JP2011200338A - Electronic endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To retain the electric characteristics and durability of an electronic endoscope by a simple structure and at a low cost.SOLUTION: A flexible board 37 whose one end is connected to a CCD 27 is bent in an S shape, and the other end of the flexible board is in close contact with the inner wall surface of a protection frame 41 formed of a metal plate with high thermal conductivity. The protection frame 41 is composed of a U-shaped part 41a and a spring part 41b. The U-shaped part 41a covers the flexible board 37 for protection. Only by inserting the protection frame 41 into the inner side of a cylinder part 32a of a joint ring 32, both edges on the distal end side of the spring part 41b are securely brought into elastic contact with the inner surface of the cylinder part 32a. Heat generated from the CCD 27 and the flexible board 37 is conducted to the U-shaped part 41a, and to the joint ring 32 from the spring part 41a. The joint ring 32 is connected with a plurality of joint rings 33, and the heat generated from the CCD 27 and the flexible board 37 is conducted to the plurality of joint rings 33 from the protection frame 41 and the joint ring 32, and so that the heat is efficiently radiated.

Description

  The present invention relates to an electronic endoscope provided with a solid-state imaging device at the distal end of an insertion portion.

  The electronic endoscope has an insertion portion that is inserted into a subject and an operation portion that is connected to the insertion portion. The insertion portion has a distal end portion, a bending portion, and a flexible tube portion in order from the distal end. The distal end portion is provided with an observation window, an illumination window, a forceps outlet, an air / water supply port, and the like. The bending portion is provided with a plurality of joint nodes (hereinafter referred to simply as “nodes”) connected to each other, and the angle knob provided on the operation unit can be rotated and operated in any of the vertical and horizontal directions. Bend. Thereby, the insertion property into the subject can be made smooth, and the tip can be directed in a desired direction within the subject.

  An imaging device for imaging the inside of the subject through the observation window is built in the distal end portion. The imaging device includes an imaging lens disposed behind the observation window, a solid-state imaging device disposed behind the imaging lens, and a solid-state imaging device that is electrically connected to the solid-state imaging device driving circuit and the solid-state imaging device. The circuit board includes a preamplifier for amplifying the output signal, and a signal cable that is fixed to the terminal of the circuit board with solder and electrically connects the circuit board to the image processing apparatus or the like. This signal cable is arranged in the insertion portion together with an angle wire for bending the bending portion, a light guide (optical fiber) for guiding the illumination light from the light source device to the illumination window, and the like.

  In recent years, the diameter of the insertion portion has been reduced in order to reduce the pain of the subject. For example, in an endoscope imaging apparatus described in Patent Document 1, a flexible substrate is directly attached to a solid-state imaging device, a flexible substrate protruding from the outer shape of the solid-state imaging device is bent toward the outer center of the solid-state imaging device, and a circuit is connected thereto. By connecting at least one of the substrate and the signal cable, the connection portion between the circuit board or the signal cable and the solid-state imaging device is miniaturized.

  In the electronic endoscope described in Patent Document 2, a part of the node ring closest to the tip is extended to the tip to form a flat portion, and a solid-state imaging device, an IC chip, and the like are disposed on the flat portion. As a result, the tip portion is reduced in diameter and size, and a node ring having good conductivity is used as a heat radiating member for the solid-state imaging device or IC chip, thereby suppressing the temperature rise of the solid-state imaging device or IC chip.

JP 2000-83896 A JP-A-63-226615

  As described in Patent Documents 1 and 2, the diameter of the insertion portion is rapidly reduced. Along with this, various problems have arisen. For example, if the solid-state imaging device is downsized, the area of the light receiving unit is reduced. Therefore, unless the light amount of a light source (such as an LED) that illuminates the body cavity is increased, the brightness of the image obtained from the solid-state imaging device is reduced. When the amount of light from the light source is increased, the temperature of the optical fiber that guides the light from the light source to the distal end of the endoscope rises, and the temperature of the solid-state imaging device and circuit board provided in the vicinity of the optical fiber also rises. As a result, the dark current level rises and the problem of deterioration of electrical characteristics such as noise on the output signal from the solid-state imaging device occurs. In addition, due to the temperature rise of the solid-state imaging device and the circuit board, there arises a problem that the durability of these electronic components is reduced (the timing of electrical property deterioration and physical breakage is advanced).

  In order to suppress the temperature rise of the solid-state imaging device and the circuit board, as described in Patent Document 2, a part of the node ring located at the position closest to the tip portion is extended to the tip portion side to form a plane portion. Although it is conceivable to arrange a solid-state imaging device, an IC chip, etc., a node ring having a shape that is significantly different from the conventional one is used, so that there is a disadvantage that the manufacturing cost of the electronic endoscope is greatly increased. .

  In addition, the tip of the insertion part is sprayed with water for cleaning not only an optical fiber and a solid-state image sensor that propagates illumination light from the light source, but also forceps for collecting the tissue of the affected part and an observation window of the solid-state image sensor. Since the tubes and the like for spraying are concentrated, the inside of the distal end portion becomes increasingly denser as the diameter of the insertion portion is reduced. As a result, there arises a problem of structural durability deterioration that the durability of the circuit board and the cable connecting portion is lowered.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an electronic endoscope that satisfies both electrical property maintenance and durability maintenance at the same time with a simple configuration and low cost.

  The electronic endoscope of the present invention has a built-in solid-state imaging device that converts an optical image into an image signal, is connected to the distal end portion of the insertion portion that is inserted into the subject, and the distal end portion, and is rotatably and serially connected. An electronic endoscope having a bending portion configured to bendable by incorporating a plurality of articulated joint rings coupled to the solid-state imaging device, and electrically connected to the solid-state imaging device; A flexible substrate provided with a circuit or the like for driving, and a U-shaped portion in which the flexible substrate is covered and protected in a U-shape and at least a part of the flexible substrate is in close contact with a part of the inner wall surface; A protective frame having a thermal conductivity is provided, which is provided integrally with the U-shaped portion and includes a spring portion that is elastically contacted with the joint node ring.

  It is preferable that a pair of slits be formed at the end of the spring portion that is in elastic contact with the joint node ring. It is preferable to fill the inside of the U-shaped portion with a resin having thermal conductivity.

  According to the present invention, the protective frame having thermal conductivity that is elastically brought into contact with the joint joint ring is provided while protecting the flexible substrate in a U-shape, so that the electronic circuit can be realized with a simple configuration and at low cost. It is possible to simultaneously maintain the electrical characteristics and durability of the endoscope. In addition, when a pair of slits are formed at the end of the spring portion that is elastically contacted with the joint node ring, the number of portions that are elastically contacted with the joint node ring is increased, so that heat generated from the solid-state imaging device or the flexible substrate is increased. Can be radiated to the joint joint ring more efficiently. In addition, if a resin having thermal conductivity is filled inside the U-shaped portion, the flexible substrate can be more firmly protected and the thermal conductivity to the joint joint ring can be further increased.

1 is an external view of an endoscope system according to an electronic endoscope of the present invention. It is sectional drawing which looked at the inside of the front-end | tip part and the inside of a part of curved part from the side surface. It is a perspective view which shows an example of a protective frame. It is explanatory drawing which shows a mode that the spring part of the protection frame shown in FIG. 3 is elastically contacting with the internal peripheral surface of the cylindrical part of a node ring. It is a perspective view which shows the example of another protection frame. It is explanatory drawing which shows a mode that the spring part of the protection frame shown in FIG. 5 is elastically contacting with the internal peripheral surface of the cylindrical part of a node ring. It is sectional drawing which shows the example which filled resin inside the U-shaped part of the protective frame.

  As shown in FIG. 1, the endoscope system 2 includes an electronic endoscope 10, a processor device 11, a light source device 12, and the like. The electronic endoscope 10 includes an insertion portion 13 to be inserted into a subject, an operation portion 14 connected to a proximal end portion of the insertion portion 13, and a universal cord 15 connected to the processor device 11 and the light source device 12. And.

  A connector 16 is attached to the tip of the universal cord 15. The connector 16 is a composite type connector to which the processor device 11 and the light source device 12 are connected. The light source device 12 generates light with higher brightness than before in order to compensate for the decrease in the brightness of the image obtained from the CCD 27 due to the reduction in the area of the imaging surface 27a accompanying the downsizing of the CCD 27 (see FIG. 2) described later. Built-in light source.

  The processor device 11 performs various kinds of image processing on the imaging signal input from the CCD 27 (see FIG. 2), which is a solid-state imaging device for in-subject imaging, through the universal code 15 and the connector 16, and converts the imaging signal into a video signal. At the same time, a drive control signal for controlling the drive of the CCD 27 is transmitted. The video signal converted by the processor device 11 is displayed as an endoscopic image on a monitor 17 connected to the processor device 11 by a cable. Further, the processor device 11 is electrically connected to the light source device 12 and comprehensively controls the operation of the entire endoscope system 2.

  The insertion portion 13 includes a distal end portion 13a, a bending portion 13b, and a flexible tube portion 13c in order from the distal end. The front end portion 13a is made of a resin, but the inside thereof is formed of a hard metal material or the like, and the CCD 27 or the like is built therein. The bending portion 13b is configured by connecting a plurality of joint nodes (hereinafter simply referred to as a node ring) 33 (see FIG. 2), and is inserted into the flexible tube portion 13c by operating the angle knob 18. It bends vertically and horizontally in conjunction with the movement of an angle wire (not shown). As a result, the distal end portion 13a is directed in a desired direction in the body cavity, and the site to be observed in the body cavity can be imaged by the CCD 27. The flexible tube portion 13c is a portion that connects the operation portion 14 and the bending portion 13b in a long shape with a small diameter, and has flexibility.

  In FIG. 2, an observation window 21, an illumination window (not shown), a forceps outlet 22, and an air / water supply nozzle 23 are provided on the end surface of the distal end portion 13 a. In the back of the observation window 21, an objective optical system 24 (imaging lens) for capturing image light in the body cavity is disposed in the lens barrel 25. The image light of the observation site via the objective optical system 24 is incident on the prism 26 and bent inside the prism 26 to form an image on the imaging surface 27 a of the CCD 27. A CMOS image sensor may be provided instead of the CCD 27.

  The exit end of the light guide 28 faces the illumination window. The light guide 28 is formed by bundling a large number of optical fibers (for example, made of quartz). The light guide 28 passes through the insertion portion 13, the operation portion 14, the universal cord 15, and the connector 16. When the connector 16 is connected to the light source device 12, the illumination guide emits illumination light emitted from the light source device 12. To the site to be observed in the body cavity.

  The air / water supply nozzle 23 is supplied from an air / water supply device (not shown) built in the light source device 12 by operating an air / water supply button 19 (see FIG. 1) provided in the operation unit 14. The air and the cleaning water are sprayed onto the observation window 21. In the forceps outlet 22, various treatment tools for performing a treatment on the site to be observed are inserted from the forceps opening 20 (see FIG. 1) provided in the operation unit 14.

  The front end portion 29 of the distal end portion 13a is made of a hard resin and the circumferential skin 30 is made of a soft resin. Inside the circumferential skin 30, a cylindrical portion 31 made of a hard metal material has one end at the front end. 29 is provided to be joined. When connecting the assembled tip portion 13a to the curved portion 13b, a metal node ring 32 having a high thermal conductivity and disposed on the inner wall surface of the other end portion of the cylindrical portion 31 closest to the tip portion 13a. The outer peripheral surface of the cylindrical portion 32a is fixed.

  The node ring 32 is formed with a pair of outer link portions 32b protruding in the axial direction from one end edge, and the inner link of the metal node ring 33 having a high thermal conductivity and a shape different from that of the node ring 32. The part 33c is connected. A plurality of the node rings 33 are provided in series in the bending portion 13b. Since the node rings 32 and 33 can be used as they are without any change in the configuration thereof, the manufacturing cost of the electronic endoscope 10 is not increased.

  The node ring 33 includes a cylindrical portion 33a, a pair of outer link portions 33b protruding in the axial direction from one end edge of the cylindrical portion 33a, and a pair of inner link portions 33c protruding in the axial direction from the other end edge. Consists of. The outer link portion 33b and the inner link portion 33c are arranged 90 degrees apart in the circumferential direction of the cylindrical portion 33a, and a connection hole 34 is formed in each. Adjacent node rings 33 are rotatably connected to the connection holes 34 through coupling pins with the outer link portion 33b and the inner link portion 33c overlapped. A pair of operation wires (not shown) for operating in the vertical and horizontal directions are provided in each of the node rings 32 and 33. By pushing and pulling each operation wire by operating the angle knob 18, the node rings 32 and 33 are provided. Rotating each other, the entire bending portion 13b is bent.

  The CCD 27 is composed of, for example, an interline type CCD, and a bare chip having an imaging surface 27a provided on the surface is used. A small CCD 27 is used to reduce the size of the distal end portion 13a as the diameter of the insertion portion 13 is reduced. For this reason, the area of the imaging surface 27a is also smaller than the conventional one. On the imaging surface 27a, a rectangular plate-like cover glass 36 is attached via a square frame-like spacer 35.

  One end portion of the flexible substrate 37 is electrically connected to the peripheral edge portion on the rear end side of the CCD 27 via bumps 38 by, for example, a flip chip method. Then, the CCD 27 and the flexible substrate 37 are bonded in a reinforcing manner with an adhesive 39 so that they are not easily peeled off. The flexible substrate 37 is provided with a circuit for driving the CCD 27 and a circuit such as an amplifier for amplifying the video signal output from the CCD 27.

  The flexible substrate 37 is bent in an S shape, and the other end is in close contact with the inner wall surface of the protective frame 41. The protective frame 41 is formed of a metal plate having a high thermal conductivity, for example, a copper plate. As shown in FIG. 3, the U-shaped portion 41a and the U-shaped portion 41a formed in a U-shape. And a spring portion 41b provided continuously with the spring.

  Since the U-shaped portion 41a covers and protects the flexible substrate 37 bent in an S shape, the durability of the connection portion between the flexible substrate 37 and signal cables 45 and 46 described later is reduced. The problem of structural durability degradation does not occur.

  Since the spring part 41b is bent in a shape like a hairpin curve when viewed from the side, the spring part 41b is simply inserted into the cylindrical part 32a of the node ring 32 by inserting the protective frame 41 of the assembled tip part 13a. As shown in FIG. 4, both edge portions on the tip end side of 41b are surely brought into elastic contact with the inner peripheral surface of the cylindrical portion 32a. Thereby, the heat generated from the CCD 27 and the flexible substrate 37 is transmitted to the U-shaped portion 41 a of the protective frame 41 and is transmitted from the spring portion 41 b to the node ring 32.

  Returning to FIG. 2, since the node ring 32 is connected to the plurality of node rings 33, the heat generated from the CCD 27 and the flexible substrate 37 passes through the protective frame 41 and the node ring 32 and the plurality of node rings 33. The heat is efficiently dissipated by these. As a result, the CCD 27 and the flexible substrate 37 are cooled, and the temperature rise of the CCD 27 and the flexible substrate 37 and the temperature rise inside the tip portion 13a can be prevented.

  As described above, since the light source device 12 employs a high-intensity light source, the amount of heat generated by the light guide that conducts light from the light source also increases. However, the temperature inside the tip portion 13a that rises due to the heat generated by the light guide is transmitted to the plurality of node rings 33 via the protective frame 41 and the node ring 32, and is efficiently radiated, so the temperature inside the tip portion 13a is The amount of heat generated from the CCD 27 and the flexible substrate 37 is not increased by heat from the light guide, and the dark current level is increased and noise is added to the video signal output from the CCD 27. There is no problem of characteristic deterioration.

  In addition, when the number of frames of the CCD 27 is increased in order to improve the image quality, the amount of heat generated by the CCD 27 increases. However, since the heat is efficiently radiated by the plurality of node rings 33 via the protective frame 41 and the node ring 32, It is possible to prevent the temperature inside the tip portion 13a from rising. As a result, the dark current level rises due to the temperature rise inside the tip portion 13a, the electrical characteristics decline such as noise on the video signal output from the CCD 27, and the durability of each electronic component due to the temperature rise inside the tip portion 13a. However, there is no problem of deterioration in durability, such as deterioration of electrical properties (deterioration of electrical characteristics and advancement of physical damage).

  A plurality of terminals are provided on one surface on the other end side of the flexible substrate 37. Of these, for example, the signal wires 45 and 46 of the signal cables 45 and 46 are connected to the terminals 43 and 44 by soldering, respectively. (Connection part). The terminals 43 and 44 are, for example, input / output terminals or ground terminals. The signal cables 45 and 46 are arranged along the direction (axial direction) of the tube axis of the insertion portion 13 and are drawn out from the multicore cable 47.

  The protective frame is not limited to that described in the above embodiment, and may be a protective frame 50 as shown in FIG. In this protective frame 50, the U-shaped portion 50a has the same shape as the U-shaped portion 41a of the protective frame 41, but the spring portion 50b has a pair of slits 51 formed in the longitudinal direction, and the central portion. 52 and left and right end portions 53 and 54. As a result, when the protective frame 50 is inserted inside the cylindrical portion 32a of the node ring 32, both edge portions on the front end side of the left and right end portions 53 and 54 are formed on the inner peripheral surface of the cylindrical portion 32a as shown in FIG. Simultaneously with the elastic contact, both edge portions on the tip side of the central portion 52 are elastically contacted with the inner peripheral surface of the cylindrical portion 32a. As a result, the contact area between the spring part 50b of the protective frame 50 and the node ring 32 increases, and the thermal conductivity becomes higher.

  Further, as shown in FIG. 7, a resin 55 having high thermal conductivity may be filled inside the U-shaped portion 41 a of the protective frame 41. In this way, the protection of the flexible substrate 37 and the protection of the connection portion with the signal cables 45 and 46 become stronger. For example, even if a force such as pulling of the signal cables 45 and 46 is applied, no load is applied between the terminals 43 and 44 and the signal cables 45 and 46, or even a small amount is applied. From this, it is possible to prevent the soldered portions between the terminals 43 and 44 and the signal lines of the signal cables 45 and 46 from being peeled off. Further, the heat generated from the CCD 27 and the flexible substrate 37 is more efficiently conducted to the protective frame 41 by the resin 55 having high thermal conductivity, and the CCD 27 and the flexible substrate 37 can be cooled more efficiently. In addition, as resin 55 with high heat conductivity, what knead | mixed oxide fillers, such as an alumina resin and an alumina, for example is used.

  In the embodiment described above, the other end portion of the flexible substrate is in close contact with the inner wall surface of the protective frame. However, the flexible substrate may be joined in addition to being in close contact.

  In the above embodiment, one end portion of the flexible substrate is electrically connected to the edge portion on the rear end side of the CCD. However, the present invention is not limited to this, for example, the flexible substrate has a rectangular shape. A flexible substrate is disposed so that the imaging surface of the CCD is exposed from the window, and the edge of at least one of the four sides of the window is electrically connected to the CCD. It may be. In this case, it is preferable that the outer peripheral part of the imaging surface of the CCD and the edge part of each side of the window are reinforced with an adhesive.

2 Endoscope System 10 Electronic Endoscope 13 Insertion Part 13a Tip Part 13b Bending Part 27 CCD
32, 33 Node ring 32a, 33a Cylindrical part 37 Flexible substrate 41, 50 Protective frame 41a, 50a U-shaped part 41b, 50b Spring part 55 Resin

Claims (3)

A solid-state imaging device that converts an optical image into an image signal is built-in, and a distal end of an insertion portion that is inserted into a subject, and a plurality of joints that are continuously connected to the distal end and are connected in series freely. In an electronic endoscope having a bending portion configured to be freely bent by incorporating a node ring,
A flexible substrate electrically connected to the solid-state imaging device and provided with a circuit or the like for driving the solid-state imaging device;
A U-shaped portion that covers and protects the flexible substrate in a U-shape and at least a part of the flexible substrate is in close contact with a part of the inner wall surface, and is integrally connected to the U-shaped portion, An electronic endoscope comprising: a protective frame having thermal conductivity formed by a spring portion that is elastically contacted with the joint joint ring.   The electronic endoscope according to claim 1, wherein a pair of slits are formed at an end of the spring portion that is elastically contacted with the joint joint ring.   3. The electronic endoscope according to claim 1, wherein a resin having thermal conductivity is filled inside the U-shaped portion.

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