JPH0514935A - Level display device for video signal - Google Patents

Abstract

PURPOSE:To easily control contrast and brightness by devising the level display of a video signal. CONSTITUTION:The signals outputted from the peak detecting circuit 5 at a white side and the peak detecting circuit 7 at the black side of the video signal are respectively inputted to a microcomputer 9 with A/D converter 6 and 8. A specified graphic and character, the RBG signal of a character generator 19 and the three sets of primary color signals at a TV side are changed-over by driving a changeover switch 11. The black level and white level of the video signal are bar-displayed in CRT 12 and a corresponding measure is given. When contrast is controlled by a remote controller, the measure corresponding to controlled variable is displayed and display is executed in accordance with the measure corresponding to bar display.

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 optimum contrast and brightness of a color television set.

[0002]

2. Description of the Related Art In recent years, with the increase in size of color television sets, the added value has been increased and the contrast control and the brightness control have been devised.

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

The operation of the video signal signal processing circuit configured as described above will be described below. The color signal reproduction circuit 1 reproduces and outputs only the color signal from the input composite video signal, and the signals output from the contrast control unit 2 and the brightness control unit 3 from the composite video signal are generated by the color signal reproduction circuit 1. The output signal is added by the adder 4, and a video signal is displayed on the CRT 12.

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

[0006]

However, in the above configuration, the optimum contrast and brightness positions cannot be found because the contrast and brightness are controlled only by looking at the television signal on the screen.

In view of the above problems, the present invention provides a video signal level display device which knows the video signal level and facilitates control of contrast and brightness.

[0008]

In order to achieve this object, a video signal level display apparatus of the present invention extracts a color subcarrier from a composite video signal and reproduces the color signal from the color subcarrier. A reproduction circuit, a contrast control unit for inputting a luminance signal and controlling the contrast of the luminance signal,
A brightness control unit that controls the brightness of the brightness signal, a white-side detection circuit that detects a white-side peak of a video signal, and a first A / D conversion that converts the output of the white-side detection circuit into a digital signal. , A black side detection circuit for detecting a black side peak of a video signal, a second A / D converter for converting an 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 figures 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 are switched. It consists of switches.

[0009]

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

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 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 designated 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 detection circuit for detecting the white peak of the video signal, 6 is an A / D converter, 7 is a black detection circuit for detecting the black peak of the video signal, and 8 is A.
A / D converter, 9 is a microcomputer that outputs a control signal to the contrast control unit 2 and the brightness control unit 3 and the like based on the information obtained from the A / D converters 6 and 8.
Reference numeral 10 is a character generator for displaying a specific figure, character or the like on the CRT under the control of the microcomputer, and 11 is 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 having the above configuration will be described below. The signals output from the white-side detection circuit 5 that detects the white-side peak of the video signal and the black-side detection circuit 6 that detects the black-side peak of the video signal are digitalized by the A / D converters 6 and 8, respectively. After conversion, it is input to the microcomputer 9. By the control of the microcomputer,
The input signal can be switched by the switch 11 that switches between the RGB signal of the character generator 10 for displaying a specific figure and characters on the CRT and the three sets of primary color signals on the television side. Therefore, it is possible to display the black side level and the white side level of the video signal in a bar on the CRT and to insert a scale corresponding to the bar display. Further, in the video signal level display device, when a contrast or the like is controlled by a remote controller or the like, a scale corresponding to the control amount is displayed, and the black side and the white side of the video signal are bar-displayed on the CRT. It can be displayed according to the scale corresponding to the display.

As described above, according to the present embodiment, the black level and the white level of the video signal are bar-displayed on the CRT so that the level of the video signal can be known and the contrast and brightness can be easily controlled. be able to.

[0013]

As described above, according to the present invention, it is possible to easily control the contrast and the brightness by devising the level display of the video signal, and the practical effect is great.

[Brief description of 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]

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)

[Claims] 1. 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 inputs 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 a 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 the black side peak of the video signal, and a first for converting the output of the black side detection circuit to digital. Two A / D converters, a microcomputer that receives the outputs of the first and second A / D converters and outputs a control signal, etc., and a specific figure, character, etc. by the control of the microcomputer.
Character generator displayed on T and 3 on 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 the black side level and the white side level of the video signal on a CRT. . 2. A black level and a white level of a video signal are bar-displayed on a CRT in a video signal level display device,
2. The video signal level display device according to claim 1, further comprising a scale corresponding to the bar display. 3. A video signal level display device displays a scale according to a control amount when controlling contrast or the like with a remote controller or the like, and the black side level and the white side level of the video signal according to claim 2. Is displayed on the CRT as a bar, and a scale corresponding to the bar display is also displayed together.