JP5665650B2 - Endoscope - Google Patents

Description

  The present invention relates to an endoscope provided with a fluid ejection nozzle that ejects fluid toward an observation window.

  The endoscope has an observation window for capturing the image light of the subject at the distal end of the insertion portion to be inserted into the subject, an illumination window for irradiating the subject with illumination light, and the observation window. And a fluid ejection nozzle that ejects fluid (cleaning water or air). Conventionally, the observation window is generally provided at a position where the light incident surface is exposed from the distal end surface of the insertion portion. The illumination window and the fluid ejection nozzle are arranged around the observation window. Is done. Since body fluid and dirt in the subject adhere to the surface of the observation window, the fluid is ejected from the ejection port of the fluid ejection nozzle to remove the dirt on the observation window. Further, in the endoscope described in Patent Document 1, a pair of liquid guides are extended on both sides of a region connecting the ejection port of the fluid ejection nozzle and the surface of the observation window.

Japanese Utility Model Publication No. 3-116801

  However, in the endoscope described in Patent Document 1, it is considered that the surface of the observation window is cleaned by applying cleaning water and further blown off so that water droplets do not adhere to the observation window. It is not considered to wash and wash. If the dirt adhering to the surface of the illumination window increases, the amount of light that illuminates the inside of the subject decreases, making observation difficult. Also, when using a light source device equipped with a light amount adjustment mechanism, the light amount adjustment mechanism operates to increase the amount of illumination light when the brightness in the subject decreases due to contamination of the illumination window of the endoscope. In some cases, the material at the distal end of the endoscope may deteriorate due to heat generation, or dry dirt may stick to the illumination window.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an endoscope that reliably removes dirt by flowing a fluid to the surface of an illumination window together with an observation window.

  An endoscope according to the present invention is formed at a distal end portion of an insertion portion to be inserted into a subject, provided on a flat surface perpendicular to the axial direction of the insertion portion, and the distal end portion, and observes the inside of the subject. An observation window for positioning, a first and a second illumination window for irradiating illumination light into the subject, and a distal end portion disposed at a position sandwiching the observation window therebetween, An endoscope including a fluid ejection nozzle for ejecting, wherein the tip has a step with respect to the flat surface, and surrounds the first and second illumination windows and the observation window The guide recess is arranged along a guide direction that sequentially passes through the first illumination window, the observation window, and the second illumination window from the ejection port of the fluid ejection nozzle. Inclining from the distal end side to the proximal end side to guide the fluid ejected from the ejection port And butterflies. Here, “orthogonal” includes a flat surface substantially orthogonal to the axial direction of the insertion portion.

  A flat surface perpendicular to the axial direction of the insertion portion formed at the distal end portion of the insertion portion to be inserted into the subject, an observation window provided at the distal end portion for observing the inside of the subject, and the observation A first and a second illumination window disposed at a position sandwiching a window and irradiating illumination light into the subject; and a fluid ejection nozzle provided at the tip for ejecting fluid; The first illumination window is disposed on the flat surface, the tip has a step with respect to the flat surface, the second illumination window, and the observation window The guide concave portion is formed at a position surrounding the first and second guide windows, and the guide concave portion is formed from the distal end side along the guide direction that sequentially passes through the observation window and the second illumination window from the ejection port of the fluid ejection nozzle. Inclining toward the base end side and guiding the fluid ejected from the ejection port To. Here, “orthogonal” includes a flat surface substantially orthogonal to the axial direction of the insertion portion.

  The illumination window and the observation window arranged at a position surrounded by the guide recess are provided at positions where the surface protrudes from the bottom surface of the guide recess to the tip side by a predetermined height and the surface does not protrude from the flat surface. It is preferable.

  It is preferable that the illumination window and the observation window arranged at a position surrounded by the guide recess are provided so as to be aligned with the center in the width direction of the guide recess. Moreover, it is preferable that the said guide recessed part is formed so that it may follow the outer peripheral surface of the said front-end | tip part.

The illumination window disposed at a position surrounded by the guide recess is preferably provided with a surface inclined from the distal end side to the proximal end side toward the outer peripheral surface side of the distal end portion. It is preferable that the outer peripheral surface of the tip portion and the flat surface continue smoothly, and the side surface of the guide recess and the outer peripheral surface of the tip portion continue smoothly.

  According to the endoscope of the present invention, the guide recess formed in the distal end portion of the insertion portion sequentially passes through the first illumination window, the observation window, and the second illumination window from the ejection port of the fluid ejection nozzle. Direction or from the injection port to the observation window and the second illumination window in order along the guide direction is inclined from the distal end side to the proximal end side, and guides the fluid ejected from the ejection port, together with the observation window The dirt can be reliably removed by flowing a fluid to the surface of the illumination window.

It is an external appearance perspective view of an electronic endoscope system. It is a perspective view which shows the structure of the front-end | tip part of an electronic endoscope. It is the top view which looked at the front-end | tip part from the front end side. It is sectional drawing which cut | disconnected the front-end | tip part along the guide recessed part. It is a perspective view which shows 2nd Embodiment which arranged the 1st illumination window on the flat surface, and arranged the observation window and the 2nd illumination window in the position enclosed by a guide recessed part. It is the top view which looked at the front-end | tip part of FIG. 5 from the front end side. . It is sectional drawing which cut | disconnected the front-end | tip part of FIG. 5 along the guide recessed part. It is a top view which shows the 1st modification which inclined and arrange | positioned the illumination window with respect to the observation window. It is sectional drawing along the AA line of FIG. It is a perspective view which shows 3rd Embodiment which formed the boundary of the front end surface and outer peripheral surface of a front-end | tip part smoothly. It is sectional drawing which cut | disconnected the front-end | tip part of FIG. 10 along the guide recessed part.

  As shown in FIG. 1, the electronic endoscope system 10 includes an electronic endoscope 11, a processor device 12, a light source device 13, an air / water supply device 14, and the like. The air / water supply device 14 is built in the light source device 13 and is a well-known air supply device (pump or the like) 14a for supplying air, and a washing water tank that is provided outside the light source device 13 and stores washing water. 14b. The electronic endoscope 11 is connected to a flexible insertion portion 16 that is inserted into the body of a subject, an operation portion 17 that is connected to a proximal end portion of the insertion portion 16, a processor device 12, and a light source device 13. Connector 18, and a universal cord 19 that connects between the operation unit 17 and the connector 18. The connector 18 is a composite type connector to which the processor device 12, the light source device 13, and the air / water supply device 14 are connected.

  The insertion portion 16 is provided at the distal end thereof, and includes a distal end portion 16a having a built-in CCD type image sensor (see FIG. 4; hereinafter referred to as CCD) 38 as an imaging element for in-subject imaging, and a distal end portion 16a. It comprises a bendable bending portion 16b provided continuously at the base end, and a flexible flexible tube portion 16c provided continuously at the base end of the bending portion 16b. Hereinafter, the distal end side of the insertion portion 16 is simply referred to as “distal end side”, and the proximal end side of the insertion portion 16 is simply referred to as “proximal end side”.

  The processor device 12 is electrically connected to the light source device 13 and comprehensively controls the operation of the electronic endoscope system 10. The processor device 12 supplies power to the electronic endoscope 11 via the universal cord 19 and a transmission cable inserted into the insertion portion 16 and controls the driving of the CCD 38. Further, the processor device 12 acquires an imaging signal output from the CCD 38 via a transmission cable, and performs various image processing to generate image data. The image data generated by the processor device 12 is displayed as an observation image on the monitor 20 connected to the processor device 12 by a cable.

  An air supply / water supply channel 21 (see FIG. 4) is arranged inside the insertion portion 16 and the operation portion 17, and the air supply / water supply channel 21 is provided with an air supply / water supply nozzle (provided at the tip portion 16 a). It is connected to a fluid ejection nozzle 22 (see FIGS. 2 to 4). The air / water supply channel 21 is connected to the air / water supply device 14 through the universal cord 19.

  The operation unit 17 is provided with a forceps port 23 through which various treatment tools having an injection needle, a high-frequency knife and the like are inserted, an air / water supply button 24, a bending operation knob 25, and the like. When the air supply operation is performed by the air supply / water supply button 24, the air generated by the air supply device 14a is sent to the air supply / water supply nozzle 22, and when the water supply operation is performed, the air pressure generated by the air supply device 14a is Wash water is sent from the wash water tank 14 b to the air / water feed nozzle 22. The air / water supply nozzle 22 selectively injects air and cleaning water supplied via the air / water supply channel 21.

  Further, when the bending operation knob 25 is operated, the bending portion 16b is bent in the vertical and horizontal directions by pushing and pulling the wire inserted in the insertion portion 16. Thereby, the front-end | tip part 16a is orientated in the desired direction in a body cavity.

  2, 3, and 4, the distal end portion 16 a includes a distal end portion main body 26, a cap-shaped distal end protective cap 27 that is attached to the distal end side of the distal end portion main body 26, an observation window 28, a first Second illumination windows 29 and 30, forceps outlet 31, and air / water supply nozzle 22 are provided. In the distal end portion body 26, through holes 26 a to 26 c are formed along the axial direction of the insertion portion 16 to hold components such as an air / water supply nozzle 22, an objective lens unit 36 to be described later, and a light guide 39. . The rear end of the distal end portion body 26 is connected to a bending piece 32 on the distal end side that constitutes the bending portion 16b.

  The tip protection cap 27 includes a tip plate portion 27 a that covers the tip side of the tip portion main body 26, and a cylindrical portion 27 b that covers the outer peripheral surface of the tip portion main body 26. An outer skin layer 33 covering the outer peripheral surface of the curved portion 16b extends to the distal end portion body 26, the distal end of the outer skin layer 33 and the rear end of the cylindrical portion 27b are brought into contact with each other, and the end portions are fixed with an adhesive or the like. . The distal end plate portion 27 a is formed with a flat planar surface 27 c that is located on the distal end side of the distal end portion 16 a and is orthogonal to the axial direction of the insertion portion 16. The term “orthogonal” here includes a flat surface 27 c that is substantially orthogonal to the axial direction of the insertion portion 16.

  An outer peripheral surface of the distal end plate portion 27 a, that is, an outer peripheral surface 27 d of the distal end protection cap 27 is formed in a circumferential surface shape parallel to the axial direction of the insertion portion 16. The distal end plate portion 27a has a corner portion 34 where the flat surface 27c and the outer peripheral surface 27d are connected.

  A guide recess 35 having a step on the base end side with respect to the flat surface 27c is formed in the distal end plate portion 27a. The guide recess 35 is formed to extend from a position in contact with the air / water supply nozzle 22 and is continuous with the outer peripheral surface 27d.

  Through holes 27e to 27h that expose the observation window 28, the first and second illumination windows 29 and 30, and the air / water supply nozzle 22 when the flat surface 27c is viewed from the tip side, A forceps outlet 31 is formed. The observation window 28 and the first and second illumination windows 29 and 30 are arranged at a position surrounded by the guide recess 35. Further, the first and second illumination windows 29 and 30 are arranged at positions sandwiching the observation window 28 therebetween.

  The observation window 28 is a state-of-the-art objective lens that constitutes the objective lens unit 36, and also serves as a cover glass. The observation window 28 has a substantially disk-like outer shape, and has a surface 28a that is a light incident surface and an outer peripheral surface 28b continuous with the surface 28a, and the planar surface 28a is parallel to the flat surface 27c, that is, inserted. It is arranged at a position orthogonal to the axial direction of the portion 16.

  The optical system of the objective lens unit 36 including the observation window 28 is held by a lens barrel 37. The lens barrel 37 holds the proximal end side of the outer peripheral surface 28 b of the observation window 28. In the observation window 28, the distal end side of the outer peripheral surface 28 b is fitted in the through hole 27 e of the distal protection cap 27. The lens barrel 37 is fitted to the through hole 26 b of the tip end body 26 and attached so that the tip end face abuts the tip plate portion 27 a of the tip protection cap 27.

  A CCD 38 is attached to the back of the objective lens unit 36. The CCD 38 is composed of, for example, an interline transfer type CCD, and a subject image captured by the optical system of the objective lens unit 36 is formed on the imaging surface. The image sensor is not limited to the CCD 38, and may be a CMOS.

  The first and second illumination windows 29 and 30 also serve as irradiation lenses, and irradiate the observation site in the subject with illumination light from the light source device 13. These illumination windows 29, 30 are arranged such that planar surfaces 29a, 30a serving as light output surfaces are parallel to the surface 28a of the observation window 28, that is, at positions orthogonal to the axial direction of the insertion portion 16. The light guide 39 has an emission end facing the side. The light guide 39 is formed by bundling a large number of optical fibers, fitting a base on the distal end side, and covering the outer peripheral surface with a tube. The light guide 39 passes through the insertion portion 16, the operation portion 17, the universal cord 19, and the connector 18, and guides the illumination light from the light source device 13 to the first and second illumination windows 29 and 30. The forceps outlet 31 is connected to a forceps channel (not shown) disposed in the insertion portion 16 and communicates with the forceps port 23 of the operation portion 17. The tips of various treatment tools inserted through the forceps port 23 are exposed from the forceps outlet 31.

  The air / water supply nozzle 22 is integrally formed with an injection cylinder portion 22a on the distal end side and a connection cylinder portion 22b on the proximal end side. The connecting cylinder portion 22 b is connected to the air / water supply channel 21 by being fitted to the outer peripheral surface on the front end side of the air / water supply channel 21. Further, the connecting cylinder part 22 b and the air / water supply channel 21 are fitted in the through hole 26 a of the tip end body 26. The injection cylinder portion 22 a is formed in a cylindrical shape that is smoothly bent from the connection cylinder portion 22 b to the injection port 40 at the tip, and is exposed to the outside through the through hole 27 h of the tip protection cap 27.

  The guide recess 35 includes a bottom surface 35a that surrounds the observation window 28 and the first and second illumination windows 29 and 30, and side surfaces 35b and 35c that extend substantially vertically from both sides of the bottom surface 35a and connect to the flat surface 27c. The bottom surface 35a is inclined from the distal end side to the proximal end side along the guide direction passing in order from the injection port 40 of the air / water feeding nozzle 22 through the first illumination window 29, the observation window 28, and the second illumination window 30. Then, the fluid ejected from the ejection port 40 together with the side surfaces 35b and 35c is guided.

  In addition, since the injection port 40 of the air / water supply nozzle 22, the first illumination window 29, the observation window 28, and the second illumination window 30 are arranged in a curved line in consideration of a reduction in the diameter of the distal end portion 16a. When the flat surface 27 c is viewed from the front end side, the bottom surface 35 a is formed in a curved shape that matches the arrangement of the injection port 40, the first illumination window 29, the observation window 28, and the second illumination window 30. .

  Since the outer diameters of the observation window 28 and the illumination windows 29 and 30 are larger than the dimension in the width direction of the injection port 40 of the air / water supply nozzle 22, the side surfaces 35b and 35c gradually move from the injection port 40 toward the outer peripheral surface 27d. The distance between each other is wide. In addition, the air supply / water supply nozzle 22 has a jetting direction S <b> 1 so as to spray fluid from obliquely above the bottom surface 35 a of the guide recess 35 and the surface 28 a of the observation window 28.

  Symbol CL1 is a line that bisects the center line of the guide recess 35, that is, the distance between the side surfaces 35b and 35c, and the observation window 28 and the illumination windows 29 and 30 are provided with their center positions aligned on the center line CL1. ing.

  Reference numerals H1, H2, and H3 indicate predetermined heights at which the surfaces 29a, 28a, and 30a of the first illumination window 29, the observation window 28, and the second illumination window 30 protrude from the bottom surface 35a. The predetermined height from the bottom surface 35a at the center position of each of the surfaces 29a, 28a, 30a. Further, symbols D1, D2, and D3 indicate the depths from the flat surface 27c to the bottom surface 35a at the respective center positions of the first illumination window 29, the observation window 28, and the second illumination window 30. The first illumination window 29, the observation window 28, and the second illumination window 30 have positions where their surfaces protrude from the bottom surface 35a by a predetermined height and do not protrude from the flat surface 27c, that is, D1> H1, D2>. They are arranged at positions where H2 and D3> H3, respectively. Accordingly, it is possible to reliably flow the fluid to the surfaces 29a, 28a, and 30a of the first illumination window 29, the observation window 28, and the second illumination window 30, and from the observation window 28 to the inside of the subject. The guide recess 35 does not enter the observation range where the image light is captured, and the illumination light emitted from the illumination windows 29 and 30 into the subject is not blocked by the guide recess 35.

  A process when the observation window 28 and the illumination windows 29 and 30 are cleaned by fluid ejection from the air / water supply nozzle 22 using the electronic endoscope 11 having the above configuration will be described. The fluid (air or washing water) ejected from the air / water feeding nozzle 22 hits the guide recess 35 and the surface 28 a of the observation window 28. Further, the fluid guided by the guide recess 35 flows in order through the surfaces 29a, 28a, 30a of the first illumination window 29, the observation window 28, and the second illumination window 30, and then flows to the outer peripheral surface 27d. As a result, dirt such as body fluids and dirt attached to the surfaces of the observation window 28 and the illumination windows 29 and 30 is removed. Further, the cleaning water is also removed by the jet of air.

  As described above, the fluid ejected from the air / water feeding nozzle 22 is guided by the guide recess 35 and to the surfaces 29a and 30a of the first and second illumination windows 29 and 30 together with the surface 28a of the observation window 28. It can flow and be washed reliably. Each surface 29a, 28a, 30a of the first illumination window 29, the observation window 28, and the second illumination window 30 protrudes from the bottom surface 35a of the guide recess 35 by a predetermined height and does not protrude from the flat surface 27c. Since it is arranged at the position, the fluid passing through the guide recess 35 surely hits each surface 29a, 28a, 30a.

  In the first embodiment, the first illumination window 29, the observation window 28, and the second illumination window 30 are positions where the respective surfaces 29a, 28a, 30a protrude from the bottom surface 35a of the guide recess 35 by a predetermined height. However, the present invention is not limited to this, and the first illumination window 29, the observation window 28, and the second illumination window 30 are arranged at positions where the respective surfaces 29a, 28a, 30a are flush with the bottom surface 35a. May be.

  In the first embodiment, the first and second illumination windows 29 and 30 are disposed in the position surrounded by the guide recess 35 together with the observation window 28. However, the present invention is not limited to this, and FIG. 6 and 7, the first illumination window 29 is disposed on the flat surface 50 a, and the second illumination window 30 and the observation window 28 are surrounded by a position like the tip 50 of the second embodiment shown in FIGS. 6 and 7. A guide recess 51 may be formed. 5, 6, and 7, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  In the second embodiment, the first and second illumination windows 29 and 30 are arranged at positions sandwiching the observation window 28 as in the first embodiment, and the respective surfaces 29a and 30a are the observation windows 28. Is arranged in parallel with the surface 28a of the. The flat surface 50 a is formed on the distal end side of the distal end portion 50 and is orthogonal to the axial direction of the insertion portion 16, similarly to the flat surface 27 c of the first embodiment. Moreover, the front-end | tip part 50 has the corner | angular part 52 which the flat surface 50a and the outer peripheral surface 50b connect.

  The guide recess 51 is formed to extend from a position in contact with the air / water supply nozzle 22 and is continuous with the outer peripheral surface 50b. The guide recess 51 has a step with respect to the flat surface 50a, a bottom surface 51a surrounding the observation window 28 and the second illumination window 30, and a side surface 51b extending substantially vertically from both sides of the bottom surface 51a and connected to the flat surface 50a. , 51c. The bottom surface 51a is inclined from the distal end side to the proximal end side along the guide direction passing through the injection port 40 of the air / water feeding nozzle 22 in order from the observation window 28 and the second illumination window 30, and together with the side surfaces 51b and 51c. The fluid ejected from the ejection port 40 is guided. The bottom surface 51 a is formed in a curved shape that matches the arrangement of the ejection ports 40, the observation window 28, and the second illumination window 30. The distance between the side surfaces 51b and 51c gradually increases from the injection port 40 toward the outer peripheral surface 50b.

  Reference sign CL2 is a line that bisects the center line of the guide recess 51, that is, the distance between the side surfaces 51b and 51c, and the observation window 28 and the second illumination window 30 are provided with their center positions aligned on the center line CL2. It has been. The observation window 28 and the second illumination window 30 are disposed at positions where the surfaces protrude from the bottom surface 51a by a predetermined height and the surfaces do not protrude from the flat surface 27c.

  In the present embodiment, the air supply / water supply nozzle 22 has a jetting direction S <b> 2 so as to spray fluid from the bottom surface 51 a of the guide recess 51 and the surface 28 a of the observation window 28 obliquely above.

  When the fluid ejected from the air / water feeding nozzle 22 hits the guide recess 35 and the surface 28a of the observation window 28, the fluid guided by the guide recess 35 is in contact with the surfaces 28a and 30a of the observation window 28 and the second observation window 30, respectively. In order and flow to the outer peripheral surface 50b. This removes dirt such as bodily fluids and dirt attached to at least the surface 30a of the second illumination window 30 together with the surface 28a of the observation window 28. For example, dirt adheres to the surface 29a of the first illumination window 29. Even if it is, the surface 30a of the second illumination window 30 can remove the dirt, and can illuminate the inside of the subject.

  In the second embodiment, the observation window 28 and the second illumination window 30 are arranged at positions where the surfaces 28a and 30a protrude from the bottom surface 51a of the guide recess 51 by a predetermined height. Not limited to this, the observation window 28 and the second illumination window 30 may be arranged at positions where the front surfaces 28a and 30a are flush with the bottom surface 51a.

  In the first and second embodiments, the surfaces of the illumination windows 29 and 30 are arranged in parallel with the surface 28a of the observation window 28. However, the present invention is not limited to this, and is shown in FIGS. As in the distal end portion 55 of the modification, the surfaces of the illumination windows 29 and 30 may be inclined from the distal end side to the proximal end side toward the outer peripheral surface 55b side. In FIGS. 8 and 9, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  In the modification shown in FIGS. 8 and 9, as in the first and second embodiments, a flat surface 55a is formed on the tip side of the tip portion 55, and there is a step with respect to the flat surface 55a. A guide recess 56 surrounding the window 28 and the second illumination window 30 is formed. The guide recess 56 is formed to extend from a position in contact with the air / water supply nozzle 22 and is continuous with the outer peripheral surface 55b. The observation window 28 has a surface 28a arranged in parallel with the flat surface 55a, as in the first and second embodiments. Furthermore, the tip portion 55 has a corner portion 57 where the flat surface 55a and the outer peripheral surface 55b are connected. In this modification, the surface 30a of the second illumination window 30 is parallel to the bottom surface 56a of the guide recess 56, that is, inclined from the distal end side to the proximal end side toward the outer peripheral surface 55b side. Thereby, when the fluid is ejected from the air / water feeding nozzle 22 to the observation window 28 and the guide recess 56, the resistance of the fluid flowing through the guide recess 56 is reduced, and the fluid smoothly flows from the ejection port 40 toward the outer peripheral surface 55b. It can be made to flow. Further, in this modification, the distal end portion 55 is formed with an inclined surface 55c that is inclined from the distal end side to the proximal end side from the flat surface 55a toward the outer peripheral surface 55b, and the first illumination window 29 is inclined. It is arranged at a position surrounded by the surface 55c and is disposed in parallel with the inclined surface 55c.

  In the said 1st and 2nd embodiment, although it has the corner | angular parts 34, 52, and 57 where the flat surfaces 27c, 50a, and 55a of the front-end | tip parts 16a, 50, and 55 and the outer peripheral surfaces 27d, 50b, and 55b are connected, this invention. However, the present invention is not limited to this, and the flat surface 60a and the outer peripheral surface 60b may be formed so as to be smoothly continuous like the tip portion 60 of the modification shown in FIGS. In this case, the connecting surface 62 connecting the flat surface 60a and the outer peripheral surface 60b is a curved surface. The guide recess 61 provided at the tip 60 is formed so as to extend from a position in contact with the air / water supply nozzle 22 and is continuous with the outer peripheral surface 60b. Further, the side surfaces 61b and 61c of the guide recess 61 and the outer peripheral surface 60b of the tip 60 are formed so as to be smoothly continuous. Thereby, the tip portion 60 has no corner portion, and can be smoothly inserted into the subject.

  In each of the above embodiments, the observation window 28 and the illumination windows 29 and 30 having a planar surface are used. However, the present invention is not limited to this, and the observation window having a convex lens surface whose surface is convex toward the tip side. Or, an illumination window may be used. In this case, the observation window and the illumination window arranged at positions surrounded by the guide recesses 35, 51, 56, and 61 of the distal end portions 16a, 50, 55, and 60 are such that the leading end of the convex lens surface is the guide recesses 35, 51, and 56. , 61 protrudes from the bottom surfaces 35a, 51a, 56a, 61a by a predetermined height and is disposed at a position not protruding from the flat surfaces 27c, 50a, 55a, 60a.

  In each of the above embodiments, an electronic endoscope that observes an image obtained by imaging the state of a subject using an image sensor has been described as an example. However, the present invention is not limited to this and is not limited to an optical endoscope. The present invention can also be applied to an endoscope that employs an image guide to observe the state of a subject.

DESCRIPTION OF SYMBOLS 10 Electronic endoscope system 11 Electronic endoscope 16 Insertion part 16a, 50, 55, 60 Tip part 21 Air supply / water supply channel 22 Air supply / water supply nozzle 27c, 50a, 55a, 60a Flat surface 27d, 50b, 55b, 60b Outer peripheral surface 28 Observation window 29 First illumination window 30 Second illumination window 35, 51, 56, 61 Guide recess 35a, 51a, 56a, 61a Bottom surface 35b, 35c, 51b, 51c, 56b, 56c, 61b, 61c Side 40 injection port

Claims (7)

A flat surface formed at the distal end of the insertion portion to be inserted into the subject and orthogonal to the axial direction of the insertion portion;
An observation window provided at the tip, for observing the inside of the subject;
A first and a second illumination window disposed at a position sandwiching the observation window, and irradiating illumination light into the subject;
In an endoscope provided with a fluid ejection nozzle provided at the distal end portion for ejecting fluid,
The tip has a step with respect to the flat surface, and a guide recess is formed at a position surrounding the first and second illumination windows and the observation window,
The guide recess is inclined from the distal end side to the proximal end side along a guide direction that sequentially passes through the first illumination window, the observation window, and the second illumination window from the ejection port of the fluid ejection nozzle, An endoscope that guides fluid ejected from the ejection port. A flat surface formed at the distal end of the insertion portion to be inserted into the subject and orthogonal to the axial direction of the insertion portion;
An observation window provided at the tip, for observing the inside of the subject;
A first and a second illumination window disposed at a position sandwiching the observation window, and irradiating illumination light into the subject;
In an endoscope provided with a fluid ejection nozzle provided at the distal end portion for ejecting fluid,
The first illumination window is disposed on the flat surface,
The tip has a step with respect to the flat surface, and a guide recess is formed at a position surrounding the observation window and the second illumination window.
The guide recess is inclined from the distal end side to the proximal end side along a guide direction that sequentially passes through the observation window and the second illumination window from the ejection port of the fluid ejection nozzle, and is ejected from the ejection port. An endoscope characterized by guiding a fluid.   The illumination window and the observation window surrounded by the guide recess are provided at a position where the surface protrudes from the bottom surface of the guide recess to the tip side by a predetermined height and the surface does not protrude from the flat surface. The endoscope according to claim 1 or 2.   The said illumination window and the said observation window enclosed by the said guide recessed part are aligned and provided in the center line of the width direction of the said guide recessed part, The any one of Claims 1-3 characterized by the above-mentioned. Endoscope.   The endoscope according to any one of claims 1 to 4, wherein the guide recess is formed so as to be continuous with an outer peripheral surface of the tip portion. 6. The illumination window surrounded by the guide recess is provided with a surface inclined from the distal end side to the proximal end side toward the outer peripheral surface side of the distal end portion. The endoscope according to item 1. The outer peripheral surface of the tip portion and the flat surface are smoothly continuous, and the side surface of the guide recess and the outer peripheral surface of the tip portion are smoothly continuous. The endoscope according to item.

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