Lighting device

Abstract

Lighting device (1B) which subjects laser light, which is guided through an optical fiber (10), to a wavelength conversion so that it emits light with a wavelength different from that of the laser light, wherein the lighting device (1B) comprises: a holder (2b) that holds the optical fiber (10); a wavelength converter (3) that converts the laser light emitted by the optical fiber (10) into a wavelength converter; and a housing (4) that holds the wavelength transducer (3) and accommodates the holder (2b), wherein the holder (2b) comprises a first plate (91) and a second plate (92) arranged one above the other in such a way that they are in surface contact with each other, wherein the first plate (91) includes a groove (911) into which one end of the optical fiber (10) is fitted, wherein the second plate (92) is a pressure component that fixes one end of the optical fiber (10), where the groove (911) is straight.

Description

[Technical field]

[0001] The present invention relates to lighting devices to which an optical fiber is attached. [State of the art]

[0002] Conventionally, there are lighting devices that illuminate by causing a phosphor to emit light using laser light passed through an optical fiber as excitation light and converting the emitted light into light of a desired color (see, for example, Patent Document 1). In such lighting devices, positioning of one end of the optical fiber is typically performed by holding the end of the optical fiber with a sleeve.

[0003] DE 10 2012 109 088 A1 describes a fiber optic conversion module as part of a lighting device on a vehicle, which has at least one optical fiber provided with connectors, an output head and a converter mounted on a heat sink. [Document List][Patent Document]

[0004] [PTL 1] Japanese unexamined patent application with publication number JP 2014 - 10908 A [Summary of the invention][Technical problem]

[0005] However, since a ferrule is a comparatively expensive component, stable positioning of the end of an optical fiber without a ferrule is desirable.

[0006] In view of this, the present invention provides an illumination device that enables the positioning of an end of an optical fiber even without the use of a sleeve. [Solution to the problem]

[0007] The technical problem is solved by a lighting device having the features disclosed in claim 1. A further embodiment is defined in dependent claim 2. [Advantageous effects of the invention]

[0008] The present invention can provide an illumination device that enables the positioning of an end of an optical fiber even without the use of a sleeve. [Brief description of the drawings

[0009] Fig. Figures 1 to 6 and 9 show examples useful for understanding the invention. Fig. 7 and Fig. 8 show a lighting device according to the invention. Fig. 1 is an external perspective view of a structure of a lighting device according to an embodiment; Fig. Figure 2 is an exploded perspective view of the lighting device in the Fig. 1; Fig. 3 is a cross-sectional view of the lighting device in the Fig. 1; Fig. 4 is a cross-sectional view of a schematic structure of a holder according to the embodiment; Fig. 5 is a cross-sectional view of a schematic structure of a flange according to the embodiment; Fig. 6 is a cross-sectional view of a schematic structure of a holder according to a variation 1; Fig. 7 is a cross-sectional view of a lighting device according to a variation 2; Fig. Fig. 8 is a cross-sectional view of a schematic structure of a holder according to Variation 2; and Fig. 9 is a cross-sectional view of a lighting device according to Variation 3. [Description of embodiments]

[0010] Lighting devices according to embodiments of the present invention will be described below with reference to the drawings. It should be noted that each of the embodiments described below shows a specific example. Therefore, numerical values, shapes, materials, structural components, the arrangement and connection of the structural components, etc. shown in the following embodiments are merely examples and are not intended to limit the scope of the present invention. Furthermore, among the structural components in the following embodiments, components not specified in any of the independent claims, which specify the broadest concepts of the present invention, are described as arbitrary structural components.

[0011] Furthermore, the respective figures are schematic diagrams and not necessarily accurate representations. Furthermore, identical structural components are assigned the same reference numerals in the respective diagrams. [Embodiment]

[0012] Hereinafter, a lighting device 1 according to an embodiment of the present invention will be described with reference to the drawings.

[0013] First, the structure of a lighting device 1 is described. Fig. 1 is a perspective external view of the structure of the lighting device 1 according to this embodiment. Fig. Figure 2 is an exploded perspective view of the lighting device 1 in the Fig. 1. The Fig. 3 is a cross-sectional view of the lighting device 1 in the Fig. 1.

[0014] As it is in the Fig. 1 to Fig. 3, the illumination device 1 comprises a holder 2, a wavelength converter 3, a housing 4, a lens 5 and a lens holder 6. [Holder]

[0015] The holder 2 is a component that holds optical fibers 10. Specifically, the holder 2 includes a first component 21 and a second component 22, and the optical fibers 10 are held when the first component 21 and the second component 22 are in an attached state. In this embodiment, a pair of optical fibers 10 arranged side by side in a radial direction are held in the holder 2 in a state where the optical fibers 10 are accommodated within a protective tube 11. It should be noted that the number of optical fibers 10 held together by the holder 2 may be one or three or more. Further, laser light beams emitted by a light emitter (e.g., a semiconductor laser diode that emits light with a short wavelength of at least 500 nm) not shown in the figures enter from base end faces of the pair of optical fibers 10.The laser light beams guided through the optical fibers 10 are emitted from front end surfaces (light emission surfaces) of the optical fibers 10.

[0016] The Fig. Fig. 4 is a cross-sectional view of a schematic structure of the holder 2 according to this embodiment. In particular, Fig. 4 a cross-sectional view of the holder 2 along the line IV-IV in the Fig. 3. In the Fig. 4, the illustration of the housing 4 is omitted. [First component]

[0017] As it is in the Fig. 3 and the Fig. 4, the first component 21 is a component made of a metal or resin, and includes a main body 211 and a flange 212. The main body 211 is formed into a shape obtained by cutting a front end portion of a columnar component into a half-column shape. A linear groove 213 extending along the axial direction of the main body 211 is formed in a flat portion of the half-column portion of the main body 211. Further, a pair of screw holes 214 extending in a direction orthogonal to the flat portion are formed in the flat portion of the half-column portion of the main body 211. Further, a linear holding hole 215 communicating with the groove 213 is formed in the main body 211. Optical fibers 10 are arranged within the holding hole 215 and the groove 213.The front ends (one ends) of the pair of optical fibers 10, arranged side by side in a radial direction, are fitted together into the groove 213. The light-emitting surfaces (front end surfaces) of the optical fibers 10 are flush with the front end surface of the main body 211. Specifically, the laser light beams are emitted through the optical fibers 10 from the front end surface of the main body 211.

[0018] Furthermore, the optical fibers 10 are arranged together with the protective tube 11 within the holding hole 215. A screw hole 216 extending along the radial direction of the main body 211 is formed in the main body 211 so as to communicate with the holding hole 215. By screwing the set screw 217 into the screw hole 216 so that the protective tube 11 is fixed by the set screw 217, the pair of optical fibers 10 and the protective tube 11 can be secured within the holding hole 215.

[0019] The flange 212 protrudes from the outer peripheral surface of the base end of the main body 211 and extends continuously over the entire circumference. It should be noted that the flange 212 may protrude discontinuously from the outer peripheral surface of the base end of the main body 211 and may be provided only in a portion of the outer peripheral surface of the base end of the main body 211. Furthermore, a pair of mounting holes 250 are formed in the flange 212 at opposite positions parallel to the axial direction above the main body 211. The mounting holes 250 are holes for attaching the housing 4 to the first component 21 by means of first screws 260.Specifically, each of the mounting holes 250 includes a first shaft hole 253 located on the front end side of the flange 212, into which the shaft 261 of the first screw 260 is inserted, and a first counterbore 254 located on the base end side of the flange 212 to communicate with the first shaft hole 253, and within which the head 262 of the first screw 260 is received. The first counterbores 254 are formed in the shape of circles with larger diameters than those of the first shaft holes 253.

[0020] The Fig. 5 is a cross-sectional view of a schematic structure of the flange 212 according to this embodiment. In particular, the Fig. 5 is a cross-sectional view of the flange 212 taken along line 4-4 in the Fig. 4.

[0021] As it is in the Fig. 4 and the Fig. 5, a pair of fastening holes 270 parallel to the axial direction are provided in the flange 212 at adjacent positions different from the positions of the fastening holes 250. The fastening holes 270 are holes for attaching the holder 2 to the bracket 90 for supporting the lighting device 1 by means of second screws 280. Specifically, each of the fastening holes 270 includes a second shaft hole 273 located on the base end side of the flange 212 and into which the shaft 281 of the second screw 280 is inserted, and a second counterbore 274 located on the front end side of the flange 212 for connecting to the second shaft hole 273 and within which the head 282 of the second screw 280 is received. The second counterbores 274 are formed in the shape of circles with larger diameters than the second shaft holes 273.

[0022] On the other hand, screw holes 99 corresponding to respective mounting holes 270 are formed in the bracket 90. When the screw holes 99 and the mounting holes 270 of the first component 21 are aligned, and the second screws 280 are inserted into the mounting holes 270 and screwed into the screw holes 99, the first component 21 is attached to the bracket 90. [Second component]

[0023] As it is in the Fig. 3 and the Fig. As shown in Figure 4, the second component 22 is a component formed in a semi-column shape. A pair of fastening holes 221 are formed in the second component 22, penetrating from the outer peripheral surface to the flat portion. The fastening holes 221 extend in a direction orthogonal to the flat portion and communicate with the screw holes 214 of the first component 21 when the second component 22 is attached to the first component 21. In other words, the fastening holes 221 are holes for fastening the second component 22 to the first component 21 using third screws 290.Specifically, each of the fastening holes 221 includes a third shaft hole 222 located on the flat portion side of the second component 22 and into which the shaft 291 of the third screw 290 is inserted, and a third counterbore 223 located on the outer peripheral surface side of the second component 22 for connecting to the third shaft hole 222 and within which the head 292 of the third screw 290 is received. The third counterbores 223 are formed in the shape of circles with larger diameters than the third shaft holes 222. Then, when the second component 22 is attached to the first component 21, the flat portions of the second component 22 and the first component 21 are superimposed, and third screws 290 are inserted into the fastening holes 221 and screwed into the screw holes 214.As a result, the second component 22 is attached to the first component 21, and the second component 22 and the first component 21 form a columnar portion. Furthermore, the heads 292 of the third screws 290 are received within the corresponding third counterbores 223. At this time, the front ends of the optical fibers 10, which are fitted into the groove 213 of the first component 21, are fixed by the second component 22. In other words, the second component 22 is a pressing component that fixes the front ends of the optical fibers 10. In this way, displacement of the front ends of the optical fibers 10 from the groove 213 is prevented because the front ends of the optical fibers 10 are fixed by the second component 22. [Wavelength converter]

[0024] As it is in the Fig. 2 and the Fig. As shown in Figure 3, the wavelength converter 3 is mounted in the housing 4 such that it is positioned opposite the light-emitting surfaces of the optical fibers 10. The wavelength converter 3 is an optical element that converts the wavelength of the laser light beams emitted from the light-emitting surfaces of the optical fibers 10 into another wavelength, thereby emitting light of a different color. The wavelength converter 3 includes a substrate 31 and a fluorescent portion 32.

[0025] The substrate 31 supports the fluorescent portion 32 and is, for example, an annular substrate. A plurality of insertion holes 34 for attaching the substrate 31 to the housing 4 by means of screws 33 are formed in the periphery of the substrate 31 at predetermined intervals in the circumferential direction.

[0026] The fluorescent portion 32 is attached to the substrate 31 so as to cover the hole in the center of the substrate 31. The fluorescent portion 32 comprises, for example, particles of a phosphor in a dispersed state that emit fluorescence when excited with laser light, and the phosphor emits fluorescence when irradiated with laser light. Specifically, an example of the fluorescent portion 32 is a component in which phosphor particles are dispersed within a base material comprising a transparent resin or glass, or a component in which phosphor particles are densely packed, etc.

[0027] In this embodiment, the fluorescent portion 32 emits white light and includes two types of phosphors in an appropriate ratio: a red phosphor that emits red light and a yellow phosphor that emits yellow light when irradiated with laser light. Furthermore, the fluorescent portion 32 may include three types of phosphors: a red phosphor that emits red light, a blue phosphor that emits blue light, and a green phosphor that emits green light when irradiated with laser light.

[0028] Although there is no specific limitation on the type or properties of the phosphors, it is preferable that the phosphors have high heat resistance because laser light with a relatively high output serves as the excitation light. Although there is no specific limitation on the type of base material that keeps the phosphor in a dispersed state, it is further preferable to use a base material with higher transparency because this also improves the white light emission efficiency. Furthermore, since laser light with a relatively high output enters, a base material with high heat resistance is preferred. [Housing]

[0029] The housing 4 is a housing made of a metal with very good heat dissipation properties, such as an Fe-based alloy (SUS, SF material, etc.) or a Cu-based alloy (brass, etc.). As shown in the Fig. 3, the housing 4 is formed in a substantially cylindrical (i.e., round) shape, and an external thread 410 for fixing the lens holder 6 is formed on the outer peripheral surface of the front end portion of the housing 4. Further, a plurality of screw holes 42 for fixing the wavelength converter 3 are formed in the front end surface of the housing 4. By placing the wavelength converter 3 on the front end surface of the housing 4 and aligning the insertion holes 34 of the wavelength converter 3 and the screw holes 42 of the housing 4, and then screwing the screws 33 into the screw holes 42 through the insertion holes 34, the wavelength converter 3 is fixed to the front end surface of the housing 4. By this fixing, the substrate 31 and the fluorescent portion 32 of the wavelength converter 3 are connected to the housing 4.Thereby, the heat generated in the fluorescent section 32 is directly transferred to the housing 4 and transferred to the housing 4 via the substrate 31 and is dissipated from the housing 4 to the outside.

[0030] The holder 2 is housed inside the housing 4. Specifically, the through-hole 41 is formed at the center of the front end surface of the housing 4 along the axial direction. The through-hole 41 extends from the front end surface to the base end surface of the housing 4. The holder 2 is housed inside the through-hole 41. The wavelength converter 3 is arranged coaxially with the through-hole 41. Although the case where the wavelength converter 3 covers the through-hole 41 from the outside of the through-hole 41 is exemplified in this embodiment, it should be noted that it is sufficient that the wavelength converter 3 is arranged coaxially with the through-hole 41. In other words, the wavelength converter 3 does not need to cover the through-hole 41 and can be arranged inside the through-hole 41.

[0031] The through-hole 41 is formed in a shape having an inner circumference that decreases in steps (monotonous decrease) from the base end surface (first end surface) to the front end surface (second end surface) of the housing 4. Specifically, the through-hole 41 sequentially includes, from the front end side, a small-diameter portion 411, a medium-diameter portion 412, and a large-diameter portion 413. The small-diameter portion 411, the medium-diameter portion 412, and the large-diameter portion 413 are coaxially arranged columnar holes.

[0032] The small-diameter portion 411 serves as an optical path that guides the laser light beams emitted from the optical fibers 10 upward to the fluorescence portion 32 of the wavelength converter 3. In other words, the light-emitting surfaces of the optical fibers 10 held in the holder 2 are located opposite the fluorescence portion 32 of the wavelength converter 3 via the small-diameter portion 411.

[0033] The holder 2 is housed in the medium-diameter section 412 and the large-diameter section 413. Specifically, the main body 211 of the first component 21 of the holder 2 and the second component 22 are housed in the medium-diameter section 412, and the flange 212 of the first component 21 is housed in the large-diameter section 413.

[0034] The intermediate diameter portion 412 is a first portion into which the main body 211 of the holder 2 is fitted together with the second component 22. Specifically, the inner diameter of the intermediate diameter portion 412 is formed to a size suitable for fitting the columnar portion formed by attaching the main body 211 of the first portion 21 and the second component 22. This fitting determines the position of the holder 2 in the direction orthogonal to the axial direction and consequently also determines the position of the optical fibers 10 held in the holder 2 in the direction orthogonal to the axial direction.

[0035] Furthermore, a lower surface of the front end side of the intermediate diameter portion 412 abuts against the surface 45 against which each of the front end surface of the first component 21 and the front end surface of the second component 22 of the holder 2 abuts. By abutting the front end surface of the first component 21 and the front end surface of the second component 22 against the surface 45, the positioning of the light-emitting surfaces of the optical fibers 10 held in the holder 2 can be performed. The distance between the abutting surface 45 and the fluorescent portion 32 is set to a length that enables appropriate positioning of the light-emitting surfaces of the optical fibers 10 held in the holder 2 with respect to the fluorescent portion 32.

[0036] The large-diameter portion 413 is a second portion located further on the base end side than the medium-diameter portion 412, and is formed in a shape for receiving the flange 212. Since the entirety of the holder 2 fits into the housing 4 when the flange 212 is received within the large-diameter portion 413, a good appearance can be obtained.

[0037] Furthermore, a plurality of first screw holes 46, with which respective fastening holes 250 of the flange 212 are aligned in a straight line, are formed in the lower surface on the front end side of the large-diameter portion 413. When the shanks 261 of the first screws 260 are screwed into the first screw holes 46 via the fastening holes 250 of the flange 212 received in the large-diameter portion 413, the holder 2 is fastened to the housing 4. Since the heads 262 of the first screws 260 are received in the first countersunk holes 254 of the fastening holes 250 after fastening, the entire first screws 260 fit into the housing 4, and deterioration of the aesthetic appearance of the lighting device 1 as a whole is prevented. [Lens]

[0038] As it is in the Fig. 3, the lens 5 is a light distribution adjusting lens that adjusts the light distribution of light resulting from wavelength conversion by the fluorescent portion 32 of the wavelength converter 3. The opposite surface of the lens 5, which faces the fluorescent portion 32, is shaped to absorb as much of the light emitted from the fluorescent portion 32 as possible without leakage. The shape of the opposite surface of the lens 5 is optimized under the premise that the positional relationship (i.e., the gap) between the lens 5 and the fluorescent portion 32 is constant. A protrusion 51 is formed around the entire circumference of the outer peripheral surface of the front end of the lens 5, and engagement of the protrusion 51 with the lens holder 6 causes the lens 5 to be held by the lens holder 6. [Lens holder]

[0039] As it is in the Fig. 3, the lens holder 6 is a part that holds the lens 5, and includes the outer body 61 and the holding member 62. The outer body 61 is a substantially cylindrical component formed of a metal or resin, and inside which the lens 5 and the holding member 62 are housed. An internal thread 63, into which the external thread 410 of the housing 4 is screwed, is formed in the inner peripheral surface of the base end of the outer body 61. Further, a protrusion 64, which protrudes inward, is formed around the entire circumference of the inner peripheral surface of the front end of the outer body 61. The protrusion 64 abuts against the protrusion 51 of the lens 5.

[0040] The holding member 62 is a substantially cylindrical component formed of metal or resin, within which the lens 5 is housed. The front end of the holding member 62 abuts against the protrusion 51 of the lens 5. Specifically, when the outer body 61 is screwed onto the housing 4 in the state where the lens 5 and the holding member 62 are housed within the outer body 61, the protrusion 51 of the lens 5 is held between the front end of the holding member 62 and the protrusion 64 of the outer body 61. Accordingly, the positioning of the lens 5 is performed.

[0041] Next, the method of assembling the lighting device 1 will be described.

[0042] Based on the Fig. In the state shown in Figure 2, the wavelength converter 3 is attached to the housing 4 by means of the screws 33. Subsequently, the lens 5 and the lens holder 6 are attached to the housing 4. Specifically, the internal thread 63 of the outer body 61, in which the lens 5 and the holding element 62 are received, are screwed to the external thread 410 of the housing 4, so that the lens 5 and the lens holder 6 are attached to the housing 4.

[0043] On the other hand, the pair of optical fibers 10 are attached to the first component 21 of the holder 2 via the protective tube 11. Specifically, the pair of optical fibers 10 and the protective tube 11 are inserted into the holding hole 215 of the first component 21. At this time, the front ends of the pair of optical fibers 10 are pulled out of the protective tube 11 and fitted into the groove 213 of the first component 21. Next, by screwing the grub screw 217 into the screw hole 216 of the first component 21, the pair of optical fibers 10 and the protective tube 11 are fixed within the holding hole 215.

[0044] Subsequently, the second component 22 is attached to the first component 21. In particular, as shown in the Fig. 4, the respective flat portions of the second component 22 and the first component 21 are superimposed, and third screws 290 are inserted into the mounting holes 221 and screwed into the screw holes 214. This attaches the second component 22 to the first component 21, and the second component 22 and the first component 21 form a columnar portion. At this time, the heads 292 of the third screws 290 are received within the third counterbores 223 and do not protrude from the second component 22.

[0045] In this case, before the holder 2 is attached to the housing 4, the first component 21 of the holder 2 is attached to the support 90 for supporting the lighting device 1. In particular, as shown in the Fig. As shown in Figure 5, when the screw holes 99 of the support 90 and the mounting holes 270 of the first component 21 are aligned, and the second screws 280 are inserted into the mounting holes 270 and screwed into the screw holes 99, the first component 21 is attached to the support 90. After attachment, the heads 282 of the second screws 280 are received within the second countersinks 274 and do not protrude from the first component 21.

[0046] Next, as stated in the Fig. 3, the holder 2 is attached to the housing 4. Specifically, the holder 2 is inserted and fitted into the intermediate diameter portion 412 of the through-hole 41 of the housing 4. This fitting determines the position of the holder 2 in the direction orthogonal to the axial direction. Furthermore, since the front end surface of the holder 2 abuts against the surface 45 of the housing 4 after the above-mentioned insertion, the axial direction position of the holder 2 is determined. Accordingly, the positions of the light-emitting surfaces of the optical fibers 10 in the holder 2 in the axial direction and the direction crossing the axial direction are determined.

[0047] Subsequently, the holder 2 is fastened to the housing 4. In particular, when the fastening holes 250 of the first component 21 and the first screw holes 46 of the housing 4 are aligned and the first screws 260 are inserted into the fastening holes 250 and screwed into the first screw holes 46, the holder 2 is fastened to the housing 4. After fastening, the heads 262 of the first screws 260 are received within the first countersinks 254 and do not protrude from the first component 21. After assembly, the lighting device 1 has the Fig. 1 and the Fig. 3 shown condition.

[0048] As described above, the illumination device 1 according to this embodiment is an illumination device that wavelength-converts laser light transmitted through the optical fibers 10 to output light having a different wavelength from the laser light. The illumination device 1 includes the holder 2 that holds the optical fibers 10, the wavelength converter 3 that converts the wavelength of the laser light emitted from the optical fibers 10, and the housing 4 that holds the wavelength converter 3 and houses the holder 2. The holder 2 includes the groove 213, which is straight and into which the front ends of the optical fibers 10 are fitted.

[0049] Accordingly, fitting the optical fibers 10 into the groove 213 makes it possible to perform the positioning of the front ends of the optical fibers 10, since the linear groove 213 into which the front ends of the optical fibers 10 are fitted is formed in the holder 2. In other words, positioning of the front ends of the optical fibers 10 becomes possible even without using a ferrule.

[0050] Furthermore, the holder 2 comprises the second portion 22 (pressing portion) which fixes the front ends of the optical fibers 10 fitted into the groove 213.

[0051] Since the front ends of the optical fibers 10 are fixed by the second component 22, displacement of the front ends of the optical fibers 10 from the groove 213 can be prevented. Therefore, the stability of the positioning of the optical fibers 10 can be improved.

[0052] Furthermore, the plurality of optical fibers 10 arranged side by side in a radial direction are fitted together into the groove 213.

[0053] Furthermore, since a plurality of optical fibers 10 are fitted together into the one groove 213, the labor during manufacture can be reduced compared with the case where one groove 213 is formed for each optical fiber 10. (Variation 1)

[0054] In the above embodiment, the case where the groove 213 into which the optical fibers 10 are fitted is formed only in the first component 21 is exemplified. In Variation 1, the case where the groove 223a is also formed in the second component 22a is exemplified.

[0055] It should be noted that in the following description, the same reference numerals are assigned to components identical to those in the above embodiment, and there are cases where the description thereof is omitted.

[0056] The Fig. Fig. 6 is a cross-sectional view of a schematic structure of the holder 2a according to the variation 1. In particular, the Fig. 6 a diagram showing the Fig. 4 corresponds.

[0057] As it is in the Fig. As shown in Figure 6, the groove 213a of the first component 21a of the holder 2a is formed in a shape for receiving housing portions (in this variation, the lower halves) of the pair of optical fibers 10. The groove 223a is received in the second component 22a at a location opposite the groove 213a of the first component 21a. The groove 223a is formed in a shape for receiving the portions (in this embodiment, the upper halves) of the pair of optical fibers 10 that protrude from the groove 213a. The pair of optical fibers 10 are fitted within the grooves 213a and 223a. In this case, too, the optical fibers 10 can be fixed by means of the second component 22a. (Variation 2)

[0058] In the above embodiment, the case where the optical fibers 100 are held by the first component 21 and the second component 22 is exemplified. In Variation 2, the case where the optical fibers 100 are held by a pair of plates 91 and 92, which are separate components from the first component 21b, is described.

[0059] The Fig. Fig. 7 is a cross-sectional view of the lighting device 1B according to Variation 2. In particular, the Fig. 7 a diagram showing the Fig. 3. The Fig. Fig. 8 is a cross-sectional view of a schematic structure of the holder 2b according to the variation 2. In particular, the Fig. 8 a cross-sectional view of the holder 2 along the line VIII-VIII in the Fig. 7 and it is a diagram that the Fig. 4 corresponds.

[0060] As it is in the Fig. 7 and the Fig. As shown in Fig. 8, the holder 2b includes the first component 21b and the pair of plates 91 and 92. The recess 214b, which is cut out along the axial direction from the front end surface of the first component 21b, is formed in the main body 211b of the first component 21b. The pair of plates 91 and 92 are arranged within the recess 214b. A substantially semi-columnar first portion 216b and a columnar second portion 217b, which opposes the first component 216b with the recess 214b arranged therebetween, are provided in the main body 211b. A pair of screw holes 218b for fixing the pair of plates 91 and 92 are formed in the flat portion of the first portion 216b. Further, the pair of plates 91 and 92 are stacked on the flat portion of the first portion 216b.

[0061] The plate 91 is a rectangular plate disposed on the flat portion of the first section 216b, and a linear groove 911 is formed on a main surface of the plate 91. When the plate 91 is disposed at a predetermined position on the flat portion of the first section 216b, the groove 911 is aligned in a straight line with the support hole 215. The front ends of the pair of optical fibers 10 are fitted together within the groove 911. Furthermore, a pair of insertion holes 912 are formed in the plate 91, which are connected to the pair of screw holes 218b.

[0062] The plate 92 is a rectangular plate arranged on top of the main surface of the plate 91. The plate 92 is a pressing component that fixes the front ends of the pair of optical fibers 10 fitted into the groove 911. A pair of fixing holes 920 are formed in the plate 92, corresponding to the insertion holes 912 of the plate 91. The fixing holes 920 are holes for fixing the plates 91 and 92 to the first portion 216b by means of the screws 295. Specifically, each of the fixing holes 920 includes the shaft hole 921 into which the shaft 296 of the screw 295 is inserted, and the counterbore 922 connected to the shaft hole 921 and within which the head 297 of the screw 295 is received.When the screws 295 are inserted into the mounting holes 920 of the plate 92 and the mounting holes 912 of the plate 91 and screwed into the screw holes 218b of the first section 216b, the pair of plates 91 and 92 are attached to the first section 216b. Then, as shown in the . Fig. 7, front end surfaces of the pair of plates 91 and 92 abut against the surface 45 of the housing 4, thereby enabling the positioning of the optical fibers 10 within the groove 911 of the plate 91. Furthermore, since the optical fibers 10 are held by the plates 91 and 92, which are separate components from the first component 21b, the optical fibers 10 can be attached to the first component 21b after first being fitted into the plate 91 at a position different from that of the first component 21b. Therefore, the degree of freedom of the fitting work for the optical fibers 10 can be increased. (Variation 3)

[0063] In the above embodiment, the case where the flange 212 of the holder 2 is accommodated within the housing 4 is exemplified. In Variation 3, the case where the flange 212 is not accommodated within the housing 4 is exemplified.

[0064] The Fig. 9 is a cross-sectional view of the lighting device 1C according to Variation 3. In particular, the Fig. 9 a diagram showing the Fig. 3 corresponds.

[0065] As it is in the Fig.As shown in Fig. 9, the through hole 41c, which does not have the large-diameter portion 413, is formed in the housing 4c of the lighting device 1C. As such, the first screw holes 46 are formed in the base end surface of the housing 4c. Accordingly, the flange 212 of the holder 2 is attached to the base end surface of the housing 4c and protrudes from the housing 4c. It should be noted that it is acceptable for only a part of the flange 212 to be housed in the housing 4c. (Miscellaneous)

[0066] Although lighting devices according to the present invention have been described so far based on the above embodiment and variations thereof, the present invention is not limited to the above embodiment and variations thereof.

[0067] For example, in the above embodiment, the housing 4 is exemplified as having a substantially cylindrical shape, but it may have any shape as long as it is tubular. As another shape for the housing 4, a substantially square tubular shape may be provided. Furthermore, the holder 2 may also have any shape as long as it is a shape that can be accommodated within the through-hole 41 of the housing 4.

[0068] Furthermore, in the above embodiment, the case where a plurality of optical fibers 10 are fitted into one groove 213 is exemplified. However, a plurality of grooves may be formed in the holder, and an optical fiber may be fitted into each of the grooves.

[0069] Furthermore, in the above embodiment, the case where the flange 212 of the holder 2 is fixed to the housing 4 by means of screws is exemplified. However, the method of fixing the flange 212 to the housing 4 may be any method. Other fixing methods may include fixing by mutual fitting or fixing with adhesives, etc. It should be noted that if the flange 212 of the holder 2 is detachably fixed to the housing 4, workability during maintenance can be improved.

[0070] Forms that can be obtained by various modifications of the embodiments that can be devised by a person skilled in the art, as well as forms that are realized by arbitrarily combining structural components and functions in the embodiment included in the scope of the gist of the present invention, are included in the present invention. [List of reference symbols] 1, 1B, 1C, 1D Lighting device 2, 2a, 2b, 2d holder 3 wavelength converters 4, 4c housing 10 optical fibers 22, 22a Second component (pressure component) 91 plate (first plate) 92 plate (second plate) 213, 213a, 223a, 911 groove

Claims

[1] An illumination device (1B) which wavelength-converts laser light guided through an optical fiber (10) to emit light having a wavelength different from that of the laser light, the illumination device (1B) comprising: a holder (2b) holding the optical fiber (10); a wavelength converter (3) which subjects the laser light emitted by the optical fiber (10) to a wavelength conversion; and a housing (4) which holds the wavelength converter (3) and accommodates the holder (2b), wherein the holder (2b) comprises a first plate (91) and a second plate (92) arranged one above the other so that they are in surface contact with each other, wherein the first plate (91) comprises a groove (911) into which one end of the optical fiber (10) is fitted, wherein the second plate (92) is a pressing component that fixes one end of the optical fiber (10), where the groove (911) is straight. [2] The lighting device (1B) according to claim 1, wherein the optical fiber (10) comprises a plurality of optical fibers (10) arranged side by side in a radial direction and fitted together into the groove (911).

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