JPS5969040A - Endoscope - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an endoscope that is equipped with a solid-state image sensor and is capable of automatically preventing blooming due to specular reflection.

Conventionally, general endoscopes have been equipped with an optical finder, but with this configuration, only the operator can observe the image of the affected area, so it is inconvenient to use it for lectures, etc. Since images must be recorded using a silver halide camera, the amount of recording is limited and only still images can be recorded. Therefore, in order to solve these problems, a solid-state image sensor such as a COD and an electronic viewfinder made of an LCI (liquid crystal display element) or a CRT are incorporated into the operation unit, and the electric current obtained by the solid-state image sensor is incorporated into the operation unit. It was considered to guide the signal to an electronic viewfinder, monitor TV, etc. via a camera control unit and record it on a recording device, but if a solid-state image sensor was used, blooming due to specular reflection would occur on the screen of the electronic viewfinder, etc. As a result, a clear image cannot be obtained at 0tl, making observation partially impossible.

Furthermore, the fact that it is impossible to observe even if it is caused by agitation or effusion makes observation inaccurate and reduces medical safety.

In view of the above-mentioned problems, the present invention provides a system in which a transmissive liquid crystal display element, which is driven in the same manner as the solid-state image sensor, is mounted on the light-receiving surface of the solid-state image sensor, and a pixel with the solid-state image sensor When the amount of incident light exceeds the saturation level, this is detected and the transmittance of the corresponding pixel of the liquid crystal display element is reduced to reduce the transmittance of the pixel of the solid-state image sensor.・Reducing the amount of incident light to below the saturation level,
This aims to provide an endoscope that prevents the occurrence of blooming on the screen of the moon finder, etc., but this will be explained based on one embodiment illustrated below. , 1 is the operating section of the endoscope, 2 is an image guide (optical fiber bundle) whose output end is guided into the operating section 1, and 3 is a terminal disposed on the output end side of the image guide 2 within the operating section 1. An image lens, 4 is a solid-state image sensor on which the light emitted from the image guide 2 located in the operation unit 1 is formed into an image by an imaging lens 3, 5 is a solid-state image sensor 4
6 is a light guide guided from a light source device (not shown) to the distal end of the endoscope; 7 is an operating unit 1;
This is an electronic viewfinder fixed to the rear of the camera. 8 is a preamplifier that amplifies the input signal from the solid-state image sensor 4; 9 is a camera control unit that converts the input signal from the preamplifier 8 into an image signal; 1 (1; J: image signal from the camera control unit 9); 11 is a monitor television that displays the image signal from the camera control unit 9 as an image.
12 is a synchronization signal generation circuit; 13 is a synchronization signal generation circuit 12
A solid-state image sensor driving circuit 14 drives the solid-state image sensor 4 according to an input signal from the synchronizing signal generating circuit 12, and when there is an input from a comparator described later, '+Liquid crystal display elements and drive circuits that reduce the transmittance of moving pixels;
15 compares the potential of the output of the preamplifier 8 and the saturation voltage VT1□ of the solid-state image sensor 4, and determines that the potential is the saturation voltage Vi'll
This is a comparator that outputs an output (--FIG. 2) when the voltage exceeds 1, and sends the output to the liquid crystal display element drive circuit 14.

The endoscope according to the present invention is constructed as described above, and since the liquid crystal display element 5 is in a transparent state during normal observation, the light related to the image of the affected area emitted from the image guide 2 is transmitted to the imaging lens 3. The light enters the light-receiving surface of the solid-state image sensor 4 via the liquid crystal display element 5 and is converted into an electric signal.The electric signal is amplified by the preamplifier 8 and converted to an image signal by the camera control unit 9, and then sent to the electronic viewfinder 7 and the monitor. It is sent to the television 12 and displayed as an image, and
It is recorded in the recording device 10 as necessary.

If specularly reflected light that causes blooming is incident on a certain pixel of the solid-state image sensor 4, this will appear as a peak in the output waveform generated by the solid-state image sensor 4 (see Figure 2). ), which is amplified by the preamplifier 8 and then input to the connominator 15. if,
If this input voltage is higher than the saturation voltage of the solid-state image sensor 4, an output is generated from the connominator 15 and sent to the liquid crystal display element drive circuit 14. Then, the liquid crystal display element drive circuit 14 causes the liquid crystal display element 5 to reduce the transmittance of the pixel being driven at that time.
operates in synchronization with the solid-state image sensor drive circuit 13, so this pixel corresponds to the pixel on which specularly reflected light is incident on the solid-state image sensor 4. Therefore, the amount of light incident on the pixels of the solid-state image sensor 4 is immediately reduced to below the saturation level, so that blooming on the screen of the electronic viewfinder 7 or the like is prevented from occurring. Therefore, a clear image can always be obtained in the electronic viewfinder 7, etc., making accurate observation possible, and the possibility of partial inability to observe can be minimized, resulting in high medical safety.

As mentioned above, the endoscope according to the present invention can automatically prevent the occurrence of blooming due to specular reflection, so it has important practical advantages in that accurate observation is possible and medical safety is high. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an electric circuit of an embodiment of an endoscope according to the present invention, and FIG. 2 is an output waveform diagram of a preamplifier of the above embodiment. ■...Operation unit, 2...Image guide, 3...Imaging lens, 4...Solid-state image sensor, 5...Liquid crystal display element, 6...Light guide, 7...Electronic viewfinder, 8
...Preamplifier, 9...Camera control unit, 10...Recording device, 11...Monitor TV, 1
2. Synchronization signal generation circuit, 13. Solid-state image sensor drive circuit, 14 Liquid crystal display element 7-11 trillion trend path, 15. Comparator. Continued from page 1 0 Inventor Yasuhiro Ueda Olympus Optical Industry Co., Ltd., 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inventor Susumu Nishigaki Olympus, 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inventor: Atsushi Olympus Kogyo Co., Ltd. 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inventor: Yutaka Yuzuki Olympus Kogyo Co., Ltd., 2-43-2 Hatagaya, Shibuya-ku, Tokyo Intra-company inventor Akira Nakamura Kawakira 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Industry Co., Ltd.

Claims (1)

[Claims] In an endoscope equipped with a solid-state image sensor, a transmissive liquid crystal display element that is driven in synchronization with the solid-state image sensor is closely arranged on the light-receiving surface of the solid-state image sensor, and a pixel of the solid-state image sensor is An endoscope characterized in that when the amount of incident light exceeds a saturation level, this is detected and the transmittance of the pixel of the liquid crystal display element corresponding to the pixel is reduced.