JPH0575899A - Controur compensation circuit - Google Patents

Abstract

PURPOSE:To obtain the sufficient contour compensation amount in each band when input signals in more than two different bands are inputted in a display device with the contour compensation circuit. CONSTITUTION:A video signal inputted from a terminal 11 is inputted to a switch 8 after the amplitude adjustment in amplitude adjustment circuits 6 and 7 by generating a contour compensation waveform using the well-known technology by contour compensation waveform generation circuits 4 and 5 for each band. The band of the synchronizing signal inputted from a terminal 12 by the switch 8 is discriminated by a frequency discriminating circuit 9, selecting the proper contour compensation waveform. Then the contrast is adjusted by a contrast adjustment circuit 2 after adding an input video signal from an adder circuit 10, and amplified by an output circuit 3 to be supplied to the cathode of the CRT.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contour compensation circuit used in various display devices.

[0002]

2. Description of the Related Art FIG. 2 is a block diagram of an image amplification unit of a monochrome display device using a cathode ray tube having a conventional contour compensation circuit. In the figure, reference numeral 1 denotes a contour compensation circuit, which includes a contour compensation waveform generation circuit 13, an amplitude adjustment circuit 14, and an addition circuit 10.

A contrast adjusting circuit 2 adjusts the contrast of the video signal output from the contour compensating circuit 1.
An output circuit 3 is composed of an inverting amplifier and is connected to the cathode of the CRT.

The above is the image amplification section of the monochrome display device.
It is composed of three systems of the image amplification section having the above configuration.

Next, the operation will be described. The video signal input from the terminal 11 is input to the contour compensating circuit 1. At this time, the contour compensating waveform generating circuit 13 creates a contour compensating waveform of this video signal, and the amplitude adjustment is performed by the amplitude adjusting circuit 14.
After that, the addition circuit 10 adds this signal and the video signal input from the terminal 11.

Next, after being input to the contrast adjusting circuit 2 and subjected to contrast adjustment, it is amplified by the output circuit 3 and supplied to the cathode of the CRT.

[0007]

Since the conventional contour compensating circuit is constructed as described above, when contour compensation of a video signal of two or more different frequency bands is performed, the contour of one of the frequency bands is compensated. Although a compensation waveform is generated and shared, this has a problem that a sufficient contour compensation range cannot be obtained for the video signal in the other frequency band and the effect is not so great.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a contour compensation circuit capable of performing sufficient contour compensation for a video signal in each frequency band. To do.

[0009]

A contour compensating circuit according to the present invention is configured to generate respective contour compensating waveforms for video signals having different frequency bands, and to switch automatically according to the frequency band of an input video signal. It was done.

[0010]

In the contour compensating circuit according to the present invention, the contour compensating waveform corresponding to each frequency band is generated and switched according to the input video signal, whereby sufficient contour compensation can be obtained.

[0011]

EXAMPLES Example 1. An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an image amplifying portion of a monochrome display device using a cathode ray tube having a contour compensation circuit according to an embodiment of the present invention.
Since 3 and 10 to 11 have been described in the conventional example, the description thereof will be omitted.

In the contour compensating circuit 1, the system of the broad band contour compensating circuit 4 and the amplitude adjusting circuit 6 and the system of the narrow band contour compensating circuit 5 and the amplitude adjusting circuit 7 are connected in parallel to the switch 8
The synchronizing signal is input from the terminal 12, the frequency band discriminating circuit 9 discriminates the band, and the switch 8 is controlled. Then, the addition circuit adds the video signal input from the terminal 11.

The image amplification section of the monochrome display device has been described above.
The image amplification unit having the above-mentioned configuration is composed of three systems, and the output of the frequency band discrimination circuit 9 is connected to each of the three systems.

Next, the operation of the above configuration will be described.

The video signal input from the terminal 11 is input to the wide band contour compensation waveform generation circuit 4, generates a wide band contour compensation waveform using a well-known technique, and is amplitude-adjusted by the amplitude adjustment circuit 6. Then, it is input to the switch 8. At the same time, the narrow band side is similarly input to the switch 8.

The synchronizing signal is input from the terminal 12,
The frequency band discriminating circuit 9 discriminates between a wide band and a narrow band, and controls the switch 8 according to the band. After that, as in the conventional case, the addition circuit 10 adds the input video signal from the terminal 11, the contrast is adjusted by the contrast adjustment circuit 2, and then the output circuit 3 amplifies and CRs.
It is supplied to the cathode of T.

[0018]

As described above, according to the present invention, since the contour compensation waveform generating circuit is separately configured for each band, there is an effect that a sufficient contour compensation amount can be obtained for all used bands.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an image amplification unit of a monochrome display device using a cathode ray tube including a contour compensation circuit according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of an image amplification unit of a monochrome display device including a conventional contour compensation circuit.

[Explanation of symbols]

 1 Contour compensation circuit 2 Contrast adjustment circuit 3 Output circuit 4 Wideband contour compensation waveform generation circuit 5 Narrowband contour compensation waveform generation circuit 6, 7, 14 Amplitude adjustment circuit 8 Switch 9 Frequency band discrimination circuit 10 Addition circuit 11 Video signal input Terminal 12 Sync signal input terminal 13 Contour compensation waveform generation circuit

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[Procedure amendment]

[Submission date] March 2, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

[0007]

Since INVENTION Problems to be Solved conventional contour compensation circuit is configured as described above, when the contour compensation of two or more different <br/> frequency band of the video signal, either Although the contour compensation waveform of the frequency band is generated and shared, this has a problem that a sufficient contour compensation range cannot be obtained for the video signal of the other frequency band and the effect is not so great.

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

Claims (2)

[Claims] 1. A contour compensation circuit, comprising the same number of contour compensation waveform generation circuits for each band for two or more input video signals. 2. The contour compensating circuit according to claim 1, wherein the frequency band of the synchronizing signal is discriminated, and a contour compensating waveform generating circuit of a required band is automatically selected by means such as a switch. Contour compensation circuit.