Endoscope

Abstract

To provide an endoscope that can restrain expansion of the diameter of an insertion part while expanding the inner diameter of a through passage such as a channel.SOLUTION: An endoscope including a tubular insertion part to be inserted into a body cavity, includes: a main part 73 with a circular cross section; an extension part 72 formed in a portion on an outer periphery of the main part 73 and extending in a radial direction; and a treatment tool passage 78A formed at the one portion and penetrating the insertion part in an axial direction.SELECTED DRAWING: Figure 14

Description

【Technical Field】 【0001】 The present invention relates to an endoscope having a cylindrical insertion portion to be inserted into a body cavity. 【Background Art】 【0002】 Conventionally, an endoscope in which an insertion portion to be inserted into a body cavity sequentially has a first bending portion and a second bending portion from the distal end side has been widely used. 【0003】 For example, Patent Document 1 discloses an endoscope that enables reuse of a recovered imaging unit by allowing an imaging device having an imaging unit including expensive components such as an imaging element, an imaging substrate, and an imaging lens to be taken out and recovered from the insertion portion of the endoscope. 【0004】 Further, Patent Document 2 discloses an endoscope in which a bending portion in which the curvature radius of a channel tube is curved in the same dimension regardless of the bending direction is provided in an insertion portion, thereby improving the operability of the insertion portion. 【Prior Art Documents】 【Patent Documents】 【0005】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2018-228334 【Patent Document 2】 Japanese Patent No. 6223218 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0006】 In an endoscope having a through passage penetrating the insertion portion in the axial length direction and performing suction of a liquid, in order to increase the suction amount of the liquid, it is necessary to increase the inner diameter of such a through passage. However, when the inner diameter of the through passage is enlarged, the diameter of the insertion portion becomes large, and when performing an examination using the endoscope, a burden is imposed on the subject. However, the endoscopes of Patent Documents 1 and 2 have not been devised to address such problems and cannot solve them. 【0007】 This invention has been made in view of the above circumstances, and its objective is to provide an endoscope that can increase the inner diameter of a through-passage such as a channel while suppressing the increase in the diameter of the insertion section. [Means for solving the problem] 【0008】 The endoscope according to the present invention is an endoscope having a tubular insertion portion that is inserted into a body cavity, wherein the main portion has a circular cross-section, an extension portion extending radially at one location on the outer circumference of the main portion, and a through passage formed at the one location that penetrates the insertion portion in the axial direction. 【0009】 In the present invention, the through-passage can have a wide inner diameter that includes the portion corresponding to the outer circumference of the main part (the one location), and the area near the through-passage is reinforced by the extension. Such partial reinforcement prevents the overall diameter of the endoscope from increasing. [Effects of the Invention] 【0010】 According to the present invention, it is possible to increase the inner diameter of a through-pass such as a channel while suppressing the increase in the diameter of the insertion portion. [Brief explanation of the drawing] 【0011】 [Figure 1] This is an external view of an endoscope according to Embodiment 1 of the present invention. [Figure 2] This is a diagram showing the tip surface of the tip. [Figure 3] This is a cross-sectional view taken along line III-III in Figure 2. [Figure 4] Figure 2 is a cross-sectional view taken along line IV-IV. [Figure 5] This is a schematic cross-sectional view showing the configuration of the imaging device. [Figure 6] This is an explanatory diagram illustrating the connection between the cable unit and the relay section. [Figure 7] This is a diagram showing the first relay board. [Figure 8]It is a diagram for explaining the size of the first relay substrate. [Figure 9] It is a cross-sectional view taken along line IX-IX of FIG. 4. [Figure 10] It is an explanatory diagram for explaining a method of recovering an imaging device from an endoscope. [Figure 11] It is an explanatory diagram for explaining a method of recovering an imaging device from an endoscope. [Figure 12] It is an explanatory diagram for explaining a method of recovering an imaging device from an endoscope. [Figure 13] It is an explanatory diagram for explaining a method of recovering an imaging device from an endoscope. [Figure 14] It is a diagram showing the distal end surface of the distal end portion of the endoscope according to Embodiment 2. [Figure 15] It is a cross-sectional view taken along line XV-XV of FIG. 14. [Figure 16] It is a cross-sectional view taken along line XVI-XVI of FIG. 15. [Figure 17] It is a diagram showing the distal end surface of the distal end portion of the endoscope according to Embodiment 3. [Figure 18] It is a cross-sectional view taken along line XVIII-XVIII of FIG. 17. [Figure 19] It is a diagram showing the distal end surface of the distal end portion of the endoscope according to Embodiment 4. [Figure 20] It is a cross-sectional view taken along line XX-XX of FIG. 19. 【Embodiments for Carrying Out the Invention】 【0012】 Hereinafter, the endoscope according to the embodiment of the present invention will be described in detail based on the drawings. 【0013】 (Embodiment 1) FIG. 1 is an external view of an endoscope 10 according to Embodiment 1 of the present invention. The endoscope 10 of the present embodiment is a so-called disposable endoscope. The endoscope 10 includes an insertion portion 14 that is inserted into the body cavity of a subject, an operation portion 20 that operates the insertion portion 14, and a connector portion 24 that is connected to a processor and an air / water supply device (not shown). The insertion section 14 is connected to the operating section 20 via the folding stopper section 16, and the connector section 24 is connected to the operating section 20 via the universal cord 25. 【0014】 The universal cord 25 is flexible and includes an electrical wire that transmits electrical signals from the imaging means in the insertion section 14 to the connector section 24, and a water channel through which water and air pass through which air is supplied from the connector section 24. 【0015】 The operating unit 20 includes a gripping unit 205, a button 201 for receiving instructions from the user, and a bending knob 21 for operating the bending of the active bending unit 12, which will be described later. 【0016】 The gripping portion 205 has a roughly cylindrical shape, and a channel opening 22 for inserting a treatment tool or the like is provided near the folding stopper portion 16. Inside the gripping portion 205, there is a relay portion 40 that connects the imaging unit 617 of the tip portion 13 (described later) to the processor. 【0017】 The insertion portion 14 has a small diameter cylindrical shape and is configured to be bendable. The insertion portion 14 has, in order from the tip side, a tip portion 13, an active bending portion 12, and a passive bending portion 11. 【0018】 The tip section 13 includes an imaging unit 617, described later, which includes imaging means such as a CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor), a circuit board for driving the imaging means, and an observation optical system, and a lens unit 62, described later, which consists of a series of lens sets. The tip section 13 also includes an illumination optical system for illuminating the area to be observed within the body cavity. Electrical signals from the imaging unit 617 of the tip section 13 are sent to the processor via the relay section 40 and the connector section 24. 【0019】 The active bending section 12 is capable of bending actively. That is, the active bending section 12 bends in four directions in response to the operation of the bending knob 21. On the other hand, the passive bending section 11 is passively bending. That is, the passive bending section 11 bends in one of the four directions upon contact with an object. The active bending section 12 and the passive bending section 11 are made of, for example, a multi-lumen tube and are integrally formed. 【0020】 Figure 2 shows the tip surface 131 of the tip portion 13, Figure 3 is a cross-sectional view taken along line III-III in Figure 2, and Figure 4 is a cross-sectional view taken along line IV-IV in Figure 2. The tip portion 13 has a cylindrical shape and a larger diameter than the active bending portion 12. A flange portion 70 is provided along the periphery of the end face of the tip portion 13 on the side facing the active bending portion 12. The tip portion of the active bending portion 12 is fitted into the flange portion 70. 【0021】 The endoscope 10 has an imaging device 15 housed within the insertion section 14 and the folding section 16. The imaging device 15 includes a lens unit 62 and an imaging unit 617, the imaging unit 617 being connected to the relay section 40 via a cable unit 50. 【0022】 Figure 5 is a schematic cross-sectional view showing the configuration of the imaging device 15. The imaging device 15 includes a housing tube 60 that houses a lens unit 62 and an imaging unit 617. The housing tube 60 is a rectangular tube, with a circular opening 61 at one end having a circular inner surface, and a rectangular opening 68 at the other end having a square inner surface. The lens unit 62 is inserted into the circular opening 61, and the imaging unit 617 is inserted into the rectangular opening 68. A light-shielding mask 614 is provided between the lens unit 62 and the imaging unit 617. 【0023】 The lens unit 62 has an observation window 132 and a plurality of imaging lenses 621. The observation window 132 and the plurality of imaging lenses 621 are arranged on the same axis. The observation window 132 and the plurality of imaging lenses 621 are fixed by the lens frame 622 with their outer surfaces covered when the focus has been adjusted. 【0024】 The imaging unit 617 includes a filter 623, an image sensor 611, and an imaging substrate 612. The filter 623 removes unwanted light, such as infrared light, from the light incident on the image sensor 611. Light incident from the lens unit 62 is imaged onto the image sensor 611, and the image sensor 611 converts the optical image into an electrical signal. The imaging substrate 612 incorporates a driver circuit that controls the image sensor 611. A cable unit 50 is connected to the imaging substrate 612 from the other end of the housing cylinder 60. 【0025】 The cable unit 50 comprises multiple cable strands 511 bundled together by a cable tube 51. One end of the cable unit 50 is connected to the imaging substrate 612. The connection between one end of the cable unit 50 and the imaging substrate 612 is potted with an insulating resin 54. 【0026】 The filter 623, image sensor 611, imaging substrate 612, and one end of the cable unit 50 are held together by an insulating tube 535 in their assembled state. The insulating tube 535 is a heat-shrinkable tube that shrinks with heat to fix each component in place and maintain the assembled state. 【0027】 The cable unit 50 extends outward from the other end of the housing cylinder 60. The other end of the cable unit 50 is connected to the relay section 40 (Figure 1). Figure 6 is an explanatory diagram illustrating the connection between the cable unit 50 and the relay unit 40. The relay unit 40 comprises a first relay board 55 to which the other end of the cable unit 50 is connected, and a second relay board 253 to which a plurality of cable strands 252 are connected. The first relay board 55 is equipped with a connection connector 552, and each cable strand 252 is connected to the processor via a universal cord 25 and a connector section 24. The first relay board 55 and the second relay board 253 are arranged opposite each other, with the connection connector 552 interposed between them, and the first relay board 55 and the second relay board 253 are connected via the connection connector 552. 【0028】 Figure 7 shows the first relay board 55. In Figure 7, for ease of explanation, the connection connector 552 is shown with a dotted line. 【0029】 The first relay substrate 55 has a substantially rectangular shape, and one end corner is rounded off. A circular through hole 554 is formed at the aforementioned end of the first relay substrate 55. Furthermore, a rectangular land portion 553 is formed on the first relay board 55, extending from the other end to the middle portion in the longitudinal direction. A pair of land portions 553 are formed in the width direction of the first relay board 55, and multiple pairs of land portions 553 are arranged side by side in the longitudinal direction of the first relay board 55. 【0030】 Each land portion 553 is connected to a connection connector 552 through the inside of the first relay board 55. The other end of the cable strands 511 of the cable unit 50 is soldered to each land portion 553, for example. The connection between the cable strands 511 and the land portion 553 is potted with an insulating resin 557. 【0031】 The second relay board 253, like the first relay board 55, has land portions 555 and through holes 556. Each land portion 555 is connected to the connection connector 552 through the inside of the second relay board 253. Corresponding cable strands 252 are soldered to each land portion 555. Since the first relay board 55 and the second relay board 253 have the same shape, a detailed explanation of the second relay board 253 will be omitted. 【0032】 Furthermore, the connection connector 552 is also connected to the land portions 555 through the inside of the second relay board 253. In other words, each land portion 553 of the first relay board 55 is connected one-to-one with each land portion 555 of the second relay board 253 via the connection connector 552. 【0033】 The first relay board 55 and the second relay board 253 are arranged opposite each other such that the surfaces on which the land portions 553 and 555 are formed are facing opposite directions. In this arrangement, the through-hole 554 of the first relay board 55 and the through-hole 556 of the second relay board 253 are aligned in the opposing direction of the first relay board 55 and the second relay board 253. The first relay board 55 and the second relay board 253 are fixed in place by inserting screws 259 into the through-hole 554 of the first relay board 55 and the through-hole 556 of the second relay board 253 and screwing them into screw holes formed in the frame 258 mounted inside the operating section 20. 【0034】 A unit hole 71 is formed in the tip portion 13, extending through it in the axial direction. The unit hole 71 is formed in the center of half of the circular tip surface 131. The unit hole 71 has a rectangular cross-section, and the imaging device 15 is inserted into it. The observation window 132 is exposed from the tip surface 131. In the housing cylinder 60, two opposing outer surfaces of the end of the circular hole 61 have crab-eye holes 619 formed thereon. Also, at the end of the rectangular hole 68, one of the two outer surfaces has a recess 682 formed thereon (see Figure 4). 【0035】 The housing cylinder 60 is positioned such that the opposing directions of the two outer surfaces on which the crab-eye holes 619 are formed coincide with the radial direction passing through the axis of the observation window 132. In this configuration, the surface on which the recess 682 and the crab-eye holes 619 are formed is located closer to the edge than the other three surfaces. 【0036】 A cable hole 42 is formed in the active bending section 12 at a position corresponding to the unit hole 71. The cable hole 42 is circular in cross-section and penetrates the active bending section 12 in the axial direction. The cable hole 42 of the active bending section 12 communicates with the unit hole 71 of the tip section 13, and the unit hole 71 and the cable hole 42 are located on the same axis. A cable unit 50 is inserted into the cable hole 42. 【0037】 The passive bending portion 11 and the folding portion 16 have through holes with the same diameter as the cable hole 42 of the active bending portion 12. (Not shown) are formed in each, and these through holes communicate with the cable hole 42. The cable unit 50 extends to the relay section 40 of the operating section 20 through the through holes of the passive bending section 11 and the bending section 16. 【0038】 Figure 8 illustrates the dimensions of the first relay board 55. For convenience, the cable holes 42 are shown with dashed lines, and the figure shows the board with the second relay board 253 removed. The diameter of the cable tube 51 is smaller than the diameter of the cable hole 42, and the width dimension of the first relay board 55 is smaller than the diameter of the cable tube 51. Therefore, the first relay board 55 is movable within the cable hole 42 of the active bending section 12, and within the through holes of the passive bending section 11 and the folding section 16. 【0039】 On the tip surface 131 of the tip portion 13, illumination windows 133 are provided, flanking an observation window 132, in directions perpendicular to the opposing directions of the two outer surfaces of the housing cylinder 60. Specifically, illumination holes 76 are formed on both sides of the unit hole 71 in the tip portion 13, penetrating the tip portion 13 in the axial direction. The illumination holes 76 have a circular cross-section, with one end opening to the tip surface 131, and the illumination window 133 is positioned at this end. 【0040】 Each illumination hole 76 has an illumination element 136 inserted into it, and the illumination window 133 widens the irradiation angle of the illumination light emitted from the illumination element 136. Each illumination element 136 is connected to an illumination cable 761 from the other end of the illumination hole 76, and the illumination cable 761 supplies power to the illumination element 136. 【0041】 In the actively bending section 12, a lighting cable hole 46 is formed at a position corresponding to the lighting hole 76. The lighting cable hole 46 has a circular cross-section and a smaller diameter than the cable hole 42, and penetrates the actively bending section 12 in the axial direction. The lighting cable hole 46 of the actively bending section 12 communicates with the lighting hole 76 of the tip section 13, and the lighting hole 76 and the lighting cable hole 46 are located on the same axis. A lighting cable 761 is inserted into the lighting cable hole 46. 【0042】 The passive bending section 11 has through holes (not shown) with the same diameter as the lighting cable hole 46 of the active bending section 12, and these through holes communicate with the lighting cable hole 46. The lighting cable 761 extends through the through holes in the passive bending section 11 and the bending section 16, through the operating section 20, and to the connector section 24. 【0043】 A roughly semicircular recess 75 is formed in approximately half of the tip surface 131 of the tip portion 13. Two illumination windows 133 and an observation window 132 are located at the bottom of the recess 75. Specifically, two illumination holes 76 and a unit hole 71 are open at the bottom of the recess 75. 【0044】 The recess 75 is covered by a semicircular window plate 145 that conforms to the shape of the recess 75. The surface of the window plate 145 is flush with the tip surface 131. In addition, both ends of the linearly extending edge of the window plate 145 are rounded off, creating a gap between it and the side wall of the recess 75. 【0045】 In the remaining half of the tip surface 131, near one of the two illumination windows 133, there is an air nozzle 143 and a water nozzle 144 used for cleaning the window plate 145 during endoscopic examination, and a jet outlet 141 used for washing away residue, mucus, blood, etc. from the area under observation. 【0046】 Water or air supplied from the air supply device via the universal cord 25 and water supply holes (not shown) or air supply holes (not shown) passing through the active bending section 12, passive bending section 11, and folding section 16 is discharged from the water supply nozzle 144 or air supply nozzle 143 toward the observation window 132 in response to the operation of the operation unit 20. 【0047】 The jet outlet 141 is narrowed in diameter near the tip surface 131, and water supplied from the air supply and water supply device is forcefully discharged from the jet outlet 141 via the universal cord 25 and water supply holes (not shown) that penetrate the active bending section 12, the passive bending section 11, and the bend-stop section 16. 【0048】 The insertion portion 14 has a curved wire hole formed therein for a curved wire 17 for bending the tip portion 13, which penetrates the insertion portion 14 in the axial direction. The curved wire hole consists of a curved wire hole 47 formed in the active bending portion 12 and curved wire holes formed in the passive bending portion 11 and the folding portion 16, respectively. The curved wire hole 47 of the active bending portion 12 and the curved wire holes of the passive bending portion 11 and the folding portion 16 have the same shape and are in communication with each other. For convenience, only the curved wire hole 47 will be described below. 【0049】 The curved wire holes 47 are circular in cross-section, and four curved wire holes 47 are formed near the outer circumferential surface of the active curved portion 12. The curved wire holes 47 are formed at equal intervals in the circumferential direction. One end of each curved wire hole 47 opens at the end face of the tip portion 13 of the active curved portion 12. 【0050】 At the tip portion 13, a recess 77 is formed on the end face on the active bending portion 12 side, at a position corresponding to one end of the bending wire hole 47. That is, four recesses 77 are formed on the end face of the tip portion 13 at equal intervals in the circumferential direction. Each recess 77 is circular in cross-section and has a larger diameter than the bending wire hole 47. Each recess 77 is formed coaxially with the corresponding bending wire hole 47. 【0051】 A curved wire 17 is inserted into each curved wire hole 47. One end of the curved wire 17 protrudes into the corresponding recess 77 through the curved wire hole 47. The other end of the curved wire 17 is fixed into the recess 77 by brazing, crimping, or the like. The other end of the curved wire 17 is connected to the curved knob 21 of the operating unit 20 via the curved wire hole. When the user operates the curved knob 21, the curved wire 17 curves the active curved section 12. 【0052】 Furthermore, as shown in Figure 4, a communication hole 712 is formed on the outer circumferential surface of the tip portion 13, in the radial direction, at a position corresponding to the recess 682 of the housing cylinder 60, and communicating with the unit hole 71. The communication hole 712 has a circular cross-section, and screw threads are formed on its inner circumferential surface. A fixing screw 69 is screwed into the communication hole 712. The position of the housing cylinder 60 within the unit hole 71 is fixed by the fixing screw 69 pressing against the housing cylinder 60. 【0053】 Figure 9 is a cross-sectional view taken along the line IX-IX in Figure 4. The insertion section 14 has a tool passage that penetrates the insertion section 14 in the axial direction, through which a treatment tool (see dashed line in Figure 2) inserted from the channel inlet 22 passes. The tool passage includes a tool passage 78 formed at the tip section 13, a tool passage 48 formed at the active bending section 12, and a tool passage (not shown) formed at the passive bending section 11 (see Figure 4). The tool passages 78, 48, and 11 have a roughly circular cross-section and the same diameter. The tool passages 78, 48, and 11 have a diameter that is, for example, 0.1 to 0.5 mm larger than the diameter of the treatment tool. One end of the treatment tool passage 78 (hereinafter referred to as the channel outlet 142) is widened in diameter and opens near the other of the two illumination windows 133 at the remaining half of the tip surface 131. The other end of the treatment tool passage 78 is in communication with one end of the treatment tool passage 48 via the channel pipe 781 (see Figure 4). 【0054】 Specifically, a channel pipe 781 is interposed between the tip portion 13 and the active bending portion 12. One end of the channel pipe 781 is fitted into the treatment tool passage 78, and the other end of the channel pipe 781 is fitted into the treatment tool passage 48. The channel pipe 781 is arranged on the same axis as the treatment tool passages 78 and 48. The other end of the treatment tool passage 48 is in communication with the treatment tool passage of the passive bending portion 11. 【0055】 Furthermore, the insertion section 14 has two fluid passages 79 that penetrate the insertion section 14 in the axial direction (see Figure 1). Each fluid passage 79 includes through holes of the same diameter that penetrate the active bending section 12, the passive bending section 11, and the folding section 16, and these through holes are in communication with each other. Moreover, each fluid passage 79 has a substantially circular cross-section and a smaller diameter than the treatment tool passage 78. One end of each fluid passage 79 (hereinafter referred to as the fluid passage opening 791) opens near the other of the two illumination windows 133 in the remaining half of the tip surface 131. Fluid such as perfusion fluid is drawn in through the fluid passage opening 791 and flows through the fluid passage 79 to the operating section 20 side. 【0056】 The two fluid passages 79 are formed so as to face each other in the radial direction of the treatment tool passage 78, the treatment tool passage 48, and the treatment tool passage of the passive bending section 11. The positional relationship with the fluid passage 79 is the same for all of the treatment tool passages 78, 48, and the treatment tool passage of the passive bending section 11, and for the sake of explanation, only the treatment tool passage 78 will be described below. 【0057】 The instrument passage 78 and the two fluid passages 79 are formed so that they are partially continuous in cross-sectional view. That is, as shown in Figures 2 and 9, the circle C1 defined by the cross-section of the instrument passage 78 partially overlaps with the circle C2 defined by the cross-sections of each fluid passage 79, and the instrument passage 78 and the fluid passages 79 are integrated as a whole. In other words, the treatment tool passage 78 and the two fluid passages 79 are integrated, and in cross-sectional view, a single hole is formed consisting of two superior arc-shaped portions related to the fluid passage 79 and two inferior arc-shaped portions related to the treatment tool passage 78. The superior arc-shaped portions and the inferior arc-shaped portions face each other. 【0058】 The distance from the axis of the tip portion 13 (insertion portion 14) to each fluid passage 79, that is, the distance L2 from the axis of the tip portion 13 to the center of circle C2 relating to the fluid passage 79, is greater than or equal to the distance from the axis of the tip portion 13 (insertion portion 14) to the treatment tool passage 78, that is, the distance L1 from the axis of the tip portion 13 to the center of circle C1 relating to the treatment tool passage 78. In other words, the treatment tool passage 78 and the fluid passage 79 are formed at equal positions from the outer circumferential surface of the tip portion 13, or the fluid passage 79 is formed at an outer position closer to the outer circumferential surface of the insertion portion 14 than the treatment tool passage 78. 【0059】 The endoscope 10 of Embodiment 1, having the above configuration, allows for the recovery and reuse of the expensive imaging device 15 after a single use. 【0060】 Figures 10 to 13 are explanatory diagrams illustrating the method for retrieving the imaging device 15 from the endoscope 10. The retrieval of the imaging device 15 will be explained in detail below. 【0061】 First, the operating unit 20 is disassembled and the first relay board 55 is removed from the relay unit 40 (see Figures 1 and 6). Next, the window plate 145 is removed from the tip unit 13 by inserting a jig into the gap between the window plate 145 and the side wall of the recess 75 and prying it open (see Figure 2). 【0062】 Next, the fixing screw 69 is removed from the communication hole 712. As a result, the recess 682 is exposed through the communication hole 712, as shown in Figure 10. As shown in Figure 11, an extrusion jig 81 with a rod-shaped tip is inserted into the recess 682 through the communication hole 712. The recess 682 is pushed out towards the tip side of the tip portion 13 (in the direction of the arrow in Figure 11) using the extrusion jig 81. As a result, as shown in Figure 12, the tip of the imaging device 15 protrudes from the tip surface 131 of the tip portion 13, and the crab-eye hole 619 is exposed. 【0063】 After this, as shown in Figure 13, the imaging device 15 can be removed from the endoscope 10 by inserting the crab-eye jig 82 into the two crab-eye holes 619 and pulling the imaging device 15. As described above, since the cable tube 51 and the first relay board 55 are smaller than the diameter of the cable hole 42, the cable tube 51 and the first relay board 55 can be removed from the insertion section 14 through the cable hole 42 and the unit hole 71. By performing the above steps, the imaging device 15 can be removed from the endoscope 10. 【0064】 Furthermore, having the above configuration, the endoscope 10 of Embodiment 1 can achieve both improved accuracy in controlling the position of the treatment instrument and securing a gap for liquid aspiration. As described above, the instrument passages 78 and 48 have a diameter slightly larger than the diameter of the instrument. Therefore, the instrument is constrained by the instrument passages 78 and 48, and the movement of the instrument follows the movement of the instrument passages 78 and 48. Thus, by operating the bending knob 21 to bend the active bending section 12, the user can precisely control the orientation of the instrument. 【0065】 Furthermore, since the holes in the fluid passage 79 are always secured separately from the treatment tool passage 78, a stable supply of fluids such as perfusion fluid can be drawn in. Furthermore, even in procedures performed while irrigating with fluids such as saline solution, such as cholangioscopy and cystoscopy, sufficient irrigation can be achieved through the fluid passage 79 while inserting the instrument through the instrument passage 78. Furthermore, since the treatment tool passage 78 and the fluid passage 79 are integrated to form a single opening, the configuration can be made more compact compared to when the treatment tool passage 78 and the fluid passage 79 are provided separately. 【0066】 Furthermore, as described above, in the endoscope 10 of Embodiment 1, the fluid passage 79 is formed at an outer position closer to the outer surface of the insertion section 14 than the treatment instrument passage 78. Therefore, when performing an endoscopic examination using the endoscope 10, the fluid from the area to be examined can be drawn in from a lower position. Consequently, the fluid flows more easily along gravity, and the fluid can be drawn in more cleanly. 【0067】 In the above explanation, the case in which the endoscope 10 has two fluid passages 79 was described as an example, but it is not limited to this, and a configuration with one fluid passage 79 is also possible. 【0068】 (Embodiment 2) Figure 14 shows the tip surface 131 of the tip portion 13 in the endoscope 10 according to Embodiment 2, Figure 15 is a cross-sectional view taken along the line XV-XV in Figure 14, and Figure 16 is a cross-sectional view taken along the line XVI-XVI in Figure 15. 【0069】 In the endoscope 10 of Embodiment 2, the insertion portion 14 includes a main portion 73 with a circular cross-section and an extension portion 72 extending radially from one point P on the outer circumference of the main portion 73. The extension portion 72 is formed along the entire length of the insertion portion 14. That is, in the insertion portion 14, the outer surface of the main portion 73 has a predominantly arc shape in cross-section, and the outer surface of the extension portion 72 has a less arc shape in cross-section. 【0070】 Similar to Embodiment 1, a roughly semicircular recess 75 is formed in approximately half of the tip surface 131 of the tip portion 13. A unit hole 71 is formed in the center of the recess 75, penetrating the tip portion 13 in the axial direction. The unit hole 71 is rectangular in cross-section, and the imaging device 15 is inserted into it. The observation window 132 of the imaging device 15 is exposed from the tip surface 131. In addition, two illumination windows 133 and an observation window 132 are arranged on both sides of the imaging device 15 at the bottom of the recess 75. 【0071】 Furthermore, in the remaining half of the tip surface 131, near one of the two illumination windows 133, there is an air supply nozzle 143 and a water supply nozzle 144 used for cleaning the window plate 145 during endoscopic examination, and a jet outlet 141 used for washing away residue, mucus, blood, etc. from the area under observation. Detailed explanation of the same parts as in Embodiment 1 is omitted. 【0072】 In the endoscope 10 of Embodiment 2, a treatment instrument passage (through passage) is formed at one location P through which a treatment instrument inserted from the channel inlet 22 (see Figure 1) passes. The treatment instrument passage penetrates the insertion section 14 in the axial direction. The treatment instrument passage includes a treatment instrument passage 78A formed at the tip section 13, a treatment instrument passage 48A formed at the active bending section 12, and a treatment instrument passage (not shown) formed at the passive bending section 11. The treatment instrument passages 78A, 48A, and the passive bending section 11 are circular in cross-section and have the same diameter. 【0073】 One end of the treatment tool passage 78A (hereinafter referred to as the channel outlet 142A) is widened in diameter and opens near the other of the two illumination windows 133 at the remaining half of the tip surface 131. The other end of the treatment tool passage 78A is in communication with one end of the treatment tool passage 48A via the channel pipe 781. 【0074】 Specifically, a channel pipe 781 is interposed between the tip portion 13 and the active bending portion 12, and the channel pipe 781 has a circular cross-section. One end of the channel pipe 781 is fitted into the treatment tool passage 78A, and the other end of the channel pipe 781 is fitted into the treatment tool passage 48A. The channel pipe 781 is arranged on the same axis as the treatment tool passages 78A and 48A. The other end of the treatment tool passage 48A is in communication with the treatment tool passage of the passive bending portion 11. Since the treatment tool path 78A, the treatment tool path 48A, and the treatment tool path of the passive bending section 11 have the same shape, only the treatment tool path 78A will be described below. 【0075】 As described above, the treatment tool path 78A is formed at one location P. The treatment tool path 78A is formed at one location P, including a position that is separated from the center of the main part 73 by the radius of the main part 73, and the center of the treatment tool path 78A is located on the line connecting the one location P and the center of the main part 73. 【0076】 In other words, the extension portion 72 is formed such that a position at a distance from the center of the main portion 73 by the radius of the main portion 73, or in other words, a position on the extension of the outer circumference of the main portion 73 (the dashed line in Figure 14), is included in the treatment tool passage 78A (channel outlet 142A) (see Figure 14). Figure 14 shows an example where the edge of the channel outlet 142A is located on the extension of the outer circumference of the main portion 73, but it is not limited to this, and the treatment tool passage 78A may be provided such that the extension of the outer circumference of the main portion 73 is located inside the edge of the channel outlet 142A. 【0077】 The instrument inserted through the channel inlet 22 (see Figure 1) exits the channel outlet 142A through the instrument passages of the passive bending section 11, instrument passage 48A, and instrument passage 78A, allowing for diagnosis, treatment, etc., to be performed inside the body. During this process, a gap exists between the instrument and the instrument passages 78A, 48A, and the instrument passage of the passive bending section 11. Fluids such as body fluids from within the body cavity can be drawn in through this gap. 【0078】 In particular, in the endoscope 10 of Embodiment 2, as described above, the treatment instrument passage 78A, treatment instrument passage 48A, and treatment instrument passage of the passive bending section 11 are formed over a wide area that includes a position that is separated from the center of the main section 73 by the radius of the main section 73. Therefore, a wide gap can be secured between the treatment instrument and the treatment instrument passage 78A, treatment instrument passage 48A, and treatment instrument passage of the passive bending section 11, allowing for stable liquid suction. Therefore, even in procedures such as cholangioscopy and cystoscopy, which are performed while irrigating with a fluid such as physiological saline, sufficient irrigation can be achieved. 【0079】 Furthermore, in the endoscope 10 of Embodiment 2, as described above, the treatment instrument passage is formed over a wide area near the edge of the insertion section 14. Therefore, an extension 72 is provided to reinforce the strength associated with this, and the necessary thickness is secured between the treatment instrument passage 78A, treatment instrument passage 48A, and the passive bending section 11 and the outer surface of the insertion section 14. 【0080】 In other words, instead of increasing the diameter of the insertion section 14 itself, the extension section 72 is provided only in the parts of the treatment instrument passage 78A, treatment instrument passage 48A, and the passive bending section 11 where the treatment instrument passage exists, thereby minimizing the increase in the thickness of the insertion section 14. This minimizes the burden on the patient undergoing the endoscopic examination. 【0081】 Other components of the endoscope 10 in Embodiment 2 are the same as those of the endoscope 10 in Embodiment 1, and parts similar to those in Embodiment 1 are denoted by the same reference numerals and detailed descriptions are omitted. 【0082】 (Embodiment 3) Figure 17 shows the tip surface 131 of the tip portion 13 in the endoscope 10 according to Embodiment 3, and Figure 18 is a cross-sectional view taken along line XVIII-XVIII in Figure 17. 【0083】 The insertion portion 14 includes a main portion 73 with a circular cross-section and an extension portion 72 extending radially from one point P on the outer circumference of the main portion 73. The extension portion 72 is formed along the entire length of the insertion portion 14. That is, in the insertion portion 14, the outer surface of the main portion 73 has a superior arc shape in cross-section, and the outer surface of the extension portion 72 has a inferior arc shape in cross-section. 【0084】 Similar to Embodiment 1, a roughly semicircular recess 75 is formed in approximately half of the tip surface 131 of the tip portion 13, and a unit hole 71 is formed in the center of the recess 75. The imaging device 15 is inserted into the unit hole 71, and the observation window 132 of the imaging device 15 is exposed from the tip surface 131. At the bottom of the recess 75, two illumination windows 133 and an observation window 132 are arranged on both sides of the imaging device 15. 【0085】 Furthermore, in the remaining half of the tip surface 131, near one of the two illumination windows 133, an air supply nozzle 143, a water supply nozzle 144, and a jet outlet 141 are provided. Detailed explanation of the same parts as in Embodiment 1 is omitted. 【0086】 The insertion section 14 has a tool passage that penetrates the insertion section 14 in the axial direction, through which a treatment tool (see dashed line in Figure 17) inserted from the channel inlet 22 (see Figure 1) passes. The tool passage includes a tool passage 78B formed in the tip section 13, a tool passage 48B formed in the active bending section 12, and a tool passage (not shown) formed in the passive bending section 11. The tool passages 78B, 48B, and the passive bending section 11 are approximately circular in cross-section and have the same diameter. The tool passages 78B, 48B, and the passive bending section 11 have a diameter that is, for example, 0.1 to 0.5 mm larger than the diameter of the treatment tool. 【0087】 One end of the treatment tool passage 78B (hereinafter referred to as the channel outlet 142B) is widened and opens near the other of the two illumination windows 133. The other end of the treatment tool passage 78B is connected to one end of the treatment tool passage 48B via the channel pipe 781A. The other end of the treatment tool passage 48B is connected to the treatment tool passage of the passive bending section 11. 【0088】 Furthermore, the insertion portion 14 has a fluid passage (through passage) that penetrates the insertion portion 14 in the axial direction. The fluid passage includes a fluid passage 79A formed in the tip portion 13, a fluid passage 49 formed in the active bending portion 12, and a fluid passage (not shown) formed in the passive bending portion 11. The fluid passages 79A, 49, and the passive bending portion 11 are approximately circular in cross-section and have the same diameter. The fluid passages 79A, 49, and the passive bending portion 11 have a larger diameter than the diameter of the treatment tool passage. 【0089】 One end of the fluid passage 79A (hereinafter referred to as the fluid passage opening 791A) is widened and opens near the other of the two illumination windows 133. The other end of the fluid passage 79A is connected to one end of the fluid passage 49 via a channel pipe 781A. The other end of the fluid passage 49 is connected to the fluid passage of the passive bending section 11. Fluid such as perfusion liquid is drawn in through the fluid passage opening 791A and flows through the fluid passage 79A and the fluid passage 49 towards the operating section 20. 【0090】 As described above, a channel pipe 781A is interposed between the tip portion 13 and the actively bending portion 12, and the channel pipe 781A has a roughly "8" shape in cross-section. One end of the channel pipe 781A is fitted into the treatment tool passage 78B and the fluid passage 79A, and the other end of the channel pipe 781A is fitted into the treatment tool passage 48B and the fluid passage 49. 【0091】 The treatment tool passage and the fluid passage are formed to be adjacent to each other. That is, the treatment tool passage 78B, the treatment tool passage 48B, and the treatment tool passage of the passive bending section 11 are adjacent to the fluid passage 79A, the fluid passage 49, and the fluid passage of the passive bending section 11, respectively. The positional relationship between the treatment tool passage and the fluid passage is the same throughout the entire length of the insertion section 14, and for the sake of explanation, only the positional relationship between the treatment tool passage 78B and the fluid passage 79A will be described below. 【0092】 The treatment tool passage 78B and the fluid passage 79A are formed to be partially continuous in cross-sectional view. As shown in Figure 17, the circle defined by the channel outlet 142B of the treatment tool passage 78B and the circle defined by the fluid passage opening 791A of the fluid passage 79A partially overlap. Overall, the channel outlet 142B and the fluid passage opening 791A are integrated, forming roughly the shape of the number "8". In other words, the treatment tool passage 78B and the fluid passage 79A are integrated, and in cross-sectional view, a single hole is formed consisting of an arc-shaped portion related to the fluid passage 79A and an arc-shaped portion related to the treatment tool passage 78B. 【0093】 The distance from the axis of the main section 73 to the through passage is longer than the distance from the axis of the main section 73 to the treatment tool passage. In other words, the distance from the axis of the main section 73 to the axis of the fluid passage 79A is longer than the distance from the axis of the main section 73 to the axis of the treatment tool passage 78B. In other words, the fluid passage 79A is formed closer to the outer surface of the insertion section 14 than the treatment tool passage 78B. 【0094】 As described above, the fluid passage 79A is formed at one location P. The fluid passage 79A is formed at one location P, including a position that is separated from the center of the main portion 73 by the radius of the main portion 73, and the center of the fluid passage 79A is located on the line connecting the one location P and the center of the main portion 73. 【0095】 In other words, the extension portion 72 is formed such that a position at a distance from the center of the main portion 73 by the radius of the main portion 73, or in other words, a position on the extension of the outer circumference of the main portion 73 (the dashed line in Figure 17), is included in the fluid passage 79A (fluid passage opening 791A) (see Figure 17). On the other hand, the center of the treatment tool passage 78B is located on a line connecting point P and the center of the main section 73, and is located closer to the center of the main section 73 than the center of the fluid passage 79A. 【0096】 A treatment instrument inserted through the channel inlet 22 (see Figure 1) exits the channel outlet 142B through the treatment instrument passage, treatment instrument passage 48B, and treatment instrument passage 78B of the passive bending section 11, and is used for diagnosis, treatment, etc., inside the body. In addition, a fluid such as perfusion fluid is drawn in through the fluid passage inlet 791A and flows through the fluid passage 79A, fluid passage 49, and the fluid passage of the passive bending section 11. 【0097】 As described above, in the endoscope 10 of Embodiment 3, the fluid passages of the fluid passage 79A, the fluid passage 49, and the passive bending section 11 are formed over a wide area that includes a position that is separated from the center of the main section 73 by the radius of the main section 73. Therefore, the fluid passages of the fluid passage 79A, the fluid passage 49, and the passive bending section 11 can be secured over a wide area, and liquid suction can always be performed stably. Therefore, even in procedures such as cholangioscopy and cystoscopy, which are performed while irrigating with a fluid such as physiological saline, irrigation can be stably carried out through the fluid channel while inserting the instrument through the instrument channel. 【0098】 Furthermore, in the endoscope 10 of Embodiment 3, as described above, the fluid passage is formed over a wide area near the edge of the insertion section 14. Therefore, an extension section 72 is provided to reinforce the strength associated with this, and the necessary thickness is secured between the fluid passages of the fluid passage 79A, the fluid passage 49, and the passive bending section 11 and the outer surface of the insertion section 14. In other words, instead of increasing the diameter of the insertion section 14 itself, the extension section 72 is provided only in the parts where the fluid passages 79A, 49, and the passive bending section 11 exist, thereby minimizing the increase in the thickness of the insertion section 14. This minimizes the burden on the patient undergoing the endoscopic examination. 【0099】 Furthermore, in the endoscope 10 of Embodiment 3, as described above, the instrument passage 78B, instrument passage 48B, and the instrument passage of the passive bending section 11 (hereinafter simply referred to as the instrument passage) have a diameter slightly larger than the diameter of the instrument. Therefore, the instrument is constrained by the instrument passage, and the movement of the instrument follows the movement of the instrument passage. Thus, by bending the active bending section 12 by operating the bending knob 21 (see Figure 1), the user can control the orientation of the instrument with high precision. 【0100】 Furthermore, in the endoscope 10 of Embodiment 3, as described above, the fluid passage is formed closer to the outer surface of the insertion section 14 than the treatment instrument passage. Therefore, when performing an endoscopic examination using the endoscope 10, the fluid from the area to be examined can be drawn in from a lower position. Consequently, the fluid flows more easily along gravity, and the fluid can be drawn in more cleanly. 【0101】 Other components of the endoscope 10 in Embodiment 3 are the same as those of the endoscope 10 in Embodiment 1, and parts similar to those in Embodiment 1 are denoted by the same reference numerals and detailed descriptions are omitted. 【0102】 (Embodiment 4) Figure 19 shows the tip surface 131 of the tip portion 13 in the endoscope 10 according to Embodiment 4, and Figure 20 is a cross-sectional view taken along the line XX-XX in Figure 19. In the fourth embodiment of the endoscope 10, the insertion portion 14 has an extension portion 72 that extends radially outward from the main portion 73, similar to embodiments 2 and 3, along its entire length. 【0103】 Similar to Embodiment 1, a roughly semicircular recess 75 is formed in approximately half of the tip surface 131 of the tip portion 13, and a unit hole 71 is formed in the center of the recess 75. The imaging device 15 is inserted into the unit hole 71, and the observation window 132 of the imaging device 15 is exposed from the tip surface 131. At the bottom of the recess 75, two illumination windows 133 and an observation window 132 are arranged on both sides of the imaging device 15. 【0104】 Furthermore, in the remaining half of the tip surface 131, near one of the two illumination windows 133, an air supply nozzle 143, a water supply nozzle 144, and a jet outlet 141 are provided. Detailed explanation of the same parts as in Embodiment 1 is omitted. 【0105】 The insertion section 14 has a tool passage that penetrates the insertion section 14 in the axial direction, through which a treatment tool (see dashed line in Figure 19) inserted from the channel inlet 22 (see Figure 1) passes. The tool passage includes a tool passage 78C formed in the tip section 13, a tool passage 48C formed in the active bending section 12, and a tool passage (not shown) formed in the passive bending section 11. The tool passages 78C, 48C, and the passive bending section 11 are circular in cross-section and have the same diameter. The tool passages 78C, 48C, and the passive bending section 11 have a diameter that is, for example, 0.1 to 0.5 mm larger than the diameter of the treatment tool. One end of the treatment tool passage 78C (hereinafter referred to as the channel outlet 142C) is widened and opens near the other of the two illumination windows 133. The other end of the treatment tool passage 78C is connected to one end of the treatment tool passage 48C via the channel pipe 781B. The other end of the treatment tool passage 48C is connected to the treatment tool passage of the passive bending section 11. 【0106】 Furthermore, the insertion portion 14 has a fluid passage (through passage) that penetrates the insertion portion 14 in the axial direction. The fluid passage includes a fluid passage 79B formed in the tip portion 13, a fluid passage 49A formed in the active bending portion 12, and a fluid passage (not shown) formed in the passive bending portion 11. The fluid passages 79B, 49A, and the passive bending portion 11 are circular in cross-section and have the same diameter. The fluid passages 79B, 49A, and the passive bending portion 11 have a diameter larger than the diameter of the treatment tool passage. One end of the fluid channel 79B (hereinafter referred to as the fluid channel opening 791B) is widened and opens near the other of the two illumination windows 133. The other end of the fluid channel 79B is connected to one end of the fluid channel 49A via the fluid channel pipe 782. The other end of the fluid channel 49A is connected to the fluid channel of the passive bending section 11. Fluid such as perfusion liquid is drawn in through the fluid channel opening 791B and flows through the fluid channels 79B and 49A towards the operating section 20. 【0107】 As described above, a channel pipe 781B and a fluid passage pipe 782 are interposed between the tip portion 13 and the active bending portion 12, and both the channel pipe 781B and the fluid passage pipe 782 have a circular cross-section. One end of the channel pipe 781B is fitted into the treatment tool passage 78C, and the other end of the channel pipe 781B is fitted into the treatment tool passage 48C. In addition, one end of the fluid passage pipe 782 is fitted into the fluid passage 79B, and the other end of the fluid passage pipe 782 is fitted into the fluid passage 49A. 【0108】 The treatment tool passage 78C, treatment tool passage 48C, and the treatment tool passage of the passive bending section 11 have the same shape, and the fluid passage 79B, fluid passage 49A, and the fluid passage of the passive bending section 11 also have the same shape. For the sake of explanation, only the treatment tool passage 78C and the fluid passage 79B will be described below. 【0109】 The distance from the axis of the main section 73 to the through passage is longer than the distance from the axis of the main section 73 to the treatment tool passage. In other words, the distance from the axis of the main section 73 to the axis of the fluid passage 79B is longer than the distance from the axis of the main section 73 to the axis of the treatment tool passage 78C. In other words, the fluid passage 79B is formed closer to the outer surface of the insertion section 14 than the treatment tool passage 78C. 【0110】 As shown in Figure 19, the fluid channel 79B is formed at one location P. The fluid channel 79B is formed at one location P, which includes a position separated from the center of the main section 73 by the radius of the main section 73, and the center of the fluid channel 79B lies on the line connecting the one location P and the center of the main section 73. 【0111】 In other words, the extension portion 72 is formed such that a position at a distance from the center of the main portion 73 by the radius of the main portion 73, or in other words, a position on the extension of the outer circumference of the main portion 73 (the dashed line in Figure 19), is included in the fluid passage 79B (fluid passage opening 791B) (see Figure 19). On the other hand, the center of the treatment tool passage 78C is located on a line connecting point P and the center of the main section 73, and is located closer to the center of the main section 73 than the center of the fluid passage 79B. 【0112】 The treatment instrument inserted through the channel inlet 22 (see Figure 1) exits the channel outlet 142C through the treatment instrument passage, treatment instrument passage 48C, and treatment instrument passage 78C of the passive bending section 11, and is used for diagnosis, treatment, etc., inside the body. In addition, fluid such as perfusion fluid is drawn in through the fluid passage inlet 791B and flows through the fluid passage 79B, fluid passage 49A, and the fluid passage of the passive bending section 11. 【0113】 As described above, in the endoscope 10 of Embodiment 4, the fluid passages of fluid passage 79B, fluid passage 49A, and the passive bending section 11 are formed over a wide area that includes a position that is separated from the center of the main section 73 by the radius of the main section 73. Therefore, the fluid passages of fluid passage 79B, fluid passage 49A, and the passive bending section 11 can be widely secured, and liquid suction can always be performed stably. Therefore, even in procedures such as cholangioscopy and cystoscopy, which are performed while irrigating with a fluid such as physiological saline, irrigation can be stably carried out through the fluid channel while inserting the instrument through the instrument channel. Furthermore, in procedures involving high-frequency cautery and laser irradiation, the smoke generated during cautery can be aspirated through the fluid channel while the instrument is inserted into the instrument channel, allowing for safe procedures while maintaining a clear field of view. 【0114】 Furthermore, in the endoscope 10 of Embodiment 4, as described above, the fluid passage is formed over a wide area near the edge of the insertion portion 14. Therefore, an extension portion 72 is provided to reinforce the strength associated with this, and the necessary thickness is secured between the fluid passages of the fluid passage 79B, fluid passage 49A, and passive bending portion 11 and the outer surface of the insertion portion 14. In other words, instead of increasing the diameter of the insertion section 14 itself, the extension section 72 is provided only in the parts where the fluid passages 79B, 49A, and the passive bending section 11 exist, thereby minimizing the increase in the thickness of the insertion section 14. This minimizes the burden on the patient undergoing the endoscopic examination. 【0115】 Furthermore, in the endoscope 10 of Embodiment 4, as described above, the fluid passage is formed closer to the outer surface of the insertion portion 14 than the treatment instrument passage. Therefore, when performing an endoscopic examination using the endoscope 10, the fluid from the area to be examined can be drawn in from a lower position. Consequently, the fluid flows more easily along gravity, and the fluid can be drawn in more cleanly. 【0116】 Other components of the endoscope 10 in Embodiment 4 are the same as those of the endoscope 10 in Embodiment 1, and parts similar to those in Embodiment 1 are denoted by the same reference numerals and detailed descriptions are omitted. 【0117】 The technical features (constituent elements) described in Embodiments 1 to 4 are combinable with each other, and by combining them, new technical features can be formed. The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the claims, not in the sense described above, and all modifications are intended to be in the sense and scope equivalent to the claims. [Explanation of Symbols] 【0118】 10 Endoscopes 14 Insertion part 13 Tip 48,78 Treatment Tools 79 Fluid path 131 Tip face 142 チャンネルExit L1, L2 distance 791 Fluid Intersection 48A, 48B, 48C, 78A, 78B, 78C disposal tools 49, 49A, 79A, 79B Fluid Path 72 Extended Section 73 main part 142A, 142B, 142C チャンネル Exit 791A, 791B Fluid Intersection

Claims

[Claim 1] In an endoscope having a tubular insertion section that is inserted into a body cavity, The main part has a circular cross-section, The insertion portion is provided at one location on the outer circumference of the main portion along its entire length, and comprises an extension portion that extends radially from the main portion. The main part and the extension are integrally molded parts. A through passage is formed at the aforementioned location, passing through the insertion portion in the axial direction. One end of the through passage is open to the tip surface of the insertion portion, An endoscope characterized in that fluid is drawn in through one end of the aforementioned through passage. [Claim 2] The endoscope according to claim 1, characterized in that the through passage includes one location, which is located at a distance of a radius from the center of the main part. [Claim 3] The insertion portion has an opening at one end on its tip surface, and further comprises a tool passage that penetrates the insertion portion in the axial direction, through which a treatment tool passes. The endoscope according to claim 1, characterized in that the distance from the axis of the main part to the through passage is longer than the distance from the axis of the main part to the treatment tool passage.