JP2015027324A - Endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endoscope capable of always capturing a clear image by reliably removing a cleaning fluid remaining at the small-diameter tip of the endoscope when washing the tip, with an extremely simple constitution.SOLUTION: The endoscope comprising an insertion part to be inserted to the inside of an observation target comprises: a tip face 40 which is configured at the tip of the insertion part and includes a transparent optical area for guiding light to an image sensor 17; and a water pouring part 38 which discharges the cleaning fluid for washing a range equivalent to at least the optical area of the tip face 40. A water repellent coat is applied to the range of the optical area, and a hydrophilic coat area 52 is provided at a part facing the water pouring part 38 across the optical area, on the tip face 40.

Description

  The present invention relates to an endoscope that images the inside of an observation target that cannot be directly observed from the outside.

  2. Description of the Related Art Conventionally, endoscopes for imaging a patient's body and the inside of devices and structures are widely used in the medical field and the industrial field. As an endoscope of this type, at the insertion part inserted inside the observation object, the light from the imaging part is imaged on the light receiving surface of the image sensor by the objective lens system, and the imaged light is converted into an electrical signal. A configuration is known in which a video signal is transmitted to an external image processing apparatus or the like via a signal cable.

  Especially in endoscopes inserted into the body, if a body fluid such as blood adheres to the tip that captures light from the imaging site, the optical path to the image sensor is blocked and a clear image cannot be captured. It is necessary to clean the tip.

  As an endoscope provided with such a cleaning mechanism, for example, a wiper for wiping an observation window provided on the distal end surface of the endoscope insertion portion, air emitted to the distal end surface of the endoscope insertion portion, and a cleaning liquid An exit groove that guides the mixed water, and normally the wiper is made to wait outside the field of view of the observation window by the biasing force of the tension spring, and when the mixed water is applied to the wiper via the exit groove, the tension spring and the mixed water are A technique for wiping the observation window by moving the wiper in balance with the emission pressure is disclosed (Patent Document 1).

  Also, it has a water supply nozzle for spraying water on a cover lens provided with a water repellent coating provided at the tip of the endoscope, and a hydrophilic portion having hydrophilicity is provided at a position overlapping with the water flow path flowing out from the water supply nozzle A technique is disclosed (Patent Document 2).

  In addition, a hood surrounding them is provided at the distal end of the flexible tube having the observation window, the air / water supply nozzle, and the suction port, and water is supplied to the hood in front of the opening end of the air / water supply nozzle. There is disclosed a technique in which an ear piece to be changed is provided, and an introduction small piece extending from the surface periphery of the observation window to reach the periphery of the suction port is further provided on the surface of the tip (Patent Document 3).

  In addition, a technique of applying a water-repellent coating to the surfaces of an objective lens and an illumination window lens provided at a position facing the air / water supply nozzle at the distal end of the endoscope is disclosed (Patent Document 4).

JP 2008-279202 A JP 07-31442 A Japanese Utility Model Publication No.59-022101 Japanese Patent Laid-Open No. 02-129613

  By the way, in the endoscopes as described above, insertion portions having various outer diameters (for example, about 5 mm to 15 mm) are employed depending on applications, but in recent years, insertion portions for the purpose of reducing the burden on patients, In particular, the diameter of the tip is being reduced. When the diameter of the tip portion is reduced to 2 mm or less, the surface tension of the cleaning liquid becomes dominant on the tip surface constituting the tip portion, and a phenomenon occurs in which the injected cleaning liquid remains as hemispherical water droplets at the tip portion. This phenomenon occurs even when a water repellent coat, hydrophilic coat, super water repellent coat, etc. are applied to the entire tip surface. Furthermore, the outer edge of the tip surface is simply chamfered, or a groove that allows water droplets to escape to the side surface of the tip portion. Even if formed, it is difficult to solve. That is, the outer edge of the thinned tip surface substantially constitutes an edge, and water droplets formed by the cleaning liquid are fixed to the edge portion by a so-called “wetting pinning effect”. In this case, even if air is supplied to the tip surface, it is difficult to completely remove the remaining water droplets. If water droplets remain at the tip, this becomes a lens that distorts the normal optical path, resulting in an unclear image.

  However, in the technique disclosed in Patent Document 1, mechanical elements such as a wiper and a biasing member are required to remove the cleaning liquid remaining at the distal end portion of the endoscope, and the structure is complicated. In the technique disclosed in Patent Document 2, the hydrophilic portion provided at the outer edge of the cover lens is provided for the purpose of diffusing the cleaning liquid flowing out from the water supply nozzle in the direction of the cover lens. Eventually, the cleaning liquid adhering to the cover lens is removed by blowing gas from the air supply nozzle, which also complicates the configuration. Further, in Patent Document 3, the cleaning liquid is guided to the suction port by the capillary phenomenon in which the introduction piece appears, but providing the suction port itself makes the structure complicated. As described above, the techniques disclosed in Patent Documents 1 to 3 have a complicated configuration in order to remove the cleaning liquid remaining at the distal end portion of the endoscope, and it is difficult to reduce the diameter itself. ing.

  Further, even if the objective lens is provided with a water-repellent coating as disclosed in Patent Document 4, if the endoscope is thinned, the cleaning liquid remains on the objective lens due to the “wetting pinning effect”. Cannot shoot clear images.

  The present invention has been devised to solve such problems of the prior art, and its main purpose is to reduce the diameter when cleaning the distal end portion of the endoscope with an extremely simple configuration. It is an object of the present invention to provide an endoscope that can reliably remove a cleaning liquid from a tip portion that has been made and can always capture a clear image.

  The present invention is an endoscope provided with an insertion portion to be inserted inside an observation object, and includes a distal end surface including a transparent optical region configured at the distal end of the insertion portion and guiding light to an image sensor; A water injection part that discharges a cleaning liquid that cleans at least the area corresponding to the optical region of the tip surface, and a water repellent coat is applied to the range of the optical region, and the water injection is sandwiched between the optical region on the tip surface A hydrophilic coat region is provided in a portion facing the part.

  According to the present invention, when cleaning the distal end portion of the endoscope with an extremely simple configuration, it is possible to reliably remove the cleaning liquid from the diameter-reduced distal end portion and always capture a clear image. Become.

1 is an overall configuration diagram of an endoscope system using an endoscope according to a first embodiment of the present invention. Exploded perspective view showing the configuration of the distal end portion of the endoscope Lower perspective view showing the configuration of the distal end portion of the endoscope Upper perspective view showing the configuration of the distal end portion of the endoscope (A)-(e) is explanatory drawing which shows the form change of the washing | cleaning liquid at the time of pouring washing | cleaning liquid with respect to the front end surface of a flange part. The upper perspective view which shows the front-end | tip part of the endoscope which concerns on 2nd Embodiment of this invention. The upper perspective view which shows the front-end | tip part of the endoscope which concerns on 3rd Embodiment of this invention. (A) is a front view of the front-end | tip part of the endoscope which concerns on 4th Embodiment of this invention, (b) is principal part sectional drawing of the front-end | tip part of the endoscope which concerns on 4th Embodiment of this invention. (A)-(c) is explanatory drawing explaining the process in which washing | cleaning liquid is discharged | emitted from the front end surface of the endoscope which concerns on 4th Embodiment of this invention. (A) is a principal part perspective view of the front-end | tip part of the endoscope which concerns on 5th Embodiment of this invention, (b) is principal part cross section of the front-end | tip part of the endoscope which concerns on 5th Embodiment of this invention. Figure (A)-(c) is explanatory drawing explaining the process in which washing | cleaning liquid is discharged | emitted from the front end surface of the endoscope which concerns on 5th Embodiment of this invention. (A) is a front view of the front-end | tip part of the endoscope which concerns on 6th Embodiment of this invention, (b) is principal part sectional drawing of the front-end | tip part of the endoscope which concerns on 6th Embodiment of this invention. (A)-(c) is explanatory drawing explaining the process in which washing | cleaning liquid is discharged | emitted from the front end surface of the endoscope which concerns on 6th Embodiment of this invention.

  The present invention made to solve the above-mentioned problems is an endoscope provided with an insertion portion to be inserted into an observation target, and is configured to be transparent at the tip of the insertion portion to guide light to an image sensor. A distal end surface including an optical region, and a water injection part that discharges a cleaning liquid that cleans at least the region corresponding to the optical region of the distal surface, and a water-repellent coating is applied to the optical region range, A hydrophilic coat region is provided at a portion facing the water injection portion with the optical region interposed therebetween.

  Accordingly, when the distal end surface of the endoscope is cleaned with an extremely simple configuration, it is possible to reliably remove the cleaning liquid from the reduced distal end surface and always capture a clear image.

  Further, the present invention is an endoscope provided with an insertion portion to be inserted inside an observation object, and surrounds at least a part of the optical member and a transparent optical member that guides light to an image sensor. And an optical member holder that forms a distal end surface at the distal end of the insertion portion together with the optical member, and a water injection portion that is provided on the optical member holder and discharges a cleaning liquid that cleans the outer surface of the optical member at the distal end surface And a water repellent coat is applied to the outer surface of the optical member, and the optical member holder includes a hydrophilic coat region at a portion facing the water injection portion with the optical member interposed therebetween.

  Accordingly, when cleaning the distal end portion of the endoscope with an extremely simple configuration, it becomes possible to reliably remove the cleaning liquid from the thinned distal end portion and always capture a clear image.

  In the present invention, the hydrophilic coat region extends from the tip surface to a side surface of the optical member holder.

  As a result, it is possible to reliably discharge the cleaning liquid stored together with the foreign matter or the like on the distal end surface of the endoscope from the distal end surface toward the side surface of the optical member holder.

  In the present invention, an R edge chamfering process is performed on the outer edge of the optical member holder corresponding to at least the hydrophilic coat region on the distal end surface.

  Accordingly, by performing R chamfering on the hydrophilic coat region, it is possible to suppress the pinning effect of the wetness of the portion, and it is possible to reliably discharge the cleaning liquid. Further, in areas other than the hydrophilic coat region, it is possible to adjust the amount of cleaning liquid stored on the tip surface by managing the radius of curvature of the R surface.

  In the present invention, the radius of curvature of the curved surface formed by the R chamfering process in the hydrophilic coat region is larger than that other than in the hydrophilic coat region.

  As a result, in the hydrophilic coat region configured to have a large radius of curvature of the curved surface formed by the R chamfering process, the wetting pinning effect is further reduced, so that the cleaning liquid is more reliably discharged through the hydrophilic coat region. It becomes possible to do.

  Further, according to the present invention, the hydrophilic coat region is provided on the distal end surface at a predetermined distance from the optical member.

  Accordingly, since a gap is provided between the optical member and the hydrophilic coat region, the cleaning liquid supplied to the front end surface is not immediately discharged and covers the entire range of the outer surface of the optical member. Since the outer surface of the optical member is provided with a water-repellent coating, it is difficult for foreign matter such as body fluids to adhere to the optical member. By covering this with the cleaning liquid, the adhered foreign matter is removed from the outer surface of the optical member. It can be liberated.

  In the optical member holder, the water injection portion is opened at the same height as the tip surface, and the cleaning liquid is discharged in a direction perpendicular to the tip surface.

  As a result, when the outer shape of the endoscope is made small, the surface tension acts strongly on the cleaning liquid, and the cleaning liquid discharged from the water injection section is stored in the front end surface without being scattered forward, so that the optical member holder The structure of the part is simplified, and the endoscope can be manufactured at a low cost.

  Further, in the present invention, when the cleaning liquid is injected from the water injection section, the cleaning liquid is pinned at the boundary between the optical member and the optical member holder, and when the cleaning liquid is further injected, the cleaning liquid is the optical member. When the cleaning liquid is pinned at the outer edge of the holder and the cleaning liquid is poured, the cleaning liquid is removed from the tip portion via the hydrophilic coat region.

  As a result, the first pinning is performed at the boundary between the optical member and the optical member holder on the front end surface, and the second pinning is performed at the outer edge of the optical member holder. It is possible to increase the cleaning effect on the outer surface of the optical member by storing the tip surface.

  Further, the present invention is an endoscope provided with an insertion portion to be inserted inside the observation object, and a transparent optical member that guides light to an image sensor, and surrounding and holding the optical member, An optical member holder that forms a distal end surface at the distal end of the insertion portion together with the optical member, and a water injection portion that is provided in the optical member holder and that discharges a cleaning liquid that cleans the outer surface of the optical member at the distal end surface. The outer surface of the optical member is mainly coated with silicon and / or fluorine and carbon, the optical member holder is made of metal, and the optical member is sandwiched between the optical injection portion and the water injection portion. A coating made of silicon and oxygen is applied.

  Accordingly, the cleaning liquid is stored in the outer surface of the optical member having the maximum contact angle with water and the first region having the intermediate contact angle with water, and is finally discharged from the second region having the minimum contact angle with water. Will be. After the foreign material is released from the outer surface of the optical member by the cleaning liquid once stored on the front end surface, the cleaning liquid is reliably discharged from the front end portion, and a clear image can always be taken.

  Further, the present invention is an endoscope provided with an insertion portion to be inserted into an observation target, including a transparent optical region that guides light to an image sensor, and a distal end formed at the distal end of the insertion portion And a water injection part for discharging a cleaning liquid for cleaning the front end surface, the front end surface is provided in a pinning area for temporarily storing the cleaning liquid injected by the water injection part, and in the pinning area And a discharge area for discharging the stored cleaning liquid.

  As a result, an amount of cleaning liquid necessary for cleaning is temporarily stored in the pinning area defined on the front end surface, and then discharged from the discharge area at a stretch, thereby flushing out foreign matter adhering to the outer surface of the optical member. It becomes possible. Furthermore, since it is not necessary to eject the cleaning liquid from the water injection section vigorously, the endoscope can be made thin by forming a thin water pipe that guides the cleaning liquid to the water injection section. Furthermore, the water pressure applied to the cleaning liquid can be kept low.

  Further, the present invention is an endoscope provided with an insertion portion to be inserted inside the observation object, and a transparent optical member that guides light to an image sensor, and surrounding and holding the optical member, An optical member holder that forms a distal end surface at the distal end of the insertion portion together with the optical member, and a water injection portion that is provided in the optical member holder and that discharges a cleaning liquid that cleans the outer surface of the optical member at the distal end surface. The front end surface is provided with a pinning region for temporarily storing the cleaning liquid injected by the water injection unit, and a discharge region for discharging the cleaning liquid stored in the pinning region. is there.

  As a result, an amount of cleaning liquid necessary for cleaning is temporarily stored in the pinning area defined on the front end surface, and then discharged from the discharge area at a stretch, thereby flushing out foreign matter adhering to the outer surface of the optical member. It becomes possible. Furthermore, since it is not necessary to eject the cleaning liquid from the water injection section vigorously, the endoscope can be made thin by forming a thin water pipe that guides the cleaning liquid to the water injection section. Furthermore, the water pressure applied to the cleaning liquid can be kept low.

  According to the present invention, the pinning region includes a first pinning region and a second pinning region, and the first pinning region is surrounded by the second pinning region on the tip surface. is there.

  Accordingly, by configuring the pinning region in a double manner, it becomes possible to reliably store the cleaning liquid on the tip surface and then discharge it.

  In the present invention, the first pinning region is defined by a boundary between the optical member and the optical member holder, and the second pinning region is defined by an outer edge of the optical member holder.

  Accordingly, it is possible to reliably discharge the cleaning liquid from the distal end surface without adding mechanical components to the distal end portion or the flexible portion of the endoscope.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. In addition, about the direction used for description, it shall follow the description of the direction in each figure. Here, “upper” and “lower” correspond to the upper and lower sides of the video processor 3 respectively, and “front (front)” and “rear” refer to the endoscope body 2 (hereinafter referred to as “endoscope 2”). Corresponds to the insertion portion 5 side and the plug portion 6 side.

  FIG. 1 is an overall configuration diagram of an endoscope system 1 using an endoscope 2 according to a first embodiment of the present invention. As shown in FIG. 1, an endoscope system 1 includes an endoscope 2 that is a medical flexible endoscope and still images and moving images obtained by photographing the inside of an observation target (here, a human body). The video processor 3 performs known image processing and the like, and the pump 4 that supplies the cleaning liquid 50 (see FIG. 5) to the distal end portion 12 of the endoscope 2. The endoscope 2 includes an insertion portion 5 that extends substantially in the front-rear direction and is inserted into the observation target, and a plug portion 6 to which the rear portion of the insertion portion 5 is connected.

  The video processor 3 has a socket portion 7 that opens to the front wall 3a. The socket portion 7 is inserted with the rear portion of the plug portion 6 of the endoscope body 2, whereby the endoscope 2 receives power and various signals (video signal, control signal, etc.) with the video processor 3. Sending and receiving is possible. A water supply pipe 39 drawn from the pump 4 is connected to the side wall of the plug portion 6.

  The maximum outer diameter of the insertion portion 5 is 1.8 mm here, and has a flexible soft portion 11 having a rear end connected to the plug portion 6 and a tip portion 12 connected to the tip of the soft portion 11. ing. The flexible part 11 has a length suitable for various surgical procedures.

  The above-described power and various signals are guided from the plug portion 6 to the flexible portion 11 via the transmission cable 13 (described later). The water supply pipe 39 is bent forward in the plug portion 6 and guided to the flexible portion 11. Further, a light source (not shown) configured by an LED (Light Emitting Diode) is accommodated in the plug portion 6, and light emitted from the light source is guided to the flexible portion 11 by an optical fiber bundle 41 (described later). The flexible portion 11 has an internal space with a substantially circular cross section, and an optical fiber bundle 41, a transmission cable 13, and a water pipe 39 extend toward the distal end portion 12 in the internal space.

  FIG. 2 is an exploded perspective view showing the configuration of the distal end portion 12 of the endoscope 2. As shown in FIG. 2, the distal end portion 12 mainly includes an optical member holder 16 that holds the lens unit 15 and the cover glass 35, an image sensor 17 disposed behind the lens unit 15, an image sensor 17, and the image sensor 17. It is comprised with the metal sensor cover 18 which covers the front-end | tip of the transmission cable 13 connected. The transmission cable 13 is electrically connected at the rear part of the image sensor 17.

  The optical member holder 16 supports the holder main body portion 25 having a substantially cylindrical shape, a flange portion 26 provided so as to protrude in the radial direction from the peripheral edge of the front end portion of the holder main body portion 25, and the holder main body portion 25. And a bottom wall portion 27 provided on the lower side thereof, which are integrally formed using a stainless steel material (here, SUS304 (18 chrome stainless steel)) which is a metal material.

  The holder body 25 is provided with a lens mounting hole 31 extending in the front-rear direction, and the lens unit 15 is fitted into the lens mounting hole 31. The lens unit 15 is a cylindrical metal member, and a plurality of (here, three) optical lens groups and diaphragm members (both not shown) having the same diameter and made of an optical material (glass, resin, etc.) Are incorporated in close contact with each other in the direction of the optical axis LC. A cover glass 35 is provided in front of the lens unit 15 as an optical member for protecting the lens unit 15. The cover glass 35 includes a transparent optical region that guides light to the image sensor 17 (at least a region where an optical path of light imaged on the image sensor 17 exists). The cover glass 35 has a substantially disk shape with a top and bottom cut out linearly, and is fitted into an imaging window 36 that opens inside the flange portion 26 of the optical member holder 16 and allows imaging light to enter. The cover glass 35 is fixed to the imaging window 36 with an adhesive, and adhesive pools 43 and 44 are formed on both the left and right sides of the flange portion 26 so as to sandwich the illumination window 37 therebetween.

  In the flange portion 26, an illumination window 37 and a water injection portion 38 are formed in the left-right direction below the imaging window 36. A light emitting end (not shown) of an optical fiber bundle 41 extended from a light source (not shown) provided in the plug portion 6 is fixed to the rear portion of the illumination window 37 in a state where optical coupling is achieved. . The illumination window 37 emits the light transmitted through the optical fiber bundle 41 toward the front imaging region. On the other hand, the water injection part 38 penetrates the flange part 26 back and forth, and is provided so as to protrude from the front surface of the flange part 26, and discharges the cleaning liquid 50 (see FIG. 5) supplied from the pump 4 described above. Here, the cleaning liquid is physiological saline, pure water, or the like, and is appropriately selected according to the observation target into which the insertion portion 5 is inserted. Note that an optical fiber bundle 41 fixed to the illumination window 37 and a water supply pipe 39 fixed to the water injection unit 38 are directed to the rear (that is, the soft part 11 side) below the bottom wall part 27. Stretched.

  A metal holder cover 65 is attached to the holder main body 25 of the optical member holder 16. The holder cover 65 has a substantially C shape in which a part of the cylinder is cut out when viewed from the front-rear direction, and covers the outer periphery of the holder main body 25. The holder cover 65 has an inner diameter that is slightly larger than the outer diameter of the holder body 25. The front edge of the holder cover 65 abuts on the rear surface of the flange portion 26 of the optical member holder 16, and the rear edge of the holder cover 65 is more than the rear edge of the holder main body portion 25 so as to expose the rear portion of the holder main body portion 25. Located in front. Further, the left and right lower edges of the holder cover 65 are respectively connected to the left and right edges of the bottom wall portion 27 and fixed by an adhesive.

  The image sensor 17 is composed of a small CCD (Charge Coupled Device) having a substantially rectangular shape when viewed from the front-rear direction (insertion direction of the insertion portion 5) (here, one side has a size of 1 mm). The image sensor 17 is placed on the upper surface of the extending portion 61 in the optical member holder 16, is in contact with the rear edge of the holder main body portion 25, is positioned in the front-rear direction, and is fixed by an adhesive. Light incident from the cover glass 35 forms an image on the light receiving surface of the image sensor 17 by an optical lens group (not shown) in the lens unit 15 inserted in the lens mounting hole 31. A circuit board 72 provided with a drive circuit and the like for the image sensor 17 is attached to the rear part (back side) of the image sensor 17. The circuit board 72 has a slightly smaller outer shape than the image sensor 17 when viewed from the front-rear direction. The image sensor 17 includes an LGA (Land grid array) on the back surface, and is electrically connected to an electrode pattern formed on the circuit board 72. Further, the front end of the transmission cable 13 is electrically connected to the rear portion (back side) of the circuit board 72 by soldering.

  Since the distal end portion 12 has a configuration in which the image sensor 17 is placed on the upper surface of the extending portion 61 of the optical member holder 16, the image sensor 17 and the optical fiber bundle 41 are partitioned by a metal bottom wall portion 27. . This prevents stray light from entering the light receiving surface of the image sensor 17 even when stray light is emitted from the outer peripheral surface or the like of the optical fiber bundle 41 that passes around the image sensor 17 (here, below). . Further, by placing the image sensor 17 on the upper surface of the extending portion 61, the alignment between the image sensor 17 and the lens unit 15 can be facilitated, and the optical assembly accuracy at the distal end portion 12 can be improved.

  The sensor cover 18 has a shape in which the lower portion of the cylinder is flat so as to form a substantially D shape when viewed from the front-rear direction, and a cylindrical wall 81 located on the upper side and a flat plate-like lower wall located on the lower side 82.

  In assembling the distal end portion 12, first, after the lower surface of the image sensor 17 is bonded to the upper surface of the extending portion 61 of the optical member holder 16, the lens unit 15, the cover glass 35, and the holder cover are attached to the optical member holder 16. 65 is glued. Thereafter, the sensor cover 18 is fitted into the rear part of the optical member holder 16. Thereafter, the distal end portion 12 is covered behind the flange portion 26 by a sheath 14 (see FIG. 3 and the like) made of urethane resin, silicon resin, or the like. The sheath 14 blocks light components incident on the image sensor 17 from directions other than the optical axis LC direction. However, the notches 83 and 84 (see FIG. 4) may be filled with an opaque material to block light.

  FIG. 3 is a lower perspective view showing the configuration of the distal end portion 12 of the endoscope 2, and FIG. 4 is an upper perspective view showing the configuration of the distal end portion 12 of the endoscope 2. 3 and 4 show the tip 12 after assembly. The sheath 14 described above is drawn as an imaginary line. Hereinafter, the configuration of the assembled tip portion 12 will be described with reference to FIGS. 3 and 4 and FIG.

  In the bottom wall portion 27 of the optical member holder 16, a concave guide groove 63 extending in the front-rear direction is formed on the lower surface of the extending portion 61 extending rearward from the rear end of the holder main body portion 25. The front end of the guide groove 63 is connected to the rear end of the flange portion 26, and the optical fiber bundle 41 and the water supply pipe 39 are supported in the left-right direction by the guide groove 63.

  The water supply pipe 39 is made of a resin material having high lubricity such as PTFE (polytetrafluoroethylene) in order to reduce fluid resistance when supplying the cleaning liquid 50 (see FIG. 5). The water supply pipe 39 is connected to a water injection part 38 that protrudes forward from the flange part 26 that forms the tip of the optical member holder 16. Specifically, in the portion where the water injection portion 38 is provided, the flange portion 26 is provided with a through hole in the front-rear direction, and a water supply pipe 39 is inserted into the through hole and fixed with an adhesive. A notch portion 38 a is provided at a portion of the water injection portion 38 facing the cover glass 35, and the cleaning liquid 50 is discharged from the notch portion 38 a to the cover glass 35.

  As described above, the cover glass 35 is fitted on the front surface of the flange portion 26 (that is, the tip of the optical member holder 16). The cover glass 35 is surrounded and held by the flange portion 26, and the outer surface of the cover glass 35 has a thickness that is flush with the surface of the flange portion 26. In other words, the tip surface 40 is constituted by the cover glass 35 and the flange portion 26 at the tip of the optical member holder 16. However, there are tolerances in the thickness of the cover glass 35 and the depth in the front-rear direction of the imaging window 36 (see FIG. 2), and there are also tolerances in the radial sizes of the cover glass 35 and the imaging window 36 as well. doing. Thus, the tip surface 40 is not strictly flat in the relationship between the flange portion 26 and the cover glass 35. Both are bonded by an adhesive, and the tip 12 is kept in a watertight state, but there are minute steps or gaps between them.

  Further, the outer edge of the front end surface 40 (that is, the outer edge of the flange portion 26) is subjected to R chamfering processing with a radius of curvature of R1 (here, R1 = 60 μm) over the entire circumference. In this way, the outer edge of the tip surface 40 is curved and the radius of curvature R1 is defined, so that the cleaning liquid 50 (FIG. 5) is stored in the tip surface 40 when the outer surface of the cover glass 35 is cleaned as described later. The amount of reference) is adjusted.

  At least the outer surface of the cover glass 35 is provided with a water repellent coat. As the water-repellent coating, a reactive curing type fluorine film may be formed, and a commercially available coating agent containing a fluorine-based resin, a silicon-based resin, or a fluorine / silicon-based resin can be suitably used. Here, the fluorine-based resin is mainly composed of fluorine (F) and carbon (C), the silicon-based resin is mainly composed of silicon (Si) and carbon (C), and the fluorine / silicon-based resin is mainly composed of fluorine (F ), Silicon (Si) and carbon (C). The coating type of the water-repellent coating agent can be specified by XPS analysis (X-ray Photoelectron Spectroscopy).

  In the manufacturing process of the endoscope 2, a fluorine coating can be formed on the outer surface of the cover glass 35 by applying a fluorine coating agent to the single cover glass 35 and leaving it for a predetermined time. Note that a water-repellent coating may be applied to the entire cover glass 35 by immersing the cover glass 35 in a coating agent. The water contact angle (contact angle α) of the cover glass 35 to which the water repellent coating is applied is 90 degrees or more. Hereinafter, a region where the water repellent coat is applied in the cover glass 35 (here, at least the entire outer surface of the cover glass 35) is referred to as a “water repellent coat region 51”.

Further, a hydrophilic coat is applied to a portion of the flange portion 26 facing the water injection portion 38 across the cover glass 35 (hereinafter, a region where the hydrophilic coat is applied in the flange portion 26 is referred to as a “hydrophilic coat region 52. "). As the hydrophilic coat, a silica (SiO ₂ ) thin film may be formed, and a hydrophilic coating agent containing a colloidal silica-containing resin can be suitably used. Here, the colloidal silica-containing resin is mainly composed of silicon (Si) and oxygen (O). The composition of the hydrophilic coating agent can be specified by XPS analysis. The water contact angle of the hydrophilic coat region 52 to which the hydrophilic coat has been applied is 40 degrees or less. In the first embodiment, the hydrophilic coat region 52 is provided at the approximate center of a range in which the end surface 40 is parallel to the upper side of the cover glass 35 and the side occupies the left and right sides, and is approximately 470 μm in the outer circumferential direction of the flange portion 26. (That is, a range of a central angle of 30 degrees with respect to a diameter of 1.8 mm of the flange portion 26).

  Further, the hydrophilic coat region 52 is provided in the radial direction of the flange portion 26 so as to be separated from the cover glass 35 by L1 (here, L1 = 100 μm to 200 μm). And the hydrophilic coat area | region 52 is extended from the front end surface 40 to the side surface of the flange part 26 via the outer peripheral part which gave the R chamfer mentioned above, maintaining the width | variety of the left and right in the front end surface 40. The peripheral surface of the flange portion 26 has a width of about 400 μm in the front-rear direction, and the hydrophilic coat region 52 occupies the same range.

  In the manufacturing process of the endoscope 2, a hydrophilic coating agent is applied from the front end surface 40 to the side surface of the flange portion 26 by a so-called inkjet method while adjusting the arrangement angle of the optical member holder 16 that is a workpiece. Thereafter, a silica thin film having a thickness of about 0.5 μm is formed on the surface of the flange portion 26 by leaving it at room temperature for about 3 hours. Since the optical member holder 16 including the flange portion 26 is made of stainless steel, it may be placed in a temperature environment of about 80 ° C. to 300 ° C. when the silica thin film is cured. The water contact angle (contact angle β) of the hydrophilic coat region 52 thus formed is about 10 degrees. In addition, by using an inkjet construction method, the thickness of the hydrophilic coat can be accurately managed, and the interval between the hydrophilic coat region 52 and the cover glass 35 can be ensured with high accuracy. The hydrophilic coat region 52 may be further extended from the outer periphery of the flange portion 26 toward the sheath 14, and the front end portion of the sheath 14 that contacts the rear end of the flange portion 26 is formed on the hydrophilic coating material by a predetermined length. An immersion treatment may be performed.

In addition, the flange part 26 is comprised with stainless steel as mentioned above, and the water contact angle (contact angle (gamma)) of stainless steel is about 60 degree | times. As described above, in the first embodiment, the contact angle with water on the outer surface of the cover glass 35 that is an optical member (that is, the water repellent coating region 51) is α (90 degrees or more), while the flange portion 26 (optical The member holder 16) is provided with a hydrophilic coat region 52 (first region) having a contact angle with water of β (40 degrees or less) at a portion facing the water injection portion 38 with the cover glass 35 interposed therebetween. Further, in the flange portion 26, a portion other than the first region is not coated, and this untreated portion is a region (second region) in which the contact angle with water is γ (60 degrees). . Thus, each contact angle is
α>γ> β (Formula 1)
It has become a relationship.

  FIGS. 5A to 5E are explanatory views showing changes in the form of the cleaning liquid 50 when the cleaning liquid 50 is poured onto the tip surface 40 of the flange portion 26. FIG. 5A shows a state before water injection is started with respect to the front end surface 40, and FIGS. 5B to 5C show that the cleaning liquid 50 is injected from the water injection unit 38, and the cleaning liquid 50 is applied to the front end surface 40. FIG. 5E shows a process in which the cleaning liquid 50 flows out from the tip surface 40. In FIG. 5, the holder main body 25 (see FIG. 2) and the like of the optical member holder 16 are covered with the sheath 14 described above, and the sheath 14 is in contact with the rear end of the flange portion 26 projecting radially at the tip. In contact, it is fixed by an adhesive.

  As shown in FIG. 5 (b), when water injection of the cleaning liquid 50 is started from the water injection part 38 protruding from the flange part 26, the cleaning liquid 50 is injected onto the cover glass 35 facing the notch part 38a. The notch 38a is opened very close to the flange 26 in the front-rear direction, and the water contact angle γ of the flange 26 is greater than the water contact angle α of the water repellent coating region 51 as described above. Therefore, the cleaning liquid 50 spreads not only on the cover glass 35 but also on the flange portion 26, and as a result, the cleaning liquid 50 becomes substantially hemispherical water droplets due to surface tension and is biased near the water injection section 38 (that is, It is stored with a bias toward the water injection section 38 with respect to the optical axis LC. At this time, although the outer edge of the tip surface 40 is R-chamfered, the outer shape of the flange portion 26 is very small as 1.8 mm as described above. No pinning effect ”occurs, and the cleaning liquid 50 is not discharged from the side of the water injection part 38 (the lower part of the flange part 26).

  When the water injection is further continued, as shown in FIG. 5C, the water droplets formed by the cleaning liquid 50 are expanded to cover the entire surface of the cover glass 35. As described above, there is a minute step or gap at the boundary between the surface of the flange portion 26 and the outer surface of the cover glass 35 on the front end surface 40, and this step or the like forms an edge. Is once pinned on the outer periphery of the pin (first pinning). That is, the boundary between the surface of the flange portion 26 and the outer surface of the cover glass 35 defines a pinning region (first pinning region). On the other hand, as shown in FIG. 5B, the cleaning liquid 50 is stored in the vicinity of the water injection section 38 from the beginning of the water injection, and even in the state of FIG. It is deviated from the center of 35 (that is, the optical axis LC) to the water injection section 38 and stored.

  Here, as described above, an interval L <b> 1 is provided between the cover glass 35 (that is, the water repellent coating region 51) and the hydrophilic coating region 52. As will be described later, the cleaning liquid 50 stored in the distal end surface 40 is discharged by contact with the hydrophilic coat region 52, but at the time shown in FIG. 5C, it is between the cover glass 35 and the hydrophilic coat region 52. Since there is a gap (L1), the cleaning liquid 50 cannot come into contact with the hydrophilic coat region 52, and as a result, is stored while covering the entire range of the cover glass 35 without being discharged. The outer surface of the cover glass 35 is hard to adhere foreign substances such as body fluids by the water-repellent coating, and the adhered foreign substances are released from the outer surface of the cover glass 35 by covering the outer surface with the cleaning liquid 50.

  When water injection is further continued from the state of FIG. 5C, the water droplets formed by the cleaning liquid 50 on the tip surface 40 are directed to the outer edge of the flange portion 26 beyond the outer edge of the cover glass 35 as shown in FIG. 5D. To expand the diameter. At this time, the “wetting pinning effect” acts on the outer edge of the flange portion 26 on the front end surface 40 except for the hydrophilic coat region 52, and the cleaning liquid 50 is prevented from flowing out. In this case as well, the water droplets are biased toward the water injection section 38 with respect to the optical axis LC and stored in a substantially hemispherical shape, and the cleaning liquid 50 gradually moves from the water injection section 38 side (lower side) upward toward the flange section 26. It is pinned along the outer periphery (second pinning). In other words, the outer edge of the flange portion 26 defines a pinning region (second pinning region). As is clear from FIGS. 5C and 5D, the first pinning region is surrounded by the second pinning region.

  As described above, the outer periphery of the flange portion 26 is subjected to R chamfering with a radius of curvature R1, and the amount of the cleaning liquid 50 stored in the tip surface 40 can be adjusted by the value of the radius of curvature R1. it can. That is, when the curvature radius R1 is increased, the cleaning liquid 50 can spread to the outer edge of the flange portion 26, so that the amount of the cleaning liquid 50 stored increases. Here, when the water injection is further continued, the cleaning liquid 50 is finally provided in the radial direction facing the water injection part 38 with the cover glass 35 interposed therebetween (that is, arranged at a position farthest from the water injection part 38 as a linear distance). Contacted the hydrophilic coat region 52).

  When water droplets formed by the cleaning liquid 50 expand in diameter and come into contact with the hydrophilic coat region 52, as shown in FIG. 5 (e), the cleaning liquid 50 that has been stored in the tip surface 40 by the “wetting pinning effect” until then is stored. Is discharged from the distal end surface 40 to the side surface of the flange portion 26 via the hydrophilic coat region 52 at once. That is, the hydrophilic coat region 52 functions as a discharge region for the cleaning liquid 50. The outer edge of the distal end surface 40 provided with the hydrophilic coat region 52 is subjected to R chamfering, and the water contact angle α of the hydrophilic coat region 52 is reduced to about 10 degrees. The discharge of the cleaning liquid 50 is not hindered. Further, since the water repellent coating is applied to the outer surface of the cover glass 35, the cleaning liquid 50 does not remain on the cover glass 35.

  Once the stored cleaning liquid 50 starts to flow out, even if water has been continuously injected from the water injection unit 38, it will be immediately discharged from the distal end surface 40. Therefore, the practitioner monitors the screen with the endoscope 2 The water injection may be stopped by operating the pump 4 (see FIG. 1) after confirming that the water has become clear. In this way, since the cleaning liquid 50 that has been stored in the front end surface 40 is rapidly discharged, the foreign matter adhering to the cover glass 35 is reliably removed by the water flow at that time.

  That is, in the endoscope 2 of the first embodiment, when cleaning the outer surface of the cover glass 35, the water force when the cleaning liquid 50 is injected from the water injection unit 38 is not directly used, but the above-described pinning region is used. The amount of cleaning liquid 50 necessary for cleaning is temporarily stored, and foreign matter is discharged (pushed away) by the water flow when the stored cleaning liquid 50 is discharged. In this configuration, there is no need to vigorously discharge the cleaning liquid 50 from the water injection unit 38, so that the water supply pipe 39 (see FIG. 3 and the like) that passes through the flexible portion 11 (see FIG. 1) and is guided to the water injection unit 38 is narrowed. Thus, the diameter of the insertion portion 5 can be reduced. Further, since the water pressure applied to the cleaning liquid 50 can be kept low, the burden on the pump 4 (see FIG. 1) is reduced.

  Thus, when the cleaning liquid 50 is injected from the water injection section 38, the cleaning liquid 50 is first pinned between the cover glass 35 and the optical member holder 16, and when the cleaning liquid 50 is further injected, When the second pinning is performed on the outer periphery of the optical member holder 16 and the cleaning liquid 50 is further poured, the cleaning liquid 50 is discharged from the distal end surface 40 via the hydrophilic coat region 52.

  When the diameter of the tip end portion 12 is further reduced, when the cover glass 35 is simply fitted into the flange portion 26, it is substantially possible to strictly manage a minute step or gap existing between the two in the normal construction method. It becomes difficult. In the first embodiment, the first pinning described above is expressed by utilizing the fact that there is a certain level difference or the like between the two due to the tolerance of the members or the variation in assembly accuracy. However, there may be a case where there is no unevenness or gap between them. In such a case, the entire outer surface of the cover glass 35 may not be completely covered with the cleaning liquid 50 only by the first pinning at the boundary between the cover glass 35 and the flange portion 26. Therefore, in the first embodiment, the second pinning is performed at the outer edge of the flange portion 26 that surrounds the cover glass 35 on the front end surface 40, that is, the pinning region is doubled together with the first pinning region. By configuring, the cleaning liquid 50 is more reliably stored in the front end surface 40 and then discharged.

  In the above description, the outer surface of the cover glass 35 and the flange portion 26 in the front end surface 40 are designed to form a flat surface, but intentionally between the outer surface of the cover glass 35 and the flange portion 26. A step may be provided. For example, when the cover glass 35 is attached to the flange portion 26, the cover glass 35 has a thickness that slightly protrudes from the flange portion 26 in advance, and after the bonding between the two is completed, The length protruding from the flange portion 26 may be managed with high accuracy by polishing the surface. Further, the outer edge of the cover glass 35 thus protruded may be polished and subjected to R chamfering. By managing the radius of curvature of the R surface added by the R chamfering process, the amount of the cleaning liquid 50 stored by the first pinning shown in FIG. 5C can be adjusted to be constant. When the cover glass 35 is polished, the outer surface of the cover glass 35 can be processed into a convex lens shape (including an aspheric lens shape). However, the curvature radius and the like of the convex lens should be set so that the first pinning is performed at the outer edge of the convex lens and the cleaning liquid 50 can cover the entire outer surface. Of course, a predetermined refractive index may be imparted to the cover glass 35 alone from the beginning.

  Further, the cover glass 35 may be recessed from the flange portion 26 to about 10 μm on the front end surface 40. When configured in this way, the hydrophilic coat region 52 may be provided so as to be in contact with the boundary between the cover glass 35 and the flange portion 26. By doing so, the amount of the cleaning liquid 50 necessary for cleaning the outer surface of the cover glass 35 is reduced, so that the time required for cleaning can be shortened. Even if the cover glass 35 is depressed from the flange portion 26, the cleaning liquid 50 is sucked up to the boundary between the two by capillarity, so the cleaning liquid 50 is applied to the cover glass 35 except for the boundary portion between the cover glass 35 and the flange portion 26. It does not remain, and the quality of the captured image is maintained.

  In the first embodiment, the water injection portion 38 is provided at the lower portion of the flange portion 26 and the hydrophilic coat region 52 is provided at the upper portion of the flange portion 26. However, the distal end portion 12 of the endoscope 2 is thinned to about 1.8 mm. When the diameter is increased, the surface tension acts more dominantly on the water droplets of the cleaning liquid 50 stored on the tip surface 40 than the gravity, so that the shape of the water droplets formed by the cleaning liquid 50 changes in substantially the same manner regardless of the direction of gravity. The process from storage to drainage is almost the same. However, in the configuration in which the water injection unit 38 supplies the cleaning liquid 50 along the tip surface 40 as in the first embodiment, depending on the supply amount of the cleaning liquid 50 per unit time, the Coanda effect (the water flow is along the surface of the container). (Flowing phenomenon) may occur. At this time, under the situation where bubbles are mixed in the cleaning liquid 50, it is possible to efficiently remove the bubbles and to efficiently supply the cleaning liquid 50 to the cover glass 35 by providing the water injection part 38 relatively below. Can do.

  Further, in the first embodiment, the R chamfering process is performed over the entire outer edge of the flange portion 26, but the R edge chamfering process is performed on the outer edge other than the portion where the hydrophilic coat region 52 is provided in the flange portion 26. You may comprise so that an edge may remain intentionally without giving. Further, so-called C chamfering may be performed. By not making the chamfer in this way, the second pinning described above can be performed more reliably (the same applies to the second and third embodiments).

  In addition, in order to allow the cleaning liquid 50 to be stored and discharged on the front end surface 40, as described above, the water contact angle α of the cover glass 35 and the first region provided for the purpose of drainage in the flange portion 26 ( In the first embodiment, the water contact angle β of the hydrophilic coat region 52) and the region other than the first region in the flange portion 26 (the region where the hydrophilic coat is not applied in the first embodiment, that is, the second region described above). It is only necessary that the relationship with the water contact angle γ satisfies the relationship of (Equation 1) described above.

  In other words, as long as the requirement of α> γ> β is satisfied, the present invention includes a distal end surface 40 including a transparent optical region (region where an optical path exists) that is configured at the distal end of the insertion portion 5 and guides light to the image sensor 17. And a water injection part 38 for discharging a cleaning liquid 50 for cleaning at least a range corresponding to the optical region of the tip surface 40, and a hydrophilic coating is provided on a part of the tip surface 40 facing the water injection part 38 across the optical region. It can be said that the region 52 is provided.

  Thus, in the first embodiment, the cover glass 35 has a coating agent mainly composed of silicon (Si) and carbon (C), or a coating agent mainly composed of fluorine (F) and carbon (C), or A water-repellent coating using a coating agent mainly composed of fluorine (F), silicon (Si) and carbon (C) is applied (water contact angle is α), and the optical member holder 16 is made of metal stainless steel. In addition, a hydrophilic coating using a coating agent mainly composed of silicon (Si) and oxygen (O) is applied to a portion facing the water injection part 38 across the cover glass 35 with a water contact angle γ. (The water contact angle is β).

  As described above, by applying the water repellent coat, the water contact angle of the water repellent coat region 51 is 90 degrees or more, and by applying the hydrophilic coat, the water contact angle of the hydrophilic coat area 52 is 40 degrees or less. Become. On the other hand, a so-called super water repellent coat having a larger water contact angle than that of the water repellent coat is known. By applying the super water repellent coat, the water contact angle can be increased to 150 degrees or more. In addition, a so-called superhydrophilic coat having a smaller water contact angle than that of the hydrophilic coat is known. By applying the superhydrophilic coat, the water contact angle can be reduced to 10 degrees or less.

  By providing a fine structure on the surface of an object, it is known that the actual contact surface area is enlarged compared to a plane, and the actual free surface energy is larger than that of a plane. By introducing such a structure, the surface with water repellency becomes more water repellant (that is, the contact angle with water becomes larger), and conversely, the surface with hydrophilicity becomes more hydrophilic ( That is, the contact angle with water becomes small. For example, a fractal surface is known as a structure that substantially increases the contact surface area, but since it is difficult to form a strict fractal surface, for example, the number of needle-pointed tips on the surface of an object is, for example, The effect of super water repellency and super hydrophilicity can be obtained by unevenly arranging unevenness of 10 nm to several hundred μm.

  Specifically, the non-uniform irregularities described above can be formed by laminating nano silica fine particles on the target surface (here, the flange portion 26), and the super hydrophilic coating can be applied to the hydrophilic coating region 52. In addition, as a superhydrophilic coat, in addition to this, a so-called polymer brush (a molecular structure in which a polymerization reaction is started from the material surface and a polymer chain is grown in a vertical direction from a substrate and configured like a carpet) is used. Also good.

  As long as the relative relationship of α> γ> β is satisfied, the process described with reference to FIG. 5 is reproduced without applying the water repellent coating to the cover glass 35. For example, the surface of the flange portion 26 made of metal is mirror-finished so that the water contact angle γ of the surface is smaller than the water contact angle α of the cover glass 35 that is not provided with the water-repellent coating. it can. And you may make it provide the hydrophilic coat area | region 52 provided with water contact angle (beta) smaller than this water contact angle (gamma) in a part of flange part 26. FIG. Again, the hydrophilic coat region 52 is coated with a coating agent mainly composed of oxygen and silicon. Note that the super-hydrophilic coat described above may be applied to the hydrophilic coat region 52 instead of the hydrophilic coat.

  Further, as long as the relative relationship of α> γ> β is satisfied, the process described with reference to FIG. 5 is reproduced even when the cover glass 35 is provided with a hydrophilic coat having a water contact angle α. For example, a hydrophilic coat having a water contact angle γ may be applied to the flange portion 26, and the super hydrophilic coat (with respect to the water contact angle β) may be applied to the hydrophilic coat region 52. That is, the degree of hydrophilicity is adjusted by selecting the coating agent in the cover glass 35, the flange portion 26, and the hydrophilic coat region 52. Thus, the present invention can be used as long as a relative relationship of α> γ> β is established (the same applies to the second to fourth embodiments and the sixth embodiment).

(Second Embodiment)
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. FIG. 6 is an upper perspective view showing the distal end portion 12 of the endoscope 2 according to the second embodiment of the present invention. 6 shows a state in which the distal end portion 12 is covered with a sheath 14 (the same applies to FIG. 7). In 2nd Embodiment, since it is the same as that of 1st Embodiment except the periphery of the water injection part 38 and the hydrophilic coat area | region 52 which were provided in the flange part 26, description is abbreviate | omitted.

  As shown in FIG. 6, also in the second embodiment, the optical member holder 16 (see FIG. 1) is provided with a flange portion 26 projecting in the radial direction at the tip thereof, and the flange portion 26 constitutes a tip surface 40 together with the cover glass 35. To do. A water injection portion 38 is provided below the flange portion 26 in the distal end surface 40. However, in the second embodiment, the water injection portion 38 does not protrude from the front surface of the flange portion 26 and opens at the same height as the surface of the flange portion 26 (tip surface 40). In this configuration, the cleaning liquid 50 is discharged from the front end surface 40 in a vertical direction. Also in the second embodiment, the outer shape of the endoscope 2 is configured to be as small as 1.8 mm, and the surface tension acts strongly on the cleaning liquid 50. Therefore, the water injection unit 38 can be adjusted by appropriately adjusting the supply amount of the cleaning liquid 50. It becomes possible to store the cleaning liquid 50 discharged from the front end surface 40 without splashing forward. Thus, in 2nd Embodiment, since the water injection part 38 was comprised by simple opening, the structure of the optical member holder 16 is simplified and it becomes possible to manufacture the endoscope 2 at low cost.

  In addition, in the lower part of the water injection part 38, it is desirable to perform C chamfering on the outer edge of the flange part 26 or leave the edge without chamfering. Since the edge is left in the C chamfering process, the second pinning described in the first embodiment is more easily developed. As a result, the cleaning liquid 50 discharged from the water injection unit 38 is reliably pinned at the outer edge of the lower portion of the flange portion 26. As a result, the cleaning liquid 50 spreads in the direction of the cover glass 35 without being discharged from the front end surface 40, and can finally cover the entire outer surface of the cover glass 35.

  Also in the second embodiment, the outer surface of the cover glass 35 forms a water repellent coating region 51, and the flange portion 26 is provided with a hydrophilic coating region 52 at a portion facing the water injection portion 38 across the cover glass 35. . The hydrophilic coat region 52 is parallel to the upper side of the front end surface 40 where the cover glass 35 is cut out, and is approximately at the center of the range that this side occupies left and right. The cover glass 35 is only L1 (where L1 = 100 μm to 200 μm). They are spaced apart.

  Except for the lower part of the water injection part 38 (the part that is not chamfered or chamfered) and the hydrophilic coat region 52, the outer edge of the flange part 26 has a radius of curvature R1 (here, R1 = 60 μm). Chamfering is applied. In the second embodiment, the hydrophilic coat region 52 is subjected to R chamfering processing having a radius of curvature R2 (here, R2 = 3 mm) larger than R1. For this reason, the hydrophilic coat region 52 forms a groove portion 26 a that is recessed with respect to the region of the curvature radius R <b> 1 in the outer peripheral direction of the flange portion 26. The groove portion 26a occupies a range of about 470 μm in the outer peripheral direction of the flange portion 26. And the hydrophilic coat area | region 52 is extended to the side surface of the flange part 26 via the outer peripheral part which performed R chamfering of the curvature radius R2.

  Thus, by configuring the radius of curvature R2 of the hydrophilic coat region 52 to be large, the “wetting pinning effect” in the hydrophilic coat region 52 is further suppressed. Further, as described above, since the groove portion 26a is as fine as about 470 μm in the outer peripheral direction of the flange portion 26, the suction effect due to capillary action acts strongly in the process of FIG. It becomes possible to discharge reliably.

(Third embodiment)
Hereinafter, a third embodiment of the present invention will be described with reference to the drawings. FIG. 7 is an upper perspective view showing the distal end portion 12 of the endoscope 2 according to the third embodiment of the present invention. In 3rd Embodiment, since the structure of the flange part 26 and the water injection part 38 is the same as that of 2nd Embodiment, description is abbreviate | omitted.

  Also in the third embodiment, the outer surface of the cover glass 35 forms a water repellent coating region 51. Further, the flange portion 26 is provided with a hydrophilic coat region 52 at a portion facing the water injection portion 38 with the cover glass 35 interposed therebetween. However, the hydrophilic coat region 52 is parallel to the upper side where the cover glass 35 is cut off on the front end surface 40, and the range of the central angle of 180 degrees along the outer periphery of the flange portion 26 in the outer peripheral direction from the range where the upper side occupies the left and right. It is provided in AR (that is, a range that occupies the upper half of the flange portion 26).

  The hydrophilic coat region 52 is separated from the cut-out upper side of the cover glass 35 by L1 (100 μm to 200 μm), and is separated from the arc-shaped outer edge portion of the cover glass 35 by L2 (50 μm to 100 μm). Yes. By setting L2> L1, the cleaning liquid 50 (see FIG. 5) can be accurately stored on the tip surface 40. The hydrophilic coat region 52 extends to the side surface of the flange portion 26 via the outer peripheral portion of the flange portion 26.

  In this way, after the first pinning shown in FIG. 5C is performed, the cleaning liquid 50 is discharged from the tip surface 40 at an intermediate stage from FIG. 5C to FIG. 5D. Discharged. For this reason, it is possible to sufficiently cover the outer surface of the cover glass 35 with the cleaning liquid 50 and reduce the amount of the cleaning liquid 50, thereby shortening the cleaning time.

(Fourth embodiment)
Hereinafter, a fourth embodiment of the present invention will be described with reference to the drawings. FIG. 8A is a front view of the distal end portion 12 of the endoscope 2 according to the fourth embodiment of the present invention, and FIG. 8B is a front view of the distal end portion 12 of the endoscope 2 according to the fourth embodiment of the present invention. FIG. FIG. 8B shows a VIIIb-VIIIb cross section shown in FIG. Hereinafter, the front view refers to the endoscope 2 viewed from the distal end side.

  In the fourth embodiment, the optical member holder 16 constituting the distal end portion 12 has a cylindrical shape, and the distal end surface 40 is constituted by the optical member holder 16 and the cover glass 35. The cover glass 35 has a substantially circular outer peripheral shape and is provided slightly offset from the center of the front end surface 40 to the side. In the tip surface 40, two illumination windows 37 are provided in a region formed by biasing the arrangement position of the cover glass 35, and a water injection part 38 projects between the illumination windows 37. The water injection unit 38 opens toward the cover glass 35. As in the first to third embodiments, at least the outer surface of the cover glass 35 is provided with a water-repellent coat, and a portion of the optical member holder 16 facing the water injection portion 38 across the cover glass 35 has a hydrophilic coat region. 52 is provided. The gap described in the first embodiment is formed between the hydrophilic coat region 52 and the cover glass 35.

  Although the cover glass 35 is fitted in the optical member holder 16, in the fourth embodiment, the cover glass 35 is surrounded by a part of the optical member holder 16. In other words, the optical member holder 16 is provided with a notch portion 42, and the outer periphery of the cover glass 35 is bonded to the imaging window 36 (see FIG. 2) provided in the optical member holder 16 and the notch portion 42 is filled. Sealed and fixed by the resin made. As described above, the optical member holder 16 in the fourth embodiment includes the resin fixing portion that fixes the cover glass 35. After fixing the cover glass 35, the outer surface of the filled resin may be polished so as to be flush with the optical member holder 16.

  FIGS. 9A to 9C are explanatory views illustrating a process in which the cleaning liquid 50 is discharged from the distal end surface 40 of the endoscope 2 according to the fourth embodiment of the present invention. As shown in FIG. 9A, when water is injected from the water injection section 38, the discharged cleaning liquid 50 is first pinned at the outer edge of the cover glass 35 (first pinning), and the cleaning liquid 50 is formed. The water droplet expands until it covers the entire surface of the cover glass 35. Thereafter, when water injection is further continued from the state of 9 (a), as shown in FIG. 9 (b), water droplets formed by the cleaning liquid 50 on the front end surface 40 pass over the outer edge of the cover glass 35, and the optical member holder 16 The diameter increases toward the outer edge. At this time, the cleaning liquid 50 is pinned at the outer edge of the optical member holder 16 at the front end surface 40 except for the hydrophilic coat region 52 (second pinning), and the outflow from the front end surface 40 is prevented. The outer edge of the optical member holder 16 is subjected to R chamfering processing with a radius of curvature R1, and the amount of the cleaning liquid 50 stored in the tip surface 40 is adjusted by the value of the radius of curvature R1.

  When the water droplets formed by the cleaning liquid 50 further expand in diameter and come into contact with the hydrophilic coat region 52, the cleaning liquid that has been stored in the front end surface 40 by the “wetting pinning effect” as shown in FIG. 9C. 50 is discharged from the distal end surface 40 to the side surface of the optical member holder 16 through the hydrophilic coat region 52 at once. As described above, also in the fourth embodiment, the first pinning and the second pinning are performed, and the cleaning liquid 50 is stored in the distal end surface 40. Then, the outer surface of the cover glass 35 is cleaned by discharging the stored cleaning liquid 50.

(Fifth embodiment)
Hereinafter, a fifth embodiment of the present invention will be described with reference to the drawings. FIG. 10A is a perspective view of the main part of the distal end portion 12 of the endoscope 2 according to the fifth embodiment of the present invention, and FIG. 10B is the distal end of the endoscope 2 according to the fifth embodiment of the present invention. FIG. 6 is a cross-sectional view of a main part of a portion 12. FIG. 10B shows the Xb-Xb cross section shown in FIG.

  In the first to fourth embodiments, the cover glass 35 is surrounded by at least a part of the flange portion 26 (optical member holder 16). However, in the fifth embodiment, the cover glass 35 is disposed at the tip of the optical member holder 16 as an optical member. A transparent cover member 43 made of resin or glass is provided. The outer diameter of the cover member 43 is substantially equal to the outer diameter of the optical member holder 16 (here, 1.8 mm), and the cover member 43 is fixed to the tip of the optical member holder 16 with an adhesive. That is, in the fifth embodiment, the outer surface of the cover member 43 constitutes the distal end surface 40. The same range in the radial direction as the lens unit 15 in the tip surface 40 is a transparent optical region 53 that guides light to the image sensor 17 (see FIG. 2). A water repellent coat is applied to at least a range corresponding to the optical region 53 on the front end surface 40, and a hydrophilic coat region 52 is provided on a portion of the front end surface 40 that faces the water injection unit 38 across the optical region 53. Is provided. It should be noted that the water repellent coat may be applied to the other area except the hydrophilic coat area 52 on the front end surface 40, and the water repellent coat may be applied to the other part of the cover member 43 other than the hydrophilic coat area 52. Good. Further, the hydrophilic coat region 52 is provided on the side surface of the cover member 43 from the tip surface 40 formed by the cover member 43, but may be extended to the optical member holder 16.

  A water supply pipe 39 is fixed to the side surfaces of the optical member holder 16 and the cover member 43 in an extended state, and the cleaning liquid 50 is applied to the front end face 40 from a water injection portion 38 provided at the front end of the water supply pipe 39. Water is poured. In the fifth embodiment, the tip of the optical fiber bundle 41 (see FIG. 4) is fixed to a recess (not shown) provided on the back surface of the cover member 43, and the illumination window 37 is directly on the tip surface 40. It is not exposed.

  FIGS. 11A to 11C are explanatory diagrams illustrating a process in which the cleaning liquid 50 is discharged from the distal end surface 40 of the endoscope 2 according to the fifth embodiment of the present invention. As shown in FIG. 11A, when water is injected from the water injection unit 38 to the distal end surface 40, the water droplets of the discharged cleaning liquid 50 increase in diameter until the optical region 53 is covered. Thereafter, when water injection is further continued from the state of 11 (a), as shown in FIG. 11 (b), the cleaning liquid 50 is pinned at the outer edge of the cover member 43 except for the hydrophilic coat region 52 (second pin). Stopping) Outflow from the tip surface 40 is prevented. The outer edge of the cover member 43 is subjected to R chamfering with a radius of curvature of R1 (for example, 60 μm), and the amount of the cleaning liquid 50 stored in the distal end surface 40 is adjusted by the value of the radius of curvature R1.

  When the water droplet formed by the cleaning liquid 50 further expands in diameter and comes into contact with the hydrophilic coat region 52, the cleaning liquid that has been stored in the tip surface 40 by the “wetting pinning effect” until then, as shown in FIG. 50 is discharged from the front end surface 40 to the side surface of the cover member 43 via the hydrophilic coat region 52 at once. In the fifth embodiment, the second pinning is performed on the outer periphery of the cover member 43 constituting the distal end surface 40, and the cleaning liquid 50 is stored in the distal end surface 40. And the outer surface (optical area | region 53) of the cover member 43 is wash | cleaned by discharging | emitting the stored washing | cleaning liquid 50. FIG. Thus, in 5th Embodiment, the front end surface 40 has the pinning area | region (namely, outer edge of the cover member 43 except the hydrophilic coating area | region 52) which stores the washing | cleaning liquid 50 poured by the water injection part 38 temporarily, A discharge region (that is, a hydrophilic coat region 52) for discharging the cleaning liquid 50 stored in the pinning region is provided.

(Sixth embodiment)
Hereinafter, a sixth embodiment of the present invention will be described with reference to the drawings. FIG. 12A is a front view of the distal end portion 12 of the endoscope 2 according to the sixth embodiment of the present invention, and FIG. 12B is a front view of the distal end portion 12 of the endoscope 2 according to the sixth embodiment of the present invention. FIG. In addition, FIG.12 (b) has shown the XIIb-XIIb cross section shown to Fig.12 (a).

  In the first to fifth embodiments, the maximum outer diameter of the distal end portion 12 of the endoscope 2 is assumed to be 1.8 mm, but in the sixth embodiment, this is set to about 4 mm, and the cover glass 35 The diameter is 2 mm or less. In the sixth embodiment, the optical member holder 16 constituting the distal end portion 12 has a cylindrical shape, and the distal end surface 40 is constituted by the optical member holder 16 and the cover glass 35. The cover glass 35 has a substantially circular outer peripheral shape, and two illumination windows 37 are provided on the periphery of the optical member holder 16 surrounding the cover glass 35, and a water injection part 38 projects between the illumination windows 37. ing. The water injection unit 38 opens toward the cover glass 35. As in the first to fourth embodiments, at least the outer surface of the cover glass 35 is provided with a water-repellent coat, and a portion of the optical member holder 16 that faces the water injection part 38 across the cover glass 35 is provided with a hydrophilic coat region. 52 is provided. The hydrophilic coat region 52 is provided on the distal end surface 40 formed by the optical member holder 16, but may be extended to the side surface of the optical member holder 16. The gap described in the first embodiment is formed between the hydrophilic coat region 52 and the cover glass 35.

  FIGS. 13A to 13C are explanatory views illustrating a process in which the cleaning liquid 50 is discharged from the distal end surface 40 of the endoscope 2 according to the sixth embodiment of the present invention. As shown in FIG. 13A, when water is injected from the water injection unit 38, the discharged cleaning liquid 50 is pinned at the outer edge of the cover glass 35 (first pinning), and the water droplets formed by the cleaning liquid 50 are The diameter is increased until the entire surface of the cover glass 35 is covered. Thereafter, when water injection is further continued from the state of FIG. 13A, water droplets formed by the cleaning liquid 50 on the tip surface 40 pass over the outer edge of the cover glass 35 as shown in FIG. The diameter increases toward the outer edge. When the cleaning liquid 50 comes into contact with the hydrophilic coat region 52, as shown in FIG. 13 (c), the cleaning liquid 50 stored in the outer edge of the cover glass 35 by the “wetting pinning effect” and thereafter the storage range is expanded is obtained. Then, it is discharged from the outer surface of the cover glass 35 onto the optical member holder 16 through the hydrophilic coat region 52 at once. As described above, in the sixth embodiment, the first pinning is performed on the tip surface 40, and the cleaning liquid 50 is applied to the tip surface 40. Then, the outer surface of the cover glass 35 is cleaned by discharging the stored cleaning liquid 50.

  As mentioned above, although this invention was demonstrated based on specific embodiment, these embodiment is an illustration to the last, Comprising: This invention is not limited by these embodiment. For example, the insertion portion 5 of the endoscope according to the present invention is not limited to the use as a flexible mirror, and can also be used as a rigid endoscope. A part of the configuration described in each embodiment may be combined with other embodiments. Note that all the components of the endoscope 2 according to the present invention shown in the above-described embodiment are not necessarily essential, and can be appropriately selected as long as they do not depart from the scope of the present invention.

  In the endoscope according to the present invention, the cleaning liquid remaining at the distal end portion of the endoscope having a reduced diameter can be surely removed, and a clear image can always be picked up. The present invention can be suitably used for an endoscope that images the inside of an observation target.

1 Endoscope system 2 Endoscope (Endoscope body)
3 Video processor 4 Pump part 5 Insertion part 6 Plug part 11 Soft part 12 Tip part 13 Transmission cable 14 Sheath 16 Optical member holder 17 Image sensor 18 Sensor cover 25 Holder body part 26 Flange part 26a Groove part 35 Cover glass (optical member)
36 Imaging window 38 Water injection part 38a Notch part 39 Water supply pipe 40 Tip surface 42 Notch part 43 Cover member 50 Cleaning liquid 51 Water repellent coating area 52 Hydrophilic coating area 53 Optical area

Claims (13)

An endoscope provided with an insertion portion to be inserted inside an observation target,
A distal end surface including a transparent optical region configured at the distal end of the insertion portion and guiding light to the image sensor;
A water injection part for discharging a cleaning liquid for cleaning a range corresponding to at least the optical region of the tip surface, and
Applying a water-repellent coat to the range of the optical region,
An endoscope comprising a hydrophilic coat region at a portion facing the water injection section across the optical region on the distal end surface. An endoscope provided with an insertion portion to be inserted inside an observation target,
A transparent optical member that guides light to the image sensor;
An optical member holder that surrounds and holds at least a part of the optical member, and forms a distal end surface at the distal end of the insertion portion together with the optical member;
A water injection part that is provided in the optical member holder and discharges a cleaning liquid for cleaning the outer surface of the optical member at the tip surface;
A water repellent coat is applied to the outer surface of the optical member,
The endoscope, wherein the optical member holder includes a hydrophilic coat region at a portion facing the water injection portion with the optical member interposed therebetween.   The endoscope according to claim 2, wherein the hydrophilic coat region extends from the distal end surface to a side surface of the optical member holder.   4. The endoscope according to claim 2, wherein an R chamfering process is performed on an outer edge of the optical member holder corresponding to at least the hydrophilic coat region on the distal end surface.   The endoscope according to claim 4, wherein the hydrophilic coat region has a radius of curvature of a curved surface formed by the R chamfering process larger than that other than the hydrophilic coat region.   The endoscope according to any one of claims 2 to 5, wherein the hydrophilic coat region is provided on the distal end surface by a predetermined distance from the optical member.   7. The optical member holder according to claim 2, wherein the water injection portion is opened at the same height as the tip surface, and the cleaning liquid is discharged in a direction perpendicular to the tip surface. The endoscope according to 1.   When the cleaning liquid is injected from the water injection section, the cleaning liquid is pinned at the boundary between the optical member and the optical member holder, and when the cleaning liquid is further injected, the cleaning liquid is pinned at the outer edge of the optical member holder. The endoscope according to any one of claims 2 to 7, wherein when the cleaning liquid is further poured, the cleaning liquid is removed from the tip through the hydrophilic coat region. mirror. An endoscope provided with an insertion portion to be inserted inside an observation target,
A transparent optical member that guides light to the image sensor;
An optical member holder that surrounds and holds the optical member, and forms a distal end surface at the distal end of the insertion portion together with the optical member;
A water injection part that is provided in the optical member holder and discharges a cleaning liquid for cleaning the outer surface of the optical member at the tip surface;
The outer surface of the optical member is mainly coated with silicon and / or fluorine and carbon,
An endoscope characterized in that the optical member holder is made of metal, and a coating mainly made of silicon and oxygen is applied to a portion facing the water injection portion with the optical member interposed therebetween. An endoscope provided with an insertion portion to be inserted inside an observation target,
A transparent optical region that guides light to the image sensor, and a tip surface formed at the tip of the insertion portion;
A water injection part for discharging a cleaning liquid for cleaning the tip surface,
The front end surface includes a pinning region for temporarily storing the cleaning liquid injected by the water injection unit, and a discharge region for discharging the cleaning liquid stored in the pinning region. Endoscope. An endoscope provided with an insertion portion to be inserted inside an observation target,
A transparent optical member that guides light to the image sensor;
An optical member holder that surrounds and holds the optical member, and forms a distal end surface at the distal end of the insertion portion together with the optical member;
A water injection part that is provided in the optical member holder and discharges a cleaning liquid for cleaning the outer surface of the optical member at the tip surface;
The front end surface includes a pinning region for temporarily storing the cleaning liquid injected by the water injection unit, and a discharge region for discharging the cleaning liquid stored in the pinning region. Endoscope.   11. The pinning region includes a first pinning region and a second pinning region, and the first pinning region is surrounded by the second pinning region on the tip surface. Or the endoscope of Claim 11.   The first pinning region is defined by a boundary between the optical member and the optical member holder, and the second pinning region is defined by an outer edge of the optical member holder. Endoscope.

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