JPS60212089A - Television receiver - Google Patents

Abstract

PURPOSE:To obtain a white balance free from a change in temperature by correcting a temperature of a video input digital signal with the aid of an output of a thermo-sensor, by converting the corrected signal into an analog signal, simultaneously by processing it and by outputting a CRT drive signal. CONSTITUTION:Signals are inputted to thermo-offset generator circuits 22-24 for generating a thermo-offset and a thermo-gain due to output data 21 of a thermo-sensor 18 and Y, R-Y, B-Y thermo-gain data generator circuits 28-30, while digital input signals of three color difference systems are inputted to the circuits 28-30. Then a thermo-gain coefficient is multiplied by the input signal so as to correct thermo-gain data, and its output is inputted to adders 34-36, which add it to thermo-offset data 25-27 of the circuits 22-24 and input them to D/A converters 4-6. Then respective analog outputs performed a thermo-correction can be obtained and inputted to a matrix circuit 10. Finally and RGB signal and a CRT drive voltage can be obtained.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a television receiver.

Structure of a conventional example and its problems FIG. 1 shows the main structure of a conventional example which receives a video signal as an input. That is, l is the Y digital signal of the video input digital signal, 2 is the same <RY digital signal, 3 is the same <B
-Y digital signals, and these are the D/A converter 4.5
．． 6 and converted into analog signals 7 to 9, which are further processed to obtain RGB outputs 11 to 13 by the matrix circuit 10 and amplified by amplifiers 14, 15, and 16 to obtain output signals for driving the CRT 17. .

However, the analog signal processing circuits, that is, the D/A converters 4 to 6 . In the matrix circuit 10 and the amplifiers 14 to 16, since each temperature has a different temperature characteristic, the RGB CRT drive voltage that is the amplifier output is affected by the temperature and is proportional to the level of the digital signals 1 to 3. This has the disadvantage that the white balance changes due to temperature changes.

OBJECTS OF THE INVENTION The present invention eliminates the above-mentioned drawbacks and aims to provide a television receiver whose white balance is not affected by temperature changes.

Structure of the Invention The present invention corrects a video input digital signal using digital data obtained from a temperature sensor using a temperature correction means, converts the signal into analog, processes it, and outputs a CRT drive signal. . Since the correction bone by the temperature correction means compensates for the temperature characteristics of the processing circuit, it is possible to maintain a relationship between the input digital signal and the drive signal that is not affected by temperature changes.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention is shown in FIGS. 2 and 3. First, temperature is measured by the temperature sensor 18, and the measured analog temperature information 19 is converted into a digital temperature information signal 21 by the A/D converter 20. Signal 21 is Y, R-
Temperature offset data generation circuits 22 to 24 for Y and B-Y
Offcent digital data for temperature 2
5 to 27 are generated. Next, since this system targets a color difference method, there is a matrix circuit 10, and Y digital input signals 1. RY digital input signal 2. Since the circuit configuration from the 8-Y digital input signal 3 to the matrix circuit 10 is the same, only the Y digital input signal will be explained. That is, Y digital input signal 1
is input to the Y temperature gain meter generation circuit 28, and the temperature digital data signal 21 is input to the Y temperature gain data generation circuit 28. Here, inside the Y-layer temperature gain data generation circuit 28, as shown in FIG. 3, there is a temperature data versus temperature correction gain coefficient circuit 43, and this temperature data versus temperature correction gain coefficient circuit 43 outputs a correction gain depending on the temperature. A multiplier 44 performs multiplication with the Y digital input signal 1, and outputs a temperature-corrected Y signal 31 as an output obtained by temperature-correcting the input signal 1. This Y signal 31 is input to one of the adders 34, and the Y offset digital data 25 output from the Y temperature offset data generation circuit 22 is input to the input of the other adder 34. , the temperature-corrected Y signal data 37 is corrected for offset (DC value in analog terms) due to temperature, and then sent to the D/A converter 4 in the processing circuit.
is input.

The above is also performed on the R-Y signal 2 and the B-Y signal 3, and the RGB signals 11' to 11' are processed by the matrix circuit 10.
13' is obtained, R,
These become G and B CRT drive signals and are input to the CRT 17. In addition, if the temperature-related gain and DC level drift of the D/A converters 4 to 6, matrix circuit 10, amplifiers 14 to 16, etc. is known in advance, the temperature offset data generation circuit 22 is configured to correct the drift. By setting the temperature data versus output data in 23, 24, and setting the temperature data versus output data in the temperature gain data generating circuits 28, 29, and 30, the amplifiers 14, 15, .
16 outputs, completely temperature independent R,G
, B are output for the CRT drive.

In addition, 29 is an R-Y layer temperature gain data generation circuit, 30
is a BY layer temperature gain data generation circuit, 32.33 is their output signal, 35.36 is an adder, and 38.39 is its signal data.

In this way, in this embodiment, the analog temperature data obtained from the temperature sensor 18 is converted into digital temperature data (21) by the A/D converter 20, and the temperature offset and temperature gain are calculated using the digital temperature data (21). Three temperature offset generation circuits 22 to 24 and three temperature gain data generation circuits (comprised of a temperature data versus temperature gain coefficient generation circuit 43 and a multiplier 44) 28 to
30, and on the other hand, the three color difference digital input signals are input to each temperature gain data generation circuit 28 to 3o, temperature gain data is corrected by multiplying the input signal by the temperature gain coefficient, and the output is each adder 3
4 to 36, temperature offset data 25 to 27 output from the temperature offset generation circuits 22 to 24 described above are input to the other input, and the outputs of the three adders 34 to 36 three D/A converters 4 to 6
The CRT drive voltage is obtained by inputting temperature-corrected analog outputs to the matrix circuit 1o, obtaining RGB signals, and amplifying them respectively. As a result, the influence of temperature can be removed from the drive signal output from the amplifier, resulting in a stable circuit whose white balance is not affected by temperature.

Effects of the Invention As described above, according to the television receiver of the present invention, the input digital signal for video becomes an analog signal, and the CRT
Since the signal passes through an analog circuit before being applied to the signal, it is subject to gain changes due to temperature and DC level changes.
Since it has been corrected in advance, the effect of temperature can be removed, and the drive signal applied to the CRT is not affected by temperature, which has the effect that the white balance is not affected by temperature at all.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the configuration of the primary color drive D/A part according to a conventional example, FIG. 2 is a block diagram of the configuration of the primary color drive D/A part of an embodiment of the present invention, and FIG. 3 is a diagram of the temperature gain data generation circuit. FIG. 2 is a block diagram showing a specific example. 1 to 3...Y, RY, B-Y digital input signals (
video input digital device), 17...CRT, 18.
...Temperature sensor, 22-24...Temperature offset generation circuit (temperature correction means), 28-30...Y, R-Y
, B-Y temperature gain data generation circuit (temperature correction means)
, K...processing circuit

Claims (1)

[Claims] A temperature sensor, a temperature correction means for temperature-correcting an input digital signal for video using digital data based on the temperature sensor, and a CRT drive signal is generated by converting and processing the input digital signal corrected by the temperature correction means into analog. A television receiver equipped with a processing circuit.