JP2010005148A - Endoscope and method of signal transmission of endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To take a measure against noise in transmitting signals by an imaging element inside a long insertion part. <P>SOLUTION: A CCD 43 is mounted at the distal end of the insertion part. Horizontal drive pulses ϕH1, ϕH2 and a reset pulse ϕRS in which high-frequency signals among the input/output signals of the CCD 43 flow are transmitted through optical fibers within the insertion part. An imaging signal Vout with a very weak electric current is also transmitted through the optical fibers within the insertion part. These optical fibers are mounted on a flexible optical wiring board 40. The flexible optical wiring board 40 is spirally wound inside the insertion part. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention provides an endoscope in which a cable for inputting / outputting a signal, a power source and the like to an image pickup device such as a CCD or a CMOS incorporated in a distal end portion of an insertion portion to be inserted into a body, and The present invention relates to an endoscope signal transmission method.

  An insertion portion to be inserted into the body is attached to the hand operation portion of the endoscope. The insertion portion has a configuration in which the distal end hard portion, the bending portion, and the flexible tube portion are connected in order from the distal end. The distal end hard portion is provided with an objective lens, an illumination lens, a forceps outlet, an air supply / water supply port, and the like on the distal end surface. An imaging element is built in the eyelid of the objective lens. The tip hard portion is formed of a hard metal material or the like. Further, the flexible tube portion is a portion that connects the hand operating portion and the bending portion in a thin shape with a small diameter, and has flexibility. The bending portion is bent in any direction, up, down, left, or right by pulling the angle wire by rotating the operation knob provided in the hand operation portion. Thereby, the insertion property to the patient can be made smooth, and the distal end hard portion can be directed in a desired direction in the body cavity.

  The endoscope is connected to the processor device by a unibar connector provided in the hand operation unit. The processor device includes a power supply circuit, an image sensor driver (drive circuit), a CDS circuit, an A / D converter, an image processing unit, and the like, and controls an image sensor to drive an image signal obtained from the image sensor. Digitally processed and displayed on an externally connected monitor.

  The insertion section incorporates a flexible multi-core cable for connecting between the image sensor and each circuit of the processor. The input / output signals include the power supply voltage VDD, the ground voltage VSS, the imaging signal Vout, the horizontal drive pulses φH1 and φH2, the vertical drive pulses φV1 to φV4, the reset pulse φRS, and the like. Since the electric wire of the multicore cable passes through the long insertion portion and is connected to the processor device from the hand operating portion via the universal connector, the total length becomes very long. If the wire is in a long state, for example, an imaging signal whose current is weaker than other signals is likely to be affected by ambient noise, and the SN ratio may be deteriorated. If this happens, the quality of the image displayed on the monitor will deteriorate.

Therefore, instead of a multi-core cable, a flexible printed circuit board is formed in a long band and provided inside the insertion portion, and a CDS circuit, an A / D converter, and an image are provided at predetermined intervals in the longitudinal direction of the circuit board. An endoscope has been proposed in which all or some of the electronic components of a video circuit configured by a processing unit are mounted and the electrical connection between the image sensor and the video circuit is shortened (Patent Document 1). .
JP 62-113121 A

  In the invention described in Patent Document 1, since the electronic component is mounted on the flexible printed board, the diameter of the insertion portion may be increased.

  In addition to the output image signal, signals such as a vertical drive pulse, a horizontal drive pulse, and a reset pulse are input to the image sensor. Signals such as a horizontal drive pulse and a reset pulse are signals having a higher frequency than other signals. In recent years, the number of pixels of an image sensor has been increased, and the frequency of a horizontal drive pulse signal has been increased. For this reason, when the horizontal drive signal is transmitted on the signal line, harmonic radiation (unnecessary radiation) having an integral multiple of the frequency is generated. The level of this unnecessary radiation becomes high at a specific frequency of 3 times, 5 times,... Of the horizontal drive pulse. Thus, when the level of unnecessary radiation becomes high, there is a possibility that noise is mixed in other signals. In particular, when noise is applied to the imaging signal, the quality of the image displayed on the monitor is degraded.

  The present invention has been made in view of such circumstances, and has taken measures to receive noise or to give noise to a signal line built in the insertion portion while preventing the insertion portion from increasing in diameter. An object is to provide an endoscope.

  In order to achieve the above object, in the endoscope of the present invention, the imaging element among the input / output signals transmitted through the insertion section to the imaging element provided in the distal end of the insertion section inserted into the body. An optical fiber is provided that transmits either or both of the horizontal drive pulse (ΦH1, ΦH2) signal, the reset pulse (ΦRS) signal, and the imaging signal (Vout) output from the imaging device. May be. In this case, other signals may be transmitted using an electric wire or a cable in which a plurality of electric wires are combined.

  Horizontal drive pulse (ΦH1, ΦH2) and reset pulse (ΦRS) signals are transmitted as high frequency signals from the drive circuit built in the processor device to which the endoscope is connected to the image sensor through the universal connector and the insertion unit. Entered. The imaging signal (Vout) is output as a signal with a weak current from the imaging device to the processor device through the insertion unit and the universal connector. For this reason, any one or both of the horizontal drive pulse (ΦH1, ΦH2), the reset pulse (ΦRS), and the imaging signal may be transmitted through the optical fiber.

  As an optical fiber for optical transmission, it is preferable that the optical fiber is mounted side by side on a flexible optical wiring board from the viewpoint of effective use of the space in the insertion portion. Further, electric wires for transmitting other signals may be arranged in a plane together with optical fibers for signal transmission and attached to the flexible optical wiring board. Furthermore, the optical fiber for illumination which guides the light emitted from the light source incorporated in the light source device to which the endoscope is connected to the illumination window provided in the insertion portion is arranged in a plane together with the optical fiber for signal. You may attach to a flexible optical wiring board.

  Further, it is desirable from the viewpoint of reducing the diameter of the insertion portion that the flexible optical wiring board is spirally wound in the insertion portion. Furthermore, it may be arranged around a single content or a plurality of contents arranged in the insertion portion in a spiral manner. The contents include a fiber bundle or light guide for illumination, a forceps tube or a flexible tube or a hard tube connected thereto, a jet injection tube, and a plurality of contents such as an air / water supply tube. Any of these may be used.

  According to the endoscope of the present invention, since a signal having a high frequency among signals transmitted inside a long insertion portion is transmitted through an optical fiber, unnecessary radiation can be suppressed, and noise is generated in other signals. Can be prevented. In addition, since a signal that is an analog current having a very weak current is transmitted through an optical fiber, noise of the signal itself can be suppressed.

  As shown in FIG. 1, the electronic endoscope 10 having an imaging element at the tip has an elongated shape including an insertion portion 11, a hand operation portion 12, a universal connector 13, and the like. The insertion portion 11 is formed in a tubular shape, and includes a distal end portion 14, a bending portion 15, and a flexible tube portion 16 in order from the distal end. The universal connector 13 is provided at the tip of a cord 18 extending from the hand operation unit 12, and is connected to the processor device 19 and the light source device 17. The processor device 19 includes a driver and a power supply circuit for driving an image sensor (sensor element) built in the distal end portion 14, and an image for encoding an image signal obtained from the image sensor into a composite signal or an RGB component signal. A processing circuit or the like is provided.

  The tip portion 14 is formed of a hard metal material or the like. In addition, the flexible tube portion 16 is a portion that connects the hand operating portion 12 and the bending portion 15 with a small diameter and a long shape, and has flexibility. The bending portion 15 bends up, down, left and right as the angle wire inserted in the insertion portion 11 is pulled in conjunction with the operation of the bending operation portion 12 a provided in the hand operation portion 12. Thereby, the distal end portion 14 is directed in a desired direction in the body cavity, and the observation site imaged by the imaging device is displayed on the monitor 20 via the image processing circuit. Reference numeral 21 denotes a forceps port through which the treatment tool is inserted, and the forceps port 21 is connected to a forceps tube 22 disposed in the insertion portion 11 as indicated by a dotted line.

  As shown in FIG. 2, an observation window 23, illumination windows 24 and 25, a jet injection outlet 26, a forceps outlet 27, an air / water supply nozzle 28 and the like are exposed on the distal end surface 14 a of the distal end portion 14. It has been. The observation window 23 is provided with a part of an objective optical system for taking in image light of the site to be observed in the body cavity, and an imaging element is built in the eyelid of the objective lens system. The illumination windows 24 and 25 incorporate a part of an illumination lens, and guide the illumination light emitted from the light source device with a fiber bundle to irradiate the site to be observed in the body cavity. The forceps outlet 27 communicates with a forceps port 21 provided in the hand operation unit 12 via the forceps tube 22. The air / water supply nozzle 28 injects cleaning water or air for removing dirt from the observation window 23 by operating an air / water supply button provided in the hand operation unit 12. The jet injection outlet 26 injects a fluid supplied from an air supply device, such as air or carbon dioxide gas, toward the site to be observed.

  As shown in FIG. 3, the flexible tube portion 16 includes fiber bundles 30 and 31 for guiding illumination light to the illumination lens, forceps tube 22, air / water supply tube 32, multi-core cable 33, and The contents having a circular cross section such as the jet injection tube 34 are loosely inserted. The fiber bundles 30 and 31 are obtained by bundling a plurality of optical fibers and covering them with an insulating protective cover. The multi-core cable 33 has a cross-sectional shape in which a plurality of signal lines are bundled and covered with an insulating protective coating. Mainly, the power supply system such as the power supply voltage VDD and the ground voltage GND, Is a cable for sending signals of vertical drive pulses ΦV1 to ΦV4 to the image sensor. The signal line is an insulated wire covered with an insulator around the conductor. Reference numeral 35 denotes an angle wire for bending the bending portion 15, and is inserted into the close contact coil pipe 36.

  The flexible tube portion 16 is called a screw tube 37 called a flex that protects the inside while maintaining flexibility in order from the inside, and a blade that covers the screw tube 37 and prevents the screw tube 37 from extending. It is composed of three layers: a net 38 and an outer layer 39 having a resin deposited on the net 38. A flexible optical wiring board 40, which will be described in detail later, is spirally arranged inside the screw tube 37 so as to be inscribed in the screw tube 37. The flexible optical wiring board 40 sends a signal of horizontal drive pulses ΦH1 and ΦH2 of the signal system to the image sensor by optical transmission, and also transmits a long image of the imaging signal Vout from the image sensor by optical transmission. It is a cable.

  As shown in FIG. 4, a part of the objective optical system 41 is exposed in the observation window 23. The illumination light emitted from the illumination windows 24 and 25 is reflected from the site to be observed and enters the observation window 23. Subject light incident from the observation window 23 enters the prism 42 through the objective optical system 41 and is bent inside the prism 42 to form an image on the imaging surface of the image sensor 43. The image sensor 43 is in the form of a bare chip that is not packaged, and the electrodes on the chip are connected to the terminals of the printed circuit board 44 by methods such as wire bonding, TAB (tape automated bonding), and flip chip. For example, a CCD or a CMOS.

  On the printed circuit board 44, an optical converter 45, a multi-core optical terminal portion 46, and a multi-core electric wire terminal portion (not shown) are mounted. Of the terminals of the printed circuit board 44, the terminals for horizontal drive pulses (ΦH1, ΦH2) and the terminal for the imaging signal Vout are connected to the optical converter 45. The optical converter 45 includes an electrical-optical (E / O) converter and an optical-electrical converter, converts the signal of the horizontal driving pulse (ΦH1, ΦH2) from an optical signal to an electrical signal, and performs imaging. The signal Vout is converted from an electric signal to an optical signal. One end of the optical converter 45 is connected to the multi-core optical terminal section 46, and the other multi-core optical connector 47 provided at one end of the flexible optical wiring board 40 is detachably connected.

  Of the terminals of the printed circuit board 44, the terminals for the vertical drive pulses (ΦV1 to ΦV42) and the terminals for the power supply voltage (VDD) and the ground voltage (VSS) are connected to the connection portion for the multicore wire. Yes. The multi-core electric wire connection portion is arranged next to the multi-core optical terminal portion 46. The multicore electric wire connector provided at one end of the multicore electric wire cable 33 is connected to the multicore electric wire connecting portion.

  Without using a multi-core cable connector, a plurality of signal lines are exposed from the multi-core cable, and the insulator of each signal line is peeled off to directly connect the internal conductors to the terminals of the printed circuit board 44. May be. Further, a flexible tube 50 made of synthetic resin is disposed inside the bending portion 15. A forceps tube 22 is connected to one end of the flexible tube 50, and a hard tube 51 disposed inside the distal end portion 14 is connected to the other end. The rigid tube 51 is fixed inside the distal end portion 14, and the distal end is connected to the forceps outlet 27.

  As shown in FIG. 5, a plurality of node rings 53 formed in a short tubular shape are connected to the bending portion 15 inside the screw tube 37. Each node ring 53 is connected to each other by a connecting pin so as to bend vertically and horizontally. On the inner surface of each node ring 53, a wire guide 49 that passes through each close-contact coil pipe 36 is provided. The wire guide 49 acts to cause the angle wire 35 to run along the inner surface of each node ring 53. Each angle wire 35 has a distal end locked to the distal end portion 14 and a proximal end side connected to a bending operation drive mechanism (not shown) of the proximal operation portion 12. The angle wire 35 is exposed from the close contact coil pipe 36 inside the distal end portion 14 and the hand operation portion 12, and the bending operation drive mechanism is vertically and horizontally interlocked with the rotation operation of the bending operation portion 12a. The bending portion 15 is bent by pulling the paired angle wires 35. A screw tube 37, which is an elastic band plate, is spirally wound around the outer periphery of the row of node rings 53, and a net 38 and an outer layer 39 are elastically covered on the outer side.

  A flexible optical wiring board 40 is spirally wound inside the node ring 53 so as to be inside the contact coil pipe 36. In the spiral formed by the flexible optical wiring board 40, there are a plurality of contents such as fiber bundles 30, 31, forceps tube 22, air / water supply tube 32, multi-core cable 33, and jet injection tube 34. An object is loosely inserted in a substantially straight line. In FIG. 5, the description of the contents other than the multicore cable 33 is omitted in order to prevent the drawing from becoming complicated. Moreover, since the bending part 15 curves, there exists a possibility that the node ring 53 or the content may slide with respect to the flexible optical wiring board 40, and the flexible optical wiring board 40 may be damaged. Therefore, a tube made of a flexible material is provided between the node ring 53 including the close contact coil pipe 36 or the content portion, and the flexible optical wiring board 40 is spirally wound around the outer periphery or the inner periphery of the tube. May be. Further, the flexible optical wiring board 40 may be spirally wound between the node ring 53 and the close contact coil pipe 36. In this case, since there is no wire guide 49 between the adjacent wire guides 49 for each of the contact coil pipes 36, a gap is formed between the contact coil pipe 36 and the node ring 53. Therefore, it may be spirally wound during this time.

  On the other hand, inside the flexible tube portion 16, as shown in FIG. 6, the flexible optical wiring board 40 is arranged on the outer periphery of the contact coil pipe 36 and inside the screw tube 37. The proximal end side of the flexible tube portion 16 enters and is fixed inside the housing 52 of the hand operation portion 12. An optical conversion substrate 54 is provided inside the housing 52. A multi-core optical connection portion 55, an optical converter 56, and a multi-core electric wire connection portion 57 are mounted on the light conversion substrate 54. A multi-core optical connector 58 provided at the other end of the flexible optical wiring board 40 is connected to the multi-core optical connection portion 55. The optical converter 56 includes an electrical-optical (E / O) converter and an optical-electrical (O / E) converter, and transmits a horizontal drive pulse (ΦH1, The signal of ΦH2) is converted from an electric signal to an optical signal and sent to the multi-core optical connecting portion 55. Further, the imaging signal Vout transmitted through the multi-core optical connection unit 55 is converted from an optical signal to an electrical signal and sent to the multi-core electric wire connection unit 57. A multi-core electric wire connector 60 provided at one end of the multi-core electric wire cable 59 is connected to the multi-core electric wire connection portion 57. The horizontal drive pulse (ΦH1, ΦH2) signal and the imaging signal Vout are optically transmitted only from the distal end portion 14 to the hand operation unit 12, and between the hand operation unit 12 and the processor device 19, the universal connector 13 is transmitted. It is transmitted by the electric wire through.

  The light conversion substrate 54 is provided with a multi-core electric wire connection portion (not shown) next to the multi-core optical connection portion 55. A multi-core wire connector (not shown) provided at the other end of the multi-core wire cable 33 inside the insertion portion 11 is connected to the multi-core wire connection portion. An electric wire for transmitting signals of vertical drive pulses (ΦV1 to ΦV42), a power supply voltage (VDD), and a ground voltage (VSS) is arranged on the multicore electric wire cable 59 inside the housing 52. The vertical drive pulses (ΦV1 to ΦV42), the power supply voltage (VDD), and the ground voltage (VSS) pass through the multicore wire connector 60 and the multicore wire connection portion 57 for the multicore wire inside the insertion portion 11. It is transmitted to the cable 33. As a result, between the hand operating unit 12 and the processor device 19, the horizontal drive pulses (ΦH1, ΦH2), the imaging signals (Vout), the vertical drive pulses (ΦV1 to ΦV42), the power supply voltage (VDD), and the ground voltage (VSS). ) Is transmitted by the multi-core cable 59. Note that the flexible optical wiring board 40 may be arranged inside the close-contact coil pipe 36.

  The flexible optical wiring board 40 has a configuration in which a plurality of optical fibers 61 are juxtaposed in a long strip-like flexible substrate 62 and multi-core optical connectors 47 and 58 are attached to both ends in the longitudinal direction. As shown in FIG. 7, the flexible substrate 62 has a plurality of optical fibers 61 arranged in a plane on a base film 64 with an adhesive 63, and a cover film 65 placed on the base film 64 so as to be in close contact with the base film 64. The structure is fixed flexibly. The cover film 65 and the base film 64 are made of an insulating material.

  As the optical fiber 61, for example, if the outer diameter is 250 μm, the loss is small, and a quartz fiber generally used in the communication field and various commercially available connectors can be used. . When a single mode optical fiber is used, it is preferable that the core diameter is 10 μm and the refractive index distribution is a step index. When a multimode optical fiber is used, it is preferable that the core diameter is 50 μm or 62.5 μm and the refractive index distribution is a graded index. As the protective film constituting the base film 64 and the cover film 65, polyimide is desirable in consideration of flame retardancy, and polyester (PET) can also be applied. When the protective film is made of polyimide, it is preferable to use a film having a thickness of 25 μm, 50 μm, or 75 μm. When a protective film is made of polyester, it is preferable to use a film having a thickness of 50 μm or 75 μm. The thickness of the adhesive 63 is preferably about 250 μm. The pitch of the optical fiber 61 is preferably matched to the wiring pitch of the multi-core optical connectors 47 and 58. For example, when the diameter of the flexible optical wiring board 40 spirally wound is less than 10 mm, it is preferable to use the multimode optical fiber 61 because transmission loss is small. The flexible optical wiring board 40 may have a structure in which optical fibers 61 are provided in a plane on a base film without an adhesive and coated with silicone rubber from the optical fibers 61.

  As shown in FIG. 8, the processor unit 19 includes a CPU 70, a power supply circuit 71, a timing generator (TG) 72, a CCD driver 73, a correlated double sampling (CDS) circuit 74, and an analog / digital (A / D) converter 75. And an image processing circuit 76. The processor device 19 is electrically connected to the image sensor 43 in the electronic endoscope 10 via the cables 59 and 33 for multicore electric wires and the cable of the flexible optical wiring board 40. Here, the image sensor 43 is described as a CCD.

  The CPU 70 controls each part in the processor device 19 and also comprehensively controls the electronic endoscope 10, the light source device 17, and the like. The power supply circuit 71 generates the power supply voltage VDD and the ground voltage VSS, and supplies the generated power supply voltage VDD and ground voltage VSS to the CCD 43 via the multicore cable 59 and 33. The power supply circuit 71 also generates power to be supplied to each unit in the processor device 19.

  The TG 72 generates a clock signal and supplies it to a CCD driver (drive circuit) 73. Further, the TG 72 generates a clamp pulse and a sample hold pulse for correlated double sampling and supplies them to the CDS circuit 74, and also generates a clock signal for A / D conversion and supplies it to the A / D converter 75. .

  Based on the clock signal input from the TG 72, the CCD driver 73 generates drive signals such as the vertical drive pulses φV1 to φV4, the horizontal drive pulses φH1 and φH2, and the reset pulse φRS described above. The vertical drive pulses φV <b> 1 to φV <b> 4 are transmitted to the CCD 43 through the multicore cable 33 in the insertion portion 11. On the other hand, the horizontal drive pulses φH 1 and φH 2 and the reset pulse φRS are transmitted to the CCD 43 through the flexible optical wiring board 40 in the insertion portion 11. The CCD 43 performs an imaging operation according to the input drive signal.

  The imaging signal Vout output from the CCD 43 is transmitted through the flexible optical wiring board 40 in the insertion unit 11 and transmitted to the CDS circuit 74 provided inside the processor device 19. The CDS circuit 74 is a noise removal circuit, clamps the voltage of the field-through portion of the imaging signal Vout based on the clamp pulse supplied from the TG 72, and determines the imaging signal Vout based on the sample hold pulse supplied from the TG 72. The voltage of the pixel signal portion is sampled and held, and a difference value (voltage difference) between the field through portion and the pixel signal portion is output as a signal.

  The A / D converter 75 quantizes the signal output from the CDS circuit 74 based on the A / D conversion clock signal supplied from the TG 72, for example, into a digital signal of 8 bits (256 gradations). The converted digital signal is input to the image processing circuit 76.

  The image processing circuit 76 performs image processing such as white balance adjustment, gain correction, color interpolation, edge enhancement, gamma correction, and color matrix calculation on the input digital signal to generate image data. The image processing circuit 76 converts the image data into a signal format for display on the monitor 20 and displays the image on the monitor 20.

  The light source device 17 includes a white light source 78 such as a xenon lamp or a halogen lamp, a light source driver 79 for driving the light source 78, and a condensing lens 80 for condensing the light emitted from the light source 78. . The light emitted from the light source 78 is collected by the condenser lens 80, led to the incident ends of the fiber bundles 30 and 31, and led into the insertion portion 11 via the repeater 90 provided in the universal connector 13, Irradiation from the illumination windows 24 and 25 into the body cavity. Reference numeral 85 denotes a multi-core electric wire connecting portion provided on the printed circuit board 44, reference numeral 81 denotes a multi-core electric wire connector 81 detachably connected to the multi-core electric wire connecting portion 85, and reference numeral 82 denotes a hand. Reference numeral 83 denotes a multi-core electric wire connector provided on the light conversion substrate 54 provided in the housing of the operation unit 12, and the multi-core electric wire connection portion 82 is detachably connected thereto.

  When observing the inside of a body cavity using the electronic endoscope 10 configured as described above, the universal connector 13 is connected to the processor device 19 and the light source device 17. The processor device, the light source device, and the monitor 20 are turned on, the insertion portion 11 of the electronic endoscope 10 is inserted into the body cavity, and the inside of the body cavity is illuminated with the illumination light from the light source device 17 and imaged by the CCD 43. The image inside the body cavity is observed on the monitor 20.

  When the power is turned on, the power supply voltage VDD and the ground voltage VSS are sent from the power supply circuit 71 of the processor device 19 to the hand operation unit 12 of the electronic endoscope 10. The power supply voltage VDD and the ground voltage VSS are supplied from the hand operating unit 12 to the CCD 43 incorporated in the distal end portion 14 via the multicore electric wire cable 33 incorporated in the insertion unit 11. Further, the vertical drive pulses ΦV1 to ΦV4 output from the CCD driver 73 are also supplied to the CCD 43 via the multicore electric wire cable 33 built in the insertion portion 11.

  On the other hand, the horizontal drive pulses ΦH1 and ΦH2 and the reset pulse ΦRS output from the CCD driver 73 are supplied to the CCD 43 via the optical fiber 61 of the flexible optical wiring board 40 that is spirally wound inside the insertion portion 11 and incorporated therein. The The imaging signal Vout output from the CCD 43 is also sent to the hand operating unit 12 via the optical fiber 61 of the flexible optical wiring board 40. All signals are transmitted between the hand operating unit 12 and the processor device 19 by electric wires.

  The image pickup signal Vout input to the processor device 19 is denoised by the CDS circuit 74 and converted into a digital signal by the A / D converter 75. The digital signal converted by the A / D converter 75 is converted into image data by the image processing circuit 76 and an image is displayed on the monitor 20.

  As described above, since the horizontal drive pulses φH1 and φH2 and the reset pulse φRS through which a high-frequency signal flows inside the long insertion portion 11 are transmitted by the optical fiber 61, unnecessary radiation can be suppressed. Noise, for example, signals such as vertical drive pulses ΦV1 to ΦV4, power supply voltage VDD, and ground voltage VSS can be prevented. The imaging signal Vout is an analog current having a very weak current. Since the imaging signal Vout is transmitted through the optical fiber 61, noise such as “signal current noise”, “reset noise”, and “dark current noise” can be suppressed, and an image with less noise can be obtained.

  In the above-described embodiment, both the horizontal drive pulses φH1 and φH2 and the reset pulse φRS that easily add noise to other signals and the imaging signal Vout that easily causes noise are optically transmitted inside the insertion unit 11. However, the present invention is not limited to this, and only one of them may be optically transmitted.

  In each of the above embodiments, the CCD 43 is used as the image sensor, but a CMOS may be used instead. Even in the case of using a CMOS, the horizontal drive pulses φH1 and φH2, the reset pulse φRS, and the imaging signal Vout may be transmitted through an optical fiber. Since the CMOS selects and reads a signal by turning on / off a switch by a binary control signal group generated by a logic circuit in the image sensor, a timing for generating a pulse necessary for reading in the image sensor. A logic circuit such as a generator TG or a shift register can be built in to form a single chip. When the CMOS having this configuration is used, the signal output for the read operation from the drive circuit built in the processor device 19 is reduced to three of the sensor clock SCK, the horizontal reference pulse HP, and the vertical reference pulse VP. it can. Therefore, when the CMOS having such a configuration is used, the sensor clock SCK and the horizontal reference pulse HP, which are signals having a high frequency, may be transmitted through an optical fiber. Of course, it is desirable to transmit the imaging signal Vout through an optical fiber.

  In each of the above embodiments, the flexible optical wiring board 40 is spirally wound on the inner side of the node ring 53, but instead of this, for example, the forceps tube 22 or the multicore electric wire cable 33 has a substantially circular cross section. It may be arranged in a spiral around the contents.

  Moreover, in each said embodiment, although the flexible optical wiring board 40 is helically wound and arrange | positioned inside the insertion part 11, you may arrange | position not only spirally but substantially linearly. Moreover, the cable 33 for multi-core electric wires may be omitted, and a known flexible printed board may be used instead. In this case, the flexible printed circuit board may be spirally wound. A flexible printed circuit board has a structure in which an adhesive layer is formed on a film-like insulator (base film), a conductor foil is further formed thereon, and the insulator is covered and protected other than the terminal portion and the soldering portion. It has become. Also, instead of a flexible printed circuit board, thin wires (those in which conductive wires are covered with an insulating film) are placed side by side on an insulating base film and attached with an insulating cover film or silicone rubber. You may make it the structure covered.

  In each of the above embodiments, only the optical fiber is attached to the flexible optical wiring board 40. However, the plurality of electric wires that transmit signals of the power supply voltage VDD, the ground voltage VSS, and the vertical drive pulses ΦV1 to ΦV4 are also optical fibers 61. And may be attached to the flexible optical wiring board 40 by arranging them in the plane direction. In this case, the optical fibers 61 and the electric wires (the conductors are covered with an insulating film) may be alternately arranged on the base film, or the optical fibers 61 and the electric wires may be separately arranged. May be. Also in this case, the flexible optical wiring board 40 may be spirally arranged inside the insertion portion 11.

  Further, as described with reference to FIG. 3, the fiber bundles 30 and 31 are arranged in the insertion portion 11. The fiber bundles 30 and 31 may be omitted, and a new optical fiber for illumination may be attached to the flexible optical wiring board 40 along with the optical fiber 61 for signal transmission in the surface direction. In this way, since the contents inside the insertion portion 11 are reduced, the diameter of the insertion portion 11 can be made compact. Illumination optical fibers are provided so as to protrude from the front and rear ends of the flexible optical wiring board 40, and a plurality of illumination optical fibers protruding from the flexible optical wiring board 40 are integrated into the illumination windows 24 and 25, and the universal connector. 13 may be led to the condensing lens 80 via the repeater 90 provided on the line 13. In this case, since there are two illumination windows 24 and 25, a bundle of illumination optical fibers may be made separately and guided. Also in this case, the flexible optical wiring board 40 may be spirally wound inside the insertion portion 11.

  In the above embodiment, transmission through the optical fiber 61 provided on the flexible optical wiring board 40 is performed from the image sensor 43 to the hand operating unit 12. However, an optical repeater is provided in the universal connector 13 and the optical signal is transmitted to the processor device 19. It may be transmitted.

It is explanatory drawing which shows the use condition of an electronic endoscope. It is explanatory drawing which shows the end surface of a front-end | tip part. It is sectional drawing which shows the inside of a flexible tube part. It is sectional drawing which shows the inside of a front-end | tip part. It is sectional drawing which shows the inside of a bending part. It is sectional drawing which shows the inside of a flexible tube part. It is sectional drawing which shows a flexible optical wiring board. It is explanatory drawing which shows the electrical outline of an electronic endoscope, a processor apparatus, and a light source device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Insertion part 14 Tip part 33 Cable for multi-core electric wires 40 Flexible optical wiring 43 CCD (imaging device)
45, 56 Optical converter 61 Optical fiber

Claims (7)

In an endoscope that transmits an input / output signal that is input to and output from an imaging element provided inside a distal end of an insertion portion that is inserted into the body, through the inside of the insertion portion.
An optical fiber that transmits one or both of a horizontal drive pulse signal and a reset pulse signal input to the image sensor, or an image signal output from the image sensor, of the input / output signals is provided. An endoscope characterized by that.   The endoscope according to claim 1, wherein the optical fibers are attached to a flexible optical wiring board in a plane.   An electric wire for transmitting another signal is provided for the signal transmitted by the optical fiber, and the electric wire is attached to the flexible optical wiring board in a plane along with the optical fiber. Item 2. The endoscope according to Item 2.   An illumination optical fiber for guiding light emitted from a light source built in a light source device connected to the endoscope to an illumination window provided in the insertion portion is provided in the insertion portion, and the illumination optical fiber The endoscope according to claim 2, wherein the endoscope is attached to the flexible optical wiring board along with the optical fiber in a plane.   The endoscope according to any one of claims 2 to 4, wherein the flexible optical wiring board is spirally wound and built in the insertion portion.   The proximal end portion of the insertion portion is connected to a proximal operation portion provided with an operation portion for bending the bending portion provided near the distal end portion of the insertion portion, and the optical fiber is The endoscope according to any one of claims 1 to 5, wherein the endoscope is disposed between an imaging device and the hand operation unit. In an endoscope signal transmission method for transmitting an input / output signal input / output to / from an imaging element provided inside a distal end of an insertion portion to be inserted into a body through the inside of the insertion portion,
Of the input / output signals, either one or both of a horizontal drive pulse signal and a reset pulse signal input to the image sensor, or an image signal output from the image sensor are transmitted through an optical fiber. An endoscope signal transmission method characterized by the above.

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