JP5396448B2 - Endoscope device - Google Patents

Description

  The present invention relates to an endoscope for performing maintenance of pipes in a plant or a building, inspection of an inside of a jet engine, inspection of an interior of a boiler, and the like, and can be used particularly in a place where explosion is highly likely. Related to an endoscope.

  An industrial endoscope apparatus includes a main unit and a scope unit attached to the main unit. The scope unit is provided with an insertion portion made of a flexible insertion tube. A CCD (Charge Coupled Device) image sensor is attached. When monitoring the state of the subject using such an industrial endoscope, the insertion portion is inserted into the subject from the distal end, and the state of the subject is photographed by the CCD image sensor at the distal end of the insertion portion. To do. An image signal from the CCD image pickup device is sent to the main unit, and an imaging screen of the imaged subject is displayed on an LCD (Liquid Crystal Display) monitor for monitoring of the main unit. Such industrial endoscope devices are widely used for various inspections and surveys of plants, pipe maintenance, and the like.

By the way, when such an industrial endoscope apparatus is used in an atmosphere containing a flammable gas or dust, the structure of the apparatus is preferably an explosion-proof structure. As an explosion-proof structure for such an industrial endoscope apparatus, for example, as shown in Patent Document 1, an incombustible gas introduced into a case through an air supply pipe communicating with the case is electrically plugged. In order to prevent explosion, a short arc is generated between the contacts when the electric plug is inserted into the outlet.
JP-A-57-211111

However, in the explosion-proof structure of Patent Document 1, it is necessary to introduce a nonflammable gas into a portion where an arc is generated, and there is a problem that the apparatus becomes large.
By the way, as described in Patent Document 1, the explosion occurs when a short arc generated between the contacts when the electric plug is inserted into the outlet ignites the combustible gas or dust. Therefore, for explosion protection, it is most important to prevent arcing in an environment with flammable gas or dust. In other words, if an arc serving as an ignition source is not generated, there is almost no risk of explosion without using a complicated explosion-proof mechanism such as introducing a nonflammable gas.

  In the case of an optical endoscope as disclosed in Patent Document 1, an arc is generated when a power source for turning on a light source lamp is turned on / off, such as when an electric plug is inserted into an outlet. Therefore, if care is taken not to turn the power on / off, there is almost no risk of explosion even in an environment with flammable gas or dust.

  In contrast, recent industrial endoscopes include a large number of electronic devices such as a circuit for driving a CCD image sensor, a circuit for processing a video signal from the CCD image sensor, and a circuit for processing a video signal. Circuits are in place and the arcing mechanism is becoming more complex. Therefore, even if attention is paid only when the power is turned on / off, it is not possible to prevent an explosion due to the occurrence of an arc.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an endoscope apparatus that can be used sufficiently and reliably even in an environment surrounded by combustible gas or dust.

In order to solve the above-described problems, the present invention is provided in the control unit, which has an imaging element at the tip and has a bending portion, a control unit having a joystick for bending the insertion portion, and the control unit. A display unit for displaying a subject image from the imaging device, the imaging device being provided in the control unit and generating a drive signal for driving the imaging device A drive circuit, a barrier circuit for limiting the energy of the drive signal from the image sensor drive circuit to make the insertion portion side intrinsically safe, and provided in the control unit. An image processing circuit for converting the video signal into an image signal and outputting the image signal to the display unit. It provided in the Control Unit, and limits the energy of the output signal of the imaging element.

Further, the present invention provides an image sensor at the tip, an insertion portion having a bending portion, a control unit having a joystick for bending the insertion portion, and a control unit provided in the control unit. An imaging device including a display unit that displays a specimen image, the imaging device driving circuit that is provided in the control unit and generates a drive signal for driving the imaging device, and the imaging device By limiting the energy of the drive signal from the drive circuit, a barrier circuit is provided in the control unit so that the insertion portion side becomes intrinsically safe, and the video signal from the imaging device is converted into an image signal. An image processing circuit for converting and outputting to the display unit. 11, the barrier circuit for limiting DC energy and AC energy includes at least three Zener diodes, at least one resistor, and at least three coupling capacitors. It is characterized by using a combined circuit .

Further, the present invention provides an image sensor at the tip, an insertion portion having a bending portion, a control unit having a joystick for bending the insertion portion, and a control unit provided in the control unit. An imaging device including a display unit that displays a specimen image, the imaging device driving circuit that is provided in the control unit and generates a drive signal for driving the imaging device, and the imaging device By limiting the energy of the drive signal from the drive circuit, a barrier circuit is provided in the control unit so that the insertion portion side becomes intrinsically safe, and the video signal from the imaging device is converted into an image signal. An image processing circuit for converting and outputting to the display unit. 11, the barrier circuit for limiting DC energy includes a current limiting circuit using at least one resistor or at least two pairs of semiconductors, and at least two Zener diodes. It is used .

Further, the present invention provides an image sensor at the tip, an insertion portion having a bending portion, a control unit having a joystick for bending the insertion portion, and a control unit provided in the control unit. An imaging device including a display unit that displays a specimen image, the imaging device driving circuit that is provided in the control unit and generates a drive signal for driving the imaging device, and the imaging device By limiting the energy of the drive signal from the drive circuit, a barrier circuit is provided in the control unit so that the insertion portion side becomes intrinsically safe, and the video signal from the imaging device is converted into an image signal. An image processing circuit for converting and outputting to the display unit. If correspond to ib apparatus defined in 11, wherein the barrier circuit that limits the AC energy, using at least two coupling capacitors, characterized in that.

Further, the present invention provides an image sensor at the tip, an insertion portion having a bending portion, a control unit having a joystick for bending the insertion portion, and a control unit provided in the control unit. An imaging device including a display unit that displays a specimen image, the imaging device driving circuit that is provided in the control unit and generates a drive signal for driving the imaging device, and the imaging device By limiting the energy of the drive signal from the drive circuit, a barrier circuit is provided in the control unit so that the insertion portion side becomes intrinsically safe, and the video signal from the imaging device is converted into an image signal. An image processing circuit for converting and outputting to the display unit. 11, the barrier circuit for limiting DC energy and AC energy includes a current limiting circuit using at least one resistor or at least two pairs of semiconductors, and at least two Zener diodes. And a circuit in which at least two coupling capacitors are combined .

  According to the first aspect of the present invention, an endoscope apparatus including a scope unit having an insertion portion to be inserted into a subject and a main unit to which the scope unit is connected, the endoscope device being disposed in the scope unit. A barrier circuit that restricts energy for the circuit to be connected, and the part extending beyond the part where the barrier circuit is provided is intrinsically safe, so the inside of the device where flammable gas or dust exists (For example, inside of a gasoline tank, a plant, an engine, etc.) Observation at a place where there is a risk of explosion is possible.

  Here, explosion prevention will be described. Explosion-proof is standardized by IEC, ATEX (Europe), FM (America), CSA (Canada), TIIS (Japan), etc. and certified as an explosion-proof device by a certification body. In the present specification, description will be made based on the IEC standard (IEC 60079). However, it is needless to say that the portions that substantially correspond to the standards of other countries can be applied to the standards of other countries and do not exclude other standards.

  Considering the mechanism of the explosion, the explosion is caused by an increase in temperature by an ignition source in an environment where there is a combustible gas or dust and oxygen. For example, in gasoline tanks, plants, and engines, the fuel is combustible gas or dust, and there is air around it. Under these circumstances, an ignition source can cause an explosion. Conversely, the elements of the explosion are: 1. flammable gas or dust; 2. oxygen; If one of these three elements is missing, no explosion will occur. Therefore, in the present application, the explosion-proof endoscope system is realized by cutting off the energy ignition element by the ignition source.

In IEC 60079, it is defined as Zone 0, Zone 1 and Zone 2 as the use place for the explosion-proof product. Zone 0 has the highest risk, Zone 1 has the next highest risk, and Zone 2 has the next highest risk. The hazardous area is designated as Hazardous Area, and the non-hazardous area is designated as Non-Hazardous Area.
The device structure is defined as ia device, ib device, and Type-n. The ia device is the most reliable against explosion, and the ib device is the next. The ia device can be used in Zone0 and Zone1, and the ib device can be used only in the Zone1 area. Equipment that can be used in the Zone 0 or Zone 1 area is called intrinsically safe. A Type-n device can be used in Zone2.

  According to the invention of claim 2, the barrier circuit uses at least three Zener diodes and at least one resistor for limiting DC energy, and at least for limiting AC energy. Three coupling capacitors are used, and a combination of at least three Zener diodes, at least one resistor, and at least three coupling capacitors is used for limiting DC energy and AC energy. Thus, since the intrinsically safe explosion-proof portion is an ia device based on the explosion-proof regulations, highly reliable explosion-proof is possible.

  According to the invention of claim 3, the barrier circuit has a current limiting circuit using at least one resistor or at least two pairs of semiconductors, and at least two Zener diodes for limiting DC energy, For limiting AC energy, use at least two coupling capacitors; for limiting DC energy and AC energy, limit current using at least one resistor or at least two sets of semiconductors. Since a combination of a circuit, at least two Zener diodes and at least two coupling capacitors is used, and the intrinsic safety explosion-proof part is an ib device based on the explosion-proof regulations, High explosion-proof becomes possible.

  According to the invention of claim 4, a fuse is further inserted to limit the direct current energy. Since the direct current energy flowing into the intrinsically safe explosion-proof part side can be controlled, a Zener diode having a small rated power can be used.

  According to the invention of claim 5, the scope unit includes a scope connector that is detachably attached to the main unit, and the barrier circuit is provided on the scope connector and includes a portion that extends from the scope connector. By using intrinsically safe explosion-proof, the control unit, the insertion part and the optical adapter can be intrinsically safe.

  According to a sixth aspect of the present invention, the scope unit includes a control unit provided at a proximal end portion of the insertion portion, and the barrier circuit is provided at the control unit and extends from the control unit first. By making the part to perform intrinsically safe explosion-proof, the part of the insertion part and the optical adapter can be made intrinsically safe.

  According to a seventh aspect of the present invention, the barrier circuit is provided in the main unit, and a part extending from the main unit is intrinsically safe, so that the scope connector, the insertion part, and the optical adapter part. Can be intrinsically safe.

  According to the eighth aspect of the present invention, signal lines for transmitting / receiving signals to the CCD, LED drive signals, thermistor signals, etc. extending to the tip of the scope unit, and motor drive signals, switch signals, video signals, etc., supplied to the control unit Since the other signal lines are insulated from each other, energy isolation between the scope unit and the control unit signal group can be performed.

  According to the ninth aspect of the present invention, since the coating material is applied to the circuit elements of the barrier circuit, it is possible to reduce the creepage distance required for separating the intrinsically safe explosion-proof side and the other parts. And the area of the barrier circuit can be reduced. Therefore, it is possible to reduce the size of the device.

  According to the tenth aspect of the present invention, the identification means for identifying the intrinsically safe part is provided, so that the user can easily recognize the intrinsically safe part.

  According to the eleventh aspect of the invention, since the color-specific markers are applied as the identification means, the user can recognize the intrinsically safe explosion-proof portion at a glance.

  According to the twelfth aspect of the present invention, the image pickup device is disposed at the distal end of the scope unit, and the energy for driving the image pickup device is limited by the barrier circuit. Therefore, the energy of the image pickup device can be limited.

  According to the invention of claim 13, the barrier circuit for limiting the energy for driving the image sensor limits the energy of the transfer pulse to the image sensor and operates as a differentiating circuit for waveform shaping. Therefore, the energy limiting circuit can also be used as another circuit.

  According to the invention of claim 14, the barrier circuit for limiting the energy of the imaging output from the imaging device is provided in the preceding stage of the preamplifier, and operates as a matching resistor that transmits the scope cable of the CCD VideoOut signal. The energy limiting circuit can be shared with other circuits.

  According to the fifteenth aspect of the present invention, the illumination element is disposed at the distal end of the scope unit, and the energy for driving the illumination element is limited by the barrier circuit, so that the energy flowing into the illumination element is ignited. It can be made smaller than energy.

  According to the invention of claim 16, the barrier circuit for limiting the energy for driving the lighting element includes a current limiting circuit using at least one resistor or at least two sets of semiconductors, a plurality of zener diodes, Thus, the energy limiting barrier circuit is effective even in at least a single failure state.

  According to the seventeenth aspect of the present invention, the LED illumination element is driven by a positive potential with respect to the ground level and a negative potential with respect to the ground level. The driving voltage can be lowered. Thereby, the Vz Zener voltage of the Zener diode required for the barrier circuit can also be set lower than in the case of only the positive power source or only the negative power source.

  According to the eighteenth aspect of the present invention, the temperature sensor for detecting the ambient temperature of the subject is disposed at the tip of the scope unit, and the energy of the detection output of the temperature sensor is limited by the barrier circuit. The energy flowing into the temperature sensor can be made smaller than the ignition energy.

  According to the nineteenth aspect of the present invention, the barrier circuit for limiting the energy of the detection output of the temperature sensor includes a current limiting circuit using resistors or at least two sets of semiconductors, and a plurality of zener diodes. The energy flowing into the temperature sensor can be easily made smaller than the ignition energy.

  According to the invention of claim 20, since the motor for bending the insertion portion of the scope unit is provided and the energy for driving the motor is limited by the barrier circuit, the energy flowing into the motor is reduced. It can be made smaller than the flammable energy.

  According to the invention of claim 21, a barrier circuit for limiting energy for driving a motor includes a current limiting circuit using a resistor or at least two sets of semiconductors for limiting energy of a logic signal to the motor, and a plurality of current limiting circuits. Therefore, the energy flowing into the motor can be made smaller than the ignition energy.

  According to the invention of claim 22, since the operation switch for operating each part is disposed and the energy of the logic signal from the switch is limited by the barrier circuit, the logic level is not destroyed. The energy flowing into the switch can be made smaller than the ignition energy.

  According to the invention of claim 23, the barrier circuit for limiting the energy of the logic signal from the switch is composed of a current limiting circuit using a resistor or at least two sets of semiconductors, and a plurality of zener diodes. Therefore, the energy flowing into the switch can be easily made smaller than the ignition energy without breaking the logic level.

  According to the invention of claim 24, the imaging device is disposed at the distal end of the scope unit, the illumination unit is disposed at the main unit, and the light from the illumination unit is guided by the optical guide from the distal end of the scope unit. Irradiated and the barrier circuit limits the energy for driving the image sensor, so that intrinsically safe explosion-proofing of an endoscope using a lamp can be realized.

  According to the invention of claim 25, the optical image from the distal end of the scope unit is guided to the main unit by the fiber scope or the bore scope, and the illumination element is disposed at the distal end of the scope unit, and the illumination element is driven by the barrier circuit. Since the energy to be used is limited, intrinsically safe explosion-proofing of fiberscope and borescope endoscopes can be realized.

  According to the twenty-sixth aspect of the present invention, since the illumination element is an LED illumination means, the subject can be reliably illuminated while suppressing power consumption.

  According to the invention of claim 27, since the main unit is provided with a power source and the power source uses a secondary battery, not only can the power source be reliably supplied but also the convenience can be improved. it can.

  According to the invention of claim 28, the intrinsically safe explosion-proof portion satisfies the explosion-proof specification of Zone 0 or Zone 1 based on the explosion-proof regulations, so that it can be used reliably even in a combustible gas or dust environment.

  According to the invention of claim 29, the portion provided on the main unit side with respect to the intrinsically safe explosion-proof portion satisfies the Zone 2 explosion-proof specification based on the explosion-proof regulations, so that the configuration is simplified, and the combustible gas or dust environment is simplified. Can be used reliably even under.

  According to the invention of claim 30, comprising a warning means for issuing a warning, and when the temperature detected by the temperature sensor reaches a predetermined threshold value, it is controlled to issue a warning by the warning means, The user can be alerted.

  According to the invention of claim 31, since the display means for displaying the observation image of the subject is provided, and the display means satisfies the explosion-proof specification of Zone 0, Zone 1 or Zone 2 based on the explosion-proof regulations, it is reliable even in a flammable gas or dust environment. Can be used for

It is a perspective view showing appearance composition of an endoscope apparatus of a 1st embodiment of the present invention. It is a perspective view which shows the external appearance structure of the control unit in the endoscope apparatus of the 1st Embodiment of this invention. It is a perspective view for demonstrating the structure of the front-end | tip of the insertion part in the endoscope apparatus of the 1st Embodiment of this invention. It is explanatory drawing at the time of using the endoscope apparatus of the 1st Embodiment of this invention in an explosion danger area | region. It is a block diagram which shows the internal structure of the 1st Embodiment of this invention. It is a block diagram which shows the structure of the CPU video board in the 1st Embodiment of this invention. It is a block diagram which shows the structure of the power board in the 1st Embodiment of this invention. It is a block diagram which shows the structure of the CCD drive board and DSP board in the 1st Embodiment of this invention. It is a block diagram which shows the structure of the LED drive board in the 1st Embodiment of this invention. It is a connection diagram used for description of the circuit structure in the front-end | tip part of the insertion part in the 1st Embodiment of this invention. It is a connection diagram used for description of the barrier circuit in the first embodiment of the present invention. It is a connection diagram used for description of the barrier circuit in the first embodiment of the present invention. It is a connection diagram used for description of an energy limiting circuit. It is a connection diagram used for description of an energy limiting circuit. It is a perspective view used for description of the identification means which shows an intrinsically safe explosion-proof part. It is the top view and sectional drawing used for description of the coating process of a barrier circuit. It is a block diagram which shows the internal structure of the 2nd Embodiment of this invention. It is a block diagram which shows the internal structure of the 3rd Embodiment of this invention. It is a block diagram which shows the internal structure of the 4th Embodiment of this invention. It is a block diagram used for description of the LCD monitor using a cold cathode ray tube. It is a block diagram used for description of the LCD monitor using LCD. It is a block diagram which shows the internal structure of the 5th Embodiment of this invention. It is a block diagram which shows the internal structure of the 6th Embodiment of this invention. It is a block diagram which shows the internal structure of the 7th Embodiment of this invention. It is a block diagram which shows the internal structure of the 8th Embodiment of this invention. It is a block diagram which shows the internal structure of the 9th Embodiment of this invention. It is a block diagram which shows the internal structure of the 10th Embodiment of this invention. It is a block diagram which shows the internal structure of the 11th Embodiment of this invention. It is a block diagram which shows the internal structure of the 12th Embodiment of this invention. It is a block diagram which shows the internal structure of the 13th Embodiment of this invention. It is a block diagram which shows the internal structure of the 14th Embodiment of this invention. It is a block diagram which shows the internal structure of the 15th Embodiment of this invention. It is a schematic diagram which shows collectively the main structural part and specification area of the said 1st to 9th embodiment. It is a schematic diagram which shows collectively the main structural part and specification area of the said 10th to 15th embodiment. It is explanatory drawing which shows the state of the scope environmental temperature detected by the thermistor, and the mode of the warning display by a warning means with a graph.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(1) 1st Embodiment FIG. 1: shows the outline | summary of the endoscope apparatus of the 1st Embodiment of this invention. In FIG. 1, a main unit 1 controls the entire endoscope apparatus. A front panel 11 for performing various settings is provided on the top surface of the main unit 1. An LCD monitor 12 for displaying a monitor image is attached to the side surface of the main unit 1. A belt 13 can be attached to the main unit 1 so that a user can hang from the shoulder and perform a hands-free operation.

  The scope unit 2 includes a control unit 3, an insertion portion 4 attached to the control unit 3, and an optical adapter 8 that can be attached to and detached from the distal end of the insertion portion 4. The control unit 3 is detachably attached to the main unit 1 by a scope connector 5. In the first embodiment of the present invention, as will be described later, a barrier circuit for limiting energy is provided in the scope connector 5. The main unit 1 and the control unit 3 are connected by a universal cable 6.

  A CCD image sensor is attached to the distal end of the insertion portion 4. The insertion unit 4 has flexibility so that various subjects can be imaged.

  A bending portion 9 is provided at the distal end portion of the insertion portion 4. A motor is provided in the control unit 3, and the bending portion 9 can be bent vertically and horizontally by this motor. By bending the bending portion 9, the shooting direction can be freely set.

  An optical adapter 8 is detachably attached to the distal end of the insertion portion 4. Optical adapters 8 having various optical performances are prepared, and by changing the optical adapter 8, different viewing angles, viewing directions, brightness, observation depth, and the like can be changed.

  The control unit 3 is a part that operates the endoscope apparatus based on a user instruction. As shown in FIG. 2, a grip portion 21 is formed in the control unit 3. The user can hold the grip portion 21 and operate the endoscope at hand.

  As shown in FIG. 2A, the control unit 3 is provided with a joystick 22, a zoom lever 23, a brightness adjustment lever 24, and a boost button 25. The joystick 22 is used to operate the direction of the bending portion 9 at the distal end of the insertion portion 4. The boost button 25 is a gain changing button.

  Further, as shown in FIG. 2B, a freeze recording button 26 is disposed on the side surface of the control unit 3. When the freeze recording button 26 is pressed, the still image at that time is captured and recorded.

  FIG. 3 shows the configuration of the distal end of the insertion portion 4 and the optical adapter 8. As shown in FIG. 3A, a CCD image sensor 31, hybrid integrated circuits (hereinafter abbreviated as HIC) 32 and 33, and a thermistor 34 are disposed at the distal end of the insertion portion 4. The HIC 32 is provided with a buffer for the output signal of the CCD image sensor 31. The HIC 33 is equipped with a comparator for shaping the waveform of the horizontal transfer pulse. The thermistor 34 is provided to detect the ambient temperature of the scope tip.

  Wiring for transmitting signals and power to these electronic circuits is housed in the insertion portion 4 and is connected to the main unit 1 via the universal cable 6 and the scope connector 5 as shown in FIG. ing. As will be described later, the scope connector 5 is provided with a barrier circuit, which prevents excessive energy from being transmitted to signals and power supplies to these electronic circuits. As a result, it can be used in an environment where there is a risk of explosion.

  As shown in FIG. 3, the optical adapter 8 is provided with an LED module 36 on which a plurality of LED chips 35, 35,. The subject is irradiated by turning on the LED chips 35, 35,.

  The optical adapter 8 is provided with contacts 37a and 37b. The contacts 37 a and 37 b are connected to the LED module 36. On the other hand, contacts 38 a and 38 b are provided at the distal end of the insertion portion 4. When the optical adapter 8 is attached to the distal end of the insertion portion 4, as shown in FIG. 3B, the contacts 38a and 38b and the contacts 37a and 37b are brought into contact with each other, as shown in FIG. The optical adapter 8 is fixed to the distal end of the insertion portion 4. Thereby, power is supplied to the LED chips 35, 35,... Arranged in the LED module 36.

  FIG. 4 shows an outline of a method of using the endoscope apparatus according to the first embodiment of the present invention in an environment where there is a risk of explosion.

  First, setup is performed as shown in FIG. Specifically, in the setup, the battery 41 and the memory card 42 are attached to the main unit 1, the main unit 1 and the scope unit 2 are connected by the scope connector 5, or the optical adapter 8 is connected to the distal end of the insertion portion 4. It is work to attach. Such a setup operation is always performed in an area where there is no risk of explosion (non-hazardous area).

  As shown in FIG. 4B, when the setup is completed, the endoscope apparatus is moved to the vicinity of an area where there is a risk of explosion. Then, as shown in FIG. 4C, the scope unit 2 is placed in an area where there is a risk of explosion (Zone 0 or Zone 1 area), and the subject is imaged. At this time, as shown in FIG. 4C, the main unit 1 is placed in an area where there is no risk of explosion (Non-hazardous area) or an area where the risk of explosion is small (Zone 2 area).

  In addition, when exchanging equipment such as the battery 41, the memory card 42, the optical adapter 8, or removing the scope unit 2, the endoscope apparatus must be installed as shown in FIG. Move to an area where there is no risk of explosion (Non-hazardous area).

  FIG. 5 is a block diagram showing an internal configuration of the endoscope apparatus according to the first embodiment of the present invention. In FIG. 5, the main unit 1 is provided with a CPU (Central Processing Unit) video board 51 and a power board 52. A battery 41 is attached to the main unit 1.

  The CPU video board 51 controls the entire endoscope apparatus. The CPU video board 51 controls signal processing of captured images and recording / reproduction of image signals. Further, the CPU video board 51 performs processing such as measurement, and performs processing for measuring the environmental temperature measured by the thermistor 34. An LCD monitor 12 is attached to the main unit 1. The LCD monitor 12 displays a captured image.

  The power board 52 supplies power necessary for various boards based on the power from the battery 41.

  The scope connector 5 connects the main unit 1 and the scope unit 2 (the control unit 3, the insertion portion 4, and the optical adapter 8). The scope connector 5 is provided with a CCD drive board 61, a DSP (Digital Signal Processor) board 62, an LED drive board 63, and a barrier circuit 64.

  The CCD drive board 61 forms various signals and power sources necessary for driving the CCD image pickup device 31 such as a horizontal transfer pulse and a vertical transfer pulse. The DSP board 62 performs signal processing of image signals from the CCD image sensor 31. The LED drive board 63 drives the LED module 36. The barrier circuit 64 includes circuits (motor drive board 72, motor 71, CCD image pickup device 31, thermistor 34, HICs 32 and 33) disposed in the scope unit 2 (control unit 3, insertion unit 4, optical adapter 8). It limits the energy for the LED module 36).

  Thus, since the barrier circuit 64 that restricts the energy for each circuit disposed in the scope unit 2 is provided, the portion extending from the position of the barrier circuit 64 to the tip, in this example, the control unit 3 The insertion part 4 and the optical adapter 8 are intrinsically safe.

  The control unit 3 is provided with a motor 71, a motor drive board 72, and a switch 73. The motor 71 is for bending the bending portion 9 at the distal end of the insertion portion 4. For example, a brushless motor is preferably used as the motor 71 so that no spark is generated. However, a brush motor may be used if the motor driving energy is small. The motor drive board 72 drives the motor 71. The switch 73 corresponds to various buttons and switches (joystick 22, zoom lever 23, brightness adjustment lever 24, boost button 25, freeze recording button 26, etc.) set by the user.

  The insertion unit 4 is provided with a CCD image pickup device 31, HICs 32 and 33, and a thermistor 34 at the tip thereof. The CCD image sensor 31 photoelectrically converts an optical image of a subject into an electrical signal. The HIC 32 is a buffer for the imaging output from the CCD imaging device 31. The HIC 33 shapes the horizontal transfer pulse for the CCD image sensor 31. The thermistor 34 measures the ambient temperature.

  The optical adapter 8 is provided with an LED module 36 and a lens 40. The LED module 36 irradiates the vicinity of the subject.

  FIG. 6 shows the configuration of the CPU video board 51. As shown in FIG. 6, the CPU video board 51 is provided with a CPU 101. A memory 103, an OSD (On Screen Display) circuit 104, an A / D converter 111, and an encoder 106 are connected to the bus 102 of the CPU 101. The OSD circuit 104 superimposes various display signals on the screen. The decoder 105 decodes the YCrCb image data into RGB image data. The encoder 106 encodes image data such as RGB into image data of a standard system (NTSC or the like).

  Further, a ROM (Read Only Memory) 107, a memory card 42, and a serial interface 109 are connected to the CPU 101. The memory card 42 is used for storing captured images. The serial interface 109 is for connecting to an external device such as a personal computer. The CPU 101 is supplied with a clock from an RTC (Real Time Clock) circuit 110. The RTC circuit 101 performs time management.

  Further, the detection output of the thermistor 34 is supplied to the CPU 101 via the A / D converter 113. A motor control signal is output from the CPU 101, and this motor control signal is output toward the motor drive board 72 via the buffer 114. The CPU video board 51 is provided with a DC / DC converter 115.

  FIG. 7 shows the configuration of the power board 52. As shown in FIG. 7, the power board 52 is provided with a DC / DC converter 121 for forming a power source of each part from the battery 41. A fuse 122 is provided in the power line from the battery 41.

  FIG. 8 shows the configuration of the CCD drive board 61 and the DSP board 62. As shown in FIG. 8, the CCD drive board 61 is provided with a clock oscillator 131 and a timing signal generation circuit 132. Various signals (vertical pulses V1 to V4, horizontal transfer pulse HPLS, reset pulse RST, sub pulse Sub) for driving the CCD image sensor are formed by the timing signal generation circuit 132. There is a CCD power supply (Vcc, Vdd and SHD) 134 for driving the CCD image pickup device 31. There is an SHD (threshold hold voltage) that is a reference voltage of a comparator that shapes a horizontal pulse. These power supplies and signals are output toward the CCD image pickup device 31 via the buffers 133a to 133g.

  As shown in FIG. 8, the DSP board 62 includes a preamplifier 141, an A / D converter 142, a video signal processing circuit 143, and a D / A converter 144. A clock is supplied from the CCD drive board 61 to the DSP board 62. An imaging signal from the CCD imaging device 31 is amplified by a preamplifier 141 and converted into digital data by an A / D converter 142. Then, the video signal processing circuit 143 performs processing such as defect correction and white balance correction. Further, the video signal processing circuit 143 converts the image pickup signal into YCrCb image data. This image data is converted into an analog signal by the D / A converter 144 and output.

  FIG. 9 shows the configuration of the LED drive board 63. The LED drive board 63 is provided with a DC / DC converter 151, constant current circuits 152 and 153, and buffers 154 and 155. The DC / DC converter 151 forms a positive drive voltage of the LED and a negative drive voltage of the LED. The constant current circuit 152 sets the drive current on the positive side of the LED, and the constant current circuit 153 sets the drive current on the negative side of the LED.

  The reason why the LED drive current is set to the positive side and the negative side with respect to the ground level is to prevent explosion. That is, normally, if the LED drive voltage is Vf, the LED is given a voltage of Vf with respect to the ground level. On the other hand, in this embodiment, + Vf / 2 and -Vf / 2 are given to the LED. In this way, even if the voltage applied to the LED is the same as Vf, the voltage from the ground level becomes 1/2, which is advantageous for explosion prevention. For example, in the intrinsic safety explosion-proof standard of IEC 60079-11, if it exceeds + 30V, the limit on the creepage distance of the barrier circuit becomes severe. For example, ± 20V or less is desirable, and it is advantageous in terms of explosion protection because it is handled at ± 15V. Become.

  FIG. 10 shows the configuration of the distal end of the insertion portion 4. In FIG. 10, the HIC 33 is provided with an SHD power supply input terminal, a horizontal transfer pulse HPLS input terminal, a Vdd power supply input terminal, a ground terminal, and a horizontal transfer pulse output terminal. The HIC 33 shapes the waveform of the horizontal transfer pulse input by the comparator and outputs it. This horizontal transfer pulse is supplied to the CCD image pickup device 31 to the horizontal transfer pulse input terminal.

  The CCD image pickup device 31 is directly supplied from the CCD drive board 61 with a Vcc power supply, four vertical transfer pulses V1 to V4, a reset pulse RST, and a sub pulse Sub.

  The HIC 32 is provided with an input terminal for a Vcc power supply, an input terminal for a CCDOut signal, a ground terminal, and an output terminal for a CCD video signal. An output signal from the CCD image sensor 31 is input to the HIC 32. Then, the data is output via a buffer constituting the HIC 32 and sent to the DSP board 62.

  The operation of the endoscope apparatus according to the first embodiment of the present invention shown in FIG. 5 will be described.

  In FIG. 5, the image light of the subject taken in through the lens of the optical adapter 8 is imaged on the light receiving surface of the CCD image sensor 31 at the tip of the insertion portion 4. The CCD image pickup device 31 is driven by vertical transfer pulses V1 to V4 from the CCD drive board 61 and horizontal transfer pulses HPLS sent from the CCD drive board 61 via the HIC 33. An imaging signal is output from the CCD imaging device 31. This imaging signal is sent to the DSP board 62 via the HIC 32.

  As shown in FIG. 8, the image pickup signal from the CCD image pickup device 31 is amplified by the preamplifier 141 by the DSP board 62 and converted into digital data by the A / D converter 142. Then, the video signal processing circuit 143 performs processing such as defect correction and white balance correction. Further, the video signal processing circuit 143 converts the image pickup signal into YCrCb image data. This image data is converted into an analog signal by the D / A converter 144 and output.

  In FIG. 5, the output signal of the DSP board 62 is supplied to the CPU video board 51. As shown in FIG. 6, the image signal from the DSP board 62 is sent to the decoder 105 and converted into an image signal such as RGB by the decoder 105. This image signal is digitized by the A / D converter 111, sent to the bus 102, and temporarily stored in the memory 103.

  Various signal processes are performed on the image data stored in the memory 103. This image data is sent to the encoder 106 via the bus 102. The encoder 106 converts the RGB image data into standard image data. This image data is converted into an analog signal by the D / A converter 112 and outputted, and sent to the LCD monitor 12.

  When capturing an image, the image data stored in the memory 103 is read out, sent to the memory card 42, and this image data is recorded in the memory card 42.

  Next, the barrier circuit 64 in the first embodiment of the present invention will be described in detail. As described above, the barrier circuit 64 is provided in the scope connector 5 and prevents excess energy from being transmitted to the electronic circuit disposed in the scope unit 2. The barrier circuit 64 secures a circuit-like creeping distance so as to be separated from the intrinsically safe side on the substrate.

  FIGS. 11 and 12 show an example of the barrier circuit 64. First, as shown in FIG. 11A, the barrier circuit 64 inserts a high resistance 201 into the line to the thermistor 34 (line L3 in FIG. 5) to limit energy. The thermistor 34 measures the temperature by detecting a change in resistance value due to temperature. For this reason, an energy limiting circuit that can detect a change in potential is used. The resistance of the thermistor energy limiting circuit at this time is preferably selected in accordance with the change resistance value of the thermistor. For example, 1 kΩ to 10 kΩ is appropriate. Also, three Zener diodes 240a, 240b, 240c and a resistor 201-2 for limiting the rated power of the resistor 201 are connected to limit the voltage.

  As shown in FIG. 11B, a fuse 202, three Zener diodes 203a, 203b, 203c, and a resistor 204 are inserted in the barrier circuit 64 in the line for the Vcc power supply (line L10 in FIG. 5). Restrict DC energy.

Here, how to select the fuse 202, the three Zener diodes 206a, 206b, 206c and the resistor 204 will be described. The Zener voltage Vz of the three Zener diodes 206a, 206b, and 206c is selected so that Vcc + 15V is output to L7 in a normal circuit operation state without reaching the breakdown voltage from Vcc + 15V. For example, in the example of FIG. 11A, a Zener with Vz = 18V may be selected.
The value of the fuse 202 does not blow the fuse in normal circuit operation. When an abnormal voltage is applied to the Vcc + 15V terminal, the fuse 202 works and functions to keep it within the rating of the Zener voltage Vz of the Zener diodes 206a, 206b, 206c. For example, when the normal operating current is about 10 mA, a fuse rating of about 50 mA may be selected.

The resistor 204 limits the Zener voltage generated by the Zener diodes 206a, 206b, and 206c by the resistor when an abnormal voltage is applied to the Vcc + 15V terminal. The current can be limited as the resistance value increases, but if the resistance value is increased, a potential drop due to the resistor 204 during normal operation becomes a problem. Therefore, it is necessary to reduce the potential drop during the normal operation while limiting the energy at the time of abnormality. For example, by using a value of about 100Ω for the resistor 204, the energy limit at the time of abnormality and the potential drop at normal time may be set to appropriate values.
In the above example, the energy applied from the Vcc + 15V line is exemplified. Fuse 202 = 50 mA
3 Zener diodes 206a, 206b, 206c = 18V rating (maximum 18.9V),
If the resistance 204 = 82Ω,
18.9V / 82Ω = 230 mA is the maximum current value that flows on the explosion-proof regulations (it is not limited by 50 mA of the fuse 202 in the explosion-proof regulations calculation).
18.9V × 230 mA = 4347 mW, and about 4 W of energy is designed to flow into the Vcc + 15V line.

As shown in FIG. 11C, a fuse 205, three zener diodes 206a, 206b, 206c, and a resistor 207 are inserted in the barrier circuit 64 in the line for the Vdd power supply (line L7 in FIG. 5). Restrict DC energy.
Based on the same idea as described above for Vcc + 15V, a fuse, a Zener diode, and a resistance value are selected for Vdd + 6V. However, since Vdd has a voltage of 6V, it is appropriate to use a Zener voltage with a rating of about 7.2V. Further, the energy applied from this line can be calculated based on the same idea as described above for Vcc + 15V.

  As shown in FIG. 11D, a fuse 208, three Zener diodes 209a, 209b, 209c, and a resistor 210 are inserted in the barrier circuit 64 in the line for the SHD power supply (line L9 in FIG. 5). Restrict DC energy. Hereinafter, the method of selecting a fuse, a Zener diode, and a resistance value, and the calculation of energy applied from this line are the same as those described above.

  In the line (line L8) of the horizontal transfer pulse HPLS, in the barrier circuit 64, as shown in FIG. 11E, a differentiation circuit including capacitors 211a to 211c, capacitors 212a to 212c, and a resistor 213 is used as an energy limiting circuit. Use. At this time, the capacitors 211a to 211c and the capacitors 212a to 212c are circuits that limit AC energy. The DC energy is limited by the configuration of the fuse 241, the three Zener diodes 242 a, 242 b, 242 c, and the resistor 213. Thus, the AC energy is limited by three series capacitors, and the DC energy is limited by a fuse, a Zener diode, and a resistor of the types shown in (B) to (D) above.

  As shown in FIG. 11 (F), the reset pulse RST line (line L4 in FIG. 5) and the vertical transfer pulses V1 to V4 lines (line L6 in FIG. 5) include a fuse 215, a zener as shown in FIG. The diodes 216a, 216b, 216c and the resistor 217 are inserted to limit the DC energy of the DC bias, and the energy of the AC component is limited by the three coupling capacitors 218a, 218b, 218c.

  As shown in FIG. 11G, the fuse 221, the Zener diodes 222 a, 222 b, 222 c, and the resistor 223 are inserted into the sub-pulse Sub line (line L 5 in FIG. 5) in the barrier circuit 64. The DC energy is restricted and the energy of the AC component is restricted by the three coupling capacitors 225a, 225b, and 225c.

  As shown in FIG. 12A, the output signal line of the CCD image pickup device 31 (line L11 in FIG. 5) includes a fuse 226, three Zener diodes 227a in front of the preamplifier 229, as shown in FIG. 227b, 227c and resistor 228 are inserted to limit the DC energy. The resistor 228 also functions as an impedance matching resistor for matching the input side to the scope connector 5 side and the output side of the signal transmission path from the CCD image pickup device 31 side.

  On the positive LED illumination line (line L12 in FIG. 5), in the barrier circuit 64, as shown in FIG. 12B, a fuse 230, three zener diodes 231a, 231b, 231c, and a resistor 232 are provided. Insert and limit DC energy.

  In the negative LED illumination line (line L13 in FIG. 5), the barrier circuit 64 includes a fuse 233, three zener diodes 234a, 234b, 234c, and a resistor 235 as shown in FIG. Insert and limit DC energy. Since the voltage is negative, the Zener diode is connected in the opposite direction to other barrier circuits.

  As shown in FIG. 12D, a fuse 236, three zener diodes 237a, 237b, 237c, and a resistor 238 are connected to a line (line L1 in FIG. 5) for supplying power to the motor drive board 72 in the control unit 3. To limit the DC energy.

  As shown in FIG. 12 (E), a high resistance 239 is inserted into the ON / OFF state of the motor in the control unit 3 and signal lines (line L2 in FIG. 5) of various switches, and three Zener diodes are provided. 243a, 243b, and 243c are inserted, a resistor 239-2 for limiting power is included in the rating of the high resistance 239, and direct current energy is limited.

  In the barrier circuit 64, the fuse used as the energy limiting circuit is a barrier network fuse with guaranteed fusing performance. For example, it is preferable to use one that conforms to the Barrier Network Standards EN50020 standard.

As described above, in the first embodiment of the present invention, as shown in FIG. 5, the scope connector 5 is provided with the barrier circuit 64 that restricts the energy of the signal and the power supply for each circuit, and is intrinsically safe. I try to satisfy the explosion-proof. That is, in the first embodiment of the present invention, the barrier circuit 64 limits the signal and power supply energy to each circuit so that no spark is generated even if a short circuit occurs. Yes. In this way, intrinsically safe explosion-proofing is realized by eliminating the ignition source, which is one of the factors that cause explosions.
In the first embodiment of the present invention, the scope unit 2 satisfies the ia equipment standard and realizes intrinsic safety explosion-proof.

  In the first embodiment of the present invention, as shown in FIG. 5, the scope connector 5 is provided with a barrier circuit 64 for restricting the energy of signals and power to each circuit, thereby satisfying intrinsic safety explosion-proof. I am doing so. As shown in FIG. 11 and FIG. 12, the barrier circuit 64 is provided with three Zener diodes and one resistor for limiting the direct current energy to limit the alternating current energy. Is provided with three coupling capacitors. This is because even if two of the three Zener diodes and coupling capacitors are damaged, the energy is limited by the remaining one. Thereby, the standard of ia apparatus can be satisfied. If the ib device standard is satisfied, two of these are sufficient.

  The energy limiting circuit constituting the barrier circuit 64 is basically a combination of the configurations shown in FIGS. 13 and 14, and the current limiting circuit in the barrier circuit 64 shown in FIGS. Based on this.

  FIG. 13 shows an example of an energy limiting circuit that satisfies the standard of ia equipment. FIG. 13A shows an energy limiting circuit for direct current. As shown in FIG. 13A, in the energy limiting circuit for direct current, a fuse F1 and a resistor R1 are provided in a line L101. Further, three Zener diodes D1a, D1b, and D1c are provided between the line L101 and the ground. Thus, by providing the three Zener diodes D1a, D1b, and D1c, the voltage of the line L101 is prevented from increasing. The three zener diodes D1a, D1b, and D1c are provided so that reliability can be maintained even if two of the zener diodes D1a, D1b, and D1c are damaged, and the ia device is used as an explosion-proof device. This is to satisfy the standards.

  FIG. 13B illustrates an energy limiting circuit for alternating current. As shown in FIG. 13B, in the energy limiting circuit for alternating current, three coupling capacitors C1a, C1b, and C1c are provided in the line L102. Thus, by providing the coupling capacitors C1a, C1b, and C1c, the circuit is cut off in a direct current manner to limit energy. The three coupling capacitors C1a, C1b, and C1c are provided so that reliability can be maintained even if two of the capacitors C1a, C1b, and C1c are damaged, and the ia device is used as an explosion-proof device. This is to satisfy the standards. As the values of the capacitors C1a, C1b, and C1c, capacitors that are AC-coupled and do not distort the waveform are selected. A high withstand voltage ceramic capacitor having a withstand voltage of 500 V or more is used as the AC coupling capacitor.

  FIG. 13C shows an energy limiting circuit in the case where an AC component is on the DC bias. As shown in FIG. 13C, in this case, the resistor R2 and the three coupling capacitors C2a, C2b, and C2c are connected in parallel and inserted into the line L103. In this case, the DC component is energy limited by the fuse 244, the three Zener diodes 245a, 245b, 245c and the resistor R2. For the AC component, energy is limited by the coupling capacitors C1a, C1b, and C1c.

  FIG. 13D shows an energy limiting circuit for logic signals (signals indicated by H level and L level). As shown in FIG. 13D, the resistor R3 is inserted in the line L104 to limit energy. In addition, three Zener diodes 246a, 246b, and 246c are inserted, and a resistor R3-2 that limits the current is included in the rated power of the resistor R3. For example, if the signal is a normal logic voltage of about + 5V to + 3V, the resistance value of the resistor R3 may be selected from about 1 kΩ to about 10 kΩ.

  FIG. 14 shows an example of an energy limiting circuit that satisfies the definition of the ib equipment of the explosion-proof standard. FIG. 14A shows an energy limiting circuit for direct current. As shown in FIG. 14A, in the energy limiting circuit for direct current, a fuse F2 and current limiting circuits T1a and T1b including two transistors Q1 and Q2 are provided in a line L105. Further, two Zener diodes D2a and D2b are provided between the line L105 and the ground. Note that the two sets of current limiting circuits T1a and T1b are provided so that reliability can be maintained even if one of the current limiting circuits T1a and T1b is damaged, and the ib equipment standard is satisfied. It is for doing so. The two zener diodes D2a and D2b are provided so that reliability can be maintained even if two of the zener diodes D2a and D2b are damaged, and the provision of the ib device is satisfied as an explosion-proof device. This is to make it happen.

  Thus, by providing the two Zener diodes D2a and D2b, the voltage of the line L105 is prevented from rising.

  Also, with this configuration, when the current becomes excessive, the current is interrupted by the current limiting circuits T1a and T1b. That is, in the current limiting circuits T1a and T1b, when the current flowing through the line L105 increases, the voltage across the resistor Rs increases, and the transistor Q2 is turned on when it exceeds the VBE of the transistor Q2. As a result, the transistor Q1 is turned off. Thereby, the current flowing through the line L105 is interrupted. The fuse F2 is set so as not to exceed the rated capacity of the two Zener diodes and the two sets of transistors. Note that although a transistor is used in FIG. 14A, an FET that performs the same function may be used as long as it is a semiconductor.

  FIG. 14B illustrates an energy limiting circuit for alternating current. As shown in FIG. 14B, in the energy limiting circuit for alternating current, two coupling capacitors C3a and C3b are provided in the line L106. Thus, by providing the coupling capacitors C3a and C3b, the circuit is cut off in a direct current manner to limit energy. The two coupling capacitors C3a and C3b are provided so that the reliability can be maintained even if one of the capacitors C3a and C3b is broken so that the standard of the ib device is satisfied. It is to do.

  FIG. 14C shows an energy limiting circuit in the case where an AC component is on the DC bias. As shown in FIG. 14C, in this case, the resistor R4 and the two coupling capacitors C4a and C4bc are connected in parallel and inserted into the line L107. In this case, the DC component is energy limited by the fuse 247, the two Zener diodes 248a and 248b, and the resistor R4. For the AC component, energy is limited by the coupling capacitors C4a and C4b.

  FIG. 14D illustrates an energy limiting circuit for a logic signal (a signal indicated by an H level and an L level). As shown in FIG. 14D, a resistor R5 is inserted in the line L108, two zener diodes 249a and 249b are inserted, and a resistor R5-2 that limits the current is included in the rated power of the resistor R5. Note that the component parts (resistor R4 and resistor R5) for limiting the DC energy shown in FIG. 14 can be replaced with limiting elements by two sets of transistors as shown in the current limiting circuits T1a and T1b. In this case, by using two sets of transistors, the number of components increases and the mounting area increases, but the potential drop due to the resistors R4 and R5 during normal operation, which has occurred in the resistors R4 and R5, is reduced. Therefore, there is an advantage that the drive voltage of the circuit that drives the intrinsically safe explosion-proof part can be lowered.

  As described above, in the first embodiment of the present invention, the barrier circuit 64 is provided in the scope connector 5. Therefore, the portion extending from the position of the barrier circuit 64 to the tip, in this example, the control unit 3, the insertion portion 4, and the optical adapter 8 is intrinsically safe and can be used in a portion where there is a risk of explosion. As a result, it is possible to safely and reliably perform internal inspections of jet engines, plants, gasoline tanks, and the like.

  In the first embodiment of the present invention, since the barrier circuit 64 is provided in the scope connector 5, the intrinsic safety explosion-proof is the portion extending from the position of the barrier circuit 64 to the tip. Yes, that is, the control unit 3, the insertion portion 4, and the optical adapter 8 are intrinsically safe. On the user side, it is necessary to recognize which part is intrinsically safe in each unit constituting the endoscope apparatus.

  In addition, if the user can easily know that there are few intrinsically safe explosion-proof parts when viewed from the dangerous area during use, it is possible to prevent the parts that are not intrinsically safe from being accidentally pulled into the dangerous area. Therefore, in the first embodiment of the present invention, color markings are attached as identification means so that the intrinsically safe explosion-proof portion and the non-explosive portion can be seen at a glance. Furthermore, the fact that there are only a few remaining intrinsically safe parts is indicated by marking.

  That is, in the case of the first embodiment of the present invention, the barrier circuit 64 is provided in the scope connector 5, and the control unit 3, the insertion portion 4, and the optical adapter 8 are intrinsically safe. In this case, as shown in FIG. 15, the universal cable 6 connecting the scope connector 5 and the control unit 3 is colored as a marking indicating that it is not an intrinsically safe explosion-proof portion from here to the main unit 1 side. A portion 15 is provided. Thereby, from the coloring part 15 to the main unit 1, it can be alerted to a user that it remove | deviates from the part of intrinsically safe explosion-proof. In this example, the colored portion 15 is provided in the universal cable 6 at a predetermined distance from the scope connector 5 in order to inform that the intrinsically safe explosion-proof portion is small by coloring. It is also possible to color-code the parts that are not so. Moreover, if the coloring part 15 is made into fluorescent color or bright blue, it will be easy to be recognized by a user.

  In the first embodiment of the present invention, the coating material is applied to the chip component of the circuit arranged in the barrier circuit 64. That is, as shown in FIG. 16, the chip component 17 is performed on the pattern 20 on the substrate 16 by soldering. A coating material 18 is applied on the circuit board. As the coating material 18, a silicon coating material is used. By applying such a coating material, it is possible to secure a necessary insulation distance defined in IEC 60079-11. That is, the clearance distance La between patterns in FIG. 16 is 2.0 mm when the withstand voltage is 30 V and no coating material is applied. On the other hand, when the coating material 18 is applied, 0.7 mm is sufficient. If the creepage distance is 0.7 mm, a small chip component such as a chip component of 3216 size, for example, can be adopted as the resistor, the AC coupling capacitor, and the semiconductor constituting the energy limiting circuit.

In the first embodiment of the present invention, the thermistor 34 is provided at the distal end of the insertion portion 4. The temperature detection output of the thermistor 34 may be used to warn of the danger of explosion when the ambient temperature reaches a predetermined value or more. When assuming the failure mode, the intrinsically safe explosion-proof part must have the temperature value of the intrinsically safe explosion-proof part within the upper limit temperature value of the target gas or dust. Therefore,
It is necessary to satisfy the relationship of (environmental temperature) + (temperature rise at failure) <ignition temperature value. For example, when the environment gas used is 100 degrees Celsius and the target gas that determines the ignition degree of the ignition temperature is n-hexane used for jet engine fuel, etc., the ignition temperature of n-hexane is about 220 degrees Therefore, the temperature rise value at the time of failure must be suppressed to about 100 degrees. That means
It is necessary to satisfy the relationship of (environmental temperature +100 degrees) + (temperature rise value at the time of failure 100 degrees) <ignition temperature value 220 degrees

  Based on the provisions of IEC 60079, the rank of application is determined by the temperature of the ignition level of the gas targeted for the intrinsically safe explosion-proof device. A gas with an ignition level of 200 degrees or less is called T3 in the rank. In FIG. 35, it is necessary to suppress the environmental temperature and the temperature rise value below the T3 limit value of 200 degrees. In order to realize an explosion-proof device targeted at the T3 ignition degree, when the temperature rise value caused by the energy limited by the barrier circuit at the time of failure is 100 degrees, the environmental temperature satisfying the explosion-proof specification should be 100 degrees or less. There is a need. In FIG. 35, when the environmental temperature is 100 degrees or less, it can be used as an explosion-proof specification, but when it is 100 degrees or more, it is non-explosion-proof.

  As shown in FIG. 35, when the temperature detected by the thermistor 34 exceeds, for example, 100 ° C. (threshold), a warning is displayed on the LCD monitor 12 or a warning sound is emitted by the warning means. As a result, the user can be informed that the periphery of the distal end of the insertion portion 4 has exceeded a predetermined temperature, and can be alerted. The warning means is not limited to display and warning sound, and may be, for example, vibration, lighting of a lamp, or blinking. Moreover, although the threshold value is set to 100 ° C., the temperature is not limited to this, and the temperature can be changed as appropriate.

(2) Second Embodiment Next, a second embodiment of the present invention will be described. FIG. 17 shows a second embodiment of the present invention. In this embodiment, as in the first embodiment, the scope connector 5 is provided with a barrier circuit 64, and a portion extending from the barrier circuit 64 first, that is, the control unit 3, the insertion portion 4, and the optical device. The adapter 8 is intrinsically safe. In the second embodiment, in the configuration of the first embodiment, the signal line extending to the distal end of the scope unit 2 and the other signal lines are insulated and separated by the insulating member 19 to achieve energy separation. I have to. About this insulating material, when a cable having a thickness of 0.5 mm or more is adopted, energy can be reliably separated. Needless to say, the same effect can be obtained by applying an insulating material to the signal extending to the tip of the scope unit 2. The other parts are the same as those in the first embodiment, and the corresponding parts are denoted by the same reference numerals, and the description thereof is omitted.

(3) Third Embodiment FIG. 18 shows a third embodiment of the present invention. In this embodiment, similarly to the first embodiment, the scope connector 5 is provided with a barrier circuit 64, and a portion extending from the barrier circuit 64 first, that is, the control unit 3, the insertion portion 4, and the optical circuit. The adapter 8 is intrinsically safe. In the third embodiment, buffers 39 a to 39 k are inserted into the path of the insertion unit 4. In this embodiment, as in the first embodiment, the control unit 3, the insertion portion 4, and the optical adapter 8 are intrinsically safe. In this embodiment, since the buffers 39a to 39k are inserted in the path of the insertion unit 4, even when the insertion unit 4 is long, a necessary signal level can be secured and the S / N ratio can be improved.
(4) Fourth Embodiment FIG. 19 shows a fourth embodiment of the present invention. In this embodiment, similarly to the first embodiment, the scope connector 5 is provided with a barrier circuit 64, and a portion extending from the barrier circuit 64 first, that is, the control unit 3, the insertion portion 4, and the optical circuit. The adapter 8 is intrinsically safe. In the fourth embodiment, the control unit 3 is also provided with an LCD monitor 74. Thereby, the user can perform the monitoring work while looking at the LCD monitor 74 of the control unit 3.

  In this example, since the control unit 3 is intrinsically safe, it is necessary to use an intrinsically safe LCD monitor 74 as well.

  That is, some LCD monitors use a cold cathode tube as a backlight and others use an LCD as a backlight.

  FIG. 20 is an example of an LCD monitor using LEDs as a backlight. In FIG. 20, the power applied to the power supply terminal 251 is converted into high voltage by the inverter 252 and supplied to the cold cathode ray tube 253 of the backlight. Thereby, the cold cathode ray tube 253 is controlled to be turned on. The impeller 252 generates a high voltage of about 2 kV when it is lit, and normally about 600 V. Further, power from the power supply terminal 251 is supplied to the LCD power supply circuit 254, and the LCD power supply circuit 254 forms a power supply for panel driving. A video signal from the input terminal 255 is supplied to the panel drive circuit 256, and the LCD panel 257 is driven by the panel drive circuit 256. As a result, an image is displayed on the LCD panel 257.

  FIG. 21 is an example of an LCD monitor using LEDs as a backlight. In FIG. 21, the power applied to the power supply terminal 261 is supplied to the LCD drive circuit 262 and also to the LCD power supply circuit 264. The LCD drive circuit 262 drives the LED backlight 263 with a low voltage of 20V or less. The LED backlight 263 is driven by the LCD drive circuit 262. The LCD power supply circuit 264 forms a power source for panel drive. A video signal from the input terminal 265 is supplied to the panel drive circuit 266, and the LCD panel 267 is driven by the panel drive circuit 266. As a result, an image is displayed on the LCD panel 267.

  As for the LCD monitor 12 provided on the main unit 1 side, since the main unit 1 is not intrinsically safe, the LCD shown in FIG. 21 is used as the backlight even if a cold cathode tube is used as the backlight shown in FIG. Whatever you use can be used in the same way.

  However, the LCD monitor 74 provided on the control unit 3 side is required to be intrinsically safe since the control unit 3 is intrinsically safe. A backlight using a cold cathode tube as the backlight shown in FIG. 20 is not suitable for intrinsically safe explosion protection because a high voltage is applied to the cold cathode ray tube 253. As the LCD monitor 74 provided on the control unit 3 side, it is necessary to use a backlight using LEDs as the backlight shown in FIG. In particular, if the main unit 1 side is a Type-n device used in Zone 2, the LCD monitor is a Type-n LCD monitor corresponding to Zone 2 and not an intrinsically safe device corresponding to ia device or ib device. Also good.

(5) Fifth Embodiment FIG. 22 shows a fifth embodiment of the present invention. This embodiment is an example applied to the scope unit 2 without a control unit. That is, in the embodiment described above, the scope unit 2 includes the control unit 3, the insertion portion 4, and the optical adapter 8, and various operations can be performed by the control unit 3.

  On the other hand, in this example, the insertion portion 4 is extended from the main unit 1 via the scope connector 5, and all operations are performed on the main unit 1 side. In addition, a switch 53 for performing various operations is provided in the main unit 1. A motor 71 for moving the bending portion 9 at the distal end of the insertion portion 4 and a motor drive board 72 are provided on the scope connector 5.

  In this embodiment, as in the first embodiment, the scope connector 5 is provided with the barrier circuit 64. Accordingly, the portion extending from the barrier circuit 64 first, that is, the insertion portion 4 and the optical adapter 8 are intrinsically safe.

(6) Sixth Embodiment FIG. 23 shows a sixth embodiment of the present invention. In the first to fifth embodiments described above, the barrier circuit 64 is provided in the scope connector 5, whereas in this embodiment, the barrier circuit 64 is provided in the control unit 3.

  In the first embodiment, the scope connector 5 is provided with a CCD drive board 61, a DSP board 62, and an LED drive board 63. On the other hand, in the sixth embodiment, a CCD drive board 61, a DSP board 62, and an LED drive board 63 are provided in the control unit 3. A barrier circuit 64 is disposed at the subsequent stage.

  Since the portion extending from the barrier circuit 64 first becomes intrinsically safe explosion-proof, in the sixth embodiment, the insertion portion 4 and the optical adapter 8 become intrinsically safe explosion-proof. In the first embodiment, the control unit 3, the insertion section 4, and the optical adapter 8 are intrinsically safe, whereas in this embodiment, the control unit 3 is not intrinsically safe. However, in this embodiment, the scope connector 5 only needs to be a connector that couples the main unit 1 and the scope unit 2, and the configuration can be simplified. An LCD can also be attached to the control unit.

(7) Seventh Embodiment FIG. 24 shows a seventh embodiment of the present invention. In the first to fifth embodiments described above, the barrier circuit 64 is provided in the scope connector 5, and in the sixth embodiment, the barrier circuit 64 is provided in the control unit 3. In this embodiment, the barrier circuit 64 is provided in the main unit 1.

  In the first embodiment, the scope connector 5 is provided with a CCD drive board 61, a DSP board 62, and an LED drive board 63. On the other hand, in the seventh embodiment, a CCD drive board 61, a DSP board 62, and an LED drive board 63 are arranged in the main unit 1. A barrier circuit 64 is disposed at the subsequent stage.

  Since the portion extending from the barrier circuit 64 first is intrinsically safe explosion-proof, in the seventh embodiment, the scope connector 5, the control unit 3, the insertion portion 4, and the optical adapter 8 are intrinsically safe explosion-proof. The motor may be disposed in the scope connector, and an Ex-LCD (explosion-proof LCD) may be attached to the control unit.

(8) Eighth Embodiment FIG. 25 shows an eighth embodiment of the present invention. In this embodiment, as in the seventh embodiment, the main unit 1 is provided with the barrier circuit 64, and the portion extending from the barrier circuit 64 first, that is, the scope connector 5, the control unit 3, and the insertion The part 4 and the optical adapter 8 are intrinsically safe. In the eighth embodiment, buffers 39 a to 39 k are inserted into the path of the insertion unit 4. In this embodiment, since the buffers 39a to 39k are inserted in the path of the insertion unit 4, even when the insertion unit 4 is long, a necessary signal level can be secured and the S / N ratio can be improved.

(9) Ninth Embodiment FIG. 26 shows an eighth embodiment of the present invention. This embodiment is an example applied to a scope unit 2 that does not have a control unit. In this example, the insertion portion 4 is extended from the main unit 1 via the scope connector 5, and all operations are performed on the main unit 1 side. In addition, a switch 53 for performing various operations is provided in the main unit 1. A motor 71 and a motor drive board 72 for moving the bending portion 9 at the distal end of the insertion portion 4 are provided in the main unit 1.

  In this embodiment, a barrier circuit 64 is provided in the main unit 1 as in the seventh embodiment. Accordingly, the portion extending from the barrier circuit 64 first, that is, the scope connector 5, the insertion portion 4, and the optical adapter 8 are intrinsically safe explosion-proof.

(10) Tenth Embodiment FIG. 27 shows a tenth embodiment of the present invention. In the embodiments described above, the LED module 36 is used as a light source for irradiating the subject. In this embodiment, a lamp light source is used as the illumination unit to irradiate the subject. Yes.

  That is, in FIG. 27, the main unit 1 is provided with a lamp 56 and a lamp driving board 55 for driving the lamp 56. The lamp drive board 55 is supplied with power from the power board 52. Light from the lamp 56 is guided to the optical adapter 8 through the light guide 57.

  In the tenth embodiment, the scope connector 5 is provided with a barrier circuit 64, and the portions extending from the barrier circuit 64, that is, the control unit 3, the insertion portion 4, and the optical adapter 8 are intrinsically safe. It becomes. Further, the Ex-LCD may be attached to the control unit.

(11) Eleventh Embodiment FIG. 28 shows an eleventh embodiment of the present invention. In this embodiment, a lamp 56 and a lamp driving board 55 are provided in the main unit 1 so as to irradiate a subject using a lamp light source, as in the tenth embodiment.

  In the tenth embodiment, the scope connector 5 is provided with a barrier circuit 64. In contrast, in the eleventh embodiment, a CCD drive board 61, a DSP board 62, and a barrier circuit 64 are provided in the control unit 3. Since the portion extending from the barrier circuit 64 first is intrinsically safe, the insertion portion 4 and the optical adapter 8 are intrinsically safe in this eleventh embodiment.

(12) Twelfth Embodiment FIG. 29 shows a twelfth embodiment of the present invention. In this embodiment, a lamp 56 and a lamp driving board 55 are provided in the main unit 1 so as to irradiate a subject using a lamp light source, as in the tenth embodiment.

  This embodiment is an example applied to the scope unit 2 without a control unit. In this example, the insertion portion 4 is extended from the main unit 1 via the scope connector 5, and all operations are performed on the main unit 1 side.

  In the twelfth embodiment, a switch 53 for performing various operations is provided in the main unit 1. A motor 71 and a motor drive board 72 for moving the bending portion 9 at the distal end of the insertion portion 4 are provided in the main unit 1.

  In the twelfth embodiment, a CCD drive board 61 and a DSP board 62 are provided in the main unit 1. A barrier circuit 64 is disposed at the subsequent stage. Since the portion extending first from the barrier circuit 64 is intrinsically safe, the insertion portion 4 and the optical adapter 8 are intrinsically safe in this twelfth embodiment.

(13) Thirteenth Embodiment FIG. 30 shows a thirteenth embodiment of the present invention. In the embodiments described above, the CCD image pickup device 31 is attached to the tip of the insertion portion 4 and the image of the CCD image pickup device 31 is monitored. On the other hand, in the thirteenth embodiment, the observation image is guided to the main unit by the fiber scope or the bore scope by the image guide.

  That is, in FIG. 30, the video camera 58 is placed on the main unit 1. The video camera 58 is supplied with power from the power board 52. The control unit 3 is provided with an LED drive board 63 and a barrier circuit 64.

  An image guide 81 is provided at the distal end of the insertion portion 4, and an image from the image guide 81 is guided to the scope connector 5 via the fiber scope 82 or the borescope. This image is taken by the video camera 58 and displayed on the LCD monitor 12.

  In the thirteenth embodiment, an LED drive board 63 is disposed in the control unit 3, and a barrier circuit 64 is disposed in the subsequent stage. Since the portion extending first from the barrier circuit 64 is intrinsically safe, the insertion portion 4 and the optical adapter 8 are intrinsically safe in this thirteenth embodiment.

(14) Fourteenth Embodiment FIG. 31 shows a thirteenth embodiment of the present invention. In this embodiment, similarly to the above-described thirteenth embodiment, the observation image is guided to the main unit by the fiber scope or the bore scope by the image guide.

  In the thirteenth embodiment described above, the LED drive board 63 and the barrier circuit 64 are disposed in the control unit 3, whereas in this embodiment, the LED drive board 63 and the barrier circuit are connected to the scope connector 5. 64 is provided and the control unit 3 is not provided. Since the portion extending from the barrier circuit 64 first becomes intrinsically safe explosion-proof, in the fourteenth embodiment, the insertion portion 4 and the optical adapter 8 become intrinsically safe explosion-proof.

(15) Fifteenth Embodiment FIG. 32 shows a thirteenth embodiment of the present invention. In this embodiment, similarly to the above-described thirteenth embodiment, the observation image is guided to the main unit by the fiber scope or the bore scope by the image guide.

  In the above-described thirteenth embodiment, the LED drive board 63 and the barrier circuit 64 are disposed in the control unit 3, whereas in this embodiment, the LED drive board 63 and the barrier circuit are provided in the main unit 1. The circuit 64 is provided, and the control unit 3 is not provided. Since the portion extending from the barrier circuit 64 first is intrinsically safe explosion-proof, in the thirteenth embodiment, the scope connector 5, the insertion portion 4, and the optical adapter 8 are intrinsically safe explosion-proof.

  Note that FIGS. 33A to 33E and FIGS. 34F to 34K are schematic diagrams collectively showing main components and specification areas of the above embodiment. 33A shows the outline of the first to fourth embodiments, FIG. 33B shows the fifth embodiment, FIG. 33C shows the sixth embodiment, and FIG. ) Shows the outline of the seventh and eighth embodiments, and (E) shows the outline of the ninth embodiment. FIG. 34 (F) shows the tenth embodiment, (G) the eleventh embodiment, (H) the twelfth embodiment, (I) the thirteenth embodiment, (J ) Shows the outline of the fourteenth embodiment, and (K) shows the outline of the fifteenth embodiment.

The present invention is not limited to the above-described embodiments, and various modifications and applications can be made without departing from the gist of the present invention.
In the embodiments of the present application, the CCD drive signal and signal reception have been described in detail as an example of the image sensor, but a barrier circuit that limits energy in the same way is also provided in driving another sensor such as a CMOS image sensor. Can realize intrinsically safe explosion-proof.
Further, in the tenth to twelfth embodiments, the configuration example in which the lamp light source is provided on the main unit side is shown, but the illumination means is realized by using LED light source means or laser illumination means instead of the lamp light source unit May be.

Furthermore, in the embodiment of the present application, the battery may be any secondary battery means such as a lithium ion battery, a lead battery, a nickel metal hydride battery, or a fuel cell.
The endoscope system shown in the present application employs a battery as a power source, thereby increasing the mobility of the device and taking the total amount of energy that can be supplied from only the energy from the battery.
Therefore, there is no energy supply from an AC power source from an AC adapter or the like, and the endoscope system does not need to be grounded. Therefore, the energy that can be supplied at the time of abnormality is considered only in terms of the battery energy total according to the regulations based on IEC 60079. Well, the configuration of the energy limiting circuit is small, light and easy to implement.

Further, in the present application, the optical adapter is configured to be detachably attached to the distal end of the scope unit. However, the optical adapter may not be attached or detached and may be integrated with the insertion unit of the scope unit. In such a case, there is an advantage that the length of the hard part of the scope tip is shortened.
Further, in the present application, the display means is an LCD unit using an LCD panel, but the display unit is not limited to this, and an organic EL panel, an LED panel, or the like may be used. When these display means are explosion-proof compatible, they can be used as explosion-proof compatible LCDs in the danger areas of Zone 0, 1, and 2. In particular, assuming use in the Zone 2 area, the LCD unit may have a Type-n device structure, and is simpler, smaller, lighter, and lower than the structures of Zone 0 and Zone 1 intrinsically safe ia devices and ib devices. Convenient because it can be realized at low cost.

1: Main board 2: Scope unit 3: Control unit 4: Insertion unit 5: Scope connector 6: Universal cable 8: Optical adapter 9: Bending unit 12: LCD monitor 15: Coloring unit 17: Chip component 18: Cord material 31: CCD image sensor 32: HIC
33: HIC
34: Thermistor 35: LED chip 36: LED module 41: Battery 42: Memory card 51: Video board 52: Power board 61: CCD drive board 62: DSP board 63: LED drive board 64: Barrier circuit 71: Motor 72: Motor Drive board

Claims (12)

An insertion portion having an imaging element at the tip and having a curved portion;
A control unit having a joystick for bending the insertion portion;
A display unit provided in the control unit and displaying a subject image from the imaging device;
An endoscopic device comprising:
An image sensor driving circuit that is provided in the control unit and generates a drive signal for driving the image sensor;
A barrier circuit for limiting the energy of the drive signal from the image sensor drive circuit so that the insertion side becomes intrinsically safe, and
An image processing circuit provided in the control unit for converting a video signal from the image sensor into an image signal and outputting the image signal to the display unit;
I have a,
The endoscope apparatus according to claim 1, wherein the barrier circuit is provided in the control unit and limits energy of an output signal of the imaging device. In the case where the intrinsic safety explosion-proof part is made to correspond to the ia device defined in IEC 60079-11,
The endoscope apparatus according to claim 1, wherein the barrier circuit that limits direct current energy uses at least three Zener diodes and at least one resistor. In the case where the intrinsic safety explosion-proof part is made to correspond to the ia device defined in IEC 60079-11,
The endoscope apparatus according to claim 1, wherein the barrier circuit that limits AC energy uses at least three coupling capacitors. In the case where the intrinsic safety explosion-proof part is made to correspond to the ia device defined in IEC 60079-11,
The barrier circuit for limiting DC energy and AC energy uses a circuit in which at least three Zener diodes, at least one resistor, and at least three coupling capacitors are combined. The endoscope apparatus according to any one of claims 1 to 3. When making the intrinsic safety explosion-proof part correspond to an ib device defined in IEC 60079-11,
2. The barrier circuit for limiting DC energy uses a current limiting circuit using at least one resistor or at least two pairs of semiconductors, and at least two Zener diodes. Endoscope device. When making the intrinsic safety explosion-proof part correspond to an ib device defined in IEC 60079-11,
The endoscope apparatus according to claim 1, wherein the barrier circuit that limits AC energy uses at least two coupling capacitors. When making the intrinsic safety explosion-proof part correspond to an ib device defined in IEC 60079-11,
The barrier circuit for limiting DC energy and AC energy includes: a current limiting circuit using at least one resistor or at least two pairs of semiconductors; at least two Zener diodes; and at least two coupling capacitors. The endoscope apparatus according to claim 1, wherein a combined circuit is used.   The endoscope apparatus according to any one of claims 2 to 7, wherein a fuse is further inserted into the barrier circuit that limits direct current energy. An insertion portion having an imaging element at the tip and having a curved portion;
A control unit having a joystick for bending the insertion portion;
A display unit provided in the control unit and displaying a subject image from the imaging device;
An endoscopic device comprising:
An image sensor driving circuit that is provided in the control unit and generates a drive signal for driving the image sensor;
A barrier circuit for limiting the energy of the drive signal from the image sensor drive circuit so that the insertion side becomes intrinsically safe, and
An image processing circuit provided in the control unit for converting a video signal from the image sensor into an image signal and outputting the image signal to the display unit;
Have
In the case where the intrinsic safety explosion-proof part is made to correspond to the ia device defined in IEC 60079-11,
The barrier circuit for limiting DC energy and AC energy uses a circuit in which at least three Zener diodes, at least one resistor, and at least three coupling capacitors are combined. Endoscopic device. An insertion portion having an imaging element at the tip and having a curved portion;
A control unit having a joystick for bending the insertion portion;
A display unit provided in the control unit and displaying a subject image from the imaging device;
An endoscopic device comprising:
An image sensor driving circuit that is provided in the control unit and generates a drive signal for driving the image sensor;
A barrier circuit for limiting the energy of the drive signal from the image sensor drive circuit so that the insertion side becomes intrinsically safe, and
An image processing circuit provided in the control unit for converting a video signal from the image sensor into an image signal and outputting the image signal to the display unit;
Have
When making the intrinsic safety explosion-proof part correspond to an ib device defined in IEC 60079-11,
The endoscope apparatus characterized in that the barrier circuit for limiting DC energy uses a current limiting circuit using at least one resistor or at least two pairs of semiconductors and at least two Zener diodes. An insertion portion having an imaging element at the tip and having a curved portion;
A control unit having a joystick for bending the insertion portion;
A display unit provided in the control unit and displaying a subject image from the imaging device;
An endoscopic device comprising:
An image sensor driving circuit that is provided in the control unit and generates a drive signal for driving the image sensor;
A barrier circuit for limiting the energy of the drive signal from the image sensor drive circuit so that the insertion side becomes intrinsically safe, and
An image processing circuit provided in the control unit for converting a video signal from the image sensor into an image signal and outputting the image signal to the display unit;
Have
When making the intrinsic safety explosion-proof part correspond to an ib device defined in IEC 60079-11,
An endoscope apparatus characterized in that the barrier circuit for limiting AC energy uses at least two coupling capacitors. An insertion portion having an imaging element at the tip and having a curved portion;
A control unit having a joystick for bending the insertion portion;
A display unit provided in the control unit and displaying a subject image from the imaging device;
An endoscopic device comprising:
An image sensor driving circuit that is provided in the control unit and generates a drive signal for driving the image sensor;
A barrier circuit for limiting the energy of the drive signal from the image sensor drive circuit so that the insertion side becomes intrinsically safe, and
An image processing circuit provided in the control unit for converting a video signal from the image sensor into an image signal and outputting the image signal to the display unit;
Have
When making the intrinsic safety explosion-proof part correspond to an ib device defined in IEC 60079-11,
The barrier circuit for limiting DC energy and AC energy includes: a current limiting circuit using at least one resistor or at least two pairs of semiconductors; at least two Zener diodes; and at least two coupling capacitors. An endoscope apparatus using a combined circuit.

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