JPH04180366A - Television image pickup device - Google Patents

Abstract

PURPOSE:To easily operate a shading correction circuit by detecting and judging the on-time of a trigger switch which operates a black level balance circuit or a white level control circuit which automatically adjust a black level or a white level. CONSTITUTION:At the shading correction circuit 13, a microcomputer 12 detects the signal level in a shading state of each channel from a signal processing part 9 by a certain trigger instruction, and writes an appropriate correction waveform on programmable memory 14. The content of written memory 14 is read out by an address generation circuit 15 which drives the memory, and an appropriate shading correction waveform can be obtained. The on-time of the trigger switch 10 is time-detected by the microcomputer 12, and the black level balance circuit 7 is operated when the on-time shows an arbitrary constant time, for example, the one less than five seconds, and the shading correction circuit 13 is operated when it shows the on-time exceeding five seconds.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention provides an image pickup tube or an all-in-one image pickup system with improved operability especially when performing shading correction of the black level or white level of a captured television video signal waveform. The present invention relates to an imaging device using a child.

BACKGROUND OF THE INVENTION In recent years, the performance and automatic adjustment of color television imaging devices have improved. In particular, in order to improve the quality of images captured by color television cameras, there is a need for automated technology for shading correction of black level or white level.

A shading correction technique conventionally used in this type of imaging device will be explained using black level correction of a solid-state imaging device (hereinafter referred to as a COD camera) as an example.

In FIG. 2, the light image from the subject is captured by the imaging lens, 16
The light is collected by the CCD 17, converted into a video signal by the CCD 17, and outputted through the preamplifier section 1B and the signal processing section 19.

In a COD camera having the above configuration, shading near the black level as shown in FIG. 3 tends to occur even when input light is blocked due to the dark current of the COD itself and uneven charge transfer. Furthermore, the dark current generally increases by about twice as much as the ambient temperature rises by 10'C.
Therefore, the shading caused by the dark current also increases approximately twice.

The shading correction circuit in a conventional COD camera includes a horizontal triangular wave generating circuit 20, a vertical triangular wave generating circuit 21, a horizontal parabolic wave generating circuit 22, and a vertical parabolic wave generating circuit 23, as shown in FIG. The gain of each signal is adjusted and added.

The resulting shading correction signal with the waveform shown in FIG. 4 is added to the output signal from the CCD 17, so that even if the input signal is cut off, the black level signal will be as shown in FIG. 6. Corrected to create a flat signal with no shading.

Problems to be Solved by the Invention As described above, gain adjustment at four locations (24, 25, 26, 27) is required for one C0D17.
If it is a board-type color television camera, the adjustment is 1.
Needless to say, it is complicated and difficult as it involves two locations. Furthermore, although the shading correction circuit described above is effective for a specific shading waveform, COD
If the camera is used for a long time, the ambient temperature of the COD may rise due to heat generation, or the shading waveform may increase as mentioned above, so it takes a lot of effort to adjust the shading correction circuit each time. I needed it.

In recent years, due to digitalization of signal processing, some circuits are able to automatically perform shading correction, but they must also be corrected again in response to changes in ambient temperature, requiring complicated adjustment methods. There are other problems.

To solve the above problem, it would be possible to install a new trigger switch on the camera to start shading correction, but this would require an additional switch in the camera switch operation mechanism, and it would be necessary to prevent malfunctions. Therefore, the mechanism becomes complicated and costs increase.

The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a color television imaging device that can easily start the blank kneading correction without changing the conventional camera switch operation section.

Means for Solving the Problems In order to achieve the above object, the present invention provides any means constituted by a microcomputer having means capable of detecting a signal level, a readable memory, and an address generation circuit for driving the memory. a shading correction circuit that automatically operates according to the microcomputer, and a black level balance circuit or a white level control circuit that automatically adjusts the black level or the white level, and the black level balance circuit or the white level control circuit. The trigger switch for operating the shading correction circuit is also used as a switch for automatically operating the shading correction circuit.The present invention provides a black level balance circuit or a black level balance circuit for automatically adjusting the black level or the white level. O of the trigger switch that operates the white level control circuit
By detecting and determining the N time, the shading correction circuit can be easily operated without changing the switch operation mechanism of a conventional color television camera.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to FIG.

As shown in FIG. 1, the light focused by the imaging lens 1 passes through the prism group 5, is received by the ccn section 2.degree. 3.4, and is photoelectrically converted. Here, COD2.3.4 is a solid-state imaging device that separately captures images of three primary colors, for example, red, blue, and green. The output signal from COD2.3.4 is
The signal is supplied to the preamplifier section 6, unnecessary noise components are removed, and the signal is amplified to an arbitrary amplitude. The output signal of the preamplifier section 6 is added to the correction signal from the shading correction circuit 13 to form a waveform without shading, which is then sent to the black level balance circuit 7 and subjected to the shading correction of the white level after t-, and then sent to the white level control circuit 8. The signal is then supplied to the signal processing section 9. The signal processing unit 9 performs various signal processing, and the output signal of the signal processing unit 9 is output as a standard video signal (television camera output signal).

In the shading correction circuit 13, the signal processing section 9 and the microcomputer 12 detect the signal level of the shading state of each channel in response to a certain trigger command, and store an appropriate correction waveform in the read/write memory 14. The written contents of the memory 14 are read out by the address generation circuit 16 that drives this memory so that an appropriate shading correction waveform can be obtained.

Also, the black level balance circuit trigger switch 1o is set to O.
When the ON state is determined by the microcomputer 12, the black level balance circuit 7 is operated by the microcomputer 12. The black level balance circuit 7 is a circuit in which the signal level detected by the signal processing section 9 is detected by the microcomputer 12, and is controlled by the microcomputer 12 so that the black level of each channel is the same. The trigger switch 10 of this black level balance circuit 7 is generally called a 5BB (auto black balance) switch in a three-tube or three-panel color television camera.
It is widely adopted.

The ON time of this trigger switch 1o is detected by the microcomputer 12, and the ON time of the trigger switch 1o is detected by the microcomputer 12, and
If it is N time, operate the black level balance circuit 7,
If the ON time is longer than seconds, the shading correction circuit 13
K to make it work.

As mentioned above, by using the operation trigger switch 1o of the black level balance circuit and the operation trigger switch of the shape ink correction circuit, the switch operation mechanism of the color television camera can be easily realized without changing the conventional configuration. . Furthermore, for color television camera users, since the same black level is corrected, it is easy to recognize, and by lengthening the ON time of the switch, malfunctions can be prevented, which is extremely effective.

In this example, a microcomputer is used for time detection, but
The same objective can be achieved even if a new time detection circuit is provided. Although it also serves as the trigger switch 1o of the black level balance circuit, the white level control circuit trigger switch 11 is also used when correcting white level shading caused by chromatic aberration of the lens. It is clear that it is also effective to use a switch called an auto white control switch for the same purpose.

When the white level control circuit is used here, it operates in the same way as the black level balance circuit, so a specific explanation will be omitted.

Effects of the Invention As described above, according to the present invention, there is provided a color television imaging device in which the shading correction circuit can be easily operated without changing the operation mechanism of the camera switch, and malfunctions can also be prevented. can be provided.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing the configuration of a COD color television camera according to an embodiment of the present invention, and FIG. 2 is a circuit diagram showing the configuration of a COD color television camera according to an embodiment of the present invention.
A circuit diagram showing the configuration of a camera shading correction circuit,
FIG. 3 is a waveform diagram of a video signal with black level shading, FIG. 4 is a waveform diagram of a correction signal generated by the shading correction circuit, and FIG. 6 is a waveform diagram of a corrected video signal. 7... Black level balance circuit, 8...
White level control circuit, 10... Black level balance circuit trigger switch, 11... White level control circuit trigger switch, 12...
...Microcomputer, 13...Shading correction circuit, 14...Readable memory, 16...
...Address generation circuit. <2=> Ward C'J

Claims (2)

[Claims] (1) A shading correction circuit made up of a microcomputer with means for detecting the video signal level, a readable/writable memory, and an address generation circuit that drives the memory, and a black color made up of the microcomputer and a circuit that adjusts the black level. 1. A television imaging device having a level balance circuit, wherein a trigger switch for operating the black level balance circuit also serves as a switch for operating the shading correction circuit. (2) A shading correction circuit made up of a microcomputer with means for detecting the video signal level, a read/write memory, and an address generation circuit that drives the memory, and a white color made up of the microcomputer and a circuit that adjusts the white level. a level control circuit, and a trigger switch for operating the white level control circuit also serves as a switch for operating the shading correction circuit.