JP3106560B2 - Video signal level display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal level display device capable of easily setting an optimum contrast and brightness of a color television set.

[0002]

2. Description of the Related Art In recent years, as color television sets have become larger, higher added value has been developed and contrast control and brightness control have been devised.

FIG. 2 is a schematic block diagram from a conventional composite video signal to displaying an image on an RCT. In the figure, reference numeral 1 denotes a color signal reproducing circuit for reproducing a color signal from a composite video signal. Reference numeral 2 denotes a contrast control unit that controls the gain of the video signal, that is, the contrast. Reference numeral 3 denotes a brightness control unit that controls the DC level of the video signal. Reference numeral 4 denotes an adder for adding the output of the color signal reproduction circuit 1 to the signal output by the contrast control and the brightness control. Reference numeral 12 denotes a CRT for outputting an image or the like.

The operation of the signal processing circuit for a video signal configured as described above will be described below. Only a color signal is reproduced and output from the input composite video signal by the color signal reproduction circuit 1, and a signal output from the composite video signal by the contrast control unit 2 and the brightness control unit 3 is output from the color signal reproduction circuit 1. The output signal is added to the output signal by the adder 4 to output a video signal on the CRT 12.

Therefore, in the conventional circuit, when the contrast and brightness are controlled by a remote controller or the like, the control is performed while watching only the television signal on the screen.

[0006]

However, in the above-described configuration, since the contrast and brightness are controlled only by watching the television signal on the screen, the optimum position of the contrast and brightness cannot be determined.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and provides a video signal level display device which knows the level of a video signal and facilitates control of contrast and brightness.

[0008]

To achieve this object, a video signal level display device according to the present invention extracts a color subcarrier from a composite video signal and reproduces a color signal from the color subcarrier. A reproduction circuit, a contrast control unit that receives a luminance signal and controls the contrast of the luminance signal,
A brightness control unit for controlling the brightness of the luminance signal, a white-side detection circuit for detecting a white-side peak of the video signal, and a first A / D converter for converting the output of the white-side detection circuit to digital A black-side detection circuit for detecting a black-side peak of the video signal; a second A / D converter for converting the output of the black-side detection circuit into a digital signal; and the first and second A / D converters. A microcomputer that receives the output of the D converter, a character generator that displays specific graphics and characters on a CRT under the control of the microcomputer, and three sets of primary color signals on the television side and RGB signals of the character generator. Consists of switches.

[0009]

With this configuration, it is possible to display information on the black-side level and the white-side level of the video signal on a CRT. Then, the black side level and the white side level of the video signal are CR
A bar is displayed on T, and a scale corresponding to the bar display can be inserted. Further, in the video signal level display device, when controlling the contrast or the like with a remote controller or the like, a scale corresponding to the control amount is displayed, and the black side level and the white side level of the video signal are displayed as bars on a CRT. The scale corresponding to the display can be displayed together.

[0010]

An embodiment of the present invention will be described below with reference to the drawings. The same functions as those in the conventional example are denoted by the same reference numerals as those in FIG. FIG. 1 is a schematic block diagram of a video signal level display device according to an embodiment of the present invention. In the figure, 5 is a black side detection circuit for detecting a white side peak of a video signal, 6 is an A / D converter, 7 is a black side detection circuit for detecting a black side peak of a video signal, and 8 is A
A microcomputer 9 for outputting a control signal to the contrast control unit 2 and the brightness control unit 3 based on the information obtained from the A / D converters 6 and 8;
Reference numeral 10 denotes a character generator for displaying specific graphics and characters on a CRT under the control of the microcomputer. Reference numeral 11 denotes a switch for switching between three sets of primary color signals on the television side and RGB signals of the character generator.

The operation of the video signal level display device configured as described above will be described below. The signals output by the white-side detection circuit 5 for detecting the white-side peak of the video signal and the black-side detection circuit 6 for detecting the black-side peak of the video signal are converted into digital signals by A / D converters 6 and 8, respectively. After the conversion, it is input to the microcomputer 9. By the control of the microcomputer,
An input signal can be switched by a switch 11 that switches between an RGB signal of a character generator 10 for displaying a specific graphic, a character, or the like on a CRT and three sets of primary color signals on the television side. Therefore, the black side level and the white side level of the video signal can be displayed as bars on the CRT, and graduations corresponding to the bar display can be provided. Further, in the video signal level display device, when controlling the contrast or the like with a remote controller or the like, a scale corresponding to the control amount is displayed, and the black side level and the white side level of the video signal are displayed as bars on a CRT. It can be displayed according to the scale corresponding to the display.

As described above, according to the present embodiment, the black side level and the white side level of the video signal are displayed as bars on the CRT, so that the level of the video signal is known and the control of contrast and brightness is facilitated. be able to.

[0013]

As described above, according to the present invention, the control of the contrast and brightness can be facilitated by devising the level display of the video signal, and the practical effect is large.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of a video signal level display device according to an embodiment of the present invention.

FIG. 2 is a schematic block diagram of a conventional example.

FIG. 3 is a bar display diagram of a black level and a white level of a video signal on a CRT.

FIG. 4 is a bar display diagram showing a scale corresponding to the bar display.

[Explanation of symbols]

 Reference Signs List 5 White-side detection circuit 6 A / D converter 7 Black-side detection circuit 8 A / D converter 9 Microcomputer 10 Character generator 11 Switch

Claims (3)

(57) [Claims] A color signal reproduction circuit for extracting a color subcarrier from a composite video signal and reproducing a color signal from the color subcarrier;
A contrast control circuit that receives a luminance signal and controls the contrast of the luminance signal, a brightness control circuit that controls the brightness of the luminance signal, a white-side detection circuit that detects a white-side peak of the video signal, A first A / D converter for converting the output of the white-side detection circuit into a digital signal, a black-side detection circuit for detecting a black-side peak of the video signal, and a second A / D converter for converting the output of the black-side detection circuit into a digital signal. Two A / D converters, a microcomputer that receives the outputs of the first and second A / D converters and outputs a control signal and the like, and converts a specific figure, character, or the like under the control of the microcomputer.
Character generator displayed on T and 3 on the TV side
A video signal level display device comprising a switch for switching between a set of primary color signals and the RGB signal of the character generator, and displaying information on a black level and a white level of the video signal on a CRT. . 2. A video signal level display device displays a black side level and a white side level of a video signal on a CRT as bars.
2. A video signal level display device according to claim 1, wherein a scale corresponding to the bar display is set. 3. A black level and a white level of a video signal according to claim 2, wherein a scale according to a control amount is displayed when controlling a contrast or the like by a remote controller or the like. 2. The level display device for video signals according to claim 1, wherein a bar is displayed on a CRT and a scale corresponding to the bar is displayed.