JPH08228318A - Television receiver - Google Patents

Abstract

PURPOSE: To provide a television receiver provided with an automatic sub-bright adjusting function capable of eliminating manual adjusting work and performing adjustment with high accuracy when the sub-bright of the televison receiver is adjusted. CONSTITUTION: When an automatic adjusting mode is started, it is judged whether or not an inputted television signal is a regular signal, and when it is the regular signal, a microcomputer 2 sets contrast and the adjusting voltage of a luminance level at zero. A voltage level from a beam current detection circuit 8 at that time is inputted to the microcomputer 2, and when the level exceeds VDD/2 (reference value) for the operating power source VDD of the microcomputer 2, a beam current detection voltage is set as the reference voltage A. After that, luminance and the contrast are set at a reference adjusting voltage, and the luminance level is automatically adjusted by the microcomputer so as to be set at a differential voltage B decided in advance for the reference voltage A, and when the differential voltage B is obtained, such data is stored in memory 1 as sub-bright data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit for adjusting the brightness of a television receiver, and more particularly, to a brightness adjusting circuit and its brightness adjusting circuit for presetting the maximum brightness of the television receiver. The present invention relates to a television receiver provided.

[0002]

2. Description of the Related Art Conventionally, there are two types of television receivers, a luminance adjustment that can be adjusted by the user and a luminance adjustment (hereinafter referred to as subbright adjustment) that is adjusted by the manufacturer. In this sub-bright adjustment, the reference video signal is input to the television receiver, the voltage across the resistor for measuring the anode current of the cathode ray tube (hereinafter referred to as CRT) is measured with a voltmeter, and the brightness is adjusted. The semi-fixed resistor VR was adjusted to a preset reference value (maximum brightness is set). For example, the technique of adjusting using the VR in this way is described on pages 138 to 1 of the NHK Color Television Textbook (above) published by the Japan Broadcasting Corporation on April 1, 1983.
It is described on page 39.

In recent years, a television in which tuning data, adjustment data such as contrast and brightness are stored in a memory, and the data is supplied from a microcomputer (hereinafter referred to as a microcomputer) to a predetermined circuit. A John image receiver is proposed in Japanese Patent Laid-Open No. 61-95629 (H04B1 / 16).

Even in such a television receiver controlled by a microcomputer, the above-mentioned sub-bright adjustment is
I was still adjusting with a variable resistor. This conventional technique is shown in FIG.
Shown in

In FIG. 2, 1 is a memory for storing tuning data and adjustment data such as contrast and brightness, 2 is a microcomputer for performing various controls of a television receiver, 3 is brightness adjustment data (PWM: pulse) from the microcomputer 2. D / A converter circuit for converting (waveform modulation output) into analog voltage, 4 tuner, 5 video / chroma IC, 6 CRT, 7 C
A high voltage generating circuit for supplying high voltage to RT6, VR is a variable resistor for adjusting sub-bright, 9 is a remote control transmitter for the user to give a command to the television receiver, and 10 is a remote control signal from the remote control transmitter 9. Microcomputer 2 receiving
It is a remote control light receiving unit that supplies a remote control signal to

In the television receiver as described above, the user performs a desired operation from the remote control transmitter 9, a remote control signal according to the operation is transmitted, and the remote control light receiving unit 10 receives the remote control signal and outputs the remote control signal. It is supplied to the microcomputer 2. After that, the microcomputer 2 performs control corresponding to the remote control signal. For example, when a tuning operation is performed, the microcomputer 2 reads out tuning data of a designated tuning channel from the memory 1, outputs tuning data to the tuner 4, and converts the data into an analog signal. Supply tuning voltage to tuner.

On the other hand, when the user adjusts the brightness,
The remote control transmitter 9 is operated to output a remote control signal for brightness adjustment, and the remote control light receiving unit 10 supplies the remote control signal to the microcomputer 2. When the power of the television receiver is turned on, the microcomputer 2 stores the brightness adjustment voltage data in the memory 1 as the brightness adjustment voltage data set before the power is turned off. Video / chroma IC5 via A conversion circuit 3
Adjust the brightness by controlling the brightness adjustment terminal of. Although only the brightness adjustment is shown here, other adjustments such as contrast are also made in the same manner.

On the other hand, when the sub-bright adjustment is performed, the variable resistor V remains unchanged as described at the beginning.
Must be adjusted using R, and this subbright adjustment is the most complicated step in the manufacturing process,
Furthermore, since it is a manual adjustment by a person, it is not always sufficient in terms of workability and accuracy of the adjustment.

[0009]

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned problems, and when performing sub-bright adjustment of a television receiver, manual adjustment work can be eliminated and accurate adjustment can be performed. A television receiver having an automatic sub-bright adjustment function is provided.

[0010]

SUMMARY OF THE INVENTION According to the present invention, a command section for giving a command to a user to perform a desired operation on a television receiver, and tuning tuning voltage data and video to be supplied to a tuner of the television receiver are provided. A memory unit that stores adjustment data supplied to the video signal processing circuit of the television receiver for adjusting various level adjustments such as the brightness and contrast of the signal, and the data stored in the memory unit is read, and the data is read out. It supplies the various circuits of the television receiver, and also supplies the video output obtained from the above-mentioned video signal processing circuit and a control section that receives various command signals from the command section and performs various controls of the television receiver. Television receiver including a cathode ray tube for displaying an image by a beam and beam current detecting means for detecting a beam current flowing through the cathode ray tube In the above, the control unit sets the voltage for adjusting the brightness and the contrast to the minimum value, and detects the beam current level of the beam current detection means when the television receiver receives a video signal having a low modulation degree, The level is stored in the memory, and then the voltage supplied to the video signal processing circuit for adjusting the brightness and the contrast is output so as to be in the standard position, and the predetermined difference level with respect to the beam current level is output. The television receiver is characterized in that the brightness level is automatically adjusted so that the adjusted level is stored in the memory.

Further, the present invention is a television receiver characterized in that the brightness level automatically adjusted by the control unit is a level adjusted to an optimum black level of a video signal.

Further, according to the present invention, a command section for giving a command for a user to perform a desired operation on the television receiver, a tuning tuning voltage data supplied to the tuner of the television receiver and a luminance of the video signal and A memory unit for storing adjustment data to be supplied to a video signal processing circuit of a television receiver for adjusting various level adjustments such as contrast, and the data stored in the memory unit is read out and the data is received by the television receiver. And a video output obtained from the above video signal processing circuit, and an image is displayed by a control section for receiving various command signals from the command section and performing various controls of the television receiver. A cathode ray tube, a high voltage generating means for supplying a high voltage to the cathode ray tube, and a beam current flowing through the cathode ray tube. In a television receiver provided with a beam current detecting means for detecting a change in the high voltage generating means to detect a beam current, the control section sets a voltage for adjusting brightness and contrast to a minimum value, The beam current level of the beam current detecting means when the receiver receives a video signal having a low modulation degree is detected, the level is stored in the memory, and then the brightness and contrast supplied to the video signal processing circuit are detected. The voltage to be adjusted is output so as to be in the standard position, the brightness level is automatically adjusted to a predetermined difference level with respect to the beam current level, and the adjusted level is stored in the memory. It is a television receiver characterized in that

Further, the present invention is the television receiver, wherein the brightness level automatically adjusted by the control unit is a level adjusted to an optimum value of the black level of the video signal.

[0014]

The present invention, by having the above-mentioned configuration,
Reference voltage A obtained by detecting the anode current flowing in the CRT
The brightness is adjusted by the microcomputer so that the brightness automatically approaches the constant difference voltage B, and the difference voltage B
When the value becomes, the value can be stored in the memory and used as the sub-bright voltage.

[0015]

The present invention will be described below with reference to the drawings. FIG.
Shows an embodiment of the present invention. In FIG. 1, the same drawing numbers as those in FIG. 2 are the same, and therefore the description thereof will be omitted. 1 is different from FIG. 2 in that an anode current detection circuit 8 is provided and the function of the microcomputer 2 is added with the flowchart of FIG.

First, the anode current detection circuit 8 includes a resistor R
1, R2, R3, R4, diodes D1, D2, Zener diode ZD, power supply + B, CR
It is converted into a DC voltage based on the average value of the anode current flowing at T6. For example, if the anode current does not flow, the resistance R
The voltage divided by 1, R2 and the diode D1 becomes maximum, and is converted and supplied so as to have a voltage level to be supplied to the microcomputer 2 through the Zener diode ZD. On the other hand, when the anode current flows, the voltage divided by the resistors R1 and R2 and the diode D1 becomes smaller, and a voltage proportional to this is supplied to the microcomputer 2. As a result, a voltage proportional to the average value of the anode current is supplied to the microcomputer 2. Although these detected voltages are supplied to the microcomputer 2, they are supplied to an A / D input terminal (not shown) of the microcomputer 2.

Now, the relationship between the average value of the anode current and the input voltage to the microcomputer 2 will be described. This relationship is as shown in FIG. 3, and each component in the anode current detection circuit 8 is selected under the condition that the anode current is 0 so that the input voltage of the microcomputer 2 becomes the maximum voltage. The power supply voltage VDD is determined not to exceed VDD / 2 or higher.

By designing a desired anode current for a predetermined video signal by the graph of FIG. 3, the input voltage to the microcomputer 2 at this time and the differential voltage when the anode current is 0 are also designed. It can be set as a reference value for time.

Therefore, in the present invention, the input voltage of the microcomputer 2 when the anode current is 0 is set to the reference voltage A, and the differential voltage as the design reference value is set to B.

Thereafter, the microcomputer 2 operates as follows based on the detected voltage from the anode current detection circuit 8. First, a television signal for automatic adjustment is connected to an antenna (not shown) connection part of a television receiver or a video input part (not shown). This television signal is a signal with a modulation degree as low as possible (a television signal with a constant DC voltage level in order to prevent the influence of the anode current due to the image quality variation in the video signal processing circuit depending on the set of television receivers). ).

Next, the operation of the microcomputer 2 will be described with reference to the flowchart of FIG. First, an automatic adjustment start switch (not shown) of the remote control transmitter 9 is operated to transmit an automatic adjustment start remote control signal, and the remote control light receiving unit 10 receiving the remote control signal supplies the remote control signal to the microcomputer 2. The microcomputer 2 enters the automatic adjustment mode when receiving the remote control signal.

First, when the automatic adjustment mode (S1) is entered,
It is determined whether the input television signal is a regular signal or whether an antenna (not shown) cable is correctly connected to the device (S2). Specifically, this judgment is
The determination is made based on the input of the AFT input to the microcomputer 2 and the sync signal obtained from the sync separation circuit (not shown). Such determination is made, for example, in Japanese Examined Patent Publication No. 61-110.
AF as shown in Japanese Patent Publication No. 27 (H04N5 / 44)
When a T signal is present and a synchronizing signal is present, it is determined that a regular television signal is being input.

If it is determined in this synchronization input determination (S2) that there is no synchronization signal (no regular television signal is input), the process is regarded as an error (S12) and the process is terminated (S13).

Next, when it is determined that a sync signal is present (a regular television signal is input), the PWM output from the microcomputer for brightness and contrast is set to the minimum (0) level as an initial setting (S3). .

The signal level of the input television signal is a signal with a low degree of modulation (a dark screen signal).
, The output drive of the CRT 6 is in a cut-off state, the beam current from the high voltage generation circuit 7 is not supplied, and the beam current detection circuit 8 sets the output to the maximum voltage and the A / D input terminal of the microcomputer 2. Is input to (S
4).

Thereafter, the input television signal is
It is determined whether the signal has a predetermined low modulation factor (S5). This determination is based on the microcomputer 2 described earlier.
When the maximum voltage input to the A / D input terminal is less than VDD / 2 (that is, when the maximum voltage is less than VDD / 2 as shown in FIG. 3, it can be seen that the beam current is flowing, so If it can be determined that a low signal is not input), it is determined that the signal does not have a low modulation degree, and it is processed as an error (S
12) and ends (S13).

On the other hand, when it is determined that the signal has a low modulation degree, the above-mentioned maximum voltage input to the A / D input terminal of the microcomputer 2 is stored in the memory 1 as the reference voltage A (S).
6).

After that, the PWM output from the microcomputer 2 for the brightness and the contrast to the video / chroma IC 5 is returned to the standard position so that the PWM output for controlling the brightness can be automatically changed (S7). Then, the voltage of the A / D input terminal of the microcomputer 2 at that time is detected (S
8) It is determined whether the detected voltage is the value (preset) of the difference voltage B from the reference voltage A described above as shown in FIG. 3 (S9), and the difference voltage B is set. The PWM output is automatically changed (S10).

Finally, when the difference voltage B is reached, the PWM
The output data is stored in the memory 1 (S11), and the automatic adjustment mode ends (S13). The PWM output data stored in the memory 1 has a value corresponding to the sub-bright adjustment conventionally performed by the variable resistor at the time of factory shipment.

In the production process, whether these programs normally work or error-processed, the results should be processed so that they can be displayed on the display on the CRT 6. Since the confirmation of the result of the automatic adjustment can be easily confirmed, even in the unmanned production process, it can be visually confirmed in the subsequent manned production process.

[0031]

As described above, according to the present invention, since the adjustment of the sub-bright can be automated in the production process of the television receiver, there is an effect that the adjustment work becomes unnecessary and the adjustment accuracy can be performed without impairing the adjustment accuracy. . Furthermore, since there is no need for human adjustment, there is a great effect that the efficiency of the production process can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram showing a conventional technique.

FIG. 3 is a diagram showing a relationship between an anode current and an anode current detection voltage input to a microcomputer for explaining an embodiment of the present invention.

FIG. 4 is a flowchart showing the operation of the embodiment of the present invention.

[Explanation of symbols]

 1 Memory 2 Microcomputer 3 D / A Conversion Circuit 4 Tuner 5 Video / Chroma IC 6 CRT 7 High Voltage Generation Circuit 8 Anode Current Detection Circuit 9 Remote Control Transmitter 10 Remote Control Receiver

Claims (4)

[Claims] 1. A command section for giving a command for a user to perform a desired operation on a television receiver, and various tuning tuning voltage data supplied to a tuner of the television receiver and brightness and contrast of a video signal. Memory unit for storing the adjustment data supplied to the video signal processing circuit of the television receiver for adjusting the level adjustment of the data, and the data stored in the memory unit is read out and the data is read into various circuits of the television receiver. A control unit which supplies the command signal given from the command unit and controls various operations of the television receiver; and a cathode ray tube which supplies the video output obtained from the video signal processing circuit to display an image. A television receiver including beam current detection means for detecting a beam current flowing through the cathode ray tube, , The voltage for adjusting brightness and contrast is set to the minimum value, the beam current level of the beam current detection means when the television receiver receives a video signal having a low modulation degree is detected, and the level is stored in the memory. After that, the voltage supplied to the video signal processing circuit for adjusting the brightness and the contrast is output so as to be in the standard position, and the brightness level is adjusted so that the beam current level becomes a predetermined difference level. A television receiver characterized in that it is automatically adjusted and the adjusted level is stored in the memory. 2. The television receiver according to claim 1, wherein the brightness level automatically adjusted by the controller is a level obtained by adjusting the black level of the video signal to an optimum value. Television receiver to do. 3. A command unit for giving a command for a user to perform a desired operation on a television receiver, and various kinds of tuning tuning voltage data supplied to a tuner of the television receiver and brightness and contrast of a video signal. Memory unit for storing the adjustment data supplied to the video signal processing circuit of the television receiver for adjusting the level adjustment of the data, and the data stored in the memory unit is read out and the data is read into various circuits of the television receiver. A control unit which supplies the command signal given from the command unit and controls various operations of the television receiver; and a cathode ray tube which supplies the video output obtained from the video signal processing circuit to display an image. A high voltage generating means for supplying a high voltage to the cathode ray tube, and the high voltage voltage for detecting a beam current flowing through the cathode ray tube. In a television receiver comprising a beam current detecting means for detecting a change in the live means and detecting a beam current, the control unit sets a voltage for adjusting brightness and contrast to a minimum value, and the television receiver is A voltage for detecting the beam current level of the beam current detecting means when a video signal having a low modulation degree is received, storing the level in the memory, and then adjusting the brightness and contrast supplied to the video signal processing circuit. Is output so as to be in a standard position, the brightness level is automatically adjusted so as to have a predetermined difference level with respect to the beam current level, and the adjusted level is stored in the memory. A television receiver characterized in that 4. The television receiver according to claim 3, wherein the luminance level automatically adjusted by the control unit is a level obtained by adjusting the black level of the video signal to an optimum value. Television receiver to do.