Light-emitting devices and vehicles

Abstract

To provide a light-emitting device that can illuminate a diffusion fiber more uniformly. [Solution] The light-emitting device comprises a light source that emits laser light, a first optical member that splits the laser light into a first branched laser beam and a second branched laser beam, reflects the first branched laser beam, and transmits the second branched laser beam, and a first diffusion fiber having a first end into which at least a portion of the first branched laser beam reflected by the first optical member is incident, and a second end into which at least a portion of the second branched laser beam is incident.

Description

Technical Field

[0001] Embodiments relate to a light-emitting device and a vehicle.

Background Art

[0002] In a light-emitting device used in a vehicle or the like, there is a structure in which laser light emitted from a light source is made to enter a diffusion fiber, causing the entire diffusion fiber to emit light. However, with such a structure, one end side of the diffusion fiber into which the laser light is made to enter may become brighter than the other end side. In a light-emitting device, it is required to make the diffusion fiber emit light more uniformly.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An embodiment aims to provide a light-emitting device and a vehicle capable of making a diffusion fiber emit light more uniformly.

Means for Solving the Problems

[0005] A light-emitting device according to an embodiment of the present invention includes a light source that irradiates laser light, a first optical member that branches the laser light into first branched laser light and second branched laser light, reflects the first branched laser light, and transmits the second branched laser light, a first end portion into which at least a part of the first branched laser light reflected by the first optical member enters, and a first diffusion fiber having a second end portion into which at least a part of the second branched laser light enters.

Effects of the Invention

[0006] According to one embodiment of the present invention, a light-emitting device and a vehicle can be realized that can illuminate a diffusion fiber more uniformly. [Brief explanation of the drawing]

[0007] [Figure 1] This is a perspective view showing a light-emitting device according to the first embodiment. [Figure 2] This is an explanatory diagram showing a light-emitting device according to the first embodiment. [Figure 3] This is an explanatory diagram showing a light-emitting device according to a first modified example of the first embodiment. [Figure 4] This is an explanatory diagram showing a light-emitting device according to a second modified example of the first embodiment. [Figure 5] This is an explanatory diagram showing a light-emitting device according to a third modified example of the first embodiment. [Figure 6] This is an explanatory diagram showing a light-emitting device according to a fourth modified example of the first embodiment. [Figure 7] This is an explanatory diagram showing a light-emitting device according to a fifth modified example of the first embodiment. [Figure 8] This is an explanatory diagram showing a light-emitting device according to a sixth modified example of the first embodiment. [Figure 9] This is an explanatory diagram showing a light-emitting device according to a seventh modified example of the first embodiment. [Figure 10] This is an explanatory diagram showing a light-emitting device according to the second embodiment. [Figure 11] This is an explanatory diagram showing a light-emitting device according to the third embodiment. [Figure 12] This is an explanatory diagram showing a light-emitting device according to the fourth embodiment. [Figure 13] This is an explanatory diagram showing a light-emitting device according to the fifth embodiment. [Figure 14] This is an explanatory diagram showing a light-emitting device according to the sixth embodiment. [Figure 15] This is an explanatory diagram showing a light-emitting device according to the first modified example of the sixth embodiment. [Figure 16] This is an explanatory diagram showing a light-emitting device according to a second modified example of the sixth embodiment. [Figure 17]It is a perspective view showing a vehicle equipped with a light-emitting device according to an embodiment. [Figure 18] It is an explanatory view showing a tail lamp equipped with a light-emitting device according to an embodiment.

Mode for Carrying Out the Invention

[0008] Hereinafter, each embodiment of the present invention will be described with reference to the drawings. The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the ratio of the sizes between parts, etc. are not necessarily the same as the actual ones. Even when representing the same part, the dimensions and ratios may be represented differently in the drawings. In this specification and each figure, the same elements as those already described are denoted by the same reference numerals, and detailed descriptions are appropriately omitted.

[0009] <Light-emitting device> (First Embodiment) FIG. 1 is a perspective view showing a light-emitting device according to the first embodiment. FIG. 2 is an explanatory view showing a light-emitting device according to the first embodiment. As shown in FIGS. 1 and 2, the light-emitting device 100 according to the first embodiment includes a light source 10, a first optical member 21, and a first diffusion fiber 31.

[0010] (Light source) The light source 10 irradiates laser light LT. In the light-emitting device 100, the light source 10 includes a first light source unit 11a, a second light source unit 11b, a third light source unit 11c, a first collimating lens 12a, a second collimating lens 12b, a third collimating lens 12c, a first dichroic mirror 13a, and a second dichroic mirror 13b.

[0011] The first light source unit 11a emits a first laser beam LT1. The first laser beam LT1 has a first peak wavelength. The first laser beam LT1 is, for example, blue laser light. The first peak wavelength is, for example, 400 nm or more and less than 500 nm. The first light source unit 11a is, for example, a laser diode. The first laser beam LT1 may be green laser light or red laser light.

[0012] The second light source unit 11b emits a second laser beam LT2. The second laser beam LT2 has a second peak wavelength. The second peak wavelength is different from the first peak wavelength. For example, the difference between the second peak wavelength and the first peak wavelength is 10 nm or more. The second laser beam LT2 is, for example, green laser light. The second peak wavelength is, for example, 500 nm or more and less than 600 nm. The second light source unit 11b is, for example, a laser diode. The second laser beam LT2 may be blue laser light or red laser light.

[0013] The third light source unit 11c emits a third laser beam LT3. The third laser beam LT3 has a third peak wavelength. The third peak wavelength is different from the first and second peak wavelengths. For example, the difference between the third peak wavelength and the second and first peak wavelengths is 10 nm or more. The third laser beam LT3 is, for example, red laser light. The third peak wavelength is, for example, 600 nm or more and 700 nm or less. The third light source unit 11c is, for example, a laser diode. The third laser beam LT3 may also be blue laser light or green laser light.

[0014] The first collimating lens 12a collimates the first laser beam LT1. The second collimating lens 12b collimates the second laser beam LT2. The third collimating lens 12c collimates the third laser beam LT3. Here, collimation means that the light rays become parallel. Note that parallelism includes an error of ±3°.

[0015] The first dichroic mirror 13a transmits the first laser beam LT1 and reflects the second laser beam LT2. The second dichroic mirror 13b transmits both the first laser beam LT1 and the second laser beam LT2 and reflects the third laser beam LT3.

[0016] (First optical component) The first optical element 21 splits the laser beam LT into a first branched laser beam LTB1 and a second branched laser beam LTB2. The first optical element 21 reflects the first branched laser beam LTB1 and transmits the second branched laser beam LTB2. The first optical element 21 is, for example, a beam splitter.

[0017] (First diffusion fiber) The first diffusion fiber 31 has a first end 31a, a second end 31b, and a first intermediate portion 31c. The first end 31a is located at one end of the first diffusion fiber 31. The second end 31b is located at the other end of the first diffusion fiber 31. The first intermediate portion 31c is located between the first end 31a and the second end 31b. At least a portion of the first branched laser beam LTB1 reflected by the first optical member 21 is incident on the first end 31a. At least a portion of the second branched laser beam LTB2 is incident on the second end 31b.

[0018] The first end portion 31a has a first incident surface 31a1 into which the first branched laser beam LTB1 is incident. The second end portion 31b has a second incident surface 31b1 into which the second branched laser beam LTB2 is incident. In the light-emitting device 100, the first incident surface 31a1 and the second incident surface 31b1 are arranged to face the same direction. The distance D1 between the center of the first incident surface 31a1 and the center of the second incident surface 31b1 is, for example, between 1 mm and 100 mm.

[0019] Furthermore, the light-emitting device 100 further comprises a second optical element 22, a first condensing lens 41, a second condensing lens 42, and a housing 80. The second optical element 22, the first condensing lens 41, the second condensing lens 42, and the housing 80 are optional.

[0020] (Second optical component) The second optical element 22 reflects at least a portion of the second branched laser beam LTB2. In the light-emitting device 100, the second optical element 22 is a mirror that reflects all of the second branched laser beam LTB2.

[0021] (First and second focusing lenses) The first focusing lens 41 focuses the first branched laser beam LTB1 and directs it into the first end 31a of the first diffusion fiber 31. The second focusing lens 42 focuses the second branched laser beam LTB2 and directs it into the second end 31b of the first diffusion fiber 31.

[0022] (Enclosure) The light source 10, the first optical element 21, the second optical element 22, the first condensing lens 41, and the second condensing lens 42 are arranged inside the housing 80. The housing 80 holds the light source 10, the first optical element 21, the second optical element 22, the first condensing lens 41, and the second condensing lens 42. The first diffusion fiber 31 is arranged outside the housing 80. The first end 31a and the second end 31b of the first diffusion fiber 31 are connected to the housing 80.

[0023] In the light-emitting device 100, the first laser beam LT1 emitted from the first light source unit 11a is collimated by the first collimating lens 12a and passes through the first dichroic mirror 13a. The second laser beam LT2 emitted from the second light source unit 11b is collimated by the second collimating lens 12b and reflected by the first dichroic mirror 13a. The collimated first laser beam LT1 and the collimated second laser beam LT2 are wavelength-combined by the first dichroic mirror 13a. The laser light obtained by combining the first laser beam LT1 and the second laser beam LT2 passes through the second dichroic mirror 13b. The third laser beam LT3 emitted from the third light source unit 11c is collimated by the third collimating lens 12c and reflected by the second dichroic mirror 13b. The laser beam obtained by combining the first laser beam LT1 and the second laser beam LT2, and the collimated third laser beam LT3, are wavelength-combined by the second dichroic mirror 13b. As a result, the light source 10 irradiates with laser beam LT, which is obtained by combining the first laser beam LT1, the second laser beam LT2, and the third laser beam LT3. For example, if the first laser beam LT1 is blue laser light, the second laser beam LT2 is green laser light, and the third laser beam LT3 is red laser light, the light source 10 irradiates with laser beam LT, which is obtained by wavelength-combining red laser light, green laser light, and blue laser light.

[0024] The laser beam LT emitted from the light source 10 is split into a first branched laser beam LTB1 and a second branched laser beam LTB2 in the first optical member 21. The first branched laser beam LTB1 is focused by the first focusing lens 41 and incident on the first end 31a of the first diffusion fiber 31. The first branched laser beam LTB1 incident from the first end 31a passes through the first intermediate section 31c and heads toward the second end 31b. A portion of the first branched laser beam LTB1 incident from the first end 31a is emitted, for example, from the second end 31b. The second branched laser beam LTB2 is reflected by the second optical member 22, focused by the second focusing lens 42, and incident on the second end 31b of the first diffusion fiber 31. The second branched laser beam LTB2 incident from the second end 31b passes through the first intermediate section 31c and heads toward the first end 31a. A portion of the second branched laser beam LTB2, which is incident from the second end 31b, is emitted from, for example, the first end 31a.

[0025] In this way, the light-emitting device 100 splits the laser beam LT emitted from the light source 10 into a first branched laser beam LTB1 and a second branched laser beam LTB2, and directs them to the first end 31a and the second end 31b of the first diffuse fiber 31, respectively. This allows the first diffuse fiber 31 to be illuminated more uniformly compared to the case where the laser beam is directed from only one end of the first diffuse fiber 31. Furthermore, the light-emitting device 100 can be made smaller compared to the case where the laser beam LT is not split into a first branched laser beam LTB1 and a second branched laser beam LTB2, and light sources are provided at both ends of the first diffuse fiber 31.

[0026] Furthermore, in the light-emitting device 100, the output of the laser beam LT can be increased by irradiating the light source 10 with laser light obtained by combining the first laser beam LT1 emitted from the first light source unit 11a and the second laser beam LT2 emitted from the second light source unit 11b.

[0027] Furthermore, in the light-emitting device 100, the first laser beam LT1 has a first peak wavelength, and the second laser beam LT2 has a second peak wavelength different from the first peak wavelength, allowing laser beams LT of various colors to be incident on the first diffusion fiber 31.

[0028] Furthermore, in the light-emitting device 100, the light source 10 irradiates the first diffusion fiber 31 with white laser light LT, which is obtained by wavelength-combining red laser light, green laser light, and blue laser light. It is preferable to make the radiant flux of the red laser light greater than that of the green laser light, and the radiant flux of the green laser light greater than that of the blue laser light. For example, by making the first laser light LT1 emitted from the first light source unit 11a a blue laser light, the second laser light LT2 emitted from the second light source unit 11b a green laser light, and the third laser light LT3 emitted from the third light source unit 11c a red laser light, the optical path length of the red laser light can be made shorter than that of the green laser light, and the optical path length of the green laser light can be made shorter than that of the blue laser light. As a result, the radiant flux of the red laser light can be made greater than that of the green laser light, and the radiant flux of the green laser light can be made greater than that of the blue laser light.

[0029] Furthermore, in the light-emitting device 100, the first incident surface 31a1 and the second incident surface 31b1 are arranged to face the same direction, which reduces the need to route or bend the first diffusion fiber 31 when arranging it. This improves the design flexibility when the light-emitting device 100 is lit.

[0030] Furthermore, in the light-emitting device 100, the distance D1 between the center of the first incident surface 31a1 and the center of the second incident surface 31b1 is between 1 mm and 100 mm, which reduces the difference between the distance from the light source 10 to the first focusing lens 41 and the distance from the light source 10 to each incident surface of the second focusing lens 42. As a result, the effect of laser beam spreading can be reduced, and the focusing efficiency of the first focusing lens 41 and the second focusing lens 42 can be made equivalent. In addition, the light-emitting device 100 can be miniaturized.

[0031] (First embodiment, first modified example) Figure 3 is an explanatory diagram showing a light-emitting device according to a first modified example of the first embodiment. As shown in Figure 3, the light-emitting device 100A according to the first modified example of the first embodiment is substantially the same as the light-emitting device 100, except that the light source 10 is different.

[0032] In the light-emitting device 100A, the light source 10 includes a first light source section 11a, a second light source section 11b, a first collimating lens 12a, a second collimating lens 12b, and a first dichroic mirror 13a. In the light-emitting device 100A, the light source 10 does not include a third light source section 11c, a third collimating lens 12c, or a second dichroic mirror 13b.

[0033] In the light-emitting device 100A, the first laser beam LT1 emitted from the first light source unit 11a is collimated by the first collimating lens 12a and passes through the first dichroic mirror 13a. The second laser beam LT2 emitted from the second light source unit 11b is collimated by the second collimating lens 12b and reflected by the first dichroic mirror 13a. The collimated first laser beam LT1 and the collimated second laser beam LT2 are wavelength-combined by the first dichroic mirror 13a. As a result, the light source 10 irradiates with laser beam LT, which is the combined laser beam of the collimated first laser beam LT1 and the collimated second laser beam LT2. The branching of the laser beam LT emitted from the light source 10 and its incidence into the first diffusion fiber 31 are substantially the same as in the light-emitting device 100, so a description is omitted.

[0034] The light-emitting device 100A can reduce costs compared to the light-emitting device 100 when red, green, or blue laser light is not required. The light-emitting device 100A is preferable, for example, in applications such as autonomous driving where only turquoise light emission is needed.

[0035] (Second modified example of the first embodiment) Figure 4 is an explanatory diagram showing a light-emitting device according to a second modified example of the first embodiment. As shown in Figure 4, the light-emitting device 100B according to the second modification of the first embodiment is substantially the same as the light-emitting device 100, except that the light source 10 is different.

[0036] In the light-emitting device 100B, the light source 10 includes a first light source section 11a and a first collimating lens 12a. In the light-emitting device 100B, the light source 10 does not include a second light source section 11b, a third light source section 11c, a second collimating lens 12b, a third collimating lens 12c, a first dichroic mirror 13a, or a second dichroic mirror 13b.

[0037] In the light-emitting device 100B, the first laser beam LT1 (laser beam LT) emitted from the first light source unit 11a is collimated by the first collimating lens 12a. As a result, the light source 10 is illuminated with the collimated first laser beam LT1 (laser beam LT). The branching of the laser beam LT emitted from the light source 10 and its incidence into the first diffusion fiber 31 are substantially the same as in the light-emitting device 100, so a detailed explanation is omitted.

[0038] The light-emitting device 100B can reduce costs compared to the light-emitting device 100 when a single color is sufficient. The light-emitting device 100B is preferable, for example, in taillight applications where only red light emission is required.

[0039] (Third modified example of the first embodiment) Figure 5 is an explanatory diagram showing a light-emitting device according to a third modified example of the first embodiment. As shown in Figure 5, the light-emitting device 100C according to the third modification of the first embodiment is substantially the same as the light-emitting device 100, except that the light source 10 is different.

[0040] In the light-emitting device 100C, the light source 10 includes a first light source section 11a, a second light source section 11b, a third light source section 11c, a first collimating lens 12a, a second collimating lens 12b, a third collimating lens 12c, a fourth collimating lens 12d, a fifth collimating lens 12e, a sixth collimating lens 12f, a first dichroic mirror 13a, a second dichroic mirror 13b, a first polarization multiplexing member 14a, a second polarization multiplexing member 14b, and a third polarization multiplexing member 14c. The first light source section 11a includes an S-polarized first light source section 11as and a P-polarized first light source section 11ap. The second light source section 11b includes an S-polarized second light source section 11bs and a P-polarized second light source section 11bp. The third light source unit 11c includes an S-polarized third light source unit 11cs and a P-polarized third light source unit 11cp.

[0041] The S-polarized first light source unit 11as emits S-polarized first laser beam LT1s. The P-polarized first light source unit 11ap emits P-polarized first laser beam LT1p. When the first laser beam LT1 is blue laser light, the S-polarized first laser beam LT1s is S-polarized blue laser light, and the P-polarized first laser beam LT1p is P-polarized blue laser light.

[0042] The S-polarized second light source unit 11bs emits S-polarized second laser light LT2s. The P-polarized second light source unit 11bp emits P-polarized second laser light LT2p. When the second laser light LT2 is green laser light, the S-polarized second laser light LT2s is S-polarized green laser light, and the P-polarized second laser light LT2p is P-polarized green laser light.

[0043] The S-polarized third light source unit 11cs emits S-polarized third laser light LT3s. The P-polarized third light source unit 11cp emits P-polarized third laser light LT3p. When the third laser light LT3 is red laser light, the S-polarized third laser light LT3s is S-polarized red laser light, and the P-polarized third laser light LT3p is P-polarized red laser light.

[0044] The first collimating lens 12a collimates the first laser beam LT1p which is P-polarized. The second collimating lens 12b collimates the first laser beam LT1s which is S-polarized. The third collimating lens 12c collimates the second laser beam LT2p which is P-polarized. The fourth collimating lens 12d collimates the second laser beam LT2s which is S-polarized. The fifth collimating lens 12e collimates the third laser beam LT3p which is P-polarized. The sixth collimating lens 12f collimates the third laser beam LT3s which is S-polarized.

[0045] The first polarization multiplexer 14a transmits the P-polarized first laser beam LT1p and reflects the S-polarized first laser beam LT1s. The second polarization multiplexer 14b transmits the P-polarized second laser beam LT2p and reflects the S-polarized second laser beam LT2s. The third polarization multiplexer 14c transmits the P-polarized third laser beam LT3p and reflects the S-polarized third laser beam LT3s.

[0046] In the light-emitting device 100C, the first laser beam LT1p, which is P-polarized and emitted from the first P-polarized light source 11ap, is collimated by the first collimating lens 12a and passes through the first polarization multiplexer 14a. The first laser beam LT1s, which is S-polarized and emitted from the first S-polarized light source 11as, is collimated by the second collimating lens 12b and reflected by the first polarization multiplexer 14a. The collimated first laser beam LT1s and the collimated first laser beam LT1p, which is P-polarized, are polarized and combined by the first polarization multiplexer 14a to form the first laser beam LT1. The second laser beam LT2p, which is P-polarized and emitted from the second P-polarized light source 11bp, is collimated by the third collimating lens 12c and passes through the second polarization multiplexer 14b. The S-polarized second laser beam LT2s emitted from the S-polarized second light source unit 11bs is collimated by the fourth collimating lens 12d and reflected by the second polarization multiplexer 14b. The collimated S-polarized second laser beam LT2s and the collimated P-polarized second laser beam LT2p are polarized and combined by the second polarization multiplexer 14b to form the second laser beam LT2. The P-polarized third laser beam LT3p emitted from the P-polarized third light source unit 11cp is collimated by the fifth collimating lens 12e and passes through the third polarization multiplexer 14c. The S-polarized third laser beam LT3s emitted from the S-polarized third light source unit 11cs is collimated by the sixth collimating lens 12f and reflected by the third polarization multiplexer 14c. The collimated S-polarized third laser beam LT3s and the collimated P-polarized third laser beam LT3p are polarized and combined by the third polarization multiplexer 14c to form the third laser beam LT3. The wavelength multiplexing of the first laser beam LT1, the second laser beam LT2, and the third laser beam LT3 is substantially the same as that of the light-emitting device 100, so no explanation is given. The light source 10 irradiates with laser beam LT, which is obtained by polarizing and combining the first laser beam LT1s (S-polarized) and the first laser beam LT1p (P-polarized), the second laser beam LT2 (S-polarized) and the second laser beam LT2p (P-polarized), and the third laser beam LT3 (S-polarized) and the third laser beam LT3p (P-polarized).When the first laser beam LT1 is blue laser light, the second laser beam LT2 is green laser light, and the third laser beam LT3 is red laser light, the light source 10 irradiates laser light LT which is obtained by wavelength-combining red combined laser light obtained by polarization-combining S-polarized red laser light and P-polarized red laser light, green combined laser light obtained by polarization-combining S-polarized green laser light and P-polarized green laser light, and blue combined laser light obtained by polarization-combining S-polarized blue laser light and P-polarized blue laser light. The branching of the laser light LT emitted from the light source 10 and its incidence into the first diffusion fiber 31 are substantially the same as those of the light-emitting device 100, so the explanation is omitted.

[0047] In this way, the light-emitting device 100C can emit laser light LT of various colors into the first diffusion fiber 31 by irradiating the first diffusion fiber 31 with laser light LT obtained by wavelength-combining polarized multiplexed red multiplexed laser light, polarized multiplexed green multiplexed laser light, and polarized multiplexed blue multiplexed laser light from the light source 10, thereby increasing the output of the laser light LT and adjusting it to the desired color tone.

[0048] (Fourth modified example of the first embodiment) Figure 6 is an explanatory diagram showing a light-emitting device according to a fourth modified example of the first embodiment. As shown in Figure 6, the light-emitting device 100D according to the fourth modification of the first embodiment is substantially the same as the light-emitting device 100C, except that the light source 10 is different.

[0049] In the light-emitting device 100D, the light source 10 includes a first light source section 11a, a second light source section 11b, a first collimating lens 12a, a second collimating lens 12b, a third collimating lens 12c, a fourth collimating lens 12d, a first dichroic mirror 13a, a first polarization multiplexing member 14a, and a second polarization multiplexing member 14b. The first light source section 11a includes an S-polarized first light source section (fourth light source section) 11as and a P-polarized first light source section (fifth light source section) 11ap. The second light source section 11b includes an S-polarized second light source section (sixth light source section) 11bs and a P-polarized second light source section (seventh light source section) 11bp. In the light-emitting device 100D, the light source 10 does not have a third light source section 11c, a fifth collimating lens 12e, a sixth collimating lens 12f, a second dichroic mirror 13b, or a third polarizing multiplexer 14c.

[0050] In the light-emitting device 100D, the first laser beam LT1p, which is P-polarized and emitted from the first P-polarized light source 11ap, is collimated by the first collimating lens 12a and passes through the first polarization multiplexer 14a. The first laser beam LT1s, which is S-polarized and emitted from the first S-polarized light source 11as, is collimated by the second collimating lens 12b and reflected by the first polarization multiplexer 14a. The collimated first laser beam LT1s and the collimated first laser beam LT1p are polarized and combined by the first polarization multiplexer 14a to form the first laser beam LT1. In other words, the first light source 11a polarizes and combines the first laser beam LT1s (S-polarized) and the first laser beam LT1p (P-polarized) and emits them. The second laser beam LT2p, which is P-polarized and emitted from the second P-polarized light source 11bp, is collimated by the third collimating lens 12c and passes through the second polarization multiplexing member 14b. The second laser beam LT2s, which is S-polarized and emitted from the second S-polarized light source 11bs, is collimated by the fourth collimating lens 12d and reflected by the second polarization multiplexing member 14b. The collimated S-polarized second laser beam LT2s and the collimated P-polarized second laser beam LT2p are polarized and combined by the second polarization multiplexing member 14b to become the second laser beam LT2. In other words, the second light source 11b polarizes and combines the S-polarized second laser beam LT2s and the P-polarized second laser beam LT2p and emits them. The wavelength combination of the first laser beam LT1 and the second laser beam LT2 is substantially the same as that of the light-emitting device 100, so the explanation is omitted. Light source 10 emits laser light LT, which is obtained by wavelength-combining a first laser beam LT1 obtained by polarization-combining an S-polarized first laser beam LT1s and a first laser beam LT1p, and a second laser beam LT2 obtained by polarization-combining an S-polarized second laser beam LT2s and a second laser beam LT2p. The branching of the laser light LT emitted from light source 10 and its incidence into the first diffusion fiber 31 are substantially the same as those of the light-emitting device 100, so a description is omitted.

[0051] The light-emitting device 100D can achieve the same effect as the light-emitting device 100A while increasing the output.

[0052] (Most modified example of the first embodiment) Figure 7 is an explanatory diagram showing a light-emitting device according to a fifth modified example of the first embodiment. As shown in Figure 7, the light-emitting device 100E according to the fifth modification of the first embodiment is substantially the same as the light-emitting device 100C, except that the light source 10 is different.

[0053] In the light-emitting device 100E, the light source 10 includes a first light source section 11a, a first collimating lens 12a, a second collimating lens 12b, and a first polarization multiplexing member 14a. The first light source section 11a includes an S-polarized first light source section 11as and a P-polarized first light source section 11ap. In the light-emitting device 100E, the light source 10 does not include a second light source section 11b, a third light source section 11c, a third collimating lens 12c, a fourth collimating lens 12d, a fifth collimating lens 12e, a sixth collimating lens 12f, a first dichroic mirror 13a, a second dichroic mirror 13b, a second polarization multiplexing member 14b, and a third polarization multiplexing member 14c.

[0054] In the light-emitting device 100E, the first laser beam LT1p, which is P-polarized and emitted from the first P-polarized light source 11ap, is collimated by the first collimating lens 12a and passes through the first polarization multiplexing member 14a. The first laser beam LT1s, which is S-polarized and emitted from the first S-polarized light source 11as, is collimated by the second collimating lens 12b and reflected by the first polarization multiplexing member 14a. The collimated S-polarized first laser beam LT1s and the collimated P-polarized first laser beam LT1p are polarized and combined by the first polarization multiplexing member 14a to form the first laser beam LT1 (laser beam LT). The wavelength multiplexing of the first laser beam LT1 (laser beam LT) is substantially the same as that of the light-emitting device 100, so the explanation is omitted. The light source 10 emits a first laser beam LT1 (laser beam LT) which is obtained by polarizing and combining a first laser beam LT1s with S polarization and a first laser beam LT1p with P polarization. The branching of the laser beam LT emitted from the light source 10 and its incidence into the first diffusion fiber 31 are substantially the same as those of the light-emitting device 100, so a detailed explanation is omitted.

[0055] The light-emitting device 100E can achieve the same effect as the light-emitting device 100B while increasing the output.

[0056] (Sixth variation of the first embodiment) Figure 8 is an explanatory diagram showing a light-emitting device according to a sixth modified example of the first embodiment. As shown in Figure 8, the light-emitting device 100F according to the sixth modification of the first embodiment is substantially the same as the light-emitting device 100, except that the light source 10 is different.

[0057] In the light-emitting device 100F, the light source 10 includes a first light source section 11a, a second light source section 11b, a third light source section 11c, a first collimating lens 12a, a second collimating lens 12b, a third collimating lens 12c, a fourth collimating lens 12d, a fifth collimating lens 12e, a sixth collimating lens 12f, a first dichroic mirror 13a, a second dichroic mirror 13b, a third dichroic mirror 13c, a fourth dichroic mirror 13d, and a first polarization multiplexing member 14a. The first light source section 11a includes an S-polarized first light source section 11as and a P-polarized first light source section 11ap. The second light source section 11b includes an S-polarized second light source section 11bs and a P-polarized second light source section 11bp. The third light source unit 11c includes an S-polarized third light source unit 11cs and a P-polarized third light source unit 11cp.

[0058] The first collimating lens 12a collimates the first laser beam LT1p which is P-polarized. The second collimating lens 12b collimates the second laser beam LT2p which is P-polarized. The third collimating lens 12c collimates the third laser beam LT3p which is P-polarized. The fourth collimating lens 12d collimates the first laser beam LT1s which is S-polarized. The fifth collimating lens 12e collimates the second laser beam LT2s which is S-polarized. The sixth collimating lens 12f collimates the third laser beam LT3s which is S-polarized.

[0059] The first dichroic mirror 13a transmits the first laser beam LT1p which is P-polarized and reflects the second laser beam LT2p which is P-polarized. The second dichroic mirror 13b transmits the first laser beam LT1p which is P-polarized and the second laser beam LT2p which is P-polarized, and reflects the third laser beam LT3p which is P-polarized. The third dichroic mirror 13c transmits the first laser beam LT1s which is S-polarized and reflects the second laser beam LT2s which is S-polarized. The second dichroic mirror 13b transmits the first laser beam LT1s which is S-polarized and the second laser beam LT2s which is S-polarized, and reflects the third laser beam LT3s which is S-polarized.

[0060] The first polarization multiplexing member 14a transmits the first laser beam LT1p, the second laser beam LT2p, and the third laser beam LT3p, which are P-polarized, and reflects the first laser beam LT1s, the second laser beam LT2s, and the third laser beam LT3s, which are S-polarized.

[0061] In the light-emitting device 100F, the first P-polarized laser beam LT1p emitted from the first P-polarized light source 11ap is collimated by the first collimating lens 12a and passes through the first dichroic mirror 13a. The second P-polarized laser beam LT2p emitted from the second P-polarized light source 11bp is collimated by the second collimating lens 12b and reflected by the first dichroic mirror 13a. The collimated first P-polarized laser beam LT1p and the collimated second P-polarized laser beam LT2p are wavelength-combined by the first dichroic mirror 13a. The laser beam obtained by combining the first P-polarized laser beam LT1p and the second P-polarized laser beam LT2p passes through the second dichroic mirror 13b. The P-polarized third laser beam LT3p emitted from the P-polarized third light source unit 11cp is collimated by the third collimating lens 12c and reflected by the second dichroic mirror 13b. The laser beam obtained by combining the P-polarized first laser beam LT1p and the P-polarized second laser beam LT2p, and the collimated P-polarized third laser beam LT3p are wavelength-combined by the second dichroic mirror 13b to form the first combined laser beam LCa. The first combined laser beam LCa passes through the first polarization combined member 14a. The S-polarized first laser beam LT1s emitted from the S-polarized first light source unit 11as is collimated by the fourth collimating lens 12d and passes through the third dichroic mirror 13c. The S-polarized second laser beam LT2s emitted from the S-polarized second light source unit 11bs is collimated by the fifth collimating lens 12e and reflected by the third dichroic mirror 13c. The collimated S-polarized first laser beam LT1s and the collimated S-polarized second laser beam LT2s are wavelength-combined by the third dichroic mirror 13c. The laser beam obtained by combining the S-polarized first laser beam LT1s and the S-polarized second laser beam LT2s passes through the fourth dichroic mirror 13d. The S-polarized third laser beam LT3s emitted from the S-polarized third light source unit 11cs is collimated by the sixth collimating lens 12f and reflected by the fourth dichroic mirror 13d.The laser light obtained by combining the S-polarized first laser beam LT1s and the S-polarized second laser beam LT2s, along with the collimated S-polarized third laser beam LT3s, is wavelength-combined by the fourth dichroic mirror 13d to form the second combined laser beam LCb. The second combined laser beam LCb is reflected by the first polarization-combining member 14a. The first combined laser beam LCa and the second combined laser beam LCb are polarization-combined by the first polarization-combining member 14a. As a result, the light source 10 irradiates with laser light LT obtained by polarization-combining the first combined laser beam LCa, which is obtained by wavelength-combining the P-polarized first laser beam LT1p, the P-polarized second laser beam LT2p, and the P-polarized third laser beam LT3p, and the second combined laser beam LCb, which is obtained by wavelength-combining the S-polarized first laser beam LT1s, the S-polarized second laser beam LT2s, and the S-polarized third laser beam LT3s. For example, if the first S-polarized laser beam LT1s is an S-polarized blue laser beam, the first P-polarized laser beam LT1p is a P-polarized blue laser beam, the second S-polarized laser beam LT2s is an S-polarized green laser beam, the second P-polarized laser beam LT2p is a P-polarized green laser beam, the third S-polarized laser beam LT3s is an S-polarized red laser beam, and the third P-polarized laser beam LT3p is a P-polarized red laser beam, then the light source 10 irradiates the light source 10 with a first combined laser beam LCa, which is obtained by wavelength-combining the P-polarized red laser beam, the P-polarized green laser beam, and the P-polarized blue laser beam, and a second combined laser beam LCb, which is obtained by wavelength-combining the S-polarized red laser beam, the S-polarized green laser beam, and the S-polarized blue laser beam, and the resulting laser beam LT. The branching of the laser beam LT emitted from the light source 10 and its incidence into the first diffusion fiber 31 are substantially the same as those of the light-emitting device 100, so the explanation is omitted.

[0062] In this way, the light-emitting device 100F can emit laser light LT of various colors by irradiating the first diffusion fiber 31 with a first multiplexed laser beam LCa and a second multiplexed laser beam LCb, which are wavelength-combined and polarized together, from the light source 10. This increases the output of the laser light LT and adjusts its color to a desired tone.

[0063] (Seventh modified example of the first embodiment) Figure 9 is an explanatory diagram showing a light-emitting device according to a seventh modified example of the first embodiment. As shown in Figure 9, the light-emitting device 100G according to the seventh modification of the first embodiment is substantially the same as the light-emitting device 100F, except that the light source 10 is different.

[0064] In the light-emitting device 100G, the light source 10 includes a first light source section 11a, a second light source section 11b, a first collimating lens 12a, a second collimating lens 12b, a fourth collimating lens 12d, a fifth collimating lens 12e, a first dichroic mirror 13a, a third dichroic mirror 13c, and a first polarization multiplexing member 14a. The first light source section 11a includes an S-polarized first light source section (fourth light source section) 11as and a P-polarized first light source section 11ap (fifth light source section). The second light source section 11b includes an S-polarized second light source section (sixth light source section) 11bs and a P-polarized second light source section (seventh light source section) 11bp. In the light-emitting device 100G, the light source 10 does not have a third light source section 11c, a third collimating lens 12c, a sixth collimating lens 12f, a second dichroic mirror 13b, or a fourth dichroic mirror 13d.

[0065] In the light-emitting device 100G, the first P-polarized laser beam LT1p emitted from the first P-polarized light source 11ap is collimated by the first collimating lens 12a and passes through the first dichroic mirror 13a. The second P-polarized laser beam LT2p emitted from the second P-polarized light source 11bp is collimated by the second collimating lens 12b and reflected by the first dichroic mirror 13a. The collimated first P-polarized laser beam LT1p and the collimated second P-polarized laser beam LT2p are wavelength-combined by the first dichroic mirror 13a. The wavelength-combination of the first P-polarized laser beam LT1p and the second P-polarized laser beam LT2p by the first dichroic mirror 13a results in the first combined laser beam LCa. The first light source unit 11a emits a first combined laser beam LCa, obtained by wavelength-combining a first P-polarized laser beam LT1p and a second P-polarized laser beam LT2p, toward the first polarization multiplexing member 14a. The first combined laser beam LCa passes through the first polarization multiplexing member 14a. The first S-polarized laser beam LT1s emitted from the first S-polarized light source unit 11as is collimated by the fourth collimating lens 12d and passes through the third dichroic mirror 13c. The second S-polarized laser beam LT2s emitted from the second S-polarized light source unit 11bs is collimated by the fifth collimating lens 12e and reflected by the third dichroic mirror 13c. The collimated first S-polarized laser beam LT1s and the collimated second S-polarized laser beam LT2s are wavelength-combined by the third dichroic mirror 13c. The S-polarized first laser beam LT1s and the S-polarized second laser beam LT2s are wavelength-combined by the third dichroic mirror 13c to form the second combined laser beam LCb. The second light source unit 11b emits the second combined laser beam LCb, which is obtained by wavelength-combining the S-polarized first laser beam LT1s and the S-polarized second laser beam LT2s, toward the first polarization-combining member 14a. The second combined laser beam LCb is reflected by the first polarization-combining member 14a. The first combined laser beam LCa and the second combined laser beam LCb are polarization-combined by the first polarization-combining member 14a.As a result, the light source 10 emits a laser beam LT which is obtained by combining the wavelengths of a first P-polarized laser beam LT1p and a second P-polarized laser beam LT2p to form a first combined laser beam LCa, and a second combined laser beam LCb which is obtained by combining the wavelengths of a first S-polarized laser beam LT1s and a second S-polarized laser beam LT2s. The branching of the laser beam LT emitted from the light source 10 and its incidence into the first diffusion fiber 31 are substantially the same as those of the light-emitting device 100, so a detailed explanation is omitted.

[0066] The light-emitting device 100G achieves the same effect as the light-emitting device 100A while increasing the output.

[0067] (Second Embodiment) Figure 10 is an explanatory diagram showing a light-emitting device according to the second embodiment. As shown in Figure 10, the light-emitting device 200 according to the second embodiment is substantially the same as the light-emitting device 100, except that the second optical member 22 is different and it further includes a light-receiving element 50.

[0068] In the light-emitting device 200, the second optical element 22 splits the second branched laser beam LTB2 into a third branched laser beam LTB3 and a fourth branched laser beam LTB4. The second optical element 22 reflects the third branched laser beam LTB3 and transmits the fourth branched laser beam LTB4. In the light-emitting device 200, the second optical element 22 is, for example, a beam splitter.

[0069] The irradiation of laser light LT from the light source 10 is substantially the same as that of the light-emitting device 100, so the explanation is omitted. In the light-emitting device 200, the laser light LT emitted from the light source 10 is branched into a first branched laser beam LTB1 and a second branched laser beam LTB2 in the first optical member 21. The first branched laser beam LTB1 is focused by the first focusing lens 41 and incident on the first end 31a of the first diffusion fiber 31. The first branched laser beam LTB1 incident from the first end 31a passes through the first intermediate section 31c and heads toward the second end 31b. A portion of the first branched laser beam LTB1 incident from the first end 31a is emitted, for example, from the second end 31b. The second branched laser beam LTB2 is branched into a third branched laser beam LTB3 and a fourth branched laser beam LTB4 in the second optical member 22. The third branched laser beam LTB3 is reflected by the second optical member 22, focused by the second focusing lens 42, and incident on the second end 31b of the first diffusion fiber 31. The third branched laser beam LTB3 is the portion of the second branched laser beam LTB2 that is reflected by the second optical member 22. The third branched laser beam LTB3 incident from the second end 31b passes through the first intermediate section 31c and heads towards the first end 31a. A portion of the third branched laser beam LTB3 incident from the second end 31b is emitted, for example, from the first end 31a. The fourth branched laser beam LTB4 passes through the second optical member 22 and is incident on the photodetector 50. The fourth branched laser beam LTB4 is the portion of the second branched laser beam LTB2 that is transmitted through the second optical member 22. The fourth branch laser beam LTB4 is, for example, 10% or less of the second branch laser beam LTB2, and preferably 5% or less of the second branch laser beam LTB2.

[0070] (Photodetector) The light-receiving element 50 detects the presence or absence of incidence of the fourth-branched laser beam LTB4 and the intensity of the incident fourth-branched laser beam LTB4. The light-receiving element 50 is, for example, a photodiode or a phototransistor. Preferably, the light-receiving element 50 is capable of independently measuring the output of each RGB color. Using such a light-receiving element 50 enables detailed color tuning. The light-receiving element 50 outputs the detection result to a control device (not shown). The control device controls the operation of the light source 10 based on the detection result. For example, if there is no incidence of the fourth-branched laser beam LTB4 on the light-receiving element 50, the control device stops the emission of laser beam LT from the light source 10.

[0071] In this way, the light-emitting device 200 can detect malfunctions by injecting the fourth branch laser beam LTB4, which is part of the second branch laser beam LTB2, into the photodetector 50. Furthermore, if there is a malfunction in the light-emitting device 200, the safety of the light-emitting device 200 can be improved by stopping the emission of laser beam LT from the light source 10.

[0072] (Third embodiment) Figure 11 is an explanatory diagram showing a light-emitting device according to the third embodiment. As shown in Figure 11, the light-emitting device 300 according to the third embodiment is substantially the same as the light-emitting device 100, except that it further comprises a light-receiving element 50.

[0073] The irradiation of laser light LT from the light source 10 is substantially the same as that of the light-emitting device 100, so the explanation is omitted. In the light-emitting device 300, the laser light LT emitted from the light source 10 is branched into a first branched laser light LTB1 and a second branched laser light LTB2 in the first optical member 21. The first branched laser light LTB1 is focused by the first focusing lens 41 and incident on the first end 31a of the first diffusion fiber 31. The first branched laser light LTB1 incident from the first end 31a passes through the first intermediate section 31c and heads toward the second end 31b. A portion of the first branched laser light LTB1 incident from the first end 31a is emitted from the second end 31b. A portion of the first branched laser light LTB1 emitted from the second end 31b is reflected by the second optical member 22 toward the first optical member 21, and is further reflected by the first optical member 21 before being incident on the light-receiving element 50. Of the first branched laser beam LTB1 emitted from the second end 31b, 10% or less, preferably 5% or less, is reflected by the first optical member 21 and incident on the photodetector 50. The second branched laser beam LTB2 is reflected by the second optical member 22, focused by the second focusing lens 42, and incident on the second end 31b of the first diffusion fiber 31. The second branched laser beam LTB2 incident from the second end 31b passes through the first intermediate section 31c and heads towards the first end 31a. A portion of the second branched laser beam LTB2 incident from the second end 31b is emitted from the first end 31a. A portion of the second branched laser beam LTB2 emitted from the first end 31a passes through the first optical member 21 and incident on the photodetector 50. Of the second branched laser beam LTB2 emitted from the first end portion 31a, 10% or less, preferably 5% or less, passes through the first optical member 21 and is incident on the light-receiving element 50.

[0074] (Photodetector) The light-receiving element 50 detects whether a portion of the first branched laser beam LTB1 and a portion of the second branched laser beam LTB2 are incident on the light-receiving element, and the intensity of the incident portion of the first branched laser beam LTB1 and a portion of the second branched laser beam LTB2. The light-receiving element 50 is, for example, a photodiode or a phototransistor. The light-receiving element 50 outputs the detection result to a control device (not shown). The control device controls the operation of the light source 10 based on the detection result. For example, if there is no incident on the light-receiving element 50 of the first branched laser beam LTB1 and a portion of the second branched laser beam LTB2, the control device stops the emission of laser beam LT from the light source 10.

[0075] In this way, the light-emitting device 300 can detect malfunctions by directing a portion of the first branched laser beam LTB1 and a portion of the second branched laser beam LTB2 into the photodetector 50. Furthermore, if there is a malfunction in the light-emitting device 300, the safety of the light-emitting device 300 can be improved by stopping the emission of laser beam LT from the light source 10. The light-emitting device 300 can monitor the output via the first diffusion fiber 31, so it can detect abnormalities, for example, when the first diffusion fiber 31 is damaged.

[0076] (Fourth Embodiment) Figure 12 is an explanatory diagram showing a light-emitting device according to the fourth embodiment. As shown in Figure 12, the light-emitting device 400 according to the fourth embodiment is substantially the same as the light-emitting device 100, except that it further comprises a polarizing member 60.

[0077] The irradiation of laser light LT from the light source 10 is substantially the same as that of the light-emitting device 100, so the explanation is omitted. In the light-emitting device 400, the light source 10 irradiates, for example, S-polarized laser light LT. The laser light LT emitted from the light source 10 is split into a first branched laser light LTB1 and a second branched laser light LTB2 in the first optical member 21. The first branched laser light LTB1 is focused by the first focusing lens 41 and incident on the first end 31a of the first diffusion fiber 31. The first branched laser light LTB1 incident from the first end 31a passes through the first intermediate section 31c and heads toward the second end 31b. A portion of the first branched laser light LTB1 incident from the first end 31a is emitted from the second end 31b. A portion of the first branched laser beam LTB1 emitted from the second end 31b is reflected by the second optical member 22, passes through the first optical member 21, and heads toward the light source 10. The second branched laser beam LTB2 is reflected by the second optical member 22, focused by the second focusing lens 42, and incident on the second end 31b of the first diffusion fiber 31. The second branched laser beam LTB2 incident from the second end 31b passes through the first intermediate section 31c and heads toward the first end 31a. A portion of the second branched laser beam LTB2 incident from the second end 31b is emitted from the first end 31a. A portion of the second branched laser beam LTB2 emitted from the first end 31a is reflected by the first optical member 21 and heads toward the light source 10. In this way, a portion of the first branched laser beam LTB1 and a portion of the second branched laser beam LTB2 may head toward the light source 10 from the first optical member 21.

[0078] (Polarizing material) The polarizing member 60 is positioned between the light source 10 and the first optical member 21. The polarizing member 60 transmits the S-polarized component of a portion of the first branched laser beam LTB1 and a portion of the second branched laser beam LTB2, and reflects the P-polarized component. This blocks the P-polarized component of a portion of the first branched laser beam LTB1 and a portion of the second branched laser beam LTB2 that travels from the first optical member 21 towards the light source 10. The laser beam LT emitted from the light source 10 is S-polarized, so it passes through the polarizing member 60.

[0079] Thus, by further providing a polarizing member 60 positioned between the light source 10 and the first optical member 21, the occurrence of COD (Catastrophic Optical Damage) caused by a portion of the first branched laser beam LTB1 and a portion of the second branched laser beam LTB2 reaching the light source 10 can be reduced.

[0080] The light source 10 may also be irradiated with P-polarized laser light LT. In this case, the polarizing member 60 transmits the P-polarized component of a portion of the first branched laser light LTB1 and a portion of the second branched laser light LTB2, and reflects the S-polarized component. Since the laser light LT irradiated from the light source 10 is P-polarized, it passes through the polarizing member 60. The polarizing member 60 should transmit the same polarization component as the laser light LT irradiated from the light source 10 and reflect the different polarization component.

[0081] (Fifth embodiment) Figure 13 is an explanatory diagram showing a light-emitting device according to the fifth embodiment. As shown in Figure 13, the light-emitting device 500 according to the fifth embodiment is substantially the same as the light-emitting device 100, except that it has a different second optical member 22 and further comprises a third optical member 23, a fourth optical member 24, a second diffusion fiber 32, a third condensing lens 43, and a fourth condensing lens 44.

[0082] In the light-emitting device 500, the second optical element 22 splits the second branched laser beam LTB2 into a third branched laser beam LTB3 and a fourth branched laser beam LTB4. The second optical element 22 reflects the third branched laser beam LTB3 and transmits the fourth branched laser beam LTB4. In the light-emitting device 500, the second optical element 22 is, for example, a beam splitter.

[0083] (Third optical component) The third optical element 23 splits the fourth branched laser beam LTB4 into the fifth branched laser beam LTB5 and the sixth branched laser beam LTB6. The third optical element 23 reflects the fifth branched laser beam LTB5 and transmits the sixth branched laser beam LTB6. The third optical element 23 is, for example, a beam splitter.

[0084] (Fourth optical component) The fourth optical element 24 reflects at least a portion of the sixth branched laser beam LTB6. In the light-emitting device 500, the fourth optical element 24 is a mirror that reflects all of the sixth branched laser beam LTB6.

[0085] (Second diffusion fiber) The second diffusion fiber 32 has a third end 32a, a fourth end 32b, and a second intermediate portion 32c. The third end 32a is located at one end of the second diffusion fiber 32. The fourth end 32b is located at the other end of the second diffusion fiber 32. The second intermediate portion 32c is located between the third end 32a and the fourth end 32b. The fifth branched laser beam LTB5, reflected by the third optical member 23, is incident on the third end 32a. The sixth branched laser beam LTB6, reflected by the fourth optical member 24, is incident on the fourth end 32b.

[0086] The third end 32a has a third incident surface 32a1 into which the fifth branched laser beam LTB5 is incident. The fourth end 32b has a fourth incident surface 32b1 into which the sixth branched laser beam LTB6 is incident. In the light-emitting device 500, the third incident surface 32a1 and the fourth incident surface 32b1 are arranged to face the same direction. The distance D2 between the center of the third incident surface 32a1 and the center of the fourth incident surface 32b1 is, for example, between 1 mm and 100 mm.

[0087] (Third and fourth focusing lenses) The third focusing lens 43 focuses the fifth branched laser beam LTB5 and directs it into the third end 32a of the second diffusion fiber 32. The fourth focusing lens 44 focuses the sixth branched laser beam LTB6 and directs it into the fourth end 32b of the second diffusion fiber 32.

[0088] The irradiation of laser light LT from the light source 10 is substantially the same as that of the light-emitting device 100, so the explanation is omitted. In the light-emitting device 500, the laser light LT emitted from the light source 10 is branched into a first branched laser beam LTB1 and a second branched laser beam LTB2 in the first optical member 21. The first branched laser beam LTB1 is focused by the first focusing lens 41 and incident on the first end 31a of the first diffusion fiber 31. The first branched laser beam LTB1 incident from the first end 31a passes through the first intermediate section 31c and heads toward the second end 31b. A portion of the first branched laser beam LTB1 incident from the first end 31a is emitted, for example, from the second end 31b. The second branched laser beam LTB2 is branched into a third branched laser beam LTB3 and a fourth branched laser beam LTB4 in the second optical member 22. The third branched laser beam LTB3 is reflected by the second optical member 22, focused by the second focusing lens 42, and incident on the second end 31b of the first diffusion fiber 31. The third branched laser beam LTB3 is the portion of the second branched laser beam LTB2 that is reflected by the second optical member 22. The third branched laser beam LTB3 that entered from the second end 31b passes through the first intermediate section 31c and heads toward the first end 31a. A portion of the third branched laser beam LTB3 that entered from the second end 31b is emitted, for example, from the first end 31a. The fourth branched laser beam LTB4 is branched in the third optical member 23 into the fifth branched laser beam LTB5 and the sixth branched laser beam LTB6. The fifth branched laser beam LTB5 is reflected by the third optical member 23, focused by the third focusing lens 43, and incident on the third end 32a of the second diffusion fiber 32. The fifth branched laser beam LTB5 is the portion of the fourth branched laser beam LTB4 that is reflected by the third optical member 23. The fifth branched laser beam LTB5, incident from the third end 32a, passes through the second intermediate section 32c and heads toward the fourth end 32b. A portion of the fifth branched laser beam LTB5 incident from the third end 32a is emitted, for example, from the fourth end 32b. The sixth branched laser beam LTB6 is reflected by the fourth optical member 24, focused by the fourth focusing lens 44, and incident on the fourth end 32b of the second diffusion fiber 32. The sixth branched laser beam LTB6, incident from the fourth end 32b, passes through the second intermediate section 32c and heads toward the third end 32a.A portion of the sixth branched laser beam LTB6, which is incident from the fourth end 32b, is emitted from, for example, the third end 32a.

[0089] In this way, the light-emitting device 500 branches the laser light LT emitted from the light source 10 into a first branched laser beam LTB1, a third branched laser beam LTB3, a fifth branched laser beam LTB5, and a sixth branched laser beam LTB6, and directs them into the first end 31a and second end 31b of the first diffusion fiber 31, and the third end 32a and fourth end 32b of the second diffusion fiber 32, respectively. This allows the first diffusion fiber 31 and the second diffusion fiber 32 to be illuminated more uniformly compared to the case where the laser light is directed from only one end of the first diffusion fiber 31 or the second diffusion fiber 32. The arrangement of the ends of the first diffusion fiber 31 and the second diffusion fiber 32 may be changed, and the laser light directed into each end may be changed. For example, the third branched laser beam LTB3 may be directed into the third end 32a of the second diffusion fiber 32, and the fifth branched laser beam LTB5 may be directed into the second end 31b of the first diffusion fiber 31.

[0090] (Sixth Embodiment) Figure 14 is an explanatory diagram showing a light-emitting device according to the sixth embodiment. As shown in Figure 14, the light-emitting device 600 according to the sixth embodiment includes a first light source 10x, a second light source 10y, a first optical member 21, a second optical member 22, a third optical member 23, a fourth optical member 24, a first diffusion fiber 31, a second diffusion fiber 32, a first condensing lens 41, a second condensing lens 42, a third condensing lens 43, and a fourth condensing lens 44.

[0091] (1st, 2nd light source) The first light source 10x emits laser light LTx. The first light source 10x includes a first light source section 11a, a second light source section 11b, a third light source section 11c, a first collimating lens 12a, a second collimating lens 12b, a third collimating lens 12c, a first dichroic mirror 13a, and a second dichroic mirror 13b. Since each component included in the first light source 10x is substantially the same as that of the light source 10 described above, a description is omitted.

[0092] The second light source 10y emits laser light LTy. The second light source 10y includes a fourth light source section 11d, a fifth light source section 11e, a sixth light source section 11f, a fourth collimating lens 12d, a fifth collimating lens 12e, a sixth collimating lens 12f, a third dichroic mirror 13c, and a fourth dichroic mirror 13d.

[0093] The fourth light source unit 11d emits a fourth laser beam LT4. The fourth laser beam LT4 has a fourth peak wavelength. The fourth laser beam LT4 is, for example, blue laser light. The fourth peak wavelength is, for example, 400 nm or more and less than 500 nm. The fourth peak wavelength may be, for example, the same as the first peak wavelength, or it may be different from the first peak wavelength. It is preferable that the fourth peak wavelength is different from the first peak wavelength. When the fourth peak wavelength is different from the first peak wavelength, by using a first dichroic mirror 13a and a second dichroic mirror 13b that transmit the first laser beam LT1 and reflect the fourth laser beam LT4, and by using a third dichroic mirror 13c and a fourth dichroic mirror 13d that transmit the fourth laser beam LT4 and reflect the first laser beam LT1, the generation of COD can be reduced with a simple configuration, similar to the light-emitting device 600B according to the second modification of the sixth embodiment described later. The fourth laser beam LT4 may be a green laser beam or a red laser beam.

[0094] The fifth light source unit 11e emits the fifth laser beam LT5. The fifth laser beam LT5 has a fifth peak wavelength. The fifth peak wavelength is different from the fourth peak wavelength. The fifth laser beam LT5 is, for example, green laser light. The fifth peak wavelength is, for example, 500 nm or more and less than 600 nm. The fifth peak wavelength may be, for example, the same as the second peak wavelength, or it may be different from the second peak wavelength. The fifth light source unit 11e is, for example, a laser diode. It is preferable that the fifth peak wavelength is different from the second peak wavelength. When the fifth peak wavelength is different from the second peak wavelength, by using a second dichroic mirror 13b that transmits the second laser beam LT2 and reflects the fifth laser beam LT5, and a fourth dichroic mirror 13d that transmits the fifth laser beam LT5 and reflects the second laser beam LT2, the generation of COD can be reduced with a simple configuration, similar to the light-emitting device 600B according to the second modification of the sixth embodiment described later. The fifth laser beam LT5 may be a blue laser beam or a red laser beam.

[0095] The sixth light source unit 11f emits the sixth laser light LT6. The sixth laser light LT6 has a sixth peak wavelength. The sixth peak wavelength is different from the fourth and fifth peak wavelengths. The sixth laser light LT6 is, for example, red laser light. The sixth peak wavelength is, for example, 600 nm or more and 700 nm or less. The sixth peak wavelength may be, for example, the same as the third peak wavelength, or it may be different from the third peak wavelength. The sixth light source unit 11f is, for example, a laser diode. It is preferable that the sixth peak wavelength is different from the third peak wavelength. The sixth laser light LT6 may be blue laser light or green laser light.

[0096] The fourth collimating lens 12d collimates the fourth laser beam LT4. The fifth collimating lens 12e collimates the fifth laser beam LT5. The sixth collimating lens 12f collimates the sixth laser beam LT6.

[0097] The third dichroic mirror 13c transmits the fourth laser beam LT4 and reflects the fifth laser beam LT5. The fourth dichroic mirror 13d transmits the fourth laser beam LT4 and the fifth laser beam LT5 and reflects the sixth laser beam LT6.

[0098] (Optical components 1 to 4) The first optical element 21 splits the laser beam LTx into a first branched laser beam LTB1 and a second branched laser beam LTB2. The first optical element 21 reflects the first branched laser beam LTB1 and transmits the second branched laser beam LTB2. The first optical element 21 is, for example, a beam splitter.

[0099] The second optical element 22 reflects at least a portion of the second branched laser beam LTB2. In the light-emitting device 600, the second optical element 22 is a mirror that reflects all of the second branched laser beam LTB2.

[0100] The third optical element 23 splits the laser beam LTy into a third branched laser beam LTB3 and a fourth branched laser beam LTB4. The third optical element 23 reflects the third branched laser beam LTB3 and transmits the fourth branched laser beam LTB4. The third optical element 23 is, for example, a beam splitter.

[0101] The fourth optical element 24 reflects at least a portion of the fourth branched laser beam LTB4. In the light-emitting device 600, the fourth optical element 24 is a mirror that reflects all of the fourth branched laser beam LTB4.

[0102] (First and second diffusion fibers) The first diffusion fiber 31 has a first end 31a, a second end 31b, and a first intermediate portion 31c. The first end 31a is located at one end of the first diffusion fiber 31 (the end on the first light source 10x side). The second end 31b is located at the other end of the first diffusion fiber 31 (the end on the second light source 10y side). The first intermediate portion 31c is located between the first end 31a and the second end 31b. The first branched laser beam LTB1 reflected by the first optical member 21 is incident on the first end 31a. The fourth branched laser beam LTB4 reflected by the fourth optical member 24 is incident on the second end 31b.

[0103] The second diffusion fiber 32 has a third end 32a, a fourth end 32b, and a second intermediate portion 32c. The third end 32a is located at one end of the second diffusion fiber 32 (the end on the first light source 10x side). The fourth end 32b is located at the other end of the second diffusion fiber 32 (the end on the second light source 10y side). The second intermediate portion 32c is located between the third end 32a and the fourth end 32b. The second branched laser beam LTB2, reflected by the second optical member 22, is incident on the third end 32a. The third branched laser beam LTB3, reflected by the third optical member 23, is incident on the fourth end 32b.

[0104] (1st to 4th condensing lenses) The first focusing lens 41 focuses the first branched laser beam LTB1 and directs it into the first end 31a of the first diffusion fiber 31. The second focusing lens 42 focuses the second branched laser beam LTB2 and directs it into the third end 32a of the second diffusion fiber 32. The third focusing lens 43 focuses the third branched laser beam LTB3 and directs it into the fourth end 32b of the second diffusion fiber 32. The fourth focusing lens 44 focuses the fourth branched laser beam LTB4 and directs it into the second end 31b of the first diffusion fiber 31.

[0105] The first light source 10x irradiates with laser light LTx, which is obtained by combining the first laser light LT1, the second laser light LT2, and the third laser light LT3. The irradiation of laser light LTx from the first light source 10x is substantially the same as the irradiation of laser light LT from the light source 10 described above, so the explanation is omitted. In the light-emitting device 600, the fourth laser light LT4 emitted from the fourth light source unit 11d is collimated by the fourth collimating lens 12d and passes through the third dichroic mirror 13c. The fifth laser light LT5 emitted from the fifth light source unit 11e is collimated by the fifth collimating lens 12e and reflected by the third dichroic mirror 13c. The collimated fourth laser light LT4 and the collimated fifth laser light LT5 are wavelength-combined by the third dichroic mirror 13c. The laser beam obtained by combining the fourth laser beam LT4 and the fifth laser beam LT5 passes through the fourth dichroic mirror 13d. The sixth laser beam LT6 emitted from the sixth light source 11f is collimated by the sixth collimating lens 12f and reflected by the fourth dichroic mirror 13d. The laser beam obtained by combining the fourth laser beam LT4 and the fifth laser beam LT5, and the collimated sixth laser beam LT6, are wavelength-combined by the fourth dichroic mirror 13d. As a result, the second light source 10y irradiates with laser beam LTy, which is obtained by combining the fourth laser beam LT4, the fifth laser beam LT5, and the sixth laser beam LT6. For example, if the fourth laser beam LT4 is blue laser light, the fifth laser beam LT5 is green laser light, and the sixth laser beam LT6 is red laser light, then the second light source 10y will irradiate with laser light LTy, which is obtained by wavelength combination of the red laser light, the green laser light, and the blue laser light.

[0106] The laser beam LTx emitted from the first light source 10x is split in the first optical member 21 into a first branched laser beam LTB1 and a second branched laser beam LTB2. The first branched laser beam LTB1 is focused by the first focusing lens 41 and incident on the first end 31a of the first diffusion fiber 31. The first branched laser beam LTB1 incident from the first end 31a passes through the first intermediate section 31c and heads toward the second end 31b. A portion of the first branched laser beam LTB1 incident from the first end 31a is emitted, for example, from the second end 31b. The second branched laser beam LTB2 is reflected by the second optical member 22, focused by the second focusing lens 42, and incident on the third end 32a of the second diffusion fiber 32. The second branched laser beam LTB2 incident from the third end 32a passes through the second intermediate section 32c and heads toward the fourth end 32b. A portion of the second branched laser beam LTB2 incident from the third end 32a is emitted, for example, from the fourth end 32b. The laser beam LTy emitted from the second light source 10y is branched in the third optical member 23 into the third branched laser beam LTB3 and the fourth branched laser beam LTB4. The third branched laser beam LTB3 is focused by the third focusing lens 43 and incident on the fourth end 32b of the second diffusion fiber 32. The third branched laser beam LTB3 incident from the fourth end 32b passes through the second intermediate section 32c and heads towards the third end 32a. A portion of the third branched laser beam LTB3 incident from the fourth end 32b is emitted, for example, from the third end 32a. The fourth branched laser beam LTB4 is reflected by the fourth optical member 24, focused by the fourth focusing lens 44, and incident on the second end 31b of the first diffusion fiber 31. The fourth branched laser beam LTB4, incident from the second end 31b, passes through the first intermediate section 31c and heads toward the first end 31a. A portion of the fourth branched laser beam LTB4 incident from the second end 31b is emitted, for example, from the first end 31a.

[0107] In this way, the light-emitting device 600 splits the laser light LTx emitted from the first light source 10x into a first branched laser light LTB1 and a second branched laser light LTB2, and directs them into the first end 31a of the first diffusion fiber 31 and the third end 32a of the second diffusion fiber 32, respectively. Similarly, the laser light LTy emitted from the second light source 10y is split into a third branched laser light LTB3 and a fourth branched laser light LTB4, and directs them into the fourth end 32b of the second diffusion fiber 32 and the second end 31b of the first diffusion fiber 31, respectively. This allows laser light of different colors to be directed into both ends of the first diffusion fiber 31 and the second diffusion fiber 32. As a result, the first diffusion fiber 31 and the second diffusion fiber 32 can be illuminated in a gradient.

[0108] (First modified example of the sixth embodiment) Figure 15 is an explanatory diagram showing a light-emitting device according to the first modified example of the sixth embodiment. As shown in Figure 15, the light-emitting device 600A according to the first modified example of the sixth embodiment is substantially the same as the light-emitting device 600, except that it further comprises a first light-receiving element 51 and a second light-receiving element 52.

[0109] The irradiation of laser light LTx from the first light source 10x and laser light LTy from the second light source 10y is substantially the same as in the light-emitting device 600, so a description is omitted. In the light-emitting device 600A, the laser light LTx emitted from the first light source 10x is branched into a first branched laser light LTB1 and a second branched laser light LTB2 in the first optical member 21. The first branched laser light LTB1 is focused by the first focusing lens 41 and incident on the first end 31a of the first diffusion fiber 31. The first branched laser light LTB1 incident from the first end 31a passes through the first intermediate section 31c and heads toward the second end 31b. A portion of the first branched laser light LTB1 incident from the first end 31a is emitted from the second end 31b. A portion of the first branched laser beam LTB1 emitted from the second end 31b is reflected by the fourth optical member 24 toward the third optical member 23, and is further reflected by the third optical member 23 before entering the second photodetector 52. The second branched laser beam LTB2 is reflected by the second optical member 22, focused by the second focusing lens 42, and enters the third end 32a of the second diffusion fiber 32. The second branched laser beam LTB2 that enters from the third end 32a passes through the second intermediate section 32c toward the fourth end 32b. A portion of the second branched laser beam LTB2 that enters from the third end 32a is emitted from the fourth end 32b. A portion of the second branched laser beam LTB2 that enters from the fourth end 32b passes through the third optical member 23 and enters the second photodetector 52. The laser beam LTy emitted from the second light source 10y is split into a third branched laser beam LTB3 and a fourth branched laser beam LTB4 in the third optical member 23. The third branched laser beam LTB3 is focused by the third focusing lens 43 and incident on the fourth end 32b of the second diffusion fiber 32. The third branched laser beam LTB3 incident from the fourth end 32b passes through the second intermediate section 32c and heads towards the third end 32a. A portion of the third branched laser beam LTB3 incident from the fourth end 32b is emitted from the third end 32a. A portion of the third branched laser beam LTB3 emitted from the third end 32a is reflected by the second optical member 22 toward the first optical member 21, and is further reflected by the first optical member 21 before being incident on the first photodetector 51. The fourth branched laser beam LTB4 is reflected by the fourth optical element 24, focused by the fourth focusing lens 44, and incident on the second end 31b of the first diffusion fiber 31.The fourth branched laser beam LTB4, incident from the second end 31b, passes through the first intermediate section 31c and heads toward the first end 31a. A portion of the fourth branched laser beam LTB4 incident from the second end 31b is emitted from the first end 31a. A portion of the fourth branched laser beam LTB4 emitted from the first end 31a passes through the first optical member 21 and is incident on the first light-receiving element 51.

[0110] (First and second photodetectors) The first light-receiving element 51 detects whether a portion of the third-branched laser beam LTB3 and a portion of the fourth-branched laser beam LTB4 are incident on it, and the intensity of the incident portion of the third-branched laser beam LTB3 and a portion of the fourth-branched laser beam LTB4. The second light-receiving element 52 detects whether a portion of the first-branched laser beam LTB1 and a portion of the second-branched laser beam LTB2 are incident on it, and the intensity of the incident portion of the first-branched laser beam LTB1 and a portion of the second-branched laser beam LTB2. The first light-receiving element 51 and the second light-receiving element 52 are, for example, photodiodes or phototransistors. The first light-receiving element 51 and the second light-receiving element 52 output the detection results to a control device (not shown). The control device controls the operation of the first light source 10x and the second light source 10y based on the detection results. For example, if there is no incident of a portion of the first-branched laser beam LTB1 and a portion of the second-branched laser beam LTB2 on the second light-receiving element 52, the control device stops the emission of laser beam LTx from the first light source 10x. For example, if the control device does not receive any of the third branch laser beam LTB3 and the fourth branch laser beam LTB4 from the first photodetector 51, it stops the emission of the laser beam LTy from the second light source 10y. For example, if the detection result of either the first photodetector 51 or the second photodetector 52 changes, the control device stops the emission of the laser beams LTx and LTy, as it is possible that laser light is leaking due to a break in the diffusion fiber.

[0111] In this way, the light-emitting device 600A can detect malfunctions by directing a portion of the first branched laser beam LTB1 and a portion of the second branched laser beam LTB2 into the second photodetector 52, and by directing a portion of the third branched laser beam LTB3 and a portion of the fourth branched laser beam LTB4 into the first photodetector 51. Furthermore, if there is a malfunction in the light-emitting device 600A, the safety of the light-emitting device 600A can be improved by stopping the emission of laser beam LTx from the first light source 10x and the emission of laser beam LTy from the second light source 10y.

[0112] (Second modified example of the sixth embodiment) Figure 16 is an explanatory diagram showing a light-emitting device according to a second modified example of the sixth embodiment. As shown in Figure 16, the light-emitting device 600B according to the second modification of the sixth embodiment is substantially the same as the light-emitting device 600, except that the first light source 10x and the second light source 10y are different.

[0113] In the light-emitting device 600B, the first peak wavelength of the first laser light LT1 emitted from the first light source section 11a of the first light source 10x is different from the fourth peak wavelength of the fourth laser light LT4 emitted from the fourth light source section 11d of the second light source 10y. The first light source 10x further includes a fifth dichroic mirror 13e. The fifth dichroic mirror 13e transmits the first laser light LT1 with the first peak wavelength and reflects the fourth laser light LT4 with the fourth peak wavelength. The second light source 10y further includes a sixth dichroic mirror 13f. The sixth dichroic mirror 13f transmits the fourth laser light LT4 with the fourth peak wavelength and reflects the first laser light LT1 with the first peak wavelength.

[0114] The irradiation of laser light LTx from the first light source 10x and laser light LTy from the second light source 10y is substantially the same as in the light-emitting device 600, so a description is omitted. In the light-emitting device 600B, the first laser light LT1 emitted from the first light source section 11a of the first light source 10x passes through the fifth dichroic mirror 13e before passing through the first dichroic mirror 13a. Also in the light-emitting device 600B, the fourth laser light LT4 emitted from the fourth light source section 11d of the second light source 10y passes through the sixth dichroic mirror 13f before passing through the third dichroic mirror 13c.

[0115] The laser beam LTx emitted from the first light source 10x is split in the first optical member 21 into a first branched laser beam LTB1 and a second branched laser beam LTB2. The first branched laser beam LTB1 is focused by the first focusing lens 41 and incident on the first end 31a of the first diffusion fiber 31. The first branched laser beam LTB1 incident from the first end 31a passes through the first intermediate section 31c and heads toward the second end 31b. A portion of the first branched laser beam LTB1 incident from the first end 31a is emitted from the second end 31b. A portion of the first branched laser beam LTB1 emitted from the second end 31b is reflected by the fourth optical member 24 and passes through the third optical member 23, heading toward the second light source 10y. The second branched laser beam LTB2 is reflected by the second optical element 22, focused by the second focusing lens 42, and incident on the third end 32a of the second diffusion fiber 32. The second branched laser beam LTB2 incident from the third end 32a passes through the second intermediate section 32c and heads toward the fourth end 32b. A portion of the second branched laser beam LTB2 incident from the third end 32a is emitted from the fourth end 32b. A portion of the second branched laser beam LTB2 emitted from the fourth end 32b is reflected by the third optical element 23 and heads toward the second light source 10y. The laser beam LTy emitted from the second light source 10y is branched in the third optical element 23 into the third branched laser beam LTB3 and the fourth branched laser beam LTB4. The third branched laser beam LTB3 is focused by the third focusing lens 43 and incident on the fourth end 32b of the second diffusion fiber 32. The third branched laser beam LTB3, incident from the fourth end 32b, passes through the second intermediate section 32c and heads toward the third end 32a. A portion of the third branched laser beam LTB3 incident from the fourth end 32b is emitted from the third end 32a. A portion of the third branched laser beam LTB3 emitted from the third end 32a is reflected by the second optical element 22 and passes through the first optical element 21, heading toward the first light source 10x. The fourth branched laser beam LTB4 is reflected by the fourth optical element 24, focused by the fourth focusing lens 44, and incident on the second end 31b of the first diffusion fiber 31. The fourth branched laser beam LTB4 incident from the second end 31b passes through the first intermediate section 31c and heads toward the first end 31a. A portion of the fourth branched laser beam LTB4 incident from the second end 31b is emitted from the first end 31a.A portion of the fourth branched laser beam LTB4 emitted from the first end 31a is reflected by the first optical member 21 and directed toward the first light source 10x. In this way, a portion of the first branched laser beam LTB1 and a portion of the second branched laser beam LTB2 may be directed toward the second light source 10y from the third optical member 23. Also, a portion of the third branched laser beam LTB3 and a portion of the fourth branched laser beam LTB4 may be directed toward the first light source 10x from the first optical member 21.

[0116] The fifth dichroic mirror 13e is positioned between the first light source unit 11a and the first optical element 21. More specifically, the fifth dichroic mirror 13e is positioned between the first light source unit 11a and the first dichroic mirror 13a. As described above, the fifth dichroic mirror 13e transmits the first laser light LT1 with a first peak wavelength and reflects the fourth laser light LT4 with a fourth peak wavelength. This allows the fourth laser light LT4 component with a fourth peak wavelength to be blocked from a portion of the third branched laser light LTB3 and a portion of the fourth branched laser light LTB4 that travel from the first optical element 21 to the first light source unit 11a. The first laser light LT1 with a first peak wavelength emitted from the first light source unit 11a is transmitted through the fifth dichroic mirror 13e.

[0117] The sixth dichroic mirror 13f is positioned between the fourth light source unit 11d and the third optical member 23. More specifically, the sixth dichroic mirror 13f is positioned between the fourth light source unit 11d and the third dichroic mirror 13c. As described above, the sixth dichroic mirror 13f transmits the fourth laser light LT4 with the fourth peak wavelength and reflects the first laser light LT1 with the first peak wavelength. This allows the first laser light LT1 component with the first peak wavelength to be blocked from a portion of the first branched laser light LTB1 and a portion of the second branched laser light LTB2 that travel from the third optical member 23 to the fourth light source unit 11d. The fourth laser light LT4 with the fourth peak wavelength irradiated from the fourth light source unit 11d is transmitted through the sixth dichroic mirror 13f.

[0118] Thus, by further providing a fifth dichroic mirror 13e positioned between the first light source unit 11a and the first optical element 21, the generation of COD caused by a portion of the third branched laser beam LTB3 and a portion of the fourth branched laser beam LTB4 reaching the first light source 10x can be reduced in the light-emitting device 600B. Furthermore, by further providing a sixth dichroic mirror 13f positioned between the fourth light source unit 11d and the third optical element 23, the generation of COD caused by a portion of the first branched laser beam LTB1 and a portion of the second branched laser beam LTB2 reaching the second light source 10y can be reduced. In particular, the effect is greater when the first laser beam LT1 and the fourth laser beam LT4 are red laser beams, as COD is more likely to occur in this case.

[0119] The first light source 10x may further include a seventh dichroic mirror that transmits the second laser beam LT2 and reflects the fifth laser beam LT5. The seventh dichroic mirror is, for example, positioned between the second light source unit 11b and the first optical member 21. More specifically, the seventh dichroic mirror is, for example, positioned between the second light source unit 11b and the first dichroic mirror 13a.

[0120] Furthermore, the second light source 10y may further include an eighth dichroic mirror that transmits the fifth laser beam LT5 and reflects the second laser beam LT2. The eighth dichroic mirror is, for example, positioned between the fifth light source unit 11e and the third optical member 23. More specifically, the eighth dichroic mirror is, for example, positioned between the fifth light source unit 11e and the third dichroic mirror 13c.

[0121] Furthermore, the first light source 10x may further include a ninth dichroic mirror that transmits the third laser beam LT3 and reflects the sixth laser beam LT6. The ninth dichroic mirror is positioned, for example, between the third light source unit 11c and the first optical member 21. More specifically, the ninth dichroic mirror is positioned, for example, between the second light source unit 11b and the second dichroic mirror 13b.

[0122] Furthermore, the second light source 10y may further include a tenth dichroic mirror that transmits the sixth laser beam LT6 and reflects the third laser beam LT3. The tenth dichroic mirror is, for example, positioned between the sixth light source unit 11f and the third optical member 23. More specifically, the tenth dichroic mirror is, for example, positioned between the sixth light source unit 11f and the fourth dichroic mirror 13d.

[0123] <Vehicle> Figure 17 is a perspective view showing a vehicle equipped with a light-emitting device according to an embodiment. Figure 18 is an explanatory diagram showing a tail lamp equipped with a light-emitting device according to an embodiment. As shown in Figure 17, the vehicle 900 according to this embodiment includes a vehicle body 910 and a light-emitting device 100.

[0124] The light-emitting device 100 is mounted on the vehicle body 910. In vehicle 900, the housing 80 of the light-emitting device 100 is located at the front of the vehicle body 910. The first diffusion fiber 31 and the second diffusion fiber 32 of the light-emitting device 100 are arranged from the housing 80 along the front and sides of the vehicle body 910.

[0125] As shown in Figure 18, the light-emitting device 100 may be attached to a taillight 911 located at the rear of the vehicle body 910. In the taillight 911, one first diffusion fiber 31 is arranged.

[0126] In this way, the design of the vehicle 900 can be improved by attaching the light-emitting device 100 to the body 910 and taillights 911.

[0127] Diffused fibers may be used for the applications described in UN R48 5.15 by illuminating them in the colors specified in UN R48 Regulation No. 48 of the Economic Commission for Europe of the United Nations 2.29-2.32. Alternatively, diffused fibers may be used as marker lamps for ADS (Automated Driving Systems) by illuminating them in the colors specified in SAE J3134 201905 6.2.1.

[0128] In addition, in each of the embodiments described above, the laser light transmitted by the dichroic mirror, optical element, polarizing multiplexer, polarizing element, etc., and the laser light reflected by them may be reversed.

[0129] The embodiment may include the following configurations.

[0130] (Composition 1) A light source that emits laser light, The laser beam is split into a first branched laser beam and a second branched laser beam, and a first optical member reflects the first branched laser beam and transmits the second branched laser beam. A first diffusion fiber having a first end into which at least a portion of the first branched laser beam reflected by the first optical member is incident, and a second end into which at least a portion of the second branched laser beam is incident, A light-emitting device. (Configuration 2) The invention further comprises a second optical member that reflects at least a portion of the second branched laser light, The light-emitting device according to claim 1, wherein the second branched laser light reflected by the second optical member is incident on the second end. (Composition 3) The light source comprises a first light source unit and a second light source unit. The light-emitting device according to configuration 1 or 2, wherein the light source irradiates the laser light obtained by combining a first laser beam emitted from the first light source unit and a second laser beam emitted from the second light source unit. (Composition 4) The first laser light has a first peak wavelength, The light-emitting device according to configuration 3, wherein the second laser light has a second peak wavelength different from the first peak wavelength. (Composition 5) The light source further includes a third light source unit that emits a third laser beam having a third peak wavelength different from the first peak wavelength and the second peak wavelength. The aforementioned first laser light is blue laser light, The aforementioned second laser light is green laser light, The aforementioned third laser light is red laser light, The light-emitting device according to configuration 4, wherein the light source irradiates the laser light obtained by wavelength-combining the red laser light, the green laser light, and the blue laser light. (Composition 6) It is further equipped with a light-receiving element, The second optical member splits the second branched laser beam into a third branched laser beam and a fourth branched laser beam, reflects the third branched laser beam, and transmits the fourth branched laser beam. The fourth branched laser beam is incident on the photodetector, and the light-emitting device is as described in any one of configurations 2 to 5. (Composition 7) It is further equipped with a light-receiving element, A light-emitting device according to any one of configurations 2 to 5, wherein a portion of the first branched laser light that is incident from the first end and emitted from the second end and reflected by the second optical member, and a portion of the second branched laser light that is incident from the second end and emitted from the first end and transmitted through the first optical member, are incident on the light-receiving element. (Composition 8) The light-emitting device according to any one of configurations 1 to 7, further comprising a polarizing member disposed between the light source and the first optical member. (Composition 9) The second optical member splits the second branched laser beam into a third branched laser beam and a fourth branched laser beam, reflects the third branched laser beam, and transmits the fourth branched laser beam. A third optical member that splits the fourth branched laser beam into a fifth branched laser beam and a sixth branched laser beam, reflects the fifth branched laser beam, and transmits the sixth branched laser beam, A fourth optical member that reflects at least a portion of the sixth branched laser beam, A second diffusion fiber having a third end into which the fifth branched laser beam reflected by the third optical member is incident, and a fourth end into which the sixth branched laser beam reflected by the fourth optical member is incident, A light-emitting device according to any one of configurations 2 to 8, further comprising the above. (Composition 10) The first light source unit comprises an S-polarized first light source unit that emits S-polarized blue laser light and a P-polarized first light source unit that emits P-polarized blue laser light. The second light source unit comprises an S-polarized second light source unit that emits S-polarized green laser light and a P-polarized second light source unit that emits P-polarized green laser light. The third light source unit comprises an S-polarized third light source unit that emits S-polarized red laser light and a P-polarized third light source unit that emits P-polarized red laser light. The light-emitting device according to configuration 5, wherein the light source irradiates laser light obtained by wavelength-combining red combined laser light obtained by polarization-combining S-polarized red laser light and P-polarized red laser light, green combined laser light obtained by polarization-combining S-polarized green laser light and P-polarized green laser light, and blue combined laser light obtained by polarization-combining S-polarized blue laser light and P-polarized blue laser light. (Composition 11) The first light source unit comprises a fourth light source unit, a fifth light source unit, and a first polarization multiplexing member, and polarizes and combines laser light emitted from the fourth light source unit and laser light emitted from the fifth light source unit before emitting the combined light. The second light source unit comprises a sixth light source unit, a seventh light source unit, and a second polarization multiplexing member, and polarizes and combines laser light emitted from the sixth light source unit and laser light emitted from the seventh light source unit before emitting the combined light. The light-emitting device according to configuration 3, wherein the light source irradiates the laser light obtained by wavelength combination of the laser light emitted from the first light source unit and the laser light emitted from the second light source unit. (Composition 12) The first light source unit comprises an S-polarized first light source unit that emits S-polarized blue laser light and a P-polarized first light source unit that emits P-polarized blue laser light. The second light source unit comprises an S-polarized second light source unit that emits S-polarized green laser light and a P-polarized second light source unit that emits P-polarized green laser light. The third light source unit comprises an S-polarized third light source unit that emits S-polarized red laser light and a P-polarized third light source unit that emits P-polarized red laser light. The light-emitting device according to configuration 5, wherein the light source irradiates the laser light obtained by polarizing and combining a first combined laser light obtained by wavelength combining the P-polarized red laser light, the P-polarized green laser light, and the P-polarized blue laser light, and a second combined laser light obtained by wavelength combining the S-polarized red laser light, the S-polarized green laser light, and the S-polarized blue laser light. (Composition 13) The light source further comprises a first polarization multiplexing member, The first light source unit comprises a fourth light source unit and a sixth light source unit, and combines the wavelengths of the laser light emitted from the fourth light source unit and the laser light emitted from the sixth light source unit and emits them toward the first polarization multiplexing member. The second light source unit comprises a fifth light source unit and a seventh light source unit, and combines the wavelengths of the laser light emitted from the fifth light source unit and the laser light emitted from the seventh light source unit and emits them toward the first polarization multiplexing member. The light-emitting device according to configuration 3, wherein the light source irradiates the laser light obtained by polarizing and combining the laser light emitted from the first light source unit and the laser light emitted from the second light source unit. (Composition 14) The first end has a first incident surface to which the first branched laser beam is incident, The second end has a second incident surface to which the second branched laser beam is incident, The light-emitting device according to any one of configurations 2 to 13, wherein the distance between the center of the first incident surface and the center of the second incident surface is 1 mm or more and 100 mm or less. (Composition 15) The first end has a first incident surface to which the first branched laser beam is incident, The second end has a second incident surface to which the second branched laser beam is incident, A light-emitting device according to any one of configurations 2 to 14, wherein the first incident surface and the second incident surface are arranged to face the same direction. (Composition 16) The car body and, A light-emitting device according to any one of configurations 1 to 15 attached to the vehicle body, A vehicle equipped with [a specific feature / equipment].

[0131] The embodiments described above are examples of the present invention, and the present invention is not limited to these embodiments. For example, the present invention is also included in the embodiments described above in which some components or processes are added, deleted, or modified. Furthermore, the embodiments described above can be implemented in combination with each other. [Explanation of Symbols]

[0132] 10:Light source 10x: 1st light source 10y: 2nd light source 11a: 1st light source section 11as:S polarization first light source section 11ap: P-polarized first light source section 11b:Second light source section 11bs:S polarized second light source section 11bp:P polarized second light source section 11c: Third light source section 11cs:S polarized third light source section 11cp:P polarized third light source section 11d: 4th light source section 11e: 5th light source section 11f: 6th light source section 12a: First collimating lens 12b: Second collimating lens 12c: Third collimating lens 13a: First dichroic mirror 13b: Second Dichroic Mirror 13c: Third Dichroic Mirror 13d: Fourth Dichroic Mirror 13e: Fifth Dichroic Mirror 13f: 6th Dichroic Mirror 14a: First polarization multiplexing member 14b: Second polarization multiplexing member 14c: Third polarization multiplexing member 21: First optical component 22: Second optical component 23: Third optical component 24: Fourth optical component 31: First Diffusion Fiber 31a: First end 31a1: 1st entrance plane 31b: Second end 31b1: Second entrance surface 31c: 1st intermediate part 32: Second Diffusion Fiber 32a: Third end 32a1: Third entrance plane 32b: 4th end 32b1: 4th entrance plane 32c: 2nd middle part 41: First condensing lens 42: Second focusing lens 43: Third focusing lens 44: Fourth condensing lens 50: Photodetector 51: First photodetector 52: Second photodetector 60: Polarizing material 80: Cabinet 100, 100A, 100B, 100C, 100D, 100E, 100F, 100G, 200, 300, 400, 500, 600, 600A, 600B: Light-emitting devices 900: Vehicle 910: Vehicle body 911: Taillights LCa: First-wavelength combined laser light LCb: Second-wave combined laser light LT, LTx, LTy: Laser light LT1: First laser beam LT1s: S-polarized first laser beam LT1p: P-polarized first laser beam LT2: Second laser beam LT2s: S-polarized second laser light LT2p: P-polarized second laser light LT3: Third laser beam LT3s: S-polarized third laser light LT3p: P-polarized third laser light LT4: Fourth laser beam LT5: Fifth laser beam LT6: 6th laser beam LTB1: First branched laser beam LTB2: Second branch laser beam LTB3: Third-branch laser beam LTB4: Fourth branch laser beam LTB5: Fifth branch laser beam LTB6: 6th branch laser beam

Claims

1. A light source that emits laser light, A first optical member that splits the laser light into a first branched laser beam and a second branched laser beam, reflects the first branched laser beam, and transmits the second branched laser beam, A first diffusion fiber having a first end into which at least a portion of the first branched laser beam reflected by the first optical member is incident, and a second end into which at least a portion of the second branched laser beam is incident, A light-emitting device.

2. The invention further comprises a second optical member that reflects at least a portion of the second branched laser light, The light-emitting device according to claim 1, wherein the second branched laser light reflected by the second optical member is incident on the second end.

3. The light source comprises a first light source unit and a second light source unit. The light-emitting device according to claim 1, wherein the light source irradiates the laser light obtained by combining the first laser light emitted from the first light source unit and the second laser light emitted from the second light source unit.

4. The first laser light has a first peak wavelength, The light-emitting device according to claim 3, wherein the second laser light has a second peak wavelength different from the first peak wavelength.

5. The light source further comprises a third light source unit that emits a third laser beam having a third peak wavelength different from the first peak wavelength and the second peak wavelength. The first laser light is a blue laser light, The aforementioned second laser light is green laser light, The third laser beam is a red laser beam. The light-emitting device according to claim 4, wherein the light source irradiates the laser light obtained by wavelength-combining the red laser light, the green laser light, and the blue laser light.

6. It is further equipped with a light-receiving element, The second optical member splits the second branched laser beam into a third branched laser beam and a fourth branched laser beam, reflects the third branched laser beam, and transmits the fourth branched laser beam. The light-emitting device according to claim 2, wherein the fourth branched laser beam is incident on the light-receiving element.

7. It is further equipped with a light-receiving element, The light-emitting device according to claim 2, wherein a portion of the first branched laser light that is incident from the first end and emitted from the second end and reflected by the second optical member, and a portion of the second branched laser light that is incident from the second end and emitted from the first end and transmitted through the first optical member, are incident on the light-receiving element.

8. The light-emitting device according to claim 1, further comprising a polarizing member disposed between the light source and the first optical member.

9. The second optical member splits the second branched laser beam into a third branched laser beam and a fourth branched laser beam, reflects the third branched laser beam, and transmits the fourth branched laser beam. A third optical member that splits the fourth branched laser beam into a fifth branched laser beam and a sixth branched laser beam, reflects the fifth branched laser beam, and transmits the sixth branched laser beam, A fourth optical member that reflects at least a portion of the sixth branched laser beam, A second diffusion fiber having a third end into which the fifth branched laser beam reflected by the third optical member is incident, and a fourth end into which the sixth branched laser beam reflected by the fourth optical member is incident, The light-emitting device according to claim 2, further comprising the above.

10. The first light source unit comprises an S-polarized first light source unit that emits S-polarized blue laser light and a P-polarized first light source unit that emits P-polarized blue laser light. The second light source unit comprises an S-polarized second light source unit that emits S-polarized green laser light and a P-polarized second light source unit that emits P-polarized green laser light. The third light source unit comprises an S-polarized third light source unit that emits S-polarized red laser light and a P-polarized third light source unit that emits P-polarized red laser light. The light-emitting device according to claim 5, wherein the light source irradiates laser light obtained by wavelength-combining red combined laser light obtained by polarization-combining S-polarized red laser light and P-polarized red laser light, green combined laser light obtained by polarization-combining S-polarized green laser light and P-polarized green laser light, and blue combined laser light obtained by polarization-combining S-polarized blue laser light and P-polarized blue laser light.

11. The first light source unit comprises a fourth light source unit, a fifth light source unit, and a first polarization multiplexing member, and polarizes and combines laser light emitted from the fourth light source unit and laser light emitted from the fifth light source unit before emitting the combined light. The second light source unit comprises a sixth light source unit, a seventh light source unit, and a second polarization multiplexing member, and polarizes and combines laser light emitted from the sixth light source unit and laser light emitted from the seventh light source unit before emitting the combined light. The light-emitting device according to claim 3, wherein the light source irradiates the laser light obtained by wavelength combination of the laser light emitted from the first light source unit and the laser light emitted from the second light source unit.

12. The first light source unit comprises an S-polarized first light source unit that emits S-polarized blue laser light and a P-polarized first light source unit that emits P-polarized blue laser light. The second light source unit comprises an S-polarized second light source unit that emits S-polarized green laser light and a P-polarized second light source unit that emits P-polarized green laser light. The third light source unit comprises an S-polarized third light source unit that emits S-polarized red laser light and a P-polarized third light source unit that emits P-polarized red laser light. The light-emitting device according to claim 5, wherein the light source irradiates the laser light obtained by polarizing and combining a first combined laser light obtained by wavelength combining the P-polarized red laser light, the P-polarized green laser light, and the P-polarized blue laser light, and a second combined laser light obtained by wavelength combining the S-polarized red laser light, the S-polarized green laser light, and the S-polarized blue laser light.

13. The light source further comprises a first polarization multiplexing member, The first light source unit comprises a fourth light source unit and a sixth light source unit, and combines the wavelengths of the laser light emitted from the fourth light source unit and the laser light emitted from the sixth light source unit and emits them toward the first polarization multiplexing member. The second light source unit comprises a fifth light source unit and a seventh light source unit, and combines the wavelengths of the laser light emitted from the fifth light source unit and the laser light emitted from the seventh light source unit and emits them toward the first polarization multiplexing member. The light-emitting device according to claim 3, wherein the light source irradiates the laser light obtained by polarizing and combining the laser light emitted from the first light source unit and the laser light emitted from the second light source unit.

14. The first end has a first incident surface to which the first branched laser beam is incident, The second end has a second incident surface to which the second branched laser beam is incident, The light-emitting device according to claim 2, wherein the distance between the center of the first incident surface and the center of the second incident surface is 1 mm or more and 100 mm or less.

15. The first end has a first incident surface to which the first branched laser beam is incident, The second end has a second incident surface to which the second branched laser beam is incident, The light-emitting device according to claim 2, wherein the first incident surface and the second incident surface are arranged to face the same direction.

16. The car body and, A light-emitting device according to any one of claims 1 to 15, which is attached to the vehicle body, A vehicle equipped with [a specific feature / equipment].

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