to the first light source 3b. For ease of description, the two first light source units 40 farthest from the optical axis pa of the light incident on the condenser lens 9 will be referred to as the first light source units 40 in the first row rw1, and the first light source units 40 closer to the optical axis pa of the light incident on the condenser lens 9 will be referred to as the first light source units 40 in the second row rw2, the third row rw3, and the fourth row rw4, respectively. Furthermore, the four first light source units 40 farthest from the first cylindrical lens 13 will be referred to as the first light source units 40 in the first column c1, and the four first light source units 40 closer to the first cylindrical lens 13 will be referred to as the first light source units 40 in the second column c2.

[0020] Next, reference is made to Fig. 4. Fig. 4 is an explanatory diagram illustrating the collimation of light from the first light source 3. For ease of explanation, the reflecting mirror 11 disposed on the optical path between the first light source 3 and the first cylindrical lens 13 is omitted from Fig. 4.

[0021] The first light source unit 40 includes a first emitter 41 that emits a first emitter light Lg1, which is a red laser beam; a second emitter 43 that emits a second emitter light Lg2, which is also a red laser beam; and a collimator lens 45 through which the first emitter light Lg1 and the second emitter light Lg2 pass. The first and second emitters 41, 43 are each solid-state light-emitting elements and are arranged in a single light-emitting element 47. Therefore, the light-emitting element 47 is a multi-emitter light-emitting element. The first emitter light Lg1 and the second emitter light Lg2 are collectively referred to as light Lga. The collimator lens 45 is an example of a collimator lens unit.

[0022] The first and second emitter lights Lg1 and Lg2 emitted from the first and second emitters 41 and 43, respectively, are incident on the collimator lens 45. The collimator lens 45 suppresses the diffusion of the incident first and second emitter lights Lg1 and Lg2 and then emits them. Because one collimator lens 45 is shared by the two emitters, the first and second emitter lights Lg1 and Lg2 emitted from the collimator lens 45 cannot be completely collimated. Therefore, the first and second emitter lights Lg1 and Lg2 emitted from the collimator lens 45 are incident on the first cylindrical lens 13. The first cylindrical lens 13 collimates the incident first and second emitter lights Lg1 and Lg2, preventing the first and second emitter lights Lg1 and Lg2 from diverging.

[0023] Next, refer to Figure 5. Figure 5 is an enlarged side view of the periphery of the first light source unit 40. The reflecting mirrors 11 are arranged in one-to-one correspondence with the first light source units 40 so that their tilt can be adjusted. Therefore, even if the optical axes of the light beams Lga emitted from the multiple first light source units 40 in the first light source 3 are different from each other, the tilt of the light beams Lga can be corrected by adjusting the tilt of the reflecting mirror 11 so that the light beams Lga can be incident on the first cylindrical lens 13. This makes it possible to prevent the optical axes of the light beams Lga emitted from the first cylindrical lens 13 from tilting.

[0024] Furthermore, the reflecting mirrors 11 corresponding to the two first light source units 40 are arranged in a stepped manner, shifted in the Y-axis direction. This allows the interval E2 between the red light beams Lga reflected by the reflecting mirrors 11 to be shorter than the interval E1 between the red light beams Lga in each row before they are incident on each reflecting mirror 11, thereby increasing the density of the red laser light.

[0025] Each light beam Lga reflected by the reflecting mirror 11 travels along the optical axis pa of the condenser lens 9 and is collimated by the first cylindrical lens 13. Of the light beams Lga collimated by the first cylindrical lens 13, the light beam Lga from the first light source unit 40 arranged in the first row rw1, which is the farthest from the optical axis of the condenser lens 9, has its traveling direction bent by 90 degrees by the reflecting mirror 15 and travels in a direction perpendicular to the optical axis pa of the condenser lens 9.

[0026] The light Lga from the first light source unit 40 arranged in the second row rw2 is also collimated by the first cylindrical lens 13, and its direction of travel is bent by 90 degrees by the reflecting mirror 17 so that it travels in a direction perpendicular to the optical axis pa of the focusing lens 9.

[0027] The first and second emitter lights Lg1 and Lg2 from the first light source unit 40 arranged on the third row rw3 and the fourth row rw4 are collimated by the first cylindrical lens 13, and their direction of travel is bent 90 degrees by the beam combining section 19 so that they travel in a direction perpendicular to the optical axis of the light entering the focusing lens 9.

[0028] Next, the beam combining unit 19 will be described with reference to Figures 1, 2, and 6. Figure 6(a) is an explanatory diagram showing the configuration around the beam combining unit 19, Figure 6(b) is an explanatory diagram showing one surface (first surface 19a) of the beam combining unit 19, and Figure 6(c) is an explanatory diagram showing the other surface (second surface 19b).

[0029] The light beam combining unit 19 shortens the distance between the light beams in the X-axis direction of the light Lga traveling from each of the first light source units 40 in the first row rw1 to the fourth row rw4, thereby increasing the density of the light.

[0030] The light beam combining unit 19 has a first surface 19a and a second surface 19b facing each other. The light beams Lga emitted from the first light source units 40 in the third row rw3 and the fourth row rw4 are incident on the first surface 19a. The light beams Lga from the first light source unit 40 in the first row rw1 reflected by the reflecting mirror 15 and the first light source unit 40 in the second row rw2 reflected by the reflecting mirror 17 are incident on the second surface 19b.

[0031] The beam merging unit 19 has a base material 19c made of a colorless, transparent, light-transmitting member, and has reflective areas 19d that reflect light on both sides of the first surface 19a. The base material 19c is, for example, a glass or resin plate. The reflective areas 19d are, for example, formed by a reflective film on the base material 19c. The central area of the beam merging unit 19 is a transmissive area through which light passes, and is located between the two reflective areas 19d. The width D4 of each of the two reflective areas 19d is approximately 4 to 10 mm, and the width D3 of the transmissive area is approximately 8 to 12 mm. No reflective areas are arranged on the second surface 19b.

[0032] The reflecting mirrors 15 and 17 are arranged so that the reflected light Lga passes through a transmission region of the light beam combining section 19. The light beam combining section 19 is arranged so that the light Lga emitted from the first light source unit 40 in the third row rw3 is reflected by one reflection region 19d, and the light Lga emitted from the first light source unit 40 in the fourth row rw4 is reflected by the other reflection region 19d.

[0033] In this way, the distance D1 between the centers of the light beams of the light Lga emitted from the first light source units 40 in each row can be shortened to the distance D2 between the centers of the light beams of each light Lga after they are emitted from the beam combining section 19. Note that, although the first embodiment illustrates a case in which the three distances D2 shown in Fig. 6(a) are the same, the reflecting mirrors 15, 17 and the beam combining section 19 can also be configured so that the distances D2 are different from one another.

[0034] As shown in FIG. 2, the light beams Lga emitted from the first light source 3b are combined into a single densified beam by the beam combining unit 19, and then reflected by the reflecting mirror 21 in the Z-axis direction. A half-wave plate 22 is disposed between the reflecting mirror 21 and the polarizing beam splitter 23, and the light beams Lga reflected by the reflecting mirror 21 pass through the half-wave plate 22, rotating their polarization direction by 90 degrees. The light beams Lga that have passed through the half-wave plate 22 enter the polarizing beam splitter 23 as P-polarized light and pass through it. Meanwhile, the light beams Lga emitted from the first light source 3a are combined into a single densified beam by the beam combining unit 19, and then enter the polarizing beam splitter 23 as S-polarized light and are reflected in the Z-axis direction. Here, the polarizing beam splitter 23 transmits the P-polarized light Lga from the half-wave plate 22 in the Z-axis direction as is, and reflects the S-polarized light Lga emitted from the first light source 3a in the Z-axis direction. In this way, the light Lga emitted from the first light source 3a and the light Lga emitted from the first light source 3b can be merged.

[0035] Next, the second cylindrical lens 25 and the third cylindrical lens 27 will be described with reference to Fig. 7. The second cylindrical lens 25 and the third cylindrical lens 27 reduce the width of the red laser beam in the Y-axis direction. Because the width of the beams emitted by the first emitter 41 and the second emitter 43 that emit red laser beams is greater than the width of the beams emitted by the emitters that emit blue and green laser beams, these two cylindrical lenses reduce the width of the beams.

[0036] The width D6 in the Y-axis direction of the red laser light after exiting the third cylindrical lens 27 is smaller than the width D5 in the Y-axis direction of the red laser light traveling from the polarizing beam splitter 23 before entering the second cylindrical lens 25. This allows the width of the beam of red laser light to be matched to the widths of the beams of blue and green laser light, so that the white light combined by the dichroic mirror 33 can be focused into an optical fiber by a single focusing lens 9. The red laser light that has exited the third cylindrical lens 27 enters the dichroic mirror 33.

[0037] Next, the second light source 5 will be described with reference to Figures 1 and 2. The second light source 5 includes a plurality of second light source units 50 that emit green laser light. The second light source units 50 are arranged in a matrix in the X-axis direction and the Z-axis direction, for example, in 4 rows x 2 columns.

[0038] The second light source unit 50 includes one emitter that emits green laser light and a collimating lens that collimates the light emitted from the emitter. Therefore, the second light source unit 50 has a single-emitter light-emitting element. The light source device 1 includes three second light sources 5.

[0039] Two second light sources 5 are arranged side by side, and one second light source 5 and one third light source 7 are arranged side by side. Since the two second light sources 5 are arranged side by side, the second light source units 50 are arranged in a matrix of 4 rows and 4 columns.

[0040] Reflecting mirrors 29 are arranged in one-to-one correspondence with second light source units 50 so that their tilt can be adjusted. Therefore, even if the optical axes of the light beams of green laser light emitted from second light source units 50 are unevenly tilted due to individual differences between second light source units 50, by adjusting the tilt of reflecting mirrors 29 that reflect each green laser beam, the tilt of the optical axis of the green laser beam can be corrected and the green laser beam can be made to enter reflecting mirror 30. This makes it possible to prevent the optical axis of each green laser beam emitted from reflecting mirror 30 from tilting.

[0041] Furthermore, the reflecting mirrors 29 are arranged in each row so as to be shifted in the Y-axis direction relative to the four second light source units 50. This makes the intervals between the green laser beams reflected by the reflecting mirrors 29 shorter than the intervals between the green laser beams from each column before they are incident on each reflecting mirror 29, thereby making it possible to increase the density of the green laser beams.

[0042] Reflecting mirrors 30 are arranged corresponding to each row, and furthermore, each reflecting mirror 30 is arranged shifted in the traveling direction of the green laser light reflected by reflecting mirror 29. As a result, the interval between the green laser light reflected by reflecting mirror 30 is shorter than the interval between the green laser light from each row before it is incident on each reflecting mirror 30, so the green laser light can be further denser.

[0043] The four green laser beams are reflected by reflecting mirrors 30, which are positioned offset in the direction of travel of the green laser beam reflected by reflecting mirror 29, changing their direction of travel and densifying them. The densified green laser beams are incident on polarizing beam splitter 31 as P-polarized light. Polarizing beam splitter 31 is configured to reflect blue laser beams, and is also configured to reflect S-polarized light and transmit P-polarized light of the green laser beams. The 16 green laser beams pass through polarizing beam splitter 31 and are reflected by dichroic mirror 33.

[0044] Next, the third light source 7 will be described. The third light source 7 includes a plurality of third light source units 60 that emit blue laser light. The third light source units 60 are arranged in a matrix in the X-axis direction and the Z-axis direction, for example, in 4 rows and 2 columns.

[0045] The third light source unit 60 includes one emitter that emits blue laser light and a collimating lens that collimates the light emitted from the emitter. Therefore, the third light source unit 60 has a single-emitter light-emitting element. The light source device 1 includes one third light source 7.

[0046] Reflecting mirror 29 is also arranged in one-to-one correspondence with third light source unit 60 so that its tilt can be adjusted. Therefore, even if the optical axes of the light beams of blue laser light emitted from third light source unit 60 are unevenly tilted due to individual differences in third light source unit 60, by adjusting the tilt of reflecting mirror 29 that reflects each blue laser beam, the tilt of the optical axis of the blue laser beam can be corrected and made to enter reflecting mirror 29. This makes it possible to prevent the optical axes of each blue laser beam emitted from reflecting mirror 29 from tilting.

[0047] One second light source 5 and one third light source 7 are arranged side by side, so that the second light source units 50 and the third light source units 60 are arranged in a matrix of 4 rows and 4 columns.

[0048] Furthermore, the reflecting mirrors 29 are arranged in each row so as to be offset in the Y-axis direction from the two second light source units 50 and the two third light source units 60. This makes it possible to increase the density of the light beams, since the interval between the green and blue laser beams reflected by the reflecting mirrors 29 is shorter than the interval between the green and blue laser beams from each column before they are incident on each reflecting mirror 29.

[0049] Reflecting mirrors 30 are arranged corresponding to each row, and furthermore, each reflecting mirror 30 is arranged shifted in the traveling direction of the green and blue laser light reflected by reflecting mirror 29. As a result, the interval between the green and blue laser light reflected by reflecting mirror 30 is shorter than the interval between the green and blue laser light from each row before it is incident on each reflecting mirror 30, so the light flux can be made denser.

[0050] The green and blue laser beams, which are reflected by reflecting mirrors 29 and 30 to change direction and become more dense, travel toward polarizing beam splitter 31. Half-wave plate 32, located between reflecting mirror 30 and polarizing beam splitter 31, rotates the polarization direction of the passing green laser beam by 90 degrees. The eight P-polarized blue laser beams and the eight green laser beams, whose polarization direction has been rotated by half-wave plate 32 to become S-polarized beams, are reflected by polarizing beam splitter 31 and then further reflected by dichroic mirror 33. In this way, the green and blue laser beams that have exited polarizing beam splitter 31 and the red laser beam that have exited third cylindrical lens 27 are combined by dichroic mirror 33.

[0051] In the first embodiment, when the light source device 1 does not include the reflecting mirrors 15, 17, the beam combining unit 19, and the second and third cylindrical lenses 25, 27, i.e., when the red light is not densified, the width of the entire red light beam in the Y-axis direction is 20 mm, and the width of the red light beam in the X-axis direction is 38 mm. In this case, the coupling efficiency is 35%. Here, the coupling efficiency is the ratio of the amount of red light that is not eclipsed at the entrance of the optical fiber 35 and enters the fiber to the total amount of red light that reaches the optical fiber 35.

[0052] In contrast, when light source device 1 is equipped with reflecting mirrors 15, 17 and beam combining unit 19, the width of the red light beam in the Y-axis direction is 20 mm, and the width of the red light beam in the X-axis direction is reduced to 15 mm. In this case, the coupling efficiency is improved to 75%. Furthermore, when light source device 1 is equipped with second and third cylindrical lenses 25, 27, the width of the red light beam in the Y-axis direction is reduced to 12 mm, and the width of the red light beam in the X-axis direction is 15 mm. In this case, the coupling efficiency is improved to 85%.

[0053] [1-3. Effects, etc.] As described above, the light source device 1 includes the first light source 3, a plurality of first cylindrical lenses 13, a beam merging unit 19 arranged to narrow the width in the X-axis direction of the light beam emitted from the first light source 3 by transmitting a portion of the light from the plurality of first cylindrical lenses 13 and reflecting the remainder, and a condenser lens 9 that condenses the light emitted from the beam merging unit 19. The first light source 3 includes a first row of a plurality of light-emitting elements 47 arranged side by side in the X-axis direction and a plurality of collimating lenses 45 arranged corresponding to the first row of a plurality of light-emitting elements 47. The light-emitting elements 47 include a first emitter 41 that emits a first emitter light Lg1 and a second emitter 43 that emits a second emitter light Lg2, and the collimating lens 45 transmits the first emitter light Lg1 and the second emitter light Lg2. The plurality of first cylindrical lenses 13 are arranged corresponding to the plurality of light emitting elements 47 in the first row, respectively, and collimate the first emitter light Lg1 and the second emitter light Lg2 emitted from the first light source 3.

[0054] The beam combining unit 19 can narrow the width of the light beams emitted from the multiple first light-emitting elements 47 arranged in the X-axis direction, improving the coupling efficiency of light incident on the optical fiber 35 and providing a light source device 1 that can suppress damage to the optical fiber while transmitting high-power light. Furthermore, the diameter of the light beam incident on the optical fiber 35 can be reduced, eliminating the need for an optical fiber with a large diameter or a large numerical aperture. Reducing the diameter can significantly reduce the cost of the optical fiber itself, and reducing the numerical aperture can eliminate the need to use optical fiber made of materials with low durability, such as resin, thereby improving reliability.

[0055] The first light source 3 of the light source device 1 also has a second row of multiple light-emitting elements 47 arranged in the Z-axis direction, which intersects with the X-axis direction, relative to the first row of multiple light-emitting elements 47. The first emitter light Lg1 and the second emitter light Lg2 emitted from one light-emitting element 47 of the first row of multiple light-emitting elements 47 arranged in the Z-axis direction and one light-emitting element 47 of the second row of multiple light-emitting elements 47 arranged in the Z-axis direction are reflected by a reflecting mirror 11 and collimated by a single first cylindrical lens 13. While the first light source 3 has been described as having two light-emitting elements 47 arranged in the Z-axis direction, the number of light-emitting elements 47 arranged in the Z-axis direction may be three or more. In this case, by arranging a reflecting mirror 11 corresponding to each light-emitting element 47, the light from the multiple light-emitting elements 47 can be collimated by a single first cylindrical lens 13.

[0056] The spacing between each light beam emitted from multiple light-emitting elements 47 arranged in the Z-axis direction and transmitted through the collimator lens 45 can be narrowed by the reflecting mirror 11, thereby reducing the overall width of the multiple light beams.This improves the coupling efficiency of light entering the optical fiber 35, and provides a light source device 1 that can both suppress damage to the optical fiber and transmit high-output light.

[0057] The light source device 1 also includes a reflecting mirror 11 disposed on the optical path between each collimating lens 45 and the first cylindrical lens 13. This makes it possible to correct the inclination of the light Lga emitted from each light-emitting element 47 and transmitted through the collimating lens 45.

[0058] The first light source 3 also includes a light-emitting element 47 in which a first emitter 41 and a second emitter 43 are arranged. The first emitter 41 and the second emitter 43 are integrated into a single light-emitting element 47, which allows the size of the first light source 3 to be reduced, and at the same time, the width of the luminous flux can be reduced to emit high-power light.

[0059] A pair of cylindrical lenses (second and third cylindrical lenses 25, 27) is provided on the optical path between the beam combining unit 19 and the condenser lens 9. This makes it possible to narrow the width of the light beam in the Y-axis direction, which is different from the direction narrowed by the beam combining unit 19, thereby further improving the coupling efficiency of the light incident on the optical fiber 35 and further suppressing damage to the optical fiber 35.

[0060] The light source device 1 also includes a second light source 5 that emits green light, a third light source 7 that emits blue light, and an optical fiber 35 into which light condensed by a condenser lens 9 is incident. The first emitter light Lg1 and the second emitter light Lg2 are red light, and the light emitted from the first light source 3, the second light source 5, and the third light source 7 is incident on the condenser lens 9.

[0061] By densifying the red light of the first emitter light Lg1 and the second emitter light Lg2, the width of the light beam can be made to be approximately the same as that of the green light or blue light, so that the combined white light can be focused into an optical fiber using a single focusing lens 9.

[0062] (Embodiment 2) [2-1. Configuration of the light source device] FIG. 8 shows the configuration of a light source device 1A according to the second embodiment. As shown in FIG. 8, the light source device 1A includes a first light source 2, a second light source 4, a third light source 6, a first cylindrical lens 13, three reflecting mirrors 12, three beam combining units 71, a dichroic mirror 81, a dichroic mirror 82, and a condenser lens 9. The light source device 1A combines light emitted from the first light source 2 (e.g., red laser light), light emitted from the second light source 4 (e.g., green laser light), and light emitted from the third light source 6 (e.g., blue laser light), and condenses the combined light into an optical fiber 35. Note that the same components as those in the light source device 1 according to the first embodiment are designated by the same reference numerals, and redundant description will be omitted.

[0063] The light emitted from the first light source 2 passes through the first cylindrical lens 13, is partially reflected by the reflecting mirror 12, passes through the beam combining section 71, and the remaining light is reflected by the beam combining section 71. The light emitted from the second light source 4 and the light emitted from the third light source 6 are partially reflected by the reflecting mirror 12, are partially transmitted through the beam combining section 71, and the remaining light is reflected by the beam combining section 71. The distance between the optical axes of the light emitted from each of the light-emitting elements of the first to third light sources 2, 4, and 6 is reduced by the beam combining section 71, as shown in FIG. 8, and the width of the beam of each of the light emitted from the first to third light sources 2, 4, and 6 is reduced.

[0064] Light emitted from the first light source 2 passes through two dichroic mirrors 81 and 82 and reaches the condenser lens 9. Light emitted from the second light source 4 is reflected by the dichroic mirror 81, passes through the dichroic mirror 82 and reaches the condenser lens 9. Light emitted from the third light source 6 is reflected by the dichroic mirror 82 and reaches the condenser lens 9. In this way, the red light emitted from the first light source 2 and the green light emitted from the second light source 4 are combined by the dichroic mirror 81, and this combined light and the blue light emitted from the third light source 6 are combined by the dichroic mirror 82, are collected by the condenser lens 9, and enter the optical fiber 35.

[0065] Dichroic mirror 81 has the property of transmitting red light and reflecting green light, while dichroic mirror 82 has the property of transmitting red and green light and reflecting blue light.

[0066] FIG. 9 is a perspective view showing the appearance of the first light source. The first to third light sources 2, 4, and 6 have the same appearance. In the first to third light sources 2, 4, and 6, a plurality of light-emitting elements each having an emitter that emits light are arranged in an array (4 columns x 6 rows), and the distance between the light-emitting elements is short. Therefore, a collimating lens portion 46a for collimating the emitted light is joined to the collimating lens portion 46a of an adjacent light-emitting element 47 to form a collimating lens array 46. That is, the first to third light sources 2, 4, and 6 differ from the first to third light sources 3, 5, and 7 of the first embodiment, which have a plurality of collimating lenses corresponding to each of the plurality of light-emitting elements, in that they have a single collimating lens array corresponding to all of the plurality of light-emitting elements.

[0067] FIG. 10 is an explanatory diagram illustrating the collimation of light from the first light source. To achieve high output, the first light source 2 has each light-emitting element 47 with two emitters (first and second emitters 41 and 43), similar to the first light source 3 of the first embodiment. The first emitter light Lg1 and the second emitter light Lg2 emitted from the first and second emitters 41 and 43, respectively, and transmitted through the collimator lens array are not parallel. The first emitter light Lg1 and the second emitter light Lg2 are substantially parallelized by passing through a first cylindrical lens 13 positioned at a position where the first emitter light Lg1 and the second emitter light Lg2 are separated. The second light source 4 and the third light source 6 may also be light-emitting elements with multiple emitters. In this case, a first cylindrical lens 13 may also be disposed for the second light source 4 and the third light source 6.

[0068] FIG. 11 shows the configuration of the beam merging unit 71. The beam merging unit 71 includes reflective regions 71b partially formed on the surface of a light-transmitting substrate 71a. The substrate 71a is, for example, a glass or resin plate. In the light source device 1A, three rectangular reflective regions 71b elongated in the row direction are arranged to correspond to the arrangement of the light-emitting elements. The width D6 of each of the three reflective regions 71b is approximately 3 to 5 mm, and the width D5 of the light-transmitting region (transmission region) between the reflective regions 71b is approximately 3 to 5 mm. A portion of the light emitted from each of the first to third light sources 2, 4, and 6 (light from the light-emitting elements arranged in the three rows) is reflected by the reflective regions 71b, while the remaining light (light from the light-emitting elements arranged in the other three rows) is reflected by the reflecting mirror 12 and then passes through the beam merging unit 71 (the region of the substrate 71a where the reflective regions 71b are not formed). In this way, the beam merging unit 71 can merge incident light from two directions.

[0069] The arrangement of the first to third light sources 2, 4, and 6 may be different from the example shown in FIG. 8 . In that case, similar light combination can be achieved by using dichroic mirrors with different characteristics instead of the dichroic mirrors 81 and 82, or by changing the arrangement of the mirrors. For example, in the light source device 1A, the first light source 2 is arranged so that the column direction of the array of the light-emitting elements 47 is the Z-axis direction. However, as with the second and third light sources 4 and 6, the column direction of the array of the light-emitting elements 47 can also be the X-axis direction. Furthermore, the first light source 2 can also be arranged so that the column direction of the array of the light-emitting elements 47 is the X-axis direction and the row direction is the Z-axis direction, or the column direction is the Z-axis direction and the row direction is the X-axis direction. In this case, the emission direction of light from the first light source 2 (the Y-axis direction) can be changed to the Z-axis direction or the X-axis direction using the reflecting mirror 11, as described in the first embodiment.

[0070] [2-2. Effects, etc.] As described above, the light source device 1A includes the first light source 2, the plurality of first cylindrical lenses 13, the beam merging unit 71 arranged to narrow the width in the Z-axis direction of the light beam emitted from the first light source 2 by transmitting a portion of the light from the plurality of first cylindrical lenses 13 and reflecting the remainder, and the condenser lens 9 that condenses the light emitted from the beam merging unit 71. The first light source 2 includes a first row of light-emitting elements 47 arranged in the Z-axis direction and a collimator lens array 46 formed with a plurality of collimator lens portions 46a arranged corresponding to the first row of light-emitting elements 47. The light-emitting elements 47 include a first emitter 41 that emits a first emitter light Lg1 and a second emitter 43 that emits a second emitter light Lg2, and the collimator lens portion 46a transmits the first emitter light Lg1 and the second emitter light Lg2. The plurality of first cylindrical lenses 13 are arranged corresponding to the plurality of light emitting elements 47 in the first row, respectively, and collimate the first emitter light Lg1 and the second emitter light Lg2 emitted from the first light source 2.

[0071] The beam combining unit 71 can narrow the width of the light beams emitted from the first row of light-emitting elements 47 aligned in the Z-axis direction, improving the coupling efficiency of light incident on the optical fiber 35 and providing a light source device 1A that can simultaneously suppress damage to the optical fiber and transmit high-power light. Furthermore, the diameter of the light beam incident on the optical fiber 35 can be reduced, eliminating the need for an optical fiber with a large diameter or a large numerical aperture. Reducing the diameter can significantly reduce the cost of the optical fiber itself, and reducing the numerical aperture can eliminate the need to use optical fiber made of materials with low durability, such as resin, thereby improving reliability.

[0072] The first light source 2 of the light source device 1A also has a second row of multiple light-emitting elements 47 arranged in the Y-axis direction intersecting the Z-axis direction with the first row of multiple light-emitting elements 47. The first emitter light Lg1 and the second emitter light Lg2 emitted from one light-emitting element 47 of the first row of multiple light-emitting elements 47 arranged in the Y-axis direction and one light-emitting element 47 of the second row of multiple light-emitting elements 47 are collimated by one first cylindrical lens 13.

[0073] The light from each of the plurality of light emitting elements 47 aligned in the Y-axis direction can be collimated by one first cylindrical lens 13, which contributes to reducing the number of parts and making the light source device more compact.

[0074] The light source device 1A also includes a second light source 4 that emits green light, a third light source 6 that emits blue light, and an optical fiber 35 into which light condensed by a condenser lens 9 is incident. The first emitter light Lg1 and the second emitter light Lg2 are red light, and the light emitted from the first light source 2, the second light source 4, and the third light source 6 is incident on the condenser lens 9.

[0075] By collimating the red light of the first emitter light Lg1 and the second emitter light Lg2, it is possible to focus the white light combined with the green light and blue light into an optical fiber using a single focusing lens.

[0076] (Embodiment 3) [3-1. Configuration of the light source device] FIG. 12 shows the configuration of a light source device 1B according to the third embodiment. As shown in FIG. 12, the light source device 1B includes a first light source 2, a second light source 4, a third light source 6, a first cylindrical lens 13, three reflecting mirrors 16, three reflecting mirrors 18, three half-wave plates 22a, 22b, and 22c, three polarizing beam splitters 31a, 31b, and 31c, a dichroic mirror 81, a dichroic mirror 82, and a condenser lens 9. The light source device 1B combines light emitted from the first light source 2 (e.g., red laser light), light emitted from the second light source 4 (e.g., green laser light), and light emitted from the third light source 6 (e.g., blue laser light), and condenses the combined light into an optical fiber 35. Note that the same components as those in the light source device 1A according to the second embodiment are designated by the same reference numerals, and redundant description will be omitted.

[0077] The light emitted from the first light source 2 passes through the first cylindrical lens 13, becomes approximately parallel, and is reflected by the reflecting mirror 16. A portion of the light reflected by the reflecting mirror 16 is reflected by the reflecting mirror 18, and enters the polarizing beam splitter 31a as S-polarized light, where it is reflected. The remainder of the light reflected by the reflecting mirror 16 enters the half-wave plate 22a, where its polarization direction is rotated by 90°, and enters the polarizing beam splitter 31a as P-polarized light, where it is transmitted. The polarizing beam splitter 31a acts as a beam combining section, and by superimposing multiple light beams, the width of the light beam can be reduced.

[0078] The light emitted from the second light source 4 is reflected by the reflecting mirror 16. A portion of the light reflected by the reflecting mirror 16 is incident on the half-wave plate 22b, where the polarization direction is rotated by 90°, and is reflected by the reflecting mirror 18. The light then enters the polarizing beam splitter 31b as S-polarized light and is reflected therefrom. The remainder of the light reflected by the reflecting mirror 16 enters the polarizing beam splitter 31b as P-polarized light and is transmitted through it. The polarizing beam splitter 31b acts as a beam combining section, and by superimposing multiple beams of light, the width of the light beam can be reduced.

[0079] The light emitted from the third light source 6 is reflected by the reflecting mirror 16. A portion of the light reflected by the reflecting mirror 16 is incident on the half-wave plate 22c, where the polarization direction is rotated by 90°, and is reflected by the reflecting mirror 18. The light then enters the polarizing beam splitter 31c as S-polarized light and is reflected there. The remainder of the light reflected by the reflecting mirror 16 enters the polarizing beam splitter 31c as P-polarized light and is transmitted through it. The polarizing beam splitter 31c acts as a beam combining section, and by superimposing multiple beams of light, the width of the light beam can be reduced.

[0080] The light emitted from the first light source 2 and superimposed by the polarizing beam splitter 31a passes through dichroic mirrors 81 and 82 and reaches the condenser lens 9. The light emitted from the second light source 4 and superimposed by the polarizing beam splitter 31b is reflected by the dichroic mirror 81, passes through the dichroic mirror 82 and reaches the condenser lens 9. The light emitted from the third light source 6 and superimposed by the polarizing beam splitter 31c is reflected by the dichroic mirror 82 and reaches the condenser lens 9. In this way, the red light emitted from the first light source 2 and the green light emitted from the second light source 4 are combined by the dichroic mirror 81, and the combined light and the blue light emitted from the third light source 6 are combined by the dichroic mirror 82, collected by the condenser lens 9, and enter the optical fiber 35.

[0081] In the case of light source device 1B, the arrangement order of the first to third light sources 2, 4, and 6 may also be different from that shown in FIG. 12 . In this case, similar light combination can be achieved by using dichroic mirrors with different characteristics instead of dichroic mirrors 81 and 82, or by changing the arrangement of the mirrors. For example, in light source device 1B, first light source 2 is arranged so that the column direction of the array of light-emitting elements 47 is aligned with the Z-axis direction. However, as with the second and third light sources 4 and 6, the column direction of the array of light-emitting elements 47 may also be aligned with the X-axis direction. Furthermore, first light source 2 may also be arranged so that the column direction of the array of light-emitting elements 47 is aligned with the X-axis direction and the row direction is aligned with the Z-axis direction, or the column direction is aligned with the Z-axis direction and the row direction is aligned with the X-axis direction. In this case, the emission direction (Y-axis direction) of light from first light source 2 can be changed to the Z-axis direction or the X-axis direction using reflecting mirror 11, as described in the first embodiment.

[0082] [3-2. Effects, etc.] As described above, light source device 1B includes first light source 2, a plurality of first cylindrical lenses 13, polarizing beam splitter 31a as a light beam combining unit arranged to narrow the width in the Z-axis direction of the light flux emitted from first light source 2 by transmitting a portion of the light from the plurality of first cylindrical lenses 13 and reflecting the remainder, and condenser lens 9 that condenses the light emitted from polarizing beam splitter 31a. First light source 2 includes a first row of light-emitting elements 47 arranged side by side in the Z-axis direction, and collimator lens array 46 formed with a plurality of collimator lens portions 46a arranged corresponding to the first row of light-emitting elements 47. The light-emitting element 47 has a first emitter 41 that emits a first emitter light Lg1 and a second emitter 43 that emits a second emitter light Lg2, and the collimator lens portion 46a transmits the first emitter light Lg1 and the second emitter light Lg2. The multiple first cylindrical lenses 13 are arranged corresponding to the multiple light-emitting elements 47 in the first row, respectively, and collimate the first emitter light Lg1 and the second emitter light Lg2 emitted from the first light source 2.

[0083] The width of the light beam emitted from the first row of light-emitting elements 47 aligned in the Z-axis direction can be narrowed by the polarizing beam splitter 31a, improving the coupling efficiency of light incident on the optical fiber 35 and providing a light source device 1B that achieves both suppression of damage to the optical fiber and transmission of high-power light. Furthermore, the diameter of the light beam incident on the optical fiber 35 can be reduced, eliminating the need for an optical fiber with a large diameter or a large numerical aperture. Reducing the diameter can significantly reduce the cost of the optical fiber itself, and reducing the numerical aperture can eliminate the need to use optical fiber made of materials with low durability, such as resin, thereby improving reliability.

[0084] Furthermore, the first light source 2 of the light source device 1B has a second row of multiple light-emitting elements 47 arranged in the Y-axis direction intersecting the Z-axis direction with respect to the first row of multiple light-emitting elements 47. The first emitter light Lg1 and the second emitter light Lg2 emitted from one light-emitting element 47 of the first row of multiple light-emitting elements 47 arranged in the Y-axis direction and one light-emitting element 47 of the second row of multiple light-emitting elements 47 are collimated by one first cylindrical lens 13.

[0085] The light from each of the plurality of light emitting elements 47 aligned in the Y-axis direction can be collimated by one first cylindrical lens 13, which contributes to reducing the number of parts and making the light source device more compact.

[0086] The light source device 1B also includes a second light source 4 that emits green light, a third light source 6 that emits blue light, and an optical fiber 35 into which light condensed by a condenser lens 9 is incident. The first emitter light Lg1 and the second emitter light Lg2 are red light, and the light emitted from the first light source 2, the second light source 4, and the third light source 6 is incident on the condenser lens 9.

[0087] By collimating the red light of the first emitter light Lg1 and the second emitter light Lg2, it is possible to focus the white light combined with the green light and blue light into an optical fiber using a single focusing lens.

[0088] As described above, the embodiments have been described as examples of the technology of the present disclosure. For this purpose, the accompanying drawings and detailed description have been provided. Therefore, the components described in the accompanying drawings and detailed description may include not only components essential for solving the problem, but also components that are not essential for solving the problem in order to exemplify the above technology. Therefore, the fact that these non-essential components are described in the accompanying drawings or detailed description should not be interpreted as immediately indicating that these non-essential components are essential.

[0089] Furthermore, since the above-described embodiments are intended to illustrate the technology of the present disclosure, various modifications, substitutions, additions, omissions, etc. may be made within the scope of the claims or their equivalents.

[0090] (Outline of the embodiment) (1) A light source device according to the present disclosure includes a first light source, a plurality of first cylindrical lenses, a beam merging unit arranged to narrow the width of a light beam emitted from the first light source in a first direction by transmitting a portion of the light from the plurality of first cylindrical lenses and reflecting the remainder, and a condensing lens that condenses the light emitted from the beam merging unit. The first light source includes a first row of light-emitting elements arranged in the first direction and a plurality of collimating lens units arranged corresponding to the first row of light-emitting elements, each of which has a first emitter that emits first light and a second emitter that emits second light, and each of the plurality of collimating lens units transmits the first light and the second light. The plurality of first cylindrical lenses are arranged corresponding to the first row of light-emitting elements, each of which collimates the first light and the second light emitted from the first light source.

[0091] This means that by placing the end of the optical fiber at the focal position of the focusing lens, it is possible to improve the coupling efficiency of light entering the optical fiber, providing a light source device that can both suppress damage to the optical fiber and transmit high-power light.

[0092] (2) In the light source device of (1), the plurality of light emitting elements in the first row are arranged in an array.

[0093] (3) In the light source device of (1), the first light source has a second row of multiple light-emitting elements arranged in a second direction intersecting the first direction with respect to the first row of multiple light-emitting elements, and each of the second row of multiple light-emitting elements has a first emitter and a second emitter. The first light and the second light from one light-emitting element of the first row of multiple light-emitting elements arranged in the second direction and one light-emitting element of the second row of multiple light-emitting elements are collimated by one first cylindrical lens of the multiple first cylindrical lenses.

[0094] (4) The light source device of (3) further includes a reflecting mirror arranged on the optical path between one of the plurality of light-emitting elements in the first row and one of the plurality of light-emitting elements in the second row and the first cylindrical lens.

[0095] (5) The light source device of (1) includes a pair of cylindrical lenses on the optical path between the beam merging unit and the condenser lens.

[0096] (6) The light source device according to any one of (1) to (5) includes a second light source that emits green light, a third light source that emits blue light, and an optical fiber into which light condensed by a condenser lens is incident. The first light and the second light are red light, and the light emitted from the first light source, the second light source, and the third light source is incident on the condenser lens. [Industrial Applicability]

[0097] The present disclosure is applicable to a light source device that emits light from an emitter. [Explanation of symbols]

[0098] 1, 1A, 1B light source device 2, 3, 3a, 3b First light source 4, 5 Second light source 6, 7 Third Light Source 9 Condenser Lens 9a Focus position 11, 12, 15, 16, 17, 18, 21, 29, 30 Reflective mirrors 13 First cylindrical lens 19, 71 Ray merging section 19a First Side 19b Second Side 19c, 71a base material 19d, 71b reflective area 22, 22a, 22b, 22c, 32 1 / 2 wave plate 23, 31, 31a, 31b, 31c Polarizing beam splitter 25 Second cylindrical lens 27 Third Cylindrical Lens 33, 81, 82 Dichroic mirror 35 Optical Fiber 35a End of optical fiber 40 First light source unit 41 First Emitter 43 Second Emitter 45 Collimating Lens 46 Collimating Lens Array 46a Collimating lens part 47 Light-emitting element 50 Second light source unit 60 Third light source unit Lg1 First emitter light Lg2 Second emitter light Lga Optical

Claims

1. a first light source having a first row of a plurality of light-emitting elements arranged in a first direction and a plurality of collimating lens portions arranged corresponding to the plurality of light-emitting elements in the first row, each of the plurality of light-emitting elements in the first row having a first emitter that emits a first light and a second emitter that emits a second light, and each of the plurality of collimating lens portions that transmit the first light and the second light; a plurality of first cylindrical lenses that are arranged corresponding to the plurality of light-emitting elements in the first row, respectively, and that collimate the first light and the second light emitted from the first light source; a beam combining unit that is arranged to transmit a portion of the light from the plurality of first cylindrical lenses and reflect the remainder, thereby narrowing the width of the light beam emitted from the first light source in the first direction; a condenser lens that condenses the light emitted from the light beam merging unit, Light source device.

2. the first light source includes a second row of a plurality of light-emitting elements arranged side by side in a second direction intersecting the first direction with respect to the first row of a plurality of light-emitting elements, and each of the second row of a plurality of light-emitting elements includes the first emitter and the second emitter; the first light and the second light from one light-emitting element among the plurality of light-emitting elements in the first row arranged in the second direction and one light-emitting element among the plurality of light-emitting elements in the second row are collimated by one first cylindrical lens among the plurality of first cylindrical lenses; The light source device according to claim 1 .

3. a reflecting mirror disposed on an optical path between one light-emitting element of the plurality of light-emitting elements in the first row and one light-emitting element of the plurality of light-emitting elements in the second row and the one first cylindrical lens, The light source device according to claim 2 .

4. A set of cylindrical lenses is provided on an optical path between the beam combining unit and the condenser lens. The light source device according to claim 1 .

5. a second light source that emits green light; a third light source that emits blue light; an optical fiber into which the light condensed by the condensing lens is incident, the first light and the second light are red light, The light beams emitted from the first light source, the second light source, and the third light source are incident on the condenser lens and the optical fiber. The light source device according to claim 1 .

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