JP3307244B2 - Bright data control circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for moving user adjustment data in a television receiver.
The present invention relates to a bright data control circuit for providing that on-screen characters on a screen are always visible.

[0002]

2. Description of the Related Art In recent years, with the increase in the size of color television receivers, high-quality television receivers have been desired.
Regardless of how the user adjustment data is moved, a bright data control circuit that always makes on-screen characters on the screen visible is regarded as important.

Hereinafter, an example of the above-described conventional bright data control circuit will be described with reference to the drawings.

FIG. 3 is a block diagram showing a conventional bright data control circuit. In the block diagram of FIG. 3, reference numeral 301 denotes a character or the like on a monitor .
On-screen signal and video R made by microcomputer
A superimposed signal on which a GB signal is superimposed is input, and the
Contrast control circuit that can adjust the amplitude level
Path, 302 is the amplitude level of the contrast control circuit 301
Control data, and the output data is
Contrast system input to the contrast control circuit 301
A control data generation circuit 304;
1 can vary the DC component of the superimposed signal output from
The superimposed signal output from the
Bright control circuit input to the driving circuit, 303 is a bright control circuit.
For controlling the DC level of the load control circuit 304
Is a bright control data generation circuit .

The operation of the bright data control circuit configured as described above will be described below.

First, the contrast control data generating circuit 3
02, the control data is generated by the bright control data generation circuit 303, and the contrast control circuit 301,
It is input to the bright control circuit 304 to control each of them. At this time, the on-screen character signal on the screen moves in conjunction with the brightness control and the contrast control of the television signal.

[0007]

However, the above configuration has the following problems.

FIG. 4 is a diagram for explaining the operation of a conventional bright control circuit. FIG. 4 (a) conceptually shows the on-screen signal level at the RGB output point when the brightness is in a standard state. (B) conceptually shows the on-screen signal level at the RGB output point when contrast and bright are in the MIN state.
(A) is 3 from the standard petestal voltage (cut-off voltage).
It is shown that the signal is an on-screen signal having an amplitude of V. When the contrast is set to MIN, the amplitude of 3V becomes 1V
When the brightness is reduced to MIN, the petestal voltage decreases by 1 V, and the on-screen signal is in the state shown in FIG. That is, since the highest level of the on-screen signal becomes the same level as the standard petestal voltage (cut-off voltage), there is a problem that the on-screen signal cannot be seen on the screen.

[0009]

In order to solve the above problems, a bright data control circuit according to the present invention comprises a contrast control circuit, a contrast control data generation circuit, a bright control data generation circuit, and a contrast MAX data storage circuit. , A subtraction circuit, a division circuit, an addition circuit, a bright MIN data storage circuit, a bright control data clip circuit, and a bright control circuit.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the first aspect of the present invention, a superimposed signal in which an on-screen signal generated by a microcomputer or the like and a video RGB signal are superimposed for displaying characters on a monitor is input. A contrast control circuit capable of adjusting the amplitude level of the signal; and data for controlling the amplitude level of the contrast control circuit. The output data is contrast control data input to the contrast control circuit. A generating circuit; a DC component of a superimposed signal output from the contrast control circuit can be varied; a superimposed signal output therefrom is used as a bright control circuit input to a drive circuit of a display device; and contrast MAX data storage circuit for storing the maximum data generating circuit can output, the Contrast MAX data storage circuit
From the contrast MAX data output from the
Subtract the output data of the trust control data generation circuit
A subtraction circuit, and an output signal from the subtraction circuit having a predetermined value.
A division circuit for dividing in, to store Bright MIN data
A bright MIN data storage circuit, an addition circuit for adding output data of the division circuit and output data of the bright MIN data storage circuit, and a direct control circuit of the bright control circuit.
Bright system to generate data to control flow level
A control data generating circuit, and a lower limit of output data from the bright control data generating circuit is determined by output data from the adding circuit, and the output data is input to the bright control circuit and operates as a lower limit clip. and a clipping circuit, even how to move the user adjustment data, the on-screen characters on the screen
Der those There was always a bright data control circuit, characterized in that to be displayed, so as to change the bright control range by the state of the contrast data
You .

According to a second aspect of the present invention, a contrast control circuit, a contrast control data generation circuit,
A brightness control data generation circuit, a contrast MAX data storage circuit, a subtraction circuit, a division circuit, an addition circuit, a brightness MIN data storage circuit, a brightness control data clipping circuit, and a brightness control circuit; The bright data control circuit is characterized in that on-screen characters on the screen are always visible no matter how it moves, and has the effect of changing the bright control range depending on the state of contrast data.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. (Embodiment) FIG. 1 shows a block diagram of a bright data control circuit according to an embodiment of the present invention. In FIG. 1, reference numeral 101 denotes a contrast control circuit;
02 is a contrast control data generation circuit, 103 is a bright control data generation circuit, and 104 is a contrast MAX.
A data storage circuit, 105 is a subtraction circuit, 106 is a division circuit, 107 is an addition circuit, 108 is a bright MIN data storage circuit, 109 is a bright control data clip circuit, and 110 is a bright control circuit.

The operation of the bright data control circuit configured as described above will be described below with reference to FIGS.

First, the operation will be described with reference to FIG.
The data output from the contrast control data generation circuit 102 is input to the contrast control circuit 101, and is input to the subtraction circuit 105 at the same time as performing contrast control, and is subtracted from the data from the contrast MAX data storage circuit 104. The output data of the subtraction circuit 105 is divided by a certain constant by a division circuit 106 and input to an addition circuit 107. Bright MIN is added to the addition circuit 107.
Data from the data storage circuit 108 is also input.
The bright control data clipping circuit 109 is a circuit for clipping the bright control data output from the bright control data generating circuit 103 so as not to be lower than the bright MIN clip data output from the adding circuit 107. The data output from the brightness control data clip circuit 109 is input to the brightness control circuit 110 to perform brightness control.

FIG. 2 is a diagram for explaining the operation of the bright data control circuit according to the first embodiment of the present invention.
9A, the horizontal axis represents the contrast control data generation circuit 102.
The vertical axis is the bright MIN clip data output from the addition circuit 107. According to the block diagram of FIG. 1, the bright MIN clip data changes depending on the state of the contrast control data. When the bright MIN clip data changes, as shown in FIG.
Since the brightness control range (bright MIN data) at the time can be changed, contrast, bright MIN
Does not make the on-screen characters invisible on the screen.

[0016]

As described above, according to the present embodiment, the contrast control circuit, the contrast control data generation circuit, the bright control data generation circuit, and the contrast MA
By providing an X data storage circuit, a subtraction circuit, a division circuit, an addition circuit, a bright MIN data storage circuit, a bright control data clip circuit, and a bright control circuit, no matter how the user adjustment data is moved. You can expect the effect that the on-screen characters on the screen are always visible.

[Brief description of the drawings]

FIG. 1 is a block diagram of a bright data control circuit according to an embodiment of the present invention.

FIG. 2 is an operation explanatory diagram of FIG. 1;

FIG. 3 is a block diagram of a conventional bright data control circuit.

FIG. 4 is an operation explanatory diagram of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 101 Contrast control circuit 102 Contrast control data generation circuit 103 Bright control data generation circuit 104 Contrast MAX data storage circuit 105 Subtraction circuit 106 Division circuit 107 Addition circuit 108 Bright MIN data storage circuit 109 Bright control data clip circuit 110 Bright control circuit

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁷ Identification code FI G09G 5/40 G09G 5/40 H04N 5/57 H04N 5/57 JP-A-9-135403 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04N 5/38-5/46 H04N 5/262-5/278 H04N 5/50-5 / 63

Claims (1)

(57) [Claims] 1. An on-screen signal and video RGB generated by a microcomputer or the like for displaying characters and the like on a monitor.
A contrast control circuit capable of inputting a superimposed signal on which a signal is superimposed and adjusting the amplitude level of the signal, and generating data for controlling the amplitude level of the contrast control circuit, the output data of which is A contrast control data generating circuit input to a contrast control circuit, and a DC component of a superimposed signal output from the contrast control circuit can be varied. The superimposed signal output therefrom is input to a drive circuit of a display device. that the Bright control circuit, and contrast MAX data storage circuit for storing the maximum data the contrast control data generating circuit can be output, the contrast MAX de
MAX data output from the data storage circuit
From the output data of the contrast control data generation circuit
Subtraction circuit, a division circuit for dividing an output signal from the subtraction circuit by a predetermined value, and a bright MIN decoder.
And Bright MIN data storage circuit for storing a over data, an adding circuit for adding the output data of the output data and the bright MIN data storage circuit of the dividing circuit, the Bright
Generates data for controlling the DC level of the control circuit
And a lower limit of output data from the bright control data generating circuit is determined by output data from the adder circuit, and the output data is input to the bright control circuit and operates as a lower limit clip. and a control data clipping circuit, even how to move the user adjustment data, Bright data control circuit, characterized in that the on-screen characters on the screen are always to be displayed.