Endoscope

Abstract

The present invention provides an endoscope capable of improving the cleanability of both sides of an observation window. On the front end surface (28) of the endoscope (10), a fluid guide portion (60) composed of a raised portion (62) is provided between a fluid injection nozzle (40) and an observation window (34), and a portion of the fluid injected from an injection port (52) is guided toward both sides (34A, 34B) of the observation window (34) via a pair of first guide surfaces (66, 68) formed on both sides of a top (64) of the raised portion (62).

Description

Technical Field

[0001] The present invention relates to an endoscope, and more particularly to an endoscope that cleans an observation window disposed on a distal end surface of an insertion portion by using a fluid ejected from a fluid ejection nozzle. Background Art

[0002] The distal end of the insertion portion of the endoscope is equipped with an observation window for receiving light from the observed area and an illumination window for illuminating the observed area. Furthermore, the distal end is equipped with a fluid ejection nozzle (also known as a fluid ejection nozzle or an air and water supply nozzle) that ejects a cleaning fluid (e.g., water) and a gas (e.g., air) toward the observation window to remove deposits such as body fluids.

[0003] When cleaning the observation window, first, cleaning liquid is ejected from the ejection port of the fluid ejection nozzle to remove debris adhering to the observation window, and then, gas is ejected from the ejection port to remove the cleaning liquid remaining on the observation window.

[0004] Patent Document 1 discloses an endoscope that allows fluid ejected from an injection port to flow through the observation window and an adjacent area adjacent to the observation window during cleaning of the observation window. This endoscope comprises a fluid guide portion disposed between the fluid ejection nozzle and the observation window; a first fluid path that directs a portion of the fluid guided by the fluid guide portion to the observation window; and a second fluid path that directs fluid that has deviated from the fluid guide portion to the adjacent area.

[0005] Previous technical literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2016-202707 Summary of the Invention

[0008] Technical issues to be solved by the invention

[0009] In the field of endoscopy, there is a trend toward smaller diameters of the insertion portion of endoscopes to reduce the burden on the subject. Furthermore, along with this trend, miniaturization is also required for the observation window and fluid injection nozzle located at the distal end of the insertion portion. However, there is also a demand for obtaining images over a wide range at a larger observation angle. In this case, it is desirable to use an observation window with a diameter as large as possible.

[0010] Here, when the sizes of the injection port of the fluid injection nozzle and the observation window are compared in a direction perpendicular to a straight line connecting the center of the injection port and the center of the observation window, usually, the size of the injection port (equivalent to the opening width of the injection port) is smaller than the size of the observation window (equivalent to the diameter of the observation window).

[0011] Therefore, when the injection port becomes further smaller than the observation window due to the above-mentioned miniaturization trend, the fluid from the injection port toward the observation window only flows toward the central part of the observation window, and it is difficult for the fluid to flow toward the outer periphery of the observation window in the above-mentioned orthogonal direction (hereinafter referred to as the two side parts). Therefore, the problem of reduced cleanability of the two side parts of the observation window may arise.

[0012] The present invention has been made in view of such circumstances, and an object of the present invention is to provide an endoscope capable of improving the cleanability of both side portions of an observation window.

[0013] Means for solving technical problems

[0014] In order to achieve the above-mentioned purpose, the endoscope involved in the present invention comprises: an insertion portion having a front end, a base end and a longitudinal axis; an operating portion arranged at the base end of the insertion portion; a front end face arranged at the front end of the insertion portion; an observation window arranged on the front end face; a fluid injection nozzle arranged on the front end face and injecting fluid from an injection port opening toward the observation window; and a fluid guide portion arranged between the fluid injection nozzle and the observation window and guiding the fluid injected from the injection port toward the observation window, the fluid guide portion being arranged on an extension portion of the opening area of the injection port extended in the fluid injection direction, and being composed of a raised portion raised from the front end side in the longitudinal axis direction of the front end face, the raised portion comprising: a top formed on the front end side in the longitudinal axis direction of the raised portion; and a pair of first guide surfaces respectively formed on both sides of the top in a direction perpendicular to a straight line connecting the center of the injection port and the center of the observation window, and guiding a portion of the fluid injected from the injection port to both sides of the observation window in the orthogonal direction.

[0015] In one aspect of the present invention, the pair of first guide surfaces are preferably formed of inclined surfaces including a component oblique to the longitudinal axis and extending from a straight line to a direction perpendicular to the vertical axis as moving from the fluid ejecting nozzle toward the observation window.

[0016] In one embodiment of the present invention, the raised portion preferably includes a second guide surface provided between the fluid ejecting nozzle and the top portion and guiding a portion of the fluid ejected from the ejection port toward the center of the observation window via the top portion.

[0017] In one aspect of the present invention, it is preferable that the second guide surface is formed of an inclined surface that is inclined toward the distal end side in the longitudinal axis direction as it moves from the fluid ejecting nozzle toward the observation window.

[0018] In one aspect of the present invention, it is preferable that the pair of first guide surfaces and the second guide surfaces are connected to each other via a curved ridge portion.

[0019] In one aspect of the present invention, it is preferable that each of the pair of first guide surfaces and the second guide surface includes a streamlined curved surface.

[0020] In one aspect of the present invention, the fluid guide portion preferably includes a flat third guide surface between the top portion and the observation window.

[0021] In one aspect of the present invention, the front shape of the fluid guide portion when viewed from the longitudinal direction is preferably a trapezoidal shape that expands from a straight line toward a direction orthogonal thereto as it moves from the fluid ejecting nozzle toward the observation window.

[0022] In one embodiment of the present invention, the fluid guide portion preferably has a fourth guide surface, which guides the fluid ejected from the injection port that deviates from a pair of first guide surfaces toward both sides of the observation window and is formed by an inclined surface that includes a component oblique to the longitudinal axis and expands from a straight line to an orthogonal direction as it moves toward the two sides.

[0023] In one embodiment of the present invention, when the maximum inclination angle of the second guide surface is set to d, the maximum inclination angle of a pair of first guide surfaces is set to β, and the maximum inclination angle of the fourth guide surface is set to γ, the respective maximum inclination angles of the pair of first guide surfaces, the second guide surface and the fourth guide surface relative to the front end surface are in the relationship of α>β>γ.

[0024] In one embodiment of the present invention, when the fluid injection nozzle, the raised portion and the observation window are observed from a direction perpendicular to the longitudinal axis, the observation window is arranged on a first extended area of the front end area on the front end side of the longitudinal axis in the opening area of the injection port extended in the direction of the fluid injection, and the raised portion is arranged on a second extended area of the base end area on the base end side closer to the longitudinal axis than the front end area is extended in the direction of the fluid injection.

[0025] In one aspect of the present invention, when the observation window is viewed from the front in the longitudinal direction, the extended region extending the opening region of the ejection port in the fluid ejection direction is preferably formed on the observation window at an inner side than the outer periphery of the observation window.

[0026] In one aspect of the present invention, the injection port preferably includes an expansion portion in which the opening width expands in a direction perpendicular to the observation window as it moves toward the observation window.

[0027] Effects of the Invention

[0028] According to the present invention, the cleaning properties of both side portions of the observation window can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is an overall view of an endoscope according to an embodiment.

[0030] Figure 2 Yes Figure 1 A perspective view of the structure of the front end surface of the insertion portion of the endoscope shown.

[0031] Figure 3 yes Figure 2 The front view of the front end is shown.

[0032] Figure 4 It is along Figure 2 Cross-sectional view taken along line IV-IV.

[0033] Figure 5 It is a plan view showing a fluid path of a fluid guided by a fluid guide portion.

[0034] Figure 6 It is an explanatory diagram showing the maximum inclination angles of a plurality of guide surfaces constituting a fluid guide portion.

[0035] Figure 7 This is a cross-sectional view of the injection port, the raised portion, and the observation window as viewed from a direction perpendicular to the vertical axis. DETAILED DESCRIPTION

[0036] Hereinafter, the endoscope according to the present invention will be described with reference to the accompanying drawings.

[0037] Figure 1 It is an overall view of the endoscope 10 according to the embodiment of the present invention.

[0038] like Figure 1 As shown, the endoscope 10 includes an insertion portion 12 inserted into a subject, an operation portion 14 provided at the base end of the insertion portion 12, and a universal cable 16 connecting the endoscope 10 to system components such as a light source device, a processor device, and an air and water supply device (not shown).

[0039] The insertion portion 12 has a distal end, a proximal end, and a longitudinal axis A, and includes a soft portion 18 , a bending portion 20 , and a distal end portion 22 in this order from the proximal end toward the distal end.

[0040] The soft portion 18 is flexible and can be bent in any direction along the insertion path of the insertion portion 12. The bending portion 20 is bent in the vertical direction and the left-right direction respectively by operating the angle knobs 24 and 26 that are freely rotatable and provided on the operation portion 14, and the direction of the front end portion 22 can be changed in any direction. In addition, the front end portion 22 has a front end surface 28 provided at the front end of the insertion portion 12 (see Figure 2 ).

[0041] Figure 2 2 is an enlarged perspective view showing the front end portion 22. Figure 3 From the vertical axis A (reference Figure 1 ) direction observed from the front of the front end 22 of the main view. And, Figure 4 It is along Figure 2 sectional view of the front end portion 22 taken along line IV-IV.

[0042] like Figure 4As shown, the front end portion 22 includes a front end portion body 30 made of a hard material such as metal and holding various components arranged in the front end portion 22, and a front end cover 32 made of an insulating resin material and covering the front end surface 30A and the front end outer peripheral surface 30B of the front end portion body 30. Figure 4 In the figure, as components held by the front end body 30 and the front end cover 32, a lens barrel 38 accommodating an observation window 34 and an optical system 36 constituting the observation portion and a front end portion 42A of an air and water supply channel 42 connected to a fluid ejection nozzle 40 are shown.

[0043] like Figure 2 and Figure 3 As shown, the front end face 28 is formed on the front end side of the front end cover 32. The front end face 28 is composed of a substantially circular flat surface perpendicular to the longitudinal axis A. The lighting windows 44, 46, the observation window 34, the treatment instrument outlet 48 and the above-mentioned fluid injection nozzle 40 are arranged at predetermined positions on the front end face 28. Figure 2 and Figure 3 The symbol C shown indicates the center of the front end face 28 .

[0044] The lighting windows 44 and 46 are components of an illumination unit for illuminating the observed area, and irradiate the observed area with the illumination light transmitted from the light source device.

[0045] The circular surfaces 44S and 46S of the illumination windows 44 and 46 are formed, for example, of flat surfaces and are arranged perpendicular to the longitudinal axis A. Furthermore, the centers of the surfaces 44S and 46S are arranged at positions offset toward the periphery of the front end surface 28 relative to the center C of the front end surface 28 , and are arranged at positions opposing each other across the center B of the surface 34S of the observation window 34 .

[0046] The observation window 34 is a component of the observation unit for acquiring an image of the observed part, and transmits the subject light from the observed part through the observation window. Figure 4 The optical system 36 shown is captured by a solid-state imaging element or an image guide (not shown). The image captured by the observation unit is sent to the processor device as an observation image.

[0047] The circular surface 34S of the observation window 34 is formed, for example, by a flat surface and is arranged perpendicular to the optical axis D of the observation portion. Furthermore, the center B of the surface 34S is arranged at a position offset toward the periphery of the distal end face 28 relative to the center C of the distal end face 28. Furthermore, the optical axis D is substantially parallel to the longitudinal axis A, and the center B is located on the optical axis D.

[0048] The treatment instrument outlet 48 is inserted through the insertion portion 12 (see Figure 1) is connected to the treatment instrument introduction port 50 of the operation portion 14. Therefore, the treatment instrument introduced from the treatment instrument introduction port 50 is led out from the treatment instrument lead-out port 48 via the treatment instrument insertion channel.

[0049] Furthermore, a suction channel (not shown) is connected to the treatment instrument insertion channel, and the operation portion 14 (see FIG. Figure 1 ) is operated to perform suction from the treatment instrument outlet 48 via the suction channel.

[0050] like Figure 4 As shown, the fluid ejecting nozzle 40 includes a base end portion 40A and a tip portion 40B, and is configured in an L-shape including the base end portion 40A and the tip portion 40B.

[0051] The base end portion 40A constitutes a connection portion connected to the front end portion 42A of the air and water supply channel 42, and is connected to the above-mentioned air and water supply device via the air and water supply channel 42. In addition, the cross section of the pipe 41A of the base end portion 40A, which is perpendicular to the axis of the pipe 41A, is formed into a circle, and the center E of the circle is arranged relative to the center C of the front end surface 28 (refer to Figure 3 ) is located at a position biased toward the periphery of the front end surface 28, and is arranged at a position close to the lighting window 46 among the lighting windows 44 and 46 in order to avoid interference with the treatment instrument guide outlet 48.

[0052] The pipe 41B of the front end portion 40B has a rectangular cross section perpendicular to the axis of the pipe 41B. The pipe 41B has an injection port 52 formed at the front end thereof, opening toward the observation window 34. The injection port 52 is a rectangular opening similar to the cross section of the pipe 41B.

[0053] According to the fluid ejection nozzle 40 configured as described above, if the fluid ejection nozzle 40 formed on the operation portion 14 (see FIG. Figure 1 ) is opened through the leak hole (not shown) of the air and water supply button 56, gas from the air and water supply device is ejected from the ejection port 52 toward the surface 34S of the observation window 34. Furthermore, when the air and water supply button 56 is pressed with a finger that has closed the leak hole, cleaning liquid from the air and water supply device is ejected from the ejection port 52 toward the surface 34S of the observation window 34. Furthermore, as a sequence for cleaning the observation window 34, for example, after cleaning liquid is ejected from the ejection port 52 to remove deposits such as blood or body fluids adhering to the surface 34S of the observation window 34, gas is ejected from the ejection port 52 to remove the cleaning liquid remaining on the surface 34S of the observation window 34.

[0054] Next, the structure of the front end surface 28, in particular, the mechanism related to the flow path of the fluid ejected from the ejection port 52, will be described in detail.

[0055] like Figures 2 to 4 As shown, a fluid guide portion 60 is provided on the front end face 28 to guide the fluid ejected from the ejection port 52 toward the observation window 34 and the like. The fluid guide portion 60 is provided between the fluid ejection nozzle 40 and the observation window 34 and extends from the rectangular opening area of the ejection port 52 in the direction of fluid ejection. The fluid guide portion 60 is formed by a raised portion 62 that rises from the front end face 28 toward the front end in the direction of the longitudinal axis A.

[0056] The raised portion 62 has a top portion 64 formed on the front end side of the raised portion 62 in the direction of the longitudinal axis A. Figure 3 As shown, the raised portion 62 has a pair of first guide surfaces 66, 68. The pair of first guide surfaces 66, 68 are respectively formed on both sides of the top 64 in the direction of arrow H, which is perpendicular to the straight line G connecting the center F of the opening area of the injection port 52 and the center B of the observation window 34. The pair of first guide surfaces 66, 68 function as guide surfaces for guiding a portion of the fluid ejected from the injection port 52 to the two side portions 34A, 34B of the observation window 34 in the direction of arrow H in the surface 34S of the observation window 34. In addition, as an example, in Figure 3 , the center C is located on the straight line G, but the present invention is not limited thereto. The center C may be deviated from the straight line G.

[0057] As an example, the pair of first guide surfaces 66 and 68 are formed by inclined surfaces that include a component oblique to the longitudinal axis A and that expand from the straight line G in the direction of the arrow H as they extend from the fluid ejecting nozzle 40 toward the observation window 34. The inclined surfaces described above are merely examples, and may be formed by surfaces of other shapes as long as they are capable of guiding the fluid toward the two side portions 34A and 34B of the observation window 34.

[0058] The raised portion 62 also includes a second guide surface 70 . The second guide surface 70 is provided between the fluid ejecting nozzle 40 and the top portion 64 and functions as a guide surface for guiding a portion of the fluid ejected from the ejection port 52 toward the central portion 34C of the observation window 34 via the top portion 64 .

[0059] As an example, the second guide surface 70 is formed by an inclined surface that inclines toward the front end side in the direction of the longitudinal axis A as it moves from the fluid ejecting nozzle 40 toward the observation window 34. The inclined surface described above is an example, and may be formed by another surface as long as it has a shape that can guide the fluid toward the central portion 34C of the observation window 34.

[0060] Furthermore, the pair of first guide surfaces 66, 68 and the second guide surface 70 are connected via curved ridges 72, 74 (see Figure 5 ) are connected to each other. In addition, the pair of first guide surfaces 66, 68 and the second guide surface 70 are respectively composed of surfaces including streamlined curved surfaces.

[0061] Next, the function of the fluid guide portion 60 including the first guide surfaces 66 and 68 and the second guide surface 70 will be described.

[0062] Figure 5 It is a plan view showing a plurality of fluid paths of the fluid guided by the fluid guide portion 60 using arrows.

[0063] like Figure 5 As shown, a portion of the fluid ejected from the ejection port 52 of the fluid ejection nozzle 40, specifically, the fluid ejected from a position spaced apart from the center F of the ejection port 52 in the direction of arrow H, flows from the second guide surface 70 via the ridges 72 and 74 to the pair of first guide surfaces 66 and 68 as indicated by first fluid paths 90 and 92 indicated by arrows J and K. The fluid is then guided by the pair of first guide surfaces 66 and 68 toward the two side portions 34A and 34B of the observation window 34, flowing toward the two side portions 34A and 34B. Thus, the two side portions 34A and 34B of the observation window 34 are cleaned by the fluid flowing along the first fluid paths 90 and 92.

[0064] Thus, according to the endoscope 10 of the embodiment, in the front end surface 28 of the insertion portion 12, the fluid guide portion 60 composed of the raised portion 62 is arranged between the fluid injection nozzle 40 and the observation window 34, and is constructed to guide a portion of the fluid injected from the injection port 52 to the two side portions 34A and 34B of the observation window 34 through a pair of first guide surfaces 66 and 68 respectively formed on both sides of the top 64, thereby improving the cleanability of the two side portions 34A and 34B of the observation window 34.

[0065] Furthermore, the pair of first guide surfaces 66 and 68 of the embodiment are formed by inclined surfaces including a component oblique to the longitudinal axis A and extending in the direction of arrow H as moving from the fluid injection nozzle 40 toward the observation window 34, thereby being able to smoothly guide the fluid to the two side portions 34A and 34B of the observation window 34.

[0066] On the other hand, as shown by the second fluid path 94 indicated by the arrow L, the fluid ejected from the center F of the ejection port 52 and its vicinity is guided by the second guide surface 70 through the top portion 64 to the central portion 34C of the observation window 34 and flows toward the central portion 34C. Thus, the central portion 34C of the observation window 34 is cleaned by the fluid flowing along the second fluid path 94.

[0067] Furthermore, the second guide surface 70 of the embodiment is formed as an inclined surface that inclines toward the distal end in the longitudinal axis A direction from the fluid ejecting nozzle 40 toward the observation window 34 , thereby smoothly guiding the fluid toward the central portion 34C of the observation window 34 .

[0068] Furthermore, the pair of first guide surfaces 66, 68 and the second guide surface 70 are connected to each other via the curved ridges 72, 74. Therefore, the fluid flowing along the first fluid paths 90, 92 flows smoothly from the second guide surface 70 toward the pair of first guide surfaces 66, 68 via the ridges 72, 74. Thus, the fluid can be effectively guided toward the two side portions 34A, 34B of the observation window 34.

[0069] Furthermore, the pair of first guide surfaces 66 and 68 include streamlined curved surfaces, thereby enabling the fluid to be smoothly guided from the pair of first guide surfaces 66 and 68 toward the two side portions 34A and 34B of the observation window 34. Similarly, the second guide surface 70 also includes streamlined curved surfaces, thereby enabling the fluid to be smoothly guided from the second guide surface 70 toward the center portion 34C of the observation window 34. By configuring the first guide surfaces 66 and 68 and the second guide surface 70 to include such streamlined surfaces, even when the fluid violently collides with the pair of first guide surfaces 66 and 68 and the second guide surface 70, splashing of the fluid can be suppressed, thereby enabling the majority of the fluid ejected from the ejection port 52 to be effectively utilized for cleaning the observation window 34.

[0070] The streamlined surface is, for example, a curved surface that bulges smoothly from the front end face 28 toward the front end side of the longitudinal axis A. Furthermore, in addition to being constituted solely by the streamlined surfaces, the first guide surfaces 66 , 68 and the second guide surface 70 may be surfaces formed by connecting streamlined surfaces with flat surfaces, as long as they can smoothly guide the fluid to the observation window 34 .

[0071] In addition, in the embodiment, Figure 2 and Figure 3 In the figure, the raised portion 62 is shown as an example of a structure in which the top 64 is located on the straight line G, but the structure of the raised portion 62 is not limited to this. For example, as long as the fluid ejected from the injection port 52 can be effectively branched to the pair of first guide surfaces 66 and 68, the top 64 may be offset in the direction of arrow H relative to the straight line G. However, as long as the raised portion 62 has the top 64 located on the straight line G, the fluid ejected from the injection port 52 can be evenly branched to the pair of first guide surfaces 66 and 68, which is preferred.

[0072] As a preferred embodiment, the fluid guide portion 60 of the embodiment further includes the following structure.

[0073] First, the fluid guide portion 60 includes a flat third guide surface 76 to facilitate smooth flow of the fluid passing through the second guide surface 70 toward the observation window 34. The third guide surface 76 is formed between the top portion 64 and the observation window 34. As an example, the third guide surface 76 is a surface perpendicular to the longitudinal axis A and is formed on the same plane as the surface 34S of the observation window 34 at a position closer to the front end in the longitudinal axis A direction than the front end surface 28.

[0074] By providing the third guide surface 76 in the fluid guide portion 60 , the fluid flowing from the second guide surface 70 toward the center portion 34C of the observation window 34 via the top portion 64 can be smoothly guided to the center portion 34C of the observation window 34 by the third guide surface 76 .

[0075] Furthermore, the fluid guide portion 60 has a guide shape that guides the fluid ejected from the ejection port 52 toward the entire area of the observation window 34. Specifically, the front view of the fluid guide portion 60, as viewed from the front in the direction of the longitudinal axis A, is formed into a trapezoidal shape that expands from the straight line G toward the direction of the arrow H as it moves from the fluid ejection nozzle 40 toward the observation window 34.

[0076] By forming the fluid guide portion 60 into the above-described guide shape, the fluid ejected from the ejection port 52 can be efficiently guided to the entire area of the observation window 34 .

[0077] Furthermore, the fluid guide portion 60 includes fourth guide surfaces 82 and 84 to guide the fluid ejected from the ejection port 52 that deviates from the pair of first guide surfaces 66 and 68 toward the two side portions 34A and 34B of the observation window 34 .

[0078] The fourth guide surfaces 82 and 84 are formed as inclined surfaces that include a component oblique to the longitudinal axis A and expand from the straight line G in the direction of arrow H as they approach the side portions 34A and 34B. Furthermore, the fourth guide surface 82 is formed to connect with the first guide surface 66 and face the side portions 34A, while the fourth guide surface 84 is formed to connect with the first guide surface 68 and face the side portions 34B. Furthermore, each of the fourth guide surfaces 82 and 84 is formed to have an arc shape along the outer circumference of the observation window 34 when viewed from the front in the direction of the longitudinal axis A.

[0079] By providing the fluid guide portion 60 with the fourth guide surfaces 82 and 84, the fluid ejected from the ejection port 52 that deviates from the pair of first guide surfaces 66 and 68 in the direction of arrow H is guided by the fourth guide surfaces 82 and 84 toward the side portions 34A and 34B of the observation window 34 as indicated by the third fluid paths 96 and 98 indicated by arrows M and N, and flows toward the side portions 34A and 34B. This allows the side portions 34A and 34B to be cleaned together with the fluid flowing along the first fluid paths 90 and 92 indicated by arrows J and K, thereby further improving the cleaning performance of the side portions 34A and 34B.

[0080] The above-mentioned fourth guide surfaces 82, 84 are formed by inclined surfaces including components oblique to the longitudinal axis A and extending from the straight line G in the direction of arrow H toward the two side portions 34A, 34B, so that the fluid deviating from a pair of guide surfaces 66, 68 in the direction of arrow H can be smoothly guided to the two side portions 34A, 34B.

[0081] In the embodiment, a pair of fourth guide surfaces 82 and 84 are exemplified as the fourth guide surface. However, the present invention is not limited thereto, and at least one of the pair of fourth guide surfaces 82 and 84 may be provided. However, providing a pair of fourth guide surfaces 82 and 84 is preferred because it enables cleaning of both side portions 34A and 34B of the observation window 34.

[0082] Furthermore, the maximum inclination angles of the pair of first guide surfaces 66, 68, the second guide surface 70, and the fourth guide surfaces 82, 84 of the fluid guide portion 60 relative to the front end surface 28 are set to preferred angles to enhance the cleaning power of the fluid. For example, the maximum inclination angles of the pair of first guide surfaces 66, 68, the second guide surface 70, and the fourth guide surfaces 82, 84 are set to effectively branch a portion of the fluid flowing on the second guide surface 70 toward the pair of first guide surfaces 66, 68, effectively guide the fluid flowing on the pair of first guide surfaces 66, 68 toward the two side portions 34A, 34B of the observation window 34, and effectively guide the fluid flowing on the fourth guide surfaces 82, 84 toward the two side portions 34A, 34B.

[0083] If we explain an example of the maximum tilt angle, Figure 6 In the illustration of the maximum inclination angle shown in the figure, when the maximum inclination angle of the second guide surface 70 is set to α, the maximum inclination angle of the pair of first guide surfaces 66 and 68 is set to β, and the maximum inclination angle of the fourth guide surfaces 82 and 84 is set to γ, each guide surface is constructed in a manner to form a relationship of a>β>γ.

[0084] Due to the aforementioned angular relationship, the second guide surface 70 is a steep surface, effectively branching a portion of the fluid flowing on the second guide surface 70 toward the pair of first guide surfaces 66, 68. Furthermore, the pair of first guide surfaces 66, 68 are flatter than the second guide surface 70, effectively guiding the fluid flowing on the pair of first guide surfaces 66, 68 toward the two side portions 34A, 34B of the observation window 34. Furthermore, the fourth guide surfaces 82, 84 are flatter than the first guide surfaces 66, 68, effectively guiding the fluid flowing on the fourth guide surfaces 82, 84 toward the two side portions 34A, 34B.

[0085] Furthermore, in order to further improve the cleaning power of the observation window 34, the fluid guide portion 60 adopts Figure 7 Here, in Figure 7 3 is a cross-sectional view of the main parts of the fluid ejecting nozzle 40 , the raised portion 62 , and the front end portion 22 of the observation window 34 as viewed from a direction perpendicular to the longitudinal axis A. FIG.

[0086] like Figure 7As shown, the positional relationship among the fluid ejecting nozzle 40 , the observation window 34 , and the ridge 62 is set so that the observation window 34 and the ridge 62 are included in a region extending the opening region of the ejection port 52 in the fluid ejecting direction.

[0087] To explain the positional relationship described above, the observation window 34 is arranged in the first extended region P, which is an extension of the distal end region of the opening region of the ejection port 52 in the direction of fluid ejection, on the distal side of the longitudinal axis A. Furthermore, the raised portion 62 is arranged in the second extended region Q, which is an extension of the proximal end region closer to the proximal end of the longitudinal axis A than the distal end region. Furthermore, the top portion 64 of the raised portion 62 is arranged between the first extended region P and the second extended region Q in the direction of the longitudinal axis A, so that the fluid flowing along the first extended region P does not collide with the top portion 64.

[0088] Due to the aforementioned positional relationship, the fluid injected along the first extended region P can be directly injected onto the observation window 34. Furthermore, the protrusions 62 are disposed on the second extended region Q, so that the fluid injected along the second extended region Q can flow through the protrusions 62 into the side portions 34A and 34B and the central portion 34C of the observation window 34. This allows the fluid to be effectively injected onto the entire observation window 34, further enhancing the cleaning efficiency of the observation window 34.

[0089] The configuration of each part of the fluid guide portion 60 has been described above. However, the endoscope 10 of the embodiment achieves a reduction in the diameter of the insertion portion 12, and thus also achieves miniaturization in the fluid ejection nozzle 40. Figure 5 As shown, when the observation window 34 is viewed from the front in the direction of the longitudinal axis A, an extended region R, which is formed by extending the opening region of the ejection port 52 in the fluid ejection direction, is formed on the observation window 34 at a position further inward than the outer periphery of the observation window 34. In the fluid ejection nozzle 40 having such a small ejection port 52, it is difficult to allow the fluid to flow directly through the two side portions 34A and 34B of the observation window 34. However, the endoscope 10 of the embodiment includes the fluid guide portion 60, and thus can effectively allow the fluid to flow through the two side portions 34A and 34B of the observation window 34.

[0090] And, as Figure 5 As shown, the injection port 52 preferably has an expansion portion 100 whose opening width expands in the direction of arrow H toward the observation window 34. This increases the flow momentum of the gas flowing along the third fluid paths 96 and 98, thereby further improving the cleaning power of the two side portions 34A and 34B.

[0091] As mentioned above, the endoscope according to the present invention has been described. However, the present invention is not limited to the above-mentioned examples, and some improvements or modifications may be made without departing from the gist of the present invention.

[0092] Explanation of symbols

[0093] 10-Endoscope, 12-Insertion portion, 14-Operation portion, 16-Universal cable, 18-Flexible portion, 20-Bending portion, 22-Front end portion, 24-Angle knob, 26-Angle knob, 28-Front end surface, 30-Front end portion body, 30A-Front end surface, 30B-Front end outer peripheral surface, 32-Front end cover, 34-Observation window, 34A-Both sides, 34B-Both sides, 34C-Center, 34S-Surface, 36-Optical system, 38-Lens barrel, 40-Fluid ejection nozzle, 40A-Base end portion, 40B-Front end portion, 41A-Pipeline, 41B-Pipeline, 42-Air and water supply channel, 42A-Front end portion, 44 -Illumination window, 44A-surface, 46-illumination window, 46S-surface, 48-treatment instrument outlet, 50-treatment instrument inlet, 52-injection port, 54-suction button, 56-air and water supply button, 60-fluid guide portion, 62-raised portion, 64-top, 66-first guide surface, 68-first guide surface, 70-second guide surface, 72-ridge portion, 74-ridge portion, 76-third guide surface, 82-fourth guide surface, 84-fourth guide surface, 90-first fluid path, 92-first fluid path, 94-second fluid path, 96-third fluid path, 98-third fluid path, 100-extension portion.

Claims

1. An endoscope comprising: An insertion portion having a distal end, a proximal end, and a longitudinal axis; an operating portion, disposed at the base end of the insertion portion; a front end surface, provided at the front end of the insertion portion; an observation window, disposed on the front end surface; a fluid ejection nozzle disposed on the front end surface and ejecting fluid from an ejection port opening toward the observation window; and a fluid guide portion, disposed between the fluid ejecting nozzle and the observation window, and guiding the fluid ejected from the ejection port toward the observation window; The fluid guide portion is provided on an extension of the opening area of the ejection port in the fluid ejection direction, and is composed of a raised portion raised from the front end side in the longitudinal direction of the front end surface. The raised portion has: a top portion formed at a front end side of the raised portion in the longitudinal direction; and A pair of first guide surfaces are formed on both sides of the top in a direction perpendicular to a straight line connecting the center of the injection port and the center of the observation window, and guide a portion of the fluid injected from the injection port to both sides of the observation window in the perpendicular direction.

2. The endoscope according to claim 1, wherein The pair of first guide surfaces are formed of inclined surfaces including a component oblique to the longitudinal axis and extending from the straight line toward the orthogonal direction as moving from the fluid ejecting nozzle toward the observation window.

3. The endoscope according to claim 1 or 2, wherein: The raised portion includes a second guide surface provided between the fluid ejecting nozzle and the top portion and guiding a portion of the fluid ejected from the ejection port toward the center of the observation window via the top portion.

4. The endoscope according to claim 3, wherein: The second guide surface is formed of an inclined surface that is inclined toward the front end side in the longitudinal axis direction as it moves from the fluid ejecting nozzle toward the observation window.

5. The endoscope according to claim 3, wherein: The pair of first guide surfaces and the second guide surface are connected to each other via a curved ridge portion.

6. The endoscope according to claim 3, wherein: The pair of first guide surfaces and the second guide surface each include a streamlined curved surface.

7. The endoscope according to claim 3, wherein: The fluid guide portion includes a flat third guide surface between the top portion and the observation window.

8. The endoscope according to claim 7, wherein: The front shape of the fluid guide portion when viewed from the front in the longitudinal direction is formed into a trapezoidal shape that expands from the straight line toward the orthogonal direction as it moves from the fluid ejecting nozzle toward the observation window.

9. The endoscope according to claim 3, wherein: The fluid guide portion has a fourth guide surface, which guides the fluid that deviates from the pair of first guide surfaces in the fluid ejected from the injection port to the two sides of the observation window, and is formed by an inclined surface that includes a component oblique to the longitudinal axis and expands from the straight line to the orthogonal direction as it moves toward the two sides.

10. The endoscope according to claim 9, wherein: When the maximum inclination angle of the second guide surface is set to α, the maximum inclination angle of the pair of first guide surfaces is set to β, and the maximum inclination angle of the fourth guide surface is set to γ, the respective maximum inclination angles of the pair of first guide surfaces, the second guide surface and the fourth guide surface relative to the front end surface are in the relationship of α>β>γ.

11. The endoscope according to claim 1 or 2, wherein: When the fluid injection nozzle, the raised portion and the observation window are observed from a direction perpendicular to the longitudinal axis, the observation window is arranged on a first extended area of the front end area on the front end side of the longitudinal axis in the opening area of the injection port extended in the fluid injection direction, and the raised portion is arranged on a second extended area of the base end area on the base end side of the longitudinal axis extended in the fluid injection direction relative to the front end area.

12. The endoscope according to claim 1 or 2, wherein: When the observation window is viewed from the front in the longitudinal direction, an extended region obtained by extending the opening region of the ejection port in the fluid ejection direction is formed on the observation window at an inner side than an outer periphery of the observation window.

13. The endoscope according to claim 12, wherein: The injection port has an expansion portion whose opening width expands in the orthogonal direction toward the observation window.

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