JPH09154813A - Electronic endoscope device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic endoscope device capable of minimizing the scale of a high-frequency circuit in a patient circuit for maintaining an automatic lighting control function, and ensuring high EMC. SOLUTION: A signal outputted from the image pickup element 10 of an electronic endoscope 2, due to a drive signal outputted from a driver 42 in the patient circuit of a video processor 4A, passes a differential amplifier 43 and inputted at the CDS circuit 45 of a secondary circuit via an isolation transformer 44. In the patient circuit, an output signal from the differential amplifier 43 is sent to a clamp circuit 52, and clamped with clamp pulses during the period when reset pulses are interrupted during a blanking period other than an imaging period. Thereafter, the black level of the signal is regenerated with DC and further detected with a lighting control signal generation circuit 53, thereby generating an EE signal 54 for lighting control. At the same time, the open and close amount of a diaphragm 7 is controlled via a diaphragm control circuit 21 in a light source device 3, and the quantity of illumination light is thereby automatically controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic endoscope apparatus equipped with automatic light control means for automatically controlling the amount of light for medical examination.

[0002]

2. Description of the Related Art Conventionally, an automatic light control mechanism in an electronic endoscope device controls a diaphragm of a light source device by using a light control signal obtained by averaging a video signal obtained based on reflected light from a subject. The light intensity is adjusted. FIG. 20 shows an electronic endoscope apparatus 1C having a general configuration for producing a dimming signal (hereinafter referred to as an EE signal) obtained by averaging this video signal.

The electronic endoscope apparatus 1C performs signal processing for the electronic endoscope 2 having a built-in image pickup means, a light source device 3 for supplying illumination light to a light guide of the electronic endoscope 2, and an image pickup means. Video processor 4C and monitor 5 for displaying a video signal output from the video processor 4C
It is composed of

Illumination light of the lamp 6 in the light source device 3 has a diaphragm 7
Is supplied to the rear end of the light guide 8 of the electronic endoscope 2, is transmitted to the distal end side of the insertion portion by the light guide 8, and the examination light is emitted forward from the distal end surface of the light guide 7,
A site to be inspected such as a diseased part in the body cavity is illuminated with the examination light. The illuminated inspection site is subjected to photoelectric conversion by forming an optical image of the optical image on an image pickup device 10 as an image pickup means by an objective lens 9 arranged at the tip of the insertion portion.

A drive signal is applied from the driver 11 in the video processor 4C to the image pickup device 10 to read out the photoelectrically converted signal, which is input to the preamplifier 12 and amplified, and then the correlated double sampling circuit. (Hereinafter, abbreviated as CDS circuit) 13 and a phase locked loop circuit (abbreviated as PLL circuit) 14 are input.

A clock that is phase-synchronized with the output signal of the image pickup device 10 is generated by the PLL circuit 14, and this clock is input to the pulse generation circuit 15, and a sampling pulse 16 that is synchronized with this clock is generated. The sampling pulse 16 is applied to the CDS circuit 13 to remove the reset pulse portion or the reset signal portion (hereinafter, φR portion) from the output signal of the preamplifier 12 and then input to the modulation circuit 17 and the clamp circuit 18.

The clamp circuit 18 clamps the black level of the signal that has passed through the CDS circuit 13 to extract a signal component whose black level is 0 level, and the dimming signal creating circuit 19
Is input to The dimming signal creating circuit 19 integrates the inputted signal to control the light quantity, and the dimming signal (EE
Signal), and the aperture control circuit 2 in the light source device 3
Apply to 1.

The diaphragm control circuit 21 generates a signal for controlling the opening and closing of the diaphragm 7 according to the input EE signal so that the amount of illumination light supplied to the light guide 8 via the diaphragm 7 is proportional to the EE signal. Automatic dimming is performed.

Since the output signal of the CDS circuit 13 is a baseband signal, it is modulated as an AC signal by the modulation circuit 17 and is used as an isolation means for isolating the leakage current between the patient circuit and the secondary circuit. It is input to the primary winding of the ration transformer 22 and induces a signal in the secondary circuit of the secondary winding. Since the electronic endoscope 2 is inserted into the body cavity, the power source of the patient circuit such as the driver 11 and the preamplifier 12 connected to the image pickup device 10 in the electronic endoscope 2 is insulated from the power source of the secondary circuit. , Ensuring safety.

The signal of the secondary winding of the isolation transformer 22 is input to the demodulation circuit 23 and demodulated to generate a baseband signal. This signal is supplied to the video processing circuit 2.
4 is input to the monitor 4, converted into a standard video signal, then output to the monitor 5, and an image of the inspection target portion is displayed on the display surface of the monitor 5.

The EE signal generated by the video processor 4C is transmitted to the diaphragm control circuit 21 of the light source device 3 through the transmission line 25 in the electronic endoscope 2 as shown in FIG. 21, or as shown in FIG. The light source device 3 is provided with the transmission cable 26 and the connector 27, the connector 27 is connected to the rear panel of the video processor 4C, and then the EE signal is transmitted to the aperture control circuit 21 of the light source device 3 to control the light amount. .

In order to generate the EE signal, it is necessary to clamp the reference black level because the amount of level fluctuation of the image portion of the output signal of the image pickup device 10 is extracted and created. However, it is difficult to clamp the black level in the output signal of the image pickup device 10 because the φR portion exists on the side opposite to the video signal portion or the video portion as shown in FIG. Therefore, after the CDS circuit 13 performs the CDS to cancel the φR portion, the clamp circuit 18 clamps the black level.

However, when the CDS circuit 13 is provided in the patient circuit, the following circuit is required in the patient circuit, and the size of the patient circuit is large. That is, the sampling pulse 16 synchronized with the output signal of the image sensor 10 is required to perform the CDS, and the PLL circuit 14 is required to realize this synchronization.

Since the signal after the CDS is processed in the secondary circuit, it must be insulated from the patient circuit and transmitted to the secondary circuit. As a method thereof, JP-A-63-2
As disclosed in Japanese Patent Publication No. 09626, the above-mentioned CDS
The signal after performing the above is band-converted to realize the insulated transmission through the isolation transformer 22, but for that purpose, the modulation circuit 17 and the demodulation circuit 23 are required.

As described above, as the scale of the patient circuit increases, the levels of leakage current, EMC, etc. may deteriorate, and it is necessary to separately take measures against these.

Next, in order to reduce the scale of the patient circuit,
FIG. 23 shows a general configuration when the CDS circuit 13 is provided on the secondary circuit side. The electronic endoscope apparatus 1D shown in FIG. 23 differs from that of FIG. 21 only in the internal configuration of the video processor 4D.

In the electronic endoscope apparatus 1D shown in FIG. 23, the output signal of the image pickup device 10 is directly input to the isolation transformer 22 via the preamplifier 12, and is transmitted from the patient circuit side to the secondary circuit side through the isolation transformer 22. This is disclosed in Japanese Patent Laid-Open No. 64-72724. The signal transmitted to this secondary circuit is the CDS circuit 1
3 and after the φR portion is removed, the video processing circuit 2
4 and the clamp circuit 18 are input.

The signal input to the dimming signal generating circuit 19 is integrated to generate the EE signal 30, and the EE signal 3 is generated.
0 is input to the modulation circuit 31, modulated, and then input to the demodulation circuit 33 on the patient circuit side through the photocoupler 32. The EE signal is demodulated by the demodulation circuit 33, and the EE signal is input to the diaphragm control circuit 21 to control the opening / closing amount of the diaphragm 7 to perform automatic light control.

Since the EE signal 30 generated by the dimming signal generating circuit 19 in this manner is a direct current signal in the secondary circuit, the modulation circuit 31 band-converts it into a pulse signal,
It is necessary to insulate and transmit to the patient circuit side through the photocoupler 32. Then, the pulse signal transmitted to the patient circuit side is converted into a DC signal by the demodulation circuit 33, and the EE signal 34 as the patient circuit is created.

[0020]

However, the EE signal 30 is modulated and demodulated in this way to obtain the EE signal 34.
When the signal is generated, a transmission delay or an error in the photometric level occurs, the response of the automatic light control is deteriorated, and the level of the EE signal 34 varies due to the offset of the modulation circuit and the demodulation circuit interposed in the middle. there is a possibility.

The present invention has been made in view of the above-mentioned points, and solves the above-mentioned problems, keeps the function of automatic dimming by minimizing the scale of the high frequency circuit in the patient circuit, and E
It is an object of the present invention to provide an excellent electronic endoscope device on the MC.

[0022]

[Means for Solving the Problems] Illuminating means for irradiating a body cavity with examination light, imaging means for converting an optical image of a subject illuminated by the examination light into an electric signal, and insulating leakage current. Isolation means for transmitting the output signal of the imaging means, correlation double sampling means for correlative double sampling the output signal of the imaging means transmitted by the isolation means, and output of the correlation double sampling means A signal processing means for processing a signal to generate a video signal that can be input to a display device; and an electronic endoscope apparatus comprising: an output signal of the image pickup means before transmission by the isolation means; By providing the dimming signal generating means for generating the control signal used for automatic dimming, the patient circuit on the upstream side of the isolation means can be constructed with a small circuit scale. It realizes the function of the dynamic dimming, so that can also simplify EMC measures.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) FIGS. 1 and 2 relate to a first embodiment of the present invention, and FIG. 1 shows the overall configuration of an electronic endoscope apparatus according to the first embodiment of the present invention. FIG. 2 shows an explanatory diagram of the operation of the first embodiment.

The electronic endoscope apparatus 1A according to the first embodiment of the present invention shown in FIG. 1 is an electronic endoscope 2 having a built-in image pickup means.
A light source device 3 for supplying illumination light to the light guide of the electronic endoscope 2, a video processor 4A for performing signal processing on the image pickup means and generating a video signal that can be input to the display device, and the video processor 4A. And a monitor 5 as a display device for displaying a video signal output from the. This electronic endoscope apparatus 1A is different from the electronic endoscope apparatus 1D of FIG. 25 only in the configuration of the video processor 4A,
Since the other components have the same configuration, they are denoted by the same reference symbols except for the video processor 4A.

A drive pulse generating circuit 41 is provided as a patient circuit of the video processor 4A, and drive signals φH1 and φH output from the drive pulse generating circuit 41 are provided.
2, φR and the like are applied to the image pickup device 10 via the driver 42, and the image pickup device 10 is driven by these drive signals to output a photoelectrically converted signal.

The output signal of the image pickup device 10 is amplified by the differential preamplifier 43, and then the leakage current between the patient circuit and the secondary circuit is insulated, or only the signal transmission is performed with the power supplies of both circuits insulated. It is transmitted from the patient circuit to the secondary circuit side through the isolation transformer 44 as the isolation means. The output signal of the image pickup device 10 is normally shown in FIG.
As shown in FIG. 4, since it is an alternating current (high frequency signal) in which a φR portion having a polarity opposite to that of the image portion side is present, it can be transmitted from the patient circuit to the secondary circuit side via the isolation transformer 44.

The signal transmitted to the secondary circuit side through the isolation transformer 44 is input to the CDS circuit 45 and the PLL circuit 46. The PLL circuit generates a clock phase-synchronized with the φR section, and outputs this pulse to the pulse generation circuit 4
7, the pulse generator circuit 47 generates a sampling pulse 48 synchronized with this clock, and the CDS circuit 4
5 is applied.

In the CDS circuit 45, the video portion is sampled by this sampling pulse, the φR portion is removed from the input signal to extract the baseband signal component,
It is input to the video processing circuit 49. In the video processing circuit 49, a standard video signal, that is, a video signal in a standard television format is generated and input to the monitor 5, and an image of the inspection target part is displayed.

In the present embodiment, a control signal for automatically adjusting the light quantity of the illumination means is generated before the output of the image pickup means is transmitted to the secondary circuit by the isolation means, that is, in the patient circuit. That is, the output of the differential preamplifier 43 is input to the clamp circuit 52, and the black level is clamped by clamping with the clamp pulse during the period in which the φR portion is stopped in the blanking period other than the video period, thereby extracting the video portion. Then, the dimming signal generating circuit 53 performs detection or the like to generate an EE signal. The configuration will be described more specifically below.

As described above, the output signal of the image pickup device 10 usually has the φR portion on the opposite side to the image portion side, as shown in FIG. 24, so that it is difficult to clamp the black level as it is. is there.

Therefore, in this embodiment, a reset pulse drive control circuit 50 is provided, and the switch 51 is switched by a switching signal from the reset pulse drive control circuit 50.
The φR portion supplied from the drive pulse generation circuit 41 to the driver 42 is stopped within the blanking period other than the video period.

The signal amplified by the differential preamplifier 43 is as shown in FIG. 2A when the φR portion is stopped for a certain period in the blanking period other than the video period by the switching signal from the reset pulse drive control circuit 50. In the blanking period after the video period in which the
There is a φR stop section where the R section does not exist (the output of the image sensor in FIG. 2A is actually the differential preamplifier 43).
Is used in the same meaning as the output of. In addition, in FIG. 2A, a signal in which the video portion has a positive polarity is shown, but it can also be applied to a signal having a negative polarity).

Further, in FIG. 2A, as in the case of FIG. 24, each pixel in the output of the image pickup device has a configuration in which the φR portion is added to the image portion shown by hatching. Also, one horizontal period is represented by 1H.

The output of the differential preamplifier 43 is input to the clamp circuit 52, which is clamped at the level of the φR stop portion by the clamp pulse of the clamp circuit 52 shown in FIG. Done this φ
The signal of the image part where the level of the R stop part is 0 level is extracted.

The level of this φR stop portion is almost equal to the black level. A timing signal for generating a clamp pulse is input to the clamp circuit 52 from the reset pulse drive circuit 50, and a plump pulse is generated within a period of the switching signal. CD like this
Instead of using the S circuit, the signal component of the image part is extracted by black level clamping.

The signal clamped by the clamp circuit 52 is input to the dimming signal generating circuit 53, and the signal detected by the detecting circuit in the dimming signal generating circuit 53 and averaged, that is, the DC signal EE signal 54 is generated. And this EE
The signal is input to the diaphragm control circuit 21 in the light source device 3. Then, the aperture control circuit 21 controls the opening / closing amount of the aperture 7 to perform automatic light control.

According to the present embodiment, the output signal of the image pickup device 10 is passed through the isolation means to the CD on the secondary circuit side.
In addition to the configuration for inputting to the S circuit 45, the image sensor 10
The output signal of is clamped to the level of the period during which the φR portion is stopped in the patient circuit, and the φR portion is removed by extracting the signal component of the video portion by performing direct current reproduction. An EE signal that does not include a part can be generated.

That is, since the EE signal can be generated without interposing the high frequency circuit such as the modulation circuit 31, the photocoupler 32, and the demodulation circuit 33 in the conventional example shown in FIG. It is possible to generate an EE signal having a small number and good characteristics such as a delay in transmission.

Further, in the present embodiment, since the modulation circuit 31 of FIG. 23 is not necessary, noise that is likely to be generated from this modulation circuit does not leak to the patient circuit side, so that the shield between the patient circuit and the secondary circuit is eliminated. EMC can be simplified and the circuit that radiates noise to the external device side can be reduced.
Measures become easy.

In FIG. 2, a φR stop portion is provided in each blanking period in each 1H period, and a clamp pulse is output from each φR stop portion to perform black level clamping, thereby performing DC reproduction of the black level. Although it is performed, the black level clamp may be performed by outputting a clamp pulse once in a specific blanking period of at least several to several tens of 1H. Alternatively, a black level clamp may be performed by outputting a clamp pulse once in a specific blanking period other than the video period in one field or one frame period, and the value may be sample-held.

(Second Embodiment) FIGS. 3 to 5 relate to a second embodiment of the present invention, and FIG. 3 shows an electronic endoscope apparatus 1B according to a second embodiment of the present invention. 4 shows the configuration of the reset pulse canceling circuit, and FIG. 5 shows the operation explanatory diagram of the second embodiment. This electronic endoscope apparatus 1B is shown in FIG.
The configurations of the electronic endoscope apparatus 1A and the video processor 4B are partially different, and the same components as those of the video processor 4A are denoted by the same reference numerals.

In this embodiment, the drive signals φH1, H2φ, φR, etc. output from the drive pulse generation circuit 41 in the video processor 4B are applied to the image pickup device 10 via the driver 42, and these drive signals φH1, H2φ,
The image sensor is driven by application of φR or the like, and outputs a photoelectrically converted signal.

The photoelectrically converted signal is amplified by the preamplifier 43 'and then transmitted from the patient circuit to the secondary circuit side through the isolation transformer 44 as in the case of FIG.
It is input to the CDS circuit 45 and the PLL circuit 46, and the sampling pulse 48 of the pulse generation circuit 47 causes the CDS
The circuit 45 samples the video portion, removes the φR portion to extract the baseband signal component, and the video processing circuit 49
The standard video signal generated in is input to the monitor 5,
Display an image of the part to be examined. In this embodiment, the reset pulse drive control circuit 50 and the switch 51 in the first embodiment are not provided.

Therefore, as shown in FIG. 24 or FIG. 5A, since the output signal of the image pickup element 10 normally has φR on the side opposite to the image side, the black level clamp is left as it is. Difficult to do. Therefore, in the present embodiment, the reset pulse canceling circuit 61 is provided to cancel the reset pulse or the φR portion. The φR canceling means will be described with reference to FIGS. 4 and 5.

As shown in FIG. 4, the signal obtained by amplifying the output signal of the image pickup device 10 by the preamplifier 43 'is passed through the AC coupling capacitor C1 connected to the input terminal thereof, and the base of the PNP transistor Q1 constituting the emitter follower circuit. Applied to. This base is grounded via a resistor R1 and is also grounded via a diode D1 in the reverse direction. The collector of the transistor Q1 is grounded, and the emitter is connected to the positive power supply terminal Vcc via the resistor R2.

Further, this emitter is connected to the output terminal through the series circuit of the diode D2 and the resistor R3 in the forward direction, and this output terminal is grounded through the parallel circuit of the resistor R4 and the capacitor C2. There is. Next, the operation of the reset pulse canceling circuit 61 will be described.

The output signal of the image pickup device amplified by the preamplifier 43 'is shown in FIG. This signal is the capacitor C
In 1, the direct current coupling with the former stage is canceled, and the anode is grounded with respect to the negative part of the input signal.
1 is conducted, and the lower end portion of the negative polarity portion (the lower end portion of the signal is shown by Sa as shown in the partially enlarged view of FIG. 5A) is diode clamped to the GND level (or the ground level). It

The signal clamped by the diode is passed through the emitter follower circuit formed by using the transistor Q1 and then detected by the diode D2, the resistor R3, and the capacitor C2 to cancel the φR portion, and the waveform shown in FIG. 5B is obtained. The signal of can be generated.

As for the signal shown in FIG. 5 (B), the signal before detection indicated by the dotted line is a diode D2 as shown in a partially enlarged view.
By using the detection, the waveform becomes like a solid line and the φR portion can be canceled out.

The level of the lower end portion Sb of FIG. 5 (B) becomes substantially equal to the black level. This reset pulse cancellation circuit 6
The output signal of 1 is input to the clamp circuit 52 of FIG.
The level of the lower end portion Sb of FIG. 5B is clamped by the clamp pulse output from the clamp circuit 52 during the blanking period. That is, as shown in FIG. 5C, the level of the lower end portion Sb of FIG. 5B is clamped by the clamp pulse, and the image portion can be extracted as in the case of performing the black level clamp.

The reset pulse canceling circuit 61 shown in FIG.
The image pickup device output signal (more specifically, the output signal of the preamplifier 43 ') input to is passed through an inverting circuit in the preamplifier 43' or the like to be a signal whose image portion becomes larger than φR as shown in FIG. Has been done.

As described above, it is possible to extract almost the same video signal component as that obtained by performing the black level clamp without the CDS circuit, and the clamped signal is detected by the dimming signal generating circuit 53. By performing the average photometry, the EE signal of the DC signal can be obtained. The effect of this embodiment is almost the same as that of the first embodiment.

(Third Embodiment) Next, a third embodiment of the present invention will be described. As described above, the image pickup device 10 has the drive signal φH output from the drive pulse generation circuit 41.
Driven by each pulse of 1, φH2, φR, etc., photoelectric conversion is performed. As shown in FIG. 24 or FIG. 5A, the output signal of the image pickup device 10 is normally φR on the side opposite to the image side.
Since there is a part, it is difficult to clamp the black level as it is.

In this embodiment, the output of the preamplifier 43 'is input to the dimming signal generating circuit 53 via the clamp circuit 52' in FIG. The structure of this clamp circuit 52 'is shown in FIG.

The output signal of the preamplifier 43 'is applied to the base of the PNP type transistor Q2 via the capacitor C3 connected to the input terminal. This base is connected to the negative power supply terminal −Vcc via a resistor R5, and is also grounded via a series circuit of a forward diode D3 and a switch S1. The collector of the transistor Q2 is grounded, and the emitter is connected to the positive power source terminal Vcc via the resistor R6.
And the output terminal of the clamp circuit 52 '.

The switch S1 is the clamp circuit 4
ON by the clamp pulse of the 3'clamp pulse generation circuit
It is set to / OFF. In this embodiment, as shown in FIG. 7A, the clamp pulse shown in FIG. 7B is output during the blanking period other than the video signal.

When this clamp pulse is at a high level, the switch S1 is turned on and the diode D3 causes G
Clamp to the ND level so that the same result as when performing the black level clamp is obtained. The switch S
When 1 is OFF, the output signal of the image sensor applied to the base of the transistor Q2 is GND when the level at the upper end of the signal in the blanking period (black level equivalent portion Sc shown in the enlarged view of FIG. 7A) is GND. It is assumed that it is set to be higher than the level.

The configuration other than this clamp circuit 52 'is shown in FIG.
Is the same as Next, the operation of the clamp circuit 52 'will be described.

Imaging device 1 amplified by preamplifier 43 '
The output signal of 0 is as shown in FIG. 7A, and in the blanking period other than the video period of the video section, as shown in the enlarged view,
The signal portion at the upper end of the portion adjacent to the φR portion becomes the black level corresponding portion Sc corresponding to the black level.

Then, the capacitor C3 of the clamp circuit 52 'is galvanically separated from the preceding stage side and applied to the base of the transistor Q2. The switch S1 is turned on by the clamp pulse shown in FIG. 7B which is output during the blanking period other than the video signal, and the diode D3 is turned on at the black level corresponding portion Sc to bring the black level corresponding portion Sc to the GND level. It is clamped, and the video part is extracted and output to the output end.

In this way, it is possible to extract an image portion that is almost the same as that generated by black level clamping without the CDS circuit. The clamped signal is input to the dimming signal generating circuit 53, detected and averaged for photometry. As a result, the DC signal EE signal can be obtained.

As described above, according to the first to third embodiments, it is possible to provide an electronic endoscope apparatus which is excellent in terms of EMC while maintaining the performance of automatic light control and minimizing the scale of the patient circuit. There is an effect that it can be provided.

(Fourth Embodiment) Next, an electronic endoscope apparatus according to a fourth embodiment having a function of correcting the cable length will be described with reference to FIG. The electronic endoscope apparatus whose main part has a configuration shown in FIG. 8 has the same basic configuration as that of the electronic endoscope apparatus 1B shown in FIG. 3, for example. In the present embodiment, the information indicating the length of the cable is detected, and the fluctuation of the propagation delay time and the waveform level of the image sensor (specifically CCD) output signal, the image sensor drive signal due to the difference in the cable length, and the like. It is an electronic endoscope apparatus that prevents image deterioration due to

As shown in FIG. 8, an electronic endoscope 72 having an image pickup device (specifically, CCD) 10 as an image pickup means built in at the tip thereof is connected to the image pickup device 10 via a cable 73 as a signal transmission means. The vertical drive signal φV, the horizontal drive signal φH, and the reset signal φR are supplied. The electronic endoscope 72 also includes a light guide (not shown) that transmits illumination light and emits it from the front end surface.

Here, the reset signal φR and the horizontal drive signal φH (more specifically, the two-phase horizontal drive signals φH1 and φH)
H2) has a waveform as shown in FIG. Reset signal φ
R includes a reference duty 50% signal generated by the timing pulse generator 4 (hereinafter, referred to as SSG) for detecting the length of the cable, and is included in one horizontal synchronization period of the horizontal synchronization signal. The video signal section and the cable length detection pulse section are divided and superposed intermittently.

Then, the video processor 74 as the image processing means receives drive pulses such as the vertical drive signal φV, the horizontal drive signal φH, and the reset signal φR which are drive pulses for driving the image pickup device 10 and various timing pulses. A timing pulse generation circuit 75 for generating is provided, and the cable 7 is passed through a level correction circuit 76 which passes through the driver 42 and is controlled by information on the length of the cable.
3 is supplied.

Here, the timing pulse generation circuit 75
Uses a programmable element capable of rewriting data, and is controlled by the changeover switch S2 to read the data in the ROM 77 as a memory means for writing the stored data in the timing pulse generating circuit 75,
Data is being rewritten. Further, the changeover switch S2 may be changed over according to the type of the image pickup device 10 and the type of the electronic endoscope 72.

Further, the driving power source VDD is supplied from the reference power source 78 to the image pickup device 10 and the driver 42 through the cable 79. Here, the reference power source 78 is a commercially available 3
This can be realized by using a terminal regulator IC or the like. In this case, there are various types depending on the maximum output current. However, in the electronic endoscope 72 and the like, an abnormal mode in which the signal line is short-circuited at the tip of the insertion portion Even if the maximum output current is 100
If the current is about mA, the heat generated by it will not be a problem even considering the effect on the human body. Furthermore, the above 3
According to the application example of the terminal regulator IC, it is possible to set a predetermined maximum current value by combining the regulator ICs.

On the other hand, the image pickup signal output from the image pickup device 10 is transmitted to the non-inverting input terminal of the differential amplifier 81 in the video processor 74 via the cable 80, and the other inverting input terminal is connected to the patient circuit. It is connected to GND. Further, the in-phase and anti-phase amplified image pickup signals are output from the differential amplifier 81 to drive the isolation transformer 44 as an isolation means, and the output of the isolation transformer 44 is output to the differential amplifier 83 on the secondary circuit side. I have received it. With this configuration, it is possible to suppress the common mode noise mixed in from the outside in the common mode.

The in-phase image pickup signal output from the differential amplifier 81 is passed through a limiter amplifier 84 in order to correct a change in the image pickup element drive pulse level caused by a change in the length of the cables 73 and 80. Is waveform-shaped, and the phase is compared with the continuous reference duty 50% pulse input to the phase comparator 85 and output from the timing pulse generation circuit 75.

That is, the duty 50% pulse of FIG. 9 output from the timing pulse generating circuit 75 (see FIG. 10).
(See (B)) and this pulse (see FIG. 10A) delayed by the lengths of the cables 73 and 80 (waveform-shaped by the limiter amplifier 84) are input to the phase comparator 85,
The phase comparator 85 outputs a propagation delay time error signal such that a pulse is output only during a period corresponding to the time difference between the rising portions of both signals (see FIG. 10C).

The output signal of the phase comparator 85 is input to the mask circuit 86 which is controlled by the mask signal output from the timing pulse generating circuit 75, and the video signal portion is masked as shown in FIG. 10 (D). 10) The cable length detection pulse portion is extracted and input to the smoothing circuit 87, and smoothing is performed by this smoothing circuit 87 as shown in FIG. The S / H circuit 88 controlled by the sample hold pulse (S / H pulse) shown in FIG.
Then, the voltage of that portion is held and the cable length level correction voltage signal is obtained.

A level correction circuit 76 for correcting the level of the image pickup element drive pulse with this cable length level correction voltage signal.
Then, the level correction circuit 76 automatically controls the level of the image pickup element drive pulse according to the level value of the cable length level correction voltage signal. FIG.
Reference numeral 0 indicates a timing chart for explaining the operation of correcting the cable length.

Here, when the correction cable range is expanded and the propagation delay time is equal to or longer than one cycle of the reference duty 50% pulse, the phase comparator erroneously detects, so that one cycle of the reference duty 50% pulse is detected. Is widened, that is, the frequency of the superposed clock is divided to lower the frequency, and then the superposed and phase comparison is performed on the reset signal φR.

On the other hand, the output signal of the differential amplifier 83 is CDS.
The CDS circuit 4 is input to the circuit 55 and the PLL circuit 46.
In 5, the CDS pulse is generated by the clock output from the PLL circuit 46 that generates the clock that follows the propagation delay due to the cable length, the CDS pulse is supplied to the pulse generation circuit 47, and the sampling pulse 48 from the pulse generation circuit 47 is generated.
Then, the output signal of the image pickup device 10 is subjected to correlated double sampling, converted into a video signal by the video processing circuit 49, and output to the monitor side.

The output of the differential amplifier 81 in the patient circuit is input to the clamp circuit 61 as in FIG. 3, and is clamped during the cable length detection pulse portion other than the video signal period to display the video portion. After being extracted, it is input to the dimming signal generating circuit 53 and detected to generate the EE signal 54, and this EE signal 54 is input to the aperture control circuit 21 of the light source device 3 shown in FIG.

In the present embodiment, a stable output signal of the image pickup device 10 can always be obtained irrespective of the difference in the lengths of the cables 73 and 80 and the fluctuation of the signal delay time due to the isolation means. With the configuration, it is possible to correct the change in the drive pulse level applied to the image pickup device 10 caused by the change in the cable length. Further, the same effect as that of the second embodiment is obtained with respect to the dimming function.

(Fifth Embodiment) FIG. 11 shows an electronic endoscope apparatus 111 capable of performing stable synchronization between an insulated patient circuit and a secondary circuit by means of isolation means. It is a block diagram which shows the structure of a principal part. Here, the configuration and the operation will be sequentially described.

As shown in FIG. 11, the electronic endoscope apparatus 11
1 has an electronic endoscope (hereinafter abbreviated as scope) 112 and a video processor 113. Video processor 113
Drive pulse generator circuit (hereinafter abbreviated as SSG_1) 1
Reference numeral 14 generates a drive pulse for driving an image sensor 116 (specifically, CCD) provided at the tip of the scope from an output of a crystal oscillator (hereinafter, referred to as CXO) 115,
The voltage is applied to the image sensor 116 via the driver 117.

Here, as shown in FIG. 12, the reset signal φR, which is one of the drive pulses, is divided into the effective video signal portion and the invalid video area during one cycle of the horizontal synchronizing signal (abbreviated as 1H period). It is divided and formed so as to have different waveforms, and a duty 50% pulse, which is an index signal for phase correction of the cable length of the scope 112, is superimposed on the invalid video region.

An image pickup signal which is a signal output from the image pickup element 116 driven by such a reset signal φR is
Du including the phase error due to the cable length as shown in FIG.
ty 50% pulse is output, and the video processor 113
It is input to the internal preamplifier 118.

The image pickup signal amplified by the preamplifier 118 is input to the isolation transformer 119 which insulates the patient circuit from the secondary circuit, is insulated, and is transmitted to the secondary circuit side. The transmitted signal is input to the CDS circuit 120 and the blanking circuit (abbreviated as BLK circuit) 121. First, the image pickup signal input to the BLK circuit 121 is generated from the SSG_1114 and is transmitted (to the secondary circuit) via the photo-coupler 122 that is insulated and transmitted from the patient circuit to the secondary circuit. H.BLK), the duty 50% pulse portion is extracted.

Here, H. The pulse width of BLK is narrower than the width at which the duty 50% pulse portion is superimposed, considering delay due to cable length, variation in the photocoupler 122, or temperature error (see FIG. 12). Further, the output of the BLK circuit 121 is input to a PLL circuit 123, which controls a voltage of a voltage controlled oscillator (hereinafter, referred to as VCXO) 124 to generate a clock and a timing pulse generation circuit which generates a timing pulse in synchronization with this clock. (Hereinafter, abbreviated as SSG_2) Phase comparison with the output of 125,
By performing the PLL operation, the output clock phase of the VCXO 124 is changed to 50% Duty output from the image sensor 116.
It is designed to follow the phase of the waveform of the pulse part.

Based on the tracked clock of the VCXO 124, a sampling pulse 126 is generated in SSG_2125, and the sampling pulse 126 causes the CDS circuit 120 to perform correlated double sampling (CDS) on the output of the image pickup signal. Get the video signal of.

Further, this SSG_2125 is VCX.
A sync signal 128 for a video signal is generated from the output of O124 and the frame reset pulse 127 by the frame reset extraction circuit 130, and the sync signal 128 is input to the video processing circuit 129.
The output of the circuit 120 is subjected to video signal processing, converted into a standard video signal, and output to a monitor (not shown). Here, regarding the extraction of the frame reset pulse 127, FIG.
This will be described with reference to FIG.

As shown in FIG. 13, during two cycles (frame period) of the vertical synchronizing signal, the reset signal φR in the image sensor drive pulse has frame index information (or 1H period) existing in one frame. A 50% inversion duty pulse is superimposed as a frame index signal. The image pickup signal output from the image pickup device 116 driven by such a reset signal φR is as shown in FIG.
As shown in, the output is performed with the inverted duty of 50% stored.

When the output of the image pickup device is input to the CDS circuit 120, only the 50% inversion duty part has a positive polarity output, and the other parts have a negative polarity output. This extraction method is disclosed in the above-mentioned fourth embodiment or Japanese Patent Application Laid-Open No. 6-70216 by the present applicant.

That is, here, the frame index information managed in units of clocks superimposed on the image pickup signal output is extracted. For example, when the frame index information is transmitted separately from the image pickup device output. In comparison, there is an advantage in that there is no timing error due to variations in the transmission system (particularly isolation means), resulting in unstable synchronization.

The output of the preamplifier 118 is input to the clamp circuit 61 and the dimming signal generating circuit 53, the EE signal 54 is generated, and is input to the aperture control circuit of the light source device (not shown).

By the way, when the extracted frame index information is transmitted by the isolation transformer 119 which is an isolation means, it is affected by radiation noise from a high-frequency scalpel device or the like used in an endoscopic examination.

Therefore, in the present embodiment, SSG_
Vertical blanking signal (V.BL generated at 1114)
K) is received by the photocoupler 122 and transmitted to the secondary circuit,
The configuration is such that it is supplied to the frame reset extraction circuit 130. The frame reset extraction circuit 130 receives the supplied vertical blanking signal V.V. The BLK performs an operation of masking the output signal of the CDS circuit other than the frame index information.

As shown in FIG. 13, the vertical blanking signal V. BLK includes the duration of the frame index information and is active for a longer time than this time. Then, even if noise is mixed in the output signal of the CDS circuit 120 during a period other than the frame index information, it is possible to prevent the frame reset pulse 127 from being generated at an incorrect timing due to the mask operation described above.

Further, the frame reset extraction circuit 130
Binarizes the masked output signal of the CDS circuit 120 and outputs SSG_2125 as a frame reset pulse 127.
Output to As a result, SSG_1114 and SSG_2
It is possible to extract 125 frame periods more stably.

At this time, the SSG_2125 can adopt a configuration in which the frame reset signal 127 is accepted only once in five frames and the other frames are internally reset. According to such a configuration, the frame reset signal 127 is buried in noise per frame period, and the frame reset extraction circuit 130 is
It is possible to output the synchronization signal from SSG_2125 even if it is not output from SSG_2125.

As described above, according to this embodiment, even when the cable length of the scope 112 must be taken into consideration, the patient circuit side and the secondary circuit side can be reliably synchronized, and a high-frequency scalpel device, etc. Even when both are used together, it is possible to prevent an image from flowing due to disturbance of synchronization. Further, regarding the function of light control, there is the same effect as in the second embodiment. In the present embodiment, when the scope is not connected, the frame reset signal 127 is not output, and thus synchronization cannot be established.

Next, FIG. 14 shows a configuration in which synchronization can be achieved even when the scope is not connected, and a menu screen and a color bar can be generated. The same components as those described in FIG. 11 are designated by the same reference numerals, and the description thereof will be omitted. First, in order to output the menu screen or the color bar to the monitor, the menu screen generation or the color bar signal generated from the CPU 141 is generated by the switching signal from the keyboard (not shown) or the front panel SW, and the video processing circuit 12.
The signal from 9 is switched by the switching circuit 142, and CP
U141 is the synchronization signal 128 from SSG_2125,
The timing of the menu screen generation and the color bar is created.

If the scope 112 is pulled out (that is, the image pickup signal is not output), the frame reset signal cannot be extracted and synchronization cannot be established. In order to eliminate this, the isolation transformer 119
The output of the imaging device having the φR portion or the reset portion carrier after the output is integrated by the carrier integration circuit 143, and the carrier detection circuit 144 detects the carrier to generate the scope connection detection signal 150.

Then, this scope connection detection signal 150
When the scope 112 is connected by controlling the switch 146, the output of the PLL circuit 123 is selected,
When not connected, the output of the reference power supply 145 is selected and input to the VCXO 124. When there is no image sensor output, the VCXO 124 is used to generate a fixed reference clock, and the SSG is generated by the reference clock.
Even if the synchronization signal is output from the _2125 and the scope 112 is not connected, the menu screen and the color bar can be generated without displaying an image that is not visible.

The scope connection detection signal 150 can also be detected by using the signal from the scope detection terminal at the contact point of the connecting portion between the scope 112 and the video processor 113 described above. For this configuration, the scope discrimination circuit 93 of FIG. 18 described later can be used. However, although three types of scopes are discriminated in FIG. 18, this may be used for discriminating whether or not a scope is connected, instead of the type of scope.
When using this scope discrimination circuit 93,
It is necessary to insulate the detected signal from the patient circuit to the secondary circuit by using a photocoupler (not shown) or the like. Therefore, it can be said that the method shown in FIG. 14 can automatically detect the connection of the scope on the secondary circuit side without increasing the number of photocouplers.

(Sixth Embodiment) By the way, when different scopes using image pickup devices having different numbers of pixels and different element structures can be physically connected to the same video processor, that is, the image pickup devices and When the scope lineup increases as the technology changes, and video processors that support this increase at the same time, the scope using a new image sensor is physically connected to the existing video processor. Is equivalent to this, but in combination with a scope of a new image sensor (for example, when the number of pixels is different or the element structure is different) in which the drive signal and signal processing circuit of the video processor do not match, Although the processed image is not output, some image is output, so if the operator inserts the scope into the patient without noticing it. If, disconnect the scope once, again,
This results in reinsertion, which is not preferable in terms of loss of examination time and pain for the patient at the time of insertion.

In order to solve this problem, the electronic endoscope apparatus having a structure in which the driving of the image pickup device is switched to stop the output of the image pickup device or set the black level when the combination that should be prohibited is made. Will be described below.

The electronic endoscope apparatus 201 shown in FIG.
Before explaining the configuration of A, the existing electronic endoscope apparatus 201B
The configuration will be described with reference to FIG. FIG.
The existing electronic endoscope apparatus 201B shown in (B) is a scope 20 in which a CCD 210B as an image sensor is incorporated.
2B, the video processor 203B to which the scope 202B is connected, and the video processor 203B
And a monitor 205 for displaying a standard video signal output from the signal processing circuit 204B incorporated in the.

In the video processor 203B, C
Timing pulse generator (hereinafter referred to as SSG) 214B for generating a pulse for driving the CD 210B
Then, a signal processing circuit 204B that receives the output of the CCD 210B driven by the pulse and performs signal processing is built in, and a standard video signal is output from the signal processing circuit 204B to the monitor 205. The terminals T1 to T6 of the connector of the scope 202B are connected to the terminals Ta to Tf of the connector receiver of the video processor 203B, respectively.

The terminals T1 to T6 of the connector are drive terminals and output terminals for driving the CCD 210B by the signal lines in the scope 202B, that is, φH, φV1, φV2.
.phi.V4, .phi.V3, connected to the CCD output (Out) (for simplification, the same sign as the drive signal applied as the drive terminal is shown).

When the connector is connected to the connector receiver, the drive signals φH and φV of SSG214B are sent.
1, φV2, φV4 and φV3 are normally applied to the drive terminals φH, φV1, φV2, φV4 and φV3 of the CCD 210B, and the output signal output from the output terminal Out of the CCD 210B is input to the signal processing circuit 204B. ing.

The drive signals φH, φV1, φV2, φV4 and φV3 for driving the CCD 210B will be described. The CCD 210B will be described assuming that there are horizontal transfer pulses φH and four types of vertical transfer pulses φV1 to φV4 as drive signals. FIG. 16A shows a timing chart when the CCD 210B is driven (FIGS. 16A and 16B are also operation explanatory diagrams of FIG. 15A).

Regarding the vertical charge transfer, FIG.
6B, the electric potentials of .phi.V1 to .phi.V4 are applied to the vertical transfer register 221 for vertical charge transfer at the timings shown in FIG. The state of the charge temporarily accumulated at the middle level at the timing is represented by the timing from t1 to t9 as shown in FIG. 16B, and is transferred in the direction of the horizontal transfer register 222. Horizontal transfer register 2
The charges transferred to 22 are transferred to an output section (not shown) by the horizontal transfer pulse φH and output as a CCD output.

On the other hand, in the electronic endoscope apparatus 201A shown in FIG. 15A, a new scope 202A incorporating a new CCD 210A having a different number of pixels, for example, from the CCD 210B as an image pickup element, and the scope 202A and the scope 202B. Video processor 20 for connection
3, a monitor 205 for displaying a standard video signal output from the signal processing circuit 204 incorporated in the video processor 203, and a light source device for supplying illumination light to a light guide (not shown) of the scope 202A. Have.

In the video processor 203, a scope discrimination circuit 211 for discriminating the connected scopes 202A and 202B, and a CCD 210A built in the scope discriminated by the scope discrimination circuit 211.
Alternatively, a timing pulse generator (hereinafter referred to as SSG) 214 for generating a pulse for driving 210B
And the CCD 210A or 2 driven by the pulse
A signal processing circuit 204 that receives the output of 10B, performs signal processing, and outputs a standard video signal to the monitor 205 is incorporated.

This signal processing circuit 204 has, for example, a configuration similar to that of the video processor 4B of FIG. 3, generates a control signal for controlling dimming in the patient circuit, and outputs it to the aperture control circuit of the light source device. , Automatically control the amount of illumination light (illumination light intensity).

The terminals Ta to Tf of the connector receiver of the video processor 203 are respectively connected to the terminals T1 to T6 of the connector of the scope 202A or 202B. Further, the terminals T1 to T6 of the connector of the scope 202A are drive terminals and output terminals for driving the CCD 210A by signal lines, that is, φH, φV1, φV4, φV.
2, φV3, CCD output (Out).

That is, the scope 202A is characterized in that it has a connection structure in which the scope 202B and the drive terminals φV2 and φV4 connected to the terminals T3 and T4 are exchanged.

When, for example, the connector of the scope 202A is connected to the connector receiver, the scope discrimination circuit 211 discriminates that it is the scope 202A, and the drive signals φH, φV1, φV2 of the SSG 214 are detected.
φV4 and φV3 are driving terminals φH and φV of CCD 210A
1, φV2, φV4, φV3 are normally applied to the CCD
The output signal output from the output terminal Out of 210A is input to the signal processing circuit 204.

Further, the scope 202B is used as a connector receiver.
When the connector of is connected, the scope discrimination circuit 2
11 determines that the scope is 202B, and S
Drive signals φH, φV1, φV2, φV4 of SG214
φV3 is the drive terminal of CCD 210B φH, φV1, φV
2, φV4, φV3 are normally applied, CCD210B
The output signal output from the output terminal Out of is input to the signal processing circuit 204.

When normally applied in this way, FIG.
As described above with reference to FIGS. 6A and 16B, normal pixel transfer is performed. FIG. 15 (A)
According to the electronic endoscope apparatus 201A shown in FIG. 2, both scopes 202A and 202B can be operated normally.

On the other hand, the video processor 203B of the existing electronic endoscope apparatus 201B is mistakenly erroneously driven by this video processor 203B or signal processing cannot be performed correctly (it is not a combination to be connected), which is a new scope 202.
When A is connected, a vertical drive pulse (in which φV2 and φV4 in FIG. 16A are interchanged) as shown in FIG. 17A is applied to the drive terminals φV1 to φV4 of the CCD 210A. It will be.

FIG. 17B shows the state of vertical transfer of charges at each timing of t1 to t9 in FIG. 17A. Similar to the above description, as shown in FIG. 17B, the accumulated charges are sequentially transferred to the vertical transfer register 221 at the timings of t1 to t9, but normal transfer, that is, in the direction of the horizontal transfer register 222 is performed. The charges are transferred in the opposite direction to the transfer, and the charges are discarded outside the vertical transfer register 221.

That is, when the scope 202A incorporating the new CCD 210A is connected to the existing video processor 203B which does not correspond to this CCD 210A, C
As in the case where no light is incident on the CD 202A, only the dark signal (black signal) is output, and as a result, the monitor screen becomes dark (nothing is output), and the operator mistakes the scope 202A. As a result, it is possible to avoid insertion into a patient and prevent the above-mentioned troubles in advance.

Further, according to the present apparatus, the existing scope 2
When the new scope 202A is connected to the existing video processor 203B without the need for extra terminals, the image is displayed as described above. You can turn it off.

In the above description, the CCD 210A and CCD
In the case of 210B, the drive terminals φV2 and φV4 are replaced with each other, and when a new CCD 210A is connected to the video processor 203B which is not compatible with this CCD 210A, the output signal is changed so that the vertical transfer is reverse transfer. Although not obtained, the horizontal transfer may be reversed.

For example, as a driving signal for horizontal transfer, φH1,
When φH2 is used, the existing scope 202B and the new scope 202B have a connection structure in which the driving terminals of φH1 and φH2 are exchanged, and in the case of a combination that should be prohibited, the horizontal transfer is reversed. The signal should be swept away. Further, in the combination that should be prohibited, both the vertical transfer and the horizontal transfer may be reversed.

According to the above structure, the new scope 2 to be commercialized will be manufactured without any modification to the existing video processor 203B which has already been commercialized.
02A has the effect of solving the above-mentioned problems.

In FIG. 15A, the existing scope 2
02B and the new scope 202A has been described as having a video processor 203 capable of supporting both, but in the case of an electronic endoscope apparatus having a video processor (203A for convenience) only capable of handling the new scope 202A (this video The configuration of the processor 203A includes an SSG and a signal processing circuit corresponding to the scope 202A. Further, it is assumed that the configuration of the connector receiver is the same as that of FIG. In the case of a combination that should be prohibited such that the scope 202B of No. 2 is connected, an image is not displayed, and thus it is possible to prevent use in such an incorrect combination.

Next, with respect to the number of types of scopes, the number of terminals for scope detection is smaller and the number of terminals can be easily discriminated with a simple circuit configuration. Alternatively, the scope discrimination circuit may be configured as shown in FIG.

As shown in FIG. 18, there are three types of scopes 2A, 2B, and 2C. Scope 2I
(I = A, B, C) are connectors 91a, 91, respectively.
It has b and 91c and can be connected to the connector 93 of the processor 92.

The connectors 91a, 91b, 91c drive an image pickup device such as a CCD provided at the tip of the scope.
A drive pulse and a power source, a terminal (not shown) for transferring a video signal output from the image sensor, detection terminals 96a, 96b, 96c for discriminating the type of scope, and power source terminals for detection 97a, 97b, 97c, and GND terminal 98
a, 98b, 98c are provided for each scope 2I, and the detection terminals 96a, 96b, 96 are provided.
All the terminals of c are connected to one corresponding detection terminal 99 in the connected video processor 92.

Here, the detection terminal 96a of the scope 2A
Is connected to the detection power supply terminal 97a on the scope side by a lead wire or the like, while nothing is connected to the detection terminal 96b of the scope 2B and is in an open state, and the detection terminal 96c of the scope 2C is , GND terminal 98c is connected by a lead wire or the like.

Further, the video processor 92 will be described. The video processor 92 has a connector 95 connected to the scope 2I and a scope discrimination circuit 93 connected to it. The connector 95 includes the detection power supply terminal 100, the detection terminal 99, and the GND similarly to the scope 2I.
The terminal 101 is provided. Here, the power supply terminal for detection 10
A detection power source (hereinafter referred to as Vdd) is connected to 0, and a GND terminal 101 is connected to GND. Here, as the scope detection circuit 93, the following may be considered.

As shown in FIG. 18, resistors R11 and R12 are connected in series between Vdd and GND, and the midpoint thereof is connected to the detection terminal 99. Therefore connector 9
If nothing is connected to 5 but is not connected, resistor R1
The voltage divided by the resistors 1 and R12 is the detection signal 10
4 is applied to the non-inverting input terminal of the comparator 105 and the inverting input terminal of the comparator 106.

A resistor R13 is connected between Vdd and GND.
, R14, R15 are connected in series, a reference voltage 107 for comparing the detection signal 104,
108 are formed, and are applied to the inverting input terminal of the comparator 105 and the non-inverting input terminal of the comparator 106, respectively. In FIG. 18, the resistors R11 and R12 have almost the same resistance value, and the resistors R13, R14, R
It is also assumed that the resistance values of 15 are substantially equal to each other.

Next, the operation will be described. Now, assuming that the scope 2A is connected to the video processor 92, the detection power supply terminal 97a of the scope 2A is connected to the detection terminal 96a on the scope side. The voltage Vdd appears as the signal 104. This detection signal 104 (voltage Vdd in this case)
Is input to the comparators 105 and 106, the reference voltage 1
07 and 108, respectively, to determine whether the voltage is “H” or “L” depending on the magnitude of the voltage, and output as 2-bit digital signals DA1 and DA2 (scope 2A
In this case, the digital signals DA1 and DA2 are "H" and "L" respectively). FIG. 19 shows a detection signal voltage of each scope and a truth table of discrimination results.

Here, the power source for detection is separate from Vdd and the power source for driving the image pickup device, but if they are the same, the number of terminals can be further reduced and the size of the connector can be made smaller. That is, there is an effect that a large number of types of scopes can be easily discriminated with a smaller number of detection terminals and a simple circuit configuration.

Incidentally, for example, in the first embodiment, the image pickup device 10 is built in the electronic endoscope 2 arranged at the image forming position of the objective lens 9 at the distal end portion of the insertion portion. An optical endoscope which transmits an optical image by an objective lens instead of the mirror 2 by an image guide as an image transmitting means, and an optical image which is attached to the optical endoscope and transmitted by the image guide is formed. The same can be applied to an endoscope equipped with a TV camera including a TV camera having a built-in image pickup element.

In the first embodiment, for example, the EE signal 54 for dimming is used to output the aperture 7 through the aperture control circuit 21.
Although the amount of illumination light is adjusted by controlling the opening / closing amount of, the amount of illumination light may be controlled by adjusting the voltage or current of the driving power source of the lamp 6. It should be noted that embodiments and the like configured by combining the above-described embodiments and the like in a partial manner also belong to the present invention.

[Additional Notes] 1. Illuminating means for irradiating the body cavity with the examination light, imaging means for converting an optical image of a subject illuminated by the examination light into an electric signal, and leakage current insulation for transmitting the output signal of the imaging means. Isolation means, correlation double sampling means for performing correlation double sampling on the output signal of the imaging means transmitted by the isolation means, and processing of the output signal of the correlation double sampling means for input to a display device. A signal processing means for generating a possible video signal, and a control signal used for automatic dimming of the illuminating means from an output signal of the imaging means before transmission by the isolation means. An electronic endoscope apparatus comprising: a dimming signal generating unit for controlling the electronic endoscope.

[0136] 2. The electronic endoscope device is a drive unit that generates a drive pulse for driving the image pickup unit, and the drive pulse is generated in a specific blanking period other than a video period of an output signal of the image pickup unit. The reset signal output is stopped, the dimming signal generating means clamps the output signal of the image pickup means before transmission by the isolation means in the specific blanking period, and The electronic endoscope apparatus according to appendix 1, further comprising means for detecting a signal clamped by the clamp means.

3. The dimming signal generating means includes a reset pulse removing means that removes a reset pulse component included in a drive pulse for driving the image pickup signal in a specific blanking period other than a video period of the output signal of the image pickup means. A clamp means for clamping the output signal of the image pickup means before transmission by the isolation means in the specific blanking period, and a means for detecting the signal clamped by the clamp means. The electronic endoscope apparatus according to appendix 1.

[0138] 4. 4. The electronic endoscope apparatus according to appendix 3, wherein the reset pulse removing means is an upper end clamp means for clamping an upper end portion of the reset pulse component existing in the specific blanking period. 5. 4. The electronic endoscope apparatus according to appendix 3, wherein the reset pulse removal means is a diode detection means that short-circuits a reset pulse component existing in the specific blanking period to a ground level with a diode.

6. A video processor device connectable to an endoscope having an imaging means for converting an optical image of a subject into an electric signal for observing the inside of a body cavity of the subject, comprising the following components: a. Drive circuit for driving the image pickup means: This drive circuit generates a drive pulse for driving the image pickup means, and the drive pulse is in a period other than the video period of the output signal of the image pickup means. It includes a cable length detecting pulse train for detecting the cable length of the cable connecting the image pickup means and the video processor section. b. Isolation means: A means for transmitting the output signal of the image pickup means, which is input to the video processor device, to a leakage current and transmitting it to the next stage. c. Signal processing means: Correlation double sampling means for performing correlation double sampling of the output signal of the image pickup means insulated and transmitted by the isolation means, and signal processing of the output signal of the correlation double sampling means to obtain a standard television. A video signal generating means for converting the video signal into a format is included. d. Phase comparison means: for comparing the phase of the cable length detection pulse train included in the drive pulse output from the drive circuit a with the phase of the component corresponding to the cable length detection pulse included in the output signal of the imaging means. is there. e. Level correction means: The level correction means corrects the level of the drive pulse output from the drive circuit a according to the output signal of the phase comparison means. And a driving circuit a, a phase comparison means b, and a level correction means e are arranged on the endoscope side of the isolation means b.

7. A video processor device to which an endoscope having an imaging means for converting an optical image of a subject into an electrical signal can be connected in order to observe the inside of a body cavity of the subject, and which includes the following components a to g. a. Drive circuit for driving the image pickup means: the drive circuit generates a blanking pulse having a duration corresponding to at least one of a horizontal synchronizing signal and a vertical synchronizing signal of the image pickup means, and outputs the image pickup means. A reset pulse train for resetting the amplification unit is generated, and the reset pulse train is a period other than the video period of the output signal of the image pickup unit, for at least one of the horizontal synchronizing signal and the vertical synchronizing signal of the image pickup unit,
It includes a sync signal detection pulse train that occurs only during its duration. b. First isolation means: A means for transmitting the output signal of the image pickup means, which is input to the video processor device, to the next stage while insulating the leakage current. c. Signal processing means: the first isolation means b
Correlation double sampling means for performing correlation double sampling of the output signal of the image pickup means, which has been insulated and transmitted, and a video signal for converting the output signal of the correlation double sampling means into a video signal of a standard television format. Including generating means. d. Extraction means: Extracts the active period of the sync signal from the sync signal detection pulse train included in the output signal of the correlated double sampling means. e. Second isolation means: The blanking pulse generated by the driving circuit a is insulated from the leakage current and transmitted to the next stage. f. Blanking processing means: The output signal of the extracting means d is subjected to blanking (masking) processing by the blanking pulse insulated and transmitted by the second isolation means e. g. Synchronous signal generating means: means for generating a horizontal synchronizing signal and a vertical synchronizing signal which accompany the video signal of the standard television format generated by the signal processing means c, and which has been subjected to blanking processing by the blanking processing means f. Thus, the horizontal and vertical sync signals are generated in synchronization with the sync signal of the drive circuit a.

8. A video processor device to which an endoscope having an image pickup means for converting an optical image of the subject into an electric signal in order to observe the inside of a body cavity of the subject is connectable, the endoscope being connectable to the electric signal. Is output as a video signal in a standard television format, and when the electrically incompatible endoscope is connected to the video processor, the image pickup means of the endoscope stops outputting or An electronic endoscope apparatus comprising drive changing means for driving the image pickup means so as to output a dark signal.

9. The drive changing means drives the image pickup means such that at least one of a vertical transfer operation and a horizontal transfer operation of the image pickup means corresponds to a reverse transfer operation in response to connection of the incompatible endoscope. Characteristic Note 8
The described electronic endoscope apparatus. 10. The drive changing means changes the connection state of a plurality of drive pulse signals for driving the image pickup means between an endoscope adapted to the video processor device and an incompatible endoscope. The electronic endoscope apparatus according to appendix 9.

11. The processor device includes a drive circuit that outputs a plurality of drive pulses that drive the imaging unit,
Adaptation of the endoscope, detection means for detecting incompatibility, and when the detection result of this detection means is incompatibility, the order of the plurality of drive pulses output by the drive circuit is changed to 11. The electronic endoscope apparatus according to appendix 10, wherein the image pickup means has a drive re-changing means for performing a normal transfer operation for both the vertical transfer operation and the horizontal transfer operation.

12. Illuminating means for irradiating the body cavity with the examination light, imaging means for converting light information into an electric signal, isolation means for insulating the input side and the output side, and an output signal of the isolation means are correlated double. In an electronic endoscope apparatus having a means for sampling and a means for processing the signal after the correlated double sampling and outputting it to a display device, the illumination means and automatic dimming control are performed from the signal input to the isolation means. An electronic endoscope apparatus, wherein a control signal for performing the operation is created and output as a patient circuit.

13. By the driving means for driving the image pickup means, in a specific blanking period other than the video portion,
By stopping the reset pulse driving of the driving pulse of the image pickup unit, a unit for stopping the generation of the reset pulse unit in the output signal of the image pickup unit during a specific blanking period other than the image portion, 13. The electronic endoscope apparatus according to appendix 12, further comprising: a means for clamping a portion whose generation has been stopped, and a means for detecting the clamped signal.

14. 13. The electronic device as set forth in appendix 12, further comprising, as means for clamping an output signal of the image capturing means, means for clamping an upper end of a specific blanking period other than a video portion and means for detecting the clamped signal. Endoscopic device.

15. A reset pulse existing in the output signal of the image pickup unit is offset by at least a specific blanking period other than the video portion, a unit by which the reset pulse portion is offset is detected, and the clamped signal is detected. 13. The electronic endoscope apparatus according to appendix 12, further comprising: 16. As means for canceling the reset pulse portion,
16. The electronic endoscope apparatus according to appendix 15, wherein at least a specific blanking period other than the image portion is diode-detected.

17. A plurality of scopes having various lengths, each having a solid-state image sensor for receiving an optical image and converting the image signal, and a drive circuit for connecting the scopes and generating a drive signal for driving the solid-state image sensor; A video processor unit having an image signal processing circuit for processing an image signal generated from the solid-state image pickup device; and the video processor unit, after isolating the image signal by an isolation means, and then performing correlated double sampling. In an electronic endoscope apparatus having a signal processing means for performing (CDS), processing the signal after the CDS, and outputting the processed signal to a display device, a signal for detecting the cable length is output to a portion other than the video signal of the drive signal. A position for comparing the phase of the signal for detecting the cable length included in the image signal with the phase before the superposition by intermittently superimposing, driving the solid-state imaging device. A level for compensating the fluctuation of the drive signal level due to the cable length by the comparison means, the smoothing means for smoothing only the intermittent signal portion for detecting the cable length, and the means for holding the smoothed voltage. 17. An electronic endoscope apparatus characterized in that a correction means is provided in front of the isolation means. It is an electronic endoscope apparatus for connecting an electronic endoscope including a solid-state image sensor for converting optical information into an electric signal, wherein the electronic endoscope apparatus receives an image pickup signal from the electronic endoscope and inputs the signal. Input to the isolation means for insulating the output side from the output side, means for performing correlated double sampling using the output signal of the isolation means, and signal processing after the correlated double sampling, and output to the display device In the electronic endoscope apparatus having the signal processing means for performing, a frame serving as a reference for driving the solid-state image pickup device, pulse generating means for generating a vertical synchronizing signal, and horizontal and vertical pulse from the pulse generating means. Superimposing means for superimposing at least phase timing on the drive signal, and phase timing of at least one of the horizontal and vertical pulses from the output from the isolation means. Extraction means for extracting, as said superimposed. A blanking pulse corresponding to at least one phase timing of the horizontal and vertical pulses is further generated from the pulse generating means, the blanking pulse is transmitted through the second isolation means, and the blanking pulse is extracted. An electronic endoscope apparatus having a blanking processing means for performing a blanking process on the phase timing by the transmitted blanking pulse.

19. In an electronic endoscope system in which multiple scopes using image sensors with different numbers of pixels and different element structures can be connected to the same video processor, if the combination is prohibited, the drive of the image sensors is changed to output the image sensor. The electronic endoscope device characterized by stopping or turning off the dark signal. 20. 20. The electronic endoscope apparatus according to appendix 19, wherein the means for changing the drive of the image pickup device causes vertical transfer to reverse horizontal transfer.

21. Multiple scopes that use image sensors with different numbers of pixels and different element structures can be connected to the same video processor, and video connected to scopes with the drive signal lines of the image sensors switched to prevent combination A video processor, characterized in that the processor can determine the type of the image pickup device and switch the drive signal of the image pickup device to a normal state to obtain a video signal.

[0151]

As described above, according to the present invention, the illumination means for irradiating the examination light into the body cavity, and the imaging means for converting the optical image of the object illuminated by the examination light into an electric signal. An isolation means for insulating a leakage current and transmitting an output signal of the image pickup means; a correlated double sampling means for correlated double sampling the output signal of the image pickup means transmitted by the isolation means; In an electronic endoscope apparatus having a signal processing means for processing an output signal of a correlated double sampling means to generate a video signal that can be input to a display device, an output signal of the imaging means before transmission by the isolation means From the above, by providing the dimming signal generating means for generating the control signal used for the automatic dimming of the illuminating means, the patient circuit on the upstream side of the isolation means is provided. To implement the functions of the automatic light control with a small circuit scale, so that can also simplify EMC measures.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall configuration of an electronic endoscope apparatus according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of an operation of the first embodiment.

FIG. 3 is a block diagram showing an overall configuration of an electronic endoscope apparatus according to a second embodiment of the present invention.

FIG. 4 is a circuit diagram showing a configuration of a reset pulse cancellation circuit.

FIG. 5 is an operation explanatory diagram of the second embodiment.

FIG. 6 is a circuit diagram showing a configuration of a clamp circuit according to a third embodiment of the present invention.

FIG. 7 is an operation explanatory diagram of the third embodiment.

FIG. 8 is a block diagram showing a configuration of a main part of a fourth embodiment of the present invention.

FIG. 9 is a waveform diagram showing a waveform of a signal applied to the image sensor.

FIG. 10 is an operation explanatory diagram of generating a signal for correcting the cable length.

FIG. 11 is a block diagram showing a configuration of a main part of a fifth embodiment of the present invention.

FIG. 12 is an explanatory diagram showing a signal form output from the image sensor.

FIG. 13 is an operation explanatory diagram of the fifth embodiment.

FIG. 14 is a block diagram showing a configuration of a main part of a modified example of the fifth embodiment.

FIG. 15 is a block diagram showing an electronic endoscope apparatus and the like according to a sixth embodiment of the present invention.

FIG. 16 is an operation explanatory diagram of a drive signal applied to the CCD and charge transfer in the case of a normal combination.

FIG. 17 is an operation explanatory diagram of a drive signal and charge transfer applied to a CCD in the case of a combination that should be prohibited.

FIG. 18 is a configuration diagram showing a configuration of a scope discrimination circuit and the like.

FIG. 19 is a diagram showing a truth table for explaining the operation of FIG. 18;

FIG. 20 is a block diagram showing a configuration of a conventional electronic endoscope apparatus.

FIG. 21 is a diagram showing an example of transmission of an EE signal.

FIG. 22 is a diagram showing another example of transmission of an EE signal.

FIG. 23 is a block diagram showing a configuration of a conventional electronic endoscope apparatus.

FIG. 24 is a waveform diagram showing an output signal of the image sensor.

[Explanation of symbols]

 1A ... Electronic endoscope device 2 ... Electronic endoscope 3 ... Light source device 4A ... Video processor 5 ... Monitor 6 ... Lamp 7 ... Aperture 8 ... Light guide 9 ... Objective lens 10 ... Imaging element 21 ... Aperture control circuit 41 ... Driving Pulse generation circuit 42 ... Driver 43 ... Differential amplifier 44 ... Isolation transformer 45 ... CDS circuit 46 ... PLL circuit 47 ... Pulse generation circuit 49 ... Video processing circuit 50 ... Reset pulse drive control circuit 52 ... Clamp circuit 53 ... Dimming signal Making circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kiyoshi Tsuji 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside Olympus Optical Co., Ltd.

Claims (1)

[Claims] 1. An illuminating means for irradiating a body cavity with examination light, an imaging means for converting an optical image of a subject illuminated by the examination light into an electric signal, and a leakage current to isolate the leakage current from the imaging means. Isolation means for transmitting an output signal, correlation double sampling means for performing a correlation double sampling on the output signal of the imaging means transmitted by the isolation means, and processing an output signal of the correlation double sampling means. A signal processing means for generating a video signal that can be input to a display device, and an automatic dimming of the illumination means from an output signal of the imaging means before transmission by the isolation means. An electronic endoscope apparatus having a dimming signal generating means for generating a control signal to be used.