JPH07313449A - Electronic endoscopic device - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide an electronic endoscope apparatus in which an image output terminal can be provided together with a monitor output terminal with a simple circuit configuration. [Structure] A video signal output from a solid-state image pickup device 4 of an endoscope insertion section is digitized, divided into three color signals of red, green, and blue and stored in a memory 18R, and then a digital-analog converter 19R ... Are converted into analog again, and the analog video signals for each color output from the digital-analog converters 19R ... Are converted into gamma correction circuits 23R.
Is sent to the monitor output terminal 13, and the image processing output terminal 14 is provided so as to be branched from the output end of the analog-digital converter 19R.

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 which displays an observation image on a monitor by a video signal sent from a solid-state image pickup device provided in the endoscope.

[0002]

2. Description of the Related Art In an electronic endoscope apparatus, an observation image is displayed on a monitor. However, in order to make the image easy to see without a feeling of discomfort, a gamma correction process and a contour enhancement process are performed on a video signal sent to the monitor. Done.

Conventionally, a gamma correction circuit and an enhancement circuit for performing such gamma correction processing and contour enhancement processing are provided in an analog signal line sent from a solid-state image pickup device.

Then, the video signal which has undergone the gamma correction process and the edge enhancement process is converted into a digital signal by an analog-digital converter, and three color signals of red (R), green (G) and blue (B) are obtained. Separately stored in the memory, the signal output from the memory is converted back into an analog signal by the digital-analog converter and output to the monitor.

[0005]

By performing various image processing on the video signal of the electronic endoscope apparatus, there is a possibility that the diagnostic ability will be dramatically improved.

However, in order to perform image processing, it is desirable that the video signal which is the basis of the video signal is a raw signal. Therefore, before the video signal is input to the gamma correction circuit and the enhancement circuit, the output terminal for image processing is used. It is necessary to branch from the signal line of.

Therefore, in the conventional electronic endoscope apparatus as described above, it is necessary to branch from the video signal line from the solid-state image pickup device. As a result, monitor output of an analog-digital converter on the branch line, a memory for storing signals for each of the three colors, and a digital-analog converter for returning the signal output from each memory to an analog signal again Since it has to be installed separately from the one for use, the circuit configuration is complicated and the cost is high.

Therefore, an object of the present invention is to provide an electronic endoscope apparatus in which an image output terminal can be provided in parallel with a monitor output terminal with a simple circuit configuration.

[0009]

In order to achieve the above object, the electronic endoscope apparatus of the present invention converts a video signal output from a solid-state image pickup device provided in an endoscope into a digital signal. Analog-to-digital converter, a memory for storing the digital video signals output from the analog-to-digital converter separately for each of the three color signals of red, green, and blue, and for each color output from the memory. A digital-analog converter for converting a digital video signal into an analog signal, and a gamma correction circuit and enhance for performing gamma correction processing and contour enhancement processing on the analog video signal for each color output from the digital-analog converter Circuit and a monitor output terminal provided in the output section after passing through the gamma correction circuit and the enhancement circuit for displaying an image on the monitor. , Characterized by providing an image processing output terminal provided branched from the output terminal of the digital-to-analog converter in order to perform image processing.

[0010]

Embodiments will be described with reference to the drawings. FIG. 2 shows the overall configuration of the electronic endoscope apparatus according to the embodiment of the present invention. For example, at an image forming position of a subject by an objective optical system 3 provided at the tip of the insertion portion 2 of the endoscope 1, for example, Charge coupled device (C
The solid-state image sensor 4 made of CD) is built in. 5
Is a light guide fiber bundle for transmitting illumination light for illuminating an observation range, 6 is a video processor 10
Is a connector part connected to.

The video processor 10 also serves as a light source device for illumination, and the illumination light emitted from the light source lamp 11 is incident on the light guide fiber bundle 5 of the endoscope 1.

In the middle of the incident optical path, a three-color rotary filter 12 to which three color filters of red (R), green (G) and blue (B) are attached is arranged so as to rotate at a constant speed. Then, the illumination light of each color of red, green and blue is sequentially incident on the light guide fiber bundle 5 with a time shift.

In the video processor 10, a video signal processing circuit 15 for processing a video signal outputted from the solid-state image pickup device 4 and sent is provided. Further, outside the video processor 10, a monitor television 50 for reproducing and displaying an observation image of the endoscope and an image processing device 60 for performing various kinds of image processing on a video signal are provided.

The monitor television 50 and the image processing device 60 are connected to the monitor output terminal 13 and the image processing output terminal 14 which are connected to the output end of the video signal processing circuit 15 and are provided in the video processor 10. Has been done.

FIG. 1 shows a video signal processing circuit 15. The analog image pickup signal output from the solid-state image pickup device 4 is amplified by the amplifier 16 and then converted into a digital signal by the analog-digital converter 17.

The solid-state image pickup device 4 and the analog-digital converter 17 are driven in synchronization by a timing generator 21. Then, the analog-digital converter 17
Three memories 18R, 18 connected in parallel to the output terminals of the
G and 18B are also driven by the same timing generator 21, and the red (R) video signal is the first R memory 1
8R, the green (G) video signal is stored in the second G memory 18G, and the blue (B) video signal is stored in the third B memory 18B.

Each memory 18R, 18G, 18B
A digital-to-analog converter 1 in which the video signal for each color stored in
The signals are read by 9R, 19G, and 19B, and are output as analog video signals for each color.

Then, each color video signal is subjected to gamma correction processing by passing through the gamma correction circuits 23R, 23G and 23B, and then the enhancement circuits 24R and 24.
The contour enhancement processing is performed by passing through G and 24B.

Buffers 25R, 25G, and 25B are connected to the output terminals of the enhance circuits 24R, 24G, and 24B, and the output terminals of the buffers 25R, 25G, and 25B are connected to the monitor output terminals 13 for the respective RGB three-color video signals.
(13b) is connected.

In addition, the enhancement circuits 24R, 24G, 2
In the matrix circuit 26 branched and connected to the output terminal of 4B, the luminance signal Y and the color difference signal (R-
Y) and (B-Y) are created, which are input to the encoder 27 and converted into an NTSC or PAL composite video signal. The output terminal of the encoder 27 is connected to the monitor output terminal 13 (13a) for NTSC output or PAL output.

On the other hand, the video signals of the respective colors are assigned to the gamma correction circuit 23.
The signal lines branched from the output terminals of the digital-analog converters 19R, 19G, and 19B before being input to R, 23G, and 23B temporarily store the raw color video signals that have not been subjected to gamma correction and contour enhancement. Buffer 28
The R, 28G, and 28B are connected, and the output terminals of the buffers 28R, 28G, and 28B are connected to the image processing output terminal 14 for each of the RGB three-color video signals.

Therefore, to the monitor television 50 connected to the monitor output terminal 13, a video signal that has been subjected to gamma correction and contour enhancement is always output, and image processing connected to the image processing output terminal 14 is performed. For device 60,
A raw video signal without gamma correction and contour enhancement is always output.

Therefore, while performing the desired accurate image processing based on the raw video signal, in parallel with this, it is possible to observe a good quality observation image suitable for human vision on the monitor.

[0024]

According to the present invention, a video signal that has undergone gamma correction and contour enhancement is always output to the monitor output terminal, and gamma correction and contour enhancement are always performed to the image processing output terminal. Since a raw video signal that does not exist is output, while performing accurate image processing based on the raw video signal, in parallel with that, it is possible to observe a high-quality observation image suitable for human vision on a monitor. In addition, since it is not necessary to add an expensive device because the image processing output terminal is provided side by side, it can be realized at a very low cost.

[Brief description of drawings]

FIG. 1 is a circuit block diagram of an embodiment.

FIG. 2 is a schematic view of the overall configuration of the embodiment.

[Explanation of symbols]

 4 solid-state image sensor 13 monitor output terminal 14 image processing output terminal 17 analog-digital converter 18R, 18G, 18B memory 19R, 19G, 19B digital-analog converter 23R, 23G, 23B gamma correction circuit 24R, 24G, 24B enhance circuit

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[Procedure amendment]

[Submission date] February 14, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction content]

On the other hand, each color video signal is a gamma correction circuit 2
The buffers 28R, 28G, 28B are connected to the signal lines branched from the output terminals of the digital-analog converters 19R, 19G, 19B before being input to the 3R, 23G, 23B. An image processing output terminal 14 for each of the RGB three-color video signals is connected to the output end.

Claims (1)

[Claims] 1. An analog-digital converter for converting a video signal output from a solid-state image sensor provided in an endoscope into a digital signal, and a digital video signal output from the analog-digital converter is red. A memory for separately storing the three color signals of green, green and blue, a digital-analog converter for converting each color digital video signal output from the memory into an analog signal, and the digital-analog conversion After passing through the gamma correction circuit and the enhancement circuit for displaying the image on the monitor, the gamma correction circuit and the enhancement circuit for performing the gamma correction processing and the edge enhancement processing on the analog video signal for each color output from the device. Monitor output terminal provided in the output section of the and the output terminal of the digital-to-analog converter for performing image processing. Electronic endoscope apparatus is characterized by providing an image processing output terminals provided.