Optical device, wireless endoscope, and endoscope system

Abstract

Provided is an optical device, wireless endoscope, and endoscope system in which a tubular portion is thin and in which illumination light can be efficiently incident on a light guide member inside the tubular portion. An optical device (1) has a holding portion (2) and a tubular portion (3), wherein the optical device (1) further has: a light source (11); a light guide member (12) formed of a medium having a larger refractive index than (1); and a light conversion member, the light guide member including a first light guide region (12') having an incident end face (2a) and a second light guide region (12") having an exit end face (12b), the diameter of the incident end face (12a) being larger than the diameter of the exit end face (12b), and at least a portion of the second light guide region (12") being included in the tubular portion.

Description

TECHNICAL FIELD

[0001] The present application relates to an optical device, a wireless endoscope, and an endoscope system. BACKGROUND

[0002] As an optical device, an endoscope is known. The endoscope has an elongated tubular portion. In a flexible endoscope, the tubular portion uses a soft tubular portion. In a rigid endoscope, the tubular portion uses a hard tubular portion. At least a part of the tubular portion is inserted into, for example, a body or a metal pipe.

[0003] In the endoscope, an optical fiber is arranged inside the tubular portion. Illumination light travels in the optical fiber and exits from a distal end of the tubular portion. If the diameter of the optical fiber is large, the illumination light can be efficiently incident to the optical fiber.

[0004] If the diameter of the optical fiber is large, the thickness of the tubular portion becomes thick. If the thickness of the tubular portion becomes thick, it is not easy to insert into, for example, a body or a metal pipe. In the case where the tubular portion is a soft tubular portion, an operation of bending the tubular portion becomes difficult.

[0005] Further, a camera element and an optical system are arranged inside the tubular portion. Also, a through-hole for a treatment instrument to pass through is sometimes formed inside the tubular portion. Therefore, if the diameter of the optical fiber becomes thick, the degree of freedom of layout becomes less.

[0006] An illumination unit using a light guide member is disclosed in Patent Literature 1, Patent Literature 2, and Patent Literature 3.

[0007] The illumination unit of Patent Literature 1 has an optical fiber and a light diffusion element. A tapered portion is provided in the optical fiber. In the tapered portion, the diameter thereof gradually becomes smaller toward the light diffusion element side.

[0008] The illumination unit is arranged in a distal end portion. The distal end portion is located at a distal end of an insertion portion. The insertion portion has the distal end portion, a bending portion, and a flexible tube portion.

[0009] The illumination unit of Patent Literature 2 has an optical fiber, a filter, and a lens. A metal plating layer is formed on the outer periphery of a distal end region of the optical fiber. In the distal end region, the diameter of the optical fiber becomes small.

[0010] The illumination unit is arranged in an endoscope distal end portion. The endoscope distal end portion is located at a distal end of an endoscope main body. The endoscope main body is insertable into a body cavity and has flexibility between the endoscope distal end portion and an endoscope proximal end portion.

[0011] The illumination unit of Patent Literature 3 has a plurality of LD cores, a light guide member, a mirror, and a light emitter. The plurality of LD cores are arranged side by side. In the light guide member, the diameter of one end is larger than the diameter of the other end.

[0012] Prior art documents

[0013] Patent documents

[0014] Patent Literature 1: Japanese Patent Application Laid-Open No. 2012-050607

[0015] Patent Literature 2: International Publication No. 2013 / 061590

[0016] Patent Literature 3: Japanese Patent No. 5172987 SUMMARY

[0017] PROBLEMS TO BE SOLVED BY THE INVENTION

[0018] In the illumination unit of Patent Literature 1, the diameter of the optical fiber up to the tapered portion is large. As described above, the illumination unit is disposed at the distal end portion. In this case, the optical fiber having a large diameter is disposed at the distal end portion, the curved portion, and the flexible tube portion. Therefore, the thickness of the insertion portion becomes thick. As a result, it is not easy to insert into the body or the metal tube. In addition, the degree of freedom of layout becomes less.

[0019] In the illumination unit of Patent Literature 2, the diameter of the optical fiber up to the distal end region is large. As described above, the illumination unit is disposed at the distal end portion of the endoscope. In this case, the optical fiber having a large diameter is disposed at the main body of the endoscope. Therefore, the thickness of the main body of the endoscope becomes thick. As a result, it is not easy to insert into the body or the metal tube. In addition, the degree of freedom of layout becomes less.

[0020] If the diameter of the optical fiber is reduced, the illumination light cannot be efficiently incident to the optical fiber.

[0021] In the illumination unit of Patent Literature 3, a plurality of LD cores are disposed in parallel. Therefore, the size of the illumination unit itself is large. In this case, if the illumination unit is disposed at the distal end of the tubular portion, the thickness of the tubular portion becomes thick. As a result, it is not easy to insert into the body or the metal tube. In addition, the degree of freedom of layout becomes less.

[0022] The present application was made in view of such a problem, and an object thereof is to provide an optical device, a wireless endoscope, and an endoscope system in which the thickness of a tubular portion is thin and in which illumination light can be efficiently incident to a light guide member in the tubular portion.

[0023] MEANS FOR SOLVING THE PROBLEM

[0024] In order to achieve the object to solve the above-described problem, the optical device of at least several technical solutions of the present application has a holding portion and a tubular portion, characterized in that,

[0025] The optical device further has:

[0026] a light source;

[0027] a light guide member formed of a medium having a refractive index greater than 1; and

[0028] a light conversion member,

[0029] the holding portion is positioned at a position closer to the light source than the tubular portion,

[0030] light emitted from the light source is incident on the incident end surface of the light guide member,

[0031] light emitted from the exit end surface of the light guide member is radiated toward the light conversion member,

[0032] the light guide member includes a first light guide region having the incident end surface and a second light guide region having the exit end surface,

[0033] the diameter of the incident end surface is greater than the diameter of the exit end surface,

[0034] at least a portion of the second light guide region is contained in the tubular portion.

[0035] Furthermore, the wireless endoscope according to at least several technical solutions of the present application is characterized in that,

[0036] the wireless endoscope has:

[0037] an insertion portion that is elongated and has flexibility; and

[0038] an operation portion that is provided at a rear end of the insertion portion,

[0039] the insertion portion has:

[0040] a front end portion that is provided at a front end of the insertion portion;

[0041] a curved portion that is provided at a rear end of the front end portion; and

[0042] a flexible tube portion that extends from a rear end of the curved portion to a front end of the operation portion,

[0043] a light source is disposed at a position closer to the operation portion than to the rear end of the insertion portion,

[0044] a light conversion member is disposed at the front end portion,

[0045] a light guide member formed of a medium having a refractive index greater than 1 is disposed between the light source and the light conversion member,

[0046] light emitted from the light source is incident on the incident end surface of the light guide member,

[0047] light emitted from the exit end surface of the light guide member is radiated toward the light conversion member,

[0048] the light guide member includes a first light guide region having the incident end surface and a second light guide region having the exit end surface,

[0049] The diameter of the incident end face is larger than the diameter of the exit end face.

[0050] At least a portion of the second light-guiding region is included in the insertion section.

[0051] Furthermore, the endoscopic system of at least several technical solutions of the present invention is characterized in that,

[0052] This endoscopic system has the following features:

[0053] The aforementioned optical devices or wireless endoscopes; and

[0054] Processing device.

[0055] The effects of the invention

[0056] According to the present invention, an optical device, a wireless endoscope, and an endoscope system are provided that can provide an optical portion with a finer diameter and can efficiently incident illumination light into a light guide member within the tubular portion. Attached Figure Description

[0057] Figure 1 This is a diagram illustrating the optical device of this embodiment.

[0058] Figure 2 This is a diagram illustrating the optical device of this embodiment.

[0059] Figure 3 This is a diagram illustrating the optical device of this embodiment.

[0060] Figure 4 This is a diagram illustrating the optical device of this embodiment.

[0061] Figure 5 This is a diagram illustrating the optical device of this embodiment.

[0062] Figure 6 This is a diagram illustrating the optical device of this embodiment.

[0063] Figure 7 This is a diagram illustrating the optical device of this embodiment.

[0064] Figure 8 This is a diagram illustrating the optical device of this embodiment.

[0065] Figure 9 This is a diagram representing the first example of a wavelength conversion unit.

[0066] Figure 10 This is a diagram representing the second example of a wavelength conversion unit.

[0067] Figure 11 This is a diagram illustrating the optical device of this embodiment.

[0068] Figure 12is a view showing an optical device of the present embodiment.

[0069] Figure 13 is a view showing an optical device of the present embodiment.

[0070] Figure 14 is a view showing an optical device of the present embodiment.

[0071] Figure 15 is a view showing an optical device of the present embodiment.

[0072] Figure 16 is a view showing an optical device of the present embodiment.

[0073] Figure 17 is a view showing an optical device of the present embodiment.

[0074] Figure 18 is a view showing an optical device of the present embodiment.

[0075] Figure 19 is a view showing an optical device of the present embodiment.

[0076] Figure 20 is a view showing a wireless endoscope. DETAILED DESCRIPTION

[0077] Before the embodiments are explained, effects of an embodiment of one aspect of the present application are described. In addition, when the effects of the present embodiment are specifically described, specific examples are shown to explain. However, as in the case of the embodiments described later, these example aspects are ultimately only a part of the aspects encompassed by the present application, in which there are a large number of variations. Thus, the present application is not limited to the example aspects.

[0078] (Optical device 1 of the present embodiment)

[0079] The optical device of the present embodiment is an optical device having a holding portion and a tubular portion, characterized in that the optical device further has a light source, a light guide member formed of a medium having a refractive index greater than 1, and a light conversion member, the holding portion is located at a position closer to the light source than the tubular portion, light emitted from the light source is incident on an incident end surface of the light guide member, light emitted from an emission end surface of the light guide member is radiated to the light conversion member, the light guide member includes a first light guide region having the incident end surface and a second light guide region having the emission end surface, the diameter of the incident end surface is greater than the diameter of the emission end surface, and at least a part of the second light guide region is included in the tubular portion.

[0080] The drawings used in the following description include drawings in which only a light guide member is depicted. The light guide member is a member that propagates light. Light can be propagated, for example, by using an optical fiber as the light guide member. The optical fiber has a core and a cladding. Since light propagates in the core, the core corresponds to the light guide member. Thus, in each drawing, only the core can be considered to be illustrated.

[0081] Figure 1 is a drawing that represents an optical device of the present embodiment. Figure 1 (a) of is a drawing that represents the appearance of the first example of the optical device. Figure 1 (b) of is a drawing that represents the appearance of the second example of the optical device.

[0082] The optical device of the first example is a flexible endoscope. As shown in (a) of Figure 1 The optical device 1 has a holding portion 2 and a tubular portion 3. The tubular portion 3 is a flexible tubular portion. The optical device 1 has an image pickup element. In the optical device 1, image data acquired by the image pickup element is transmitted to a processing device (not shown) in a wireless manner. Thus, the optical device 1 is a wireless endoscope.

[0083] The optical device of the second example is a rigid endoscope. As shown in (b) of Figure 1 The optical device 4 has a holding portion 5, a tubular portion 6, and a light source unit 7. The tubular portion 6 is a rigid tubular portion. In the optical device 4, an image pickup device is connected. In the optical device 4, image data acquired by the image pickup device is transmitted to a processing device 8 in a wired manner. Thus, the optical device 1 is a non-wireless endoscope.

[0084] In the processing device 8, image processing is performed as necessary. A display device 9 is connected to the processing device 8. In the display device 9, an image acquired by the image pickup element or an image subjected to image processing is displayed.

[0085] The optical device 1 and the optical device 4 each have a light source, a light guide member, and a light conversion member. The configuration of the light source, the light guide member, and the light conversion member will be described.

[0086] Figure 2 is a drawing that represents an optical device of the present embodiment. Figure 2 (a) of is a drawing that represents the first example of the internal structure of the optical device. Figure 2 (b) of is a drawing that represents the second example of the internal structure of the optical device.

[0087] The light conversion member has a wavelength conversion function, a light diffusion function, or both the wavelength conversion function and the light diffusion function. As the light conversion member, a wavelength conversion member, a diffusion member, or both the wavelength conversion member and the diffusion member can be used.

[0088] In the first example, a wavelength conversion member is used as the light conversion member. In the second example, a diffusion member is used as the light conversion member.

[0089] In the first example, as shown in (a) of FIG. 1, the optical device 10 has a light source 11, a light guide member 12, and a wavelength conversion member 13. The light guide member 12 is formed of a medium having a refractive index greater than 1. In the light guide member 12, a single medium is formed from the incident end face 12a to the exit end face 12b. Figure 2

[0090] The light Ll of the first wavelength region is emitted from the light source 11. The light Ll of the first wavelength region reaches the light guide member 12. A lens can be disposed, for example, between the light source 11 and the light guide member 12. By disposing the lens, the light Ll of the first wavelength region can be efficiently incident on the light guide member 12.

[0091] The light guide member 12 has a first light guide region 12' and a second light guide region 12". The first light guide region 12' has the incident end face 12a. The second light guide region 12" has the exit end face 12b.

[0092] The shape of the first light guide region 12' is a circular truncated cone. The first light guide region 12' is formed so that the apex of the cone is on the side of the second light guide region 12". The shape of the second light guide region 12" is a circular cylinder. In addition, it is not limited thereto, and can be a truncated pyramid and a prism, but is most preferably the aforementioned circular truncated cone and circular cylinder.

[0093] The light Ll of the first wavelength region is incident on the first light guide region 12' through the incident end face 12a. In the first light guide region 12', the light Ll of the first wavelength region travels from the incident end face 12a toward the second light guide region 12".

[0094] As described above, the light guide member 12 is formed of a medium having a refractive index greater than 1. Thus, in the first light guide region 12', a part of the light Ll of the first wavelength region reaches the second light guide region 12" while being repeatedly totally reflected by the side surface of the circular truncated cone.

[0095] In the second light guide region 12", the light Ll of the first wavelength region travels from the first light guide region 12' toward the exit end face 12b.

[0096] As described above, the light guide member 12 is formed of a medium having a refractive index greater than 1. Thus, in the second light guide region 12", a part of the light Ll of the first wavelength region travels toward the exit end face 12b while being repeatedly totally reflected by the side surface of the circular cylinder.

[0097] The light Ll of the first wavelength region that reaches the exit end face 12b is emitted from the exit end face 12b. As a result, the light Ll of the first wavelength region is irradiated on the wavelength conversion member 13.

[0098] ​A part of the light in the light L1 of the first wavelength region is transmitted through the wavelength conversion member 13. The light transmitted through the wavelength conversion member 13 is not subjected to wavelength conversion by the wavelength conversion member 13. Thus, the light L1 of the first wavelength region is emitted from the wavelength conversion member 13.

[0099] The remaining light in the light L1 of the first wavelength region is subjected to wavelength conversion by the wavelength conversion member 13. That is, the light L2 of the second wavelength region is generated from the light L1 of the first wavelength region by the wavelength conversion member 13. The light of the second wavelength region includes light having a longer wavelength than the light of the first wavelength region.

[0100] Thus, the light L1 of the first wavelength region and the light L2 of the second wavelength region are emitted from the wavelength conversion member 13. Thus, in the optical device 10, the light L1 of the first wavelength region and the light L2 of the second wavelength region can be used for illumination.

[0101] As described above, in the optical device 10, the shape of the first light guide region 12' is a circular truncated cone. In the circular truncated cone, the apex of the cone is located on the side of the second light guide region 12".

[0102] When the bottom surface of the circular truncated cone is set as the incident end surface 12a, the bottom surface of the circular truncated cone is located on the side of the light source 11, and the upper surface of the circular truncated cone is located on the side of the second light guide region 12". In the circular truncated cone, the diameter of the bottom surface is larger than the diameter of the upper surface. Thus, in the first light guide region 12', the diameter gradually decreases from the incident end surface 12a toward the second light guide region 12".

[0103] The shape of the second light guide region 12" is a circular cylinder. Thus, in the second light guide region 12", the diameter does not change.

[0104] The diameter of the upper surface of the circular truncated cone is equal to the diameter of the second light guide region 12". The diameter of the second light guide region 12" is equal to the diameter of the exit end surface 12b. As described above, in the circular truncated cone, the diameter of the bottom surface is larger than the diameter of the upper surface. Thus, the diameter of the incident end surface 12a is larger than the diameter of the exit end surface 12b.

[0105] In the light guide member 12, the incident end surface 12a is located on the side of the light source 11. The diameter of the incident end surface 12a is the largest diameter in the light guide member 12. Therefore, the light L1 of the first wavelength region emitted from the light source 11 can be efficiently caused to be incident on the incident end surface 12a.

[0106] As described above, in the light guide member 12, the incident end surface 12a is formed to the exit end surface 12b by a single medium. In this case, no physical boundary is formed between the incident end surface 12a and the exit end surface 12b. Thus, in the light guide member 12, the light L1 of the first wavelength region incident on the first light guide region 12' can be efficiently caused to be incident on the second light guide region 12".

[0107] The light L1 of the first wavelength region incident to the second light guide region 12" is irradiated to the wavelength conversion member 13. In this case, since bright light can be irradiated to the wavelength conversion member 13, the brightness of the light L2 of the second wavelength region which is emitted from the wavelength conversion member 13 can be made bright. Thus, bright illumination light can be obtained.

[0108] The diameter of the second light guide region 12" is smaller than the diameter of the incident end face 12a. In the light guide member 12, the diameter of the cylinder can be made very small. Therefore, the second light guide region 12" can be made flexible.

[0109] In the optical device 10, the length of the first light guide region 12' is shorter than the length of the second light guide region 12". Further, at least a part of the second light guide region 12" is included in the tubular portion.

[0110] As described above, the diameter of the second light guide region 12" is very small. By including at least a part of the second light guide region 12" in the tubular portion, the thickness of the tubular portion 3 in the optical device 1 can be made thin, and the thickness of the tubular portion 6 in the optical device 4 can be made thin.

[0111] At least a part of the tubular portion 3 is inserted into, for example, a body or a metal pipe. Since the thickness of the tubular portion 3 is thin, the tubular portion 3 can be easily inserted into the body or the metal pipe. Further, in the optical device 1, the tubular portion 3 can be easily bent.

[0112] At least a part of the tubular portion 6 is inserted into, for example, a body or a metal pipe. Since the thickness of the tubular portion 6 is thin, the tubular portion 6 can be easily inserted into the body or the metal pipe.

[0113] In the wavelength conversion member 13, the surface can be made a scattering surface. Further, the wavelength conversion member 13 can contain fine particles. By doing so, the light L1 of the first wavelength region and the light L2 of the second wavelength region can be diffused.

[0114] As the light guide member 12, for example, a tapered optical fiber can be used. The tapered optical fiber can be manufactured by performing stretching while over-heating an optical fiber parent material. In the tapered optical fiber, the diameter of the incident end face is different from the diameter of the emission end face.

[0115] In the tapered optical fiber, the outer diameter is made smaller from the incident end face toward the emission end face. The outer diameter can be gradually made smaller, or can be made smaller in stages.

[0116] In the second example, as Figure 2As shown in (b), the optical device 14 has the light source 11, the light guide member 15, and the diffusion member 16. The light guide member 15 is formed of a medium having a refractive index greater than 1. In the light guide member 15, from the incident end face 17a to the exit end face 18b, by two media.

[0117] The light guide member 15 is formed of the light guide member 17 and the light guide member 18. The first light guide member 17 has the incident end face 17a and the exit end face 17b. The second light guide member 18 has the incident end face 18a and the exit end face 18b.

[0118] The light guide member 17 and the light guide member 18 are connected, for example, with optical contact. In the optical contact, a joint face is formed by the exit end face 17b and the incident end face 18a. The light guide member 17 and the light guide member 18 can also be connected using a bonding agent.

[0119] The light guide member 15 has the first light guide region 15' and the second light guide region 15". The first light guide region 15' is formed of the light guide member 17. The second light guide region 15" is formed of the light guide member 18. The first light guide region 15' has the incident end face 17a. The second light guide region 15" has the exit end face 18b.

[0120] The shape of the light guide member 17, that is, the shape of the first light guide region 15' is a circular truncated cone. The first light guide region 15' is formed so that the apex of the cone is on the side of the second light guide region 15". The shape of the light guide member 18, that is, the shape of the second light guide region 15" is a circular cylinder.

[0121] The light L1 of the first wavelength region exits from the light source 11. The light L1 of the first wavelength region is incident on the first light guide region 15' through the incident end face 17a. In the first light guide region 15', the light L1 of the first wavelength region travels from the incident end face 17a toward the exit end face 17b.

[0122] The light guide member 17 is formed of a medium having a refractive index greater than 1. Thus, in the first light guide region 15', a part of the light L1 of the first wavelength region reaches the second light guide region 15" while being repeatedly totally reflected by the side face of the circular truncated cone.

[0123] The light L1 of the first wavelength region is incident on the second light guide region 15" through the incident end face 18a. In the second light guide region 15", the light L1 of the first wavelength region travels from the incident end face 18a toward the exit end face 18b.

[0124] The light guide member 18 is formed of a medium having a refractive index greater than 1. Thus, in the second light guide region 15", a part of the light L1 of the first wavelength region travels toward the exit end face 18b while being repeatedly totally reflected by the side face of the circular cylinder.

[0125] The light Ll of the first wavelength range that has reached the exit end surface 18b exits from the exit end surface 18b. As a result, the light Ll of the first wavelength range is irradiated toward the diffusion member 16.

[0126] The diffusion member 16 is formed of, for example, a transparent medium having a diffusion surface or a transparent medium containing fine particles. The light Ll of the first wavelength range is diffused by the diffusion surface or the fine particles. Thus, in the optical device 14, the light Ll of the first wavelength range that has been diffused can be used for illumination.

[0127] In the light guide member 15, the incident end surface 17a is located on the light source 11 side. The diameter of the incident end surface 17a is the largest diameter in the light guide member 15. Thus, the light Ll of the first wavelength range that has exited from the light source 11 can be efficiently incident on the incident end surface 17a.

[0128] As described above, in the light guide member 15, two mediums are formed from the incident end surface 17a to the exit end surface 18b. Thus, a physical boundary, such as a joint surface formed by optical cement or a joint surface formed by an adhesive, is formed between the incident end surface 17a and the exit end surface 18b.

[0129] However, the boundary hardly affects the light. Thus, in the light guide member 15, the light Ll of the first wavelength range that has been incident on the first light guide region 15' can be efficiently incident on the second light guide region 15".

[0130] The light Ll of the first wavelength range that has been incident on the second light guide region 15" is irradiated toward the diffusion member 16. In this case, since bright light can be irradiated toward the diffusion member 16, the brightness of the light Ll of the first wavelength range that has exited from the diffusion member 16 can be made brighter. Thus, bright illumination light can be obtained.

[0131] In the optical device 14, the length of the first light guide region 15' is shorter than the length of the second light guide region 15". Further, at least a part of the second light guide region 15" is contained in the tubular portion.

[0132] As described above, the diameter of the second light guide region 15" is very small. By containing at least a part of the second light guide region 15" in the tubular portion, the thickness of the tubular portion 3 in the optical device 1 can be made thinner, and the thickness of the tubular portion 6 in the optical device 4 can be made thinner.

[0133] In the optical device 10, the diffusion member 16 can be disposed beside the wavelength conversion member 13. In the optical device 14, the wavelength conversion member 13 can be disposed beside the diffusion member 16.

[0134] In the optical device 1, the optical device 4, the optical device 10, and the optical device 14, light emitted from the light source can be efficiently irradiated to the light conversion member. Thus, in these optical devices, a higher light use efficiency can be obtained.

[0135] In the wireless endoscope such as the optical device 1, a power source is arranged in the optical device 1. Thus, it is preferable that the optical device 1 be operated with less power. In particular, it is preferable that the power supplied to the light source be less.

[0136] As described above, in the optical device 1, the light use efficiency is high, and thus the loss of illumination light is less. Thus, the power supplied to the light source can be reduced. As a result, the generation of heat can be suppressed. Further, even if heat is generated, a heat dissipation mechanism can be reduced. Thus, the optical device 1 can be made compact.

[0137] Hereinafter, a preferable embodiment of the optical device will be described. As described above, in the optical device of the present embodiment, the light conversion member can use the wavelength conversion member, the diffusion member, or both the wavelength conversion member and the diffusion member. Hereinafter, a case where the light conversion member uses the wavelength conversion member will be described.

[0138] The optical device of the present embodiment can be used as an illumination device or an illumination unit.

[0139] (Optical device 2 of the present embodiment)

[0140] In the optical device of the present embodiment, it is preferable that the holding portion have an outer circumference larger than the largest outer circumference of the tubular portion, the tubular portion have a front end portion and a base end portion, the light conversion member be arranged at the front end portion, the holding portion be located at the base end portion side, and the first light guide region be located as a whole at a position closer to the holding portion than the tubular portion.

[0141] Figure 3 is a view that shows the optical device of the present embodiment. The same components as those of (a) of Figure 2 The same components as those of (a) of

[0142] The optical device 20 is a wireless endoscope. The optical device 20 has a holding portion 21 and a tubular portion 22. The tubular portion 22 is a soft tubular portion. The holding portion 21 has an outer circumference larger than the largest outer circumference of the tubular portion 22. In the optical device 20, the second light guide region 12” is contained as a whole in the tubular portion 22.

[0143] The tubular portion 22 has a front end portion 23 and a base end portion 24. The wavelength conversion member 13 is located at the front end portion 23. The holding portion 21 is located at the base end portion 24 side. The first light guide region 12’ is located as a whole at a position closer to the holding portion 21 than the tubular portion 22.

[0144] In the optical device 20, the light source 11 is disposed in the holding portion 21. The holding portion 21 has an operation portion 25. Further, an intermediate portion 26 is provided between the holding portion 21 and the tubular portion 22. A breakage-preventing portion that prevents longitudinal bending of the opening portion for insertion of the treatment instrument or the tubular portion 22 can be provided in the intermediate portion 26.

[0145] The tubular portion 22 is occupied by the second light guide region 12". The diameter of the second light guide region 12" is very small. Therefore, in the optical device 20, the thickness of the tubular portion 22 can be made thin. At least a part of the tubular portion 22 is inserted into, for example, a body or a metal pipe. Thus, the tubular portion 22 can be easily inserted.

[0146] Further, the first light guide region 12' is located between the light source 11 and the second light guide region 12". Therefore, the first wavelength region light L1 emitted from the light source 11 can be efficiently incident on the first light guide region 12'.

[0147] Further, the first wavelength region light L1 can efficiently travel from the first light guide region 12' to the second light guide region 12". In this case, since bright light can be irradiated to the wavelength conversion member 13, bright illumination light can be obtained.

[0148] As described above, the holding portion 21 has an outer circumference larger than the maximum outer circumference of the tubular portion 22. Thus, the holding portion 21 and the tubular portion 22 can be distinguished from each other according to the difference in the size of the outer circumference.

[0149] The first light guide region 12' is located on the holding portion 21 side from the tubular portion 22. Therefore, a space in which the first light guide region 12' can be located is ensured on the holding portion 21 side from the tubular portion 22. The outer circumference of the holding portion 21 can be set so as to include the space.

[0150] Alternatively, in a case where the incident end face 12a, the cross section of the tubular portion 22, and the cross section of the holding portion 21 are coincident with each other, the incident end face 12a can be included in the cross section of the holding portion 21.

[0151] Figure 4 is a view that shows the optical device of the present embodiment. The same structures as those of (a) of Figure 2 The same structures as those of (a) of the optical device 20 are denoted by the same reference numerals, and the description thereof is omitted.

[0152] The optical device 30 is a wireless endoscope. The optical device 30 has a holding portion 31 and a tubular portion 32. The tubular portion 32 is a soft tubular portion. The holding portion 31 has an outer circumference larger than the maximum outer circumference of the tubular portion 32. In the optical device 30, a part of the second light guide region 12" is included in the tubular portion 32.

[0153] The tubular portion 32 has a front end portion 33 and a base end portion 34. The wavelength conversion member 13 is located at the front end portion 33. The holding portion 31 is located at the base end portion 34 side. The first light guide region 12' is located as a whole at a position closer to the holding portion 31 than the tubular portion 32.

[0154] In the optical device 30, the light source 11 is arranged at the holding portion 31. The holding portion 31 has an operation portion 35. Further, an intermediate portion 36 is provided between the holding portion 31 and the tubular portion 32. In the optical device 30, the second light guide region 12" is also included in the intermediate portion 36.

[0155] The tubular portion 32 is occupied by the second light guide region 12". The diameter of the second light guide region 12" is very small. Therefore, in the optical device 30, the thickness of the tubular portion 32 can be made thin. At least a part of the tubular portion 32 is inserted, for example, into the body or into a metal tube. Thus, the tubular portion 32 can be easily inserted.

[0156] Further, the first light guide region 12' is located between the light source 11 and the second light guide region 12". Therefore, the light L1 of the first wavelength region emitted from the light source 11 can be efficiently incident on the first light guide region 12'.

[0157] Further, the light L1 of the first wavelength region can be efficiently propagated from the first light guide region 12' to the second light guide region 12". In this case, since bright light can be irradiated to the wavelength conversion member 13, bright illumination light can be obtained.

[0158] Further, the intermediate portion 36 is also occupied by the second light guide region 12". Thus, the thickness of the intermediate portion 36 can be made the same as the thickness of the tubular portion 32. That is, the thickness of the intermediate portion 36 can be made thin. As a result, at least a part of the intermediate portion 36 can be inserted, for example, into the body or into a metal tube.

[0159] The intermediate portion 36 can be made into a hard tubular portion. In a case where the length of the intermediate portion 36 is very long compared to the length of the tubular portion 32, the optical device 30 can be regarded as a rigid endoscope. In a case where the length of the intermediate portion 36 is very short compared to the length of the tubular portion 32, the optical device 30 can be regarded as a flexible endoscope.

[0160] Figure 5 is a view showing the optical device of the present embodiment. The same structures as those of (a) of Figure 2 The same structures as those of (a) of

[0161] The optical device 40 is a wireless endoscope. The optical device 40 has a holding portion 41 and a tubular portion 42. The tubular portion 42 is a hard tubular portion. The holding portion 41 has an outer circumference larger than the largest outer circumference of the tubular portion 42. In the optical device 40, the second light guide region 12" is included as a whole in the tubular portion 42.

[0162] The tubular portion 42 has a front end portion 43 and a base end portion 44. The wavelength conversion member 13 is located at the front end portion 43. The holding portion 41 is located at the base end portion 44 side. The first light guide region 12' is located as a whole at a position closer to the holding portion 41 than the tubular portion 42.

[0163] In the optical device 40, the light source 11 is arranged at the holding portion 41. The holding portion 41 has a connecting portion. The imaging device 45 can be attached to the holding portion 41 by means of the connecting portion. The imaging device 45 has an imaging element. In the imaging device 45, the acquired image data is transmitted to the processing device in a wireless manner. As the imaging device 45, a wired type imaging device can also be used. In this case, the optical device 40 becomes a non-wireless endoscope.

[0164] In the optical device 40, the holding portion 41 and the tubular portion 42 are directly connected. However, an intermediate portion can be provided between the holding portion 41 and the tubular portion 42 or a part of the holding portion 41 can be provided as an intermediate portion. An opening portion for insertion of a treatment instrument can be provided at the intermediate portion.

[0165] The tubular portion 42 is occupied by the second light guide region 12". The diameter of the second light guide region 12" is very small. Therefore, in the optical device 40, the thickness of the tubular portion 42 can be made thin. At least a part of the tubular portion 42 is inserted, for example, into a body or a metal tube. Thus, the tubular portion 42 can be easily inserted.

[0166] Further, the first light guide region 12' is located between the light source 11 and the second light guide region 12". Therefore, the light L1 of the first wavelength region emitted from the light source 11 can be efficiently incident on the first light guide region 12'.

[0167] Further, the light L1 of the first wavelength region can be efficiently traveled from the first light guide region 12' to the second light guide region 12". In this case, since bright light can be irradiated to the wavelength conversion member 13, bright illumination light can be obtained.

[0168] (Optical device 3 of the present embodiment)

[0169] In the optical device of the present embodiment, it is preferable that the holding portion have an outer circumference larger than the largest outer circumference of the tubular portion, the second light guide region be contained as a whole in the tubular portion, the tubular portion have a front end portion and a base end portion, the light conversion member be arranged at the front end portion, the holding portion be located at the base end portion side, and at least a part of the first light guide region be contained in the tubular portion.

[0170] Figure 6 is a view that shows the optical device of the present embodiment. The same structure as (a) of Figure 2 The same reference numerals are attached to the same structures as (a) of

[0171] The optical device 50 is a wireless endoscope. The optical device 50 has a holding portion 51 and a tubular portion 52. The tubular portion 52 is a hard tubular portion. The holding portion 51 has an outer circumference larger than a maximum outer circumference of the tubular portion 52. In the optical device 50, the second light guide region 12" is entirely contained in the tubular portion 52.

[0172] The tubular portion 52 has a front end portion 53 and a base end portion 54. The wavelength conversion member 13 is located at the front end portion 53. The holding portion 51 is located at the base end portion 54 side. The first light guide region 12' is entirely contained in the tubular portion 52.

[0173] In the optical device 50, the light source 11 is arranged at the holding portion 51. The holding portion 51 and the tubular portion 52 are directly connected. However, an intermediate portion can be provided between the holding portion 51 and the tubular portion 52 or a part of the holding portion 51 can be provided as the intermediate portion. An opening portion for insertion of a treatment instrument can be provided at the intermediate portion.

[0174] At least a part of the tubular portion 52 is inserted into, for example, a body or a metal pipe. As described above, in the optical device 50, the first light guide region 12' is entirely contained and the second light guide region 12" is entirely contained in the tubular portion 52. Therefore, for example, compared with the optical device 40, the thickness of the tubular portion 52 is slightly thick.

[0175] However, in a metal pipe or the like having a large diameter, the tubular portion 52 can be inserted without any problem. Further, compared with a case where the first light guide region 12' is entirely located at the holding portion 51, the length of the holding portion 51 can be shortened.

[0176] Further, the first light guide region 12' is located between the light source 11 and the second light guide region 12". Therefore, the light L1 of the first wavelength region emitted from the light source 11 can be efficiently incident on the first light guide region 12'.

[0177] Further, the light L1 of the first wavelength region can be efficiently traveled from the first light guide region 12' to the second light guide region 12". In this case, since bright light can be irradiated to the wavelength conversion member 13, bright illumination light can be obtained.

[0178] Figure 7 is a view showing the optical device of the present embodiment. The same structures as those of (a) of Figure 2 The same structures as those of (a) of

[0179] The optical device 60 is a wireless endoscope. The optical device 60 has a holding portion 61 and a tubular portion 62. The tubular portion 62 is a hard tubular portion. The holding portion 61 has an outer circumference larger than a maximum outer circumference of the tubular portion 62. In the optical device 60, the second light guide region 12" is entirely contained in the tubular portion 62.

[0180] The tubular portion 62 has a front end portion 63 and a base end portion 64. The wavelength conversion member 13 is located at the front end portion 63. The holding portion 61 is located at the base end portion 64 side. A part of the first light guide region 12' is included in the tubular portion 62.

[0181] In the optical device 60, the light source 11 is arranged at the holding portion 61. The holding portion 61 and the tubular portion 62 are directly connected. However, an intermediate portion can be provided between the holding portion 61 and the tubular portion 62 or a part of the holding portion 61 can be provided as the intermediate portion. An opening portion for insertion of a treatment instrument can be provided at the intermediate portion.

[0182] At least a part of the tubular portion 62 is inserted into, for example, a body or a metal pipe. As described above, in the optical device 60, a part of the first light guide region 12' and the second light guide region 12" are integrally included in the tubular portion 62. Therefore, for example, compared with the optical device 40, the thickness of the tubular portion 62 is slightly thick.

[0183] However, in a metal pipe or the like having a large diameter, the tubular portion 62 can be inserted without problems. Further, compared with a case where the first light guide region 12' is located at the holding portion 61 as a whole, the length of the holding portion 61 can be shortened.

[0184] Further, the first light guide region 12' is located between the light source 11 and the second light guide region 12". Therefore, the light L1 of the first wavelength region emitted from the light source 11 can be efficiently incident on the first light guide region 12'.

[0185] Further, the light L1 of the first wavelength region can be efficiently propagated from the first light guide region 12' to the second light guide region 12". In this case, since bright light can be irradiated to the wavelength conversion member 13, bright illumination light can be obtained.

[0186] (Optical device 4 of the present embodiment)

[0187] In the optical device of the present embodiment, it is preferable that the tubular portion is formed of a first tubular portion and a second tubular portion, the first tubular portion has a first front end portion and a first base end portion, the second tubular portion has a second front end portion and a second base end portion, the light conversion member is arranged at the first front end portion, the holding portion is located between the first base end portion and the second front end portion, the connecting portion is located at the second base end portion side, the second light guide region is integrally included in the tubular portion, and the first light guide region is located at a position closer to the connecting portion side than the second tubular portion.

[0188] Figure 8 is a view that shows the optical device of the present embodiment. The same structures as those of (a) of Figure 2 The same structures as those of (a) of

[0189] The optical device 70 is a non-wireless endoscope. The optical device 70 has a holding portion 71 and a tubular portion 72. The tubular portion 72 is a soft tubular portion. The tubular portion 72 is formed of a first tubular portion 73 and a second tubular portion 74.

[0190] The first tubular portion 73 has a first front end portion 75 and a first base end portion 76. The second tubular portion 74 has a second front end portion 77 and a second base end portion 78.

[0191] The wavelength conversion member 13 is located at the first front end portion 75. The holding portion 71 is located between the first base end portion 76 and the second front end portion 77. A connecting portion 79 is located at the second base end portion 78 side.

[0192] The light source unit 80 is connected to the connecting portion 79. The light source 11 is provided to the light source unit 80.

[0193] In the optical device 70, the second light guide region 12" is entirely contained in the tubular portion 72. The first light guide region 12' is located at a position closer to the connecting portion 79 than the second tubular portion 74. The first light guide region 12' can be located at the connecting portion 79 or at the light source unit 80.

[0194] The first tubular portion 73 is occupied by the second light guide region 12". The diameter of the second light guide region 12" is very small. Therefore, in the optical device 70, the thickness of the first tubular portion 73 can be made thin. At least a part of the first tubular portion 73 is inserted into the body or a metal tube, for example. Thus, the first tubular portion 73 can be easily inserted.

[0195] Further, the first light guide region 12' is provided between the light source 11 and the second light guide region 12". Therefore, the light L1 of the first wavelength region emitted from the light source 11 can be efficiently incident on the first light guide region 12'.

[0196] Further, the first light guide region 12' is provided between the light source 11 and the second light guide region 12". Therefore, the light L1 of the first wavelength region emitted from the light source 11 can be efficiently incident on the first light guide region 12'.

[0197] Further, the second tubular portion 74 is occupied by the second light guide region 12". The diameter of the second light guide region 12" is very small. Therefore, in the optical device 70, the thickness of the second tubular portion 74 can be made thin. As a result, the handling of the optical device 70 becomes easy.

[0198] (Front end portion of optical device)

[0199] As described above, the optical device of this embodiment can produce bright illumination light. This is because it can efficiently direct light emitted from the light source into the light-guiding member and efficiently propagate the incident light. Furthermore, bright illumination light can be obtained for the following reasons.

[0200] In the following description, light with a peak wavelength of 415 nm will be referred to as "excitation light L". 415 The light with a peak wavelength of 450nm is called the "excitation light L". 450 Light with a peak wavelength of 540nm is called "radioactive light". 540 Light with a peak wavelength of 575nm is called "radioactive light". 575 ".

[0201] In the optical device of this embodiment, a light conversion unit is disposed at the front end of the tubular portion. The light conversion unit has a wavelength conversion member. In this case, the light conversion unit functions as a wavelength conversion unit.

[0202] Figure 9 This is a diagram representing the first example of a wavelength conversion unit. Figure 9 (a) is a diagram showing the case where the diameter of the second light-guiding region 12” is smaller. Figure 9 (b) is a diagram showing the case where the diameter of the second light-guiding region 12” is larger.

[0203] like Figure 9 As shown in (a), the wavelength conversion unit 90 includes a holding member 91, a reflecting member 92, and a wavelength conversion member 93. Furthermore, as... Figure 9 As shown in (b), the wavelength conversion unit 95 has a holding member 96, a reflecting member 97 and a wavelength conversion member 93.

[0204] The structure of wavelength conversion unit 95 is substantially the same as that of wavelength conversion unit 90. Therefore, the description of the structure of wavelength conversion unit 95 is omitted.

[0205] In the wavelength conversion unit 90, a recess is formed at one end of the holding member 91. A reflecting member 92 is disposed in the recess. A reflecting surface is formed on the inner peripheral surface of the recess by means of the reflecting member 92.

[0206] The reflective member 92 is a hollow member. The wavelength conversion member 93 is disposed in the hollow portion. The hollow portion can be filled with, for example, a transparent medium. Thus, the wavelength conversion member 93 can be retained.

[0207] A through hole is formed at the other end of the retaining member 91 facing the recess. A light guide member 94 is inserted into the through hole. In the wavelength conversion unit 95, a light guide member 98 is inserted into the through hole.

[0208] Since the recess is shaped like a truncated cone, the reflector 92 has the same shape as the side surface of the truncated cone. In the recess, the diameter of one end is smaller than the diameter of the other end. Therefore, in the reflector 92, the diameter of one end (hereinafter referred to as the "incident end face Ri") is smaller than the diameter of the other end (hereinafter referred to as the "outcryogenic end face Ro").

[0209] The incident end face Ri is located on the through hole side. The diameter of the incident end face Ri is the same as the diameter of the through hole, that is, the diameter of the second light guiding region of the light guide component 94.

[0210] like Figure 2 As shown in (a), light L1 in the first wavelength domain is emitted from the light source 11. Light L1 in the first wavelength domain is emitted from the light guide member 12. Figure 9 In (a), light L1 in the first wavelength domain is emitted from the light guide member 94. The light L1 in the first wavelength domain illuminates the wavelength conversion member 93. The wavelength conversion member 93 uses a phosphor. In the phosphor, light L2 in the second wavelength domain with a wavelength longer than the illuminated light is generated.

[0211] As a phosphor, YAG:Ce phosphors (hereinafter referred to as "YAG phosphors") can be used. YAG phosphors have the advantage of using Y3A... l5 O 12 The components are represented. The excitation light L1, representing the first wavelength region, is used to irradiate the YAG phosphor. 450 At that time, the YAG phosphor generates emitted light L2, which is the light in the second wavelength domain. 575 .

[0212] However, a portion of the irradiated light passes through the YAG phosphor. Therefore, excitation light L is emitted from the wavelength conversion element 93. 450 and radiation L 575 Excitation light L 450 It is blue light, radiating light L 575 It is yellow light. Therefore, the light emitted from the exit face Ro is approximately white.

[0213] Excitation light L irradiated onto wavelength conversion component 93 450 A portion of it is reflected by wavelength conversion component 93. In wavelength conversion unit 90, the reflected excitation light L... 450 A portion of it travels towards the light guide component 94. In the wavelength conversion unit 95, the reflected excitation light L... 450 A portion of it travels toward the guide light component 98.

[0214] Radiated light L 575 It is fluorescence. Fluorescence travels in all directions. Therefore, in wavelength conversion unit 90, the emitted light L... 575A portion of it travels towards the light guide component 94. In the wavelength conversion unit 95, the emitted light L... 575 A portion of it travels toward the guide light component 98.

[0215] exist Figure 9 In (a), the excitation light L incident on the guide light component 94 450 and radiation L 575 (Hereinafter referred to as "Light Beams (LBS)") are indicated by dashed arrows. Figure 9 In (b), the excitation light L incident on the guide light component 98 450 and radiation L 575 (Hereinafter referred to as "beam LBL") is indicated by a solid arrow.

[0216] Because beam LBS is incident on guide member 94, it does not exit from exit face Ro. Similarly, because beam LBL is incident on guide member 98, it also does not exit from exit face Ro. Therefore, neither beam LBS nor beam LBL can be used as illumination light. The size of the arrow indicates the size of the beam not used as illumination light.

[0217] As described above, the diameter of the second light-guiding region of the light guide member 94 is smaller than the diameter of the second light-guiding region of the light guide member 98. Therefore, the size of the dashed arrow is smaller than the size of the solid arrow. That is, the size of the light beam LBS is smaller than the size of the light beam LBL. Therefore, in the wavelength conversion unit 90, the amount of light incident on the light guide member can be reduced compared to the wavelength conversion unit 95. As a result, in the wavelength conversion unit 90, the loss of illumination light can be reduced compared to the wavelength conversion unit 95.

[0218] The wavelength conversion member 93 can be made to have a diffusion effect. For example, a diffusion effect can be obtained by providing a diffusion surface in the wavelength conversion member 93 or by containing fine particles in the wavelength conversion member 93. When the wavelength conversion member 93 has a diffusion effect, excitation light L is generated. 450 Scattered and emitted light L 575 Scattered light (hereinafter referred to as "scattered light L") BY ”).

[0219] Scattered light L BY It travels in all directions. Therefore, in wavelength conversion unit 90, the scattered light L BY A portion of it travels towards the light guide component 94. In the wavelength conversion unit 95, it is also the scattered light L... BY A portion of it travels toward the light guide component 98. Therefore, the beam LBS and beam LBL each contain scattered light L... BY Part of it.

[0220] A diffusing member can be used instead of the wavelength converting member 93. In this case, the wavelength converting unit functions as a light diffusing unit. Although fluorescent light is not generated in the diffusing member, scattered light is generated. The scattered light travels in all directions. Therefore, in the wavelength converting unit 90, a portion of the scattered light travels toward the light guide member 94. In the wavelength converting unit 95, also a portion of the scattered light travels toward the light guide member 98. Thus, when the diffusing member is used, a portion of the scattered light is included in the light beam LBS and the light beam LBL, respectively.

[0221] As described above, the size of the light beam LBS is smaller than the size of the light beam LBL. Thus, in the wavelength converting unit 90, the light incident on the light guide member can be reduced compared to the wavelength converting unit 95. As a result, in the wavelength converting unit 90, the loss of the illumination light can be reduced compared to the wavelength converting unit 95.

[0222] Further, a reflecting surface is formed on the inner circumferential surface of the recess. The larger the area of the reflecting surface, the larger the proportion of the light Ll of the first wavelength region and the light L2 of the second wavelength region that travel toward the exit end surface Ro. As Figure 9 As shown in (b) of FIG. 10, in the wavelength converting unit 95, the reflecting surface is not present in the range Dl, in contrast, in the wavelength converting unit 90, the reflecting surface is present at a position corresponding to the range Dl. Thus, in the wavelength converting unit 90, the proportion of the light L2 of the second wavelength region that travels toward the exit end surface Ro can be increased compared to the wavelength converting unit 95.

[0223] In the optical device of the present embodiment, the first light guide region is disposed at a position closer to the holding portion than the second light guide region. Thus, the diameter of the second light guide region can be made very small. In this case, the proportion of the light L2 of the second wavelength region that is incident on the second light guide region can be reduced, and further, the proportion of the light L2 of the second wavelength region that travels toward the exit end surface Ro can be increased. As a result, in the optical device of the present embodiment, bright illumination light can be obtained.

[0224] Figure 10 FIG. 11 is a view showing a second example of a wavelength converting unit. Figure 10 (a) of FIG. 12 is a view showing a case where the diameter of the second light guide region 12" is small. Figure 10 (b) of FIG. 12 is a view showing a case where the diameter of the second light guide region 12" is large.

[0225] As shown in (a) of FIG. 13, the wavelength converting unit 100 has a holding member 101, a reflecting member 102, and a wavelength converting member 103. Further, as shown in (b) of FIG. 13, the wavelength converting unit 105 has a holding member 106, a reflecting member 107, and the wavelength converting member 103. Figure 10 As shown in (a) of FIG. 13, the wavelength converting unit 100 has a holding member 101, a reflecting member 102, and a wavelength converting member 103. Further, as shown in (b) of FIG. 13, the wavelength converting unit 105 has a holding member 106, a reflecting member 107, and the wavelength converting member 103. Figure 10 As shown in (a) of FIG. 13, the wavelength converting unit 100 has a holding member 101, a reflecting member 102, and a wavelength converting member 103. Further, as shown in (b) of FIG. 13, the wavelength converting unit 105 has a holding member 106, a reflecting member 107, and the wavelength converting member 103.

[0226] The structure of wavelength conversion unit 105 is substantially the same as that of wavelength conversion unit 100. Therefore, the description of the structure of wavelength conversion unit 105 is omitted.

[0227] In the wavelength conversion unit 100, a recess is formed at one end of the holding member 101. A reflecting member 102 is disposed in the recess. A reflecting surface is formed on the inner peripheral surface of the recess by means of the reflecting member 102.

[0228] The reflective member 102 is a hollow member. The wavelength conversion member 103 is disposed in the hollow portion. The hollow portion can be filled with, for example, a transparent medium. Thus, the wavelength conversion member 103 can be retained.

[0229] A through hole is formed at the other end of the retaining member 101 facing the recess. A light guide member 104 is inserted into the through hole. In the wavelength conversion unit 105, a light guide member 108 is inserted into the through hole.

[0230] Since the recess is shaped like a truncated cone, the reflective member 102 has the same shape as the side surface of the truncated cone. In the recess, the diameter of one end is smaller than the diameter of the other end. Therefore, in the reflective member 102, the diameter of the incident end face Ri is smaller than the diameter of the exit end face Ro.

[0231] The incident end face Ri is located on the through hole side. The diameter of the incident end face Ri is larger than the diameter of the through hole, that is, the diameter of the second light guiding region of the light guide member 104. Therefore, an annular reflective surface 102a is formed on the incident end face Ri of the reflective member 102. The light guide member 104 is located on the inner edge side of the reflective surface 102a.

[0232] exist Figure 10 In (a), light L1 in the first wavelength domain is emitted from the light guide member 104. The light L1 in the first wavelength domain illuminates the wavelength conversion member 103. The wavelength conversion member 103 uses a phosphor. In the phosphor, light L2 in the second wavelength domain with a wavelength longer than the illuminated light is generated.

[0233] As a phosphor, a silon-based phosphor activated by Eu (europium) can be used (hereinafter referred to as "silon phosphor"). When the silon phosphor is irradiated with excitation light L1, which is light in the first wavelength domain... 415 At that time, the silon phosphor produces emitted light L2, which is the second wavelength domain light. 540 .

[0234] However, a portion of the irradiated light passes through the silon phosphor. Therefore, excitation light L is emitted from the wavelength conversion element 93. 415 and radiation L 540 Excitation light L 415 It is blue-violet light, radiating light L 540is green. Thus, light approximately close to blue-green is emitted from the exit end surface Ro.

[0235] A part of the excitation light L 415 irradiated to the wavelength conversion member 103 is reflected by the wavelength conversion member 103. In the wavelength conversion unit 100, a part of the reflected excitation light L 415 travels toward the light guide member 104. In the wavelength conversion unit 105, a part of the reflected excitation light L 415 travels toward the light guide member 108.

[0236] The emission light L 540 is fluorescent light. The fluorescent light travels toward all directions. Thus, in the wavelength conversion unit 100, a part of the emission light L 540 travels toward the light guide member 104. In the wavelength conversion unit 105, also a part of the emission light L 540 travels toward the light guide member 108.

[0237] The wavelength conversion member 103 can have a diffusion function. For example, the diffusion function is obtained by providing a diffusion surface to the wavelength conversion member 103 or by making the wavelength conversion member 103 contain fine particles. In the case where the wavelength conversion member 103 has the diffusion function, scattered light of the excitation light L 415 and scattered light of the emission light L 540 (hereinafter referred to as "scattered light L BG ") are generated.

[0238] The scattered light L BG travels toward all directions. Thus, in the wavelength conversion unit 100, a part of the scattered light L BG travels toward the light guide member 104. In the wavelength conversion unit 105, also a part of the scattered light L BG travels toward the light guide member 108.

[0239] A diffusion member can be used instead of the wavelength conversion member 103. In the diffusion member, although fluorescent light is not generated, scattered light is generated. The scattered light travels toward all directions. Thus, in the wavelength conversion unit 100, a part of the scattered light travels toward the light guide member 104. In the wavelength conversion unit 105, also a part of the scattered light travels toward the light guide member 108.

[0240] As described above, the diameter of the second light guide region of the light guide member 104 is smaller than the diameter of the second light guide region of the light guide member 108. Thus, in the wavelength conversion unit 100, the light incident to the light guide member can be reduced compared to the wavelength conversion unit 105. As a result, in the wavelength conversion unit 100, the loss of the illumination light can be reduced compared to the wavelength conversion unit 105.

[0241] Further, the reflection surface 102a is formed in the recess. The larger the area of the reflection surface 102a, the larger the proportion of the light Ll of the first wavelength region and the light L2 of the second wavelength region that travel toward the exit end surface Ro. As Figure 10 As shown in (b) of the same drawing, in the wavelength conversion unit 105, the reflection surface 102a is not present in the range D2, in contrast to which, in the wavelength conversion unit 100, the reflection surface 102a is present in a portion corresponding to the range D2. Therefore, in the wavelength conversion unit 100, it is possible to increase the proportion of the light L2 of the second wavelength region that travels toward the exit end surface Ro, as compared with the wavelength conversion unit 105.

[0242] In the optical device of the present embodiment, the first light guide region is disposed at a position closer to the holding portion than the second light guide region. Therefore, it is possible to make the diameter of the second light guide region very small. In this case, it is possible to reduce the proportion of the light L2 of the second wavelength region that is incident on the second light guide region, and further, it is possible to increase the proportion of the light L2 of the second wavelength region that travels toward the exit end surface Ro. As a result, in the optical device of the present embodiment, it is possible to obtain bright illumination light.

[0243] (Optical device 5 of the present embodiment)

[0244] In the optical device of the present embodiment, it is preferable that the light source, the light guide member, and the light conversion member are disposed in one housing.

[0245] For example, in the optical device 20 shown in Figure 3 In this case, it is possible to consider that one housing is formed by the holding portion 21, the intermediate portion 26, and the tubular portion 22. Thus, in the optical device 20, the light source 11, the light guide member 12, and the wavelength conversion member 13 are disposed in one housing.

[0246] In the optical device 30, the optical device 40, the optical device 50, and the optical device 60 as well, the light source 11, the light guide member 12, and the wavelength conversion member 13 are disposed in one housing.

[0247] (Optical device 6 of the present embodiment)

[0248] The optical device of the present embodiment preferably has a first housing in which the light source is disposed, and a second housing in which the light guide member and the light conversion member are disposed, the first housing and the second housing being independent of each other.

[0249] For example, in the optical device 70 shown in Figure 8 In this case, it is possible to consider that one housing is formed by the light source unit 80.

[0250] Further, the connecting portion 79, the tubular portion 72, and the holding portion 71 are mechanically coupled. In this case, it can be considered that one housing is formed by the connecting portion 79, the tubular portion 72, and the holding portion 71.

[0251] Thus, the optical device 70 has two housings, i.e., a first housing and a second housing. In the optical device 70, the light source 11 is arranged in the first housing. Further, the light guide member 12 and the wavelength conversion member 13 are arranged in the second housing.

[0252] The light source unit 80 is connected to the connecting portion 79. Thus, the light source unit 80 is independent from the connecting portion 79, the tubular portion 72, and the holding portion 71. Thus, in the optical device 70, the first housing and the second housing are independent from each other.

[0253] (Optical device 7 of the present embodiment)

[0254] The optical device of the present embodiment preferably satisfies the following conditional expression (1):

[0255] LEF1 < ΔEF (1)

[0256] Herein,

[0257] LEF1 is the light coupling efficiency of the light guide member, and is expressed by LEF1 = Iout / Iin,

[0258] ΔEF is the difference in conversion efficiency of the wavelength conversion member, and is expressed by ΔEF = |EFa - EFb|,

[0259] Iout is the intensity of light incident to the incident end surface,

[0260] Iin is the intensity of light emitted from the emission end surface,

[0261] EFa is the conversion efficiency when the diameter of the emission end surface is φa,

[0262] EFb is the conversion efficiency when the diameter of the emission end surface is φb,

[0263] The conversion efficiency is expressed by Q / P,

[0264] P is the intensity of light irradiated to the wavelength conversion member,

[0265] Q is the intensity of light emitted from the wavelength conversion member,

[0266] φa is the diameter of the incident end surface,

[0267] φb is the diameter of the emission end surface.

[0268] In the optical device of the present embodiment, it is preferable that the light conversion member is a wavelength conversion member, the light of the first wavelength region is emitted from the light source, the light of the second wavelength region is generated from the light of the first wavelength region by the wavelength conversion member, the light of the second wavelength region includes light having a longer wavelength than the light of the first wavelength region, and the following conditional expression (1') is satisfied:

[0269] LEF1 < ΔEF' (1')

[0270] Here,

[0271] LEF1 is the light coupling efficiency of the light guide member, and is expressed by LEF1 = Iout / Iin,

[0272] ΔEF' is the difference in conversion efficiency of the wavelength conversion member, and is expressed by ΔEF' = |EFa' - EFb'|,

[0273] Iout is the intensity of the light incident on the incident end surface,

[0274] Iin is the intensity of the light emitted from the emission end surface,

[0275] EFa' is the conversion efficiency when the diameter of the emission end surface is φa,

[0276] EFb' is the conversion efficiency when the diameter of the emission end surface is φb,

[0277] The conversion efficiency is expressed by Q' / P',

[0278] P' is the intensity of the light of the first wavelength region irradiated to the wavelength conversion member,

[0279] Q' is the intensity of the light of the second wavelength region or the sum of the intensity of the light of the second wavelength region and the intensity of the light of the first wavelength region transmitted through the wavelength conversion member,

[0280] φa is the diameter of the incident end surface,

[0281] φb is the diameter of the emission end surface.

[0282] By satisfying the conditional expression (1) or (1'), the light emitted from the light source can be effectively utilized.

[0283] (Optical device 8 of the present embodiment)

[0284] The optical device of the present embodiment preferably satisfies the following conditional expression (2):

[0285] (φa / φb) 2 × (NAa / NAb) 2 < 1 / 2 + (1 / 2) × {(φb / (2 × d) 2 + 1} －1 / 2 (2)

[0286] Here,

[0287] φa is a diameter of the incident end surface,

[0288] φb is a diameter of the exit end surface,

[0289] NAa is a numerical aperture of the incident end surface,

[0290] NAb is a numerical aperture of the exit end surface,

[0291] d is a distance from the exit end surface to the light conversion member.

[0292] In the optical device of the present embodiment, it is preferable that the light conversion member is a wavelength conversion member, and the following conditional expression (2') is satisfied:

[0293] (φa / φb) 2 ×(NAa / NAb) 2 <1 / 2+(1 / 2)×{(φb / (2×d') 2 +1} －1 / 2 (2')

[0294] Here,

[0295] φa is a diameter of the incident end surface,

[0296] φb is a diameter of the exit end surface,

[0297] NAa is a numerical aperture of the incident end surface,

[0298] NAb is a numerical aperture of the exit end surface,

[0299] d' is a distance from the exit end surface to the wavelength conversion member.

[0300] By satisfying the conditional expression (2) or (2'), the light emitted from the light source can be effectively utilized.

[0301] (Optical device 9 of the present embodiment)

[0302] In the optical device of the present embodiment, it is preferable that a light coupler is disposed between the light source and the light guide member, and the light coupler has a core and a clad, and the diameter of the core is the same as the diameter of the incident end surface.

[0303] Figure 11 is a diagram showing the optical device of the present embodiment. In the optical device of the present embodiment, two illumination lights different in wavelength region can be used. Figure 11 (a) of is a diagram showing illumination with one illumination light. Figure 11 (b) of is a diagram showing illumination with the other illumination light.

[0304] The optical device 110 has a light coupler 111, a light guide member 12, a light guide member 118, a wavelength conversion member 93, a wavelength conversion member 103, and a light source 119.

[0305] The light guide member 118 is the same as the light guide member 12. The light guide member 118 has a first light guide region 118' and a second light guide region 118".

[0306] The light coupler 111 is disposed between the light source 119 and the light guide member 12 and between the light source 119 and the light guide member 118.

[0307] The light coupler 111 has a core 112 and a cladding layer 113. The core 112 is formed of a medium having a refractive index greater than 1. The cladding layer 113 has a refractive index smaller than that of the core.

[0308] The light coupler 111 has an incident portion 114, an incident portion 115, an exit portion 116, and an exit portion 117.

[0309] The light source 119 can be disposed on the incident portion 114 side or the incident portion 115 side. In the optical device 110, the light source 119 is disposed on the incident portion 114 side.

[0310] The light guide member 12 is located on the exit portion 116 side. In the exit portion 116, the core 112 and the light guide member 12 are formed of a single medium. Thus, in the exit portion 116, no physical boundary is formed between the core 112 and the light guide member 12.

[0311] The cladding layer 12CL is located around the light guide member 12. In the exit portion 116, the cladding layer 113 and the cladding layer 12CL are also formed of a single medium. Thus, in the exit portion 116, no physical boundary is formed between the cladding layer 113 and the cladding layer 12CL.

[0312] The light guide member 118 is located on the exit portion 117 side. In the exit portion 117, the core 112 and the light guide member 118 are formed of a single medium. Thus, in the exit portion 117, no physical boundary is formed between the core 112 and the light guide member 118.

[0313] The cladding layer 118CL is located around the light guide member 118. In the exit portion 117, the cladding layer 113 and the cladding layer 118CL are also formed of a single medium. Thus, in the exit portion 117, no physical boundary is formed between the cladding layer 113 and the cladding layer 118CL.

[0314] The light guide member 12 and the cladding layer 12CL can be formed by stretching while heating the exit portion 116. The light guide member 118 and the cladding layer 118CL can be formed by stretching while heating the exit portion 117.

[0315] A wavelength conversion member 93 is disposed on the exit end surface side of the light guide member 12. A wavelength conversion member 103 is disposed on the exit end surface side of the light guide member 118.

[0316] The maximum diameter of the light guide region 12' is the same as the diameter of the core 112 of the incident portion 114 and the diameter of the core 112 of the incident portion 115. Further, the maximum diameter of the first light guide region 118' is the same as the diameter of the core 112 of the incident portion 114 and the diameter of the core 112 of the incident portion 115.

[0317] Thus, the diameter of the core 112 of the incident portion 114 and the diameter of the core 112 of the incident portion 115 represent the maximum diameter of the first light guide region 12' and the maximum diameter of the first light guide region 118'.

[0318] A lens can be disposed between the light source 119 and the incident portion 114, for example. By disposing the lens, light emitted from the light source 119 can be efficiently incident on the core 112 of the incident portion 114.

[0319] As described above, the diameter of the core 112 of the incident portion 114 represents the maximum diameter of the first light guide region 12' and the maximum diameter of the first light guide region 118'. Thus, by causing light emitted from the light source 119 to be incident on the core 112 of the incident portion 114, light emitted from the light source 119 can be efficiently incident on the light guide member 12 and the light guide member 118.

[0320] Further, the diameter of the core 112 of the incident portion 115 represents the maximum diameter of the first light guide region 12' and the maximum diameter of the first light guide region 118'. Thus, by causing light emitted from the light source to be incident on the core 112 of the incident portion 115, light emitted from the light source can be efficiently incident on the light guide member 12 and the light guide member 118.

[0321] In this case, since bright light can be irradiated on the wavelength conversion member 93 and the wavelength conversion member 103, bright illumination light can be obtained. Thus, a clear optical image is formed. Further, a clear image can be obtained from the optical image.

[0322] Further, the diameter of the second light guide region 12" and the diameter of the second light guide region 118" are very small. Thus, in the optical device 110, the thickness of the tubular portion can be made thin. At least a part of the tubular portion is inserted into the body, for example, or into a metal pipe. Thus, the tubular portion can be easily inserted.

[0323] As described above, in the light coupler 111, the diameter of the core 112 is larger than the diameter of the second light guide region 12" and the diameter of the second light guide region 118". Thus, the light coupler 111 can be easily manufactured.

[0324] Light source 119 can emit illumination light L3 and illumination light L5. The wavelength range of illumination light L3 is different from that of illumination light L5. Illumination light L3 and illumination light L5 are not emitted from light source 119 at the same time. When one illumination light is emitted from light source 119, the other illumination light is not emitted from light source 119.

[0325] In the optical device 110, it is used as a wavelength conversion component. Figure 9 The wavelength conversion element 93 shown in (a) and Figure 10 The wavelength conversion component 103 is shown in (a). Therefore, using the excitation light L... 450 As the illumination light L3, the excitation light L is used 415 As illumination light L5.

[0326] The illumination using illumination light L3 will be explained. For example... Figure 11 As shown in (a), illumination light L3 is emitted from light source 119. Illumination light L3 is incident from incident portion 114 onto optical coupler 111. Illumination light L3 is split into two optical paths. Illumination light L3 traveling in one optical path is emitted from exit portion 116. Illumination light L3 traveling in the other optical path is emitted from exit portion 117.

[0327] Illumination light L3, which enters the light guide member 12 from the emission part 116, travels in the light guide member 12 and then illuminates the wavelength conversion member 93. Illumination light L3, which enters the light guide member 118 from the emission part 117, travels in the light guide member 118 and then illuminates the wavelength conversion member 103.

[0328] When illumination light L3 is irradiated onto wavelength conversion member 93, fluorescence L4 is generated from wavelength conversion member 93. As a result, illumination light L3 and fluorescence L4 are emitted from wavelength conversion member 93. Even when illumination light L3 is irradiated onto wavelength conversion member 103, no fluorescence is generated from wavelength conversion member 103. Therefore, only illumination light L3 is emitted from wavelength conversion member 103.

[0329] Using excitation light L in illumination light L3 450 In this case, as fluorescence L4, emitted radiation L from wavelength conversion component 93 575 As a result, light that is approximately white is emitted from the wavelength conversion member 93. Furthermore, blue light is emitted from the wavelength conversion member 103. By appropriately setting the intensity of the illumination light L3, observation can be performed using white light.

[0330] The illumination using illumination light L5 will be explained. For example... Figure 11 As shown in (b), illumination light L5 is emitted from light source 119. Illumination light L5 is incident on optical coupler 111. Illumination light L5 travels in the same manner as illumination light L3 in optical coupler 111. Therefore, detailed description is omitted.

[0331] Even when illumination light L5 is irradiated onto wavelength conversion member 93, no fluorescence is produced. Therefore, only illumination light L5 is emitted from wavelength conversion member 93. When illumination light L5 is irradiated onto wavelength conversion member 103, fluorescence L6 is generated from wavelength conversion member 103. As a result, illumination light L5 and fluorescence L6 are emitted from wavelength conversion member 103.

[0332] Using excitation light L5 in illumination light L5 415 In this case, as fluorescence L6, emitted radiation L from wavelength conversion component 103 540 As a result, light that is approximately blue-green is emitted from wavelength conversion member 103. Additionally, violet light is emitted from wavelength conversion member 93. By appropriately setting the intensity of illumination light L5, NBI (Narrow Band Imaging) can be performed.

[0333] As described above, bright illumination light can be obtained in the optical device 110. Therefore, a vivid optical image is formed by both observation using white light and NBI (Natural Image Interpretation). Furthermore, a vivid image can be acquired from the optical image.

[0334] One or both of wavelength conversion members 93 and 103 can be replaced with a diffusion member. In this case, bright illumination light can also be obtained. Therefore, a sharp optical image is formed. Furthermore, a sharp image can be acquired from the optical image.

[0335] Figure 12 This diagram illustrates the optical device of this embodiment. In the optical device of this embodiment, two illumination lights with different wavelength ranges can be used. Figure 12 (a) is a diagram showing illumination using a single light source. Figure 12 (b) is a diagram showing illumination using another light source. (Regarding the relationship between...) Figure 11 (a) The same structures are labeled with the same reference numerals, and the descriptions are omitted.

[0336] The optical device 120 includes an optical coupler 111, a light guide component 12, a light guide component 118, a wavelength conversion component 93, a wavelength conversion component 103, a light source 121, and a light source 122.

[0337] A light source 121 is disposed on the incident portion 114 side. A light source 122 is disposed on the incident portion 115 side. An optical coupler 111 is disposed between the light source 121 and the light guide member 12, and between the light source 122 and the light guide member 118.

[0338] The light guide member 12 is located on the side of the exit portion 116. In the exit portion 116, the core 112 and the light guide member 12 are not formed of a single medium. Thus, in the exit portion 116, a physical boundary is formed between the core 112 and the light guide member 12.

[0339] In the exit portion 116, the cladding 113 and the cladding 12CL are also not formed of a single medium. Thus, in the exit portion 116, a physical boundary is formed between the cladding 113 and the cladding 12CL.

[0340] The light guide member 118 is located on the side of the exit portion 117. In the exit portion 117, the core 112 and the light guide member 118 are not formed of a single medium. Thus, in the exit portion 117, a physical boundary is formed between the core 112 and the light guide member 118.

[0341] In the exit portion 117, the cladding 113 and the cladding 118CL are also not formed of a single medium. Thus, in the exit portion 117, a physical boundary is formed between the cladding 113 and the cladding 118CL.

[0342] The diameter of the incident end face 12a is the same as the diameter of the core 112. Further, the diameter of the incident end face 118a is the same as the diameter of the core 112. In this way, the diameter of the core 112 represents the diameter of the incident end face 12a and the diameter of the incident end face 118a.

[0343] A lens can be disposed, for example, between the light source 121 and the incident portion 114. By disposing the lens, it is possible to efficiently cause the light emitted from the light source 121 to be incident on the core 112 of the incident portion 114.

[0344] A lens can be disposed, for example, between the light source 122 and the incident portion 114. By disposing the lens, it is possible to efficiently cause the light emitted from the light source 122 to be incident on the core 112 of the incident portion 115.

[0345] As described above, the diameter of the core 112 represents the diameter of the incident end face 12a and the diameter of the incident end face 118a. Thus, by causing the light emitted from the light source 121 to be incident on the core 112 of the incident portion 114, it is possible to efficiently cause the light emitted from the light source 121 to be incident on the light guide member 12 and the light guide member 118.

[0346] Further, by causing the light emitted from the light source 122 to be incident on the core 112 of the incident portion 115, it is possible to efficiently cause the light emitted from the light source 122 to be incident on the light guide member 12 and the light guide member 118.

[0347] In this case, since bright light can be irradiated to the wavelength conversion member 93 and the wavelength conversion member 103, bright illumination light can be obtained. Therefore, a clear optical image is formed. Further, a clear image can be obtained from the optical image.

[0348] Further, the diameter of the second light guide region 12" and the diameter of the second light guide region 118" are very small. Therefore, in the optical device 120, the thickness of the tubular portion can be made thin. At least a part of the tubular portion is inserted, for example, into the body or into a metal pipe. Thus, the tubular portion can be easily inserted.

[0349] As described above, in the optical coupler 111, the diameter of the core 112 is larger than the diameter of the second light guide region 12" and the diameter of the second light guide region 118". Therefore, the optical coupler 111 can be easily manufactured.

[0350] The light source 121 can emit the illumination light L3. The light source 122 can emit the illumination light L5. The illumination light L3 and the illumination light L5 are not emitted at the same time. When one of the illumination lights is emitted from the light source, the other illumination light is not emitted from the light source.

[0351] As described above, in the optical coupler 111, the diameter of the core 112 is larger than the diameter of the second light guide region 12" and the diameter of the second light guide region 118". Therefore, the optical coupler 111 can be easily manufactured. Figure 12 As shown in (a) of FIG. 9, in a case where the illumination light L3 is emitted from the light source 121, the illumination light L3 and the fluorescent light L4 are emitted from the wavelength conversion member 93, and only the illumination light L3 is emitted from the wavelength conversion member 103.

[0352] As shown in (a) of FIG. 9, in a case where the illumination light L3 is emitted from the light source 121, the illumination light L3 and the fluorescent light L4 are emitted from the wavelength conversion member 93, and only the illumination light L3 is emitted from the wavelength conversion member 103. Figure 12 As shown in (b) of FIG. 9, in a case where the illumination light L5 is emitted from the light source 122, only the illumination light L5 is emitted from the wavelength conversion member 93, and the illumination light L5 and the fluorescent light L6 are emitted from the wavelength conversion member 103.

[0353] As a result, in the optical device 120, bright illumination light can be obtained as in the optical device 110. Therefore, a clear optical image is formed by both observation with white light and NBI. Further, a clear image can be obtained from the optical image.

[0354] (Optical device 10 of the present embodiment)

[0355] The optical device of the present embodiment preferably satisfies the following conditional expression (3):

[0356] LEF1cou < ΔEF (3)

[0357] Here,

[0358] LEF1cou = LEF1 + ΔLEFcou

[0359] LEF1 is the light coupling efficiency of the light guide member, and is expressed by LEF1 = Iout / Iin,

[0360] ΔLEFcou is a difference in light coupling efficiency of the light coupler, and is represented by ΔLEFcou = |LEFcoua - LECoub|

[0361] Iout is an intensity of light incident to the incident end surface,

[0362] Iin is an intensity of light emitted from the emission end surface,

[0363] LEFcoua is a light coupling efficiency when the diameter of the core is φa,

[0364] LEFcoua is a light coupling efficiency when the diameter of the core is φa,

[0365] ΔEF is a difference in conversion efficiency of the light conversion member, and is represented by ΔEF = |EFa - EFb|,

[0366] EFa is a conversion efficiency when the diameter of the emission end surface is φa,

[0367] EFa is a conversion efficiency when the diameter of the emission end surface is φa,

[0368] EFa is a conversion efficiency when the diameter of the emission end surface is φa,

[0369] P is an intensity of light irradiated to the light conversion member,

[0370] Q is an intensity of light radiated from the light conversion member,

[0371] φa is a diameter of the incident end surface,

[0372] φa is a diameter of the incident end surface,

[0373] In the optical device of the present embodiment, it is preferable that the light conversion member is a wavelength conversion member, that light of a first wavelength region is emitted from the light source, that light of a second wavelength region is generated from the light of the first wavelength region by the wavelength conversion member, that light of a longer wavelength than the light of the first wavelength region is contained in the light of the second wavelength region, and that the following conditional expression (3') is satisfied:

[0374] LEF1cou < ΔEF' (3')

[0375] Here,

[0376] LEF1cou = LEF1 + ΔLEFcou

[0377] LEF1 is a light coupling efficiency of the light guide member, and is represented by LEF1 = Iout / Iin,

[0378] ΔLEFcou is a difference in light coupling efficiency of the light coupler, and is represented by ΔLEFcou = |LEFcoua - LECoub|

[0379] Iout is the intensity of light incident to the incident end surface,

[0380] Iin is the intensity of light emitted from the emission end surface,

[0381] LEFcoa is the light coupling efficiency when the diameter of the core is φa,

[0382] LEFcoa is the light coupling efficiency when the diameter of the core is φa,

[0383] ΔEF' is the difference in the conversion efficiency of the wavelength conversion member, and is expressed by ΔEF' = |EFa' - EFb'|,

[0384] EFa' is the conversion efficiency when the diameter of the emission end surface is φa,

[0385] EFa' is the conversion efficiency when the diameter of the emission end surface is φa,

[0386] The conversion efficiency is expressed by Q' / P',

[0387] P' is the intensity of light of the first wavelength region irradiated to the wavelength conversion member,

[0388] Q' is the intensity of light of the second wavelength region or the sum of the intensity of light of the second wavelength region and the intensity of light of the first wavelength region transmitted through the wavelength conversion member,

[0389] φa is the diameter of the incident end surface,

[0390] φa is the diameter of the incident end surface,

[0391] By satisfying the conditional expression (3) or (3'), it is possible to effectively use the light emitted from the light source.

[0392] (Optical device 11 of the present embodiment)

[0393] In the optical device of the present embodiment, it is preferable that a pair of optical connectors be disposed between the light source and the light guide member, the optical connectors have the light guide member and a holding member, and the diameter of the light guide member of the optical connector be the same as the diameter of the incident end surface.

[0394] Figure 13 is a view showing the optical device of the present embodiment. Figure 13 (a) of is a view showing the structure of the optical device. Figure 13 (b) of is a view showing the structure of the optical connector. The same reference numerals are attached to the same structures as (a) of Figure 2 The same reference numerals are attached to the same structures as (a) of and the explanation is omitted.

[0395] As Figure 13As shown in (a), the optical device 130 has a light source 11, a pair of optical connectors 131, a light guide member 12, and a wavelength conversion member 13. The pair of optical connectors 131 has an optical connector 132 and an optical connector 133.

[0396] A pair of optical connectors 131 are located on the side closer to the light source 11 than the light guide member 12. Therefore, a pair of optical connectors 131 are disposed between the light source 11 and the light guide member 12.

[0397] Optical connector 132 is located on the side of light source 11, and optical connector 133 is located on the side of light guide member 12. Optical connector 132 has light guide member 134 and cladding 134CL. Optical connector 133 has light guide member 135 and cladding 135CL. Light guide member 134 and light guide member 135 are formed of a medium with a refractive index greater than 1.

[0398] The specific construction of a pair of optical connectors 131 will be described. For example... Figure 13 As shown in (b), the optical connector 132 has an optical fiber 136 and a retaining member 137. The optical fiber 136 has a light guiding member 134 and a cladding 134CL.

[0399] The optical connector 133 has an optical fiber 138 and a retaining member 139. The optical fiber 138 has a light guiding member 135 and a cladding 135CL.

[0400] Retaining member 137 and retaining member 139 are connected via optical adapter ADP. A through hole is formed in the optical adapter ADP. By inserting retaining member 137 and retaining member 139 into the through hole, light guide member 134 and light guide member 135 can be connected.

[0401] Return to Figure 13 (a) will be described. Cladding 134CL is located around light guide member 134. Cladding 135CL is located around light guide member 135.

[0402] Light guide member 135 and light guide member 12 are formed from a single medium. Therefore, no physical boundary is formed between light guide member 135 and light guide member 12. Cladding layer 135CL and cladding layer 12CL are also formed from a single medium. Therefore, no physical boundary is formed between cladding layer 135CL and cladding layer 12CL.

[0403] A wavelength conversion component 13 is disposed on the emitting end face side of the light guide component 12.

[0404] The maximum diameter of the first light guide region 12' is the same as the diameter of the light guide member 135. The diameter of the light guide member 135 is the same as the diameter of the light guide member 134. Thus, the maximum diameter of the first light guide region 12' is the same as the diameter of the light guide member 134. In this way, the diameter of the light guide member 134 represents the maximum diameter of the first light guide region 12'.

[0405] A lens can be disposed between the light source 11 and the light guide member 134, for example. By disposing the lens, light emitted from the light source 11 can be efficiently incident on the light guide member 134.

[0406] As described above, the diameter of the light guide member 134 represents the maximum diameter of the first light guide region 12'. Thus, by causing light emitted from the light source 11 to be incident on the light guide member 134, light emitted from the light source 11 can be efficiently incident on the light guide member 12.

[0407] In this case, since bright light can be irradiated on the wavelength conversion member 13, bright illumination light can be obtained. Thus, a clear optical image is formed. Further, a clear image can be acquired from the optical image.

[0408] The wavelength conversion member 13 can be replaced with a diffusion member. In this case, too, bright illumination light can be obtained. Thus, a clear optical image is formed. Further, a clear image can be acquired from the optical image.

[0409] Further, the diameter of the second light guide region 12" is very small. Thus, in the optical device 130, the thickness of the tubular portion can be made thin. At least a portion of the tubular portion is inserted into the body, for example, or into a metal pipe. Thus, the tubular portion can be easily inserted.

[0410] The optical device 130 has a pair of optical connectors 131. In this case, the optical device 130 can be divided into two housings by the optical adapter ADP, for example. Thus, the other housing can be disposed at various positions with respect to one housing.

[0411] One housing has the light source 11. The other housing has the light guide member 12 and the wavelength conversion member 13. Connection of the two housings is performed by connection of the optical connector 132 and the optical connector 133.

[0412] By connecting the optical connector 132 and the optical connector 133, the light guide member 134 and the light guide member 135 are connected. As a result, light emitted from the light source 11 propagates using the light guide member 134 and the light guide member 135. When the light guide member 134 and the light guide member 135 are connected, if misalignment occurs between the light guide member 134 and the light guide member 135, loss of light occurs.

[0413] In the optical device 130, the diameter of the light guide member 134 and the diameter of the light guide member 135 are larger than the diameter of the second light guide region 12". Thus, even if misalignment occurs between the light guide member 134 and the light guide member 135, it is possible to reduce the loss of light at the time of connection.

[0414] Figure 14 is a view that shows the optical device of the present embodiment. The same reference numerals are given to the same structures as those of (a) of Figure 11 The same reference numerals are given to the same structures as those of (a) of

[0415] The optical device 140 has the optical coupler 111, a pair of optical connectors 141, a pair of optical connectors 142, the light guide member 12, the light guide member 118, the wavelength conversion member 93, the wavelength conversion member 103, and the light source 119.

[0416] The pair of optical connectors 141 has an optical connector 143 and an optical connector 144. The pair of optical connectors 142 has an optical connector 145 and an optical connector 146.

[0417] The pair of optical connectors 141 is located at a position closer to the light source 119 than the light guide member 12. Thus, the pair of optical connectors 141 is disposed between the light source 119 and the light guide member 12.

[0418] The pair of optical connectors 142 is located at a position closer to the light source 119 than the light guide member 118. Thus, the pair of optical connectors 142 is disposed between the light source 119 and the light guide member 118.

[0419] The optical coupler 111 and the pair of optical connectors 141 are disposed between the light source 119 and the light guide member 12. The optical coupler 111 is located at a position closer to the light source 119 than the pair of optical connectors 141.

[0420] The optical coupler 111 and the pair of optical connectors 142 are disposed between the light source 119 and the light guide member 118. The optical coupler 111 is located at a position closer to the light source 119 than the pair of optical connectors 142.

[0421] The optical connector 143 is located on the exit portion 116 side. In the exit portion 116, the core 112 and the light guide member of the optical connector 143 are formed of a single medium. Thus, in the exit portion 116, no physical boundary is formed between the core 112 and the light guide member of the optical connector 143.

[0422] The optical connector 144 is located next to the optical connector 143. The light guide member of the optical connector 144 and the light guide member 12 are formed of a single medium. Thus, no physical boundary is formed between the light guide member of the optical connector 144 and the light guide member 12.

[0423] The optical connector 145 is located on the side of the exit portion 117. In the exit portion 117, the core 112 and the light guide member of the optical connector 145 are formed of a single medium. Thus, in the exit portion 117, no physical boundary is formed between the core 112 and the light guide member of the optical connector 145.

[0424] The optical connector 146 is located next to the optical connector 145. The light guide member of the optical connector 146 and the light guide member 118 are formed of a single medium. Thus, no physical boundary is formed between the light guide member of the optical connector 146 and the light guide member 118.

[0425] The maximum diameter of the first light guide region 12' is the same as the diameter of the light guide member of the optical connector 144. The diameter of the light guide member of the optical connector 144 is the same as the diameter of the light guide member of the optical connector 143.

[0426] Also, the diameter of the light guide member of the optical connector 143 is the same as the diameter of the core 112 of the entrance portion 114 and the diameter of the core 112 of the entrance portion 115. Thus, the maximum diameter of the first light guide region 12' is the same as the diameter of the core 112 of the entrance portion 114 and the diameter of the core 112 of the entrance portion 115.

[0427] If the diameter of the light guide member of the optical connector 143 is different from the diameter of the core 112 of the entrance portion 114, light quantity loss occurs between the light guide member of the optical connector 143 and the core 112 of the entrance portion 114. As a result, the coupling efficiency decreases.

[0428] However, as long as the size is such that the light quantity loss or the decrease in the imaging light efficiency is allowed to a certain extent, the diameter of the light guide member of the optical connector 143 can be considered to be the same as the diameter of the core 112 of the entrance portion 114. The diameter of the light guide member of the optical connector 143 is also the same as the diameter of the core 112 of the entrance portion 115. Furthermore, the connection of the optical coupler shown in (b) of FIG. 1 is also the same. Figure 12

[0429] The maximum diameter of the first light guide region 118' is the same as the diameter of the light guide member of the optical connector 146. The diameter of the light guide member of the optical connector 146 is the same as the diameter of the light guide member of the optical connector 145.

[0430] Also, the diameter of the light guide member of the optical connector 145 is the same as the diameter of the core 112 of the entrance portion 114 and the diameter of the core 112 of the entrance portion 115. Thus, the maximum diameter of the first light guide region 118' is the same as the diameter of the core 112 of the entrance portion 114 and the diameter of the core 112 of the entrance portion 115.

[0431] ​Thus, the diameter of the core 112 of the incident portion 114 and the diameter of the core 112 of the incident portion 115 represent the maximum diameter of the first light guide region 12' and the maximum diameter of the first light guide region 118'.

[0432] Thus, by causing the light emitted from the light source 119 to be incident on the core 112 of the incident portion 114, it is possible to efficiently cause the light emitted from the light source 119 to be incident on the light guide member 12 and the light guide member 118.

[0433] Further, by causing the light emitted from the light source to be incident on the core 112 of the incident portion 115, it is possible to efficiently cause the light emitted from the light source to be incident on the light guide member 12 and the light guide member 118.

[0434] In this case, since it is possible to irradiate the wavelength conversion member 93 and the wavelength conversion member 103 with bright light, it is possible to obtain bright illumination light. Thus, a clear optical image is formed. Further, it is possible to acquire a clear image from the optical image.

[0435] In Figure 14 a case where the illumination light L3 is emitted from the light source 119 is shown. As described above, the light source 119 can emit not only the illumination light L3 but also the illumination light L5. Thus, in the optical device 140, it is possible to perform observation with white light and NBI. In either case, bright illumination light can be obtained.

[0436] One or both of the wavelength conversion member 93 and the wavelength conversion member 103 can be replaced with a diffusion member. In this case, too, bright illumination light can be obtained.

[0437] The optical device 140 has a pair of optical connectors. Thus, it is possible to divide the device into two housings. In this case, the other housing can be disposed at various positions with respect to one housing. Connection of the two housings is performed using the pair of optical connectors 141 and the pair of optical connectors 142.

[0438] In the optical device 140, loss of light at the time of connection is small, and bright illumination light can be obtained. Thus, a clear optical image is formed. Further, it is possible to acquire a clear image from the optical image.

[0439] Figure 15 is a view that shows the optical device of the present embodiment. The same reference numerals are attached to the same structures as in (a) of Figure 12 of the present embodiment. The same reference numerals are attached to the same structures as in (a) of

[0440] The optical device 150 has the optical coupler 111, a pair of optical connectors 151, a pair of optical connectors 152, the light guide member 12, the light guide member 118, the wavelength conversion member 93, the wavelength conversion member 103, and the light sources 121 and 122.

[0441] The pair of optical connectors 151 has an optical connector 153 and an optical connector 154. The pair of optical connectors 152 has an optical connector 155 and an optical connector 156.

[0442] The pair of optical connectors 151 is located on the light source 121 side of the light guide member 12. Thus, the pair of optical connectors 151 is arranged between the light source 121 and the light guide member 12.

[0443] The pair of optical connectors 152 is located on the light source 122 side of the light guide member 118. Thus, the pair of optical connectors 152 is arranged between the light source 122 and the light guide member 118.

[0444] The optical coupler 111 and the pair of optical connectors 151 are arranged between the light source 121 and the light guide member 12. The optical coupler 111 is located on the light source 121 side of the pair of optical connectors 151.

[0445] The optical coupler 111 and the pair of optical connectors 152 are arranged between the light source 122 and the light guide member 118. The optical coupler 111 is located on the light source 122 side of the pair of optical connectors 152.

[0446] The optical connector 153 is located on the exit portion 116 side. In the exit portion 116, the light guide member of the optical connector 153 and the core 112 are not formed by a single medium. Thus, a physical boundary is formed between the light guide member of the optical connector 153 and the core 112.

[0447] The optical connector 154 is located next to the optical connector 153. The light guide member of the optical connector 154 and the light guide member 12 are not formed by a single medium. Thus, a physical boundary is formed between the light guide member of the optical connector 154 and the light guide member 12.

[0448] The optical connector 155 is located on the exit portion 117 side. The light guide member of the optical connector 155 and the core 112 are not formed by a single medium. Thus, a physical boundary is formed between the light guide member of the optical connector 155 and the core 112.

[0449] The optical connector 156 is located next to the optical connector 155. The light guide member of the optical connector 156 and the light guide member 118 are not formed by a single medium. Thus, a physical boundary is formed between the light guide member of the optical connector 156 and the light guide member 118.

[0450] The diameter of the incident end face 12a is the same as the diameter of the light guide member of the optical connector 154. The diameter of the light guide member of the optical connector 154 is the same as the diameter of the light guide member of the optical connector 153.

[0451] Also, the diameter of the light guide member of the optical connector 155 is the same as the diameter of the core 112. Thus, the diameter of the incident end face 118a is the same as the diameter of the core 112.

[0452] The diameter of the incident end face 118a is the same as the diameter of the light guide member of the optical connector 156. The diameter of the light guide member of the optical connector 156 is the same as the diameter of the light guide member of the optical connector 155.

[0453] Also, the diameter of the light guide member of the optical connector 155 is the same as the diameter of the core 112. Thus, the diameter of the incident end face 118a is the same as the diameter of the core 112.

[0454] Thus, the diameter of the core 112 indicates the maximum diameter of the incident end face 12a and the diameter of the incident end face 118a.

[0455] Thus, by causing the light emitted from the light source 121 to be incident on the core 112 of the incident portion 114, it is possible to efficiently cause the light emitted from the light source 121 to be incident on the light guide member 12 and the light guide member 118.

[0456] Further, by causing the light emitted from the light source 122 to be incident on the core 112 of the incident portion 115, it is possible to efficiently cause the light emitted from the light source 122 to be incident on the light guide member 12 and the light guide member 118.

[0457] In this case, since it is possible to irradiate the wavelength conversion member 93 and the wavelength conversion member 103 with bright light, it is possible to obtain bright illumination light. Thus, a clear optical image is formed. Further, it is possible to acquire a clear image from the optical image.

[0458] In Figure 15 the case where the illumination light L3 is emitted from the light source 121 is shown. As described above, the illumination light L5 is emitted from the light source 122. Thus, in the optical device 150, it is possible to perform observation with white light and NBI. In either case, bright illumination light is obtained.

[0459] One or both of the wavelength conversion member 93 and the wavelength conversion member 103 can be replaced with a diffusion member. In this case, too, bright illumination light is obtained.

[0460] The optical device 150 has a pair of optical connectors. Therefore, it is possible to divide the device into two housings. In this case, it is possible to arrange one housing at various positions with respect to the other housing. The connection of the two housings is performed using the pair of optical connectors 151 and the pair of optical connectors 152.

[0461] In the optical device 150, the loss of light at the time of connection is small, and it is possible to obtain bright illumination light. Therefore, a clear optical image is formed. Furthermore, it is possible to acquire a clear image from the optical image.

[0462] (Optical device 12 of the present embodiment)

[0463] The optical device of the present embodiment preferably satisfies the following conditional expression (4);

[0464] LEF1cne < ΔEF (4)

[0465] Here,

[0466] LEF1cne = LEF1 + ΔLEFcne

[0467] LEF1 is the light coupling efficiency of the light guide member, and is expressed by LEF1 = Iout / Iin,

[0468] ΔLEFcne is the difference in the light coupling efficiency of the optical connectors, and is expressed by ΔLEFcne = |LEFcnea - LEFcneb|,

[0469] Iout is the intensity of light incident to the incident end surface,

[0470] Iin is the intensity of light emitted from the emission end surface,

[0471] LEFcnea is the light coupling efficiency when the diameter of the light guide member of the optical connector is φa,

[0472] LEFcneb is the light coupling efficiency when the diameter of the light guide member of the optical connector is φb,

[0473] ΔEF is the difference in the conversion efficiency of the light conversion member, and is expressed by ΔEF = |EFa - EFb|,

[0474] EFa is the conversion efficiency when the diameter of the emission end surface is φa,

[0475] EFb is the conversion efficiency when the diameter of the emission end surface is φb,

[0476] The conversion efficiency is expressed by Q / P,

[0477] P is the intensity of light irradiated to the light conversion member,

[0478] Q is an intensity of light emitted from the light-converting member,

[0479] φa is a diameter of the incident end surface,

[0480] φb is a diameter of the exit end surface.

[0481] Preferably, the light-converting member is a wavelength-converting member, light of a first wavelength region is emitted from the light source, light of a second wavelength region is generated from the light of the first wavelength region by the wavelength-converting member, the light of the second wavelength region contains light having a longer wavelength than the light of the first wavelength region, and the following conditional expression (4') is satisfied;

[0482] LEF1cne < ΔEF' (4')

[0483] Here,

[0484] LEF1cne = LEF1 + ΔLEFcne

[0485] LEF1 is a light coupling efficiency of the light guide member, and is expressed by LEF1 = Iout / Iin,

[0486] ΔLEFcne is a difference in light coupling efficiency of the optical connector, and is expressed by ΔLEFcne = |LEFcnea - LEFcneb|,

[0487] Iout is an intensity of light incident on the incident end surface,

[0488] Iin is an intensity of light emitted from the exit end surface,

[0489] LEFcnea is a light coupling efficiency of the light guide member of the optical connector when the diameter is φa,

[0490] LEFcneb is a light coupling efficiency of the light guide member of the optical connector when the diameter is φb,

[0491] ΔEF' is a difference in conversion efficiency of the wavelength-converting member, and is expressed by ΔEF' = |EFa' - EFb'|,

[0492] EFa' is a conversion efficiency when the diameter of the exit end surface is φa,

[0493] EFb' is a conversion efficiency when the diameter of the exit end surface is φb,

[0494] The conversion efficiency is expressed by Q' / P',

[0495] P' is an intensity of light of the first wavelength region irradiated to the wavelength-converting member,

[0496] Q' is an intensity of light of the second wavelength region or a sum of an intensity of light of the second wavelength region and an intensity of light of the first wavelength region transmitted through the wavelength-converting member.

[0497] φa is the diameter of the incident end face.

[0498] φb is the diameter of the exit end face.

[0499] By satisfying condition (4) or (4'), it is possible to effectively utilize the light emitted from the light source.

[0500] The light in the first wavelength domain that is irradiated onto the wavelength conversion component is the light emitted from the exit end face of the light guide component. Therefore, P' in the conditions (1'), (3'), and (4') can be called "the intensity of the light in the first wavelength domain emitted from the exit end face of the light guide component".

[0501] like Figure 9 As shown in (a), the wavelength conversion unit has an incident end face Ri and an exit end face Ro. In the wavelength conversion unit, the light emitted from the exit end face Ro is used as illumination light.

[0502] As described above, in the wavelength conversion component, light from the first wavelength domain is generated into light in the second wavelength domain. Since the light in the second wavelength domain is fluorescent, it travels in all directions.

[0503] The wavelength conversion member has a surface located on the incident end face Ri and a surface located on the exit end face Ro. Therefore, in the wavelength conversion member, light in the second wavelength domain is emitted from the surface located on the incident end face Ri and the surface located on the exit end face Ro.

[0504] In conditional expressions (1'), (3'), and (4'), Q' represents the intensity of the light that can be used as illumination light. As described above, the light that can be used as illumination light is light emitted from the emission end face Ro. The light emitted from the emission end face Ro is light emitted from the surface located on the side of the emission end face Ro. Therefore, the light that can be used as illumination light is light emitted from the surface located on the side of the emission end face Ro.

[0505] The intensity of light in the second wavelength domain of Q' means the intensity of light emitted from the surface located on the emitting end face Ro. The same applies to the intensity of light in the first wavelength domain.

[0506] (Optical device 13 in this embodiment)

[0507] The optical device of this embodiment preferably has a housing having a holding part and a tubular part, and a light source, a pair of optical connectors, a light guide member and a light conversion member are disposed in the housing.

[0508] Figure 16 This is a diagram illustrating the optical device of this embodiment. (Regarding...) Figure 3 (a) Same structure and with Figure 13 (a) The same structures are labeled with the same reference numerals, and the descriptions are omitted.

[0509] The optical device 160 is a wireless endoscope. The optical device 160 has a housing 161. The housing 161 has a holding part 21, a tubular part 22, and an intermediate part 26. The intermediate part 26 can be provided as needed.

[0510] Inside the housing 161 are arranged a light source 11, a lens 162, an optical connector 132, an optical adapter ADP, an optical connector 133, a light guide component 12, and a wavelength conversion component 13. Optical connectors 132 and 133 form a pair of optical connectors.

[0511] Light emitted from light source 11 is focused by lens 162. A light guide member of optical connector 132 is disposed at the focusing position. Therefore, light emitted from light source 11 can be directed into the light guide member of optical connector 132.

[0512] exist Figure 16 In this configuration, optical connectors 132 and 133 are not connected to the optical adapter ADP. By connecting optical connectors 132 and 133 to the optical adapter ADP, the light guide component of optical connector 132 is connected to the light guide component of optical connector 133. As a result, light incident on the light guide component of optical connector 132 can be directed to the light guide component of optical connector 133.

[0513] The light guide members 133 and 12 of the optical connector are formed of a single medium. Therefore, light emitted from the optical connector 133 enters the light guide member 12. Light incident on the light guide member 12 exits from the light guide member 12. Light exiting the light guide member 12 illuminates the wavelength conversion member 13.

[0514] In the optical device 160, a pair of optical connectors are arranged inside a housing 161. Therefore, during manufacturing, the light source 11 side and the light guide member 12 side can be manufactured separately, with the connectors as the boundary. This increases manufacturing flexibility. Furthermore, maintenance becomes easier.

[0515] (Optical device 14 in this embodiment)

[0516] The optical device of this embodiment preferably has a first housing and a second housing, the first housing having an optical connector and the second housing having another optical connector.

[0517] Figure 17 This is a diagram illustrating the optical device of this embodiment. (Regarding...) Figure 8 Same structure and Figure 16 The same structures are labeled with the same reference numerals in the attached figures, and the descriptions are omitted.

[0518] The optical device 170 is a non-wireless endoscope. The optical device 170 has a first housing 171 and a second housing 172. The first housing 171 has a light source unit 80. The second housing 172 has a holding part 71, a first tubular part 73, and a second tubular part 74.

[0519] The first housing 171 houses a light source 11, a lens 162, an optical connector 132, and an optical adapter ADP. The second housing 172 houses a light guide component 12 and a wavelength conversion component 13.

[0520] The first tubular portion 73 and the second tubular portion 74 are occupied by the second light guiding region 12". The optical connector 133 is located at the front end of the second tubular portion 74. The first light guiding region 12' is located near the optical connector 133.

[0521] In the optical device 170, the first tubular portion 73 and the second tubular portion 74 are occupied by the second light guiding region 12". Therefore, the first tubular portion 73 and the second tubular portion 74 can be made thinner. As a result, the first tubular portion 73 can be easily inserted into the body or metal tube. In addition, the processing of the second housing 172 becomes easier.

[0522] In the optical device 170, the first housing 171 and the second housing 172 are connected by a pair of optical connectors. Therefore, the first housing and the second housing can be manufactured separately during production. This increases manufacturing flexibility. Furthermore, maintenance becomes easier.

[0523] Alternatively, the first housing can be used relative to multiple second housings. In this case, simply select one second housing from the multiple second housings and connect the selected second housing to the first housing. Even if the second housing is discarded after use, the first housing can be reused repeatedly.

[0524] (Optical device 15 in this embodiment)

[0525] Figure 18 This is a diagram illustrating the optical device of this embodiment. (Regarding...) Figure 17 The same structures are labeled with the same reference numerals in the attached figures, and the descriptions are omitted.

[0526] The optical device 180 is a non-wireless endoscope. The optical device 180 has a first housing 181 and a second housing 182. The first housing 181 has a light source unit 80. The second housing 182 has a holding part 71, a first tubular part 73, and a second tubular part 74.

[0527] In the inside of the first housing 181, the light source 11, the lens 162, the optical connector 183, the optical adapter ADP, the optical connector 184, the optical connector 132, and the optical adapter ADP are arranged. In the inside of the second housing 182, the light guide member 12 and the wavelength conversion member 13 are arranged.

[0528] The first tubular portion 73 is occupied by the second light guide region 12". The optical connector 133 is located at the front end of the second tubular portion 74. The first light guide region 12' is located in the inside of the second housing 172.

[0529] In the optical device 180, the first tubular portion 73 is occupied by the second light guide region 12". Therefore, the first tubular portion 73 can be made thin. As a result, the first tubular portion 73 can be easily inserted into the body or the metal pipe.

[0530] Also in the optical device 170, the first tubular portion 73 and the second tubular portion 74 can be occupied by the second light guide region 12".

[0531] In the optical device 180, a pair of optical connectors are arranged in the inside of the first housing 181. Thus, the first housing and the second housing can be manufactured separately at the time of manufacture. Therefore, the degree of freedom of manufacture can be increased. Further, maintenance becomes easy.

[0532] (Optical device 16 of the present embodiment)

[0533] The optical device of the present embodiment preferably has a light conversion unit having a holding member, a reflecting member, and a light conversion member, a recess is formed in the holding member, the reflecting member and the light conversion member are arranged in the recess, the diameter of one end surface of the recess is smaller than the diameter of the other end surface of the recess, and the one end surface of the recess is located on the exit end side.

[0534] As for the light conversion unit, since the first example of the wavelength conversion unit (wavelength conversion unit 90), the second example of the wavelength conversion unit (wavelength conversion unit 100), and the light diffusion unit are described, the description is omitted.

[0535] The wavelength conversion member can also contain fine particles. The light can be diffused by the fine particles. Further, a diffusion member can be arranged separately from the wavelength conversion member. For example, in the wavelength conversion unit 90, the diffusion member can be arranged beside the wavelength conversion member 93. Only the diffusion member can be arranged.

[0536] Further, a plurality of wavelength conversion members can be arranged. For example, in the wavelength conversion unit 100, the wavelength conversion member 93 can be arranged beside the wavelength conversion member 103.

[0537] (Optical device 17 of the present embodiment)

[0538] In the optical device of this embodiment, an additional light guide component can be arranged between the light source and the light guide component.

[0539] Figure 19 This is a diagram illustrating the optical device of this embodiment. Figure 19 (a) is the third example of a diagram showing the internal structure of an optical device. Figure 19 (b) is the fourth example of a diagram showing the internal structure of an optical device. Figure 19 Figure (c) is the fifth example showing the internal structure of the optical device. (Regarding...) Figure 2 (a) The same structures are labeled with the same reference numerals, and the descriptions are omitted.

[0540] In the third case, such as Figure 19 As shown in (a), the optical device 190 includes a light source 11, a lens 191, a light guide member 192, a light guide member 12, and a wavelength conversion member 13.

[0541] Light emitted from light source 11 is focused by lens 191. A light guide member 192 is disposed at the focusing position. Therefore, light emitted from light source 11 can be directed into the light guide member 192.

[0542] Light incident on the light guide member 192 exits from the light guide member 192. Light exiting from the light guide member 192 enters the light guide member 12.

[0543] The light guide member 192 has an incident end face 192a and an exit end face 192b. The diameter of the incident end face 192a is the same as the diameter of the exit end face 192b. The diameter of the exit end face 192b is the same as the diameter of the incident end face 192a.

[0544] Between the incident end face 192a and the exit end face 12b, the diameters of the incident end face 192a, the exit end face 192b, and the incident end face 12a are the largest diameters.

[0545] In the optical device 190, the end face with the largest diameter is located on the side of the light source 11. Therefore, light emitted from the light source 11 can be efficiently directed to the light guide member.

[0546] In the fourth case, such as Figure 19 As shown in (b), the optical device 200 includes a light source 11, a lens 191, a light guide member 201, and a wavelength conversion member 13.

[0547] Light emitted from light source 11 is focused by lens 191. A light guide member 201 is disposed at the focusing position. Therefore, light emitted from light source 11 can be directed into the light guide member 201.

[0548] Light incident on the light guide member 201 exits from the light guide member 201. Light exiting from the light guide member 201 enters the light guide member 202.

[0549] The light guide component 201 has an incident end face 201a and an exit end face 201b. The light guide component 202 has an incident end face 202a and an exit end face 202b.

[0550] The diameter of the incident end face 201a is larger than the diameter of the exit end face 201b. The diameter of the incident end face 202a is larger than the diameter of the exit end face 202b. The diameter of the exit end face 201b is the same as the diameter of the incident end face 202a.

[0551] Between the incident end face 201a and the exit end face 202b, the diameter of the incident end face 201a is the largest.

[0552] In the optical device 200, the end face with the largest diameter is located on the side of the light source 11. Therefore, light emitted from the light source 11 can be efficiently directed to the light guide member.

[0553] In case 5, such as Figure 19 As shown in (c), the optical device 210 includes a light source 11, a lens 191, a light guide member 211, a lens 212, a light guide member 213, and a wavelength conversion member 13.

[0554] Light emitted from light source 11 is focused by lens 191. A light guide member 211 is disposed at the focusing position. Therefore, light emitted from light source 11 can be directed into the light guide member 211.

[0555] Light incident on the light guide member 211 exits from the light guide member 211. The light exiting from the light guide member 211 is focused by the lens 212. A light guide member 213 is arranged at the focusing position. Therefore, light exiting from the light guide member 211 can be directed to the light guide member 213.

[0556] The light guide member 211 has an incident end face 211a and an exit end face 211b. The light guide member 213 has an incident end face 213a and an exit end face 213b.

[0557] The diameter of the incident end face 211a is larger than the diameter of the exit end face 211b. The diameter of the incident end face 213a is larger than the diameter of the exit end face 213b. The diameter of the exit end face 211b is larger than the diameter of the incident end face 213a.

[0558] Between the incident end face 211a and the exit end face 213b, the diameter of the incident end face 211a is the largest.

[0559] In the optical device 210, the end face having the largest diameter is located on the light source 11 side. Therefore, it is possible to efficiently cause the light emitted from the light source 11 to be incident on the light guide member.

[0560] In the optical device of the present embodiment, the light guide member is preferably a tapered optical fiber that is tapered from the incident end face toward the emission end face.

[0561] (Optical device 17 of the present embodiment)

[0562] The wireless endoscope of the present embodiment is characterized by having: an insertion section that is elongated and flexible; and an operation section provided at a rear end of the insertion section, the insertion section having: a front end section provided at a front end of the insertion section; a bending section provided at a rear end of the front end section; and a flexible tube section extending from a rear end of the bending section to a front end of the operation section, a light source being disposed at a position on the operation section side than the rear end of the insertion section, a light conversion member being disposed at the front end section, a light guide member formed of a medium having a refractive index greater than 1 being disposed between the light source and the light conversion member, light emitted from the light source being incident on an incident end face of the light guide member, light emitted from an emission end face of the light guide member being radiated to the light conversion member, the light guide member including a first light guide region having the incident end face and a second light guide region having the emission end face, the incident end face having a diameter greater than a diameter of the emission end face, the first light guide region having a length shorter than a length of the second light guide region, at least a part of the second light guide region being contained in the insertion section.

[0563] Figure 20 is a view that shows a wireless endoscope. The wireless endoscope 300 has a wireless endoscope main body 310 (hereinafter referred to as "main body 310") and a battery 320. The battery 320 is attached (connected) to the main body 310 in a detachable manner.

[0564] The main body 310 has an insertion section 330 and an operation section 340. The insertion section 330 is elongated and flexible. The operation section 340 is provided at a rear end (base end) 330R of the insertion section.

[0565] The insertion section 330 has a front end section 331, a bending section 332, and a flexible tube section 333. The front end section 331 is provided at a front end 330F of the insertion section. The bending section 332 is provided at a rear end 331R of the front end section. The flexible tube section 333 extends from a rear end 332R of the bending section to a front end 340F of the operation section.

[0566] A bending operation knob 341 is provided at the operation section 340. The bending section 332 is bent in the up-down direction and the left-right direction by the bending operation knob 341. Further, a treatment instrument insertion port 342 is provided near the front end 340F of the operation section. A treatment instrument is inserted from the treatment instrument insertion port 342.

[0567] A light source 350 is disposed at a position closer to the operation section 340 than the rear end 330R of the insertion section. A light conversion member 351 is disposed at the front end section 331. A light guide member 352 is disposed between the light source 350 and the light conversion member 351. The light guide member 352 is formed of a medium having a refractive index greater than 1.

[0568] Light emitted from the light source 350 is incident on the incident end surface of the light guide member 352. Light emitted from the emission end surface of the light guide member 352 is irradiated toward the light conversion member 351.

[0569] The light guide member 352 has a first light guide region 352' and a second light guide region 352". The first light guide region 352' has an incident end surface 352a. The second light guide region 352" has an emission end surface 352b.

[0570] The diameter of the incident end surface 352a is greater than the diameter of the emission end surface 352b. The diameter of the second light guide region 352" is equal to the diameter of the emission end surface 352b. The length of the first light guide region 352' is shorter than the length of the second light guide region 352".

[0571] In the wireless endoscope 300, the insertion section 330 is occupied by the second light guide region 352". The diameter of the second light guide region 352" is very small. Therefore, in the wireless endoscope 300, it is possible to make the thickness of the insertion section 330 thin. At least a part of the insertion section 330 is inserted into, for example, a body or a metal pipe. Thus, it is possible to easily insert the insertion section 330.

[0572] Further, the first light guide region 352' is located between the light source 350 and the second light guide region 352". Therefore, it is possible to efficiently cause light emitted from the light source 350 to be incident on the first light guide region 352'.

[0573] Further, it is possible to efficiently cause light incident on the first light guide region 352' to travel from the first light guide region 352' to the second light guide region 352". In this case, since it is possible to irradiate the light conversion member 351 with bright light, it is possible to obtain bright illumination light.

[0574] (Endoscope system of the present embodiment)

[0575] The endoscope system of the present embodiment is characterized by having: the optical device of the present embodiment or the wireless endoscope of the present embodiment; and a processing device.

[0576] As explained in the first example of the optical device (a) of the present embodiment, Figure 1 As explained in the first example of the optical device (a) of the present embodiment, Figure 1As described in (b) of the above, the optical device 4 is connected with the imaging device. Thus, in the optical device 1, the image data acquired by the imaging element can be outputted in a wireless manner. In the optical device 4, the image data acquired by the imaging device can be outputted in a wired manner.

[0577] Thus, the processing device capable of receiving the image data is prepared separately from the optical device. By so doing, the image data can be acquired.

[0578] In the case where the optical device of the present embodiment is an endoscope, by combining various devices, such as the processing device, with the optical device of the present embodiment, an endoscope system can be constructed.

[0579] Industrial Applicability

[0580] The present application is suitable for an optical device, a wireless endoscope, and an endoscope system in which a tubular portion is thin and in which illumination light can be efficiently incident on a light guide member inside the tubular portion.

[0581] Explanation of Reference Numerals

[0582] 1, optical device; 2, holding portion; 3, tubular portion; 4, optical device; 5, holding portion; 6, tubular portion; 7, light source unit; 8, processing device; 9, display device; 10, 14, optical device; 11, light source; 12, light guide member; 12a, incident end face; 12b, exit end face; 12', 15', first light guide region; 12", 15", second light guide region; 12CL, cladding layer; 13, wavelength conversion member; 15, 17, 18, light guide member; 16, diffusion member; 17a, 18a, incident end face; 17b, 18b, exit end face; 20, 30, 40, 50, 60, 70, optical device; 21, 31, 41, 51, 61, 71, holding portion; 22, 32, 42, 52, 62, 72, tubular portion; 23, 33, 43, 53, 63, front end portion; 24, 34, 44, 54, 64, base end portion; 25, 35, operation portion; 26, 36, intermediate portion; 45, imaging device; 73, first tubular portion; 74, second tubular portion; 75, first front end portion; 76, first base end portion; 77, second front end portion; 78, second base end portion; 79, connecting portion; 80, light source unit; 90, 95, 100, 105, wavelength conversion unit; 91, 96, 101, 106, holding member; 92, 97, 102, 107, reflecting member; 102a, reflecting surface; 93, 103, wavelength conversion member; 94, 98, 104, 108, light guide member; 110, 120, optical device; 111, optical coupler; 112, core; 113, cladding layer; 114, 115, incident portion; 116, 117, exit portion; 118, light guide member; 118CL, cladding layer; 118', first light guide region; 118", second light guide region; 118a, incident end face; 118, 119, 121, 122, light source; 130, 140, 150, optical device; 131, 141, 142, 151, 152, pair of optical connectors; 132, 133, 143, 144, 145, 146, 153, 154, 155, 156, optical connector; 134, 135, light guide member; 134CL, 135CL, cladding layer; 136, 138, optical fiber; 137, 139, holding member; 160, 170, 180, optical device; 161, housing; 162, lens; 171, 181, first housing; 172, 182, second housing; 183, 184, optical connector; 190, 200, 210, optical device; 191, 212, lens; 192, 201, 202, 211, 213, light guide member; 192a, 201a, 202a, 211a, 213a, incident end face; 192b, 201b, 202b, 211b, 213b, exit end face; 300, wireless endoscope; 310, wireless endoscope body; 320, battery; 330, insertion portion;330F, front end of the insertion section; 330R, rear end (base end) of the insertion section; 331, front end portion; 331R, rear end of the front end portion; 332, curved portion; 332R, rear end of the curved portion; 333, flexible tube portion; 340, operation portion; 340F, front end of the operation portion; 341, curved operation knob; 342, treatment instrument insertion port; 350, light source; 351, light conversion member; 352, light guide member; 352', first light guide region; 352", second light guide region; 352a, incident end surface; 352b, exit end surface; L1, light of the first wavelength region; L2, light of the second wavelength region; L3, L5, illumination light; L4, L6, fluorescent light; LBS, LBL, light beam; Ri, incident end surface; Ro, exit end surface; ADP, light adapter.

Claims

1. An endoscope characterized by comprising: an elongated insertion section; an operation section provided at a position on a proximal side of the insertion section; and a light guide member that penetrates through the insertion section, the light guide member includes a first light guide region provided on a proximal side in the light guide member and having an incidence end surface on which light from a light source is incident, and a second light guide region provided on a distal side of the first light guide region and having an emission end surface from which the light is emitted, a diameter of the first light guide region decreases toward the second light guide region, a length of the first light guide region is shorter than a length of the second light guide region, a diameter of the incidence end surface of the first light guide region is larger than a diameter of the second light guide region, and at least a part of the second light guide region is included in the insertion section, the endoscope includes: a light conversion member provided in the insertion section, the light emitted from the light source is incident on the incidence end surface of the light guide member and is irradiated on the light conversion member from the emission end surface of the light guide member, the endoscope satisfies the following conditional expression (1): LEF1 < ΔEF (1) wherein LEF1 is a light coupling efficiency of the light guide member and is expressed by LEF1 = Iout / Iin, ΔEF is a difference in conversion efficiency of the light conversion member and is expressed by ΔEF = |EFa - EFb|, Iout is an intensity of the light incident on the incidence end surface, Iin is an intensity of the light emitted from the emission end surface, EFa is a conversion efficiency when a diameter of the emission end surface is φa, EFb is a conversion efficiency when a diameter of the emission end surface is φb, the conversion efficiency is expressed by Q / P, P is an intensity of the light irradiated on the light conversion member, Q is an intensity of the light emitted from the light conversion member, φa is the diameter of the incidence end surface, φb is the diameter of the emission end surface.

2. The endoscope according to claim 1, characterized in that the first light guide region is provided in the operation section.

3. The endoscope according to claim 1, characterized in that the first light guide region is in a frustoconical shape that becomes thinner toward the second light guide region.

4. The endoscope according to claim 1, characterized in that the second light guide region is provided throughout the insertion section, a diameter of the light guide member in the second light guide region is constant up to the emission end surface.

5. The endoscope according to claim 1, characterized in that the endoscope has a first housing and a second housing, the light source is disposed in the first housing, the light guide member and the light conversion member are disposed in the second housing, the first housing and the second housing are independent of each other.

6. The endoscope according to claim 1, characterized in that a light coupler is disposed between the light source and the light guide member, the light coupler has a core and a cladding, a diameter of the core is the same as a diameter of the incidence end surface.

7. The endoscope according to claim 1, characterized in that a pair of optical connectors is disposed between the light source and the light guide member, ​ The optical connector has an optical connector light guide member and a holding member, The diameter of the optical connector light guide member is the same as the diameter of the incident end face.

8. The endoscope according to claim 7, wherein The endoscope has a housing having a holding portion and a tubular portion, The light source, the pair of optical connectors, the light guide member, and the light conversion member are disposed in the housing.

9. The endoscope according to claim 7, wherein The endoscope has a first housing and a second housing, The first housing has one of the optical connectors, The second housing has the other of the optical connectors.

10. An endoscope comprising: An elongated insertion portion; An operation portion provided at a position on a proximal side of the insertion portion; and A light guide member that penetrates through the insertion portion, The light guide member includes a first light guide region provided on a proximal side in the light guide member and having an incident end face at which light from a light source is incident, and a second light guide region provided on a distal side of the first light guide region and having an exit end face at which the light exits, The diameter of the first light guide region decreases toward the second light guide region, The length of the first light guide region is shorter than the length of the second light guide region, the diameter of the incident end face of the first light guide region is larger than the diameter of the second light guide region, and at least a part of the second light guide region is included in the insertion portion, The endoscope includes: A light conversion member provided in the insertion portion, The light emitted from the light source is incident on the incident end face of the light guide member and is irradiated on the light conversion member from the exit end face of the light guide member, The light conversion member is a wavelength conversion member, Light in a first wavelength region is emitted from the light source, Light in a second wavelength region is generated from the light in the first wavelength region by the wavelength conversion member, Light having a wavelength longer than that of the light in the first wavelength region is included in the light in the second wavelength region, The endoscope satisfies the following conditional expression (1'): LEF1 < ΔEF' (1') Here, LEF1 is the light coupling efficiency of the light guide member and is expressed by LEF1 = Iout / Iin, ΔEF' is the difference in conversion efficiency of the wavelength conversion member and is expressed by ΔEF' = |EFa' - EFb'|, Iout is the intensity of the light incident on the incident end face, Iin is the intensity of the light emitted from the exit end face, EFa' is the conversion efficiency when the diameter of the exit end face is φa, EFb' is the conversion efficiency when the diameter of the exit end face is φb, The conversion efficiency is expressed by Q' / P', P' is the intensity of the light in the first wavelength region irradiated on the wavelength conversion member, Q' is the intensity of the light in the second wavelength region or the sum of the intensity of the light in the second wavelength region and the intensity of the light in the first wavelength region transmitted through the wavelength conversion member, φa is the diameter of the incident end face, φb is the diameter of the exit end face.

11. An endoscope comprising: An elongated insertion portion; ​ ​ an operation section provided at a position closer to the base end side than the insertion section; and a light guide member that penetrates within the insertion section, the light guide member includes: a first light guide region provided at the base end side in the light guide member and having an incident end surface at which light from a light source is incident; and a second light guide region provided at the front end side of the first light guide region and having an emission end surface at which the light is emitted, a diameter of the first light guide region decreases as it goes toward the second light guide region, a length of the first light guide region is shorter than a length of the second light guide region, a diameter of the incident end surface of the first light guide region is larger than a diameter of the second light guide region, and at least a part of the second light guide region is included in the insertion section, the endoscope includes: a light conversion member provided at the insertion section, light emitted from the light source is incident on the incident end surface of the light guide member and is emitted from the emission end surface of the light guide member to the light conversion member, the endoscope satisfies the following conditional expression (2): (φa / φb) 2 ×(NAa / NAb) 2 <1 / 2+(1 / 2)×{(φb / (2×d)) 2 +1} －1 / 2 (2) Here, φa is a diameter of the incident end surface, φb is a diameter of the emission end surface, NAa is a numerical aperture of the incident end surface, NAb is a numerical aperture of the emission end surface, d is a distance from the emission end surface to the light conversion member.

12. An endoscope characterized by comprising: an elongated insertion section; an operation section provided at a position closer to the base end side than the insertion section; and a light guide member that penetrates within the insertion section, the light guide member includes: a first light guide region provided at the base end side in the light guide member and having an incident end surface at which light from a light source is incident; and a second light guide region provided at the front end side of the first light guide region and having an emission end surface at which the light is emitted, a diameter of the first light guide region decreases as it goes toward the second light guide region, a length of the first light guide region is shorter than a length of the second light guide region, a diameter of the incident end surface of the first light guide region is larger than a diameter of the second light guide region, and at least a part of the second light guide region is included in the insertion section, the endoscope includes: a light conversion member provided at the insertion section, light emitted from the light source is incident on the incident end surface of the light guide member and is emitted from the emission end surface of the light guide member to the light conversion member, the light conversion member is a wavelength conversion member, the endoscope satisfies the following conditional expression (2'): Here, (φa / φb) 2 ×(NAa / NAb) 2 <1 / 2+(1 / 2)×{(φb / (2×d')) 2 +1} －1 / 2 (2’) φa is a diameter of the incident end surface, φb is a diameter of the emission end surface, NAa is a numerical aperture of the incident end surface, NAb is a numerical aperture of the emission end surface, d' is a distance from the emission end surface to the wavelength conversion member.

13. An endoscope characterized by comprising: an elongated insertion section; an operation section provided at a position closer to the base end side than the insertion section; and a light guide member that penetrates within the insertion section, ​ ​ The light guide member includes a first light guide region provided at a proximal end side in the light guide member and having an incident end surface on which light from a light source is incident, and a second light guide region provided at a distal end side of the first light guide region and having an emission end surface from which the light is emitted, The diameter of the first light guide region decreases toward the second light guide region, The first light guide region is shorter in length than the second light guide region, the diameter of the incident end surface of the first light guide region is larger than the diameter of the second light guide region, and at least a part of the second light guide region is included in the insertion portion, The endoscope includes: a light conversion member provided in the insertion portion, light emitted from the light source is incident on the incident end surface of the light guide member and is irradiated from the emission end surface of the light guide member to the light conversion member, a light coupler is provided between the light source and the light guide member, the light coupler has a core and a cladding, the diameter of the core is the same as the diameter of the incident end surface, the endoscope satisfies the following conditional expression (3): LEF1cou < ΔEF (3) Here, LEF1cou = LEF1 + ΔLEFcou LEF1 is the light coupling efficiency of the light guide member and is expressed by LEF1 = Iout / Iin, ΔLEFcou is the difference in the light coupling efficiency of the light coupler and is expressed by ΔLEFcou = |LEFcoua - LECoub|, Iout is the intensity of light incident on the incident end surface, Iin is the intensity of light emitted from the emission end surface, LEFcoua is the light coupling efficiency when the diameter of the core is φa, LEFcoub is the light coupling efficiency when the diameter of the core is φb, ΔEF is the difference in the conversion efficiency of the light conversion member and is expressed by ΔEF = |EFa - EFb|, EFa is the conversion efficiency when the diameter of the emission end surface is φa, EFb is the conversion efficiency when the diameter of the emission end surface is φb, the conversion efficiency is expressed by Q / P, P is the intensity of light irradiated to the light conversion member, Q is the intensity of light radiated from the light conversion member, φa is the diameter of the incident end surface, φb is the diameter of the emission end surface.

14. An endoscope characterized by the endoscope includes: an elongated insertion portion; an operation portion provided at a position on the proximal end side of the insertion portion; and a light guide member that penetrates through the insertion portion, the light guide member includes a first light guide region provided at a proximal end side in the light guide member and having an incident end surface on which light from a light source is incident, and a second light guide region provided at a distal end side of the first light guide region and having an emission end surface from which the light is emitted, the diameter of the first light guide region decreases toward the second light guide region, the first light guide region is shorter in length than the second light guide region, the diameter of the incident end surface of the first light guide region is larger than the diameter of the second light guide region, and at least a part of the second light guide region is included in the insertion portion, the endoscope includes: a light conversion member provided in the insertion portion, light emitted from the light source is incident on the incident end surface of the light guide member and is irradiated from the emission end surface of the light guide member to the light conversion member, light emitted from the light source is incident on the incident end surface of the light guide member, and is irradiated from the emission end surface of the light guide member to the light conversion member, a light coupler is arranged between the light source and the light guide member, the light coupler has a core and a clad, the diameter of the core is the same as the diameter of the incident end surface, the light conversion member is a wavelength conversion member, light of a first wavelength region is emitted from the light source, light of a second wavelength region is generated from the light of the first wavelength region by the wavelength conversion member, light of a wavelength longer than that of the light of the first wavelength region is included in the light of the second wavelength region, the endoscope satisfies the following conditional expression (3'): LEF1cou < ΔEF' (3') Here, LEF1cou = LEF1 + ΔLEFcou LEF1 is the light coupling efficiency of the light guide member, and is expressed by LEF1 = Iout / Iin, ΔLEFcou is the difference in the light coupling efficiency of the light coupler, and is expressed by ΔLEFcou = |LEFcoua - LECoub|, Iout is the intensity of light incident on the incident end surface, Iin is the intensity of light emitted from the emission end surface, LEFcoua is the light coupling efficiency when the diameter of the core is φa, LEFcoub is the light coupling efficiency when the diameter of the core is φb, ΔEF' is the difference in the conversion efficiency of the wavelength conversion member, and is expressed by ΔEF' = |EFa' - EFb'|, EFa' is the conversion efficiency when the diameter of the emission end surface is φa, EFb' is the conversion efficiency when the diameter of the emission end surface is φb, the conversion efficiency is expressed by Q' / P', P' is the intensity of the light of the first wavelength region irradiated to the wavelength conversion member, Q' is the intensity of the light of the second wavelength region or the sum of the intensity of the light of the second wavelength region and the intensity of the light of the first wavelength region transmitted through the wavelength conversion member, φa is the diameter of the incident end surface, φb is the diameter of the emission end surface.

15. An endoscope characterized by the endoscope includes: an elongated insertion section; an operation section provided at a position on a proximal side of the insertion section; and a light guide member that penetrates within the insertion section, the light guide member includes: a first light guide region provided on a proximal side in the light guide member and having an incident end surface on which light from a light source is incident; and a second light guide region provided on a distal side of the first light guide region and having an emission end surface from which the light is emitted, the diameter of the first light guide region decreases as it goes toward the second light guide region, the length of the first light guide region is shorter than the length of the second light guide region, the diameter of the incident end surface of the first light guide region is larger than the diameter of the second light guide region, and at least a part of the second light guide region is included in the insertion section, the endoscope includes: a light conversion member provided in the insertion section, light emitted from the light source is incident on the incident end surface of the light guide member, and is irradiated from the emission end surface of the light guide member to the light conversion member, a pair of optical connectors is arranged between the light source and the light guide member, The optical connector has an optical connector light guide member and a holding member, The diameter of the optical connector light guide member is the same as the diameter of the incident end face, The endoscope satisfies the following conditional expression (4): LEF1cne < ΔEF (4) Here, LEF1cne = LEF1 + ΔLEFcne LEF1 is the light coupling efficiency of the light guide member, and is expressed by LEF1 = Iout / Iin, ΔLEFcne is the difference in the light coupling efficiency of the optical connector, and is expressed by ΔLEFcne = |LEFcnea - LEFcneb|, Iout is the intensity of light incident on the incident end face, Iin is the intensity of light emitted from the exit end face, LEFcnea is the light coupling efficiency when the diameter of the optical connector light guide member is φa, LEFcneb is the light coupling efficiency when the diameter of the optical connector light guide member is φb, ΔEF is the difference in the conversion efficiency of the light conversion member, and is expressed by ΔEF = |EFa - EFb|, EFa is the conversion efficiency when the diameter of the exit end face is φa, EFb is the conversion efficiency when the diameter of the exit end face is φb, The conversion efficiency is expressed by Q / P, P is the intensity of light irradiated on the light conversion member, Q is the intensity of light emitted from the light conversion member, φa is the diameter of the incident end face, φb is the diameter of the exit end face.

16. An endoscope characterized by The endoscope includes: an elongated insertion section; an operation section provided at a position on a proximal side of the insertion section; and a light guide member that penetrates within the insertion section, The light guide member includes: a first light guide region provided on a proximal side in the light guide member and having an incident end face on which light from a light source is incident; and a second light guide region provided on a distal side of the first light guide region and having an exit end face from which the light is emitted, The diameter of the first light guide region decreases toward the second light guide region, The length of the first light guide region is shorter than the length of the second light guide region, the diameter of the incident end face of the first light guide region is larger than the diameter of the second light guide region, and at least a part of the second light guide region is included in the insertion section, The endoscope includes: a light conversion member provided in the insertion section, light emitted from the light source is incident on the incident end face of the light guide member and irradiated on the light conversion member from the exit end face of the light guide member, a pair of optical connectors is arranged between the light source and the light guide member, The optical connector has an optical connector light guide member and a holding member, The diameter of the optical connector light guide member is the same as the diameter of the incident end face, The light conversion member is a wavelength conversion member, light of a first wavelength region is emitted from the light source, light of a second wavelength region is generated from the light of the first wavelength region by the wavelength conversion member, light having a longer wavelength than the light of the first wavelength region is included in the light of the second wavelength region, The endoscope satisfies the following conditional expression (4'): LEF1cne < ΔEF' (4') Here, LEF1cne = LEF1 + ΔLEFcne LEF1 is a light coupling efficiency of the light guide member, and is expressed by LEF1 = Iout / Iin, ΔLEFcne is a difference in light coupling efficiency of the optical connector, and is expressed by ΔLEFcne = |LEFcnea - LEFcneb|, Iout is an intensity of light incident to the incident end surface, Iin is an intensity of light emitted from the emission end surface, LEFcnea is a light coupling efficiency when the diameter of the light guide member of the optical connector is φa, LEFcneb is a light coupling efficiency when the diameter of the light guide member of the optical connector is φb, ΔEF' is a difference in conversion efficiency of the wavelength conversion member, and is expressed by ΔEF' = |EFa' - EFb'|, EFa' is a conversion efficiency when the diameter of the emission end surface is φa, EFb' is a conversion efficiency when the diameter of the emission end surface is φb, the conversion efficiency is expressed by Q' / P', P' is an intensity of light of the first wavelength region irradiated to the wavelength conversion member, Q' is an intensity of light of the second wavelength region or a sum of an intensity of light of the second wavelength region and an intensity of light of the first wavelength region transmitted through the wavelength conversion member, φa is a diameter of the incident end surface, φb is a diameter of the emission end surface.

17. An endoscope system characterized by the endoscope system includes an endoscope and a light source for supplying light to the endoscope, the endoscope includes an elongated insertion section, an operation section provided at a position on a proximal end side of the insertion section, and a light guide member that penetrates within the insertion section, the light guide member includes: a first light guide region provided on a proximal end side in the light guide member and having an incident end surface at which light from the light source is incident, and a second light guide region provided on a distal end side of the first light guide region and having an emission end surface at which the light is emitted, a diameter of the first light guide region decreases toward the second light guide region, a length of the first light guide region is shorter than a length of the second light guide region, a diameter of the incident end surface of the first light guide region is larger than a diameter of the second light guide region, and at least a part of the second light guide region is included in the insertion section, the endoscope includes: a light conversion member provided in the insertion section, light emitted from the light source is incident to the incident end surface of the light guide member and is irradiated to the light conversion member from the emission end surface of the light guide member, the endoscope satisfies the following conditional expression (1): LEF1 < ΔEF (1) Here, LEF1 is a light coupling efficiency of the light guide member, and is expressed by LEF1 = Iout / Iin, ΔEF is a difference in conversion efficiency of the light conversion member, and is expressed by ΔEF = |EFa - EFb|, Iout is an intensity of light incident to the incident end surface, Iin is an intensity of light emitted from the emission end surface, EFa is a conversion efficiency when the diameter of the emission end surface is φa, EFb is a conversion efficiency when the diameter of the emission end surface is φb, the conversion efficiency is expressed by Q / P, P is an intensity of light irradiated to the light conversion member, Q is an intensity of light emitted from the light conversion member, φa is a diameter of the incident end surface, φb is a diameter of the exit end surface.

18. An endoscope characterized by comprising: the endoscope comprising: an elongated insertion section having flexibility; an operation section provided at a position on a proximal side of the insertion section; and a light guide member that penetrates through the insertion section, the light guide member comprising: a second light guide region provided throughout a full length in the insertion section, the second light guide region having an exit end surface at a front end surface thereof that exits light from a light source; and a first light guide region provided on a proximal side of the second light guide region and having a diameter that expands from a proximal end of the second light guide region, the first light guide region having an incident end surface at a proximal end surface thereof that receives light from the light source, the endoscope comprising: a light conversion member provided in the insertion section, light exited from the light source is incident to an incident end surface of the light guide member and is irradiated to the light conversion member from an exit end surface of the light guide member, the endoscope satisfies the following conditional expression (1): LEF1 < ΔEF (1) Herein, LEF1 is a light coupling efficiency of the light guide member, expressed by LEF1 = Iout / Iin, ΔEF is a difference in conversion efficiency of the light conversion member, expressed by ΔEF = |EFa - EFb|, Iout is an intensity of light incident to the incident end surface, Iin is an intensity of light exited from the exit end surface, EFa is a conversion efficiency when the diameter of the exit end surface is φa, EFb is a conversion efficiency when the diameter of the exit end surface is φb, the conversion efficiency is expressed by Q / P, P is an intensity of light irradiated to the light conversion member, Q is an intensity of light emitted from the light conversion member, φa is a diameter of the incident end surface, φb is a diameter of the exit end surface.

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