Fiber Optic Illumination Device

Abstract

Provided is an optical fiber lighting device that uses an optical fiber that is not manufactured using a special method to improve the amount of light emitted from the side. The optical fiber lighting device (1) comprises: an optical fiber bundle (10) having a first end and a second end that are polished, a plurality of optical fibers, and a resin jacket (101) that covers the bundled plurality of optical fibers to emit light; and a first light source that is disposed close to the first end so as to emit light in an angle range larger than the aperture angle of the plurality of optical fibers to the optical fiber bundle.

Description

[0001] Cross-references of related applications

[0002] This application claims the priority of patent application No. 2019-218977 filed in Japan on December 3, 2019, and the disclosure of the prior application is incorporated herein in its entirety for reference. Technical Field

[0003] The present disclosure relates to fiber optic lighting devices. Background Art

[0004] In the past, there is known an optical fiber lighting device that uses the side of the optical fiber to emit light for lighting. The optical fiber used in the lighting device allows light incident from at least one end of the core in the longitudinal direction to pass through the cladding and leak light. For example, the optical fiber described in Patent Document 1 has a plurality of nano-sized structures inside the core or at the boundary between the core and the cladding to scatter light more evenly.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2019-153590 Summary of the invention

[0008] Problems to be solved by the invention

[0009] However, it is difficult to appropriately disperse particles in an optical fiber including particles that scatter light like a nano-sized structure, and the manufacturing is difficult. That is, the optical fiber described in Patent Document 1 is manufactured using a special method.

[0010] In view of this, an object of the present disclosure is to provide a fiber optic lighting device that uses an optical fiber that is not manufactured using a special method and improves the amount of light emitted from the side.

[0011] Means for solving problems

[0012] An optical fiber lighting device according to one embodiment of the present disclosure comprises: an optical fiber bundle having a polished first end and a polished second end, and having a plurality of optical fibers and a resin jacket covering the bundled plurality of optical fibers to emit light; and a first light source arranged close to the first end so as to emit light in an angle range larger than the aperture angle of the plurality of optical fibers to the optical fiber bundle.

[0013] Effects of the Invention

[0014] According to one embodiment of the present disclosure, it is possible to provide an optical fiber illumination device that uses an optical fiber that is manufactured without using any special method and that improves the amount of light emitted from the side. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1It is a figure which shows the external appearance of the optical fiber illumination device which concerns on one embodiment.

[0016] Figure 2 yes Figure 1 A partial cross-sectional view of a fiber optic lighting device.

[0017] Figure 3 yes Figure 2 An enlarged view of cross-sectional area A.

[0018] Figure 4 is a cross-sectional view of a fiber optic bundle.

[0019] Figure 5 It is a diagram illustrating the distance between the light source and the end of the optical fiber bundle and the incident angle.

[0020] Figure 6 It is a diagram showing the relationship between the distance between the light source and the end of the optical fiber bundle and the ratio of the light amount.

[0021] Figure 7 This is a diagram showing changes in the amount of side light emission due to differences in the incident angle of light.

[0022] Figure 8 This is a diagram showing changes in the amount of side light emission due to differences in the numerical aperture of the optical fiber.

[0023] Fig. 9 It is a diagram showing the relationship between the numerical aperture of an optical fiber and the ratio of the light amount.

[0024] Fig.10 It is a diagram showing the appearance of an optical fiber illumination device according to a modified example.

[0025] Fig.11 It is a diagram showing the appearance of an optical fiber illumination device according to another modified example.

[0026] Fig.12 It is a diagram for explaining the distance d, the distance L, and the distance h. DETAILED DESCRIPTION

[0027] Figure 11 is a diagram showing the appearance of an optical fiber illumination device 1 according to an embodiment. The optical fiber illumination device 1 has an optical fiber bundle 10 covered with a resin jacket 101, a first light incident portion 20-1, and a second light incident portion 20-2. The resin jacket 101 corresponds to the side of the optical fiber bundle 10 and is a portion that emits light. The optical fiber bundle 10 has a first end and a second end on the opposite side of the first end in the length direction. The first end and the second end are polished. The first end and the second end are, for example, flat surfaces formed as optical polished surfaces. The first light incident portion 20-1 and the second light incident portion 20-2 respectively inject light into the first end and the second end of the optical fiber bundle 10. The incident light leaks out from the inside of the optical fiber bundle 10 and is diffused by the resin jacket 101, so that the side of the optical fiber illumination device 1 emits light. The optical fiber illumination device 1 of this embodiment has a first light incident portion 20-1 and a second light incident portion 20-2. However, the optical fiber illumination device 1 may also be a structure that has only one of the first light incident portion 20-1 and the second light incident portion 20-2. In addition, in the present embodiment, the first light incident portion 20-1 has the same structure as the second light incident portion 20-2. However, the first light incident portion 20-1 may have a different structure from the second light incident portion 20-2.

[0028] Figure 2 : is a partial cross-sectional view of the optical fiber lighting device 1 of the present embodiment. The optical fiber bundle 10 has a light emitting portion covered by a resin jacket 101 and a light guiding portion that functions as a light guide 201 and is not covered by the resin jacket 101. The optical fiber bundle 10 has light guiding portions near both ends in the length direction, sandwiching the light emitting portion. The first light incident portion 20-1 includes a light source 200, a housing 202, and a switch 203. The light source 200 is a source of light incident on the optical fiber bundle 10, and may be, for example, a lamp, an LED, or a laser. The light source 200 is preferably a light source with a wide light distribution, that is, a light source that diffuses light over a wide range. In the present embodiment, the light source 200 is a visible light LED. In addition, the housing 202 accommodates the light source 200, the light guide 201, and a part of the switch 203, and is an accessory that determines the positional relationship between the light source 200 and the light guide 201. The housing 202 may be formed of, for example, resin or metal. In the present embodiment, the material of the housing 202 is resin. The switch 203 is an electronic accessory for making the light source 200 emit light. In this embodiment, when the switch 203 is turned on by the user of the optical fiber illumination device 1 , the LED of the light source 200 emits light, and the light is incident on the optical fiber bundle 10 .

[0029] As described above, the second light incident portion 20-2 has the same structure as the first light incident portion 20-1. That is, the second light incident portion 20-2 is provided with a light source 200, a housing 202, and a switch 203, as is the case with the first light incident portion 20-1. Here, in the case of distinguishing the light source 200 of the first light incident portion 20-1 from the light source 200 of the second light incident portion 20-2, the light source 200 of the first light incident portion 20-1 is expressed as the first light source 200-1. In addition, the light source 200 of the second light incident portion 20-2 is expressed as the second light source 200-2.

[0030] Figure 3 yes Figure 2 FIG. 2 is an enlarged view of the cross-sectional area A of the first light incident portion 20-1. In the first light incident portion 20-1, as far as the first light source 200-1 is concerned, the light emitting surface is disposed close to the first end portion 102 of the optical fiber bundle 10. The first light source 200-1 and the light guiding portion of the optical fiber bundle 10 are housed in a housing 202, and the positional relationship between the first light source 200-1 and the first end portion 102 is fixed. In the second light incident portion 20-2, as far as the second light source 200-2 is concerned, the light emitting surface is also disposed close to the second end portion of the optical fiber bundle 10. The positional relationship between the second light source 200-2 and the second end portion of the optical fiber bundle 10 is fixed by the housing 202 of the second light incident portion 20-2.

[0031] Figure 4 : is a cross-sectional view of the optical fiber bundle 10. The optical fiber bundle 10 has a middle portion 100 and a resin jacket 101 covering the middle portion 100 when observed in cross section. In the middle portion 100, a plurality of optical fibers 11 are bundled. In the present embodiment, the plurality of optical fibers 11 are covered with a flexible resin jacket 101 in a simply bundled state without being fixed by a curing agent or the like at least in the light-emitting portion of the optical fiber bundle 10. Therefore, the user can easily bend the light-emitting portion of the optical fiber lighting device 1. Each optical fiber 11 is a single-core optical fiber composed of a core 11a and a cladding 11b covering the outer circumference of the core 11a. In the present embodiment, the bundled plurality of optical fibers 11 are of the same type with respect to numerical aperture NA. However, the plurality of optical fibers 11 may also include two or more optical fibers with different numerical aperture NAs.

[0032] Generally, if the refractive index of the core 11a is n1, the refractive index of the cladding 11b is n2, and the outside of the optical fiber 11 is air (refractive index is 1), the numerical aperture NA of the optical fiber 11 is calculated by the following formula (1).

[0033] [Mathematical formula 1]

[0034]

[0035] When the core 11a and the cladding 11b are made of glass, for example, the refractive index n1 of the core 11a and the refractive index n2 of the cladding 11b are measured using the “optical refractive index measurement method” in the Japan Optical Glass Industries Association standard.

[0036] In formula (1), θ is the light receiving angle of the optical fiber 11. 2θ is called the aperture angle. From formula (1), it can be seen that, in terms of the optical fiber, if the difference between the refractive index n1 of the core 11a and the refractive index n2 of the cladding 11b is large, the numerical aperture NA becomes larger, and light in a larger angle range is received, and light is emitted in a wider angle range. On the contrary, in terms of the optical fiber, if the difference between the refractive index n1 of the core 11a and the refractive index n2 of the cladding 11b is small, the numerical aperture NA becomes smaller, and light in a narrower angle range is received, and light is emitted in a narrower angle range.

[0037] Here, in the present embodiment, the optical fiber 11 does not contain particles that scatter light, and no special method is used during its manufacture. For example, when the core 11a and the cladding 11b of the optical fiber 11 are made of glass, the optical fiber bundle 10 can be manufactured as follows. First, core glass and cladding glass are manufactured separately. The materials of the core glass and the cladding glass are multi-component glasses. Thereafter, the fiber is drawn by a double crucible method to obtain a single-core fiber, namely the optical fiber 11, in which the core glass and the cladding glass covering the core glass are concentrically arranged. The double crucible method refers to the use of a double crucible in which a core crucible and a cladding crucible are concentrically arranged, the core glass and the cladding glass in each crucible are heated, and a single-core fiber is continuously drawn (drawn) from the nozzle of the double crucible. Thereafter, the single-core fiber is cut into a predetermined length in a clean room. Then, as Figure 4 As shown, about 50 to 100,000 cut single-core fibers are bundled and covered with a resin jacket 101 to obtain an optical fiber bundle 10.

[0038] The optical fiber bundle 10 manufactured by the manufacturing method described above is excellent in mass production. However, the amount of light emitted from the side of such an optical fiber bundle 10 is low, and there is a problem that it is insufficient for lighting purposes. A method for solving this problem has been carefully studied, and it has been found that the amount of side light emission is improved by making the positional relationship between the light source 200 and the end of the optical fiber bundle 10 satisfy a predetermined relationship associated with the numerical aperture NA of the optical fiber 11. That is, the light source 200 and the end of the optical fiber bundle 10 of the optical fiber lighting device 1 of this embodiment can sufficiently increase the amount of side light emission by forming the positional relationship described below.

[0039] Figure 5 is a diagram illustrating the distance d between the light source 200 and the first end 102 of the optical fiber bundle 10 and the incident angle θ of the light. i As the distance d between the light source 200 and the first end 102 approaches, the incident angle θ of the light i becomes larger. Figure 5 In the example, the first end 102 of the optical fiber bundle 10 is used for explanation. For the second end, the incident angle θ i The relationship with the distance d is also the same.

[0040] As described above, the optical fiber 11 constituting the optical fiber bundle 10 has a predetermined numerical aperture NA, and the aperture angle 2θ is determined. Even if light is incident at an angle greater than the aperture angle 2θ, light that cannot be transmitted by the optical fiber 11 will be generated. In the past, in order to improve the transmission efficiency, a focusing lens was generally used to reduce the incident angle θ to 2θ. i Using a condenser lens is equivalent to increasing the distance d to a certain extent without reducing the amount of light.

[0041] In the optical fiber illumination device 1 of this embodiment, the first light source 200 - 1 is disposed close to the first end 102 without using a condenser lens so as to emit light in an angle range larger than the aperture angle 2θ of the plurality of optical fibers 11 to the optical fiber bundle 10 . Figure 6 This is a diagram showing the amount of side light emission when the distance d between the first light source 200 - 1 and the first end portion 102 is changed using the optical fiber 11 of Example 1 described later. Figure 6 The horizontal axis represents the distance d between the first light source 200-1 and the first end 102. Figure 6 The vertical axis is a light quantity ratio that relatively represents the change of the side light quantity. The vertical axis is represented by the ratio of the side light quantity when the first light source 200-1 is in contact with the first end 102, that is, when the distance d is zero, and is set to 1. Figure 6 As shown in the figure, if the distance d becomes larger, the side light emission decreases, so the light source 200 is preferably configured close to the first end 102. Preferably, the side light emission is greater than 1 / 4 compared to the case where the distance d is zero. Therefore, the so-called close means that the distance d is less than 2 mm. The so-called close is more preferably that the distance d is less than 1 mm. The so-called close is further preferably that the distance d is less than 0.5 mm. From the perspective of not reducing the side light emission, it is most preferred that the light source 200 is in contact with the end of the optical fiber bundle 10.

[0042] Here, if Fig.12 As shown, the distance d in Example 1 is the distance between the light emitting surface of the light source 200 (LED light emitting surface) and the first end 102 of the optical fiber bundle 10. Assuming that the light from the light source 200 is incident on the optical fiber bundle 10 via a focusing lens, the distance d is the distance between the focus of the focusing lens and the first end 102 of the optical fiber bundle 10. In addition, the distance L is the distance from the first end 102 along the length direction of the optical fiber bundle 10 (the direction in which the optical fiber bundle 10 extends). In addition, the distance h is the distance from a certain position on the surface of the optical fiber bundle 10 in a direction perpendicular to the length direction of the optical fiber bundle 10. The above-mentioned Figure 6In the measurement of the side emission amount, a measuring device (probe) for measuring the side emission amount is arranged to be separated from the optical fiber bundle 10 in a direction perpendicular to the longitudinal direction. Figure 6 In the example, the distance h to the measurement position is set to 1.0 mm. The definitions of the distance L and the distance h are also the same for the second end portion.

[0043] Figure 7 1 is a diagram showing the change in the amount of side light emission due to the difference in the incident angle of light. Figures 1 to 4 The structure described. In addition, the distance d between the LED of the light source 200 of Example 1 and the first end 102 of the optical fiber bundle 10 is less than 0.5 mm. The aperture angle 2θ of the optical fiber 11 is 120°, and the numerical aperture NA is 0.87. The second light incident part 20-2 of Example 1 is the same as the first light incident part 20-1. In this experiment, the switch 203 of the first light incident part 20-1 is turned on (ON), and the side of the optical fiber bundle 10 is illuminated by a light source 200. Moreover, the intensity of the light emission is measured every 50 mm from the first end 102 of the optical fiber bundle 10 to a position where the distance L is 1700 mm. At this time, the distance h to the measurement position is set to 1.0 mm. Here, the light emitting part of the optical fiber bundle 10 starts at a position 200 mm from the first end 102, so the initial measurement starts from this position.

[0044] The light source 200 of Comparative Example 1 is different from that of Example 1. In Comparative Example 1, an LED light source device (LS-L150, manufactured by Sumita Optical Glass Co., Ltd.) is used as the light source 200 instead of the LED fixed by the housing 202. The LED light source device used in Comparative Example 1 focuses the light of the LED by a lens and makes it incident on the optical fiber bundle 10. Therefore, the incident angle θ on the optical fiber bundle 10 is i That is, the angle 2θ is twice the incident angle. i The aperture angle is less than 2θ. The distance d in Comparative Example 1 (as mentioned above, in this case, it is the distance between the focus of the lens and the first end 102) is 0.5 mm. Here, the light amount of each light source is adjusted so that the incident light amount to the optical fiber bundle 10 in Example 1 and Comparative Example 1 is the same. The other aspects are the same as Example 1.

[0045] Figure 7 The horizontal axis of represents the measurement position using the distance L to the first end portion 102. Figure 7 The vertical axis represents the measured luminescence intensity. Figure 7As shown in the figure, at all distances L, the luminous intensity of Example 1 exceeds that of Comparative Example 1. That is, Example 1, which is a structure that emits light in an angle range larger than the aperture angle 2θ to the optical fiber bundle 10, has a higher side luminous amount than Comparative Example 1, showing that it is suitable for lighting purposes. It is believed that this is because the light in the angle range larger than the aperture angle 2θ leaks out from the inside of the optical fiber bundle 10 and contributes to the increase of luminous intensity.

[0046] Figure 8 This is a diagram showing the change in the amount of side light emission due to the difference in the numerical aperture NA of the optical fiber 11. From the perspective of practicality as lighting, Figure 7 In contrast, an experiment was conducted in which the types of the plurality of optical fibers 11 included in the optical fiber bundle 10 were changed. Figure 8 The horizontal axis and vertical axis are Figure 7 same.

[0047] Example 1 and Figure 7 The same as described in the experiment of . In Comparative Example 2, the aperture angle 2θ of the optical fiber 11 is 70°, and the numerical aperture NA is 0.57. In Comparative Example 3, the aperture angle 2θ of the optical fiber 11 is 15°, and the numerical aperture NA is 0.13. Comparative Examples 2 and 3 are the same as Example 1 except for the type of optical fiber 11.

[0048] like Figure 8 As shown in the figure, at all the measurement positions, the luminous intensity increases in the order of Example 1, Comparative Example 2, and Comparative Example 3. That is, the larger the numerical aperture NA, the higher the side luminous intensity, showing that it is suitable for lighting purposes. It is considered that this is because if the numerical aperture NA is small, the aperture angle 2θ is small, so a large amount of light leaks out near the first end 102, and the light cannot reach the light-emitting portion, so the side luminous intensity is reduced. Fig. 9 It is a diagram showing the relationship between the numerical aperture NA of the optical fiber and the light amount ratio. Fig. 9 The horizontal axis represents the numerical aperture NA. Fig. 9 The vertical axis is a ratio showing the change in the amount of light emitted from the side. The vertical axis is expressed as a ratio when the numerical aperture NA of the optical fiber 11 of Example 1 is set to 1. Fig. 9 As shown, when the numerical aperture NA is 0.75, the light quantity ratio is approximately 0.5. On the other hand, when the numerical aperture NA is 0.60, the light quantity ratio is approximately 0.25.

[0049] Here, in the optical fiber lighting device 1 in which the side light emission length is less than 5m, for example, from the perspective of practicality, it is preferred that the light emission intensity is at least about 5μW at a distance L of 1m from the first end 102. The distance h to the measurement position is 1.0mm. Example 1 has a light emission intensity that is more than twice of 5μW at a distance L of 1m from the first end 102. On the other hand, the light emission intensity of Comparative Examples 2 and 3 at a distance of 1m from the first end 102 is less than 5μW. In addition, when the numerical aperture NA is 0.75, as Fig. 9 As shown, the light quantity ratio relative to Example 1 is about 0.5, so the luminous intensity is about 5μW at a distance L of 1m from the first end 102. In this way, the numerical aperture NA of the multiple optical fibers 11 is preferably greater than 0.75. The numerical aperture NA of the multiple optical fibers 11 is more preferably greater than 0.80. The numerical aperture NA of the multiple optical fibers 11 is further preferably greater than 0.85. Here, in the case where the multiple optical fibers 11 are composed of different types of optical fibers 11, it is preferred that the average numerical aperture NA of the multiple optical fibers 11 is greater than 0.75. In addition, it is more preferred that all the numerical aperture NAs of the multiple optical fibers 11 are greater than 0.75.

[0050] The above embodiments are described based on the drawings and embodiments, but those skilled in the art can easily make various modifications and corrections based on the present disclosure. Therefore, it should be noted that these modifications and corrections are also included in the scope of the present disclosure. For example, each component, function, etc. can be reconfigured in a theoretically non-contradictory manner, and multiple components can be combined into one, or divided.

[0051] For example, in the above-mentioned embodiment, the first light incident portion 20-1 is described as one, and the second light incident portion 20-2 is described as one. However, at least one of the first light incident portion 20-1 and the second light incident portion 20-2 of the optical fiber illumination device 1 of the present disclosure may be multiple.

[0052] Fig.101 is a diagram showing the appearance of an optical fiber illumination device 1 of a modified example. The optical fiber illumination device 1 of this modified example includes a first light incident portion 20-1r for red, a first light incident portion 20-1g for green, and a first light incident portion 20-1b for blue. Each first light incident portion 20-1 has a first light source 200-1 for red, yellow, and blue, respectively. That is, the optical fiber illumination device 1 of this modified example has a plurality of first light sources 200-1. The plurality of optical fibers 11 of the optical fiber bundle 10 are divided into red, yellow, and blue at a branching point, and each has a first end 102. Moreover, each of the plurality of first light sources 200-1 is arranged close to each of the first ends 102 divided into a plurality of first ends. When the user uses the optical fiber illumination device 1 of this modified example and, for example, turns on the switch 203 of the first light incident portion 20-1r for red, the non-branched portion of the optical fiber bundle 10, that is, the light-emitting portion covered by the resin jacket 101, emits red light.

[0053] Fig.11 1 is a diagram showing the appearance of another modified example of the optical fiber illumination device 1. The first light incident portion 20 of the optical fiber illumination device 1 of this modified example is Fig.10 The optical fiber lighting device 1 of the modified example is the same as that of the modified example. In addition, the optical fiber lighting device 1 of the modified example includes a second light incident portion 20-2w for daylight color and a second light incident portion 20-2l for bulb color. Each second light incident portion 20-2 has a second light source 200-2 for daylight color and bulb color with different color temperatures. That is, the optical fiber lighting device 1 of the modified example has a plurality of second light sources 200-2. The plurality of optical fibers 11 of the optical fiber bundle 10 are divided into daylight color and bulb color at a branching point, and each has a second end. Moreover, each second light source of the plurality of second light sources 200-2 is arranged close to each second end of the second end divided into a plurality of second ends. When the user uses the optical fiber lighting device 1 of the modified example and, for example, turns on the switch 203 of the second light incident portion 20-2l for bulb color, the unbranched portion of the optical fiber bundle 10, that is, the light-emitting portion covered by the resin jacket 101, emits bulb color light. Fig.10 as well as Fig.11 The optical fiber lighting device 1 of the modified example can change the light emission color by the user and is therefore suitable for decorative purposes.

[0054] The records such as "first" and "second" in the present disclosure are identifiers for distinguishing the structures. The structures distinguished by the records such as "first" and "second" in the present disclosure can exchange the serial numbers of the structures. The identifiers are exchanged at the same time. The structures are also distinguished after the identifiers are exchanged. The identifiers can also be deleted. The structures from which the identifiers are deleted are distinguished by the figure marks. The order of the structures cannot be interpreted solely based on the records of the identifiers such as "first" and "second" in the present disclosure, and cannot be used as the basis for the existence of identifiers with small serial numbers.

[0055] Industrial Applicability

[0056] In various fields such as industrial and decorative fields, the optical fiber lighting device 1 of the present disclosure can be used, for example, as nighttime lighting, decorative lighting, or lighting for confirming the position or state of an assembly object. The optical fiber lighting device 1 of the present disclosure can be particularly suitable for guide displays, interior lights of vehicles, or exterior lights.

[0057] Description of Reference Numerals

[0058] 1 Fiber optic lighting device

[0059] 10 Fiber bundle

[0060] 11. Fiber Optics

[0061] 11a Core

[0062] 11b cladding

[0063] 20-1 First light incident part

[0064] 20-2 Second light incident part

[0065] 100 Middle

[0066] 101 Resin Jacket

[0067] 102 First end

[0068] 200 Light Source

[0069] 200-1 First Light Source

[0070] 200-2 Second Light Source

[0071] 201 Light pipe

[0072] 202 Shell

[0073] 203 switch.

Claims

1. A fiber optic lighting device, wherein: have: an optical fiber bundle having a first end and a second end that are polished, and having a plurality of optical fibers and a resin jacket that covers the plurality of optical fibers bundled to emit light; and a first light source disposed close to the first end portion so as to emit light having an angle range larger than an aperture angle of the plurality of optical fibers toward the optical fiber bundle; The numerical apertures of the multiple optical fibers are greater than 0.

75.

2. The optical fiber lighting device according to claim 1, wherein: The first light source is multiple, Each of the plurality of first light sources is disposed close to each of the first end portions divided into a plurality of first end portions.

3. The optical fiber lighting device according to claim 1, wherein: The optical fiber illumination device includes a second light source disposed close to the second end portion so as to emit light in an angle range larger than an aperture angle of the plurality of optical fibers toward the optical fiber bundle.

4. The optical fiber lighting device according to claim 2, wherein: The optical fiber illumination device includes a second light source disposed close to the second end portion so as to emit light in an angle range larger than an aperture angle of the plurality of optical fibers toward the optical fiber bundle.

5. The optical fiber lighting device according to claim 3, wherein: The second light source is multiple, Each of the plurality of second light sources is disposed close to each of the second end portions divided into a plurality of second end portions.

6. The optical fiber lighting device according to claim 4, wherein: The second light source is multiple, Each of the plurality of second light sources is disposed close to each of the second end portions divided into a plurality of second end portions.

7. The optical fiber lighting device according to any one of claims 1 to 6, wherein: The numerical apertures of the multiple optical fibers are greater than 0.

80.

8. The optical fiber lighting device according to any one of claims 1 to 6, wherein: The numerical apertures of the multiple optical fibers are greater than 0.85.

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