JP6257391B2 - Endoscope system - Google Patents

Description

  The present invention relates to a communication system, a transmission device, and a reception device that transmit a plurality of signals.

  Conventionally, in the medical field, an endoscope system (imaging system) is used when observing an organ of a subject such as a patient. An endoscope system includes, for example, an endoscope that has an elongated shape having flexibility, and an insertion portion provided with an image pickup element that captures an in-vivo image at the tip is inserted into a body cavity of a subject. On the other hand, a processing device (processor unit) that is connected by a universal cord and performs image processing of an in-vivo image captured by an image sensor, and a display device that is connected to the processing device and displays an in-vivo image subjected to image processing, Is provided.

  In the endoscope system described above, various control signals such as a clock signal and a synchronization signal for driving the image sensor are transmitted from the processing device to the image sensor via the universal code. In such an endoscope system, in order to prevent an increase in the number of signal lines in the universal code, two signals are transmitted from a clock signal and a transmission signal obtained by modulating serial data for driving the image sensor in accordance with the clock signal. A technique of transmitting to an image sensor with a line is known (see Patent Document 1).

JP 2012-10160 A

  However, in Patent Document 1 described above, since the clock signal and the transmission signal are transmitted through different signal lines, the clock signal and the transmission signal may be disturbed due to disturbance noise or the like, which may prevent stable signal transmission. there were. On the other hand, in order to prevent the influence of disturbance noise, it is conceivable to transmit the clock signal and the transmission signal by a differential method, but in this case, the number of signal lines increases by the number of signals transmitted by the differential method. However, there is a problem that the diameter of the insertion portion in the endoscope cannot be reduced and the apparatus becomes complicated.

  The present invention has been made in view of the above, and an object of the present invention is to provide a communication system, a transmission device, and a reception device that can perform stable signal transmission with a simple configuration.

  In order to solve the above-described problems and achieve the object, a communication system according to the present invention is a communication system including a transmission device and a reception device capable of communicating via a transmission cable, and the transmission device includes: A clock signal generation unit that generates a clock signal, a synchronization signal generation unit that generates a synchronization signal based on the clock signal, and a modulation signal is generated by modulating one of the clock signal and the synchronization signal And a modulation unit that transmits the modulated signal and the other signal via the transmission cable, and the receiving device receives the modulated signal and the other signal via the transmission cable, And an extraction unit that extracts a signal necessary for the operation of the communication system from the modulated signal.

  Further, in the communication system according to the present invention, in the above invention, the extraction unit is necessary for the operation from the modulation signal based on a difference between the modulation signal and one of the clock signal and the synchronization signal. A signal is extracted.

  Further, the communication system according to the present invention is characterized in that, in the above-mentioned invention, the modulation unit modulates the synchronization signal based on the clock signal.

  In the communication system according to the present invention, the modulation unit modulates the clock signal based on the synchronization signal.

  Further, in the communication system according to the present invention, in the above invention, the receiving device is an endoscope that can be inserted into a body cavity of a subject, and the transmitting device is detachably connected to the endoscope, It is a control device for controlling the endoscope.

  In the communication system according to the present invention as set forth in the invention described above, the receiving device further includes an image sensor that images a subject and generates image data of the subject, and the extraction unit drives the image sensor. A signal necessary for the extraction is extracted from the modulated signal.

  A transmitting apparatus according to the present invention is a transmitting apparatus that transmits a signal to a receiving apparatus of a communication system that transmits a signal via a transmission cable, the clock signal generating unit generating a clock signal, and the clock signal A synchronization signal generation unit that generates a synchronization signal, modulates one of the clock signal and the synchronization signal to generate a modulation signal, and receives the modulation signal and the other via the transmission cable. And a modulation unit for transmission to the apparatus.

  A receiving apparatus according to the present invention is a receiving apparatus that receives a signal transmitted from a transmitting apparatus of a communication system that transmits a signal via a transmission cable, and that receives a clock signal and a synchronization signal via the transmission cable. An extraction unit is provided that receives a modulated signal, one of which is modulated and the other, and extracts a signal necessary for the operation of the receiving apparatus from the modulated signal.

  According to the present invention, there is an effect that stable signal transmission can be performed with a simple configuration.

FIG. 1 is a diagram showing a schematic configuration of an endoscope system according to Embodiment 1 of the present invention. FIG. 2 is a block diagram showing a functional configuration of a main part of the endoscope system according to Embodiment 1 of the present invention. FIG. 3 is a circuit diagram schematically showing the configuration of the modulation unit of the endoscope system according to Embodiment 1 of the present invention. FIG. 4 is a circuit diagram schematically showing the configuration of the extraction unit of the endoscope system according to Embodiment 1 of the present invention. FIG. 5 is a timing chart showing operations of the extraction unit and the modulation unit of the endoscope system according to Embodiment 1 of the present invention. FIG. 6 is a circuit diagram schematically showing the configuration of the modulation unit of the endoscope system according to Embodiment 2 of the present invention. FIG. 7 is a circuit diagram schematically showing the configuration of the extraction unit of the endoscope system according to Embodiment 2 of the present invention. FIG. 8 is a timing chart showing operations of the extraction unit and the modulation unit of the endoscope system according to Embodiment 2 of the present invention.

  Hereinafter, modes for carrying out the present invention (hereinafter referred to as “embodiments”) will be described. In the present embodiment, a medical endoscope system that captures and displays an image of a body cavity of a subject such as a patient as an imaging system will be described as an example. The present invention is not limited to the following embodiments. Furthermore, in the description of the drawings, the same portions will be described with the same reference numerals.

(Embodiment 1)
FIG. 1 is a diagram showing a schematic configuration of an endoscope system according to Embodiment 1 of the present invention. FIG. 2 is a block diagram showing a functional configuration of a main part of the endoscope system according to Embodiment 1 of the present invention.

  An endoscope system 1 shown in FIGS. 1 and 2 includes an endoscope 2 that captures an in-vivo image of a subject by inserting a tip portion into the body cavity of the subject, and illumination that is emitted from the tip of the endoscope. A light source device 3 that generates light, a processing device 4 (control device) that performs predetermined image processing on an in-vivo image captured by the endoscope 2 and comprehensively controls the operation of the entire endoscope system 1; And a display device 5 that displays the in-vivo image subjected to image processing by the processing device 4. In the first embodiment, the endoscope 2 functions as a receiving device, and the processing device 4 functions as a transmitting device.

  First, the configuration of the endoscope 2 will be described. The endoscope 2 includes an insertion portion 21 having an elongated shape having flexibility, an operation portion 22 that is connected to a proximal end side of the insertion portion 21 and receives input of various operation signals, and an insertion portion from the operation portion 22. And a universal cord 23 that includes various cables that extend in a direction different from the direction in which 21 extends and connect to the light source device 3 and the processing device 4.

  The insertion unit 21 includes a distal end portion 24 including an imaging element 244 (imaging device) in which pixels that generate signals by receiving light and performing photoelectric conversion are arranged in a two-dimensional manner, and a plurality of bending pieces. The bendable bending portion 25 is connected to the proximal end side of the bending portion 25 and has a long flexible tube portion 26 having flexibility.

  The distal end portion 24 includes a light guide 241, an illumination lens 242, an optical system 243, an image sensor 244, an analog front end portion 245 (hereinafter referred to as “AFE portion 245”), a P / S conversion portion 246, An extraction unit 247, a timing generator unit 248 (hereinafter referred to as “TG unit 248”), and an imaging control unit 249 are included.

  The light guide 241 is configured using glass fiber or the like, and forms a light guide path for light emitted from the light source device 3. The illumination lens 242 is provided at the tip of the light guide 241 and diverges the light guided by the light guide 241 toward the subject.

  The optical system 243 is configured by using one or a plurality of lenses, a prism, and the like, and has an optical zoom function for changing the angle of view and a focus function for changing the focus.

  The image sensor 244 photoelectrically converts light from the optical system 243 to generate an electrical signal as an image signal. The image sensor 244 is configured using an image sensor such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS). The image sensor 244 is provided at an imaging position where the optical system 243 forms a subject image. The imaging element 244 generates an image signal according to the signal input from the TG unit 248 and the clock signal input from the processing device 4 under the control of the imaging control unit 249.

  The AFE unit 245 reduces the noise component included in the image signal input from the image sensor 244 and adjusts the amplification factor of the image signal to maintain a constant output level and the image signal. A / D conversion processing for A / D conversion is performed, and the result is output to the P / S conversion unit 246.

  The P / S conversion unit 246 performs parallel / serial conversion on the digital image signal input from the AFE unit 245 and outputs the digital image signal to the processing device 4.

  The extraction unit 247 receives the clock signal and the modulation signal input from the processing device 4 and extracts a signal necessary for the operation of the image sensor 244 from the received modulation signal. Specifically, the extraction unit 247 extracts at least a synchronization signal as a signal necessary for the operation of the image sensor 244 from the modulation signal based on the difference (voltage difference) between the clock signal and the modulation signal. The extraction unit 247 outputs the clock signal to the image sensor 244, the AFE unit 245, the P / S conversion unit 246, the TG unit 248, and the imaging control unit 249. The detailed configuration of the extraction unit 247 will be described later.

  The TG unit 248 generates various signal processing pulses for driving the imaging element 244 and the imaging control unit 249, respectively. The TG unit 248 outputs a pulse signal to the imaging element 244 and the imaging control unit 249.

  The imaging control unit 249 controls imaging of the image sensor 244. The imaging control unit 249 is configured using a CPU (Central Processing Unit), a register that records various programs, and the like.

  The operation section 22 includes a bending knob 221 that bends the bending section 25 in the vertical direction and the left-right direction, a treatment instrument insertion section 222 that inserts a treatment instrument such as a biological forceps, an electric knife, and a test probe into the body cavity of the subject. In addition to the processing device 4 and the light source device 3, it has a plurality of switches 223 which are operation input units for inputting operation instruction signals of peripheral devices such as air supply means, water supply means, and screen display control. The treatment tool inserted from the treatment tool insertion portion 222 is exposed from the opening (not shown) via the treatment tool channel (not shown) of the distal end portion 24.

  The universal cord 23 includes at least a light guide 241 and a collective cable 250 in which one or a plurality of signal lines are collected. The collective cable 250 includes at least a signal for transmitting a clock signal and a modulation signal output from a modulation unit 409 of the processing device 4 to be described later, and a signal for transmitting an image signal.

  Next, the configuration of the light source device 3 will be described. The light source device 3 includes an illumination unit 31 and an illumination control unit 32.

  Under the control of the illumination control unit 32, the illumination unit 31 sequentially switches and emits a plurality of illumination lights having different wavelength bands from the subject (subject). The illumination unit 31 includes a light source unit 31a, a light source driver 31b, a rotary filter 31c, a drive unit 31d, and a drive driver 31e.

  The light source unit 31a is configured using a white LED and one or a plurality of lenses, and emits white light to the rotary filter 31c under the control of the light source driver 31b. The white light generated by the light source unit 31a is emitted from the tip of the tip part 24 toward the subject via the rotary filter 31c and the light guide 241. The light source unit 31a may be composed of a red LED, a green LED, and a blue LED, and the light source driver 31b may sequentially emit red light, green light, or blue light by supplying current to each LED. Good. Alternatively, the white LED, the red LED, the green LED, and the blue LED may emit light simultaneously, or the subject may be irradiated with white light using a discharge lamp such as a xenon lamp to acquire an image. .

  The light source driver 31b causes the light source unit 31a to emit white light by supplying a current to the light source unit 31a under the control of the illumination control unit 32.

  The rotary filter 31c is disposed on the optical path of white light emitted from the light source unit 31a, and rotates to transmit only light in a predetermined wavelength band among the white light emitted from the light source unit 31a. Specifically, the rotary filter 31c includes a red filter 311, a green filter 312 and a blue filter 313 that transmit light having respective wavelength bands of red light (R), green light (G), and blue light (B). . The rotating filter 31c sequentially transmits light in the red, green, and blue wavelength bands (for example, red: 600 nm to 700 nm, green: 500 nm to 600 nm, blue: 400 nm to 500 nm) by rotating. As a result, the white light (W illumination) emitted from the light source unit 31a is converted into any one of red light (R illumination), green light (G illumination), and blue light (B illumination) with a narrow band. Can be sequentially emitted (surface sequential method).

  The drive unit 31d is configured using a stepping motor, a DC motor, or the like, and rotates the rotary filter 31c.

  The drive driver 31e supplies a predetermined current to the drive unit 31d under the control of the illumination control unit 32.

  Under the control of the control unit 410, the illumination control unit 32 causes the light source unit 31a to emit white light at a predetermined period.

  Next, the configuration of the processing device 4 will be described. The processing device 4 includes an S / P conversion unit 401, an image processing unit 402, a brightness detection unit 403, a dimming unit 404, an input unit 405, a recording unit 406, a reference clock generation unit 407, and a synchronization unit. A signal generation unit 408, a modulation unit 409, and a control unit 410 are provided.

  The S / P conversion unit 401 performs parallel / serial conversion on the image signal input from the P / S conversion unit 246 and outputs the image signal to the image processing unit 402. The image signal includes image data, correction parameters for correcting the image sensor 244, and the like.

  The image processing unit 402 generates an in-vivo image displayed by the display device 5 based on the image signal input from the S / P conversion unit 401 and outputs the generated in-vivo image to the display device 5. The image processing unit 402 performs predetermined image processing on the image signal to generate an in-vivo image. Here, the image processing includes synchronization processing, optical black reduction processing, white balance adjustment processing, color matrix calculation processing, gamma correction processing, color reproduction processing, edge enhancement processing, format conversion processing, and the like. Further, the image processing unit 402 outputs the image signal input from the S / P conversion unit 401 to the control unit 410 or the brightness detection unit 403.

  The brightness detection unit 403 detects the brightness level corresponding to each image based on the RGB image information included in the image signal input from the image processing unit 402, and the detected brightness level is provided inside. The data is recorded in the memory and output to the control unit 410.

  Based on the brightness level detected by the brightness detection unit 403 under the control of the control unit 410, the light control unit 404 sets light emission conditions such as the amount of light generated by the light source device 3 and the light emission timing. The dimming signal including the light emission condition is output to the light source device 3.

  The input unit 405 receives input of various signals such as an operation instruction signal that instructs the operation of the endoscope system 1. The input unit 405 is configured using a switch or the like.

  The recording unit 406 records data including various programs for operating the endoscope system 1 and various parameters necessary for the operation of the endoscope system 1. The recording unit 406 records the identification information of the processing device 4. Here, the identification information includes unique information (ID) of the processing device 4, year, specification information, transmission method, transmission rate, and the like.

  The reference clock generation unit 407 generates a clock signal that serves as a reference for the operation of each component of the endoscope system 1 and supplies the clock signal to each component of the endoscope system 1. In the first embodiment, the reference clock generation unit 407 functions as a clock signal generation unit.

  The synchronization signal generation unit 408 generates a synchronization signal including at least a vertical synchronization signal based on the clock signal input from the reference clock generation unit 407, and the TG unit via the modulation unit 409, the collective cable 250, and the extraction unit 247 The data is output to H.248 and also output to the image processing unit 402.

  The modulation unit 409 modulates the synchronization signal input from the synchronization signal generation unit 408, and outputs the modulated modulation signal (Diff_s) and the clock signal (Diff_c) input from the reference clock generation unit 407 to the extraction unit 247. Specifically, the modulation unit 409 outputs a modulation signal obtained by modulating the synchronization signal based on the clock signal. For example, the modulation unit 409 generates a modulation signal obtained by modulating the synchronization signal based on the difference between the clock signal and the synchronization signal, and outputs the modulation signal.

  The control unit 410 performs drive control of each component including the image sensor 244 and the light source device 3, input / output control of information with respect to each component, and the like. The control unit 410 outputs setting data for imaging control recorded in the recording unit 406, for example, image address information to be read, to the imaging control unit 249 via the collective cable 250.

  Next, the display device 5 will be described. The display device 5 displays an in-vivo image corresponding to the image signal input from the processing device 4 via the video cable. The display device 5 is configured using liquid crystal, organic EL (Electro Luminescence), or the like.

  Next, the configuration and operation of the modulation unit 409 and the extraction unit 247 described above will be described. FIG. 3 is a circuit diagram schematically showing the configuration of the modulation unit 409.

  As shown in FIG. 3, the modulation unit 409 includes a latch circuit 409a and an AND circuit 409b.

  Based on the clock signal (CLK) input from the reference clock generation unit 407, the latch circuit 409a outputs the synchronization signal (SYNC) input from the synchronization signal generation unit 408 to the AND circuit 409b. Specifically, the latch circuit 409a outputs the synchronization signal input from the synchronization signal generation unit 408 to the AND circuit 409b based on the rising edge (edge) of the clock signal input from the reference clock generation unit 407.

  The AND circuit 409b modulates the synchronization signal input from the latch circuit 409a based on the clock signal input from the reference clock generation unit 407, and outputs the modulated modulation signal (Diff_s) to the extraction unit 247. Specifically, the AND circuit 409b modulates the synchronization signal based on the difference between the clock signal and the synchronization signal to generate a modulation signal, and outputs the modulation signal to the extraction unit 247. For example, the AND circuit 409b generates a modulation signal by performing modulation such that the timing at which the difference between the clock signal and the synchronization signal is high and the timing at which the clock signal and the synchronization signal are equal to Low are performed on the synchronization signal And output to the extraction unit 247.

  Next, the configuration of the extraction unit 247 will be described. FIG. 4 is a circuit diagram schematically showing the configuration of the extraction unit 247. As shown in FIG.

  As shown in FIG. 4, the extraction unit 247 includes a differential amplifier circuit 247a, a differential amplifier circuit 247b, a comparison circuit 247c, a comparison circuit 247d, and a latch circuit 247e.

  In the differential amplifier circuit 247a, the clock signal (Diff_c) is input from the modulation unit 409 to the non-inverting input terminal (+), and the modulation signal (Diff_s) is input from the modulation unit 409 to the inverting input terminal (−). The differential amplifier circuit 247a calculates a difference (Diff_c-Diff_s) between the clock signal and the modulated signal input from the modulation unit 409, and compares the difference signal (C-S) obtained by multiplying the difference by a constant coefficient. To 247c.

  In the differential amplifier circuit 247b, the modulation signal (Diff_s) is input from the modulation unit 409 to the non-inverting input terminal (+), and the clock signal (Diff_c) is input from the modulation unit 409 to the inverting input terminal (−). The differential amplifier circuit 247b calculates a difference (Diff_s-Diff_c) between the modulation signal input from the modulation unit 409 and the clock signal, and compares the differential signal (S-C) obtained by multiplying the difference by a constant coefficient. Output to 247d.

  In the comparison circuit 247c, the differential signal (C-S) input from the differential amplifier circuit 247b is input to the non-inverting input terminal (+), and the reference voltage is input to the inverting input terminal (-). The comparison circuit 247c compares the differential signal with the reference voltage, and compares the comparison signal indicating the comparison result with the latch circuit 247e, the imaging device 244, the AFE unit 245, the P / S conversion unit 246, the TG unit 248, and the imaging control unit 249. Output to.

  In the comparison circuit 247d, the differential signal (C−S) input from the differential amplifier circuit 247a is input to the non-inverting input terminal (+), and the reference voltage is input to the inverting input terminal (−). The comparison circuit 247d compares the differential signal with the reference voltage and outputs a comparison signal indicating the comparison result to the latch circuit 247e.

  The latch circuit 247e extracts a signal (synchronization signal) necessary for the operation of the image sensor 244 based on the comparison signal input from the comparison circuit 247c and the comparison signal input from the comparison circuit 247d, and the extracted signal (SYNC) is output to the TG unit 248. Specifically, the latch circuit 247e extracts a synchronization signal necessary for the operation of the image sensor 244 based on the difference between the comparison signal (C−S) and the comparison signal (S−C). The data is output to the TG unit 248.

  The operation timing of the extraction unit 247 and the modulation unit 409 configured as described above will be described. FIG. 5 is a timing chart showing operations of the extraction unit 247 and the modulation unit 409. 5A shows the clock signal (CLK), FIG. 5B shows the synchronization signal (SYNC), FIG. 5C shows Diff_c, and FIG. 5D shows Diff_s. FIG. 5E shows the operation of the extraction unit 247.

  As shown in FIG. 5, the modulation unit 409 does not modulate the clock signal and outputs it to the extraction unit 247 (see FIG. 5C), and based on the difference between the clock signal and the synchronization signal, And the modulated signal (see FIG. 5D) is output to the extraction unit 247.

  The extraction unit 247 extracts a synchronization signal necessary for the operation of the image sensor 244 from the modulation signal based on the difference between the clock signal and the modulation signal, and outputs the synchronization signal to the TG unit 248. Specifically, the extraction unit 247 extracts the synchronization signal from the modulation signal using the reference voltage. For example, when the reference voltage is 3.3 V, the extraction unit 247 extracts a signal of +1.65 V or more as a clock signal with respect to the modulation signal, and extracts a modulation signal of −1.65 V or more as a synchronization signal. (See FIG. 5 (e)).

  According to Embodiment 1 of the present invention described above, the modulation unit 409 transmits the modulation signal and the clock signal obtained by modulating the synchronization signal, and the extraction unit 247 extracts the synchronization signal from the modulation signal. Thus, stable signal transmission can be performed.

  Further, according to the first embodiment of the present invention, even when a noise component is superimposed on each of the clock signal and the synchronization signal transmitted from the processing device 4 to the endoscope 2, the voltage difference between the two signals. Since it transmits, noise tolerance can be improved.

(Embodiment 2)
Next, a second embodiment of the present invention will be described. In the first embodiment described above, the clock signal is not modulated and the synchronization signal is modulated. In the second embodiment, the clock signal is modulated without modulating the synchronization signal. For this reason, only the configurations of the modulation unit and the extraction unit in the endoscope system 1 according to the first embodiment described above are different. Therefore, in the following, after describing the configuration of the modulation unit and the extraction unit of the endoscope system according to the second embodiment, the operation of the modulation unit and the extraction unit will be described. In addition, the same code | symbol is attached | subjected to the structure same as the endoscope system 1 which concerns on Embodiment 1 mentioned above, and description is abbreviate | omitted.

  First, the configuration of the modulation unit will be described. FIG. 6 is a circuit diagram schematically showing the configuration of the modulation unit.

  As illustrated in FIG. 6, the modulation unit 501 includes a latch circuit 409a and an XOR circuit 501a.

  The XOR circuit 501a modulates the clock signal (CLK) input from the reference clock generation unit 407 based on the synchronization signal (SYNC) input from the latch circuit 409a, and extracts the modulated signal (Diff_s) that has been modulated. Output (supply) to 502. Specifically, the XOR circuit 501 a generates a modulation signal obtained by modulating the clock signal based on the difference between the clock signal and the synchronization signal, and outputs the modulation signal to the extraction unit 502. For example, the XOR circuit 501a generates a modulation signal by performing a modulation on the clock signal such that the timing at which the difference between the clock signal and the synchronization signal is High and the timing at which the clock signal and the synchronization signal are equal to Low. And output to the extraction unit 502.

  Next, the configuration of the extraction unit 502 will be described. FIG. 7 is a circuit diagram schematically showing the configuration of the extraction unit 502.

  As illustrated in FIG. 7, the extraction unit 502 includes a differential amplifier circuit 247a, a differential amplifier circuit 247b, a comparison circuit 247c, a comparison circuit 247d, a latch circuit 247e, and an AND circuit 247f.

  In the differential amplifier circuit 247a, the clock signal (Diff_c) is input from the modulation unit 409 to the non-inverting input terminal (+), and the modulation signal (Diff_s) is input from the modulation unit 409 to the inverting input terminal (−). The differential amplifier circuit 247a calculates a difference (Diff_c-Diff_s) between the clock signal and the modulated signal input from the modulation unit 409, and compares the difference signal (C-S) obtained by multiplying the difference by a constant coefficient. To 247c.

  In the differential amplifier circuit 247b, the modulation signal (Diff_s) is input from the modulation unit 409 to the non-inverting input terminal (+), and the clock signal (Diff_c) is input from the modulation unit 409 to the inverting input terminal (−). The differential amplifier circuit 247b calculates a difference (Diff_s-Diff_c) between the modulation signal input from the modulation unit 409 and the clock signal, and compares the differential signal (S-C) obtained by multiplying the difference by a constant coefficient. Output to 247d.

  In the comparison circuit 247c, the differential signal (C-S) input from the differential amplifier circuit 247b is input to the non-inverting input terminal (+), and the reference voltage is input to the inverting input terminal (-). The comparison circuit 247c compares the differential signal with the reference voltage and outputs a comparison signal indicating the comparison result to the AND circuit 247f.

  In the comparison circuit 247d, the differential signal (C−S) input from the differential amplifier circuit 247a is input to the non-inverting input terminal (+), and the reference voltage is input to the inverting input terminal (−). The comparison circuit 247d compares the differential signal with the reference voltage and outputs a comparison signal indicating the comparison result to the AND circuit 247f.

  The AND circuit 247f restores (extracts) the clock signal based on the comparison signal input from the comparison circuit 247c or the comparison signal input from the comparison circuit 247d, and the clock signal (CLK) is latched by the latch circuit 247e, the image sensor. 244, AFE unit 245, P / S conversion unit 246, TG unit 248, and imaging control unit 249.

  Based on the clock signal input from the AND circuit 247f, the latch circuit 247e extracts a signal (synchronization signal) necessary for the operation of the image sensor 244 from the comparison signal input from the comparison circuit 247d, and this extracted signal ( SYNC) is output to the TG unit 248. Specifically, the latch circuit 247 e extracts a synchronization signal necessary for the operation of the image sensor 244 from the comparison signal based on the difference between the clock signal and the comparison signal, and outputs this synchronization signal to the TG unit 248.

  The operation timing of the modulation unit 501 and the extraction unit 502 configured as described above will be described. FIG. 8 is a timing chart showing operations of the modulation unit 501 and the extraction unit 502. 8, FIG. 8A shows the clock signal (CLK), FIG. 8B shows the synchronization signal (SYNC), FIG. 8C shows Diff_c, and FIG. 8D shows Diff_s. 8E and 8F show the operation of the extraction unit 502.

  As shown in FIG. 8, the modulation unit 501 does not modulate the synchronization signal and outputs it to the extraction unit 502 (see FIG. 8D), and based on the difference between the clock signal and the synchronization signal, Is modulated and the modulated signal (see FIG. 8C) is output to the extraction unit 502.

  The extraction unit 502 extracts a clock signal necessary for the operation of the image sensor 244 from the modulation signal based on the difference between the synchronization signal and the modulation signal, and outputs the clock signal to the TG unit 248. Specifically, the extraction unit 502 extracts a clock signal from the modulation signal using the reference voltage. For example, when the reference voltage is 3.3 V, the extraction unit 502 extracts a signal of 1.65 V or more as a clock signal (see 8 (e) and (f)).

  According to the second embodiment of the present invention described above, stable signal transmission can be performed with a simple configuration.

  Further, according to the second embodiment of the present invention, even when a noise component is superimposed on each of the clock signal and the synchronization signal transmitted from the processing device 4 to the endoscope 2, the voltage difference between the two signals is used. Since it transmits, noise tolerance can be improved.

  In the present invention, the communication system is described as an endoscope system in which the transmission side is a processing device and the reception side is an endoscope. However, for example, even if the transmission side is an endoscope and the reception side is an endoscope system of a processing device. The present invention can also be applied to a microscope system in which an imaging device and a treatment device communicate with each other via a transmission cable.

  In the present invention, an imaging device is provided in the endoscope, and the extraction unit extracts at least a synchronization signal or a clock signal for driving the imaging device from the modulation signal. (Sonic transducer) may be provided, and the extraction unit may extract a drive signal for driving the ultrasonic element. Of course, the extraction unit may extract a setting signal indicating a setting of a pixel address or the like for reading an image signal from the image sensor.

  As described above, the present invention can include various embodiments not described herein, and various design changes and the like can be made within the scope of the technical idea specified by the claims. Is possible.

DESCRIPTION OF SYMBOLS 1 Endoscope system 2 Endoscope 3 Light source device 4 Processing apparatus 5 Display apparatus 21 Insertion part 22 Operation part 23 Universal code 24 Tip part 25 Bending part 26 Flexible tube part 31 Illumination part 32 Illumination control part 241 Light guide 242 Illumination Lens 243 Optical system 244 Image sensor 245 Analog front end unit 246 P / S conversion unit 247,502 Extraction unit 247a, 247b Differential amplification circuit 247c, 247d Comparison circuit 247e Latch circuit 247f AND circuit 248 Timing generator unit 249 Imaging control unit 401 S / P conversion unit 402 Image processing unit 403 Brightness detection unit 404 Dimming unit 405 Input unit 406 Recording unit 407 Reference clock generation unit 408 Synchronization signal generation unit 409, 501 Modulation unit 409a Latch circuit 409b AND circuit 410 Control unit 5 1a XOR circuit

Claims (3)

An endoscope system comprising an endoscope that can be inserted into a body cavity of a subject , and a control device that controls the endoscope via a transmission cable,
The controller is
A clock signal generator for generating a clock signal;
A synchronization signal generating unit that generates a synchronization signal based on the clock signal;
Based on the difference between the clock signal and the synchronization signal, a modulation signal is generated by modulating one of the clock signal and the synchronization signal, and the modulation signal and the other signal are transmitted to the transmission cable. A modulation unit for transmitting via
With
The endoscope is
An insertion part that can be inserted into the body cavity of the subject;
An image sensor provided at a distal end of the insertion portion;
The modulation signal and the other signal are received via the transmission cable, and the imaging element is driven from the modulation signal based on a difference between the one of the clock signal and the synchronization signal and the modulation signal. An extraction unit for extracting a signal necessary for
An endoscope system comprising: The endoscope system according to claim 1 , wherein the modulation unit modulates the synchronization signal based on the clock signal. The endoscope system according to claim 1 , wherein the modulation unit modulates the clock signal based on the synchronization signal.

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