Image optical fiber, endoscope having the image optical fiber, and endoscope system having the endoscope

Abstract

The image optical fiber (23) comprises: a plurality of cores (61); and a cladding (63) which integrally surrounds the plurality of cores (61). In addition, the image optical fiber (23) further comprises: at least one optical fiber (75) which propagates illumination light; and an optical layer (70) which covers the outer peripheral surface of the cladding (63) over the entire circumference and contacts the outer peripheral surface of the optical fiber (75), so that the illumination light can propagate from the optical fiber (75) to the optical layer (70).

Description

Technical Field

[0001] The present invention relates to an image optical fiber, an endoscope having the image optical fiber, and an endoscope system having the endoscope. Background Art

[0002] For example, an endoscope having an elongated insertion portion is widely used in the industrial field or the medical field. The insertion portion is inserted into a subject to be examined so as to observe an object in the subject. Examples of the subject include structures such as an engine and a body cavity.

[0003] For example, Patent Document 1 discloses an image fiber optic cable that is mounted on an insertion portion of an endoscope and transmits imaging light and illumination light. The imaging light is light that represents an image of an object, and the illumination light is light that illuminates the object when observing the object including the image capture. The image fiber optic cable includes: an image optical fiber; a plurality of optical fibers arranged on the outer peripheral surface of the image optical fiber; and a ribbon that is spirally wound around the optical fiber. The imaging light is transmitted in the image optical fiber, and the illumination light is transmitted in the optical fiber. The plurality of optical fibers are fixed to the image optical fiber by the ribbon.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Publication No. 2010-169715 Summary of the invention

[0007] 1. Technical issues to be resolved

[0008] In the imaging optical fiber cable disclosed in Patent Document 1, a plurality of optical fibers are arranged on concentric circles, and a gap is formed between two adjacent circular optical fibers. Therefore, illumination light emitted from the plurality of optical fibers to an object may cause uneven illumination, and it is desired to suppress uneven illumination.

[0009] Therefore, an object of the present invention is to provide an image fiber capable of suppressing uneven irradiation of illumination light, an endoscope having the image fiber, and an endoscope system having the endoscope.

[0010] (II) Technical solution

[0011] In order to solve the above-mentioned technical problems, the image optical fiber of the present invention is characterized in that it comprises: a plurality of fiber cores; a cladding which integrally surrounds the plurality of fiber cores; at least one optical fiber which propagates illumination light; and an optical layer which covers the outer peripheral surface of the cladding throughout the circumference and contacts the outer peripheral surface of the optical fiber, and the illumination light can be propagated from the optical fiber to the optical layer.

[0012] In such an image fiber, the illumination light propagates in the optical fiber and can propagate from the optical fiber to the optical guide layer, and thus can propagate throughout the cross-section of the optical guide layer that covers the entire outer peripheral surface of the cladding. Therefore, according to the image fiber of the present invention, it is possible to suppress uneven illumination of the illumination light.

[0013] In addition, preferably, the optical waveguide layer has a coating layer composed of resin, the refractive index of the coating layer is higher than the refractive index of the cladding, and is the same as or higher than the refractive index of the optical fiber, and the optical fiber is arranged in at least a portion of the interior of the coating layer along the length direction of the optical waveguide layer.

[0014] The flexibility of the coating layer made of resin is generally better than that of the layer made of glass. Therefore, the coating layer has strong bending resistance and is closely attached to the outer peripheral surface such as the cladding layer to form a more stable configuration. Therefore, the deviation of the emission position of the illumination light is further suppressed, and the illumination light can be irradiated toward the object more stably. Therefore, according to the image optical fiber, the illumination light can be irradiated more stably.

[0015] In addition, if the refractive index of the coating is higher than that of the cladding, the propagation of the illumination light from the coating to the cladding can be suppressed. Therefore, according to the image optical fiber, the waste of illumination light can be suppressed. In addition, if the refractive index of the coating is the same as or higher than that of the optical fiber, it is easy to propagate the illumination light from the optical fiber to the coating, and a part of the illumination light propagates from the optical fiber to the coating and then propagates in the coating, and another part of the illumination light can propagate in the optical fiber. Therefore, according to the image optical fiber, the coating can be used more efficiently to propagate the illumination light to the optical fiber. In addition, since the illumination light propagates in the coating and is emitted from the coating, the emission range of the illumination light can be expanded compared to the case where the illumination light is emitted only from the optical fiber, and uneven illumination of the illumination light can be suppressed.

[0016] Furthermore, when the optical fiber is arranged at least partially inside the coating layer, the optical fiber is prevented from being displaced relative to the coating layer, and the optical fiber is in a stably arranged state. Furthermore, when the optical fiber is arranged at least partially inside the coating layer, the illumination light can be transmitted from the entire circumference of the outer peripheral surface of the optical fiber to the coating layer. Therefore, according to the image optical fiber, uneven illumination of the illumination light can be prevented.

[0017] In general, the thickness of the coating layer is controlled when manufacturing the imaging optical fiber and can be easily reduced in thickness. Therefore, according to this imaging optical fiber, the diameter of the imaging optical fiber can be easily reduced.

[0018] In addition, since the optical fiber is not arranged on the outer peripheral surface of the coating layer but is arranged in at least a part of the inside of the coating layer, according to the image optical fiber, it is possible to prevent the image optical fiber from becoming thicker. In addition, generally speaking, the optical fiber for propagating illumination light has a higher light propagation efficiency than the coating layer. Therefore, according to the image optical fiber, brighter illumination light can be irradiated.

[0019] In addition, preferably, the optical fiber is arranged from one end to the other end of the coating layer along the longitudinal direction of the optical guide layer.

[0020] In this case, the coating layer can effectively transmit the illumination light from one end of the coating layer to the other end using the optical fiber. Thus, a part of the illumination light is transmitted in the coating layer, and another part of the illumination light can be transmitted in the optical fiber. Therefore, according to the image optical fiber, the illumination light can be efficiently transmitted, and the uneven illumination of the illumination light can be suppressed.

[0021] Preferably, the optical waveguide layer further includes an outer low refractive index layer that covers the entire outer peripheral surface of the cladding layer, and the refractive index of the outer low refractive index layer is lower than that of the cladding layer.

[0022] In this case, the illumination light propagating in the coating layer is easily sealed in the coating layer by the outer low refractive index layer, and can propagate in the coating layer while preventing leakage from the coating layer to the outside of the image optical fiber. Therefore, according to this image optical fiber, the illumination light can be propagated more efficiently.

[0023] In addition, preferably, the optical waveguide layer includes a quartz layer having a refractive index higher than that of the cladding and the same as or higher than that of the optical fiber, and the optical fiber is arranged on at least a portion of the outer peripheral surface of the quartz layer along the length direction of the optical waveguide layer.

[0024] When manufacturing an image optical fiber, a plurality of core-clad optical fibers are generally inserted into a quartz tube in a bundled state, and melt and integrate with the quartz tube after insertion, and the quartz tube becomes a quartz layer. Therefore, even if the image optical fiber is bent, the quartz layer is integrated with the cladding, and the arrangement is stable.

[0025] In addition, if the refractive index of the quartz layer is higher than the refractive index of the cladding, the propagation of the illumination light from the quartz layer to the cladding can be suppressed. Therefore, according to this image optical fiber, the waste of illumination light can be suppressed. In addition, if the refractive index of the quartz layer is the same as or higher than the refractive index of the optical fiber, it is easy to propagate the illumination light from the optical fiber to the quartz layer, a part of the illumination light propagates from the optical fiber to the quartz layer, and then propagates in the quartz layer, and another part of the illumination light can propagate in the optical fiber. Therefore, according to this image optical fiber, the illumination light can be efficiently propagated to the quartz layer using the optical fiber, and the illumination light propagates in the quartz layer and is emitted from the quartz layer. Therefore, compared with the case where the illumination light is emitted only from the optical fiber, the emission range of the illumination light can be expanded, and the uneven irradiation of the illumination light can be suppressed.

[0026] Furthermore, if the optical fiber is disposed on at least a portion of the outer peripheral surface of the quartz layer along the longitudinal direction of the optical guide layer, a portion of the illumination light propagating in the optical fiber propagates from the optical fiber to the quartz layer and can propagate in the quartz layer. Therefore, according to the image optical fiber, uneven illumination of the illumination light can be suppressed.

[0027] In addition, preferably, the optical fiber is arranged from one end to the other end of the quartz layer along the length direction of the quartz layer.

[0028] In this case, the light guide layer can efficiently transmit the illumination light from one end of the quartz layer to the other end using the optical fiber. Therefore, according to the image optical fiber, the illumination light can be efficiently transmitted.

[0029] In addition, preferably, the optical waveguide layer further includes an inner low refractive index layer disposed between the cladding layer and the quartz layer, and the refractive index of the inner low refractive index layer is lower than the refractive index of the cladding layer.

[0030] In this case, the illumination light is easily sealed in the quartz layer by the inner low refractive index layer, and can propagate in the quartz layer while preventing leakage from the quartz layer to the core and cladding. Therefore, according to this image optical fiber, the illumination light can be propagated more efficiently.

[0031] In addition, preferably, the quartz layer has at least one groove provided in at least a portion of an outer peripheral surface of the quartz layer along a longitudinal direction of the optical guide layer, and at least a portion of the optical fiber in a radial direction is arranged in the groove.

[0032] At least a portion of the radial direction of the optical fiber is arranged in the groove, so that the optical fiber is stably arranged relative to the quartz layer. Therefore, even if the image fiber is bent, the displacement of the emission position of the illumination light is further suppressed, and the illumination light can be irradiated toward the object more stably. Therefore, according to the present image fiber, the illumination light can be stably irradiated.

[0033] Furthermore, an endoscope according to the present invention is characterized by comprising: an insertion portion inserted into a subject; and any one of the above-described image optical fibers disposed in an internal space of the insertion portion.

[0034] In this endoscope, since uneven irradiation of the illumination light can be suppressed, the endoscope can irradiate the object inside the subject with the illumination light with suppressed uneven irradiation.

[0035] In addition, the endoscope system of the present invention is characterized in that it comprises: the endoscope described above; a light source unit that emits the illumination light; an optical system that propagates the illumination light emitted from the light source unit to the optical fiber and captures the imaging light propagating in the fiber core, the imaging light being reflected light from an object irradiated with the illumination light; and a display unit that displays an image based on the imaging light captured by the optical system.

[0036] In this endoscope system, since the endoscope can irradiate the object with illumination light with suppressed irradiation unevenness, the display unit can display an image of the object with suppressed irradiation unevenness.

[0037] (III) Beneficial effects

[0038] As described above, according to the present invention, an object thereof is to provide an image fiber capable of suppressing uneven irradiation of illumination light, an endoscope having the image fiber, and an endoscope system having the endoscope. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a diagram showing an endoscope system according to a first embodiment of the present invention.

[0040] Figure 2 yes Figure 1 A cross-sectional view perpendicular to the length direction of the image optical fiber in an endoscope system.

[0041] Figure 3 Yes means Figure 2 The image shown is a diagram of the refractive index distribution in the optical fiber.

[0042] Figure 4 It is a cross-sectional view perpendicular to the longitudinal direction of the imaging optical fiber according to the second embodiment of the present invention.

[0043] Figure 5 Yes means Figure 4 The image shown is a diagram of the refractive index distribution in the optical fiber.

[0044] Figure 6 It is a cross-sectional view perpendicular to the longitudinal direction of the imaging optical fiber according to the third embodiment of the present invention. DETAILED DESCRIPTION

[0045] The preferred embodiment of the image optical fiber of the present invention is described in detail below with reference to the accompanying drawings. The embodiments illustrated below are used to facilitate the understanding of the present invention and are not used to limit the interpretation of the present invention. The present invention can be changed and improved without departing from its purpose. In addition, the present invention can appropriately combine the structural elements of each embodiment illustrated below. In addition, in order to facilitate understanding, some parts are exaggerated in each figure.

[0046] (First Embodiment)

[0047] Figure 1 1 is a diagram showing a schematic structure of an endoscope system 10 of the present invention. The endoscope system 10 includes an endoscope 20 used in, for example, the industrial field or the medical field. The endoscope 20 includes an elongated insertion portion 21 inserted into the subject, for example, to observe an object in the subject. Examples of the subject include structures such as an engine, a body cavity, and the like.

[0048] The insertion part 21 includes: an elongated image optical fiber 23, which is arranged along the entire length of the insertion part 21; an objective lens 25, which is arranged on the objective lens side of the image optical fiber 23; and a barrel component 27, which accommodates the image optical fiber 23 and the objective lens 25 in the internal space. The image optical fiber 23 is a component that transmits illumination light and imaging light. For example, the illumination light is visible light that illuminates an object, and the wavelength of the visible light is 400nm to 700nm. In addition, the imaging light is reflected light reflected from the object irradiated with the illumination light. The objective lens 25 is arranged at the front end of the insertion part 21. The barrel component 27 is preferably made of a metal component such as stainless steel, or a resin material. The barrel component 27 can be the outermost layer of the insertion part 21, or it can be a component arranged in the internal space of the insertion part 21.

[0049] The endoscope system 10 further includes a light source unit 30 that emits illumination light, and an optical system 40 that is optically connected to the light source unit 30 and the image optical fiber 23. The optical system 40 allows the illumination light from the light source unit 30 to be incident on the image optical fiber 23, and the imaging light emitted from the image optical fiber 23 to be incident on the optical system 40. In addition, the endoscope system 10 further includes a display unit 50 that displays an image based on an image signal generated by the optical system 40 according to the imaging light.

[0050] For example, LEDs are used for the light source unit 30. For example, a monitor is used for the display unit 50. The display unit displays, for example, still images or video. The image is, for example, two-dimensional.

[0051] The optical system 40 is connected to the eyepiece side of the endoscope 20. The optical system 40 includes a wavelength filter 41 and an imaging unit 43. The wavelength filter 41 reflects at least a portion of the illumination light emitted from the light source unit 30 toward the image optical fiber 23. In addition, at least a portion of the imaging light propagated from the image optical fiber 23 is transmitted to the wavelength filter 41. The imaging unit 43 captures the imaging light that has passed through the wavelength filter 41, and generates an image signal based on the imaging light. The imaging unit 43 outputs the generated image signal to the display unit 50. For example, a CCD camera or the like is used in the imaging unit 43.

[0052] In addition, the optical system 40 is further provided with lenses 45a, 45b, and 45c, which are arranged between the light source unit 30 and the wavelength filter 41, between the wavelength filter 41 and the image optical fiber 23, and between the wavelength filter 41 and the imaging unit 43. The lens 45a converts the illumination light traveling to the wavelength filter 41 into parallel light. For example, the lens 45b makes the cross-sectional area of ​​the illumination light variable so that the illumination light reflected by the wavelength filter 41 is incident on the optical fiber 75 described later. In addition, the lens 45b converts the imaging light propagating from the image optical fiber 23 into parallel light. The lens 45c focuses the imaging light to the imaging unit 43.

[0053] Next, use Figure 2 The image optical fiber 23 will be described. Figure 2 1 is a cross-sectional view perpendicular to the longitudinal direction of the image optical fiber 23 according to the present embodiment.

[0054] The image optical fiber 23 comprises: an image optical fiber main body 60, which is used to propagate the imaging light toward the optical system 40; a plurality of optical fibers 75, which are used to propagate the illumination light; and an optical layer 70, which covers the outer peripheral surface of the cladding 63 described later and covers the entire circumference and entire length of the image optical fiber main body 60, and the illumination light can be propagated from the optical fibers 75 to the optical layer 70.

[0055] The image fiber main body 60 has a cross-section perpendicular to the longitudinal direction in the shape of a circle, for example. The diameter of the circular image fiber main body 60 is, for example, 100 μm to 2500 μm.

[0056] The image fiber main body 60 is an elongated multi-core optical fiber having a plurality of cores 61 and a cladding 63 that integrally surrounds the plurality of cores 61. When manufacturing such an image fiber main body 60, a plurality of elongated core-cladding type optical fibers (not shown) are inserted into a quartz tube (not shown) in a bundled state and held in the quartz tube. When the bundled optical fibers are drawn together with the quartz tube, the claddings of the plurality of optical fibers soften and become one, forming a common cladding 63. In addition, when the claddings of the plurality of optical fibers soften and become one, the cladding 63 is fixed to the inner peripheral surface of the quartz tube, and the quartz tube becomes a part of the optical waveguide layer 70, that is, the quartz layer 71 described later. Thus, the image fiber main body 60 integral with the quartz layer 71 is formed.

[0057] In the cross section of the image fiber main body 60 perpendicular to the length direction, the cores 61 are arranged independently of each other, and the cladding 63 is continuously formed around the core 61 and closely fits the outer peripheral surface of the core 61 without any gap. In the cross section of the image fiber main body 60 perpendicular to the length direction, the core 61 is arranged roughly evenly as a whole. The so-called evenly arranged means that it is arranged in the entire area without being biased towards a part of the cross section of the image fiber main body 60. The spacing between the cores 61 is roughly constant. It should be noted that the spacing between the cores 61 may not be constant. The spacing is preferably 1 to 1.2 times the outer diameter of the core 61, for example. In addition, when observing the cross section of the image fiber main body 60 perpendicular to the length direction, the core 61 and the cladding 63 form an image circle.

[0058] The core 61 constitutes pixels that can be obtained using the image fiber 23. The number of cores 61 (number of pixels) is, for example, 3000 pixels to 50000 pixels. The core 61 is preferably made of, for example, quartz glass. A dopant having a high refractive index, such as germanium, is added to the quartz glass constituting the core 61.

[0059] The cross-sectional shape of the core 61 may be, for example, a square shape such as a circle or a hexagon, or an anisotropic shape such as an ellipse, a rectangle, a rectangle, or a rhombus. The following describes the case where the core 61 is a circle. The circular cores 61 have substantially the same outer diameter, and the outer diameter of the circular core 61 is, for example, 3 μm to 5 μm. In addition, the outer diameters of the circular cores 61 may be different from each other.

[0060] The cladding 63 is preferably made of, for example, quartz glass. A dopant such as fluorine may be added to the quartz glass constituting the cladding 63.

[0061] The optical waveguide layer 70 of the present embodiment includes: a quartz layer 71 covering the outer peripheral surface of the cladding layer 63 over the entire circumference and the entire length; and a coating layer 73 covering the outer peripheral surface of the quartz layer 71 over the entire circumference and the entire length.

[0062] The quartz layer 71 is closely attached to the outer peripheral surface of the cladding 63 without a gap by the above-mentioned fixing. Therefore, the quartz layer 71 covers the outer peripheral surface of the cladding 63 all around. The cross-sectional shape of the quartz layer 71 is a ring shape, and the thickness of the quartz layer 71 is, for example, 100 μm to 300 μm.

[0063] The coating layer 73 is made of, for example, a resin such as silicon or polyimide. The cross-sectional shape of the coating layer 73 is a ring shape, and the thickness of the coating layer 73 is, for example, 30 μm to 400 μm. The thickness of the coating layer 73 made of resin is controlled when manufacturing the image optical fiber 23.

[0064] The inner circumferential surface of the coating layer 73 is tightly attached to the outer circumferential surface of the quartz layer 71 without a gap. Therefore, the coating layer 73 covers the outer circumferential surface of the cladding 63 via the quartz layer 71 all around. In addition, the outer circumferential surface of the coating layer 73 is covered by the barrel member 27 and is bonded to the inner circumferential surface of the barrel member 27 by an adhesive material not shown. The coating layer 73 is also a protective member that buffers external forces acting from the outside and protects the image fiber body 60, the quartz layer 71, and the optical fiber 75 from being damaged by external forces. The so-called external force is, for example, a force acting on the image optical fiber 23 from the barrel member 27 when the insertion portion 21 is bent, or a force acting on the image optical fiber 23 from the inner wall through the barrel member 27 when the insertion portion 21 contacts the inner wall inside the subject.

[0065] The optical fiber 75 is optically connected to the light source unit 30 via the optical system 40. The optical fiber 75 is a component for the illumination light emitted from the light source unit 30 to enter and propagate via the optical system 40. In this case, for example, the lens 45b makes the cross-sectional area of ​​the illumination light variable as described above so that the illumination light enters the optical fiber 75. In addition, the lens 45b may focus the illumination light so that the illumination light enters the optical fiber 75. In addition, the optical fiber 75 may be optically connected to the light guide layer 70.

[0066] In the present embodiment, the optical fiber 75 is arranged inside the coating layer 73 along the longitudinal direction of the optical layer 70. In other words, the optical fiber 75 is not a component arranged in the internal space of the ring-shaped coating layer 73, but a component buried in the thick wall portion of the coating layer 73. Therefore, the outer peripheral surface of the optical fiber 75 is in contact with the coating layer 73 inside the coating layer 73, and the optical fiber 75 is protected by the coating layer 73 from the above-mentioned external force.

[0067] Preferably, in the cross section of the coating layer 73, the optical fibers 75 embedded in the coating layer 73 are arranged roughly uniformly over the entire wall thickness portion of the coating layer 73. The so-called uniform arrangement means that the optical fibers 75 are arranged over the entire area without being biased towards a part of the cross section of the coating layer 73. The optical fibers 75 may be arranged on the circumference of concentric circles centered on the center of the cross section of the coating layer 73. The optical fibers 75 adjacent to each other in the circumferential direction may be arranged separately from each other, or may be arranged closely fitting to each other without any gap. When the optical fibers 75 are separated from each other, the intervals between the optical fibers 75 in the circumferential direction are preferably equal, but may be different. The optical fibers 75 may be arranged in layers in the thickness direction of the coating layer 73. The optical fibers 75 are arranged separately from the quartz layer 71, but may be arranged in contact with the quartz layer 71.

[0068] The coating layer 73 may be formed into a sheet shape with the optical fiber 75 disposed inside the coating layer 73, and then added longitudinally to the outer peripheral surface of the quartz layer 71 to closely adhere to the outer peripheral surface of the quartz layer 71. Alternatively, after the optical fiber 75 is added longitudinally to the outer peripheral surface of the quartz layer 71, the resin, i.e., the coating layer 73, may be impregnated with the optical fiber 75 and the quartz layer 71 and coated.

[0069] In this embodiment, the optical fiber 75 is arranged from one end of the coating layer 73 to the other end of the coating layer 73 along the longitudinal direction of the optical guide layer 70. One end is the optical system 40 side, and the other end is the emission end for illumination light, that is, the objective lens 25 side.

[0070] The optical fiber 75 is made of plastic, for example, and ensures the bending resistance of the image optical fiber 23. The cross-sectional shape of the optical fiber 75 is, for example, circular. The diameter of the optical fiber 75 is, for example, 30 μm or more.

[0071] Here, use Figure 3 The refractive index distribution in the image optical fiber 23 will be described. Figure 3 : is a diagram showing the refractive index distribution in the image optical fiber 23 . Figure 3 The vertical axis represents the relative difference in refractive index of each component in the image optical fiber 23, Figure 3 The horizontal axis simplifies and shows the positional relationship of each component.

[0072] like Figure 3 As shown in the figure, in the image optical fiber body 60, the refractive index n63 of the cladding 63 is lower than the refractive index n61 of the core 61. The refractive index n71 of the silica layer 71 is lower than the refractive index n61 of the core 61, and higher than the refractive index n63 of the cladding 63. Figure 3 In the embodiment, the refractive index n75 of the optical fiber 75 is higher than the refractive index n71 of the quartz layer 71 and lower than the refractive index n73 of the coating layer 73. In addition, the refractive index n75 of the optical fiber 75 may be the same as the refractive index n73 of the coating layer 73. Figure 3 In the example, the refractive index n75 of the optical fiber 75 is the same as the refractive index n61 of the core 61, but may be higher or lower than the refractive index n61 of the core 61. The refractive index n73 of the coating layer 73 is higher than the refractive index n63 of the cladding layer 63 and the refractive index n71 of the silica layer 71.

[0073] Next, the operation of the endoscope system 10 will be described.

[0074] The insertion portion 21 of the endoscope 20 is inserted into the subject from the front end of the insertion portion 21, and the objective lens 25 is directed toward the object. The illumination light is emitted from the light source unit 30 toward the optical system 40, and is reflected toward the image optical fiber 23 by the wavelength filter 41 of the optical system 40. Then, the illumination light is incident from the optical system 40 to the optical fiber 75 of the image optical fiber 23, and propagates in the optical fiber 75.

[0075] The refractive index n75 of the optical fiber 75 of this embodiment is lower than the refractive index n73 of the coating layer 73. In this case, a part of the illumination light propagating in the optical fiber 75 propagates from the optical fiber 75 to the coating layer 73, and then propagates in the coating layer 73. In addition, another part of the illumination light propagates in the optical fiber 75 arranged from one end of the coating layer 73 to the other end along the longitudinal direction of the optical guide layer 70. In addition, the refractive index n71 of the quartz layer 71 is lower than the refractive index n73 of the coating layer 73 and the refractive index n75 of the optical fiber 75. Therefore, the illumination light propagates in the coating layer 73 and the optical fiber 75 in a state where leakage from the coating layer 73 and the optical fiber 75 to the quartz layer 71 is suppressed.

[0076] Then, the illumination light passes through the objective lens 25 and is emitted from the distal end of the insertion portion 21 toward the object, thereby irradiating the object.

[0077] The reflected light from the object, i.e., the imaging light, is incident on the core 61 of the image optical fiber main body 60 via the objective lens 25. Since the refractive index n61 of the core 61 is higher than the refractive index n63 of the cladding 63 and the refractive index n71 of the quartz layer 71, most of the imaging light propagates in the core 61 without leaking from the core 61 to the cladding 63 and the quartz layer 71. The imaging light travels from the image optical fiber main body 60 toward the optical system 40, passes through the wavelength filter 41, and is captured by the imaging unit 43. The imaging unit 43 generates an image signal based on the imaging light, and outputs the image signal to the display unit 50. The display unit 50 displays the image of the object based on the image signal.

[0078] As described above, the image optical fiber 23 of the present embodiment includes: a plurality of cores 61; a cladding 63 that integrally surrounds the plurality of cores 61; a plurality of optical fibers 75 that propagate illumination light; and an optical layer 70 that covers the entire outer peripheral surface of the cladding 63 and contacts the outer peripheral surface of the optical fiber 75, and the illumination light can propagate from the optical fiber 75 to the optical layer 70. In addition, in the present embodiment, a plurality of optical fibers 75 are arranged, but at least one optical fiber 75 may be arranged.

[0079] In such an image fiber 23, the illumination light propagates through the optical fiber 75 and can propagate from the optical fiber 75 to the optical guide layer 70, and can therefore propagate throughout the cross-section of the optical guide layer 70 that entirely covers the outer peripheral surface of the cladding 63. Therefore, according to the image fiber 23, uneven illumination of the illumination light can be suppressed.

[0080] In addition, since the illumination light propagates through the optical fiber 75 and the coating 73, and is emitted from the optical fiber 75 and the coating 73, the emission range of the illumination light can be expanded compared to the case where the illumination light is emitted only from the optical fiber 75. In addition, in the image optical fiber 23 of the present embodiment, the illumination light is incident on the coating 73 from the light source unit 30 via the optical system 40 and the optical fiber 75. Therefore, compared to the case where the illumination light is incident on the coating 73 from the light source unit 30 via the optical system 40, the illumination light can be easily incident on the coating 73.

[0081] In addition, even if the image optical fiber 23 is bent due to the bending of the insertion portion 21 inserted into the subject, the light guide layer 70 does not separate from the outer peripheral surface of the cladding 63 and is prevented from becoming unstable, thereby being stably arranged relative to the cladding 63. Thus, the displacement of the emission position of the illumination light at the front end of the insertion portion 21 is suppressed, and the illumination light can be stably irradiated toward the object. Therefore, the image optical fiber 23 can stably irradiate the illumination light.

[0082] In the image optical fiber 23 of the present embodiment, the optical layer 70 has a coating layer 73 made of resin, and the refractive index n73 of the coating layer 73 is higher than the refractive index n63 of the cladding layer 63 and the refractive index n75 of the optical fiber 75. The optical fiber 75 is arranged inside the coating layer 73 along the length direction of the optical layer 70. In the image optical fiber 23 of the present embodiment, the optical fiber 75 only needs to be arranged at least partially inside the coating layer 73. The so-called part refers to, for example, the part from one end of the coating layer 73 to the part between the one end of the coating layer 73 and the other end of the coating layer 73. In addition, as described above, the refractive index n73 of the coating layer 73 may be the same as the refractive index n75 of the optical fiber 75.

[0083] The flexibility of the coating layer 73 made of resin is generally better than that of a layer made of glass. Therefore, the coating layer 73 has strong bending resistance and is closely attached to the outer peripheral surface of the cladding 63 and the like, thereby forming a more stable configuration. Therefore, the deviation of the emission position of the illumination light is further suppressed, and the illumination light can be irradiated toward the object more stably. Therefore, according to the image optical fiber 23, the illumination light can be irradiated more stably.

[0084] In addition, if the refractive index n73 of the coating layer 73 is higher than the refractive index n63 of the cladding layer 63, the propagation of the illumination light from the coating layer 73 to the cladding layer 63 can be suppressed. Therefore, according to the image fiber 23, the waste of illumination light can be suppressed. In addition, if the refractive index n73 of the coating layer 73 is the same as or higher than the refractive index n75 of the optical fiber 75, the illumination light can be easily propagated from the optical fiber 75 to the coating layer 73, a part of the illumination light can be propagated from the optical fiber 75 to the coating layer 73, and then propagated in the coating layer 73, and another part of the illumination light can be propagated in the optical fiber 75. Therefore, according to the image fiber 23, the illumination light can be propagated to the optical fiber 75 using the coating layer 73 more efficiently. Furthermore, since the illumination light propagates through the coating layer 73 and is emitted from the coating layer 73 , the emission range of the illumination light can be expanded and uneven irradiation of the illumination light can be suppressed compared to the case where the illumination light is emitted only from the optical fiber 75 .

[0085] When the optical fiber 75 is arranged at least partially inside the coating 73, the optical fiber 75 is prevented from being displaced relative to the coating 73, and the optical fiber 75 is stably arranged. In addition, when the optical fiber 75 is arranged at least partially inside the coating 73, the illumination light can be propagated from the entire circumference of the outer peripheral surface of the optical fiber 75 to the coating 73. Therefore, according to the image optical fiber 23, uneven illumination of the illumination light can be prevented.

[0086] In general, the thickness of the coating layer 73 is controlled and can be easily reduced in thickness when manufacturing the image optical fiber 23. Therefore, according to the image optical fiber 23 of the present embodiment, the diameter of the image optical fiber 23 can be easily reduced.

[0087] In addition, since the optical fiber 75 is not disposed on the outer peripheral surface of the coating layer 73 but is disposed in at least a part of the inside of the coating layer 73, according to the image optical fiber 23, it is possible to prevent the image optical fiber 23 from becoming thicker in diameter. In addition, generally speaking, the optical fiber 75 for propagating illumination light has a higher light propagation efficiency than the coating layer 73. Therefore, according to the image optical fiber 23 of this embodiment, brighter illumination light can be irradiated.

[0088] In addition, since the optical fiber 75 is arranged inside the coating layer 73, interference between the optical fiber 75 and the quartz layer 71 can be suppressed. Therefore, breakage of the optical fiber 75 and the quartz layer 71 due to interference can be suppressed. The optical fiber 75 is not glass but plastic, and the quartz layer 71 is glass. Therefore, even if interference between the quartz layer 71 and the optical fiber 75 occurs, friction between the glass layers does not occur, and breakage of the quartz layer 71 and the optical fiber 75 can be suppressed. If the optical fiber 75 is plastic as described above, the image optical fiber 23 can ensure flexibility, and the image optical fiber 23 can ensure resistance to bending of the image optical fiber 23. In addition, when the image optical fiber 23 is connected to the optical system 40 through a connector or the like (not shown), if the optical fiber 75 is arranged inside the coating layer 73, the optical fiber 75 is suppressed from being untied, and the connection operation using the connector or the like can be easily performed.

[0089] In addition, in the image optical fiber 23 of the present embodiment, the optical fiber 75 is arranged from one end of the coating layer 73 to the other end along the longitudinal direction of the optical guide layer 70. In this case, the coating layer 73 can efficiently propagate the illumination light from one end of the coating layer 73 to the other end using the optical fiber 75. Thus, a part of the illumination light propagates in the coating layer 73, and another part of the illumination light can propagate in the optical fiber 75. Therefore, according to the image optical fiber 23 of the present embodiment, the illumination light can be efficiently propagated, and uneven illumination of the illumination light can be suppressed.

[0090] In this embodiment, the endoscope 20 includes an insertion portion 21 inserted into the subject, and the above-described image optical fiber 23 disposed in the internal space of the insertion portion 21. In the endoscope 20, since uneven illumination of the illumination light can be suppressed, the endoscope 20 can irradiate the object in the subject with illumination light with suppressed uneven illumination.

[0091] In addition, in the present embodiment, the endoscope system 10 includes the endoscope 20 described above, and the light source unit 30 that emits illumination light. In addition, the endoscope system 10 further includes: an optical system 40 that propagates the illumination light emitted from the light source unit 30 to the optical fiber 75, and captures the imaging light propagating in the core 61, the imaging light being the reflected light reflected from the object irradiated with the illumination light; and a display unit 50 that displays an image based on the imaging light captured by the optical system 40. In the endoscope system 10, since the endoscope 20 can irradiate the object with illumination light with suppressed irradiation unevenness, the display unit 50 can display an image of the object with suppressed irradiation unevenness.

[0092] (Second Embodiment)

[0093] Next, refer to Figure 4 and Figure 5The second embodiment of the present invention will be described in detail. Unless otherwise specified, the same reference numerals are used for the same or equivalent components as those of the first embodiment, and duplicate descriptions are omitted.

[0094] Figure 4 2 is a cross-sectional view perpendicular to the length direction of the image optical fiber 23 of the present embodiment. In the image optical fiber 23 of the present embodiment, the structure of the optical guide layer 70 is different from that of the optical guide layer 70 of the first embodiment, the position of the optical fiber 75 is different from that of the optical fiber 75 of the first embodiment, and the refractive index distribution in the image optical fiber 23 is different from that of the image optical fiber 23 of the first embodiment.

[0095] In the image optical fiber 23 of the present embodiment, the optical waveguide layer 70 further includes an outer low refractive index layer 81 that covers the outer peripheral surface of the coating layer 73 over the entire circumference and the entire length. The cross-sectional shape of the outer low refractive index layer 81 is, for example, a ring shape, and the inner peripheral surface of the outer low refractive index layer 81 is closely attached to the outer peripheral surface of the coating layer 73 without a gap. In addition, the outer peripheral surface of the outer low refractive index layer 81 is covered by the inner peripheral surface of the barrel member 27, and is bonded to the inner peripheral surface of the barrel member 27 by an adhesive material not shown. The outer low refractive index layer 81 is, for example, composed of a resin different from the coating layer 73. The resin of the outer low refractive index layer 81 is, for example, applied to the outer peripheral surface of the coating layer 73 and then hardened.

[0096] In the image optical fiber 23 of the present embodiment, the optical waveguide layer 70 further includes an inner low refractive index layer 83 disposed between the cladding 63 and the quartz layer 71. The cross-sectional shape of the inner low refractive index layer 83 is a ring shape, and the outer peripheral surface of the inner low refractive index layer 83 is covered by the inner peripheral surface of the quartz layer 71, and is closely attached to the inner peripheral surface of the quartz layer 71 without a gap. The inner peripheral surface of the inner low refractive index layer 83 covers the outer peripheral surface of the cladding 63, and is closely attached to the outer peripheral surface of the cladding 63 without a gap. The thickness of the inner low refractive index layer 83 is, for example, 2 μm to 20 μm.

[0097] For example, when manufacturing the image optical fiber body 60, before the bundled core-clad type optical fibers are inserted into the quartz tube, the inner low refractive index layer 83 is arranged on the inner peripheral surface of the quartz tube in advance. The inner low refractive index layer 83 is made of quartz that is a member different from the quartz layer 71 and to which a dopant such as fluorine is added to lower the refractive index.

[0098] In addition, the optical fiber 75 of the present embodiment is arranged on at least a portion of the outer peripheral surface of the quartz layer 71 along the longitudinal direction of the optical guide layer 70. In a state where a portion of the outer peripheral surface of the optical fiber 75 is in contact with the outer peripheral surface of the quartz layer 71, the remaining portion of the outer peripheral surface of the optical fiber 75 is covered by the coating layer 73. For example, the optical fiber 75 is arranged from one end to the other end of the quartz layer 71 along the longitudinal direction of the optical guide layer 70.

[0099] Used here Figure 5 The refractive index distribution in the image optical fiber 23 according to the present embodiment will be described. Figure 5 : is a diagram showing the refractive index distribution in the image optical fiber 23 . Figure 5 The vertical axis represents the relative difference in refractive index of each component in the image optical fiber 23. Figure 5 The horizontal axis simplifies and shows the positional relationship of each component.

[0100] In the image optical fiber 23 of the present embodiment, the refractive index n81 of the outer low refractive index layer 81 is lower than the refractive index n73 of the cladding layer 73. In addition, the refractive index n71 of the quartz layer 71 is higher than the refractive index n75 of the optical fiber 75. The refractive index n71 of the quartz layer 71 may be the same as the refractive index n75 of the optical fiber 75. The refractive index n83 of the inner low refractive index layer 83 is lower than the refractive index n63 of the cladding layer 63 and the refractive index n71 of the quartz layer 71.

[0101] Next, the propagation of illumination light in the optical fiber 75 and the optical guide layer 70 will be described.

[0102] As in the first embodiment, a part of the illumination light propagating through the optical fiber 75 propagates from the optical fiber 75 to the coating layer 73 and then propagates through the coating layer 73. In addition, another part of the illumination light propagates through the optical fiber 75.

[0103] In the present embodiment, the outer low refractive index layer 81 covers the outer peripheral surface of the coating layer 73 over the entire circumference, and the refractive index n81 of the outer low refractive index layer 81 is lower than the refractive index n73 of the coating layer 73. Therefore, the illumination light propagating in the coating layer 73 is easily sealed in the coating layer 73 by the outer low refractive index layer 81, and can propagate in the coating layer 73 while suppressing leakage from the coating layer 73 to the outside of the image optical fiber 23. Therefore, according to the image optical fiber 23 of the present embodiment, the illumination light can be propagated more efficiently.

[0104] In addition, the optical fiber 75 is arranged on at least a portion of the outer peripheral surface of the quartz layer 71 along the longitudinal direction of the optical layer 70. Therefore, a portion of the illumination light propagating in the optical fiber 75 propagates from the optical fiber 75 to the quartz layer 71, and then propagates in the quartz layer 71. Therefore, according to the image optical fiber 23, uneven illumination of the illumination light can be suppressed. In addition, the refractive index n71 of the quartz layer 71 is higher than the refractive index n63 of the cladding. Therefore, the illumination light is suppressed from propagating from the quartz layer 71 to the cladding 63. Therefore, according to the image optical fiber 23, waste of illumination light can be suppressed.

[0105] The optical fiber 75 is arranged from one end to the other end of the quartz layer 71 along the longitudinal direction of the optical layer 70. In this case, the optical layer 70 can efficiently propagate the illumination light from one end to the other end of the quartz layer 71 using the optical fiber 75. Therefore, according to the image optical fiber 23, the illumination light can be efficiently propagated.

[0106] In addition, the refractive index n71 of the quartz layer 71 is the same as or higher than the refractive index n75 of the optical fiber 75. In this case, the illumination light can be easily transmitted from the optical fiber 75 to the quartz layer 71, and a part of the illumination light can be transmitted from the optical fiber 75 to the quartz layer 71 and then transmitted in the quartz layer 71. In addition, another part of the illumination light can be transmitted in the optical fiber 75. Therefore, according to the image optical fiber 23, the illumination light can be efficiently transmitted to the quartz layer 71 using the optical fiber 75, and the illumination light can be transmitted in the quartz layer 71 and emitted from the quartz layer 71. Therefore, compared with the case where the illumination light is emitted only from the optical fiber 75, the emission range of the illumination light can be expanded, and the uneven irradiation of the illumination light can be suppressed.

[0107] In addition, the inner circumference of the quartz layer 71 is closely attached to the outer circumference of the inner low refractive index layer 83 without a gap, and the inner circumference of the inner low refractive index layer 83 is closely attached to the outer circumference of the cladding 63 without a gap. Therefore, even if the image optical fiber 23 is bent due to the bending of the insertion part 21 inserted into the subject, the quartz layer 71 is integrated with the cladding 63 via the inner low refractive index layer 83, so it becomes a stable configuration state. In addition, the displacement of the emission position of the illumination light at the front end of the insertion part 21 is further suppressed, and the illumination light can be irradiated toward the object more stably. Therefore, according to the image optical fiber 23, the illumination light can be stably irradiated.

[0108] In addition, the refractive index n83 of the inner low refractive index layer 83 is lower than the refractive index n63 of the cladding 63 and the refractive index n71 of the quartz layer 71. When the image optical fiber 23 is viewed from the perspective of refractive index, the inner low refractive index layer 83 is groove-shaped, and the image optical fiber 23 has a channel structure. With such a channel structure, the illumination light is easily sealed in the quartz layer 71 by the inner low refractive index layer 83, and can be propagated in the quartz layer 71 while suppressing leakage from the quartz layer 71 to the core 61 and the cladding 63. Therefore, according to the image optical fiber 23 of this embodiment, the illumination light can be efficiently propagated.

[0109] (Third Embodiment)

[0110] Next, refer to Figure 6 The third embodiment of the present invention will be described in detail. Unless otherwise specified, the same reference numerals are used for the same or equivalent components as those of the second embodiment, and duplicate descriptions are omitted.

[0111] Figure 6 2 is a cross-sectional view perpendicular to the longitudinal direction of the image fiber 23 of the present embodiment. In the image fiber 23 of the present embodiment, the structure of the light guide layer 70 is different from the structure of the light guide layer 70 of the second embodiment.

[0112] The quartz layer 71 of this embodiment has at least one groove 71a provided in at least a portion of the outer peripheral surface of the quartz layer 71 along the longitudinal direction of the optical guide layer 70. The groove 71a is mechanically arranged in the quartz layer 71 by cutting, for example, with a lathe or a milling cutter. At least a portion of the radial direction of at least one optical fiber 75 is arranged in the groove 71a.

[0113] In the cross-sectional shape of the quartz layer 71, the shape of the groove 71a can be any shape such as a V-shape or a concave shape so that the optical fiber 75 can enter. In the relationship between the depth of the groove 71a and the diameter of the optical fiber 75, a part of the optical fiber 75 can be accommodated in the groove 71a, and the remaining part of the optical fiber 75 can protrude outward from the outer peripheral surface of the quartz layer 71. In addition, if the entire optical fiber 75 is accommodated in the groove 71a, the image optical fiber 23 can be reduced in diameter. The optical fiber 75 can be fixed in the groove 71a by the resin of the coating layer 73, or fixed in the groove 71a by an adhesive material (not shown).

[0114] Similar to the optical fiber 75 buried in the coating layer 73 of the first embodiment, the optical fiber 75 in the groove 71 a is arranged from one end to the other end of the quartz layer 71 along the longitudinal direction of the quartz layer 71 .

[0115] In the present embodiment, at least a portion of the radial direction of the optical fiber 75 is arranged in the groove 71a, so that the optical fiber 75 is stably arranged relative to the quartz layer 71. Therefore, even if the image optical fiber 23 is bent due to the bending of the insertion portion 21 inserted into the subject, the emission position of the illumination light at the front end of the insertion portion 21 is further suppressed from being deviated, and the illumination light can be stably irradiated to the object. Therefore, according to the image optical fiber 23 of the present embodiment, the illumination light can be irradiated more stably.

[0116] In addition, the optical fiber 75 is not disposed on the outer peripheral surface of the quartz layer 71 but is disposed in at least a portion of the groove 71a, so that the image fiber 23 can be prevented from being thickened in diameter in the image fiber 23. In addition, the optical fiber 75 can be easily positioned by the groove 71a. Therefore, according to the image fiber 23 of the embodiment, the image fiber 23 can be easily manufactured, and the emission position of the illumination light emitted from the image fiber 23 can be controlled.

[0117] As mentioned above, although the present invention has been described by taking the above-mentioned respective embodiments as examples, the present invention is not limited thereto and can be modified appropriately.

[0118] For example, in the first embodiment, the coating layer 73 may be optically connected to the optical system 40, and the illumination light may directly enter the coating layer 73 from the optical system 40. Similarly, in the second embodiment, the coating layer 73 may be optically connected to the optical system 40, and the illumination light may directly enter the coating layer 73 from the optical system 40. In addition, the optical fiber 75 may protrude from the light guide layer 70 and extend toward the light source unit 30, and may be directly optically connected to the light source unit 30.

[0119] In the first to third embodiments, the optical fiber 75 disposed in the coating layer 73 may be disposed in a portion in the longitudinal direction of the coating layer 73. In this case, the optical fiber 75 is preferably disposed from the end portion on the side where light enters the optical guide layer 70 to the middle of the longitudinal direction of the coating layer 73. In this case, the illumination light incident on the optical fiber 75 propagates from the optical fiber 75 to the coating layer 73 in the middle of the longitudinal direction of the coating layer 73, and can be emitted from the coating layer 73.

[0120] In the third embodiment, the optical fiber 75 disposed in the groove 71a may be disposed in a portion of the length direction of the quartz layer 71. In this case, the optical fiber 75 is preferably disposed from the end of the optical fiber layer 70 where light enters to the middle of the length direction of the quartz layer 71.

[0121] In the second embodiment, at least one of the structure of the quartz layer 71 for propagating illumination light, the outer low refractive index layer 81 and the inner low refractive index layer 83 may be incorporated into the image optical fiber of the first embodiment.

[0122] In addition, in the second embodiment, if the refractive index n71 of the quartz layer 71 and the refractive index n73 of the coating layer 73 are higher than the refractive index n75 of the optical fiber 75, the refractive index n71 of the quartz layer 71 may be the same as the refractive index n73 of the coating layer 73, higher than the refractive index n73 of the coating layer 73, or lower than the refractive index n73 of the coating layer 73.

[0123] Furthermore, the groove 71 a described in the third embodiment and the optical fiber 75 disposed in the groove 71 a may be incorporated into the image optical fiber of the first and second embodiments.

[0124] The endoscope 20 may be a soft endoscope in which the insertion portion 21 has flexibility, or may be a hard endoscope in which the insertion portion 21 is kept straight and is resistant to bending.

[0125] According to the present invention, an image fiber capable of stably irradiating illumination light, an endoscope having the image fiber, and an endoscope system having the endoscope are provided, which can be used in various industries such as industrial fields and medical fields.

Claims

1. An imaging optical fiber, characterized in that: have: Multiple fiber cores; a cladding integrally surrounding the plurality of cores; at least one optical fiber that propagates illumination light; and a light guide layer that covers the outer peripheral surface of the cladding layer over its entire circumference and contacts the outer peripheral surface of the optical fiber, and the illumination light can propagate from the optical fiber to the light guide layer, The optical waveguide layer has a coating layer made of resin, The coating layer has a refractive index higher than that of the cladding layer and is the same as or higher than that of the optical fiber. The optical fiber is disposed in at least a portion of the coating layer along a longitudinal direction of the optical guide layer.

2. The image optical fiber according to claim 1, characterized in that: The optical fiber is arranged from one end to the other end of the coating layer along the longitudinal direction of the optical guide layer.

3. The image optical fiber according to claim 1 or 2, characterized in that: The optical waveguide layer further includes an outer low refractive index layer, and the outer low refractive index layer covers the outer peripheral surface of the coating layer over its entire circumference. The outer low-refractive-index layer has a refractive index lower than that of the covering layer.

4. The image optical fiber according to claim 1 or 2, characterized in that: The optical guide layer includes a quartz layer having a refractive index higher than that of the cladding layer and the same as or higher than that of the optical fiber. The optical fiber is disposed on at least a portion of the outer peripheral surface of the quartz layer along the longitudinal direction of the optical guide layer.

5. The image optical fiber according to claim 3, characterized in that: The optical guide layer includes a quartz layer having a refractive index higher than that of the cladding layer and the same as or higher than that of the optical fiber. The optical fiber is disposed on at least a portion of the outer peripheral surface of the quartz layer along the longitudinal direction of the optical guide layer.

6. The image optical fiber according to claim 4, characterized in that: The optical fiber is arranged from one end to the other end of the quartz layer along the length direction of the optical guide layer.

7. The image optical fiber according to claim 5, characterized in that: The optical fiber is arranged from one end to the other end of the quartz layer along the length direction of the optical guide layer.

8. The image optical fiber according to claim 4, characterized in that: The optical waveguide layer further includes an inner low refractive index layer disposed between the cladding layer and the quartz layer. The inner low-refractive-index layer has a refractive index lower than that of the cladding layer.

9. The image optical fiber according to any one of claims 5 to 7, characterized in that: The optical waveguide layer further includes an inner low refractive index layer disposed between the cladding layer and the quartz layer. The inner low-refractive-index layer has a refractive index lower than that of the cladding layer.

10. The image optical fiber according to claim 4, characterized in that: The quartz layer has at least one groove, and the groove is provided in at least a portion of the outer peripheral surface of the quartz layer along the length direction of the optical guide layer. At least a portion of the optical fiber in a radial direction is arranged in the groove.

11. The image optical fiber according to any one of claims 5 to 8, characterized in that: The quartz layer has at least one groove, and the groove is provided in at least a portion of the outer peripheral surface of the quartz layer along the length direction of the optical guide layer. At least a portion of the optical fiber in a radial direction is arranged in the groove.

12. The image optical fiber according to claim 9, characterized in that: The quartz layer has at least one groove, and the groove is provided in at least a portion of the outer peripheral surface of the quartz layer along the length direction of the optical guide layer. At least a portion of the optical fiber in a radial direction is arranged in the groove.

13. An endoscope, characterized in that: have: an insertion portion that is inserted into a subject; and The imaging optical fiber according to any one of claims 1 to 12, which is arranged in the internal space of the insertion portion.

14. An endoscope system, characterized in that: have: The endoscope according to claim 13; a light source portion that emits the illumination light; an optical system that propagates the illumination light emitted from the light source section to the optical fiber and captures imaging light propagating in the core, the imaging light being reflected light from an object irradiated with the illumination light; as well as A display unit displays an image based on the imaging light captured by the optical system.

Images