Insertion instrument

1 . An insertion instrument, comprising:

an insertion portion; and

an operation portion located proximally relative to the insertion portion,

wherein the operation portion includes:

a housing having an exterior body,

a heat sink block located inside the exterior body,

a substrate with a light emission body arranged to make contact with one surface of the heat sink block, and

a conduit for a fluid, and

wherein the conduit includes:

a first portion located outside the exterior body, and

a second portion located inside the exterior body and in contact with an outer surface of the heat sink block.

2 . The insertion instrument according to claim 1 , wherein an outer surface of the second portion of the conduit is in contact with the heat sink block.

3 . The insertion instrument according to claim 2 , wherein a surface of the exterior body facing toward an interior of the housing includes a seating surface, and

wherein the heat sink block and the second portion of the conduit are located in the seating surface with the second portion of the conduit located between a surface of the seating surface and a portion of the heat sink block.

4 . The insertion instrument according to claim 1 , further comprising a light guide,

wherein the light guide transmits light from the light emission body to a light emission window of the insertion portion, and

wherein a proximal end portion of the light guide is attached to the heat sink block.

5 . The insertion instrument according to claim 4 , wherein the light emission body and the light guide are attached to the heat sink block with the light emission body facing the proximal end of the light guide.

6 . The insertion instrument according to claim 5 , wherein the conduit is in contact with two or more surfaces of the heat sink block.

7 . The insertion instrument according to claim 5 , wherein the outer surface of the heat sink block includes a groove, and

wherein the conduit is seated in the groove.

8 . The insertion instrument according to claim 7 , wherein the groove extends over only a portion of an outer surface of the second portion of the conduit.

9 . The insertion instrument according to claim 4 , wherein the light guide includes one or more optical fibers.

10 . The insertion instrument according to claim 9 , wherein the light emission body includes a light emitting diode or a semiconductor laser.

11 . The insertion instrument according to claim 1 , wherein the conduit further includes a third portion,

wherein the third portion is formed by a channel in a body of the heat sink block, the heat sink block having a first connecting portion at a first end of the channel and a second connecting portion at a second end of the channel, and

wherein third second portion of the conduit is located between the first portion and the third portion and connected to the first connecting portion and the second connecting portion.

12 . The insertion instrument according to claim 1 , wherein the exterior body includes:

a first operation section,

a second operation section including a handhold configured for grasping by an operator, and

a plurality of vent holes providing a ventilation path from inside the housing to outside the housing,

wherein the plurality of vent holes is located in at least one of (i) the first operation section and (ii) a portion of the second operation section other than the handhold, and

wherein the housing includes an angle lever configured to operate the insertion portion, the angle lever located in the first operation section.

13 . The insertion instrument according to claim 1 , wherein the heat sink block covers a part of an outer surface of the second portion of the conduit.

14 . The insertion instrument according to claim 1 , wherein the light emission body includes one or more light emitting diodes, and

wherein the second portion of the conduit contacts the light emitting diodes.

15 . The insertion instrument according to claim 1 , wherein the insertion instrument is an endoscope, and

wherein the endoscope is configured to continuously circulate the fluid between an inside of a subject and an outside of the subject.

16 . The insertion instrument according to claim 15 , wherein the conduit is a flow path to supply the fluid to the inside of the subject,

wherein the insertion instrument further comprises a suction tube configured to suction the fluid from the inside of the subject to the outside of the subject, and

wherein a first portion of the suction tube is located in the exterior body of the housing, and at least a part of the first portion of the suction tube contacts the outer surface of the heat sink block.

17 . The insertion instrument according to claim 1 , further comprising a base plate attached to the substrate,

wherein the second portion of the conduit contacts the base plate.

18 . The insertion instrument according to claim 1 , wherein the second portion of the conduit is a tube arranged to contact the outer surface of the heat sink block.

19 . The insertion instrument according to claim 1 , wherein the substrate is attached to the heat sink block so that the light emission body is positioned opposite to the one surface of the heat sink block.

20 . The insertion instrument according to claim 19 , wherein the heat sink block is provided with a recess on the one surface, and the light emission body is arranged in the recess.