Endoscope

Abstract

To provide an endoscope that can control washing liquid from remaining at a surface of an observation optical system with a simpler configuration.SOLUTION: An endoscope includes: a convex observation optical system 132 which is installed to a tip of an insertion part and to which a gas / water supply nozzle 140 jets washing liquid; and an uneven-shaped tip surface 131 surrounding the observation optical system 132.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an endoscope having a convex observation optical system.

Background Art

[0002] Conventionally, in an endoscope, an observation optical system for imaging a subject is provided at the tip of an insertion portion inserted into the body. Liquid used for cleaning easily remains on the surface of such an observation optical system. Thus, when cleaning liquid remains on the observation optical system, it is difficult to capture a clear image of the subject.

[0003] In contrast, Patent Document 1 discloses an endoscope capable of suppressing the protrusion amount of an observation window from the tip of the insertion portion and improving the cleanability and drainage property of the observation window.

[0004] Patent Document 2 discloses an endoscope in which the window surface of the observation window protrudes from the flat portion of the tip cover by a predetermined height, an inclined portion is provided between the peripheral edge of the window surface of the observation window and the flat portion of the tip cover, and at least a part of the flat portion of the tip cover, the window surface of the observation window, and the inclined portion has a surface property with high affinity for cleaning liquid, thereby enhancing the performance of removing residual liquid remaining on the observation window.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] On the one hand, in order to improve the detection rate of lesions, widening the field of view of the observation optical system is required. Along with such widening of the field of view, the objective lens of the observation optical system has a convex shape and is increasing in diameter. Also, even in an observation optical system having such a convex shape, as described above, it is necessary to prevent the cleaning liquid from remaining on the surface of the observation optical system.

[0007] However, in the endoscope of Patent Document 1, the protrusion amount of the observation window is suppressed, and sufficient widening of the field of view of the observation optical system cannot be achieved. Further, in the endoscope of Patent Document 2, an inclined portion is provided between the peripheral edge of the window surface of the observation window and the flat portion of the tip cover, and since the surface characteristics of such an inclined portion are limited, the configuration is complicated.

[0008] The present invention has been made in view of such circumstances, and an object thereof is to provide an endoscope that can suppress the remaining of the cleaning liquid on the surface of the observation optical system with a simpler configuration in an endoscope provided with a convex observation optical system.

Means for Solving the Problems

[0009] The endoscope according to the present invention is an endoscope provided with a convex observation optical system provided at the tip of the insertion portion, from which a cleaning liquid is jetted from a nozzle, and includes an uneven tip surface surrounding the observation optical system. The endoscope according to the present invention is an endoscope provided with a convex observation optical system provided at the tip of the insertion portion, from which a cleaning liquid is jetted from a nozzle, and is characterized by including a tip surface that surrounds the observation optical system and is inclined in a frustum shape, and uneven portions formed on the tip surface.

[0010] In the present invention, since the tip surface surrounding the observation optical system has an uneven shape, the wettability of the tip surface is increased, and the remaining liquid after cleaning spreads and easily moves on the tip surface without gathering and stopping at the boundary between the observation optical system and the tip surface.

[0011] The manufacturing method of the endoscope according to the present invention is a manufacturing method of an endoscope provided with a convex observation optical system provided at the tip of the insertion portion and through which a cleaning liquid is jetted from a nozzle, and uneven processing is performed on the tip surface surrounding the observation optical system.

[0012] In the present invention, for example, by uneven processing such as blasting and etching, the tip surface has an uneven shape. Therefore, the wettability of the tip surface increases, and the residual liquid after cleaning spreads and moves easily on the tip surface without gathering and stopping at the boundary between the observation optical system and the tip surface.

[0013] The manufacturing method of the endoscope according to the present invention is a manufacturing method of an endoscope provided with a convex observation optical system provided at the tip of the insertion portion and through which a cleaning liquid is jetted from a nozzle, and an uneven tip surface surrounding the observation optical system is generated using a mold.

[0014] In the present invention, since the tip surface manufactured using a mold has an uneven shape, the wettability of the tip surface increases, and the residual liquid after cleaning spreads and moves easily on the tip surface without gathering and stopping at the boundary between the observation optical system and the tip surface.

Advantages of the Invention

[0015] According to the present invention, in an endoscope provided with a convex observation optical system, it is possible to prevent a cleaning liquid from remaining on the surface of the observation optical system with a simpler configuration.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

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Figure 8

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Figure 10

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Figure 12

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Figure 14

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Figure 16

Figure 17

Embodiments for Carrying Out the Invention

[0017] Hereinafter, the endoscope according to the embodiment of the present invention will be described in detail with reference to the drawings.

[0018] (Embodiment 1) FIG. 1 is an external view of the endoscope 10 according to Embodiment 1 of the present invention. The endoscope 10 according to the present embodiment includes an insertion portion 14, an operation portion 20, a universal cord 25, and a connector portion 24. The operation portion 20 has a button 201 and a bending knob 21 for receiving a user's operation, and a channel inlet 22 provided in a substantially cylindrical case 205. A forceps plug 23 having an insertion port for inserting a treatment instrument or the like is attached to the channel inlet 22.

[0019] The insertion portion 14 is inserted into the body of the subject. The insertion portion 14 is long and has a distal end portion 13, a bending portion 12, and a flexible portion 11 in order from one end of the distal end. The other end of the insertion portion 14 is connected to the operation portion 20 via a folding stop portion 16. The bending portion 12 bends in response to the operation of the bending knob 21.

[0020] In the following description, the longitudinal direction of the insertion portion 14 is also referred to as the insertion direction. Also, in the insertion portion 14, the other end side close to the operation portion 20 is referred to as the operation portion side, and the one end side close to the distal end portion 13 is also referred to as the distal end portion side.

[0021] The universal cord 25 is long, one end is connected to the operation portion 20, and the other end is connected to the connector portion 24, respectively. The universal cord 25 is flexible. The connector portion 24 is connected to an endoscope processor, a light source device, a display device, a gas supply and water supply device, etc. (not shown). By appropriately operating the operation portion 20, the cleaning fluid (air or water) sent through the connector portion 24 is sent to the distal end portion 13 via the folding stop portion 16.

[0022] FIG. 2 is an external view of the distal end portion 13 of the endoscope 10 according to Embodiment 1 of the present invention. FIG. 2A is a perspective view of the distal end portion 13, FIG. 2B is a view taken along the line B - B of FIG. 2A, and FIG. 2C is a view taken along the line C - C of FIG. 2A.

[0023] The distal end portion 13 has a substantially elliptical cross section and the distal end protrudes in a substantially conical shape. An observation optical system 132, an air supply and water supply nozzle 140, a channel outlet 18 (suction hole), etc. are provided on the distal end surface 131 of the distal end portion 13.

[0024] In addition, the distal end portion 13 has a cylindrical housing cylinder 19 in which an imaging element (not shown) or the like that captures the image light of the subject through the observation optical system 132 and performs imaging is housed, and the distal end surface 131 of the distal end portion 13 extends from the edge of the housing cylinder 19. Inside the housing cylinder 19, the curved portion 12, and the flexible portion 11, a passage for air and water injected through the air and water injection nozzle 140 is formed.

[0025] The observation optical system 132 is provided at the center of the distal end surface 131 of the distal end portion 13, and the objective lens is a circular convex lens. Also, on the distal end surface 131 of the distal end portion 13, an air and water injection nozzle 140 and a channel outlet 18 are provided around the observation optical system 132.

[0026] The distal end surface 131 of the distal end portion 13 surrounds the observation optical system 132 and has an appearance like a substantially frustum of a cone. That is, the distal end surface 131 is an inclined surface that extends from the edge of the observation optical system 132 in the tangential direction and is inclined with respect to the insertion direction. An air and water injection nozzle 140 is provided on such a distal end surface 131, and the channel outlet 18 is open.

[0027] The distal end surface 131 has an uneven shape. More specifically, a plurality of recesses 133 are randomly formed on the distal end surface 131. The interval between the recesses 133 is, for example, 0.1 to 0.35 mm, and the depth of the recesses 133 is, for example, 0.005 to 0.02 mm.

[0028] In the manufacturing process of the endoscope 10, for example, the distal end surface 131 is subjected to uneven processing. As a result, recesses 133 are formed on the distal end surface 131, and the distal end surface 131 becomes uneven as a whole. Examples of the uneven processing include blasting, etching, hairline finish, and the like.

[0029] FIG. 3 is a diagram showing the air and water injection nozzle 140 of the endoscope 10 according to Embodiment 1 of the present invention. FIG. 3A is a perspective view showing the appearance of the air and water injection nozzle 140, FIG. 3B is a cross-sectional view taken along line IIIB-IIIB of FIG. 2B, and FIG. 3C is a cross-sectional view taken along line IIIC-IIIC of FIG. 2B.

[0030] The air and water supply nozzle 140 injects air or liquid toward the observation optical system 132 along the tip surface 131. In the following, the case where the air and water supply nozzle 140 injects water will be described. The air and water supply nozzle 140 has a plurality of emission ports 141 through which water is emitted. The water is emitted toward the observation optical system 132 through each emission port 141. In the present embodiment, the case where the air and water supply nozzle 140 has two emission ports 141 will be described as an example. However, the present invention is not limited to this, and it may be configured to have three or more emission ports 141.

[0031] Each emission port 141 opens in a different direction from each other. That is, through each emission port 141, water is emitted in directions that do not cross each other. Each emission port 141 has an elliptical shape with the direction along the tip surface 131 as the major axis direction. Most of the air and water supply nozzle 140 (the dashed-dotted line portion in FIG. 3A) is inserted into and held by a hole formed in the tip surface 131.

[0032] As described above, the observation optical system 132 is provided at the tip of the distal end portion 13, and the tip surface 131 forms an inclined surface so as to surround the circular edge of the observation optical system 132, and the air and water supply nozzle 140 is provided on the tip surface 131 away from the observation optical system 132. That is, in the endoscope 10 according to the first embodiment of the present invention, in the longitudinal direction of the insertion portion 14 (refer to the arrow in FIG. 2C), the air and water supply nozzle 140 is disposed at a position closer to the other end of the insertion portion 14 (the operation portion 20 side) than the observation optical system 132.

[0033] In the observation optical system 132, since the objective lens is a convex lens and the viewing angle is wide (180 degrees or more), when the air and water supply nozzle 140 is arranged at the same position as the observation optical system 132 in the longitudinal direction of the insertion portion 14, the air and water supply nozzle 140 appears in the captured image of the observation optical system 132. However, in the endoscope 10 according to the first embodiment of the present invention, as described above, since the air and water supply nozzle 140 is arranged closer to the other end of the insertion portion 14 than the observation optical system 132, the air and water supply nozzle 140 does not appear in the captured image of the observation optical system 132 and does not interfere with the imaging by the observation optical system 132.

[0034] The air and water supply nozzle 140 has a cylindrical portion 147 and a lid portion 148 that seals one open end of the cylindrical portion 147. The lid portion 148 and the cylindrical portion 147 are integrally formed. The lid portion 148 is substantially disc-shaped and is inclined with respect to the longitudinal direction (axial direction) of the cylindrical portion 147.

[0035] In the air and water supply nozzle 140, an outlet 141 is formed at one end on the lid portion 148 side. The air and water supply nozzle 140 has a connecting pipe portion 142 that extends along the longitudinal direction of the cylindrical portion 147 inside the cylindrical portion 147. The connecting pipe portion 142 sends the water sent through the connector portion 24 and the folding stopper portion 16 to each outlet 141. That is, the water flowing into the connecting pipe portion 142 through the opening at one end of the connecting pipe portion 142 is sent to the outlet 141 on the other end side (lid portion 148 side).

[0036] A flow dividing portion 144 that divides the flow of water flowing through the connecting pipe portion 142 into the number of outlets 141 is provided at the other end on the downstream side (the end on the lid portion 148 side) of the connecting pipe portion 142. That is, the downstream side of the connecting pipe portion 142 is divided into two flow paths (flow dividing portions 144) having a smaller diameter than the connecting pipe portion 142. Each flow dividing portion 144 is provided so as to correspond to any one of the outlets 141, and the water flowing into each flow dividing portion 144 flows out through the corresponding outlet 141.

[0037] Also, on the downstream side of the connecting pipe portion 142 and upstream of the flow dividing portion 144, a reduced-diameter portion 143 having a funnel shape or a tapered shape is formed. That is, the reduced-diameter portion 143 is formed between the flow dividing portion 144 and the other end of the connecting pipe portion 142, and the diameter of the connecting pipe portion 142 is reduced at the reduced-diameter portion 143.

[0038] Therefore, the pressure of the water flowing into each flow dividing portion 144 through the reduced-diameter portion 143 is reduced, and the flow velocity becomes faster. The water with an increased flow velocity flows out into a space wider than the flow dividing portion 144 (see FIGS. 3B and 3C), and flows toward the outlet 141. At this time, the water forms vortices having vectors in various directions, and then is ejected from the outlet 141. Thus, the water ejected from each outlet 141 spreads over a wide range, and the ejection force and range at the time of ejection can be ensured. In FIG. 3C, the flow path of the water is indicated by a broken line.

[0039] As described above, in the air and water supply nozzle 140, the directions of the respective outlets 141 are different from each other, and the water ejected from each outlet 141 travels in directions that do not cross each other. That is, the outlets 141 are provided so that if the water is ejected linearly through the outlets 141 and maintains a linear shape even after ejection, the water from each outlet 141 does not cross each other.

[0040] Due to having such a configuration, the endoscope 10 according to the present embodiment can be cleaned neatly from the portion of the air and water supply nozzle 140 side where the ejected water directly hits in the observation optical system 132 having a convex shape to the side opposite to such a portion even with a single air and water supply nozzle 140. Hereinafter, in the observation optical system 132, the portion of the air and water supply nozzle 140 side where the ejected water directly hits is referred to as the nozzle side portion, and the side opposite to such a nozzle side portion is referred to as the nozzle opposite portion.

[0041] Generally, a fluid flowing near a wall surface is attracted to the wall surface by the effect of fluid viscosity (referred to as the Coanda effect). Due to such a Coanda effect, when a fluid is made to flow along the surface (curved surface) of a convex lens, such a fluid exhibits a behavior of concentrating toward the center of the curved surface. The fluid concentrated in this way detaches from the curved surface of the convex lens due to its weight and inertia. Therefore, when water is sprayed onto the nozzle side portion of the observation optical system using a single air and water supply nozzle (outlet), the water does not flow to the opposite side of the nozzle of the observation optical system, resulting in insufficient cleaning of the observation optical system.

[0042] Even if the outlet of the air and water supply nozzle is widened and water is sprayed over a wide range of the observation optical system, the water emitted from the outlet invariably concentrates toward the center of the observation optical system, and as described above, detachment from the curved surface of the observation optical system occurs.

[0043] Also, even when the air and water supply nozzle has a plurality of outlets and water is sprayed from the plurality of outlets, the water from one outlet begins to spread after emission and merges with the water from other outlets. Therefore, as described above, it concentrates toward the center of the observation optical system and detaches from the curved surface of the observation optical system.

[0044] In contrast, the endoscope 10 according to Embodiment 1 of the present invention is provided with each outlet 141 with different orientations of the two outlets 141 so that the emitted water does not cross each other. Therefore, it is possible to suppress the water emitted from one outlet 141 from merging with the water emitted from the other outlet 141. Thus, it is possible to prevent water from concentrating toward the center of the observation optical system 132 and detaching from the curved surface of the observation optical system 132, and the water can flow to the opposite side of the nozzle in the observation optical system 132 for cleaning. Also, since the water from each outlet 141 comes toward the center of the observation optical system 132 due to the Coanda effect, the entire observation optical system 132, including the central portion of the observation optical system 132, can be sufficiently cleaned.

[0045] Figures 4 and 5 show the results of simulating the flow path of the water jetted by the air and water nozzle 140 in the endoscope 10 according to Embodiment 1 of the present invention. Figure 4 mainly shows the upstream side of the flow path, and Figure 5 mainly shows the downstream side. That is, Figure 5 shows the flow path at the portion of the observation optical system 132 opposite to the nozzle. In Figure 4, the two-dot chain line indicates the direction of each outlet 141, and the solid line indicates the flow path of the water emitted from the outlet 141. For convenience, in Figures 4 and 5, the illustration of the uneven shape of the tip surface 131 is omitted.

[0046] As can be seen from Figures 4 and 5, in the endoscope 10 according to Embodiment 1 of the present invention, although the water emitted from one outlet 141 begins to spread immediately after emission (see the arrow in Figure 4), there is almost no confluence with the water emitted from the other outlets 141, no concentration at the center of the observation optical system 132 is found, and no detachment from the curved surface of the observation optical system 132 has occurred. Also, the water jetted from the air and water nozzle 140 flows up to the portion of the observation optical system 132 opposite to the nozzle (see Figure 5). Therefore, the entire observation optical system 132 can be sufficiently cleaned.

[0047] On the other hand, the observation optical system 132 is made of glass, and the tip surface 131 is made of resin. Generally, since the contact angle of glass with respect to a liquid (water) is about half of the contact angle with resin, the wettability (hydrophilicity) of the observation optical system 132 is better than the wettability of the tip surface 131. That is, water spreads more easily and moves more easily on the observation optical system 132 than on the tip surface 131. Further, in the observation optical system 132, the objective lens is a convex lens and has a curved surface, so the wettability with water droplets increases.

[0048] Figure 6 is a comparison diagram comparing the contact angle when a water droplet adheres to a flat surface and the contact angle when a water droplet adheres to a curved surface. Figure 6A shows the case where a water droplet adheres to a flat surface, and Figure 6B shows the case where a water droplet adheres to a curved surface.

[0049] As can be seen from FIG. 6, the contact angle θ2 when water droplets adhere to the curved surface is smaller than the contact angle θ1 when water droplets adhere to the flat surface, indicating an increase in wettability. Therefore, on the observation optical system 132, the water droplets are more likely to spread and move.

[0050] However, as described above, the contact angle of water with the resin is about twice as large as that with glass, resulting in poor wettability, so the mobility of water in the resin is inferior. Therefore, after the water injection from the air and water supply nozzle 140 ends, the residual water (residual liquid) remaining on the observation optical system 132 may move on the surface of the observation optical system 132 and gather and stop at the boundary between the observation optical system 132 and the tip surface 131. In such a case, it hinders the imaging of the subject and makes it difficult to capture a clear image.

[0051] On the other hand, in the endoscope 10 according to the first embodiment, as described above, the tip surface 131 has an uneven shape, which can suppress the remaining of water droplets at the boundary between the observation optical system 132 and the tip surface 131. This will be described in detail below.

[0052] FIG. 7 is an explanatory diagram showing the flow of residual water on the observation optical system 132 and the tip surface 131 after the water injection by the air and water supply nozzle 140 in the endoscope 10 according to the first embodiment of the present invention. FIGS. 7A, 7B, and 7C show the flow of residual water over time. In FIGS. 7A, 7B, and 7C, the thick solid circles indicate the residual water.

[0053] As described above, the wettability between water droplets and the resin is worse than that between water droplets and glass. On the tip surface 131 made of resin, the water droplets may be difficult to spread and move. However, in the endoscope 10 according to the first embodiment of the present invention, since the tip surface 131 has an uneven shape, the contact area between the tip surface 131 and the water droplets has increased, thereby increasing the hydrophilicity. Therefore, the droplets are likely to spread and move on the tip surface 131.

[0054] Specifically, after the water injection from the air and water nozzle 140 ends, as shown in FIG. 7A, the residual water remaining in the central portion of the tip surface 131 including the observation optical system 132 begins to flow in the direction of gravity (the direction of the arrow in FIG. 7A). At this time, the residual water forms an aggregate as a whole due to surface tension.

[0055] While maintaining the aggregated state by surface tension, the residual water moves on the surface of the observation optical system 132 to the boundary between the observation optical system 132 and the tip surface 131, that is, to the edge of the tip surface 131. The hydrophilicity of the tip surface 131 is enhanced by the uneven shape, and the residual water reaching the edge of the tip surface 131 spreads and moves onto the tip surface 131 without staying (see FIGS. 7B and 7C). In this way, the residual water moves to the edge of the tip surface 131 and flows down.

[0056] That is, after the water injection from the air and water nozzle 140 ends, the residual water remaining in the central portion of the tip surface 131 including the observation optical system 132 begins to move while maintaining the state of an aggregate, and moves from the observation optical system 132 to the tip surface 131 without staying at the boundary between the observation optical system 132 and the tip surface 131. Therefore, it is difficult for water droplets to remain on the observation optical system 132.

[0057] As described above, the endoscope 10 according to Embodiment 1 can prevent the cleaning water from remaining on the surface of the observation optical system 132 after the injection of the cleaning water, with a simple configuration in which the tip surface 131 has an uneven shape.

[0058] In the above description, the case where only the tip surface 131 has an uneven shape has been described, but it is not limited thereto. For example, in addition to the tip surface 131, the housing cylinder 19 (surface) may also be configured to have an uneven shape.

[0059] In the above description, the case where the distal end surface 131 has a substantially frustum - shaped and is inclined with respect to the longitudinal direction of the insertion portion 14 has been described as an example, but it is not limited thereto. FIG. 8 is an exemplary view showing a modified example of the distal end surface 131 in the endoscope 10 according to Embodiment 1 of the present invention, and FIG. 9 is a cross - sectional view taken along line IX - IX in FIG. 8. Hereinafter, the modified example of the distal end surface 131 will be referred to as the distal end surface 131A.

[0060] The distal end surface 131A is a flat surface orthogonal to the longitudinal direction of the insertion portion 14 and has an uneven shape. Further, an observation optical system 132, an air - and - water supply nozzle 140, and a channel outlet 18 are provided on the distal end surface 131A. As shown in FIGS. 8 and 9, even when the distal end surface 131A is a flat surface, it goes without saying that the above - described effects are achieved.

[0061] (Embodiment 2) FIG. 10 is a view showing the distal end surface 131B of the endoscope 10 according to Embodiment 2 of the present invention, and FIG. 11 is an enlarged cross - sectional view taken along line XI - XI in FIG. 10.

[0062] At the center of the distal end surface 131B, an observation optical system 132 is provided in the same manner as in Embodiment 1. That is, the distal end surface 131B surrounds the observation optical system 132. The distal end surface 131B is an inclined surface that extends in the tangential direction from the edge of the observation optical system 132 and is inclined with respect to the insertion direction, and has a substantially frustum - shaped. An air - and - water supply nozzle 140 is provided on the distal end surface 131B, and the channel outlet 18 is open.

[0063] The distal end surface 131B has an uneven shape. More specifically, a plurality of convex portions 134 are formed at equal intervals on the distal end surface 131B. Each convex portion 134 extends linearly in a direction away from the proximal side of the observation optical system 132. That is, the plurality of convex portions 134 are formed radially around the observation optical system 132.

[0064] In the manufacturing process of the endoscope 10, the tip surface 131B is formed using, for example, a mold. The interval between the convex portions 134 is, for example, 0.3 to 0.5 mm, the height of the convex portion 134 is, for example, 0.1 mm, and the width of the convex portion 134 is, for example, 0.3 mm. In this way, a plurality of convex portions 134 are formed on the tip surface 131B, and the tip surface 131B becomes uneven as a whole. Also, since it becomes relatively concave between the convex portions 134, a groove 134A is formed (see FIG. 11).

[0065] In the above, the case where a plurality of convex portions 134 are formed on the tip surface 131B and these constitute the groove 134A has been described, but the present invention is not limited to this. A concave portion having the same shape as the convex portion 134 may be formed on the tip surface 131B.

[0066] Also in the endoscope 10 according to the second embodiment, since the tip surface 131B has an uneven shape, the contact area between the tip surface 131B and the residual water has increased, and the hydrophilicity has become high. Therefore, on the tip surface 131B, the residual water is likely to spread and move easily.

[0067] Therefore, after the water injection from the air and water supply nozzle 140 ends, the residual water remaining in the central portion of the tip surface 131B including the observation optical system 132 moves while maintaining the state of a single aggregate, and does not stop at the boundary between the observation optical system 132 and the tip surface 131B, but moves to the tip surface 131B. Thus, it is difficult for water droplets to remain on the observation optical system 132.

[0068] Furthermore, in the endoscope 10 according to the second embodiment, adjacent convex portions 134 extend in the same direction to form the groove 134A. Thereby, the movement of the residual water is induced. Therefore, it is possible to prevent the movement of the residual water on the tip surface 131B from being unnecessarily delayed.

[0069] On the one hand, a user of the endoscope 10 can suck the residual water on the distal end face 131B through the channel outlet 18 by appropriately operating the button 201 (see FIG. 1). On the other hand, in the endoscope 10 according to the second embodiment, as described above, the plurality of convex portions 134 or grooves 134A extend radially around the observation optical system 132, and a part thereof extends from the observation optical system 132 to the channel outlet 18. Therefore, the convex portion 134 or the groove 134A can guide the residual water on the distal end face 131B (observation optical system 132) to the channel outlet 18, and the suction of the residual water from the channel outlet 18 can be performed more efficiently.

[0070] The convex portion 134 protruding from the distal end face 131B may have a constant dimension (width) in a direction intersecting the protruding direction, or may be configured such that the width becomes narrower as it approaches the tip. When the width is made narrower as it approaches the tip, it becomes easier to remove from the mold during manufacturing using the mold.

[0071] For parts similar to those in the first embodiment, the same reference numerals are given and detailed description is omitted.

[0072] (Embodiment 3) FIG. 12 is a view showing the distal end face 131C of the endoscope 10 according to the third embodiment of the present invention, and FIG. 13 is an enlarged cross-sectional view taken along line XIII-XIII in FIG. 12.

[0073] The distal end face 131C surrounds the observation optical system 132 provided at the center, and is an inclined surface that extends in the tangential direction from the edge of the observation optical system 132 and is inclined with respect to the insertion direction, and has a substantially frustum shape. A gas supply / water supply nozzle 140 is provided on the distal end face 131C, and the channel outlet 18 is open.

[0074] The distal end face 131C has an uneven shape. More specifically, a plurality of convex portions 135 are formed on the distal end face 131C at substantially equal intervals. Each convex portion 135 extends linearly or curvilinearly in a direction away from the proximal side of the observation optical system 132. The plurality of convex portions 135 include a linear convex portion 135A or a curvilinear convex portion 135B that extends from the observation optical system 132 to the channel outlet 18. The convex portion 135B is arranged in parallel in a direction orthogonal to the convex portion 135A, and the length and curvature increase as the distance from the convex portion 135A increases.

[0075] In the manufacturing process of the endoscope 10, the distal end face 131C is formed using, for example, a mold. As a result, a plurality of convex portions 135 are formed on the distal end face 131C, and the distal end face 131C becomes uneven as a whole. Also, since a relatively concave portion is formed between the convex portions 135, a groove 135C is formed. In other words, a groove 135C that extends from the observation optical system 132 to the channel outlet 18 is formed on the distal end face 131C (see FIG. 12).

[0076] In the above, the case where a plurality of convex portions 135 are formed on the distal end face 131C and these constitute the groove 135C has been described, but it is not limited thereto. A concave portion having the same shape as the convex portion 135 may be formed on the distal end face 131C.

[0077] Also in the endoscope 10 according to the third embodiment, since the distal end face 131C has an uneven shape, the contact area between the distal end face 131C and the residual water has increased, and the hydrophilicity has become high. Therefore, on the distal end face 131C, the residual water easily spreads and moves.

[0078] Therefore, after the water injection from the air and water supply nozzle 140 ends, the residual water remaining in the central portion of the distal end face 131C including the observation optical system 132 moves while maintaining the state of a single aggregate, and does not stop at the boundary between the observation optical system 132 and the distal end face 131C, but moves to the distal end face 131C. Thus, it is difficult for water droplets to remain on the observation optical system 132.

[0079] Furthermore, in the endoscope 10 according to the third embodiment, adjacent convex portions 135 extend while forming a groove 135C therebetween, thereby inducing the movement of residual water. Therefore, it is possible to prevent the movement of residual water on the distal end surface 131C from being unnecessarily slowed down.

[0080] On the other hand, the user of the endoscope 10 can suck the residual water on the distal end surface 131C through the channel outlet 18 by appropriately operating the button 201 (see FIG. 1). In contrast, in the endoscope 10 according to the third embodiment, as described above, the linear convex portion 135A or the curved convex portion 135B (groove 135C) is configured to extend from the observation optical system 132 to the channel outlet 18. Therefore, the convex portions 135A and 135B (groove 135C) can guide the residual water on the distal end surface 131C (observation optical system 132) to the channel outlet 18, and the suction of the residual water from the channel outlet 18 is performed more efficiently.

[0081] For the parts similar to those of the first embodiment, the same reference numerals are given and the detailed description is omitted.

[0082] (Fourth Embodiment) FIG. 14 is a view showing the distal end surface 131D of the endoscope 10 according to the fourth embodiment of the present invention, and FIG. 15 is an enlarged cross-sectional view taken along line XV-XV of FIG. 14. The distal end surface 131D is provided with an observation optical system 132 at the center, and is an inclined surface that extends from the edge of the observation optical system 132 in the tangential direction and is inclined with respect to the insertion direction, and has a substantially frustum shape. A gas supply / water supply nozzle 140 is provided on the distal end surface 131D, and the channel outlet 18 is open.

[0083] The distal end surface 131D has an uneven shape. More specifically, a plurality of convex portions 136 are formed on the distal end surface 131D. Each convex portion 136 has a dot shape.

[0084] In the manufacturing process of the endoscope 10, the distal end surface 131D is formed using, for example, a mold. As a result, a plurality of convex portions 136 are formed on the distal end surface 131D, and the distal end surface 131D becomes uneven as a whole. Also, it is not limited to this. A concave portion having the same shape as the convex portion 136 may be formed on the distal end surface 131D.

[0085] Also in the endoscope 10 according to the fourth embodiment, since the distal end surface 131D has an uneven shape, the contact area between the distal end surface 131D and the residual water has increased. Therefore, the hydrophilicity is enhanced, and on the distal end surface 131D, the residual water is likely to spread and move easily.

[0086] Therefore, after the water injection from the air and water supply nozzle 140 ends, the residual water remaining in the central portion of the distal end surface 131D including the observation optical system 132 does not stop at the boundary between the observation optical system 132 and the distal end surface 131D, but moves to the distal end surface 131D while maintaining the state of a single aggregate. Thus, it is difficult for water droplets to remain on the observation optical system 132.

[0087] In the above, the case where the observation optical system 132 is made of glass and the distal end surfaces 131, 131A, 131B, 131C, 131D (hereinafter simply referred to as the distal end surface 131) are made of resin has been described as an example, but the present invention is not limited to this. For example, the observation optical system 132 may be configured to be made of resin. Even in such a case, it goes without saying that the above-described effects can be achieved.

[0088] That is, when the observation optical system 132 and the distal end surface 131 are made of resin, since the distal end surface 131 has an uneven shape, the wettability of the distal end surface 131 becomes better than the wettability of the observation optical system 132. Therefore, the residual water does not stop at the boundary between the observation optical system 132 and the distal end surface 131C, but moves to the distal end surface 131C. Thus, it is difficult for water droplets to remain on the observation optical system 132.

[0089] (Embodiment 5) FIG. 16 is an external view showing the distal end portion 13 of the endoscope 10 according to the fifth embodiment of the present invention, and FIG. 17 is a cross-sectional view taken along line XVII-XVII of FIG. 16.

[0090] Inside the accommodation cylinder 19 of the distal end portion 13, an annular light distribution lens 137 is fitted. In the light distribution lens 137, one end portion on the distal end side of the distal end portion 13 is curved inward and the diameter is reduced, and a diameter-reduced portion is formed. As a result, the outer surface of the one end portion of the light distribution lens 137 forms an inclined surface with respect to the axis of the accommodation cylinder 19. That is, in the endoscope 10 according to the fifth embodiment of the present invention, the outer surface of one end portion of the light distribution lens 137 forms the distal end surface 131 of the distal end portion 13.

[0091] An observation optical system 132 is provided on the central side of the light distribution lens 137. The observation optical system 132 includes an observation window 61 and a plurality of lenses 60. The observation window 61 is a wide-angle objective lens having a substantially hemispherical shape. The plurality of lenses 60 includes lenses not shown together with the lens 60A and the lens 60B. By setting the observation optical system 132 including the observation window 61 and the plurality of lenses 60, imaging with a field angle of 180° or more is possible.

[0092] Also, on the central side of the light distribution lens 137, a lens holding cylinder 138 for holding the observation window 61 and the plurality of lenses 60 is provided. The lens holding cylinder 138 has a cylindrical shape extending along the axis of the light distribution lens 137. One end side of the lens holding cylinder 138 has an enlarged diameter, and the end surface of the one end side is exposed from the distal end surface 131 and is surrounded by the edge of one end portion of the light distribution lens 137.

[0093] The observation window 61 and the plurality of lenses 60 are arranged on the axis of the lens holding cylinder 138. The observation window 61 is fitted in the enlarged diameter portion of the lens holding cylinder 138, and the peripheral portions of the plurality of lenses 60 are sandwiched between the inner surfaces of the lens holding cylinder 138 inside the observation window 61 so as to be adjacent to each other. The observation window 61 is exposed to the outside from the distal end surface 131. The exposed portion of the observation window 61 is surrounded by the lens holding cylinder 138 and is continuous with one end of the lens holding cylinder 138.

[0094] Inside the housing cylinder 19, the lighting unit 70 is incorporated between the lens holding cylinder 138 and the light distribution lens 137. That is, the lighting unit 70 is provided around the outer peripheral surface of the lens holding cylinder 138. The lighting unit 70 includes a cylindrical lighting holding portion 73 that surrounds the lens holding cylinder 138, an annular substrate 71 provided on the end surface of the lighting holding portion 73, and a plurality of LEDs 72 mounted on one surface of the substrate 71 facing the light distribution lens 137.

[0095] The LEDs 72 are arranged at substantially equal intervals in the circumferential direction of the substrate 71. The light emitted by the LEDs 72 is emitted through the light distribution lens 137 to illuminate the imaging field of the observation optical system 132. The LEDs 72 are, for example, white LEDs that emit white light. Also, the LEDs 72 may be other light emitting elements such as LDs.

[0096] The dashed line in Fig. 17 indicates the light distribution range of the LEDs 72. The light emitted by the LEDs 72 enters a wide range of the reduced diameter portion and the curved portion at one end of the light distribution lens 137 and spreads greatly. Note that at one end of the light distribution lens 137, a concave portion is formed on the inner surface of the curved portion. Due to the action of this concave portion, the light distribution of the LEDs 72 is irradiated over a wide range.

[0097] Furthermore, in the endoscope 10 according to Embodiment 5 as well, the distal end surface 131 has an uneven shape. Therefore, the light emitted by the LEDs 72 enters the light distribution lens 137 and is diffused and emitted at the distal end surface 131.

[0098] Therefore, in the endoscope 10 according to Embodiment 5, the light emitted by the LEDs 72 is distributed over the entire imaging field of the observation optical system 132. That is, the light distribution angle of the lighting unit 70 is equal to or greater than the viewing angle of the observation optical system 132. Thus, with the endoscope 10 according to Embodiment 5, imaging can be performed with sufficient light quantity over the entire field of view of the observation optical system 132.

Explanation of Reference Numerals

[0099] 10 Endoscope 14 Insertion portion 13 Tip portion 18 Channel outlet The front end faces of 131, 131A, 131B, 131C, and 131D 132 Observation optical system 133 Concave portion 134, 135, and 136 Convex portions 140 Air and water supply nozzle 141 Outlet

Claims

1. An endoscope provided with a convex observation optical system provided at the tip of an insertion portion, from which a cleaning liquid is sprayed from a nozzle, surrounding the observation optical system, having an inclined tip surface, concavo-convex portions formed on the tip surface, a housing cylinder that is continuous with the tip surface and houses an imaging element that performs imaging through the observation optical system, and a lighting unit provided inside the housing cylinder and surrounding the observation optical system, wherein the lighting unit comprises an annular substrate surrounding the observation optical system, and a plurality of light-emitting elements mounted on a mounting surface of the substrate facing the tip surface. An endoscope.

2. Comprising a light distribution lens for spreading the light from the lighting unit, The endoscope according to claim 1, wherein the tip surface is composed of the light distribution lens.

3. The light distribution lens has a concave portion formed on the inner surface facing the lighting unit to widen the irradiation range of the light of the lighting unit. The endoscope according to claim 2.

Images