JP3091288B2 - Electronic endoscope device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a processing configuration of an electronic endoscope KagamiSo location for performing for image display to the video signal obtained by the solid-state imaging device.

[0002]

2. Description of the Related Art Electronic endoscope devices used in the medical and industrial fields are well known.
For example, an electronic endoscope (electronic scope) is inserted into a body to be observed, such as a digestive tract, a structure, and the like, and the body to be observed is observed by a CCD (Charge Coupled Device) which is a solid-state imaging device provided at a distal end. Can be.

FIG. 9 shows a configuration of a conventional electronic endoscope apparatus. As shown, an electronic endoscope (electronic scope) 1 is detachably connected to an external processor apparatus 2 by a connector. Connected. In the distal end of the electronic endoscope 1,
A CCD 4 and a CCD driving circuit 5 optically connected to the observation window 3 are provided. On the other hand, an irradiation window 6 for irradiating observation light into the object to be observed and a light guide (optical fiber) for supplying light to the irradiation window 6. 7 is provided. Further, in the external processor device 2, a correlated double sampling (CDS-Correlated Double Sampling) circuit 9 is provided via a preamplifier 8 and connected to the CCD 4, and the CDS circuit 9 has a sampling pulse generation circuit. A sampling pulse is given from 10. The CDS circuit 9 is connected to a video signal processing unit 11 which performs gamma correction, white balance processing and the like, and has a memory and the like. Further, the electronic endoscope 1 includes a light source device 12 and a condenser lens 13, and the light source device 12 supplies predetermined light (RGB light in the case of a frame sequential method) to the light guide 7 of the electronic endoscope 1.

According to the above configuration, the light output from the light source device 12 is radiated from the irradiation window 6 of the electronic endoscope 1 into the object to be observed, and the image of the object to be observed is displayed on the observation window. The video signal is captured by the CCD 4 driven by the CCD driving circuit 5 via the CCD 3. The video signal output from the CCD 4 is supplied to the CDS via the preamplifier 8.
The CDS circuit 9 supplies a signal to the CCD 9
4 is clamped, and a video signal portion containing image information is sampled and held. In this case, the sampling process is performed based on the output of the sampling pulse generation circuit 10, and the sample and hold process is performed by the sampling pulse phase-adjusted in relation to the clamp pulse. The noise inside is well reduced.

[0005] The output of the CDS circuit 9 is output to a monitor connected to the external processor device 2 after gamma correction processing and the like are performed in the video signal processing section 11.
In this way, an image of the inside of the body to be observed is displayed in color on the monitor.

[0006]

However, in the signal processing circuit of the conventional electronic endoscope apparatus, when using the electronic endoscope 1 of different length, the video signal output from the CCD 4 is clamped. There is a problem that the timing of the sample hold is different, and the CDS circuit 9 cannot be effectively operated. That is, conventionally, there are electronic endoscopes 1 of various lengths depending on the application target portion, and when the electronic endoscopes 1 of different lengths are connected to the external processor device 2, the lengths thereof are different. It is necessary to supply the sample pulse and the like to the CDS circuit 8 at an operation timing in consideration of the time of the video signal transmitting the CDS. In this case, it is conceivable to provide a circuit or the like for switching the operation timing in correspondence with various types of electronic endoscopes 1. However, this will complicate the circuit and make the replacement of the electronic endoscope 1 complicated. .

The present invention has been made in view of the above problems, and has as its object to provide a correlated double sampling circuit or the like without converting operation timing even when using electronic endoscopes of different lengths. An electronic endoscope device that operates effectively, simplifies the circuit configuration, and is easy to handle.
To provide a location .

[0008]

According to a first aspect of the present invention, an electronic endoscope having a built-in solid-state image sensor and having a different length is connected to an external processor.
In an electronic endoscope apparatus configured to be connectable, a sample-and-hold circuit that samples and holds a video signal obtained by the solid-state imaging device, and a sample-and-hold circuit.
Sampling pulse generation time to supply sampling pulse
Path for adjusting the phase of the sampling pulse.
An adjustment circuit as well as disposed to the operation portion or the connector portion of the electronic endoscope, to the operating section or the connector portion, the
When adjusting the phase of the adjustment circuit from outside, the adjustment circuit
A lid opening / closing means for exposing the portion is provided .
The invention according to a second aspect is characterized in that a drive circuit for driving the solid-state imaging device is provided together with a sample and hold circuit in an operation section or a connector section of an electronic endoscope.

[0009]

According to the above arrangement, the sample hold circuit , the sampling pulse generation circuit, and the adjustment circuit are provided on the operation board or the setup board in the connector section.
This makes it possible to easily form a sampling pulse at a timing corresponding to the length of each electronic endoscope. Therefore, when connecting different types of electronic endoscopes to the external processor device, it is not necessary to pay attention to the operation of the sample and hold circuit.

In the above case, a driving circuit for driving the CCD can be provided together with the sample and hold circuit.
In this case, the circuit configuration can be simplified, and the influence of the generated heat, for example, which is caused by placing the drive circuit at the distal end, can be prevented.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1, the electronic endoscope KagamiSo location according to the first embodiment
In the figure, an electronic endoscope (electronic scope) 14 is connected to an external processor device 15.
At the tip of the electronic endoscope 14, the CCD 4 is connected to the observation window 3 via an optical system member 16, and an operation unit 17 is provided at a substantially intermediate portion of the electronic endoscope 14. Although not shown in FIG. 17, angle knobs and freezes for bending the distal end of the electronic endoscope 14 up and down, left and right,
A control button for hard copy or the like is arranged. In the first embodiment, the operation unit 17 includes a C
A DS circuit 18 and a sampling pulse generation circuit 19 are provided.

The connector section 2 of the electronic endoscope 14
0, a setup board 21 for setting or adjusting conditions necessary for video signal processing is provided, and an external processor 1 connected via the setup board 21 is provided.
5, a video signal processing unit 23, a timing pulse generation circuit 24, and the like are provided.

FIG. 2 shows a circuit configuration in the CDS circuit 18. The CDS circuit 18 includes an amplifier 26,
The capacitor Cc and the amplifier 27 are connected in series,
Immediately after the capacitor Cc, a reference power supply Vc is connected in parallel via a switching circuit 28, and a clamp pulse output from the sampling pulse generation circuit 19 in FIG. An amplifier 30 is connected to the amplifier 27 via a gate circuit 29. A capacitor CH is connected in parallel immediately after the gate circuit 29, and the output from the sampling pulse generating circuit 19 is output to the gate circuit 29. A sampling pulse is provided. This sampling pulse is correlated with the clamp pulse and is a timing pulse whose phase has been adjusted, whereby correlated double sampling is performed. The clamp pulse and the sampling pulse are formed based on a timing pulse corresponding to a specific length of the electronic endoscope in which the sampling circuit is provided.

The first embodiment has the above circuit configuration, and its operation will be described with reference to FIG. The image of the object to be observed can be captured by the CCD 4 through the observation window 3 of FIG.
The output of the CCD 4 is directly input to the CDS circuit 18. The output of the CCD 4 is, as shown in FIG. 3A, a reset pulse 100, a feed-through section (black level) 101, and a video signal section 102 containing video information.
Consists of Then, in this CDS circuit 18,
The clamp pulse shown in FIG. 2B and the sampling pulse shown in FIG. 2C are input from the sampling pulse generation circuit 19, and when the clamp pulse is given to the switching circuit 28 in FIG. 101 is DC-regenerated by the reference voltage Vc. After a predetermined time, the sampling pulse is applied to the gate circuit 2
9, whereby the video signal unit 102 is sampled and held.

Since the sampling pulse has a correlation with the clamp pulse, the output video signal of the CCD 4 is correlated double-sampled to obtain a video signal from which noise has been effectively removed. As described above, in the first embodiment, the CDS circuit 18 and the sampling pulse generation circuit 19 are provided in the operation unit 17 to realize the sampling operation of the video signal corresponding to the inherent length of the electronic endoscope 14. It becomes possible.

FIG. 4 shows an example in which a delay difference noise elimination circuit similar to the correlated double sampling circuit is used as the sample and hold circuit. In the figure, each circuit is provided so that one output of the amplifier 32 is connected to the positive terminal of the operation amplifier 33 and the other output is connected to the negative terminal of the operation amplifier 33 via the delay line 34. In the operating amplifier 33, the output signal of the CCD 4 and the delay line 34
The noise component is removed by subtracting the signal (FIG. 5) delayed by the time τ in FIG. A gate circuit 35 is connected to the operation amplifier 33, and a low-pass filter (LPF) 36 is connected to the gate circuit 35. A sampling pulse is supplied from the sampling pulse generation circuit 19 to the gate circuit 35. Configuration.

According to this example, the diagram (a) shown in FIG.
(B) is subtracted from the CCD output of FIG. 1B. Therefore, the video signal section 102 subtracts the feedthrough section 101, so that noise existing in the feedthrough section 101 serving as a reference level is removed. In this way, noise mixed in the video signal can be removed. Then, the video signal section 102 is sampled and held in the gate circuit 35 based on the sampling pulse, and the delay difference noise elimination circuit also extracts a good video signal having the same result as the correlated double sampling. Becomes possible.

Next, the arrangement of the sample and hold circuit of the first embodiment in the operation section will be described with reference to FIG. That is, the illustrated operation unit 17 is sized to be held with one hand,
An angle knob (rotating body) 38 for bending the distal end portion of the electronic endoscope 14 is provided, and a photographing button 39 and the like are provided. A circuit board 41 is mounted on the apex of the operation unit 17 and a circuit board storage unit 42 is disposed therein. The CDS circuit 18 and the sampling pulse generation circuit 19 are mounted on the circuit board 41.

A male screw part 43 is formed in the circuit board housing part 42, and a cap 45 having a female screw part 44 screwed to the male screw part 43 is detachably attached. Therefore, by removing the cap 45, the phase adjustment of the sampling pulse generation circuit 19 on the circuit board 41 is facilitated. That is,
In the sample and hold circuit, it is necessary to adjust the phase of the sampling pulse at the time of manufacturing or the like. This phase adjustment and the like can be easily performed by the configuration of the detachable cap 45 described above.

FIG. 7 shows the configuration of a second embodiment of the present invention. In the second embodiment, a sample and hold circuit is provided in a connector section 20. That is,
The setup board 47 in the connector section 20 of FIG.
A DS circuit 48 and a sampling pulse generating circuit 49 are provided. In this case also, a sample hold circuit is provided on the electronic endoscope 14 side, which corresponds to the length of each electronic endoscope 14. The clamp pulse and the sampling pulse of the operation timing thus determined can be uniquely determined.

Although the circuit shown in FIG. 2 is used as the CDS circuit 48, the delay difference noise elimination circuit shown in FIG. 4 can be applied, and the structure of the second embodiment can be applied to the first embodiment. As in the example, it is possible to obtain a video signal from which noise has been effectively removed by a correlated double sampling operation or the like.

Next, a third embodiment of the present invention will be described with reference to FIG. In the third embodiment, a pulse drive circuit, a waveform shaping circuit, and a power supply circuit are provided in an operation unit 17 together with a sample and hold circuit. That is, a driving circuit for driving the CCD 4 provided at the tip of the electronic endoscope 14 is also provided on the electronic endoscope 14 side, and the individual CCDs are provided.
4 is performed.

In FIG. 8, a circuit board 41 (FIG. 6) arranged on the operation unit 17 is provided with a CDS circuit 18 and a sampling pulse generation circuit 19, a waveform shaping circuit 51, and horizontal register clocks φH1, φH2. Φ1 and φH2 drive circuits 52 for driving the imaging section clocks φ1 to φ1
4 and a φS1 to φS4 drive circuit 54 for driving the storage section drive clocks φS1 to φS4. Further, a power supply VDD circuit 55 for forming and outputting a power supply VDD, and other DC power supply circuits are provided. These drive circuits 52, 53, 54 and the power supply circuit are connected to the CCD 4.

According to the configuration of the third embodiment, the horizontal register clocks φH1 and φH2 supplied from the timing pulse generation circuit 24 of the external processor device 15, the imaging unit clocks φ1 to φ4, and the storage unit driving clocks φS1 to φS4. Is supplied to each of the drive circuits 52, 53, 54,
The CCD 4 is driven by the drive circuits 52, 53, 54. Note that the horizontal register clock φH1 is also output to the sampling pulse generation circuit 19, and a sampling pulse is formed based on this.

Conventionally, there is a device in which the drive circuit and the power supply circuit are disposed at the distal end of the electronic endoscope 14. In this case, however, there is a problem that the diameter of the distal end is increased by the drive circuit and the like. In addition, there is a problem that the performance of the solid-state imaging device is deteriorated due to heat generated by the drive circuit and the like. However, in the third embodiment, the drive circuit and the power supply circuit are connected to the operation unit 1.
7, the above problem can be solved and a reliable device can be provided. Also,
As shown in FIG. 6, since the circuit board 41 can be easily exposed by the detachable cap 45, it is easy to check the drive circuit and the like and to replace the board.

In the third embodiment, the driving circuit and the power supply circuit of the CCD 4 are operated together with the sample and hold circuit together with the operation unit 1.
7, these circuits can be arranged on the setup board 47 of the connector section 20 together with the sample and hold circuit.

[0027]

As described above, according to the first aspect of the present invention, a sample and hold circuit for sampling and holding a video signal obtained by a solid-state imaging device, and a sampling
Since the loose generation circuit and the adjustment circuit are disposed in the operation section or the connector section of the electronic endoscope, if the operation timing of the sample and hold circuit is set in accordance with each length in various electronic endoscopes, Various electronic endoscopes can be used without adjusting the operation timing for each different type. As a result, the circuit configuration is simplified and handling is facilitated. According to the lid opening and closing means,
It will be easier to adjust the phase of the sampling pulse at times
There are advantages.

According to the second aspect of the present invention, the drive circuit for driving the solid-state imaging device is provided together with the sample and hold circuit in the operation section or the connector section of the electronic endoscope. A reliable video signal processing operation can be ensured by preventing the influence of heat by the circuit.

[Brief description of the drawings]

1 is a diagram showing a configuration <br/> configuration of the electronic endoscope KagamiSo location according to the first embodiment of the present invention.

FIG. 2 is a circuit diagram showing a configuration in a CDS circuit of the first embodiment.

FIG. 3 is a waveform chart showing an operation in the CDS circuit of FIG. 2;

FIG. 4 is a circuit diagram showing a configuration of a delay difference noise elimination circuit which is another example of the sample and hold circuit in the first embodiment.

FIG. 5 is a waveform chart showing an operation of the delay difference noise elimination circuit of FIG. 4;

FIG. 6 is a diagram showing a mounting structure of a circuit board in an operation unit in the first embodiment.

FIG. 7 is a diagram showing a configuration of a second exemplary embodiment of the present invention.

FIG. 8 is a diagram showing a configuration of a third embodiment of the present invention.

FIG. 9 is a diagram showing a configuration of a signal processing circuit in a conventional electronic endoscope device.

Claims (2)

(57) [Claims] 1. A solid-state imaging device having a built-in image sensor having a different length.
The electronic endoscope is configured to be connectable to an external processor device.
That in the electronic endoscope apparatus, a sample hold circuit for sampling and holding a video signal obtained by the solid-state imaging device, the sample hole
Sampling circuit that supplies a sampling pulse to the
Adjust the phase of the pulse generator and the sampling pulse
And an adjustment circuit for controlling the operation of the electronic endoscope.
In addition to the adjustment section, the operation section or the connector section
Cover that exposes the adjustment circuit when performing adjustment from outside
An electronic endoscope apparatus provided with an opening / closing means . Wherein the driving circuit for driving the solid-state imaging device with the sample and hold circuit, the first claim, characterized in that arranged to the operating portion or the connector portion of the electronic endoscope
The electronic endoscope device according to claim 1 .