JPH06217338A - Automatic hue adjuster - Google Patents

Abstract

(57) [Summary] [Purpose] The purpose is to correct the visual color change of the screen display color due to the color change of the external light incident on the screen display unit to make it easier to see. [Configuration] At least one optical sensor (8 to 10) for detecting a color change of external light incident on a screen display unit and a phase of a subcarrier of a color signal based on an input from the optical sensor. The hue control circuit 6 variably outputs the color demodulation circuit 7 and the color demodulation circuit 7 that performs the color demodulation by using the input from the same hue control circuit 6 and the color signal extracted from the video signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television receiver,
In particular, it relates to an automatic hue adjuster in a demodulation circuit for a color signal in a video signal. In recent years, portable and in-vehicle televisions have become widespread, and they are often used under various conditions.

[0002]

2. Description of the Related Art In a conventional hue adjuster, a hue change due to a variation in a demodulation circuit of a color signal is adjusted to an optimum phase by an operation signal from a remote controller or the like.

[0003]

Therefore, since the color signal is demodulated in a predetermined phase after the adjustment, there is a problem that the screen becomes difficult to see when the color of the external light changes. The present invention corrects a visual color change of a screen display color due to a color change of external light incident on the screen display unit,
The purpose is to make it easier to see.

[0004]

As shown in FIG. 1, at least one optical sensor (8 to 10) for detecting a color change of external light incident on a screen display unit and the optical sensor. And a hue control circuit 6 for varying and outputting the phase of the subcarrier of the color signal based on the input of
And a color demodulation circuit 7 for performing color demodulation using the color signal extracted from the video signal.

[0005]

As described above, according to the present invention, the optical sensor 8 detects red light and outputs a signal, and when the incident light becomes strong, the output level becomes high, as shown in FIG. By inputting it to the hue control circuit 6 having various characteristics and changing the hue to the green side, for example, it is possible to correct that the screen of the television looks red and make it easier to see.

[0006]

FIG. 1 is a block diagram of an electric circuit of an automatic hue adjuster showing an embodiment of the present invention. Reference numerals 8 to 10 denote optical sensors that detect a color change of external light incident on the screen display unit. The optical sensor 8 detects red light and the optical sensor 9 detects blue light. Sensor 1
0 is adapted to detect green light. Optical sensor (8
10 to 10 are, for example, a combination of a solar cell or a phototransistor and a detection filter for each color,
When the incident light becomes strong, the output level is increased and the output of the optical sensor 8 is input to the A / D converter 2.
The output of the optical sensor 9 is input to the A / D converter 3, and the output of the optical sensor 10 is input to the A / D converter 4.

Reference numeral 1 denotes a control unit, which uses, for example, a microcomputer, and A / D converters 2 to 4 convert respective inputs into digital signals so that they can be input to the control unit 1 and input them to the control unit 1. In the microcomputer 1, the inputs are compared and calculated, and a control signal is output and input to the D / A converter 5, and the D / A converter 5
Is converted into an analog signal into a DC voltage, which is input to the hue control circuit 6. The phase of the subcarrier of the color signal generated by the oscillator is synchronized with the burst signal of the input video signal, and the subcarrier is input to one end of the hue control circuit 6. The phase of is changed and output based on the input from the D / A converter 5, and is input to the color demodulation circuit 7. The color demodulation circuit 7 performs color demodulation on the basis of the color signal extracted from the video signal and the input from the hue control circuit 6 and outputs it.

FIG. 2 is an explanatory diagram showing the characteristics of the hue control circuit 6. In the hue control circuit 6, for example, when the input voltage from the D / A converter 5 is high, the phase of the subcarrier is changed so that it becomes a green phase, and when it is low, the phase of the subcarrier is changed so as to become a blue phase. The phase of the subcarrier is changed so that the phase becomes red in the middle, and the subcarrier is input to the color demodulation circuit 7. 3 as the color demodulation circuit 7
Using the axis demodulation circuit, color difference signals (RY), (BY)
And (G-Y) are demodulated and output, and a color signal is displayed on the screen display unit based on the output.

FIG. 3 shows another embodiment of the present invention,
It is an electric circuit block diagram of an automatic hue adjuster. Reference numeral 8 denotes an optical sensor, which detects a change in red light of external light incident on the screen display unit, and when the incident light becomes strong, the output level is increased and the output is input to the synthesis circuit 11. I am trying. Reference numeral 12 denotes a microcomputer, which inputs an operation signal by using an operation unit or a remote controller provided in the device, and the microcomputer 12 outputs a control signal according to the input and outputs D /
The analog signal is input to the A converter 5, converted into an analog signal by the D / A converter 5, and input to the synthesizing circuit 11. The synthesizing circuit 11 synthesizes the DC voltage from the D / A converter 5 and the DC voltage from the optical sensor and inputs the synthesized voltage to the hue control circuit 13.

The hue control circuit 13 changes the phase of the subcarrier of the color signal synchronized with the burst signal of the input video signal on the basis of the input from the synthesizing circuit 11 and outputs it, which is input to the color demodulating circuit 7. ing. In the hue control circuit 13, for example, when the input voltage from the synthesizing circuit 11 is high, the phase of the subcarrier is changed to have a green phase, and when it is low, the phase of the subcarrier is changed to have a blue phase.
A subcarrier is input to the color demodulation circuit 7. Therefore, for example, when the surroundings turn red due to a sunset or the like, the level output from the optical sensor 8 becomes high, and the same output is input to the hue control circuit 13, for example, by changing the hue to the green side, It is possible to correct that the screen looks red and make it easier to see. In the above-described embodiment, the triaxial demodulation circuit is used as the color demodulation circuit 7, but a biaxial demodulation circuit may be used.

[0011]

As described above, according to the present invention,
It is possible to provide an automatic hue adjuster capable of correcting the visual color change of the screen display color due to the color change of the external light incident on the screen display unit to make the image easy to see.

[Brief description of drawings]

FIG. 1 is a block diagram of an electric circuit of an automatic hue adjuster showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing characteristics of a hue control circuit 6.

FIG. 3 is an electric circuit block diagram of an automatic hue adjuster showing another embodiment of the present invention.

[Explanation of symbols]

 1 Control part 2 A / D converter 3 A / D converter 4 A / D converter 5 D / A converter 6 Hue control circuit 7 Color demodulation circuit 8 Optical sensor 9 Optical sensor 10 Optical sensor 11 Composite circuit 12 Microcomputer 13 Hue control circuit

Claims (3)

[Claims] 1. At least one optical sensor for detecting a color change of external light incident on a screen display unit, and a hue for varying and outputting a phase of a subcarrier of a color signal based on an input from the optical sensor. An automatic hue adjuster comprising a control circuit and a color demodulation circuit that performs color demodulation using an input from the same hue control circuit and a color signal extracted from a video signal. 2. The automatic hue adjuster according to claim 1, wherein the optical sensor is an optical sensor that detects red light. 3. The optical sensor comprises an optical sensor for detecting red light, an optical sensor for detecting blue light, and an optical sensor for detecting green light. Comparing outputs from the respective optical sensors for calculation. 2. The automatic hue adjustment according to claim 1, further comprising: a control unit that outputs a control signal, wherein the phase of the subcarrier of the color signal is varied and output from the hue control circuit based on the control signal. vessel.