JP2005103325A - Electronic endoscope device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic endoscope device which can process signals at high speed by using a simple circuit structure. <P>SOLUTION: This electronic endoscope device is equipped with: a plurality of analog signal processing means which respectively receive a plurality of imaging signals from a plurality of solid state imaging devices which can output imaging signals and apply prescribed analog signal processing to each of the imaging signals; a plurality of A/D conversion means which respectively apply A/D conversion to a plurality of analog signals which have been subjected to analog signal processing by the plurality of analog signal processing means; and a digital signal synthesizing means which applies prescribed synthesis processing to a plurality of A/D-converted digital signals which have been respectively subjected to A/D conversion by the plurality of A/D converting means. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electronic endoscope apparatus, and more particularly to an electronic endoscope apparatus characterized by a control portion of a drive signal of a solid-state image sensor.

  In recent years, an insertion part is inserted into a body cavity, and illumination light is irradiated to the observation part at the distal end of the insertion part by illumination light transmission means such as a light guide fiber bundle to obtain an image of the observation part, and the observation part is observed and treated. Endoscope devices are widely used.

  One of the endoscope apparatuses is provided with a solid-state imaging device, for example, a CCD at the distal end of the insertion portion, and an image of an observation site is formed on an imaging surface by an objective optical system and converted into an electrical signal. Thus, there is an electronic endoscope apparatus that can display an image of an observation site on a monitor or the like and store it as image data in an information recording apparatus or the like.

  In the electronic endoscope apparatus as described above, an electronic endoscope apparatus having a solid-state imaging device capable of outputting a plurality of imaging signals is known. However, in the apparatus, signal processing is performed at higher speed with a simpler circuit configuration. Was desired to perform.

  The present invention has been made in view of the above circumstances, and in an electronic endoscope apparatus having a solid-state imaging device capable of outputting a plurality of imaging signals, after combining a plurality of imaging signals at a higher speed with a simple circuit configuration. An object of the present invention is to provide an electronic endoscope apparatus capable of executing the signal processing.

  An electronic endoscope apparatus according to a first aspect of the present invention includes an endoscope provided with a solid-state image pickup device capable of outputting a plurality of image pickup signals at a tip thereof, and an image pickup signal received from the solid-state image pickup device. And a camera control unit having signal processing means for performing predetermined signal processing. The signal processing means receives each of a plurality of imaging signals from the solid-state imaging device, and each imaging A plurality of analog signal processing means for performing predetermined analog signal processing on each of the signals, and a plurality of A for A / D converting each of the plurality of analog processing signals subjected to the analog signal processing in the plurality of analog signal processing means / D conversion means and a digital signal synthesizing unit for performing a predetermined synthesis process on the plurality of digital signals respectively A / D converted by the plurality of A / D conversion means When provided with, before and after the combining process in the digital signal synthesis means, the processing speed of the post-synthesis is characterized by being faster the processing speed before synthesis.

  A second electronic endoscope apparatus according to the present invention includes an endoscope provided with a solid-state imaging device capable of outputting a plurality of image signals that can be simultaneously read, a storage unit capable of storing a predetermined video signal, An electronic endoscope apparatus comprising: a camera control unit having a signal processing unit that receives an imaging signal of the solid-state imaging element and performs predetermined signal processing on the imaging signal. A first signal processing unit that receives the image signals simultaneously read from the image sensor, performs a predetermined process on each of the image signals, and then writes the signal to a predetermined storage unit; and a predetermined signal from the storage unit The second signal processing means for reading the video signal, and the imaging function control means for controlling the imaging function based on the signal from the first signal processing means.

  According to a third electronic endoscope apparatus of the present invention, in the second electronic endoscope apparatus, the imaging function control unit controls a γ correction function and a white balance function.

  According to the present invention, in an electronic endoscope apparatus having a solid-state imaging device capable of outputting a plurality of imaging signals, signal processing after combining the plurality of imaging signals can be executed at a higher speed with a simple circuit configuration. .

  Embodiments of the present invention will be described below with reference to the drawings.

  1 to 4 relate to the first embodiment of the present invention. FIG. 1 is a block diagram showing the configuration of the electronic endoscope apparatus. FIG. 2 is a block diagram showing the configuration of the patient side circuit of FIG. 3 is a timing chart for explaining the operation of the electronic endoscope apparatus of FIG.

(Constitution)
As shown in FIG. 1, an electronic endoscope apparatus 1 according to the first embodiment includes an electronic endoscope 2 that observes the inside of a body cavity, and a camera control unit that processes signals from the electronic endoscope 2 ( (Hereinafter referred to as CCU) 3, a light source device 4 that supplies illumination light for illuminating the inside of the body cavity to the electronic endoscope 2, and a standard format TV signal (RGB, Y / C, composite video) from the CCU 3 And a TV monitor 5 for displaying an image.

  The electronic endoscope 2 has a solid-state imaging device, for example, a CCD 10 and a light guide (not shown) at the tip.

  The CCU 3 receives a signal from the patient side circuit 12 for driving the CCD 10, an isolation element 14 for isolating the output of the patient side circuit 12, and a signal from the patient side circuit 12 isolated by the isolation element 14. It comprises a secondary circuit 16 (signal processing means) for processing and performing various video processing.

  The secondary circuit 16 includes an analog processing unit 18 that processes an analog signal from the patient-side circuit 12 via the isolation element 14, and an A / D conversion that converts the analog signal output from the analog processing unit 18 into a digital signal. Unit 20, a digital processing unit 22 that processes a digital signal from the A / D conversion unit 20, and a D / A conversion unit 24 that converts the digital signal output from the digital processing unit 22 into an analog signal. Yes.

  In the electronic endoscope 2, the CCD 10 is driven by a patient-side circuit 12, and illumination light supplied from the light source device 4 is transmitted through a light guide (not shown), and a subject (see FIG. (Not shown). The electronic endoscope 2 converts the subject image formed on the CCD 10 by a lens unit (not shown) into an electrical signal and outputs it to the CCU 3 as image information.

  In the CCU 3, the image information output from the CCD 10 is amplified by the patient-side circuit 12 and input to the secondary circuit 16 via the isolation element 14.

  In the secondary circuit 16, the analog processing unit 18 performs processing such as control of synchronization signals between the patient-side circuit 12 and the secondary circuit 16, signal amplification, and noise removal. The image information processed by the analog processing unit 18 is converted into a digital signal by the A / D conversion unit 20 and input to the digital processing unit 22. The digital processing unit 22 performs digital processing such as gamma correction, signal synthesis, and enhancement processing, and converts it into a standard format TV signal. The TV signal is converted into an analog signal by the D / A converter 24, and the subject image is displayed as a video on the TV monitor 5.

  In the present embodiment, the CCD 10 provided at the tip of the electronic endoscope 2 is a two-line readout CCD.

  As shown in FIG. 2, the patient side circuit 12 is programmable and outputs a CCD drive timing signal to the CCD driver 30 (drive signal generating means) for driving the CCD 10 and the CCD drive timing signal. An FPGA (Field Programmable Gate Array) 32 (drive signal control means), which is a programmable element having a superimposing means for superimposing a synchronization signal, which will be described later, a data ROM 34 for programming the FPGA 32, and detection of the type of CCD and connection status A CCD detection circuit 36 (connection detection means) that performs matching of a cable that transmits a CCD drive signal to the CCD 10, and a cable matching circuit 38 that is adapted to the CCD 10 based on a selection signal output from the FPGA 14. Select cable matchon Switching circuit 40, preamplifier section 42 that amplifies the electrical signal read from CCD 10, CCD power supply circuit 44 that limits the power supply of power supplied to CCD 10, and power supply to CCD power supply circuit 44 And a main power source 46.

  The CCD driver 30 includes a horizontal transfer drive pulse generation circuit 50 and a vertical transfer drive pulse generation circuit 52 that transfer charges accumulated in the CCD 10 and an anti-blooming pulse generation circuit 54 that suppresses blooming.

(Function)
Next, the operation of the electronic endoscope apparatus 1 of the present embodiment configured as described above will be described.

  First, a method for detecting the synchronization between the patient-side circuit 12 and the secondary circuit 16 in the electronic endoscope apparatus 1 will be described with reference to the timing chart of FIG.

  Here, in FIG. 3, an enlarged view of the 1L timing chart of the CCD horizontal transfer pulse during the video signal reading period is shown as φA, and an enlarged view of the CCD output at this time is shown as TA. Further, an enlarged view of the 1L timing chart of the CCD horizontal transfer pulse at the end of 1V and an enlarged view of the CCD output at that time are shown in φB and TB, respectively, as described above. Note that 1V indicates one field period (1/60 s), and 1L indicates approximately 0.5H (1H = 63.5 μs = horizontal scanning period).

  In order to synchronize the patient-side circuit 12 and the secondary circuit 16, the FPGA 32 shifts the phase of 1L at the end of 1V by 180 degrees from the CCD horizontal drive pulse of the other 1L period. As described above, a CCD output whose phase is shifted by 180 degrees from the CCD output of the other 1L period is generated.

  The CCD output is amplified by the preamplifier unit 42, insulated by the isolation element 14, and input to the analog processing unit 18 in the secondary circuit 16 to detect a synchronization signal including a CDS circuit (not shown). The synchronous VRST is detected after the CDS output is detected by the synchronous detector.

  Here, if the phase of the CCD output is shifted by 180 degrees, the polarity of the output is reversed as shown by the CDS output in FIG. In this way, the synchronization signal is superimposed on the electrical signal read from the CCD 10 only for the 1L period at the end of 1V. The patient-side circuit 12 and the secondary circuit 16 are synchronized by resetting the FPGA 32 with the detected synchronous VRST.

  In addition, although not shown in the analog processing unit 18, synchronization detection is performed to detect the presence or absence of synchronization between the PLL unit that compares the phase of the signal output from the patient side circuit 12, and the secondary circuit 16 and the patient side circuit 12. And a signal that can be phase-compared for the entire period so that the secondary circuit 16 can easily synchronize when the synchronization is not achieved by controlling the FPGA 32 based on the detection result by the synchronization detection means. Is superimposed on the CCD drive signal. When synchronization is established, a signal that can be phase-compared for a partial period is superimposed on the CCD drive signal.

  In the electronic endoscope apparatus 1 of the present embodiment, the CCU 3 detects the type of the CCD 10 and the connection state of the electronic endoscope 2 provided with the CCD 10 at the tip by the CCD detection circuit 36 when the power is turned on. Then, based on the detection result of the CCD detection circuit 36, the programmable FPGA 32 in the data ROM 34 is programmed.

  Next, the FPGA 32 programmed based on the type of the CCD 10 outputs a CCD drive timing signal to the CCD driver 30. Here, the CCD drive timing signals are CCD horizontal drive timing signals S1 and S2, vertical transfer drive timing signal S3, and anti-blooming timing signal S4.

  The CCD drive timing signals are amplified by a horizontal transfer drive pulse generation circuit 50, a vertical transfer drive generation circuit 52, and an anti-blooming pulse generation circuit 54, respectively.

  On the other hand, the cable matching switching circuit 40 selects the cable matching circuit 38 suitable for the CCD 10 based on the selection signal for selecting the CCD 10 output from the FPGA 32, shapes the waveform by the cable matching circuit 38, and drives the CCD 10 respectively. CCD horizontal transfer drive pulses, CCD vertical transfer drive pulses, and anti-blooming pulses are generated.

  Here, when the electronic endoscope 2 provided with the CCD 10 at the tip is not connected to the patient side circuit 12, the FPGA 32 outputs the CCD vertical transfer drive timing signal S3 as an output based on the detection result of the CCD detection circuit 36. By stopping, the CCD vertical transfer driving pulse for driving the CCD 10 is stopped. When an electronic endoscope having a different type of CCD at the tip is connected, the FPGA 32 generates a CCD drive timing signal corresponding to the type of CCD based on the CCD detection circuit 36.

  The main power supply 46 supplies power to the CCD power supply circuit 44. The CCD power supply circuit 44 that supplies the CCD 10 uses a variable regulator (not shown) to feed back the output current to the variable regulator, thereby supplying the minimum current that can be driven by the CCD 10.

(effect)
As described above, in the electronic endoscope apparatus 1 according to the present embodiment, when the electronic endoscope 2 provided with the CCD 10 at the distal end is not connected to the patient-side circuit 12, the FPGA 32 displays the detection result of the CCD detection circuit 36. Based on this, the CCD vertical transfer drive timing signal S3, which is the output, is stopped to stop the CCD vertical transfer drive pulse for driving the CCD 10. Therefore, when the electronic endoscope 2 is reconnected to the patient side circuit 12, Prior to supplying power to the CCD 10, no CCD drive signal is supplied to the CCD 10, heat generation of the CCD 10 due to the CCD drive signal can be prevented, and the CCD 10 can be reliably protected.

  As shown in FIG. 2, when the CCD horizontal transfer drive timing signals S1 and S2 output from the FPGA 32 in the patient side circuit 12 have two horizontal transfer drive pulses, if this timing is the same, the patient The preamplifier unit 42, the isolation element 14, the analog processing unit 18, the A / D conversion unit 20, and the digital processing unit 22 in the side circuit 12 are two systems. When two or more CCD horizontal transfer drive pulses are used, the same circuit is used in two or more. The same applies to this case.

  Further, when the electronic endoscope 2 is not connected, the CCU 3 may stop a part of the output of the FPGA 32 and stop only a part of the CCD drive pulses. Alternatively, the CCD driver 30 may be stopped to stop the CCD driving pulse. Further, all the outputs of the power supplied to the CCD 10 may be stopped.

  Further, until the CCD 10 is detected when the electronic endoscope 2 is connected, the output pin from the FPGA 32 may become high impedance, and the output signal may be stopped.

  Further, for the CCD 10 that does not require the anti-blooming pulse, the FPGA 32 may stop the anti-blooming timing signal S4 in accordance with the CCD detection circuit 36, thereby stopping the anti-blooming pulse for driving the CCD 10. Here, the cable matching circuit 38 may be the same circuit for different CCDs 10 when the cable length is constant.

  Further, when white light is projected, the anti-blooming pulse S4 is stopped inside the FPGA 32, and the secondary circuit 16 generates CCD horizontal drive pulses S1 and S2 that are easily synchronized. May be avoided.

  Further, the CCD horizontal drive pulse is binary-driven or ternary-driven during a period in which the PLL unit (not shown) in the analog processing unit 18 compares the phase of the electrical signal output from the patient side circuit 12. May be.

  Further, the anti-blooming pulse has a clocked AC component period and a DC component period of only a DC component. Here, the anti-blooming pulse generation circuit 54 adjusts the alternating current period and the direct current component period separately depending on the type of CCD. However, the anti-blooming pulse generation circuit 54 is configured by a clamp circuit that operates only in the alternating current component period. It may be reduced.

  Further, although the preamplifier unit 42 is configured by a differential amplifier circuit, it may be configured by a single-stage amplifier circuit.

  4 and 5 relate to the second embodiment of the present invention, FIG. 4 is a block diagram showing the configuration of the main part of the electronic endoscope apparatus, and FIG. 5 explains the operation of the signal synthesis unit of FIG. It is explanatory drawing.

  Since the second embodiment is almost the same as the first embodiment, only different points will be described, and the same components are denoted by the same reference numerals and description thereof will be omitted.

(Constitution)
In the second embodiment, the CCD is a two-line readout CCD having two outputs, and this CCD is driven by pulses of the same timing output from the CCD horizontal transfer drive pulse generation circuit to process signals from the CCD. The means for performing the processing is performed by two circuits of the same configuration, and the signals processed by the two circuits of the same structure are digitally combined.

  That is, in the CCU of the electronic endoscope apparatus according to the second embodiment, as shown in FIG. 4, a part of the patient-side circuit 12 and the secondary circuit 16 are the same two system circuit blocks. A pre-process 60a, a second pre-process 60b, a signal synthesizer 62 that synthesizes the digital signals from the two first and second pre-processes 60a, 60b, and a post that processes the signal synthesized by the signal synthesizer 62. Process 64.

  The first preprocess 60a includes a first preamplifier 70a for amplifying one signal from the CCD 10 (not shown), a first isolation element 72a for insulating the patient side circuit 12 and the secondary circuit 16. A first differential amplifier 74a for removing and amplifying the signal, a first CDS circuit 76a for performing correlated double sampling, a first PLL circuit 78a for synchronizing the patient side circuit 12 and the secondary circuit 16, A first analog signal processing unit 80a for performing various analog signal processing, a first A / D conversion unit 82a for converting the output of the first analog signal processing unit 80a into a digital signal, and conversion by the first A / D conversion unit 82a A first digital signal processing unit 84a for performing various digital signal processing on the digital signal thus processed, and a digital signal processed by the first digital signal processing unit 84a And a first gamma correction unit 86a that performs gamma correction to the signal.

  The second preprocess 60b is configured in the same manner as the first preprocess 60a, and includes a second preamplifier 70b for amplifying the other signal from the CCD 10 (not shown), a patient side circuit 12, and a secondary circuit. 16, a second differential amplifier 74 b that performs signal noise removal and amplification, a second CDS circuit 76 b that performs correlated double sampling, a patient-side circuit 12, and a secondary circuit A second PLL circuit 78b for synchronizing 16 signals, a second analog signal processing unit 80b for performing various analog signal processing, and a second A / D conversion for converting the output of the second analog signal processing unit 80b into a digital signal Unit 82b, a second digital signal processing unit 84b that performs various digital signal processing on the digital signal converted by the second A / D conversion unit 82b, And a second gamma correction unit 86b for performing gamma correction to the digital signal processed by the digital signal processing section 84b.

  Outputs from the first preprocess 60 a and the second preprocess 60 b are input to the signal synthesis unit 62. Then, as shown in FIG. 5, the signal combining unit 62 records the first input signal (A) from the first preprocess 60a and the second input signal (B) from the second preprocess 60b. It consists of a one-line memory 88a and a second line memory 88b.

  The signal synthesizer 62 synthesizes one of the outputs from the first preprocess 60a and the second preprocess 60b with a half cycle delay from the other. Then, the signal synthesized by the signal synthesis unit 62 is input to the post process 64.

  The post-process 64 performs mask calculation and enhances a spatial frequency band, a post-stage digital signal processing unit 92 that processes various digital signals via the enhancement unit 90, and an output of the post-stage digital signal processing unit 92 Is converted to an analog signal.

  Other configurations are the same as those of the first embodiment.

(Function)
Here, all the components of the first preprocess 60a and the second preprocess 60b perform the same processing.

  In the first preprocess 60a, first, the first output CCDOUT (A) of the CCD 10 is input from the channel A (hereinafter referred to as CHA), and the CCDOUT (A) is amplified by the first preamplifier 70a. The amplified signal passes through the first isolation element 72a and is input to the first differential amplifier 74a. The first differential amplifier 74a performs signal noise reduction and amplification.

  The signal processed by the first differential amplifier 74a is input to the first CDS circuit 76a and subjected to correlated double sampling. Here, the first PLL circuit 78a synchronizes the patient side circuit 12 and the secondary circuit 16 with respect to the CCD output signal. The signal subjected to correlated double sampling by the first CDS circuit 76a is input to the first analog signal processing unit 80a.

  The first analog signal processing unit 80a performs gain adjustment, clip level adjustment, painting setting, auto gain control (AGC), filtering, clamp processing, and the like.

  The signal that has been subjected to the various processes described above by the first analog signal processing unit 80a is converted into a 10-bit digital signal by the first A / D conversion unit 82a. The converted 10-bit digital signal is subjected to processing such as clamping and white balance in the first digital signal processing unit 84a.

  The 10-bit digital signal processed by the first digital signal processing unit 84a is input to the first gamma correction unit 86a, and the first gamma correction unit 86a corrects the video. At this time, the 10-bit signal is converted into an 8-bit signal. In the first gamma correction unit 86a, since the input is 10 bits, the bit precision of the dark part at the time of gamma correction can be secured at 8 bits or more, and deterioration of the bit precision can be prevented. For this reason, the gradation is improved as compared with the case where the input is 8 bits. In addition, since conversion is performed from 10 bits to 8 bits, signal processing after gamma processing becomes data processing of a general 8-bit configuration, and the cost of memory components and processing ICs is reduced.

  Here, the first gamma correction unit 86a has four gamma correction curves. The four characteristics of the four gamma correction curves are a normal observation mode, a high contrast mode (brighter is brighter and darker is darker), and a low contrast mode (brighter is darker and darker is brighter). ) And image processing mode (output with gamma = 1). The four gamma correction curves can be selected by an operator from a keyboard (not shown) according to the purpose of use of the operator.

  In the second preprocess 60b, the second output CCDOUT (B) from the CCD 10 is input from the channel B (hereinafter referred to as CHB). Since the second preprocess 60b has the same configuration as that of the first preprocess 60a, the same process as the process of the first preprocess 60a is performed on the CCDOUT (B).

  Next, based on FIG. 5, the synthesis of signals processed by the first preprocess 60a and the second preprocess 60b will be described.

  The same processing is performed in the first preprocess 60a and the second preprocess 60b, and the input signal (A) and the input signal (B) are input to the signal synthesis unit 62 from the first gamma correction unit 86a and the second gamma correction unit 86b. And synthesized.

  As described above, the signal processing unit 62 includes the first line memory 88a and the second line memory 88b. Also, the first line memory 88a and the second line memory 88b input signals at nHz (n is a coefficient) under the control of a timing control unit (not shown), and at a timing of 2nHz (twice the frequency of input), Read signals alternately. For this reason, one of the read data is delayed by a half cycle. In this way, the first line memory 88a and the second line memory 88b are alternately read out signals delayed by one half cycle, and the input signal (A) and the input signal (B) are synthesized by wired-off. . Reading and combining signals alternately as described above is the same as multiplexing and combining signals.

  The input signal (A) and the input signal (B) are combined by such an operation of the signal combining unit 62, and a combined output signal is obtained. Then, this combined output signal is input to the post process 64 at the subsequent stage.

  Returning to FIG. 4, the combined output signal shown in FIG. 5 output from the signal combining unit 62 is input to the post process 64. In the post process 64, first, the enhancement processing unit 90 performs enhancement processing on the combined output signal. This enhancement processing unit 90 changes the mask calculation coefficient of the spatial filter according to the number of pixels of the CCD of the connected electronic endoscope, the noise level, etc., changes the enhancement frequency of enhancement, ”Or“ Cut ”can be selected.

  The signal enhanced by the enhancement processing unit 90 is input to the subsequent digital signal processing unit 92. The post-stage digital signal processing unit 92 performs processing such as image enlargement processing, R, G, and B frame synchronization, color shift detection, and frame delay.

  The combined output signal output from the signal combining unit 62 is converted into an analog video signal by the D / A conversion unit 94 after a series of these processes.

(effect)
As described above, in the second embodiment, two-line reading CCD signal processing is performed by two systems of the same configuration, so that driving is performed at a lower frequency than when switching by one circuit. Can do. In addition, since the circuit has the same configuration, the circuit can be simplified and the circuit design is simplified. The foregoing also leads to cost reduction.

  Further, since the two systems of signals are combined digitally, there is less signal degradation than when analog signals are combined. Therefore, the frequency characteristics of the circuit can be improved and resolution degradation can be prevented.

  In the second embodiment, the first digital signal processing unit 84a, the second digital signal processing unit 84b, the first gamma correction unit 86a, and the second gamma correction unit 86b are provided before the signal synthesis unit 62. These may be arranged in the subsequent stage.

  Further, the first gamma correction unit 86a and the second gamma correction unit 86b perform conversion from 10 bits to 8 bits. However, even if the number of input bits is the same as the number of output bits, or the number of output bits is greater than the number of input bits. May be larger.

  Furthermore, in the second embodiment, the first gamma correction unit 86a and the second gamma correction unit 86b have four gamma correction curves. However, the four gamma correction curves are not fixed and are single or You can have more than one.

  The second embodiment is a two-line readout CCD that reads out even-numbered pixels and odd-numbered pixels in the horizontal direction using separate horizontal registers, but the even-numbered pixels in the vertical direction and odd-numbered pixels are odd-numbered. A two-line readout CCD that reads out the second pixel using a separate register may be used.

  Furthermore, in the second embodiment, a two-line readout CCD having two outputs is used, but a CCD having a plurality of outputs may be used.

[Appendix]
(Additional Item 1) An endoscope provided with a solid-state image sensor at the tip;
In an electronic endoscope apparatus comprising: a camera control unit having a signal processing unit that takes in an output signal of the solid-state imaging device and performs signal processing;
Drive signal generating means for generating a drive signal for driving the solid-state imaging device;
Connection detecting means for detecting the presence or absence of connection between the endoscope and the camera control unit;
An electronic endoscope apparatus comprising: drive signal control means for stopping output of the drive signal generation means based on a detection result of the connection detection means.

(Additional Item 2) In the camera control unit, a power supply circuit having a current limiting means is provided in the means for supplying power to the solid-state imaging device,
The electronic endoscope apparatus according to appendix 1, wherein the power supply circuit does not supply a certain amount of power.

  Conventionally, a method of detecting a failure state of the CCD and limiting a current value supplied to the CCD is known in order to prevent the CCD from generating heat in the event of a CCD failure. However, it is difficult to detect the failure state. There is a problem of circuit complexity.

  In the electronic endoscope apparatus according to appendix 2, the solid-state image pickup device provided at the distal end of the endoscope has failed due to a simple configuration in which a power supply circuit having a current limiting unit for the solid-state image pickup device is provided in the camera control unit. Even in this case, it is possible to always keep the calorific value below a certain level.

(Additional Item 3) In the camera control unit,
A patient circuit connecting the endoscope;
A secondary circuit electrically isolated from the patient circuit;
Synchronizing means for superimposing a synchronizing signal on the driving signal output from the driving generating means in the patient side circuit, and detecting the synchronizing signal superimposed in the patient side circuit in the secondary circuit The electronic endoscope apparatus according to Additional Item 1, further comprising detection means.

  Conventionally, for example, in Japanese Patent Application Laid-Open No. 64-72724, a solid-state imaging drive timing generator for driving a CCD is provided on the secondary circuit side, so the CCD is driven from the secondary circuit side to the patient side circuit side via an isolation element. A timing signal was sent. As a result, there are problems that the number of isolation elements increases and the transmission accuracy of the transmitted pulse timing becomes insufficient due to variations in the isolation elements.

  In the electronic endoscope device according to additional item 3, a patient-side circuit for connecting the endoscope to the camera control unit and a secondary circuit electrically insulated from the patient-side circuit are provided, and a synchronization signal is provided to the drive signal generating means. By superimposing the signal, the electrical signal from the solid-state imaging device to which the synchronization signal has been sent is sent to the secondary circuit side, and the synchronization signal is detected from the electrical signal on the secondary circuit side to synchronize the patient side circuit and the secondary circuit. As a result, when the electrical signal output from the solid-state imaging device passes through the isolation, it is possible to improve transmission accuracy without being affected by variations due to the characteristics of the isolation device.

(Additional Item 4) In the camera control unit,
A patient circuit connecting the endoscope;
Providing a secondary circuit electrically insulated from the patient side circuit;
Synchronization detection means for detecting the presence or absence of synchronization between the secondary circuit and the patient side circuit is superimposed in the secondary circuit, and a synchronization signal is superimposed on the drive signal output from the drive signal generation means in the patient side circuit. Each having superimposing means for
The electronic endoscope apparatus according to claim 1, wherein the superimposing unit superimposes a different signal on the driving signal based on a detection result of the synchronization detecting unit.

  In the conventional electronic endoscope apparatus, since the video signal is normally read from the beginning when the camera control unit is turned on, there is a problem that it is difficult to synchronize with the patient side circuit on the secondary circuit side.

  In the electronic endoscope apparatus according to additional item 4, in the synchronization detection unit in the secondary circuit, the superimposing unit superimposes a different signal on the drive signal based on the detection result of the synchronization detection unit. It is possible to perform synchronization detection.

(Additional Item 5) An endoscope provided with a solid-state imaging device having a plurality of outputs at the tip;
In an electronic endoscope apparatus comprising: a camera control unit having a signal processing unit that takes in an output of the solid-state imaging device and performs signal processing;
The signal processing means includes
A plurality of output signal processing means for signal processing a plurality of output signals from the solid-state imaging device;
An electronic endoscope apparatus comprising: signal combining means for digitally combining the plurality of output signals subjected to signal processing by a plurality of output signal processing means.

  In order to shorten the CCD image readout period, there is a two-line readout CCD that reads out even-numbered pixels and odd-numbered pixels in the horizontal direction using separate horizontal registers (hereinafter referred to as CH A and CH B). As a conventional technique, there is known an electronic endoscope apparatus that reads out by a horizontal transfer pulse having a phase difference of 180 degrees for each pixel using the two-line readout CCD. However, in the conventional electronic endoscope apparatus, the subsequent processing circuit must be composed of a high-speed analog circuit, and the signal from CH A and the signal from CH B must be synthesized in an analog manner. In order to drive at high speed, there is a problem that the frequency characteristic is deteriorated and the resolution is deteriorated.

  In the electronic endoscope apparatus according to additional item 5, the plurality of output signal processing units separately process signals from the plurality of outputs of the solid-state imaging device at the same timing, and a signal synthesis unit includes the plurality of output signal processing units. By digitally synthesizing the signals processed in step 1, it is possible to prevent resolution degradation without processing multiple output signals of the solid-state image sensor while switching the circuit at high speed and without having to synthesize in analog. And

(Additional Item 6) An endoscope provided with a solid-state imaging device having a plurality of outputs at the tip;
In an electronic endoscope apparatus comprising: a camera control unit having a signal processing unit that takes in an output of the solid-state imaging device and performs signal processing;
An electronic endoscope apparatus comprising drive signal generating means for generating horizontal transfer pulses at the same timing for driving the solid-state imaging device.

  In the electronic endoscope apparatus according to appendix 6, the drive signal generation unit generates horizontal transfer pulses at the same timing for driving the solid-state image sensor, thereby simultaneously receiving signals from a plurality of channels of the solid-state image sensor. It is possible to output.

(Additional Item 7) An endoscope provided with a solid-state image sensor at the tip;
In an electronic endoscope apparatus comprising: a camera control unit having a signal processing unit that takes in an output signal of the solid-state imaging device and performs signal processing;
The signal processing unit of the camera control unit includes a gamma correction unit in a digital processing unit that digitally processes an output signal of the solid-state imaging device,
The electronic endoscope apparatus characterized in that the number of input bits of the gamma correction means is larger than the number of output bits.

  In a conventional gamma correction unit that performs image correction, for example, the number of input and output bits is the same, and the slope of the gamma correction curve is not 1, so the apparent number of bits is reduced, the bit accuracy is degraded, and a sufficient level is obtained. There is a problem that the tonality cannot be maintained.

In the electronic endoscope apparatus according to appendix 7, the number of input bits of the gamma correction unit is made larger than the number of output bits, so that even if the slope of the gamma correction curve is larger than 1, deterioration of bit accuracy can be prevented. It is possible to maintain the gradation of the image.

1 is a block diagram showing a configuration of an electronic endoscope apparatus according to a first embodiment of the present invention. The block diagram which shows the structure of the patient side circuit of FIG. Timing chart for explaining the operation of the electronic endoscope apparatus of FIG. The block diagram which shows the structure of the principal part of the electronic endoscope apparatus which concerns on the 2nd Embodiment of this invention. Explanatory drawing explaining the effect | action of the signal synthetic | combination part of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electronic endoscope apparatus 2 ... Electronic endoscope 3 ... CCU
4 ... Light source device 5 ... TV monitor 10 ... CCD
DESCRIPTION OF SYMBOLS 12 ... Patient side circuit 14 ... Isolation element 16 ... Secondary circuit 18 ... Analog processing part 20 ... A / D conversion part 22 ... Digital processing part 24 ... D / A conversion part 30 ... CCD driver 32 ... FPGA
34 ... Data ROM
36 ... CCD detection circuit 38 ... cable matching circuit 40 ... cable matching switching circuit 42 ... preamplifier unit 44 ... CCD power supply circuit 46 ... main power supply 50 ... horizontal transfer drive pulse generation circuit 52 ... vertical transfer drive pulse generation circuit 54 ... anti-blooming Pulse generation circuit
Attorney Susumu Ito

Claims (3)

An endoscope provided with a solid-state imaging device capable of outputting a plurality of imaging signals at the tip;
A camera control unit having signal processing means for receiving an imaging signal from the solid-state imaging device and performing predetermined signal processing on the imaging signal;
In an electronic endoscope apparatus comprising:
The signal processing means includes
A plurality of analog signal processing means for respectively receiving a plurality of imaging signals from the solid-state imaging device and applying predetermined analog signal processing to the respective imaging signals;
A plurality of A / D conversion means for A / D converting each of the plurality of analog processing signals subjected to the analog signal processing in the plurality of analog signal processing means;
Digital signal synthesizing means for performing a predetermined synthesizing process on the plurality of digital signals respectively A / D converted by the plurality of A / D conversion means;
With
An electronic endoscope apparatus characterized in that the processing speed after synthesis is faster than the processing speed before synthesis before and after the synthesis processing in the digital signal synthesis means. An endoscope provided at the tip with a solid-state imaging device capable of outputting a plurality of imaging signals that can be read simultaneously;
A camera control unit having storage means capable of storing a predetermined video signal, and signal processing means for receiving an imaging signal of the solid-state imaging device and performing predetermined signal processing on the imaging signal;
In an electronic endoscope apparatus comprising:
The signal processing means includes
First signal processing means for receiving each image signal simultaneously read from the solid-state image sensor, performing a predetermined process on each image signal, and writing to a predetermined storage means;
Second signal processing means for reading a predetermined video signal from the storage means;
Imaging function control means for controlling an imaging function based on a signal from the first signal processing means;
An electronic endoscope apparatus comprising:   The electronic endoscope apparatus according to claim 2, wherein the imaging function control unit controls a γ correction function and a white balance function.

Images