JP2014230638A - Endoscope and endoscope system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve fastness and assembly precision of an insertion part in a structure to seal an insertion part of an endoscope provided with an objective lens system and an image sensor.SOLUTION: An endoscope body 2 includes: an objective lens system 15; a lens holder 16 for supporting the objective lens system; an image sensor 17 provided behind the objective lens system; a signal cable 11 electrically connected to the image sensor that extends backward from the connection part with the image sensor; and a cover member 18 for covering the image sensor and the connection part with the image sensor. An adhesive agent is applied inside the cover member, and the front part of the cover member is fixed to the lens holder while the rear part of the cover member is fixed to the signal cable.

Description

  The present invention relates to an endoscope and an endoscope system for imaging 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. Moreover, such an insertion part requires sufficient sealing performance from the viewpoints of physical protection and ensuring water resistance during use and maintenance of the endoscope.

  As the sealing structure of the insertion portion of the endoscope, for example, in a state where the CCD module is inserted into the insulating tube located at the distal end of the insertion portion, and the cable for the CCD module is extended from the opening of the insulating tube, A configuration is known in which an opening of an insulating tube is sealed by pouring conductive resin into the insulating tube from a gap to form a conductive layer (see Patent Document 1).

Japanese Patent No. 3268008

  By the way, in endoscopes such as those described above, insertion portions having various outer diameters (for example, about 5 mm to 15 mm) are employed depending on the application. The diameter is being reduced (for example, the outer diameter should be 2 mm or less).

  However, as in the prior art described in Patent Document 1, in the method of pouring resin into a heat-shrinkable insulating tube at the distal end of the insertion portion of the endoscope and sealing the insertion portion, the diameter of the insertion portion is reduced. In some cases, it is difficult to stably ensure robustness and assembly accuracy.

  The present invention has been devised in view of such problems of the prior art, and improves the robustness and assembly accuracy of the insertion portion in the structure for sealing the insertion portion provided with the objective lens system and the image sensor. It is a main object of the present invention to provide an endoscope and an endoscope system that can be used.

  An endoscope according to the present invention is an endoscope provided with an insertion portion that is inserted into an observation target, and includes an objective lens system provided in the insertion portion and a lens holder that supports the objective lens system And an image sensor provided behind the objective lens system in the insertion portion, and electrically connected to the image sensor in the insertion portion and extending rearward from a connection portion with the image sensor. A signal cable and a cover member that covers the image sensor and the connection part, the inside of the cover member is filled with an adhesive, and the front portion of the cover member is fixed to the lens holder, The rear portion of the cover member is fixed to the signal cable.

  According to the present invention, in the structure for sealing the insertion portion provided with the objective lens system and the image sensor, there is an excellent effect that it is possible to improve the robustness and assembly accuracy of the insertion portion.

1 is an overall configuration diagram of an endoscope system according to an embodiment of the present invention. A perspective view of the front side of the distal end of the insertion portion in the endoscope body Rear perspective view of the distal end of the insertion section in the endoscope body Disassembled perspective view of the distal end of the insertion portion in the endoscope body Sectional view of the distal end of the insertion section in the endoscope body Front perspective view showing a state where the sensor cover at the distal end of the insertion portion is removed Rear perspective view showing a state in which the sensor cover at the distal end of the insertion portion is removed VIII-VIII sectional view in FIG. Explanatory drawing of bending operation at the distal end of the insertion section in the endoscope body

  A first invention made to solve the above-described problem is an endoscope provided with an insertion portion to be inserted into an observation target, the objective lens system provided in the insertion portion, and the objective A lens holder that supports the lens system, an image sensor provided behind the objective lens system in the insertion portion, and electrically connected to the image sensor in the insertion portion; and A signal cable extending rearward from the connection site; and a cover member covering the image sensor and the connection site; the cover member is filled with an adhesive; and a front portion of the cover member is attached to the lens holder On the other hand, the rear portion of the cover member is fixed to the signal cable.

  According to the endoscope according to the first invention, as a configuration for sealing the insertion portion provided with the objective lens system and the image sensor, the cover member that covers the connection portion of the image sensor and the signal sensor. Since the front and back parts of the cover member are fixed to the lens holder and the signal cable, respectively, the robustness and assembly accuracy of the insertion part can be improved.

  According to a second aspect, in the first aspect, the image sensor has a rectangular shape as viewed from the insertion direction of the insertion portion, and the cover member has the rectangular shape as viewed from the insertion direction of the insertion portion. An opening into which any one of the four corners of the image sensor is inserted is formed.

  According to the endoscope according to the second aspect of the present invention, by providing the cover member with the opening into which the corner portion of the image sensor is inserted, the cover member that covers the image sensor prevents the diameter of the insertion portion from being reduced. Thus, the robustness and assembly accuracy of the insertion portion can be improved.

  According to a third aspect, in the second aspect, the opening is formed above the cover member.

  According to the endoscope according to the third aspect of the present invention, when the adhesive is filled into the cover member, the cover member can be stably filled with the adhesive by using the opening as a vent. Thus, the robustness of the insertion portion can be further improved.

  According to a fourth invention, in the second or third invention, the adhesive is filled so as to close the opening.

  According to the endoscope according to the fourth aspect of the present invention, by using an adhesive that does not easily transmit light that can be detected by the image sensor (has translucency), light from the outside through the opening ( (Stray light) can be prevented from entering the light receiving surface of the image sensor, and the corner portion of the cover member can be securely fixed to improve the robustness and assembly accuracy of the insertion portion.

  According to a fifth aspect, in any one of the first to fourth aspects, the cover member is made of a non-translucent material, and the adhesive is made of a thermosetting resin. And

  According to the endoscope according to the fifth aspect of the invention, the cover member is made of a light-impermeable material, thereby preventing stray light from the outside from entering the light receiving surface of the image sensor through the cover member. In addition, the adhesive can be stably cured by heating, and the robustness and assembly accuracy of the insertion portion can be improved.

  According to a sixth aspect, in any one of the first to fifth aspects, an optical transmission member that transmits illumination light is inserted into the insertion portion, and the image sensor and the The light transmitting member is further provided with a non-translucent partition member, and the cover member is fixed to the partition member.

  According to the endoscope of the sixth aspect of the invention, the stray light from the light transmission member is incident on the light receiving surface of the image sensor by the non-transparent partition member disposed between the image sensor and the light transmission member. In addition to preventing this, the robustness of the insertion portion can be improved.

  In a seventh aspect based on the sixth aspect, the partition member extends rearward from the lens holder and has an upper surface on which the image sensor is placed. .

  According to the endoscope of the seventh aspect of the invention, stray light from the light transmission member is prevented from entering the light receiving surface of the image sensor, and the positioning of the image sensor is facilitated to improve the assembly accuracy of the insertion portion. be able to.

  An eighth invention is an endoscope system including the endoscope according to any one of the first to seventh inventions, and an image processing device that processes an image from the endoscope.

  Hereinafter, embodiments 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 FIG. 1 in principle. Here, “upper” and “lower” correspond to the upper and lower sides of the video processor 3 respectively, and “front (front)” and “rear” respectively correspond to the insertion portion 5 side and the plug portion 6 side of the endoscope body 2. Correspond.

  FIG. 1 is an overall configuration diagram of an endoscope according to an embodiment of the present invention, and FIGS. 2 and 3 are perspective views showing a front side and a rear side of a distal end of an insertion portion in an endoscope body, respectively.

  As shown in FIG. 1, an endoscope system 1 is obtained by photographing an endoscope main body (endoscope) 2 that is a medical flexible endoscope and an inside of an observation target (here, a human body). It is mainly composed of a video processor (image processing apparatus) 3 that performs known image processing and the like for still images and moving images. The endoscope main body 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 plug portion 6 of the endoscope main body 2 is inserted into the socket portion 7, whereby the endoscope main body 2 receives power and various signals (video signal, control signal, etc.) with the video processor 3. Sending and receiving is possible.

  The insertion portion 5 has a relatively small outer diameter (here, the maximum outer diameter is 1.8 mm), and a flexible cable portion (signal cable) 11 having a rear end connected to the plug portion 6. And an insertion portion distal end 12 connected to the distal end of the cable portion 11. The cable portion 11 has a generally circular cross section, and has a well-known configuration in which a plurality of electric wires made of a conductor covered with an insulator and a protective coating are bundled. And various signal transmission paths.

  As shown in FIG. 2, a lens holder 16 that supports a lens unit (objective lens system) 15, an image sensor 17 disposed behind the lens unit 15, the image sensor 17, and this A metal sensor cover (cover member) 18 that covers the tip of the cable part 11 connected to the cable is mainly provided. As shown in FIG. 3, the tip of the cable portion 11 that is electrically connected to the image sensor 17 is inserted into a substantially circular cable insertion hole 20 formed in the rear wall 19 of the sensor cover 18. As will be described in detail later, the inside of the sensor cover 18 is filled with an adhesive 21 for sealing. In addition, the term “adhesive” in this specification is not a strict meaning of a substance used for bonding a surface of a solid object, but a broad meaning of a substance that can be used for bonding two objects. Used in

  4 is an exploded perspective view of the distal end of the insertion section in the endoscope body, FIG. 5 is a cross-sectional view of the distal end of the insertion section in the endoscope body, and FIGS. 6 and 7 show the sensor cover at the distal end of the insertion section. FIG. 8 is a cross-sectional view taken along the line VIII-VIII in FIG. 2.

  As shown in FIG. 4, the lens holder 16 includes a holder main body portion 25 having a substantially cylindrical shape, a flange portion 26 provided so as to protrude in a radial direction from a peripheral edge of a front end portion of the holder main body portion 25, and a holder main body. It has a bottom wall part (partition member) 27 provided on the lower side so as to support the part 25, and these parts are integrally formed of a highly rigid material (metal, hard resin, etc.). .

  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. As shown in FIG. 5, in the lens unit 15, a plurality (here, three) of optical lenses L1 to L3 having the same diameter and made of an optical material (glass, resin, etc.) and a diaphragm member 32 are made of a metal cylinder. Are assembled in a close contact with each other in the axial direction. A cover glass 35 made of an optical material for protecting the lens unit 15 is provided in front of the lens frame 33. As shown in FIG. 4, the cover glass 35 has a substantially disk shape in which the top and bottom are linearly cut out, and is opened inside the flange portion 26 of the lens holder 16 to allow the imaging light to enter. It is inserted in.

  In the flange portion 26, two illumination windows 37 and 38 arranged in the left-right direction are formed below the imaging window 36. These illumination windows 37 and 38 transmit light transmitted from a light source (not shown) provided on the video processor 3 side via optical fibers (optical transmission members) 41 and 42 (see FIG. 7) to the front imaging part. It emits toward (not shown). Further, in the flange portion 26, adhesive pools 43 and 44 are formed on both the left and right sides of the illumination windows 37 and 38, respectively.

  In addition, two adjustment holes 51 and 52 arranged in the front-rear direction are formed in the upper portion of the holder main body 25, and one adjustment hole 53 is formed in the left side thereof. The adjustment holes 51 and 52 each have a substantially oval shape extending in the circumferential direction, and the adjustment hole 53 has a substantially oval shape extending in the axial direction. At the time of assembling the insertion portion 5, the operator can move the lens unit 15 in the front-rear direction through the adjustment holes 51 to 53 using a predetermined jig in order to adjust the fixing position of the lens unit 15. .

  The bottom wall portion 27 has an extending portion 61 that extends rearward from the rear end of the holder main body portion 25, and the extending portion 61 has a substantially flat upper surface 62. On the lower surface side of the bottom wall portion 27, a concave groove (see FIG. 7) 63 extending in the front-rear direction is formed. The front end of the groove 63 communicates with the illumination windows 37 and 38 of the flange portion 26, and the optical fibers 41 and 42 are inserted into the groove 63.

  A metal holder cover 65 is attached to the holder main body 25 of the lens 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 so as to shield at least the adjustment holes 51 to 53. 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 is connected to the rear surface of the flange portion 26 of the lens 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 66 of the holder main body portion 25. It is located forward (see FIG. 6). Further, the left and right lower edges of the holder cover 65 are connected to the left and right edges of the bottom wall portion 27, respectively.

  The image sensor 17 is composed of a small CCD (here, one side is 1 mm in size) having a substantially rectangular shape when viewed from the front-rear direction (insertion direction of the insertion portion 5). The image sensor 17 is fixed to the rear portion 66 of the holder main body 25 while being placed on the upper surface 62 of the extending portion 61 in the lens holder 16. As shown in FIG. 5, a through hole 71 communicating with the lens mounting hole 31 is formed in the rear portion 66 of the lens holder 16, and light from the lens L <b> 3 is received by the image sensor 17 through the through hole 71. Incident on the surface. 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. In addition, the tip 73 of the cable portion 11 is electrically connected to the rear portion (back side) of the circuit board 72 by soldering.

  Since the image sensor 17 is mounted on the upper surface 62 of the extending portion 61 of the lens holder 16 at the distal end 12 of the insertion portion, the image sensor 17 and the optical fibers 41 and 42 are opaque (here, It is partitioned off by a bottom wall portion 27 made of metal. As a result, even when unnecessary light (stray light) is emitted from the outer peripheral surfaces of the optical fibers 41 and 42 that pass around the image sensor 17 (downward here), the stray light is incident on the light receiving surface of the image sensor 17. Incident light can be prevented. Further, by placing the image sensor 17 on the upper surface 62 of the extending portion 61, the alignment between the image sensor 17 and the lens unit 15 is facilitated, and the optical assembly accuracy at the distal end 12 of the insertion portion can be improved. it can.

  As shown in FIG. 4, the sensor cover 18 has a shape in which the lower part of the cylinder is flat so as to form a substantially D shape when viewed from the front and rear direction. The sensor cover 18 has a cylindrical wall 81 positioned on the upper side and a lower side. It has a flat bottom wall 82 located. Two cutouts (openings) 83 and 84 opened from the front end are formed in the cylindrical wall 81 of the sensor cover 18, and a cutout 85 opened from the front end is formed in the lower wall 82. Has been. The notches 83 and 84 have a substantially rectangular shape, and are arranged at positions corresponding to the left and right corners 91 and 92 located above the image sensor 17, respectively. The cutout portion 85 has a substantially rectangular shape as in the outer shape of the extension portion 61 of the lens holder 16 in a plan view, and has the same size (or slightly larger size) as the extension portion 61.

  In assembling the insertion portion distal end 12, first, after the lower surface of the image sensor 17 is bonded to the upper surface of the extension portion 61 in the lens holder 16, the lens unit 15, the cover glass 35, and the holder cover are attached to the lens holder 16. 65 is glued. At this time, the front surface of the image sensor 17 is in contact with the rear surface of the holder main body 25 as shown in FIG. Thereafter, as shown in FIGS. 6 and 7, the image sensor 17, the circuit board 72, and the distal end of the cable unit 11 (electrically connected to the image sensor 17) are located behind the rear part 66 of the holder main body part 25 in the lens holder 16. Adhesive 21 is applied so as to cover 73).

  Thereafter, the sensor cover 18 is fitted into the rear part of the lens holder 16. At this time, the adhesive 21 is filled in the sensor cover 18. Further, the inner peripheral surface of the front end portion of the cylindrical wall 81 in the sensor cover 18 is bonded to the outer peripheral surface of the rear portion 66 of the holder main body portion 25. Further, the sensor cover 18 is bonded to the cutout portion 85 of the lower wall 82 in a state in which the extending portion 61 of the lens holder 16 is fitted. Further, the cable portion 11 is inserted into the cable insertion hole 20 of the sensor cover 18, and the inner peripheral surface of the cable insertion hole 20 and the outer peripheral surface of the cable portion are bonded.

  Such adhesion between the sensor cover 18 and the lens holder 16 is performed using an adhesive 21 filled in the sensor cover 18, and the adhesive 21 is used depending on the material of the sensor cover 18 and the lens holder 16. Different adhesives may be used. The same applies to the adhesive used for bonding the inner peripheral surface of the cable insertion hole 20 and the outer peripheral surface of the cable portion.

  When the adhesive 21 is filled, the notches 83 and 84 and the cable insertion hole 20 (see FIG. 3) function as vents, so that the sensor cover 18 can be filled with the adhesive 21 stably. Become. Moreover, when surplus occurs in the adhesive 21 to be filled, it leaks from the gaps between the notches 83 and 84 and the cable insertion hole 20 (see FIG. 3), but the leaked adhesive is appropriately removed. . The adhesive 21 is filled so as to have a waterproof performance to such an extent that the adhesive 21 will not be submerged even if submerged temporarily.

  As the adhesive 21, various known adhesives can be used, but an adhesive made of a thermosetting resin such as an epoxy resin system or an acrylic resin system may be used. This makes it possible to use a light-impermeable material for the sensor cover 18, preventing stray light from the outside from entering the light receiving surface of the image sensor 17 through the sensor cover 18 and heating the adhesive. Can be cured stably to improve the robustness and assembly accuracy of the insertion portion.

  When the assembly of the insertion portion distal end 12 is completed, as shown in FIG. 8, the left and right corner portions 91 and 92 located on the upper side of the image sensor 17 are respectively inserted into the cutout portions 83 and 84 of the sensor cover 18. It becomes. In this case, the corners 91 and 92 are located at least inside the outer shape (outer peripheral surface) of the sensor cover 18. The notches 83 and 84 are filled with an adhesive 21 so as to close the notches 83 and 84. With such a configuration, there is an advantage that the diameter of the insertion portion distal end 12 is not hindered by the sensor cover 18 that covers the image sensor 17.

  Here, the configuration in which the two corners 91 and 92 located on the upper side are inserted into the notches 83 and 84 of the image sensor 17 is shown, but the number and positions of the corners to be inserted are variously changed. Is possible. For example, like the upper corners 91 and 92, the left and right corners positioned below the image sensor 17 may be inserted into notches (openings) formed below the sensor cover 18.

  The adhesive 21 is filled in the notches 83 and 84 into which the corners 91 and 92 of the image sensor 17 are inserted. By using the adhesive 21 that does not easily transmit light (for example, visible light, infrared light, etc.) that can be detected by the image sensor 17 (has translucency), the adhesive 21 is externally provided through the notches 83 and 84. Light (stray light) can be prevented from entering the light receiving surface of the image sensor, and the corner portions 91 and 92 of the sensor cover 18 can be securely fixed to improve the robustness and assembly accuracy of the insertion portion distal end 12. it can.

  As described above, in the endoscope system 1, in the insertion portion 5, the adhesive is filled in the sensor cover 18 that covers the image sensor 17 and the tip 73 of the cable portion 11 that is electrically connected to the image sensor, Since the front and rear portions of the sensor cover 18 are fixed to the lens holder 16 and the cable portion 11, respectively, the robustness of the insertion portion distal end 12 is improved and the assembly accuracy of the optical system such as the image sensor 17 is improved. There is an advantage.

  FIG. 9 is an explanatory view of the bending operation of the distal end of the insertion portion in the endoscope body. The cable part 11 of the endoscope body 2 can be bent at an arbitrary position. As shown in FIG. 9, the endoscope main body 2 can be inserted into an observation target (such as a human body) while freely changing the angle of the distal end of the insertion portion 5 in the same manner as a conventional flexible endoscope. In this case, the insertion portion distal end 12 is displaced following the bending operation of the cable portion 11, but peeling or cracking does not occur in the adhesive 21 in the sensor cover 18, and the sealing performance is not deteriorated. The bending operation of the cable portion 11 hardly affects the distal end 12 of the insertion portion, and the robustness and assembly accuracy of the insertion portion 5 are well maintained.

  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 of the endoscope according to the present invention is not limited to the use as a flexible endoscope, and can also be used as a rigid endoscope. In addition, the filling of the adhesive into the sensor cover does not necessarily have to be performed so as to fill the entire inner space of the sensor cover, and at least the sealing performance (robustness etc.) at the distal end of the insertion portion can be ensured. Good. Moreover, you may use several types of adhesives as an adhesive agent with which it fills in a sensor cover. In addition, the material for forming the sensor cover is not limited to metal, and other materials (resin etc.) can be used as long as necessary rigidity can be ensured. It should be noted that not all the constituent elements of the endoscope and the endoscope system according to the present invention shown in the above embodiments are necessarily essential, and can be appropriately selected as long as they do not depart from the scope of the present invention. It is.

  An endoscope and an endoscope system according to the present invention can improve the robustness and assembly accuracy of an insertion portion in a structure for sealing an insertion portion provided with an objective lens system and an image sensor, and can be externally applied. It is useful as an endoscope and an endoscope system for imaging the inside of an observation object that cannot be directly observed.

1 Endoscope system 2 Endoscope body (endoscope)
3 Video processor (image processing device)
5 Insertion part 6 Plug part 7 Socket part 11 Cable part (signal cable)
12 Insertion section tip 15 Lens unit (objective lens system)
16 Lens holder 17 Image sensor 18 Sensor cover (cover member)
21 Adhesive 25 Holder body part 26 Flange part 27 Bottom wall part (partition member)
36 Imaging window 37, 38 Illumination window 41, 42 Optical fiber (optical transmission member)
61 Extension part 62 Upper surface 83, 84 Notch part (opening part)
91, 92 corners

Claims (8)

An endoscope provided with an insertion portion to be inserted inside an observation target,
An objective lens system provided in the insertion portion;
A lens holder for supporting the objective lens system;
An image sensor provided behind the objective lens system in the insertion portion;
A signal cable that is electrically connected to the image sensor at the insertion portion and extends rearward from a connection site with the image sensor;
A cover member that covers the image sensor and the connection part;
The cover member is filled with an adhesive,
An endoscope, wherein a front portion of the cover member is fixed to the lens holder, and a rear portion of the cover member is fixed to the signal cable. The image sensor has a rectangular shape when viewed from the insertion direction of the insertion portion,
The endoscope according to claim 1, wherein the cover member is formed with an opening into which one of four corners of the image sensor is inserted when viewed from the insertion direction of the insertion portion. .   The endoscope according to claim 2, wherein the opening is formed above the cover member.   The endoscope according to claim 2 or 3, wherein the adhesive is filled so as to close the opening. The cover member is formed from an opaque material,
The endoscope according to any one of claims 1 to 4, wherein the adhesive is made of a thermosetting resin. An optical transmission member that transmits illumination light is inserted through the insertion portion,
A translucent partition member disposed between the image sensor and the light transmission member in the insertion portion;
The endoscope according to any one of claims 1 to 5, wherein the cover member is fixed to the partition member.   The endoscope according to claim 6, wherein the partition member extends rearward from the lens holder and has an upper surface on which the image sensor is placed.   An endoscope system comprising: the endoscope according to any one of claims 1 to 7; and an image processing device that processes an image from the endoscope.

Images