JP2004121856A - Endoscope apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic endoscope apparatus to simplify the processing. <P>SOLUTION: The electronic endoscope apparatus includes an endoscope which has a solid-state image sensing element with several outputs and prepared at the leading edge, and a camera control unit which has a signal processing means to receive the outputs from the solid-state image sensing element and to perform the signal processing, wherein a drive signal generating means is provided to generate a horizontal forwarding pulse of the same timing for actuating the solid-state image sensing element. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to an electronic endoscope apparatus, and more particularly, to an electronic endoscope apparatus having a feature in a control portion of a drive signal of a solid-state imaging device.

In recent years, an insertion portion is inserted into a body cavity, and illumination light is applied to an observation site at the distal end of the insertion portion by an illumination light transmission unit such as a light guide fiber bundle, so that an image of the observation site is obtained, and the observation site is observed and treated. Endoscope devices are widely used.

In one of the endoscope apparatuses, a solid-state imaging device, for example, a CCD is provided at the tip of an insertion portion, an image of an observation site is formed on an imaging surface by an objective optical system, and converted into an electric signal. There is an electronic endoscope apparatus which can display an image of an observation site on a monitor or the like by processing a signal of the electronic part, and store the image data in an information recording device or the like.

In such an electronic endoscope apparatus, in order to shorten the image reading period of the CCD, even-numbered pixels and odd-numbered pixels in the horizontal direction are separately set using horizontal registers (hereinafter, CH A, CH B). A device using a two-line read CCD for reading is known.

However, since reading is performed with horizontal transfer pulses having a phase difference of 180 degrees for each pixel, two circuits for generating horizontal transfer pulses are required, and the processing is complicated and the circuit scale becomes large. Further, when the signal processing of the two-line readout CCD is performed while being switched by one circuit, the processing becomes complicated.

Furthermore, even in the two circuits, the processing circuit in the subsequent stage is constituted by a high-speed analog circuit, so that the signal from CH A and the signal from CH B must be combined in an analog manner, and the analog circuit is driven at high speed. Therefore, there is a problem that the frequency characteristics are deteriorated, the resolution is deteriorated, and the processing is complicated.

The present invention has been made in view of the above circumstances, and has as its object to provide an electronic endoscope apparatus that can simplify the processing.

A first electronic endoscope apparatus according to the present invention is a camera control having an endoscope provided with a solid-state imaging device having a plurality of outputs at a tip thereof, and signal processing means for taking in an output of the solid-state imaging device and performing signal processing. An electronic endoscope apparatus comprising a unit and a drive signal generating means for generating horizontal transfer pulses at the same timing for driving the solid-state imaging device.

Further, a second electronic endoscope apparatus according to the present invention includes an endoscope provided with a solid-state imaging device having a plurality of outputs at a tip thereof, and a signal processing unit which takes in an output of the solid-state imaging device and performs signal processing. In an electronic endoscope apparatus including a camera control unit, the signal processing unit includes a plurality of output signal processing units that perform signal processing on a plurality of output signals from the solid-state imaging device, and the plurality of output signal processing units. Signal synthesizing means for digitally synthesizing the plurality of output signals subjected to signal processing.

Furthermore, a third electronic endoscope apparatus of the present invention includes an endoscope provided with a solid-state imaging device having a plurality of outputs at a tip thereof, and a signal processing unit that takes in an output of the solid-state imaging device and performs signal processing. In an electronic endoscope apparatus including a camera control unit, a driving signal generating unit that generates horizontal transfer pulses at the same timing for driving the solid-state imaging device, and the driving signal generating unit simultaneously outputs the solid-state imaging device from the solid-state imaging device. A plurality of output signal processing means for performing signal processing on the plurality of output signals outputted; and a signal combining means for digitally combining the plurality of output signals subjected to signal processing by the plurality of output signal processing means. Features.

According to the present invention, the drive signal generation unit generates horizontal transfer pulses at the same timing for driving the solid-state imaging device, so that signals of the same phase can be output from a plurality of channels of the solid-state imaging device. Processing can be simplified.

In addition, since a plurality of output signals from the solid-state imaging device are processed by a plurality of output signal processing means having the same configuration, the processing is simplified and the operation at a low frequency is simplified as compared with the case where switching is performed by a single circuit. Driving becomes possible.

Furthermore, since a plurality of output signals processed by the plurality of output signal processing means are digitally combined, the processing is simplified, the frequency characteristics are improved, and the deterioration of resolution is reduced as compared with the case of combining analog signals. Can be prevented.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 to 4 relate to a first embodiment of the present invention, FIG. 1 is a block diagram showing a configuration of an electronic endoscope apparatus, and FIG. 2 is a block diagram showing a configuration of a patient side circuit of FIG. 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 for observing the inside of a body cavity, and a camera control unit (a camera control unit for processing signals from the electronic endoscope 2). The light source device 4 supplies illumination light for illuminating 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 also outputs 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. And a secondary circuit 16 (signal processing means) for 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 converter that converts an analog signal output from the analog processing unit 18 into a digital signal. A digital processing unit 22 for processing a digital signal from the A / D conversion unit 20; and a D / A conversion unit 24 for converting a digital signal output from the digital processing unit 22 into an analog signal. I have.

In the electronic endoscope 2, the CCD 10 is driven by a patient side circuit 12, 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 a subject image formed on the CCD 10 by a lens unit (not shown) into an electric signal and outputs the electric signal 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.

(4) In the secondary circuit 16, the analog processing unit 18 performs processes such as control of a synchronization signal 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 the digital signal 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 on the TV monitor 5 as a video.

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

As shown in FIG. 2, the patient side circuit 12 includes a CCD driver 30 (drive signal generating means) for driving the CCD 10, a CCD drive timing signal for outputting the CCD drive timing signal to the CCD driver 30, and a programmable and driveable 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 synchronizing signal described later, a data ROM 34 for programming the FPGA 32, and detection of the type of CCD and connection state A CCD detecting circuit 36 (connection detecting means), a cable matching circuit 38 for correcting the matching of a cable for transmitting a CCD drive signal to the CCD 10, and a cable matching circuit 38 adapted to the CCD 10 based on a selection signal output from the FPGA 14. Choose a cable match A switching circuit 40, a preamplifier unit 42 for amplifying an electric signal read from the CCD 10, a CCD power supply circuit 44 for limiting the power supply to the CCD 10, and supplying power to the CCD power supply circuit 44. And a main power supply 46.

{Circle around (4)} The CCD driver 30 includes a horizontal transfer drive pulse generation circuit 50 and a vertical transfer drive pulse generation circuit 52 for transferring electric charges accumulated in the CCD 10, and an anti-blooming pulse generation circuit 54 for suppressing blooming.

(Action)
Next, the operation of the thus-configured electronic endoscope apparatus 1 of the present embodiment will be described.

First, a method of detecting 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, φA is an enlarged view of the timing chart of 1L of the CCD horizontal transfer pulse during the video signal reading period, and TA is an enlarged view of the CCD output at this time. The enlarged view of the timing chart of 1L of the CCD horizontal transfer pulse at the end of 1V and the enlarged view of the CCD output at that time are shown by φB and TB, respectively, in the same manner as described above. The above 1V indicates one field period (1/60 s), and 1L indicates about 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. By doing so, a CCD output having a phase shifted by 180 degrees from the CCD output in the other 1L period is generated.

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

Here, if the phase of the CCD output is shifted by 180 degrees, the polarity of the output is inverted during the period in which the phase of the CDS output is shifted by 180 degrees as shown by the CDS output in FIG. In this manner, the synchronizing signal is superimposed on the electric signal read from the CCD 10 only during the 1 L period at the end of 1 V. Then, the patient circuit 12 and the secondary circuit 16 are synchronized by resetting the FPGA 32 with the detected synchronization VRST.

Although not shown, the analog processing unit 18 includes a PLL unit that compares the phases of signals output from the patient-side circuit 12 and a synchronization detection unit that detects whether or not the secondary circuit 16 is synchronized with the patient-side circuit 12. Means for controlling the FPGA 32 based on the detection result of the synchronization detecting means, so that when the synchronization is not achieved, a signal which allows the secondary circuit 16 to perform phase comparison for the entire period so that synchronization can be easily performed. Is superimposed on the CCD drive signal. When synchronization is achieved, a signal that can be compared in phase for a certain period is superimposed on the CCD drive signal.

In the electronic endoscope apparatus 1 according to the present embodiment, when the power is turned on, 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. The data ROM 34 programs the programmable FPGA 32 based on the detection result of the CCD detection circuit 36.

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, S2, vertical transfer drive timing signal S3, and anti-blooming timing signal S4.

(4) The CCD drive timing signal is voltage-amplified by the horizontal transfer drive pulse generation circuit 50, the vertical transfer drive generation circuit 52, and the anti-blooming pulse generation circuit 54, respectively.

On the other hand, the cable matching switching circuit 40 selects a cable matching circuit 38 adapted to the CCD 10 based on a selection signal for selecting the CCD 10 output from the FPGA 32, shapes the waveform by the cable matching circuit 38, and drives each of the CCDs 10. , A CCD horizontal transfer drive pulse, a CCD vertical transfer drive pulse, and an anti-blooming pulse.

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 drive 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 according to the type of the 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 drive current of 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 detects the detection result of the CCD detection circuit 36. By stopping the CCD vertical transfer drive timing signal S3 which is the output, the CCD vertical transfer drive pulse for driving the CCD 10 is stopped. Therefore, when the electronic endoscope 2 is connected to the patient side circuit 12 again, Prior to the power supply to the CCD 10, the CCD drive signal is not supplied to the CCD 10, so that the 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 the timings are the same, the patient The preamplifier unit 42, the isolation element 14, the analog processing unit 18, the A / D conversion unit 20, and a part of the digital processing unit 22 in the side circuit 12 constitute two systems. When the number of CCD horizontal transfer drive pulses is two or more, the number of the same circuits becomes two or more. The same applies to this case.

(4) When the electronic endoscope 2 is not connected, the CCU 3 may partially stop the output of the FPGA 32 and stop only a part of the CCD drive pulse. Further, the CCD driving pulse may be stopped by stopping the CCD driver 30. Further, all outputs of the power supply supplied to the CCD 10 may be stopped.

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

Further, for the CCD 10 that does not require the anti-blooming pulse, the anti-blooming pulse for driving the CCD 10 may be stopped by the FPGA 32 stopping the anti-blooming timing signal S4 according to the CCD detection circuit 36. Here, the cable matching circuit 38 may be the same circuit for different CCDs 10 when the cable length is a fixed length.

When the 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 which are easy to synchronize. May be avoided.

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

The anti-blooming pulse has a clocking AC component period and a DC component period of only a DC component. Here, the anti-blooming pulse generation circuit 54 adjusts the AC period and the DC component period separately depending on the type of CCD. Reductions may be made.

The preamplifier unit 42 is configured by a differential amplifier circuit, but may be configured by a single-stage amplifier circuit.

4 and 5 relate to a second embodiment of the present invention. FIG. 4 is a block diagram showing a configuration of a main part of the electronic endoscope apparatus, and FIG. 5 explains an operation of the signal synthesizing section of FIG. FIG.

る の で Since the second embodiment is almost the same as the first embodiment, only different points will be described, and the same components will be 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. The CCD is driven by pulses of the same timing output from a CCD horizontal transfer drive pulse generation circuit to process signals from the CCD. This means is performed by two circuits having the same configuration, and the signals processed by the two circuits 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 block. A first preprocess 60a and a second preprocess 60b, a signal synthesizing unit 62 for synthesizing the digital signals from the two first and second preprocesses 60a and 60b, and a post for processing the signal synthesized by the signal synthesizing unit 62 And a 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, and A first differential amplifier 74a for removing and amplifying signal noise, 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 that converts an output of the first analog signal processing unit 80a into a digital signal, and a conversion by the first A / D conversion unit 82a A first digital signal processing unit 84a that performs various digital signal processing on the processed digital signal, and a digital signal processed by the first digital signal processing unit 84a. And a first gamma correction unit 86a that performs gamma correction Le signal.

The second preprocess 60b has the same configuration as the first preprocess 60a, and includes a second preamplifier 70b for amplifying the other signal from the CCD 10 (not shown), the patient side circuit 12, and the secondary circuit. 16, a second differential amplifier 74b for removing and amplifying a signal noise, a second CDS circuit 76b for performing correlated double sampling, a patient side circuit 12, and a secondary circuit. 16, a second PLL circuit 78b for synchronizing, a second analog signal processing unit 80b for performing various analog signal processing, and a second A / D converter for converting an output of the second analog signal processing unit 80b into a digital signal. 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.

出力 The outputs from the first preprocess 60a and the second preprocess 60b are input to the signal synthesis unit 62. Then, as shown in FIG. 5, the signal synthesis 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 comprises a one line memory 88a and a second line memory 88b.

The signal synthesizing unit 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 a mask operation to enhance the band of the spatial frequency, enhances the spatial frequency, a post-stage digital signal processor 92 that processes various digital signals via the enhancer 90, and an output of the post-stage digital signal processor 92. Is converted to an analog signal.

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

(Action)
Here, the respective components of the first preprocess 60a and the second preprocess 60b all 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, 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 is correlated double-sampled. Here, the patient circuit 12 and the secondary circuit 16 are synchronized with the CCD output signal by the first PLL circuit 78a. The signal that has been correlated double-sampled 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 in 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 clamp processing and white balance in a 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 an image. 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 to 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. Further, since the signal is converted from 10 bits to 8 bits, the signal processing after the gamma processing becomes a general 8-bit data processing, and the cost of the memory components and the processing IC is reduced.

Here, the first gamma correction unit 86a has four gamma correction curves. The four characteristics based on the four gamma correction curves are a normal observation mode, a high contrast mode (brighter places are brighter, dark places are darker), and a low contrast mode (bright places are darker and dark places are 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 pre-process 60b, the second output CCDOUT (B) from the CCD 10 is input from the channel B (hereinafter, CHB). Since the second preprocess 60b has the same configuration as the first preprocess 60a, the second preprocess 60b performs exactly the same process as that of the first preprocess 60a on CCDOUT (B).

Next, the synthesis of the signals processed in the first preprocess 60a and the second preprocess 60b will be described with reference to FIG.

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 combining unit 62 from the first gamma correction unit 86a and the second gamma correction unit 86b. And synthesized.

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

(4) The input signal (A) and the input signal (B) are combined by the operation of the signal combining unit 62 to obtain a combined output signal. Then, the synthesized 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. Then, in the post-process 64, first, the enhancement processing section 90 performs enhancement processing on the synthesized output signal. The enhancement processing unit 90 changes the mask operation coefficient of the spatial filter according to the number of pixels of the CCD of the electronic endoscope to be connected, the noise level, and the like, and changes the enhancement emphasis frequency, or “emphasis”. "And" cut "can be selected.

The signal that has been subjected to the enhancement processing 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, synchronization of R, G, and B frames, color shift detection, and frame delay.

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

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

Furthermore, since the synthesis of the two systems of signals is performed digitally, signal degradation is less than in the case where analog signals are synthesized. Therefore, the frequency characteristics of the circuit are improved, and the deterioration of the resolution can be prevented.

In the second embodiment, the first digital signal processing unit 84a and 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. , May be arranged at a later stage.

Although the first gamma correction unit 86a and the second gamma correction unit 86b convert from 10 bits to 8 bits, the number of input bits and the number of output bits may be the same, or the number of output bits may be smaller than the number of input bits. May be larger.

Further, in the second embodiment, the first gamma correction unit 86a and the second gamma correction unit 86b are assumed to have four gamma correction curves. You can have more than one.

Further, the second embodiment is a two-line read CCD in which even-numbered pixels and odd-numbered pixels in the horizontal direction are read using separate horizontal registers. However, even-numbered pixels in the vertical direction and odd-numbered pixels are read out. It is also possible to use a two-line readout CCD for reading out the pixel using a separate register.

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

[Appendix]
(Additional Item 1) An endoscope provided with a solid-state imaging device at its tip,
A camera control unit having a signal processing unit that captures an output signal of the solid-state imaging device and performs signal processing.
Drive signal generation means for generating a drive signal for driving the solid-state imaging device,
Connection detection means for detecting the presence or absence of connection between the endoscope and the camera control unit,
A drive signal control unit for stopping the output of the drive signal generation unit based on a detection result of the connection detection unit.

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

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

In the electronic endoscope apparatus according to Additional Item 2, the solid-state imaging device provided at the distal end of the endoscope fails due to a simple configuration in which a power supply circuit having current limiting means for the solid-state imaging device is provided in the camera control unit. In this case, the calorific value can always be kept below a certain value.

(Appendix 3) In the camera control unit,
A patient-side circuit connecting the endoscope,
Providing a secondary circuit electrically isolated from the patient circuit;
Superimposing means for superimposing a synchronizing signal on the driving signal output by the driving generating means in the patient-side circuit; synchronizing detecting the synchronizing signal superimposed in the patient-side circuit in the secondary circuit; 2. The electronic endoscope apparatus according to claim 1, further comprising a detection unit.

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. Therefore, the CCD drive is performed from the secondary circuit side to the patient side circuit via an isolation element. A timing signal was being sent. As a result, there is a problem that the number of isolation elements increases and the transmission accuracy of the transmitted pulse timing becomes insufficient due to the variation of the isolation elements.

The electronic endoscope apparatus according to claim 3, further comprising a patient circuit for connecting the endoscope to the camera control unit, and a secondary circuit electrically insulated from the patient circuit. , The electric signal from the solid-state imaging device to which the synchronizing signal has been sent is sent to the secondary circuit side, and the synchronizing signal is detected from the electric signal on the secondary circuit side to synchronize the patient side circuit and the secondary circuit. Thus, when the electric signal output from the solid-state imaging device passes through the isolation, the transmission accuracy can be improved without being affected by the variation due to the characteristics of the isolation device.

(Appendix 4) In the camera control unit,
A patient-side 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 circuit in the secondary circuit, and a synchronization signal superimposed on the drive signal output by the drive signal generation means in the patient circuit. Respectively comprising superimposing means for causing
The electronic endoscope apparatus according to claim 1, wherein the superimposing unit superimposes a different signal on the drive signal based on a detection result of the synchronization detecting unit.

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

In the electronic endoscope apparatus according to Appendix 4, the superimposing means superimposes a different signal on the drive signal based on a detection result of the synchronization detecting means, so that the synchronization detecting means in the secondary circuit can easily perform the operation. To perform synchronization detection.

(Additional Item 5) An endoscope provided with a solid-state imaging device having a plurality of outputs at a tip thereof,
A camera control unit having signal processing means for taking in the output of the solid-state imaging device and performing signal processing.
The signal processing means,
A plurality of output signal processing means for performing signal processing on a plurality of output signals from the solid-state imaging device,
An electronic endoscope apparatus comprising: a signal synthesizing unit that digitally synthesizes the plurality of output signals processed by the plurality of output signal processing units.

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

In the electronic endoscope apparatus according to Supplementary Note 5, the plurality of output signal processing units separately process signals from a plurality of outputs of the solid-state imaging device at the same timing, and the signal combining unit includes the plurality of output signal processing units. Digitally synthesizes the signals processed by, without switching multiple circuits, and without processing multiple output signals of the solid-state image sensor, and without the need to synthesize in analog form, it is possible to prevent resolution degradation. And

(Additional Item 6) An endoscope provided with a solid-state imaging device having a plurality of outputs at a tip thereof;
A camera control unit having signal processing means for taking in the output of the solid-state imaging device and performing signal processing.
An electronic endoscope apparatus, further 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 generating means generates horizontal transfer pulses at the same timing for driving the solid-state imaging device, thereby simultaneously transmitting signals from a plurality of channels of the solid-state imaging device. It is possible to output.

(Additional Item 7) An endoscope provided with a solid-state imaging device at its tip,
A camera control unit having a signal processing unit that captures 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 number of input bits of the gamma correction means is larger than the number of output bits.

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

In the electronic endoscope device according to additional item 7, by making the number of input bits of the gamma correction means larger than the number of output bits, even if the slope of the gamma correction curve is larger than 1, deterioration of bit accuracy can be prevented. Can be maintained.

FIG. 1 is a block diagram illustrating a configuration of an electronic endoscope apparatus according to a first embodiment of the present invention. FIG. 2 is a block diagram showing the configuration of the patient-side circuit of FIG. A timing chart for explaining the operation of the electronic endoscope apparatus of FIG. FIG. 4 is a block diagram showing a configuration of a main part of an electronic endoscope apparatus according to a second embodiment of the present invention. Explanatory drawing explaining the effect | action of the signal synthesis part of FIG.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 ... Electronic endoscope apparatus 2 ... Electronic endoscope 3 ... CCU
4: Light source device 5: TV monitor 10: CCD
12 patient circuit 14 isolation element 16 secondary circuit 18 analog processing unit 20 A / D conversion unit 22 digital processing unit 24 D / A conversion unit 30 CCD driver 32 FPGA
34 ... Data ROM
36 CCD detection circuit 38 Cable matching circuit 40 Cable matching switching circuit 42 Preamplifier 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 Generator Circuit Attorney Susumu Ito

Claims (3)

An endoscope provided with a solid-state imaging device having a plurality of outputs at a tip thereof, and an electronic endoscope device including a camera control unit having a signal processing unit that captures an output of the solid-state imaging device and performs signal processing.
An electronic endoscope apparatus comprising a drive signal generating means for generating horizontal transfer pulses at the same timing for driving the solid-state imaging device. An endoscope provided with a solid-state imaging device having a plurality of outputs at its tip, and an electronic endoscope device including a camera control unit having a signal processing unit that captures an output of the solid-state imaging device and performs signal processing.
The signal processing means,
A plurality of output signal processing means for performing signal processing on a plurality of output signals from the solid-state imaging device,
Signal synthesizing means for digitally synthesizing the plurality of output signals signal-processed by the plurality of output signal processing means,
An electronic endoscope apparatus comprising: An endoscope provided with a solid-state imaging device having a plurality of outputs at a tip thereof, and an electronic endoscope device including a camera control unit having a signal processing unit that captures an output of the solid-state imaging device and performs signal processing.
Drive signal generation means for generating a horizontal transfer pulse at the same timing for driving the solid-state imaging device,
A plurality of output signal processing means for performing signal processing on a plurality of output signals simultaneously output from the solid-state imaging device by the drive signal generation means,
Signal synthesizing means for digitally synthesizing the plurality of output signals signal-processed by the plurality of output signal processing means,
An electronic endoscope apparatus comprising:

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