JP2020010745A - Endoscope - Google Patents

Abstract

To protect an imaging device from breakage caused by static electricity, while suppressing enlargement by a simple structure.SOLUTION: An endoscope includes a lens provided on an insertion direction tip toward an analyte, for entering imaging light, an imaging device provided on the rear end of the lens, on which imaging light is focused, a conductive member (for example, a holder 17) for covering the lens and the imaging device, and a grounding member (for example, a metal wire 23) for grounding the conductive member.SELECTED DRAWING: Figure 9

Description

  The present disclosure relates to an endoscope.

  2. Description of the Related Art A reduced-diameter vascular endoscope catheter that uses a guide wire having an outer diameter of about 0.35 mm previously inserted into a blood vessel and enables smooth access to an affected part is known (for example, see Patent Document 1). . The diameter-reduced vascular endoscope catheter has a main body formed of an optical fiber bundle having an outer diameter of about 0.4 mm, and includes a tip having a circular cross section and an optical lens at a tip. The tip is provided with a guidewire passing lumen and a guidewire. The reduced-diameter angioscopic catheter can be easily inserted into a target site along the guide wire by passing the guide wire through the guide wire passing lumen. In a reduced-diameter endoscopic catheter, an image in a blood vessel is captured by an optical lens and transmitted to a proximal side via an optical fiber bundle. The transmitted image can be displayed on a display device or the like.

Utility Model Registration No. 3188206

  However, although an optical lens is disposed at the distal end of the reduced-diameter angioscopic catheter disclosed in Patent Document 1, an imaging element for capturing an image is not disposed. Here, in order to capture a high-quality image of a subject into which the endoscope is inserted (for example, an affected part in a subject, which is a human body), a configuration in which an imaging element is provided at the insertion end of the endoscope is considered. There is a problem that it is necessary to take measures against static electricity in consideration of preventing the image sensor from being broken or otherwise damaged by static electricity from a subject while reducing the size of the image sensor. Patent Literature 1 does not recognize such a problem.

  An object of the present disclosure is to provide an endoscope that has been devised in view of the above-described conventional circumstances and that can protect an imaging element from being damaged by static electricity while suppressing an increase in diameter with a simple structure.

  The present disclosure is provided at the front end in the insertion direction to the subject, a lens to which imaging light is incident, an imaging element provided to be connected to the rear end of the lens, the imaging light is imaged, the lens and An endoscope comprising: a conductive member that covers the imaging element; and a grounding member that grounds the conductive member.

  According to the present disclosure, in an endoscope, an imaging device can be protected from destruction due to static electricity while suppressing an increase in diameter with a simple structure.

FIG. 2 is a perspective view showing an example of an appearance of a distal end side of an endoscope according to Embodiment 1 in an insertion direction. FIG. 1 is a plan view of the endoscope shown in FIG. Side view of the endoscope shown in FIG. Front view of the endoscope shown in FIG. FIG. 3 is a side view of the sheath of FIG. Rear view of the holder viewed from the cross section of the true circle of the sheath Rear view of the holder viewed from the cross section of the oval part of the sheath AA sectional view of FIG. BB sectional view of FIG. Front view of holder according to another configuration example Side sectional view of the holder shown in FIG. Perspective view of another configuration example having a lumen tube as a guidewire lumen Front view of the lumen tube shown in FIG. Side sectional view of FIG. Side view of the imaging unit Side sectional view of the end of the endoscope in the insertion direction showing the insulation structure of the sensor circuit section

  Hereinafter, an embodiment that specifically discloses an endoscope according to the present disclosure will be described in detail with reference to the drawings as appropriate. However, an unnecessary detailed description may be omitted. For example, a detailed description of a well-known item or a redundant description of substantially the same configuration may be omitted. This is to prevent the following description from being unnecessarily redundant and to facilitate understanding of those skilled in the art. The accompanying drawings and the following description are provided for those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

  FIG. 1 is a perspective view showing an example of an appearance of a distal end side in an insertion direction of an endoscope 11 according to the first embodiment. In the following description, the directions used for the description follow the description of the directions in FIG. Here, left and right in the vertical direction shown in FIG. 1 are directed forward from the distal end in the insertion direction of the endoscope 11, the right hand side corresponds to the right, and the left hand side corresponds to the left.

  The endoscope 11 according to the first embodiment includes a lens 13 (see FIG. 8), an imaging element 15 (see FIG. 8), a holder 17, a sheath 19, and a conductive member (for example, a metal cylinder shown in FIG. 11). (A part 21) and a grounding member (metal wire 23 in FIG. 9) as main components.

  The endoscope 11 includes a guide catheter (not shown) inserted to receive the guide wire 25 after the guide wire 25 is inserted into a subject (for example, a human body) during an operation or an examination. And can be used. The guide catheter is inserted through a blood vessel in the subject, for example. To give a specific example of dimensions, the guide catheter has an outer diameter of, for example, 1.8 mm and an inner diameter of 1.5 mm. A guide wire 25 is passed through the guide catheter. The guide wire 25 has an outer diameter of, for example, 0.35 mm. The endoscope 11 is passed through the guide catheter together with the guide wire 25. For this reason, the endoscope 11 has a guide wire hole 27 through which the guide wire 25 passes. Since the endoscope 11 according to the first embodiment is provided with the guide wire hole 27 and is passed through the guide catheter, the maximum outer diameter D (see FIG. 3) is set to, for example, 1.35 mm or less.

  In the endoscope 11, a holder 17 is provided at the distal end of the insertion section 29 in the insertion direction. The insertion section 29 is almost entirely covered by the sheath 19. The sheath 19 is formed into a tubular shape (that is, a tubular shape) by, for example, a flexible resin material. The sheath 19 can be provided with a single wire, a plurality of wires, or a braided tensile wire on the inner peripheral side, for example, for the purpose of imparting strength. As the tensile strength line, aramid fiber such as poly-p-phenylene terephthalamide fiber, polyarylate fiber, polyparaphenylene benzobisoxazole fiber, polyester fiber such as polyethylene terephthalate fiber, nylon fiber, tungsten fine wire or stainless steel fine wire And the like. The sheath 19 is a perfect circle portion 31 whose cross section in a direction perpendicular to the axis or the optical axis of the lens 13 is a perfect circle. However, since the sheath 19 has flexibility, the sheath distal end serving as a connection portion with the holder 17 will be described later. As a result, the flat portion 33 has an elliptical cross section.

  The holder 17 to which the sheath 19 is connected exposes the lens cover glass 35 on the distal end surface. A lens cover glass 35 may be integrally fixed to the surface of the lens 13 as the imaging optical system. In the first embodiment, the lens cover glass 35 integrally fixed to the lens 13 is exposed on the distal end surface of the holder 17. The lens 13 is provided at the distal end in the insertion direction, and takes in imaging light (that is, light from a subject such as an affected part in the subject enters). The light emitting end faces of a plurality of optical fibers for illumination 37 continuously arranged vertically in the left and right directions with the lens cover glass 35 interposed therebetween are arranged on the tip end face of the holder 17.

  The holder 17 has a raised portion 41 on the upper side of an elliptical flat cylindrical portion 39 whose left and right sides are long axes. The guide wire hole 27 is bored through the raised portion 41 in the extending direction of the sheath 19. The holder 17 is configured to cover the lens 13 and the imaging element 15 constituting the distal end of the endoscope 11 and to include a guide wire hole 27 through which a guide wire 25 passes.

  FIG. 2 is a plan view of the endoscope 11 shown in FIG. At the sheath distal end (that is, the distal end portion of the sheath 19), the sheath 19 becomes a flat portion 33 that is wider than the true circular portion 31 in the left-right direction. That is, the sheath 19 has the outer shape of the flat portion 33 at the sheath distal end (see above), but the flat portion 33 converges from the sheath distal end to the rear end side, and has the outer shape of the perfect circle portion 31. The holder 17 is slightly larger in the left-right direction than the flat portion 33, but may be formed with the same width as the flat portion 33. The guide wire hole 27 is formed at the top of the raised portion 41 at the center in the direction along the axis of the holder 17.

  FIG. 3 is a side view of the endoscope 11 shown in FIG. In the holder 17, the raised portion 41 has a mountain shape. In the endoscope 11 according to the first embodiment, the total height up to the top of the holder 17 is set to the above-described maximum outer diameter D (that is, the maximum outer diameter of the endoscope 11). The inclination angle θ of this chevron is the same on the front end side in the insertion direction and on the rear end side in the insertion direction. The inclination angle θ is formed such that the included angle between the axis of the holder 17 and the holder 17 is, for example, about 30 degrees. Thereby, the endoscope 11 enables smooth insertion and extraction into blood vessels and catheters. The inclination angle is not limited to the above-described angle value, and the inclination angle θ of the chevron may not be the same on the front end side in the insertion direction and on the rear end side in the insertion direction.

  FIG. 4 is a front view of the endoscope 11 shown in FIG. The holder 17 has only two holes, the guide wire hole 27 and the observation hole 43 in which the lens cover glass 35 and the illumination optical fiber 37 are arranged, on the distal end surface. The lens cover glass 35 and the optical fiber 37 for illumination arranged inside the observation hole 43 are stably fixed by the black resin 45 filled in the observation hole 43.

  The holder 17 has a width W2 left and right sandwiching the guide wire hole 27 smaller than a width W1 left and right sandwiching the observation hole 43 in a front view of a distal end surface in which the guide wire hole 27 and the observation hole 43 are vertically arranged. You. Thus, the holder 17 has a so-called teardrop outer shape when viewed from the front, and a transparent liquid flows into the gap between the catheter or blood vessel and the endoscope 11 to easily maintain the field of view.

  FIG. 5 is a side view in which the sheath 19 of FIG. 3 is cut away. The holder 17 has a cylindrical sheath fitting portion 47 that projects rearward from the rear end of the flat cylindrical portion 39 (an example of a camera housing portion). The sheath distal end is fitted and connected to the outer periphery of the sheath fitting portion 47. The holder 17 has a flat cylindrical portion 39, a raised portion 41, and a sheath fitting portion 47 integrally formed of metal. For example, SUS (stainless steel) can be used as the metal. The sheath 19 has a thickness t of, for example, 75 μm. The sheath 19 is connected to a sheath fitting portion 47 extending from the rear end of the holder 17, and penetrates the cable 49 and the illumination optical fiber 37 electrically connected to the image sensor 15.

  FIG. 6 is a rear view of the holder 17 as viewed from a cross section of the round portion 31 of the sheath 19. The sheath 19 has a round portion 31 on the rear end side in the insertion direction. The sheath 19 is gradually flattened toward the sheath fitting portion 47 and forms an ellipse following the outer periphery of the sheath fitting portion 47 at the fitting portion with the sheath fitting portion 47. The round part 31 is almost in contact with the guide wire hole 27. The guide wire hole 27 is formed in the raised portion 41 leaving the bridge portion 51 at the top. The thickness n of the bridge portion 51 is set to, for example, 50 μm.

  The image sensor 15 can be seen inside the sheath fitting portion 47. The imaging device 15 has, for example, four bumps 53 on the back surface. In each of the bumps 53, a plurality of core wires 55 bundled as a cable 49 are fixed by soldering. As a result, the cable 49 and the sensor circuit unit 57 (see FIG. 15) of the image sensor 15 are electrically connected. A ground member is passed through the sheath 19 along the cable 49. The grounding member is conductively connected to the sheath fitting portion 47 of the holder 17.

  FIG. 7 is a rear view of the holder 19 as viewed from a cross section of the elliptical portion of the sheath 19. The sheath fitting portion 47 projecting rearward from the holder 17 has a cross-sectional shape in a direction orthogonal to the axis of the sheath 19, and is formed in an elliptic cylindrical shape in which one end of the short axis of the sheath 19 is close to the guide wire hole 27. . The annular portion sandwiched between the cross section of the sheath 19 in FIG. 7 and the end face of the sheath fitting portion 47 gradually decreases in diameter toward the sheath fitting portion 47 and continues. It is.

  FIG. 8 is a sectional view taken along line AA of FIG. In the endoscope 11, the lens cover glass 35 and the lens 13 are formed in the same outer shape by a flat rectangular prism (for example, a regular rectangular prism) that is short in the axial direction. The lens 13 has a concave portion on the surface opposite to the lens cover glass 35. The lens 13 has a convex lens surface 59 facing the image sensor 15 on the bottom surface of the concave portion. The convex lens surface 59 is disposed so as to face the image sensor 15 via air, and functions as an effective element portion of the lens 13 (that is, a portion that refracts incident light).

  The surface of the imaging element 15 facing the lens 13 is a light receiving surface. The imaging element 15 is provided on the back of the lens 13 so that imaging light is focused on the light receiving surface. In the imaging element 15, a sensor cover glass 61 is integrally fixed to a light receiving surface. The strength of the image sensor 15 is ensured by being integrated with the sensor cover glass 61. The lens cover glass 35, the lens 13, the sensor cover glass 61, and the imaging device 15 form an imaging unit 63.

  FIG. 9 is a sectional view taken along line BB of FIG. The camera housing part 65 is formed in the holder 17 inward. The camera housing section 65 houses the imaging unit 63. The camera housing section 65 is formed inside the flat cylindrical section 39 described above. The distal end of the holder 17 is connected to the sheath fitting portion 47 extending from the rear end of the camera housing portion 65. The endoscope 11 is substantially in contact with the guide wire 25 at the round portion 31 of the sheath 19. In the endoscope 11, the total height H including the guide wire 25 in the perfect circular portion 31 is, for example, about 1.3 mm.

  The endoscope 11 is deformed into a horizontally long ellipse by fitting the sheath 19 into the sheath fitting portion 47 below the guide wire 25 passed through the guide wire hole 27. As a result, a gap 67 is formed between the guide wire 25 and the sheath 19 at the distal end in the insertion direction of the endoscope 11.

  The endoscope 11 includes a conductive member that covers the lens 13 and the imaging device 15. The conductive member is grounded to GND (ground) via a grounding member. In the first embodiment, this conductive member serves as holder 17.

  In the first embodiment, the ground member is the metal wire 23. The metal wire 23 extends along the cable 49 in the sheath 19. The metal wire 23 is connected to an insulated ground part of a circuit to be insulated provided in a video processor (not shown) to which the endoscope 11 is connected via a plug part (not shown) whose base end is connected to the insertion part 29. Connected.

  In the endoscope 11, the whole of the holder 17 formed of metal can be a portion to which static electricity is applied. In the endoscope 11, for example, at the time of an operation or an inspection, static electricity is applied to the holder 17, and a current flowing from the holder 17 to the metal wire 23 is released to the insulated earth portion of the circuit to be insulated via the plug portion. Accordingly, application of static electricity to the sensor circuit unit 57 of the imaging element 15 is suppressed.

  For the endoscope 11 used as a medical endoscope, it is necessary to consider, for example, preventing leakage current from flowing into a patient as a subject. Therefore, the metal wire 23 for inducing static electricity and the holder 17 serving as a patient contact portion may be insulated by providing a gap G (see FIG. 16). The metal wire 23 for inducing static electricity is connected to an insulated grounding portion having sufficiently reduced leakage current through an electrical insulating circuit. In this way, the endoscope 11 is provided with the metal wire 23 for inducing and releasing static electricity between the holder 17 and the endoscope 11, and is released to the insulated grounding portion. By providing such a configuration, the endoscope 11 solves a problem peculiar to the electronic endoscope in which the image pickup device 15 is mounted at the tip, and protects the image pickup device 15 so that static electricity does not flow. It has been done.

  In addition, the conductive member may be directly electrically connected without providing the gap G between the conductive member and the ground member. In this case, a protection element such as an ESD (Electro Static Discharge) suppressor is provided between the metal wire 23 and GND.

  FIG. 10 is a front view of a holder 69 according to another configuration example. In this configuration example, the guide wire hole 27 is not provided in the holder 69. The configuration including the conductive member and the grounding member at the distal end in the insertion direction is also useful for an endoscope having a structure having no guide wire hole 27 as shown in FIG. In this case, the holder 69 is formed, for example, in a cylindrical shape. The holder 69 may be made of metal or resin. When the holder 69 is made of resin, the metal cylindrical portion 21 which is a rigid and conductive member is provided inside the holder 69. The metal cylindrical portion 21 can have a thickness of, for example, 30 to 50 μm.

  FIG. 11 is a side sectional view of the holder 69 shown in FIG. The metal cylindrical portion 21 accommodates the imaging unit 63 inside. In the imaging unit 63, for example, a part of the lens cover glass 35, the lens 13, and the sensor cover glass 61 are stably fixed to the inner periphery of the metal cylindrical portion 21 by the black resin 45. The rear end of the metal cylindrical portion 21 that is sufficiently separated from the image sensor 15 of the image pickup unit 63 is connected to the metal wire 23.

  FIG. 12 is a perspective view of another configuration example having a lumen tube 71 as a guidewire lumen. Note that the endoscope 11 may include the guide wire hole 27 by using a holed member in which a plurality of holes are formed. This perforated member can be referred to as a guidewire lumen. Among the guidewire lumens, a tube-shaped one in particular is referred to as a lumen tube 71. The endoscope 11 uses the lumen tube 71 at the rear end of the elongated cylindrical holder 73 that is the tip in the insertion direction, so that the guide wire 25 can pass through the guide wire hole 27 of the lumen tube 71.

  FIG. 13 is a front view of the lumen tube 71 shown in FIG. In this case, the holder 73 can have a simple structure without the raised portion 41. The holder 73 has an observation hole 43 for disposing the lens cover glass 35 and the optical fiber 37 for illumination on the distal end surface. The lens cover glass 35 and the optical fiber 37 for illumination arranged inside the observation hole 43 are stably fixed by the black resin 45 filled in the observation hole 43.

  FIG. 14 is a side sectional view of FIG. The endoscope 11 has a tube equivalent to the sheath 19, and the sheath 19 can be omitted by using a lumen tube 71 in which the guide wire hole 27 is formed only at the distal end in the insertion direction of the tube. Thereby, the holder 73 can be simplified.

  In other words, in the endoscope 11 shown in FIGS. 1 to 9, the conductive member (that is, the holder 17) in which the guide wire hole 27 is formed also serves as the guide wire lumen. On the other hand, in the configuration using the lumen tube 71, the holder 73 can be simplified, but the guide wire hole forming portion of the lumen tube 71 becomes long, and the bending performance decreases. On the other hand, according to the endoscope 11 in which the guide wire hole 27 is formed in the metal holder 17 described above, since the entire length of the holder 17 is short, good bending performance is secured.

  FIG. 15 is a side view of the imaging unit 63. In the endoscope 11, in the imaging unit 63, the lens 13 is integrally fixed to a light receiving surface of the imaging device 15. More specifically, the integral lens cover glass 35 and the lens 13 formed with the same outer shape are fixed to the sensor cover glass 61 fixed to the light receiving surface of the imaging device 15. Here, in the imaging unit 63, the outer shapes of the lens cover glass 35 and the lens 13 are formed larger than the sensor cover glass 61. Further, the sensor cover glass 61 is formed to be larger than the outer shape of the sensor circuit unit 57 of the image sensor 15. That is, the outer shape of the lens 13, the sensor cover glass 61, and the sensor circuit portion 57 gradually decreases via the step portion 75.

  FIG. 16 is a side cross-sectional view of the distal end in the insertion direction of the endoscope 11 showing the insulating structure of the sensor circuit unit 57. In the endoscope 11, the sensor circuit portion 57 of the imaging element 15 does not contact the conductive member (the inner surface of the holder 17).

  Further, the endoscope 11 has a structure in which the conductive member (the sheath fitting portion 47) and the grounding member (the metal wire) are compared with the insulation resistance (distance L) between the sensor circuit unit 57 and the conductive member (the inner surface of the holder 17). 23) The insulation resistance (gap G) is small. That is, the dielectric breakdown distance between the holder 17 and the metal wire 23 is set smaller than the dielectric breakdown distance between the holder 17 and the sensor circuit unit 57 (L> G).

  Next, the operation of the configuration of the endoscope 11 according to the first embodiment will be described.

  The endoscope 11 according to the first embodiment has a lens 13 that is provided at a distal end in a direction of insertion into a subject and receives imaging light. The endoscope 11 is provided so as to be connected to the rear end of the lens 13 and has an imaging element 15 on which imaging light is focused. The endoscope 11 has a holder 17 that covers the lens 13 and the imaging element 15 and has a guide wire hole 27 through which a guide wire 25 inserted into the subject passes. The endoscope 11 has a flexible tubular sheath 19 connected to the rear end of the holder 17 and through which a cable 49 electrically connected to the imaging device 15 is inserted.

  In endoscope 11 according to Embodiment 1, sheath 19 is connected to the rear end of holder 17. Since the sheath 17 is connected to the rear end of the holder 17, the outer diameter of the holder 17 can be reduced by the thickness of the sheath 19 on both sides in the diametrical direction, as compared with a configuration in which the sheath 19 is covered and attached to the outer periphery of the sheath 19. Enlargement of the maximum outer diameter of the mirror can be suppressed. In addition, since the endoscope 11 accommodates both the lens 13 and the imaging element 15 in the holder 17 provided at the distal end in the insertion direction, the endoscope 11 guides the imaging light using an optical fiber bundle as in the related art. It is possible to obtain a high-quality captured image as compared with an imaging method in which a captured image is displayed by using a digital camera. Further, in the endoscope 11, since the holder 17 includes the guide wire hole 27, the guide wire 25 can be passed through the guide wire hole 27, and can be easily inserted into a target portion along the guide wire 25.

  Therefore, according to the endoscope 11 according to Embodiment 1, in the configuration having both the lens 13 and the imaging element 15 at the distal end and including the guide wire hole 27, the distal end in the insertion direction can be reduced in diameter.

  Further, in the endoscope 11, the holder 17 has a camera housing section 65 for housing the lens 13 and the imaging element 15 inside, and a front end of the sheath 19 is connected to a rear end of the camera housing section 65. .

  In this endoscope 11, the distal end of the sheath 19 is connected to the rear end of the camera housing 65. The distal end in the insertion direction is composed of a lens 13 and an image sensor 15 and a holder 17 that covers them. Thereby, the holder 17 can form the camera housing portion 65 in a size that houses only the minimum necessary components, and the endoscope 11 can easily be reduced in diameter and size at the distal end in the insertion direction.

  In the endoscope 11, the holder 17 has a cylindrical sheath fitting portion 47 that projects rearward from the rear end of the camera housing portion 65. The distal end of the sheath 19 is fitted and connected to the outer periphery of the sheath fitting portion 47.

  In the endoscope 11, the camera housing portion 65 has the sheath fitting portion 47 protruding rearward from the rear end. The sheath fitting portion 47 is formed in a cylindrical shape. The holder 17 can integrally form the camera housing portion 65 and the sheath fitting portion 47. The sheath 19 is fixed to the outer periphery of the sheath fitting portion 47 by fitting the inner periphery thereof. The sheath fitting portion 47 is formed so that the outer shape of the fitted sheath 19 does not protrude outside the outer shape of the holder 17. For fixing the sheath 19 and the sheath fitting portion 47, for example, an adhesive is used. The sheath fitting portion 47 can secure a large bonding area by fitting around the outer periphery of the sheath fitting portion 47. Thereby, the connection strength between the sheath 19 and the holder 17 can be ensured to be greater than that in the connection structure in which the end faces abut each other. Also, since a large bonding area can be secured, the waterproof performance at the joint between the holder 17 and the sheath 19 can be improved.

  In the endoscope 11, the cross-sectional shape in a direction orthogonal to the axis of the sheath fitting portion 47 is an ellipse having one end of the short axis approaching the guide wire hole 27.

  In this endoscope 11, the cross-sectional shape of the sheath fitting portion 47 is elliptical. Accordingly, the cross-sectional shape of the sheath 19 fitted on the outer periphery of the sheath fitting portion 47 also becomes an ellipse following the shape. This ellipse is oriented such that one end of the short axis is close to the guide wire hole 27. Therefore, below the guide wire 25 passed through the guide wire hole 27, the sheath 19 connected to the sheath fitting portion 47 is deformed into a horizontally long ellipse. Thereby, a gap 67 is formed between the guide wire 25 and the sheath 19. In the endoscope 11, the guide wire 25 and the sheath 19 do not interfere with each other due to the gap 67, and the endoscope 11 can be easily bent at a portion immediately rearward of the holder 17 and the insertability is improved. In addition, since the vertical dimension of the sheath 19 is reduced, the outer diameter of the distal end of the endoscope 11 can be reduced.

  In addition, the endoscope 11 passes through a guide catheter, and allows a transparent liquid to flow into a blood vessel from the guide catheter to maintain a visual field. At this time, the outer shape in a front view is a so-called teardrop shape, and it is possible to suppress the bias in the liquid discharge direction.

  In the endoscope 11, the holder 17 is made of metal (that is, formed using a rigid metal).

  In the endoscope 11, the guide wire 25 is passed through the guide wire hole 27, and the holder 17 is inserted into the target site along the guide wire 25. At this time, in the holder 17, shaving of the guide wire hole 27 due to sliding contact with the guide wire 25 is suppressed as compared with the case where the holder 17 is made of resin or ceramic.

  Further, in the endoscope 11, the holder 17 has only two holes, the guide wire hole 27 and the observation hole 43 in which the lens 13 and the illumination optical fiber 37 are arranged, on the distal end surface.

  In the endoscope 11, the distal end surface of the holder 17 has only the observation hole 43 in addition to the guide wire hole 27. The lens 13 and the illumination optical fiber 37 are arranged in the observation hole 43. The optical fibers for illumination 37 are generally arranged in a pair with the lens 13 interposed therebetween in order to obtain a good illumination effect. When these dedicated holes are formed in the holder 17, for example, four holes are required on the tip end surface. It is desirable that the vascular endoscope passed through the guide catheter (about 1.5 mm in inner diameter) has an outer diameter of at least 1.4 mm or less. Forming four holes in such a small-diameter distal end surface may be an obstacle to reducing the manufacturing cost of the holder 17 and realizing mass productivity. Therefore, the endoscope 11 has the lens 13 and the illumination optical fiber 37 arranged in the same room as one observation hole 43. Thereby, in the endoscope 11, the processing limit is eased, and the reduction of the manufacturing cost and the securing of the mass productivity are realized. The observation hole 43 is filled with a black resin 45. The black resin 45 filled in the observation hole 43 forms a partition separating the lens 13 and the illumination optical fiber 37. Thereby, in the endoscope 11, incidence of illumination light from the illumination optical fiber 37 to the lens 13 is suppressed. Further, by coating the periphery of the illumination optical fiber 37 with black, the incidence of illumination light from the illumination optical fiber 37 to the lens 13 can be suppressed. In that case, the resin to be filled does not need to be black.

  Further, the holder 17 is formed such that, in a front view of the distal end surface in which the guide wire hole 27 and the observation hole 43 are vertically arranged, the left and right widths sandwiching the guide wire hole 27 are smaller than the left and right widths sandwiching the observation hole 43. You.

  In the endoscope 11, the holder 17 is formed such that the left and right widths sandwiching the guide wire hole 27 are smaller than the left and right widths sandwiching the observation hole 43. That is, the holder 17 is formed as a so-called teardrop shape in a front view. As described above, the endoscope 11 passes through the guide catheter, and allows the transparent liquid to flow into the blood vessel from the guide catheter to maintain the visual field. At this time, since the endoscope 11 has a teardrop shape, a sufficient gap can be secured between the endoscope 11 and the inner diameter of the guide catheter which is a circumscribed circle. Thereby, the endoscope 11 can more reliably secure a fluid discharge space as compared with the case where the front view of the holder 17 is a perfect circle.

  In addition, the endoscope 11 has a lens 13 that is provided at the distal end in the direction of insertion into the subject and receives the imaging light. The endoscope 11 is provided so as to be connected to the rear end of the lens 13 and has an imaging element 15 on which imaging light is focused. The endoscope 11 has a conductive member (for example, the holder 17 and the metal cylindrical portion 21) that covers the lens 13 and the imaging device 15. The endoscope 11 has a ground member (for example, a metal wire 23) for grounding the above-described conductive member to GND (ground).

  In the endoscope 11, an imaging element 15 provided with the lens 13 at the distal end in the insertion direction is covered with a conductive member. This conductive member is grounded to GND (ground) via a grounding member. The grounding member may be, for example, a metal braid or the like of the braid tube in addition to the metal wire 23. The conductive member that covers the lens 13 and the imaging element 15 receives imaging light (that is, light from a subject such as an affected part in the subject) from the front of the distal end in the insertion direction, and extends the ground member backward in the insertion direction. To be located. For this reason, the conductive member is opened at the front end in the insertion direction and the rear end in the insertion direction. That is, the conductive member has a tubular shape. When the conductive member is, for example, a cylinder, the conductive member can surround the imaging element 15 from a direction of 360 degrees around the axis. Thus, the image sensor 15 can accurately shield static electricity coming from a 360-degree direction. In addition, the endoscope 11 can be made smaller than a structure in which a sufficient space is set without providing a conductive member and the endoscope 11 is insulated. As a result, the endoscope 11 can improve the operation reliability of the imaging element 15 while reducing the diameter.

  Therefore, according to the endoscope 11 according to the first embodiment, the imaging device 15 can be protected from destruction due to static electricity while a large diameter is suppressed with a simple structure, and safe use can be ensured.

  Further, since the image pickup device 15 is surrounded by the inside of the conductive member, static electricity does not fly from the grounding member which is conductively connected to the end of the conductive member. For this reason, a bare conductor or the like from which the insulating coating is omitted can be used as the grounding member. As a result, the diameter of the sheath 19 through which the ground member is inserted can be reduced because the configuration of the insulating coating is omitted from the outer periphery of the ground member.

  The endoscope 11 further has a guide wire lumen provided at the distal end in the insertion direction and having a guide wire hole 27 through which the guide wire 25 passes.

  In the endoscope 11, a guide wire lumen is provided at the distal end in the insertion direction. In this case, the conductive member can be provided inside the guide wire lumen. The material of the guide wire lumen may be resin or metal. The guide wire lumen may be, for example, a flexible resin lumen tube 71. The lumen tube 71 may be formed integrally with the sheath 19 connected behind the conductive member. The lumen tube 71 has a guide wire hole 27 through which the guide wire 25 passes. Since the endoscope 11 includes the lumen tube 71, the conductive member, and the imaging device 15 at the distal end in the insertion direction, a high-quality observation image can be obtained while protecting the imaging device 15 from static electricity. In addition, the endoscope 11 allows the guide wire 25 to pass through the guide wire hole 27 of the lumen tube 71 and be easily inserted into a target portion along the guide wire 25.

  In the endoscope 11, the conductive member having the guide wire hole 27 also serves as a guide wire lumen.

  In the endoscope 11, a guide wire hole 27 is formed in the conductive member. The conductive member in which the guide wire hole 27 is formed is equivalent to the holder 17 described above. That is, the endoscope 11 can omit the lumen tube 71 by forming the distal end in the insertion direction using the holder 17.

  In addition, in the endoscope 11, the sensor circuit portion 57 of the imaging element 15 does not contact with the conductive member (that is, the endoscope 11 is disposed apart from the conductive member).

  In the endoscope 11, static electricity that is flying to the conductive member and flowing to the grounding member is prevented from flowing to the image sensor 15 by short-circuiting. This prevents damage such as destruction of the image sensor 15 due to static electricity flowing to the sensor circuit section 57.

  In addition, the endoscope 11 is integrally fixed and arranged so that the lens 13 forms imaging light (that is, light from a subject such as an affected part in the subject) on the light receiving surface of the imaging element 15. . The outer diameter of the outer shape of the lens 13 (that is, the cross-sectional shape in a direction orthogonal to the optical axis of the lens 13) is equal to the outer diameter of the sensor circuit portion 57 of the image sensor 15 (that is, the direction perpendicular to the optical axis of the lens 13). (Cross-sectional shape).

  In the endoscope 11, in the manufacturing process, the integrated lens 13 and the imaging device 15 are inserted and assembled as an imaging unit 63 inside the conductive member. In this case, even if the imaging unit 63 contacts the inner surface of the conductive member, the lens 13 contacts the conductive member, and the sensor circuit unit 57 does not easily contact the inner surface of the conductive member. Thereby, at the time of mass production, the risk that the sensor circuit portion 57 contacts the conductive member can be reduced, and the productivity can be improved.

  In addition, in the endoscope 11, the insulation resistance between the conductive member and the ground member is smaller than the insulation resistance between the sensor circuit unit 57 and the conductive member.

  In the endoscope 11, the distance (gap G) between the conductive member and the ground member is set smaller than the distance L between the sensor circuit unit 57 and the conductive member. There is no particular difficulty in electrically connecting the conductive member and the ground member. If the conductive member and the grounding member are electrically connected, a small distance between the sensor circuit unit 57 and the conductive member may be ensured. For example, by securing a space distance of 10 μm, a withstand voltage of 200 V can be obtained. As a result, a large current due to the high voltage of the static electricity can reliably flow through the ground member, and the image sensor 15 can be protected from destruction.

  The grounding member of the endoscope 11 is a metal wire 23.

  In the endoscope 11, since the metal wire 23 is used as the grounding member, it is possible to simultaneously obtain the grounding function of the conductive member and the pushability (so-called pushability that does not easily buckle) due to the rigidity of the metal wire 23. it can.

  Although various embodiments have been described with reference to the drawings, it is needless to say that the present disclosure is not limited to such examples. It is clear that those skilled in the art can conceive various changes, modifications, substitutions, additions, deletions, and equivalents within the scope of the claims. Naturally, it is understood that they belong to the technical scope of the present disclosure. Further, the components in the above-described various embodiments may be arbitrarily combined without departing from the spirit of the invention.

  INDUSTRIAL APPLICABILITY The present disclosure is useful as an endoscope that can protect an imaging device from damage caused by static electricity while suppressing an increase in diameter with a simple structure.

DESCRIPTION OF SYMBOLS 11 Endoscope 13 Lens 15 Image sensor 17 Holder 19 Sheath 21 Metal cylinder part 23 Metal wire 25 Guide wire 27 Guide wire hole 37 Lighting optical fiber 43 Observation hole 47 Sheath fitting part 49 Cable 57 Sensor circuit part 65 Camera housing part

Claims (7)

A lens provided at the distal end in the insertion direction to the subject, to which imaging light is incident;
An imaging element provided at a rear end of the lens, where the imaging light is imaged;
A conductive member that covers the lens and the imaging element;
Grounding member for grounding the conductive member,
Endoscope. A guide wire lumen provided at the distal end in the insertion direction and having a guide wire hole through which the guide wire passes;
The endoscope according to claim 1. The conductive member also serves as the guide wire lumen having the guide wire hole,
The endoscope according to claim 2. The sensor circuit portion of the image sensor and the conductive member are disposed apart from each other,
The endoscope according to claim 1. The lens is arranged so that the imaging light forms an image on a light receiving surface of the imaging device,
An outer diameter of a cross-sectional shape of the lens in a direction orthogonal to the optical axis is larger than an outer diameter of a cross-sectional shape of the sensor circuit unit in a direction orthogonal to the optical axis,
The endoscope according to claim 4. The insulation resistance between the conductive member and the grounding member is smaller than the insulation resistance between the sensor circuit unit and the conductive member,
The endoscope according to claim 4. The grounding member is a metal wire,
The endoscope according to claim 6.

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