JPS62292082A - White uniformity adjusting circuit for color television receiver - Google Patents

Abstract

PURPOSE:To easily adjust white uniformity by providing the titled circuit with a means for selecting an optional position on a screen and a means for shaping the waveform of an output generated from said selecting means. CONSTITUTION:A selecting section output circuit 9 is adjusted to generate a selecting section output corresponding to a white uniformity adjusting part 14. The output is added to a waveform shaping circuit 10 to obtain a white uniformity corrected waveform. When the quantity of light from a red phospher is small in the adjusting part 14, red is selected by a switch circuit 11 and the red signal is added to an output signal from a main contrast adjusting circuit 12 with optional size by an adder circuit 13. A contrast driving circuit 5 is driven by an output signal from the adder 13. Consequently, white uniformity can be easily adjusted.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] This invention relates to a white uniformity adjustment circuit for a color television receiver.

[Conventional technology]

Conventionally, in color television receivers, white uniformity has often been impaired due to processing precision of shadow masks or manufacturing variations in electron guns and deflection yokes. Installation involved adjusting the position, adjusting the color purity magnet, and gluing the magnet to the cathode ray tube.

However, as the definition of cathode ray tubes increases, the dot diameter of the shadow mask or the beam diameter becomes smaller, and the white
Uniformity adjustment has become difficult to achieve using only the above-mentioned means, and the demand for white uniformity adjustment for high-definition cathode ray tubes has also become high.

Therefore, conventionally, a white uniformity adjustment circuit as shown in FIG. 5, for example, has been devised. In FIG. 5, 1 is the horizontal synchronization signal HD.

A control signal generation circuit which takes the vertical synchronization signal VD as input and generates control signals etc. to divide the screen into appropriate parts. 2 is a control signal generation circuit which arbitrarily specifies the divided part by the control signal generation circuit 1 and inputs arbitrary data. 3 is a memory circuit that is controlled by the control signal generated by the control signal generation circuit 1 and stores and outputs the data input by the data input circuit 2; 4 is a memory circuit that stores and outputs the digital data output from the memory circuit 3; 5 is a contrast drive circuit that changes the amplitude of the video signal by the output of the digital-to-analog converter circuit 4; 6 is a video circuit; and 7 is a white circuit composed of the above circuits 1 to 5.・Uniformity adjustment circuit.

For example, as shown in FIG. 6, a television receiver is provided with three white uniformity adjustment circuits, 7R17G and 7B, for red, green, and blue, and video output circuits 6R and 7B, respectively, as shown in FIG. After passing through 6G and 6B, it is input to a display 8 such as a cathode ray tube.

In the white uniformity adjustment circuit configured as described above, for example, the adjuster observes the display 8 that has received the white signal, and controls any part of the screen divided by the signal generation circuit 1 to the data input circuit 2. Select. Now, if the light of the red phosphor is weak in a certain part, the memory circuit 3 of the red/white uniformity adjustment circuit 7R is programmed to increase the red contrast, that is, increase the beam amount of the red electron gun. The amount of data is adjusted and a signal is manually input from the data input circuit 2.

White uniformity can be adjusted by performing this adjustment on any part of the screen for red, green, and blue.

[Problem that the invention seeks to solve]

The conventional device has the above-mentioned structure, and has problems such as being expensive and having a large circuit scale because it includes a memory circuit and an arithmetic circuit using an IC.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a circuit that can adjust white uniformity easily and inexpensively with an hour wheel circuit configuration.

[Means for solving problems]

The white uniformity adjustment circuit according to the present invention includes a selected section output circuit that selects and outputs an arbitrary location on the screen, and a waveform shaper that waveforms the output of this circuit to obtain a white uniformity adjustment signal. and an addition circuit for adding the white uniformity adjustment signal and the main contrast adjustment signal.

[Effect]

White uniformity according to this invention 1ll
Since the rectifier circuit has the above configuration, white uniformity can be easily adjusted.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, 9 is a horizontal synchronizing signal HD, a vertical synchronizing signal VD
A selection section output circuit which selects an arbitrary part on the screen using as input, and outputs a signal corresponding to the selected part;
0 is a waveform shaping circuit that shapes the output of the selected section output circuit 9 into an arbitrary shape such as a parabolic signal, and 11 is a waveform shaping circuit 10.
A switch circuit 12 switches the supply of the output to red (R), green (G), and blue (B) circuits, a main contrast adjustment circuit 12 adjusts the contrast across the entire spectrum, and a switch circuit 13 passes through the switch circuit 11. 5 is a contrast drive circuit that changes the amplitude of the video signal according to the output of the adder circuit 13; is the video circuit, 7 is the above circuit 9
10.11 is a white uniformity adjustment circuit.

Further, in the circuit of this embodiment, as shown in FIG. 2, the white uniformity adjustment circuit is
．． ...7n (!R), and each red (R
), green (G), blue (B) adder circuits 13R, 13G, 1
3B, contrast drive circuits 5R, 5G, 5B, and video output circuits 6R, 6G, 6B, and then manually inputted to a display 8 such as a cathode ray tube.

Next, for example, white uniformity adjustment part 1
A method of adjusting white uniformity in a case where the deviation of white uniformity is largest near the center of 4 and becomes smaller toward the periphery will be described.

The adjuster looks at the display screen that receives the white signal (Figure 3).
Observe the system wide uniformity adjustment part 14
Regarding this, adjustments will be made as shown in Figure 4 below.

That is, first, the selection section output circuit 9 is adjusted, and the white
A selected section output 15 corresponding to the uniformity adjustment portion 14 is output, and this is waveform-shaped by a waveform shaping circuit 10 to obtain, for example, a parabolic white uniformity correction waveform 16.

And the above white uniformity adjustment part 14
If the amount of light from the red (R) phosphor is small in By driving the contrast drive circuit 5 with the output signal, a red (R) video output signal 17 is obtained, and good white uniformity is obtained over the entire screen.

In this embodiment, the correction waveform is a parabolic waveform as shown in 16 of FIG. 4, but it may be any waveform such as a triangular wave or a rectangular wave, depending on the characteristics of the display used. By doing so, good effects can be obtained.

〔Effect of the invention〕

As described above, according to the white uniformity adjustment circuit for a color television receiver according to the present invention,
Since the white uniformity adjustment circuit has the above-described circuit configuration, the circuit can be constructed easily and inexpensively, and has the effect of providing a highly accurate circuit.

[Brief explanation of drawings]

FIG. 1 is an internal configuration diagram of a white uniformity adjustment circuit according to an embodiment of the present invention, FIG. 2 is a configuration diagram of the white uniformity adjustment circuit of FIG. 1 incorporated into a display device, and FIG. - A diagram showing the display screen during uniformity adjustment, Figure 4 is a diagram showing each circuit waveform during white uniformity adjustment, Figure 5 is an internal configuration diagram of a conventional white uniformity adjustment circuit, and Figure 6 5 is a configuration diagram of the white uniformity adjustment circuit of FIG. 5 incorporated into a display device. FIG. 5 is a contrast drive circuit, 5R, 5G. 5B are red, green, and blue contrast drive circuits, respectively.
6 is a video output circuit, 6R, 60, 6B are each red,
Green, blue video output circuits, 7,71°~7n are white.
Uniformity adjustment circuit, 7R, 7G, 7B are red, green, blue and white uniformity adjustment circuits respectively, 8 is display, 9 is selected section output circuit, 10 is waveform shaping circuit, 11 is switch circuit, 12 is main contrast Adjustment circuits 12R, 12G, and 12B are red and green, respectively. Caterpillar contrast circuit, 13 is addition circuit, 13R213
0 and 13B are red, green, and blue addition circuits, 14 is a white uniformity adjustment section, 15 is a selected section output, 16 is a white uniformity correction waveform, 1
7 is a video output signal. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] (1) In the white uniformity adjustment circuit of a color television receiver, there is a selected section output circuit that generates a signal corresponding to an arbitrarily selected part of the screen, and a white uniformity adjustment that shapes the waveform of the output signal. A waveform shaping circuit that generates a signal, an adder circuit that adds the main contrast adjustment signal and the white uniformity adjustment signal, and a contrast drive circuit and video that adjust the contrast of the video signal using the adder signal output from the adder circuit. A white uniformity adjustment circuit comprising a video output circuit that outputs a signal.