JP2006263234A - Endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve an endoscope with two curves, which prevents housed components from being buckled and damaged by contact. <P>SOLUTION: The endoscope of the present invention includes an insertion part 11 wherein a first curve 24 and a second curve 25 are installed in order from the end point to the base point. Furthermore, the endoscope includes a first protection tube 111a which is installed so as to cover the housed components inserted through the inside of the insertion part 11 across an area of the first curve 24 and the second curve 25 in an axial direction of the insertion part 11 and has a first hardness, and a second protection tube 111b which is subsequently installed on a base point of the first protection tube so as to cover the housed components and has a second hardness lower than the first one. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an endoscope, and more particularly to an endoscope having two curved portions.

  In recent years, endoscopes are widely used in the medical field and the industrial field. An endoscope, particularly an endoscope with a flexible insertion portion, can be inserted into a bent machine or the like, or into a gastrointestinal or other body cavity. Endoscopes need to bend three-dimensionally in a flexible manner so that an elongated insertion part can be inserted along the shape of a thin lumen that is bent three-dimensionally and complicatedly. is there.

Therefore, for example, there are two locations: a first bending portion in which a plurality of joint pieces are rotatably connected to the distal end side of the elongated insertion portion, and a second bending portion that is connected to the proximal end side of the first bending portion. An endoscope has been proposed in which a bending portion is provided continuously with a distal end portion of a flexible flexible tube portion (see, for example, Patent Document 1).
JP 2003-93330 A

  However, various built-in objects such as a light guide, an air / water channel channel, and a signal line from the image sensor are inserted into the two curved portions. Since the two bending portions are independently bent, there is a problem of damage due to buckling of the built-in objects and contact between the built-in objects.

  Specifically, for example, when the bending direction in the first bending portion and the bending direction in the second bending portion are opposite directions, the built-in object positioned on the inner diameter side of the bending radius of the bending portion of the first bending portion is the first. The force pushed out from the bending portion to the second bending portion works, but the built-in object has a force pushed out from the second bending portion toward the first bending portion in the second bending portion, so these two forces are When they collide, there was a possibility that a compressive force was generated in the built-in object and buckled. Furthermore, since this compressive force applies a large force in the radial direction when the built-in object moves in the radial direction in the two curved portions, the built-in objects are pressed with a strong force or the built-in object is inserted. Since the inner wall of the portion is pressed with a strong force, the built-in object may be damaged due to contact at that time.

  Therefore, the present invention has been made in view of the above circumstances, and provides an endoscope in which a built-in object is not buckled or damaged by contact in an endoscope having two curved portions. For the purpose.

  The endoscope of the present invention is an endoscope having an insertion portion in which a first bending portion and a second bending portion are provided in order from a distal end portion toward a proximal end portion, in the axial direction of the insertion portion. A first protective tube having a first hardness provided to cover a built-in object inserted inside the insertion portion over a range of the first bending portion and the second bending portion; A second protective tube that is connected to the base end of the first protective tube, covers the built-in object, and has a second hardness lower than the first hardness.

  In an endoscope having two curved portions, it is possible to realize an endoscope in which a built-in object is not buckled or damaged by contact.

Hereinafter, the present invention will be described with reference to the drawings by embodiments.
(First embodiment)
FIG. 1 is a configuration diagram showing an overall configuration of an endoscope apparatus including an endoscope according to the first embodiment of the present invention. As shown in FIG. 1, an endoscope apparatus 1 includes an electronic endoscope (hereinafter simply referred to as an endoscope) 2 having an imaging unit (not shown), a light source device 3, a video processor 4, and a monitor 5. Mainly composed. The light source device 3 is detachably connected to the endoscope 2 and supplies illumination light to the endoscope 2. The video processor 4 is detachably connected to the endoscope 2, controls the imaging unit of the endoscope 2, processes a signal obtained from the imaging unit, and outputs a standard video signal. The monitor 5 displays an endoscopic image obtained by signal processing by the video processor 4 on the screen. The video processor 4 can be connected to a VTR deck, a video printer, a video disk, an image file recording device, etc. (not shown).

  The endoscope 2 is provided with an elongated insertion portion 11 to be inserted into an observation target portion, and an operation portion that is connected to a proximal end portion of the insertion portion 11 and can perform bending operations of first and second bending portions to be described later. A universal cord 13, which is a cord portion that includes a grip portion 12 having 12 a, a cord portion that extends from a side surface of the grip portion 12 and that is connected to an imaging unit (not shown), a light guide that transmits illumination light, and the like. A connector portion 14 is provided at an end portion of the universal cord 13 and is detachably connected to the light source device 3 and the video processor 4.

  The insertion portion 11 is provided with a distal end portion 21 provided at the distal end, a bendable bending portion 22 provided at the proximal end portion of the distal end portion 21, and a proximal end portion of the bending portion 22. A long and flexible flexible tube portion 23 formed from the above members is sequentially provided from the tip.

  The distal end 21 is an imaging unit in which a solid-state imaging device (not shown) such as a CCD as an imaging unit and a circuit board for driving the solid-state imaging device are incorporated, or illumination for illuminating an observation target site in a body cavity. It has a built-in light guide (not shown) that transmits light. The configuration of the tip portion 21 will be described later.

  The bending portion 22 is composed of two bending portions, that is, a distal-end-side bending portion (hereinafter referred to as a first bending portion) 24 and a proximal-end-side bending portion (hereinafter referred to as a second bending portion) 25. Yes.

  A first bending operation for performing the bending operation of the first bending portion 24 so that the first bending portion 24 and the second bending portion 25 can be independently bent on the operation portion 12a of the grip portion 12. A portion 42 and a second bending operation portion 44 for performing a bending operation of the second bending portion 25 are provided. The first bending operation section 42 includes a first bending operation knob 42a for performing bending operations in four directions, up, down, left and right, and a first fixing lever 42b for fixing the first bending operation knob 42a at a desired rotational position. Have The second bending operation unit 44 includes a second bending operation knob 44a for performing bending operations in four directions, up, down, left and right, and a second fixing lever 44b for fixing the second bending operation knob 44a at a desired rotational position. Have

  The operation unit 12a includes an electric switch unit 43 provided with a remote switch for instructing the video processor 4 to freeze or release an observation image, and for operations such as air supply, water supply, and suction. The operation buttons 45 are also provided.

  FIG. 2 is an external view of the distal end side of the insertion portion 11. As shown in FIG. 2, the bending part 22 of the insertion part 11 of this Embodiment is comprised so that two bending parts can be bent independently. The insertion portion 11 includes a distal end portion 21, a first bending portion (front bending portion) 24, a connection portion 22 a, a second bending portion (rear bending portion) 25, and a flexible tube portion 23. Are formed sequentially from the base end side toward the base end side. The connecting portion 22 a is a portion that connects the first bending portion 24 and the second bending portion 25.

  The first bending portion 24 and the second bending portion 25 are each composed of a plurality of bending pieces. The surgeon operates the first bending operation knob 42a and the second bending operation knob 44a of the operation unit 2 of the operation unit 12a, and the wire connected to the bending piece is pulled or loosened, so that it is shown in FIG. Thus, the 1st bending part 24 and the 2nd bending part 25 can each be bent in a desired direction.

  FIG. 3 is a cross-sectional view showing the configuration of the distal end portion 21 of the insertion portion 11. The tip portion 21 has a tip portion main body 51 made of metal such as stainless steel, and the tip portion main body 51 is made of an electrically insulating material such as polysulfone that covers the tip surface and the tip side outer peripheral surface of the tip portion main body 51. An insulating cover 52 is fitted.

  As shown in FIG. 3, the distal end main body 51 is provided with an imaging unit IPU, two light guides LG1, LG2, an air / water supply nozzle portion P, and the like, and various built-in items are provided in the curved portion 22. Is inserted. The cap-shaped insulating cover 52 is provided with a plurality of holes for exposing the imaging unit IPU, the light guides LG1 and LG2, nozzles, and the like from the distal end surface of the distal end portion 21. Here, the diameter of the light guide LG1 is larger than that of the light guide LG2.

  The imaging unit IPU includes an objective lens unit 61, a solid-state imaging device such as a CCD and a circuit unit 62 including a circuit thereof, and a signal line unit 63 connected to the circuit unit 62. Each of the light guides LG1 and LG2 includes illumination lens portions 71 and 81 and fiber portions 72 and 82 in which a plurality of optical fibers are bundled. Accordingly, in the first bending portion 24 and the second bending portion 25 that are bent in various directions, the signal line portion 63 of the imaging unit IPU, the fiber portions 72 and 82 of the light guides LG1 and LG2, and the nozzles are included as built-in objects. The connected channel tube 91 is inserted. Therefore, when the bending portion 22 bends in various directions, the bending portion 22 is easily buckled due to the compressive force applied to the built-in objects, or is easily damaged by pressing the built-in objects with a strong force. Therefore, in this embodiment, the built-in object is covered and protected by a member having a relatively high hardness at the two curved portions.

  Hereinafter, as a built-in object, the fiber part 82 of the light guide LG2 is taken as an example to describe the configuration for protecting the built-in object with a protective member. The fiber portion 72 of LG1 and the channel tube 91 of the nozzle can be protected by the same configuration.

  FIG. 4 is a cross-sectional view showing the configuration of the built-in fiber portion 82 and a protective member that protects the fiber portion 82. A cylindrical metallic base 101 is provided at the tip of the fiber part 82, and a bundle 83 of thin optical fibers is fitted inside the base 101. It is arranged so that the end surface of the front end portion of the bundle 83 of optical fibers fitted into the base 101 faces and abuts against the illumination lens portion 81 (see FIG. 3) provided at the front end portion of the light guide LG2. .

  The optical fiber bundle 83 is covered with the silicon tube 110 over the entire axial direction. That is, the bundle 83 of the plurality of optical fibers is bundled by the silicon tube 110 so as not to be separated. The distal end portion of the silicon tube 110 covers a part of the proximal end portion of the base 101.

  Furthermore, a tube-shaped bending portion protection member 111 is provided so as to cover the fiber portion 82 from the base end portion of the base 101 to the inner side of the distal end portion of the flexible tube portion 23. The distal end portion of the bending portion protection member 111 is covered so as to cover the circumferential convex portion provided on the outer peripheral portion of the base 101, and the outer peripheral surface 111d of the distal end portion of the bending portion protection member 111 is subjected to a thread binding process. And it is fixed to the base end of the base 101 by applying an adhesive. The proximal end portion of the bending portion protection member 111 covers the fiber portion 82 over a predetermined length up to the inner side of the distal end portion of the flexible tube portion 23. Therefore, the bending portion protection member 111 covers the fiber portion 82 that is a built-in object over at least a range of the first bending portion 24 and the second bending portion 25 inside the insertion portion 11.

  Specifically, the bending portion protection member 111 is made of a fluorine resin, for example, tetrafluorofluoroethylene, and is configured by two cylindrical protection tubes 111a and 111b. The first protective tube 111a is a solid (non-porous) fluorine resin, such as Teflon (registered trademark), which is a relatively hard material. The second protective tube 111b is a porous fluororesin, such as Gore-Tex (registered trademark), which is a softer material than the first protective tube 111a, that is, a material having a hardness lower than that of the first protective tube 111a. Etc. The second protective tube 111b, which is softer than the first protective tube 111a, flexes flexibly in response to the curvature of the first curved portion 24 and the second curved portion 25, and the relatively hard first portion 111a is moderate. It has sufficient rigidity to protect the built-in items. In other words, the first protective tube having flexibility lower than that of the built-in fiber portion 82, that is, harder than the fiber portion 82 is provided in the first bending portion 24 and the second bending portion 25. Protect internals.

  The gap d between the inner peripheral surface of each protective tube 111a, 111b and the outer peripheral surface of the silicon tube 110 is a distance of about 0.1 mm.

  As shown by a dotted line in FIG. 2, the first protective tube 111 a extends from the base 101 to the flexible tube portion so as to cover the fiber portion 82 over at least a certain range of the first bending portion 24 and the second bending portion 25. 23 is covered up to the inner side of the back of the tip portion. As shown in FIG.2 and FIG.4, the front end surface of the 1st protection tube 111a is located in the approximate center part of the nozzle | cap | die 101. FIG. And the base end surface of the 1st protection tube 111a is located in the inner side part of the front-end | tip part of the flexible tube part 23. FIG. In the axial direction of the insertion portion 11, the first bending portion 24 and the second bending portion 25 are located between the position A1 of the distal end surface of the first protective tube 111a and the position A2 of the proximal end surface. And since the 1st protection tube 111a is provided in the inside of the 1st bending part 24 and the 2nd bending part 25 so that the fiber part 82 may be covered, the 1st protection tube 111a which is a comparatively hard member is In the first bending portion 24 and the second bending portion 25, the built-in fiber portion 82 is protected from buckling or contact damage.

  On the other hand, the second protection tube 111b is connected to the proximal end portion of the first protection tube 111a. As shown in FIGS. 2 and 4, the second protection tube 111b covers and protects the fiber portion 82 from the position A2 on the distal end surface to the position A3 on the proximal end surface.

  In order to connect the first protection tube 111a and the second protection tube 111b, a bundle 83 of optical fibers is covered in a portion that becomes a connection portion between the first protection tube 111a and the second protection tube 111b. As described above, a metal pipe 113 for connection is covered. As shown in FIG. 4, at the outer periphery of the connection pipe 113 at the position A2, the base end surface of the first protective tube 111a and the front end surface of the second protective tube 111b are bonded by, for example, an epoxy-based adhesive. Are connected and fixed to each other. In addition, you may make it connect the 1st protection tube 111a and the 2nd protection tube 111b by heat welding.

  When the first bending portion 24 and the second bending portion 25 are bent, the second protective tube 111b is configured such that a bundle 83 of optical fibers covered with a thin and soft silicon tube 110 is seated in the vicinity of the hard first protective tube 111a. This is to prevent the silicon tube 110 from being bent or damaged by other built-in objects.

  The length of the second protective tube 111b is long enough to absorb the amount of the silicon tube 110 that is pulled when the silicon tube 110 is pulled in the distal direction inside the second portion 111b. What is necessary is just 5 cm.

  FIG. 5 is a cross-sectional view showing a cross-sectional shape of the base end faces of the first and second protective tubes. As shown in FIG. 5A, the proximal end surface of the second protective tube 111b is formed with a tapered surface on the inner peripheral surface side of the cross-sectional shape along the insertion axis of the insertion portion 11. This tapered surface is to prevent the second protective tube 111b from damaging the silicon tube 110 when the second protective tube 111b and the silicon tube 110 move in the axial direction of the insertion portion 11. Further, the proximal end surface of the second protective tube 111b is formed with a tapered surface even on the outer peripheral surface side of the cross-sectional shape along the insertion axis of the insertion portion 11. This is because the taper surface reduces damage to other built-in objects.

  Further, as shown in FIG. 5B, the proximal end surface of the first protective tube and the distal end surface of the second protective tube 111b have cross-sectional shapes along the insertion axis of the insertion portion 11, respectively. Tapered surfaces are formed on the surface side and the outer peripheral surface side. Since the proximal end surface of the first protective tube and the distal end surface of the second protective tube 111b are connected by an adhesive, the adhesive is held in a recess formed by these tapered surfaces, and the silicone tube is formed by the adhesive. This is to prevent damage to 110 or damage to other built-in objects.

  In addition, the protection tube 111 mentioned above is comprised from two members, and is connected with the adhesive agent. Although two members are connected and connected, they may be formed by one member. For example, a part of a tube of a porous member such as tetrafluoroethylene resin can be enriched by, for example, heating or impregnating or applying rubber or the like. Therefore, by heating a part of one porous member or the like, it becomes a first protective tube by making it full (that is, it is not porous and does not have pores), and the other The portion can remain porous and serve as a second protective tube. One such member, part of which is a solid part and the other part is a porous part. That is, one member can be used as a solid part corresponding to the first protective tube 111a of the protective tube 111 and a porous part corresponding to the second protective tube 111b.

  As described above, the configuration in which the built-in object is protected by the protective member has been described by taking the fiber portion 82 of the light guide LG2 as an example of the built-in object. However, the signal line of the imaging unit IPU, which is another built-in object The part 63, the fiber part 72 of the light guide LG1, and the channel tube 91 of the nozzle can be protected by the same configuration.

  Since the light guide LG1 is thicker than the light guide LG2, the first protective tube provided in the light guide LG1 may have a lower hardness than the first protective tube 111a provided in the light guide LG2.

  As described above, even if the first bending portion and the second bending portion are bent, the built-in objects in the two bending portions are protected from buckling or the like depending on the first protective tube 111a having a relatively high hardness. Is done.

(Second Embodiment)
The second embodiment is different from the first embodiment in that a densely wound spring is used instead of the first protective tube as a built-in protection member. Furthermore, the point which used the coarsely wound spring instead of the 2nd protection tube as a built-in thing protection member differs from 1st Embodiment. Since other components are the same as those in the first embodiment, the same reference numerals are given and description thereof is omitted.

  FIG. 6 is a cross-sectional view showing a configuration of a built-in fiber part and a protective member for protecting the fiber part. The built-in protection member 121 includes a densely wound spring 121a as a first protective member and a loosely wound spring 121b as a second protective member. Each spring is formed such that a metal wire having a substantially circular cross section is wound in a spiral shape.

  The spring 121a has a stepped portion (hereinafter referred to as a stepped portion) 121c having a small inner diameter and a step at the tip. When the bundle 83 of optical fibers covered by the silicon tube 110 is inserted from the base end side of the spring 121a on the base 101 side, the stepped portion on the inner peripheral surface of the stepped portion 121c is the outer peripheral portion of the base 101. A stepped portion 121c having a small inner diameter is provided at the distal end portion of the spring 121a so as to come into contact with the circumferential convex portion provided on the spring. In FIG. 6, the stepped portion 121c is closely wound, but the stepped portion 121c may be loosely wound. The stepped portion 121c is fixed to the base 101 with an adhesive.

  A loosely wound spring 121b is connected to the base end of the spring 121a. Close winding means that the spiral strands are wound so that they are in close contact with each other, and loose winding is winding so that the spiral strands are not in contact with each other. It means that

  The densely wound spring 121a extends over a certain range of at least the first bending portion 24 and the second bending portion 25, as indicated by the dotted line in FIG. 2, similarly to the first protective tube 111a of the first embodiment. The fiber portion 82 is covered from the base 101 to the inner part at the back of the distal end portion of the flexible tube portion 23. As shown in FIGS. 2 and 4, the distal end surface of the closely wound spring 121 a is located at the substantially central portion of the base 101, and the base of the closely wound spring 121 a is located inside the distal end portion of the flexible tube portion 23. The end face is located. In the axial direction of the insertion portion 11, the first bending portion 24 and the second bending portion 25 are located between the position A1 of the distal end surface of the closely wound spring 121a and the position A2 of the proximal end surface. Since the closely wound spring 121a is provided inside the first bending portion 24 and the second bending portion 25 so as to cover the fiber portion 82, the closely wound spring 121a, which is a relatively hard member, In the first bending portion 24 and the second bending portion 25, the built-in fiber portion 82 is protected from buckling or being damaged by contact.

  The loosely wound spring 121b is provided continuously at the base end of the closely wound spring 121a. The built-in protection member 121 is formed such that a part of the base end portion of one closely wound spring member is loosely wound. As shown in FIGS. 2 and 4, the loosely wound spring 121b covers and protects the built-in object from the position A2 of the proximal end portion of the closely wound spring 121a to the predetermined position A3 of the flexible tube portion 23. To do.

  In order to connect the closely wound spring 121a and the loosely wound spring 121b separately and connect them to each other, as in the first embodiment, the connecting portion of the closely wound spring 121a and the loosely wound spring 121b. Is provided so as to cover the optical fiber bundle 83 so as to cover the optical fiber bundle 83, and the base end of the closely wound spring 121a and the loosely wound spring at the outer periphery of the connecting pipe The tip of 121b may be bonded and fixed to each other by, for example, an epoxy adhesive.

  When the first bending portion 24 and the second bending portion 25 are bent, the loosely wound spring 121b is bent in the vicinity of the hard densely wound spring 121a and the bundle 83 of the optical fibers covered with the thin and soft silicon tube 110 is buckled. This is to prevent the silicon tube 110 from being damaged. The length of the loosely wound spring 121b is, for example, 5 cm.

  Further, as shown in FIG. 7, the built-in object protection member 121 may be composed only of the closely wound spring 121a. FIG. 7: is sectional drawing which shows the structure of the other example of the protection member concerning the 2nd Embodiment of this invention. This is because only the closely wound spring 121a can protect the built-in components in the first bending portion 24 and the second bending portion 25.

  Furthermore, since the densely wound spring 121a and the sparsely wound spring 121b are both substantially circular in cross section, when they are curved in the first curved portion 24 and the second curved portion 25 and come into contact with other built-in objects, Less damage to other built-in items.

  As described above, according to the second embodiment, even if the first bending portion and the second bending portion are curved, the built-in objects in the two bending portions are relatively tightly wound by the closely wound spring 121a. Is protected from buckling and the like.

  As described above, according to the built-in object protection member described in the two embodiments, in an endoscope having two curved parts, the built-in objects in the two curved parts are protected from a compression force or the like generated during the bending. Can do.

  By the way, when the two bending portions are respectively bent, the built-in object is largely moved in the radial direction in each bending portion. Therefore, a dummy tube may be provided in the insertion portion in order to protect a weakly built-in object such as a light guide.

  FIG. 8 is a cross-sectional view for explaining an example of an internal configuration of a bending portion having a dummy tube. FIG. 8 shows a cross section of the first bending portion. As described above, in the first bending portion 130, the signal line portion 131 of the imaging unit IPU, the fiber portions 132 and 133 of the light guide, the nozzles as built-in objects. The channel tube 134 is inserted. Further, as shown in the case of FIG. 8, in the first bending portion 130, there are wires 135 for bending the first bending portion 130 in the four bending directions (up and down, left and right directions), and 2 for the treatment instrument and the like. Two channels 136 and 137 are inserted.

  Furthermore, a dummy tube 138 is inserted through a gap between each built-in object or a tube through which the built-in object passes. The dummy tube 138 is a tube body such as Teflon (registered trademark). The distal end portion of the dummy tube 138 is fixed to a hole formed in the distal end portion main body with an adhesive or the like.

  Since the dummy tube 138 is disposed so as to fill the space between the built-in objects, the dummy tube 138 functions as a radial movement restriction member that restricts the movement of the built-in objects in the radial direction. As a result, since the movement of each built-in object in the radial direction is limited, it is possible to reduce damage caused by a built-in object that is weak in strength, such as a light guide, being sandwiched between other built-in objects.

1 is a configuration diagram showing an overall configuration of an endoscope apparatus including an endoscope according to a first embodiment of the present invention. It is an external view of the front end side of the insertion part concerning the 1st Embodiment of this invention. It is sectional drawing which shows the structure of the front-end | tip part of the insertion part concerning the 1st Embodiment of this invention. It is sectional drawing which shows the structure of the protection member concerning the 1st Embodiment of this invention. It is sectional drawing which shows the cross-sectional shape of the base end surface of the 1st and 2nd protection tube concerning the 1st Embodiment of this invention. It is sectional drawing which shows the structure of the protection member concerning the 2nd Embodiment of this invention. It is sectional drawing which shows the structure of the other example of the protection member concerning the 2nd Embodiment of this invention. It is sectional drawing for demonstrating the example of the internal structure of the curved part which has a dummy tube.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Endoscope apparatus, 2 Electronic endoscope, 3 Light source apparatus, 4 Video processor, 5 Monitor, 11 Insertion part, 12 Grasp part, 12a Operation part, 21 Tip part, 23 Flexible tube, 24 1st bending part, 25 second bending portion, 62 circuit portion, 63 signal line portion, 72, 82 fiber portion, 101 base, 111, 121 protection member, 111a first protection tube, 111b second protection tube, 121a tightly wound spring, 121b Sparsely wound spring, 121c Stepped partial agent Patent attorney Susumu Ito

Claims (4)

An endoscope having an insertion portion provided with a first bending portion and a second bending portion in order from a distal end portion toward a proximal end portion,
A first hardness is provided so as to cover a built-in object inserted inside the insertion portion over a range of the first bending portion and the second bending portion in the axial direction of the insertion portion. 1 protective tube,
A second protective tube that is connected to the base end of the first protective tube, covers the built-in object, and has a second hardness lower than the first hardness. A featured endoscope.   2. The endoscope according to claim 1, wherein the second protection tube has a proximal end surface in which a cross-sectional shape along the insertion axis of the insertion portion has a tapered surface on the inner peripheral surface side. An insertion portion provided with a first bending portion and a second bending portion in order from the distal end portion toward the proximal end portion;
A closely wound spring provided so as to cover a built-in object inserted inside the insertion portion over a certain range of the first bending portion and the second bending portion in the axial direction of the insertion portion; An endoscope characterized by that. The endoscope according to claim 3, further comprising a loosely wound spring that is connected to a proximal end portion of the closely wound spring and covers the built-in object.

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