Linear light guide

Abstract

To improve easiness and certainty of fixing an optical fiber to a cylindrical member in a linear light guide body comprising the optical fiber, the cylindrical member for storing a tip end of the optical fiber, and a resin member mixed with light scattering particles.SOLUTION: A linear light guide body 3 comprises: an optical fiber 4 in which a core 41 through which light is propagated is covered with a cladding 42; a light-transmissive cylindrical member 5 for storing a tip end of the optical fiber 4; and a light scattering resin 6 that is mixed with light scattering particles 61 for scattering light being radiated from a tip end face 41a of the core 41 to an inside of the cylindrical member 5. In the optical fiber 4, an outer diameter D4 of a portion thereof which is stored in the cylindrical member 5 is smaller than an inner diameter D51 of the cylindrical member 5, and a part of the light scattering resin 6 is interposed between an outer peripheral surface 4a of the optical fiber 4 and an inner surface 5a of the cylindrical member 5, thereby the optical fiber 4 being fixed to the cylindrical member 5.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a linear light guide using an optical fiber. [Background technology]

[0002] BACKGROUND ART Conventionally, a linear light guide that guides light from a light source to a target site by an optical fiber and scatters and radiates light at the target site has been used in, for example, catheter treatment (see, for example, Patent Document 1).

[0003] The phototherapy device described in Patent Document 1 has an optical fiber diffusion tip assembly attached to the tip of an optical fiber whose core and cladding are coated with an outer buffer coating. This optical fiber diffusion tip assembly has a cylindrical housing into which the end of the optical fiber is inserted, and an end plug is disposed at the tip of the housing together with a mirror reflector. A scattering medium containing scattering particles is accommodated between the optical fiber and the mirror reflector within the housing. Light propagating through the core of the optical fiber is scattered by the scattering particles, passes through the housing, and is emitted to the outer periphery of the housing. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 10-504989 Summary of the Invention [Problem to be solved by the invention]

[0005] In the optical fiber diffusion tip assembly described in Patent Document 1, as shown in FIG. 1, the core and clad of an optical fiber are inserted into a housing together with an outer buffer coating. At the end of the housing into which the optical fiber is inserted, the housing bulges and clamps the optical fiber. With this method of fixing the optical fiber to the housing, it is difficult to push the optical fiber into the housing, and there is a risk that sufficient fixing strength may not be obtained.

[0006] Therefore, the present invention aims to improve the ease and reliability of fixing an optical fiber to a tubular member in a linear light guide comprising an optical fiber, a tubular member that houses the tip of the optical fiber, and a light-scattering resin mixed with light-scattering particles. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, the present invention provides a linear light guide comprising an optical fiber in which a core through which light propagates is covered with a cladding having a lower refractive index than the core, a light-transmitting tubular member that houses the tip end of the optical fiber, and a light-scattering resin mixed with light-scattering particles that scatter light emitted from the tip end surface of the core into the tubular member, wherein the outer diameter of the part of the optical fiber housed in the tubular member is smaller than the inner diameter of the tubular member, and a part of the light-scattering resin is interposed between the outer surface of the optical fiber and the inner surface of the tubular member, thereby fixing the optical fiber to the tubular member. [Effects of the Invention]

[0008] According to the linear light guide of the present invention, the optical fiber and the cylindrical member can be fixed more easily and reliably. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram showing a treatment device using a linear light guide according to an embodiment of the present invention as a catheter, together with a patient to be treated. [Figure 2]FIG. 2 is a schematic diagram showing a part of a linear light guide inserted into a patient's body. [Figure 3] FIG. 2 is a perspective view showing one end of a linear light guide. [Figure 4] 1(a) is a cross-sectional view of a linear light guide taken along its axial direction, and FIG. 1(b) is an enlarged cross-sectional view of a tip portion of the linear light guide. [Figure 5] 10(a) to 10(c) are explanatory views showing a process of fixing an optical fiber to a cylindrical member with a light scattering resin. [Figure 6] FIG. 10 is a cross-sectional view showing a linear light guide according to a second embodiment. [Figure 7] FIG. 10 is a cross-sectional view showing a linear light guide according to a third embodiment. [Figure 8] FIG. 10 is a cross-sectional view showing a linear light guide according to a fourth embodiment. [Figure 9] FIG. 10 is a cross-sectional view showing a linear light guide according to a fifth embodiment. [Figure 10] FIG. 10 is a cross-sectional view showing a linear light guide according to a sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] [First embodiment] 1 is a schematic diagram showing a treatment device using a linear light guiding body as a catheter according to a first embodiment of the present invention, together with a patient to be treated. The treatment device 1 has a main body 2 and a linear light guiding body 3, and the distal end of the linear light guiding body 3 is inserted into the body of the patient P. The main body 2 has a light source 21 that emits laser light, and the laser light generated by the light source 21 is incident on the proximal end of the linear light guiding body 3.

[0011] FIG. 2 is a schematic diagram showing a portion of the linear light guide 3 inserted into the body of a patient P. In FIG. 2, a portion of a blood vessel P1 of the patient P is cut away to show the linear light guide 3 inserted into the blood vessel P1 as an insertion object. The laser light Lr scattered and emitted from the linear light guide 3 irradiates the treatment area P2, causing a reaction with a drug that has been previously contained in the treatment area P2. In this way, intravascular laser treatment is performed.

[0012] Fig. 3 is a perspective view showing one end of the linear light conductor 3. Fig. 4(a) is a cross-sectional view of the linear light conductor 3 taken along the axial direction. Fig. 4(b) is an enlarged cross-sectional view of the tip of the linear light conductor 3.

[0013] The linear light guide 3 comprises an optical fiber 4 that guides the laser light generated by the light source 21 as propagating light to the treatment area P2, a light-transmitting tubular member 5 that houses the tip of the optical fiber 4, and a light-scattering resin 6 mixed with light-scattering particles 61 that scatter the light emitted from the tip surface 41a of the core 41 into the tubular member 5.

[0014] The optical fiber 4 is configured to have a core 41 through which light propagates, a clad 42 that covers the outer periphery of the core 41, and a sheath 43 that is a protective member that covers the outer periphery of the clad 42. In this embodiment, as an example, the core 41 is made of silica glass, and the clad 42 is made of a polymer. The sheath 43 is a fluorine-based resin, more specifically, ETFE (ethylene tetrafluoroethylene copolymer). The refractive index of the clad 42 is lower than that of the core 41, and light propagating through the core 41 within the clad 42 is totally reflected at the interface with the clad 42.

[0015] The tubular member 5 is made of a cylindrical resin with both ends open. Suitable resin materials for the tubular member 5 include optical plastics such as acrylic, styrene, polycarbonate, and polyolefin. At the tip of the optical fiber 4 housed in the tubular member 5, the core 41 and cladding 42 are exposed from the sheath 43, and only the core 41 and cladding 42 are housed in the tubular member 5. The core 41 is cleaved together with the cladding 42. Here, cleaving is a cutting method in which the core 41 and cladding 42 are locally bent to generate stress, and then cut by applying a diamond or super steel blade to the bent portion.

[0016] The light-scattering resin 6 has light-scattering particles 61 uniformly dispersed and mixed in a substrate 60 made of a stimulus-curable resin. "Dispersed and mixed" here means that the light-scattering particles 61 are mixed so that they are evenly dispersed throughout the substrate 60 and do not solidify in any part of the substrate 60. In this embodiment, the substrate 60 is a silicone resin that is thermosetting and light-transmitting. However, the substrate 60 may also be an ultraviolet-curable resin that is cured by ultraviolet light. The light-scattering particles 61 are metal particles that reflect light. In this embodiment, rutile-type titanium oxide (TiO2), which has a high refractive index, is used as the light-scattering particles 61. However, this is not limiting, and fine metal powders of aluminum oxide (alumina), silver, copper, iron, or alloys thereof may also be used as the light-scattering particles 61.

[0017] The outer diameter D4 of the optical fiber 4 housed in the cylindrical member 5 is equal to the inner diameter D of the cylindrical member 5. 51 In this embodiment, the outer diameter D4 of the optical fiber 4 housed in the cylindrical member 5 is smaller than the outer diameter D 42 The outer diameter D of the core 41 41 is, for example, 0.125 mm, and the outer diameter D of the cladding 42 42 The outer diameter D of the sheath 43 is, for example, 0.14 mm. 43 The inner diameter D of the cylindrical member 5 is, for example, 0.25 mm. 51 is, for example, 0.15 mm, and the outer diameter D 52 The outer diameter D4 of the optical fiber 4 housed in the cylindrical member 5 (the outer diameter D of the cladding 42) is, for example, 0.3 mm. 42 ) and the inner diameter D of the cylindrical member 5 51 The difference is, for example, 0.01 mm or more and 0.1 mm or less.

[0018] The optical fiber 4 and the tubular member 5 are fixed together by interposing a part of the light-scattering resin 6 between the outer peripheral surface 4a of the optical fiber 4 housed in the tubular member 5 and the inner surface 5a of the tubular member 5. In other words, the light-scattering resin 6 functions as an adhesive that fixes the optical fiber 4 and the tubular member 5 together.

[0019] The length L4 of the optical fiber 4 housed in the tubular member 5 is longer than the outer diameter D4 of the optical fiber 4 housed in the tubular member 5, and shorter than half the length L5 of the tubular member 5. If the length L4 of the optical fiber 4 inside the tubular member 5 is equal to or shorter than the outer diameter D4 of the optical fiber 4, the strength of fixing the optical fiber 4 to the tubular member 5 is not necessarily sufficient, and if the length L4 of the optical fiber 4 inside the tubular member 5 is equal to or longer than half the length L5 of the tubular member 5, the length of the light scattering resin 6 that scatters the light emitted from the tip surface 41 a of the core 41 becomes short.

[0020] A part of the light scattering resin 6 protrudes from a distal end 52, which is the end of the tubular member 5 opposite to the insertion end 51 of the optical fiber 4, to the outside of the tubular member 5. In this embodiment, this protruding part is a hemispherical tip 62. This tip 62 makes it easier to insert the linear light guide 3 into the blood vessel P1.

[0021] The light-scattering particles 61 in the light-scattering resin 6 are blended in a high concentration so as to sufficiently suppress the intensity of light radiated from the tip of the linear light guide 3 in the axial direction of the cylindrical member 5. Specifically, as shown in FIG. 4(a), the light-scattering particles 61 are blended in a high concentration so as to sufficiently suppress the intensity of light radiated from the tip of the linear light guide 3 in the axial direction of the cylindrical member 5. Specifically, as shown in FIG. 4(a), the light-scattering particles 61 are blended in a high concentration so as to sufficiently suppress the intensity of light radiated from the tip of the linear light guide 3 in the axial direction of the cylindrical member 5. 51 When a circular imaginary surface V having the same diameter as the core 41 is assumed, the intensity of the light passing through this imaginary surface V is 5% or less of the intensity of the light propagating through the core 41.

[0022] Next, referring to FIG. 5, an example of a method for fixing the optical fiber 4 to the tubular member 5 with the light-scattering resin 6 will be described. FIGS. 5(a) to 5(c) are explanatory views showing the process of fixing the optical fiber 4 to the tubular member 5. When fixing the optical fiber 4 to the tubular member 5, as shown in FIG. 5(a), the core 41 and cladding 42 exposed from the sheath 43 are inserted into the tubular member 5, and semi-solid light-scattering resin 6 before solidification is applied to the outer periphery of the tip end of the cladding 42. Then, as shown in FIG. 5(b), the optical fiber 4 and the tubular member 5 are moved relative to each other in the axial direction so that the tubular member 5 covers the semi-solid light-scattering resin 6. This allows the light-scattering resin 6 to be sufficiently distributed between the outer circumferential surface 4a of the optical fiber 4 housed in the tubular member 5 and the inner surface 5a of the tubular member 5.

[0023] 5(c), the light-scattering resin 6 is supplied to the distal end 52 of the tubular member 5 using a dispenser or the like to form a tip 62. The semi-solid light-scattering resin 6 protruding from the distal end 52 of the tubular member 5 naturally becomes hemispherical due to its surface tension, forming the tip 62. Thereafter, the light-scattering resin 6 is heated to harden the substrate 60, thereby fixing the optical fiber 4 to the tubular member 5.

[0024] In addition, if the light-scattering resin 6 is sufficiently filled inside the tubular member 5 by simply moving the optical fiber 4 and the tubular member 5 relative to each other so that the tubular member 5 is covered with the semi-solid light-scattering resin 6, and the tip 62 is formed, it is not necessary to additionally supply the light-scattering resin 6 to the distal end 52 of the tubular member 5 using a dispenser or the like.

[0025] According to the first embodiment described above, the optical fiber 4 can be easily and reliably fixed to the tubular member 5. Furthermore, since only the core 41 and the clad 42 of the optical fiber 4 are inserted into the tubular member 5, and the sheath 43 is not inserted, the diameter of the tubular member 5 can be made smaller than when the core 41 and the clad 42 are inserted into the tubular member 5 together with the sheath 43. This makes it easier to insert the linear light guide 3 into the blood vessel P1, and also reduces the burden on the patient P.

[0026] [Second embodiment] Next, a second embodiment of the present invention will be described with reference to Fig. 6. In the above-described first embodiment, the mixing ratio of light scattering particles 61 in the base material 60 of the light scattering resin 6 is uniform throughout, but in the second embodiment, the mixing ratio of light scattering particles 61 in the light scattering resin 6 increases stepwise with increasing distance from the tip surface 41a of the core 41 along the axial direction of the tubular member 5.

[0027] Fig. 6 is a cross-sectional view showing a linear light guide 31 according to the second embodiment. Fig. 6 shows an example in which the mixing ratio of light scattering particles 61 in a light scattering resin 6 increases in one step, and the light scattering resin 6 has a low-concentration region 6A and a high-concentration region 6B, which have different mixing ratios of light scattering particles 61 in a substrate 60. In the high-concentration region 6B, the concentration of the light scattering particles 61 is higher than in the low-concentration region 6A, and the concentration of the light scattering particles 61 in the high-concentration region 6B is, for example, at least twice the concentration of the light scattering particles 61 in the low-concentration region 6A.

[0028] 5(b), such a multi-layer structure of light-scattering resin 6 can be formed by covering a tubular member 5 with semi-solid light-scattering resin 6, and then additionally supplying a base material 60 containing a higher concentration of light-scattering particles 61 using a dispenser or the like. The low-concentration region 6A is distributed from the insertion end 51 of the optical fiber 4 in the tubular member 5 to the periphery of the tip surface 41a of the core 41, and the inside of the distal end 52 of the tubular member 5 and the tip 62 are formed by the high-concentration region 6B.

[0029] As a result, the intensity of light radiated from the tip end of the linear light guide 3 in the axial direction of the tubular member 5 is further reduced compared to the first embodiment. Also, the distribution of the intensity of light radiated to the outer periphery of the tubular member 5 is equalized in the axial direction of the tubular member 5. That is, light emitted from the tip end surface 41a of the core 41 travels through the substrate 60 while being scattered by the light scattering particles 61, and the intensity of the light gradually weakens as it approaches the distal end 52. However, in the present embodiment, the light is incident from the low-concentration region 6A to the high-concentration region 6B, making it easier for the light to be scattered in the high-concentration region 6B, and this prevents the intensity of the light radiated to the outer periphery of the tubular member 5 from weakening on the side of the distal end 52.

[0030] The mixing ratio of the light-scattering particles 61 in the light-scattering resin 6 may be changed in two or more stages so that the mixing ratio increases with increasing distance from the tip surface 41a of the core 41 along the axial direction of the cylindrical member 5. In this case, the distribution of the intensity of the light radiated to the outer periphery of the cylindrical member 5 can be made more uniform.

[0031] [Third embodiment] Next, a third embodiment of the present invention will be described with reference to Fig. 7. Fig. 7 is a cross-sectional view showing a linear light guide 32 according to the third embodiment.

[0032] In the third embodiment, of both end faces 5b, 5c of the tubular member 5, the end face 5b on the side where the optical fiber 4 is inserted is covered with the light scattering resin 6 together with the outer peripheral surface 4a of the optical fiber 4 in the vicinity of the insertion end 51. This further increases the fixing strength of the optical fiber 4 to the tubular member 5. Note that, in the example shown in Fig. 7, the entire end face 5b of the tubular member 5 is covered with the light scattering resin 6, but this is not limiting, and it is sufficient that at least a part of the end face 5b is covered with the light scattering resin 6.

[0033] Furthermore, in the third embodiment, a part of the light scattering resin 6 forms a tapered portion 63 on the outer periphery of the optical fiber 4 outside the tubular member 5. The tapered portion 63 covers the outer periphery 4a of the optical fiber 4 over a predetermined length range from one end face 5b of the tubular member 5, and has a tapered shape whose outer diameter becomes smaller as it goes away from the one end face 5b. This makes it possible to prevent the insertion end 51 of the tubular member 5 from getting caught when, for example, pulling out the linear light guide 32 from the blood vessel P1, and makes it possible to easily pull out the linear light guide 32.

[0034] [Fourth embodiment] Next, a fourth embodiment of the present invention will be described with reference to FIG. 8. FIG. 8 is a cross-sectional view showing a linear light guiding body 33 according to the fourth embodiment. In this linear light guiding body 33, an unfilled region 50, which is a space not filled with the light scattering resin 6, is formed inside the distal end 52 of the tubular member 5. Such a configuration of the linear light guiding body 33 can be obtained, for example, by curing the light scattering resin 6 in the state shown in FIG. 5(b). That is, in this embodiment, the linear light guiding body 33 can be manufactured more easily than in the first embodiment. Furthermore, it is possible to easily attach another member to the unfilled region 50 by fitting it thereto.

[0035] [Fifth embodiment] Next, a fifth embodiment of the present invention will be described with reference to Fig. 9. Fig. 9 is a cross-sectional view showing a linear light guide 34 according to the fifth embodiment. In this linear light guide 34, an unfilled region 50, which is not filled with light-scattering resin 6, is formed inside a distal end 52 of a tubular member 5, and a guide wire 7 serving as a guide member is attached to the distal end 52 of the tubular member 5.

[0036] The guidewire 7 includes a distal guide 71, a helix 72 formed by helically winding a wire rod, a plug 73 fixed to the distal end 52 of the tubular member 5, and a reinforcing wire 74 fixed to the plug 73. The distal guide 71, the helix 72, the plug 73, and the reinforcing wire 74 are made of, for example, medical-grade stainless steel. The distal guide 71 integrally includes a hemispherical portion 711 and a cylindrical portion 712 having a smaller diameter than the hemispherical portion 711, and the cylindrical portion 712 is fitted into one end of the helix 72. A portion of the plug 73 is fitted into the other end of the helix 72. Another portion of the plug 73 is fitted into the non-filled region 50. The reinforcing wire 74 is formed so that its outer diameter gradually decreases from the plug 73 toward the distal guide 71, reinforcing the bending rigidity of the helix 72.

[0037] According to this embodiment, the linear light conductor 34 is provided with the guide wire 7, which makes it easier to insert the linear light conductor 34 into the blood vessel P1.

[0038] [Sixth embodiment] Next, a sixth embodiment of the present invention will be described with reference to Fig. 10. Fig. 10 is a cross-sectional view showing a linear light guide 35 according to the sixth embodiment. In the above-described first to fifth embodiments, a portion of the sheath 43 of the optical fiber 4 is removed, and the core 41 and clad 42 exposed from the sheath 43 are disposed in the tubular member 5. However, in the linear light guide 35 according to the sixth embodiment, the core 41 and clad 42 at the tip end of the optical fiber 4 are housed together with the sheath 43 in the tubular member 5 without removing the sheath 43. The optical fiber 4 is fixed by a light-scattering resin 6 interposed between an outer peripheral surface 43a of the sheath 43 and an inner surface 5a of the tubular member 5.

[0039] In the example shown in FIG. 10, the outer diameter D 41 is 0.100 mm, and the outer diameter D of the glass cladding 42 42 The sheath 43 is made of, for example, PI (polyimide) and has an outer diameter D 43 The cylindrical member 5 has an inner diameter D 51 is 0.15 mm, and the outer diameter D52 The outer diameter D of the sheath 43, which is the outer diameter of the optical fiber 4 housed in the cylindrical member 5, is 0.30 mm. 43 and the inner diameter D of the cylindrical member 5 51 The difference is, for example, 0.01 mm or more and 0.1 mm or less.

[0040] According to this embodiment, the core 41 and the clad 42 are entirely covered by the sheath 43, with no exposed portions of the core 41 and the clad 42, so that the core 41 and the clad 42 can be protected by the sheath 43 and the strength of the linear light guide 35 against bending stress can be increased. Furthermore, there is no need to strip off the sheath 43 at the end of the optical fiber 4, which simplifies the manufacturing process.

[0041] 10, a portion of the light-scattering resin 6 protrudes outward from the distal end 52 of the tubular member 5 to form a spherical tip 62. However, the present invention is not limited to this. For example, as in a second embodiment shown in FIG. 6, the mixing ratio of light-scattering particles 61 in the light-scattering resin 6 may gradually increase with increasing distance from the distal end surface 41a of the core 41 along the axial direction of the tubular member 5. Furthermore, as in a third embodiment shown in FIG. 7, a portion of the light-scattering resin 6 may form a tapered portion on the outer periphery of the sheath 43 outside the tubular member 5. Furthermore, as in a fourth embodiment shown in FIG. 8, a non-filled region where the light-scattering resin 6 is not filled may be formed inside the distal end 52 of the tubular member 5. Furthermore, as in a fifth embodiment shown in FIG. 9, a plug 73 may be fitted into the non-filled region to attach the guidewire 7.

[0042] (Summary of the embodiment) Next, the technical ideas grasped from the above-described embodiments will be described by using the reference numerals and the like in the embodiments. However, the reference numerals in the following description do not limit the components in the claims to the members and the like specifically shown in the embodiments.

[0043] [1] An optical fiber (4) is provided, in which a core (41) through which light propagates is covered with a clad (42) having a refractive index lower than that of the core (41), a light-transmitting tubular member (5) that houses the tip end of the optical fiber (4), and a light-scattering resin (6) that contains light-scattering particles (61) that scatter light emitted from the tip end surface (41a) of the core (41) into the tubular member (5), wherein the outer diameter (D4) of the optical fiber (4) housed in the tubular member (5) is smaller than the inner diameter (D 51 ), and a part of the light-scattering resin (6) is interposed between the outer peripheral surface (4a) of the optical fiber (4) and the inner surface (5a) of the tubular member (5), thereby fixing the optical fiber (4) and the tubular member (5).

[0044] [2] The linear light guide (3, 31 to 34) according to the above [1], wherein the length (L4) of the optical fiber (4) housed in the tubular member (5) is longer than the outer diameter (D4) of the optical fiber (4) housed in the tubular member (5) and shorter than half the length (L5) of the tubular member (5).

[0045] [3] The linear light guide (3, 31 to 34) according to [1] or [2] above, wherein the optical fiber (4) has a sheath (43) that covers the clad (42), and the core (41) and the clad (42) are exposed from the sheath (43) in the portion housed in the tubular member (5).

[0046] [4] The linear light guide (35) according to [1] or [2] above, wherein the optical fiber (4) has the core (41) and the clad (42) covered with a sheath (43), and the core (41) and the clad (42) together with the sheath (43) are housed in the tubular member (5).

[0047] [5] A linear light guide (3, 31, 32, 35) according to any one of [1] to [4] above, wherein a portion of the light scattering resin (6) protrudes from the end (distal end 52) of the tubular member (5) opposite the insertion end (51) of the optical fiber (4) to the outside of the tubular member (5).

[0048] [6] The linear light guide (3, 31, 32, 35) according to the above [5], wherein the light scattering resin (6) of the protruding portion (tip 62) is hemispherical.

[0049] [7] A linear light guide (33, 34) according to any one of [1] to [4] above, wherein an unfilled region (50) not filled with the light scattering resin (6) is formed inside the end (52) of the tubular member (5) opposite the insertion end (41) of the optical fiber (4).

[0050] [8] The linear light guide (34) described in [7] above, further comprising a guide member (guide wire 7) for guiding the insertion of the tubular member (5) and the optical fiber (4) into the insertion target (blood vessel P1), and the guide member (7) is fitted and attached to the non-filled region (50).

[0051] [9] A linear light guide (32) according to any one of [1] to [8] above, wherein at least a portion of one of the end faces (5b, 5c) of the tubular member (5) into which the optical fiber (4) is inserted is covered with the light-scattering resin (6).

[0052]

[10] The linear light guide (32) described in [9] above, wherein a part (tapered portion 63) of the light scattering resin (6) covers the outer surface (4a) of the optical fiber (4) outside the tubular member (5) over a predetermined length range from the one end face (5b), and has a tapered shape in which the outer diameter becomes smaller as it goes away from the one end face (5a).

[0053]

[11] The linear light guide (31) according to any one of [1] to

[10] above, wherein the light-scattering resin (6) has a gradually increasing proportion of the light-scattering particles (61) mixed therein, as it moves away from the tip surface (41a) of the core (41) along the axial direction of the tubular member (5).

[0054] The present invention has been described above in accordance with the first to sixth embodiments, but the above-described embodiments do not limit the scope of the invention as claimed. It should be noted that not all of the combinations of features described in the embodiments are necessarily essential to solving the problems of the invention. The present invention can be modified and implemented as appropriate without departing from the spirit of the invention. For example, the first to fifth embodiments can be combined and implemented. [Explanation of symbols]

[0055] 3, 31 to 34... Linear light guide 4... Optical fiber 41... Core 41a... Tip surface 42... Cladding 43... Sheath 4a...outer circumferential surface 5...cylindrical member 50...Non-filling region 51...Insertion end 52...distal end 5a...inner surface 5b,5c...End face 6...Light scattering resin 60...Base material 61...Light scattering particles 62... Tip end 63... Tapered portion 7...Guide wire (guide member)

Claims

1. The optical fiber includes an optical fiber having a core through which light propagates, covered with a clad having a refractive index lower than that of the core, a light-transmitting tubular member that houses a tip end of the optical fiber, and a light-scattering resin that contains light-scattering particles that scatter light emitted from the tip end surface of the core into the tubular member, the outer diameter of the optical fiber housed in the cylindrical member is smaller than the inner diameter of the cylindrical member; a part of the light scattering resin is interposed between the outer peripheral surface of the optical fiber and the inner surface of the tubular member, thereby fixing the optical fiber to the tubular member; an unfilled region that is not filled with the light scattering resin is formed inside an end of the tubular member opposite to the insertion end of the optical fiber; a guide member that guides the insertion of the cylindrical member and the optical fiber into an insertion target is fitted and attached to the non-filled region; Linear light guide.

2. the length of the optical fiber housed in the tubular member is longer than the outer diameter of the optical fiber housed in the tubular member and shorter than half the length of the tubular member; The linear light conductor according to claim 1 .

3. The optical fiber has a sheath that covers the clad, and the core and the clad are exposed from the sheath at a portion housed in the tubular member. The linear light conductor according to claim 1 or 2.

4. The optical fiber has a clad covered with a sheath, and the core and the clad together with the sheath are housed in the tubular member. The linear light conductor according to claim 1 or 2.

5. At least a portion of one of both end faces of the cylindrical member, into which the optical fiber is inserted, is covered with the light scattering resin. The linear light conductor according to claim 1 .

6. a portion of the light scattering resin covering the outer peripheral surface of the optical fiber over a predetermined length range from the one end face on the outside of the tubular member, and having a tapered shape in which the outer diameter decreases as it gets farther from the one end face; The linear light conductor according to claim 5 .

7. the light-scattering resin has a mixing ratio of the light-scattering particles that gradually increases with increasing distance from the tip end surface of the core along the axial direction of the cylindrical member; The linear light conductor according to claim 1 .

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