JPS6329876B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a television image photographing apparatus, and more particularly to a television image photographing apparatus for photographing medical television images.

Medical television images have traditionally been photographed for diagnostic purposes, but with conventional television image photographing devices, the image projected on a cathode ray tube is, for example, 1/30 according to the NTSC system.
The image is shot at a shutter speed of less than a second and is one frame or more long. However, since there is an error in the shutter speed, exposure unevenness occurs when the shutter speed is close to 1/30 second.
To eliminate this uneven exposure, you can slow down the shutter speed, but if you slow down the shutter speed, moving images will appear blurry and you will not be able to obtain sharp photos. Particularly, when television images are taken with an endoscopic camera, since the endoscopic camera has a mirror shutter, the shutter is open for a long time, and sharp pictures cannot be obtained due to the above-mentioned blur.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a television image photographing apparatus that can obtain good photographs without being greatly affected by shutter speed.

According to the present invention, there is provided a television image photographing device that projects at least two fields of video on a display device based on the relationship between a signal at the start of shutter opening of a camera and a vertical synchronization signal, and photographs the video.

Embodiments of the present invention will be described below with reference to the drawings.

According to FIG. 1, a solid-state image pickup device 14 is disposed at a distal end portion 12 of an endoscope 11, facing an objective lens 13. This solid-state image sensor 14 is connected to a signal processing unit 15 via a signal line 14a. A monitor television 16 is attached to this signal processing unit 15.
A camera 17 is attached to 6. The endoscope 11 is provided with a light guide fiber 18, and this light guide fiber 18 is connected to a universal cord 19.
It extends to the connector 19a through the inside. Connector 19a is connected to light source device 20.

The monitor television 16 is provided with an amplifier 21 for amplifying the video signal from the signal processing unit 15, as shown in FIG. Connected. In addition, an analog switch 25 and a resistor 2 are connected to the output terminal of the amplifier 21.
6 to the cathode ray tube 24 and to the synchronization separation circuit 27. Synchronous separation circuit 27
The output terminal of is connected to a vertical deflection circuit 29 via a vertical separation circuit 28 and to a horizontal deflection circuit 32 via a horizontal separation circuit 31. Vertical and horizontal deflection circuits 29 and 32 are connected to deflection coil 30. The output end of the horizontal deflection circuit 32 is connected to a high voltage rectifier circuit 33, and the output end of this high voltage rectifier circuit 33 is connected to the anode terminal of the cathode ray tube 24. The output terminal of the vertical separation circuit 28 is connected to a frequency dividing circuit 35 via a flip-flop 34. The output terminal of the frequency dividing circuit 35 is connected to the first input terminal of the NAND gate 36. A second input terminal of the NAND gate 36 is connected to a monostable multivibrator 38, and an output terminal is connected to a control input terminal of the analog switch 25 via an inverter 37.

A power source 43 for the camera 17 is connected to an input terminal of a differentiating circuit 41 and an inverter 44 via a shutter switch 42. The output terminal of the differentiator circuit 41 is connected to a monostable multivibrator 38 and a flip-flop circuit 34 via a rectifier circuit 40 and a waveform shaping circuit 39. The output end of the inverter 44 is connected to the control input end of the analog switch 22 via a connector 45. monitor television 16
A lens 46, a mirror 47, and a film 48 are sequentially arranged facing the cathode ray tube 24.

Next, the operation of the television image photographing apparatus having the above configuration will be explained. When the insertion section of the endoscope 11 shown in FIG. The image is formed on the element 14. The solid-state image sensor 14 sends a video signal corresponding to the image inside the body cavity through a signal line 14a.
The signal is supplied to the signal processing unit 15 via. The output video signal of the signal processing unit 15 is amplified by an amplifier 21 of the monitor television 16, and the amplifier 21 outputs a video signal A shown in FIG. At this time, when the release button of the camera 17 is pressed and the shutter starts to open, the switch 42
is closed, and signal B is input to the differential circuit 41 and inverter 44. This signal B is transmitted to the inverter 44
The signal C is inverted by the signal C and supplied to the control input terminal of the analog switch 22. The analog switch 22 detects the rising edge c of signal B, that is, the falling edge of signal C.
It is opened at c' to stop inputting the video signal A to the cathode ray tube 24. That is, analog switch 2
The video signal via 2 becomes as shown in D. On the other hand, the video signal A is synchronously separated by a sync separation circuit 27, and the sync separation signal from this sync separation circuit 27 is separated into vertical and horizontal synchronous signals by vertical and horizontal separation circuits 28 and 31, and the vertical and horizontal polarization signals are separated. Supplied to circuits 29 and 32. The deflection signals of vertical and horizontal deflection circuits 29 and 32 are supplied to a deflection coil 30. Vertical synchronization signal E is flip-flop 3
4 is input. The control input terminal of this flip-flop 34 includes a rectifier circuit 40 and a waveform shaping circuit 3.
A signal F from a differentiating circuit 41 via a differential circuit 9 is supplied. This signal F is generated when the shutter starts to open, and this signal F
4, the flip-flop 34 generates an output signal G in synchronization with the vertical synchronization signal after the generation of this signal F. The frequency of this signal G is divided by, for example, 1/2 by the frequency dividing circuit 35. The output signal H of the frequency dividing circuit 35 is supplied to the first input terminal of the NAND gate 36. Since the output signal J of the monostable multivibrator 38 triggered by the signal F is input to the second input terminal of this NAND gate 36, the signal H and the signal J are inputted from this NAND gate 36.
A NAND output signal is output. Note that the pulse width T ₀ of the signal J is at least 1 frame, that is, 2
The time is set to cover the video signal for the field (2V), for example, longer than 1/30 seconds and shorter than 1/15 seconds. The output signal of the NAND gate 36 is inverted by an inverter 37 and supplied as a signal K to the control input of the analog switch 25. This signal K has a pulse width of 2 volts for 2 fields, so the analog switch 25 is closed for the duration of 2 fields. Therefore, the video signal L for two fields is transmitted through the analog switch 25.
is supplied to the cathode ray tube 24, and images for two fields are projected on the cathode ray tube 24. At this time, since the mirror 47 is up and the shutter is open, the image on the cathode ray tube 24 is projected onto the film via the lens 46. After the video signal L for two fields is supplied to the cathode ray tube 24, the analog switch 25 is opened again and the image on the cathode ray tube 24 disappears. Thereafter, when the shutter is closed and the shutter switch 42 is opened, the analog switch 22 is closed in response to the falling edge d of the signal B, and the video signal A is supplied to the cathode ray tube 24 via the analog switch 22. That is, the signal M is supplied to the cathode ray tube 24, and after images for two fields are displayed on the cathode ray tube 24 for photographing, normal images are continuously displayed. That is, analog switches 22 and 25
The video display is stopped when both of the analog switches 22 and 25 are opened, and the video display is restarted when either one of the analog switches 22 and 25 is closed.

As explained above, according to the present invention, a vertical synchronization signal is detected after the shutter starts opening, and video signals for at least two fields are supplied to the cathode ray tube in synchronization with this vertical synchronization signal, and the video signals for two fields are supplied to the cathode ray tube. is projected onto a cathode ray tube, and the images of these two fields are imprinted onto film. Therefore, even if the shutter speed is slow, only two fields' worth of images are recorded on the film, so that a high-quality photograph with no blurring can be obtained.

In addition, in the above embodiment, for two fields, that is,
The explanation has been made assuming that one frame's worth of images is taken, but if it is desired to take two frames' worth of images, the frequency dividing circuit may be divided into 1/4. In addition, since a frequency dividing circuit is used in the embodiment, images for frames 1, 2, 4, 8, etc. are taken, but if a counter is used to count the vertical synchronization signal, 1, 2, 3, 4, 5 images are taken.
It becomes possible to shoot for frames or to shoot in units of fields.

Further, although a solid-state imaging device is used as the imaging device, the present invention is not limited to this, and an ordinary television camera may be attached to the eyepiece of the endoscope and the video signal from this television camera may be used. Furthermore,
It can be applied not only to endoscopes but also to ordinary medical television systems. According to the above-mentioned invention, since the observation image and the photographed image are outputted by one television, the configuration is quite simple, and there is no need for a complicated mechanism for synchronizing the shutter with respect to continuous images. Furthermore, since the shutter is blocked out for a period longer than the time required to open and close the camera, several frames are taken after the shutter opens, and then the shutter is blocked again and the shutter is closed, there is no need for fine timing adjustments when shooting. Malfunctions due to timing are eliminated.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an endoscope system using a television image photographing device according to an embodiment of the present invention, FIG. 2 is a circuit diagram of the television image photographing device, and FIG. FIG. 2 is a time chart for explaining the operation of the circuit shown in FIG. 2; DESCRIPTION OF SYMBOLS 11... Endoscope, 14... Solid-state image sensor, 15... Signal processing unit, 16... Monitor television, 1
7... Camera, 20... Light source device, 22, 25... Analog switch, 27... Synchronization separation circuit, 28... Vertical separation circuit, 29... Vertical deflection circuit, 30... Deflection coil, 31... Horizontal separation circuit, 32... Horizontal deflection circuit ,
33...High voltage rectifier circuit, 34...Flip-flop,
35... Frequency divider circuit, 38... Monostable multivibrator, 39... Waveform shaping circuit, 40... Rectifier circuit, 41
... Differential circuit, 43... Power supply.

Claims (1)

[Scope of Claims] 1. Switch means connected between the video signal generation means and the video display means, a first detection means for detecting the start point of shutter release, and a first detection means responsive to the detection signal of the first detection means. means for opening the switch means to stop video display; second detection means for detecting a vertical synchronization signal after the start of shutter release; and sending video signals corresponding to a predetermined number of fields to the video display means. means for closing the switch means for a time corresponding to the predetermined number of fields in response to the vertical synchronization signal, and switching the switch means to the open side after closing the switch means for a time corresponding to the predetermined number of fields; A television comprising: means for closing the switch means after closing the shutter and restarting video display; and means for photographing a video image corresponding to the predetermined number of fields of video signals displayed on the video display means. Jiyoung image photography device. 2. The television image photographing apparatus according to claim 1, wherein the predetermined number of fields is an integral multiple of 2 fields. 3. The video signal generating means comprises a solid-state image sensor that captures an image of the inside of a body cavity using an endoscope, and a signal processing circuit that processes signals from the solid-state image sensor. The television image photographing device described above.