JP3303318B2 - On-screen display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-screen display device such as a television receiver.

[0002]

2. Description of the Related Art On the screen of a conventional television receiver or the like, there is provided an on-screen function for displaying various information of the television receiver itself such as a channel selection and a volume on the screen by an output signal of a channel selection microcomputer. Has been added. FIG. 2 shows a schematic block diagram of a conventional on-screen function. In the figure, 1 controls various information of the television receiver,
The channel selection microcomputer 1 outputs an RGB signal for displaying the contents on-screen. In the figure, reference numeral 2 denotes a clock countermeasure coil 2 for making it difficult to pass the clock components of the RGB signals output from the tuning microcomputer 1. Reference numeral 3 denotes an amplifier having a function of synthesizing and amplifying a television signal. Reference numeral 4 denotes a CRT unit for displaying a signal synthesized and amplified by the amplifier 3. 5 is the output RG of the tuning microcomputer 1
B signal, 6 is RGB after passing through the coil for clock disturbance prevention
Signal, 7 is the RGB signal of the television signal, 8 is the RGB signal after the combined amplification of the television signal and the on-screen signal
A signal 9 is a power supply for the channel selection microcomputer.

The operation of the on-screen function configured as described above will be described below. The RGB signal output by the tuning microcomputer 1 is greatly affected by the microcomputer operating clock, and has a high frequency clock disturbance. To reduce this interference, a clock interference countermeasure coil is connected to each RGB signal.
The R'G'B 'signal in which the clock disturbance is reduced is synthesized and amplified by a general television signal and the amplifier 3 and displayed on the CRT 4.

[0004] These operations are in a normal state, but what matters here is the R'G'B 'signal 6 output by the clock interference countermeasure coil 2. This R'G'B '
Although the interference of the signal 6 is reduced by the clock interference countermeasure coil 2, it is not completely eliminated.
A little clock component remains. Therefore, the R′G′B ′ signal 6 including the clock component reaches the CRT 4 and is displayed.

[0005]

The RGB signal 5 containing the clock disturbance component output from the channel selection microcomputer 1 is reduced by the clock disturbance countermeasure coil 2, but the clock disturbance itself is not eliminated. Therefore, since it is combined with a general television signal and amplified, there is a problem that when the channel selection microcomputer 1 outputs the RGB signal 5, it is always slightly displayed on the CRT 4.

The present invention has been made in view of the above problems, and provides an on-screen display device free from clock interference.

[0007]

[Means for Solving the Problems] In order to solve the above-mentioned problems
The on-screen display device of the present invention
Supply the power supply voltage to the tuning microcomputer used in the receiver
And a data output from the tuning microcomputer.
Circuit for countermeasures against clock disturbance to which digital RGB signal is input
And supplying a power supply voltage to the clock disturbance countermeasure circuit.
A second power supply, and output from the tuning microcomputer.
When the digital RGB signal is high, the second
From the clock interference countermeasure circuit to the microcomputer
Output a high level according to the output signal from
And is operated by the first power supply for operating the microcomputer.
Frequency superimposed on the output signal from the tuning microcomputer
Clock disturbance caused by high-frequency clock disturbance signals
Operating by a second power supply different from the first power supply for
In the clock interference countermeasure circuit.
It is characterized by having done.

[0008]

According to this configuration, clock disturbance does not appear on the on-screen display, and a screen without a sense of incongruity is displayed.

[0009]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration according to an embodiment of the present invention. FIG. 1 is a block diagram showing an on-screen display device according to an embodiment of the present invention.

In the figure, 1 is a channel selection microcomputer, 2 is a clock interference countermeasure circuit, 3 is an amplifier, 4 is a CRT, 5 and 6 are RGB signals for displaying an on-screen display, 7 is an RGB signal for displaying a television signal, 9 Is a power supply for operating the channel selection microcomputer. The above is the same as the configuration in FIG. Reference numeral 10 denotes a power supply for countermeasures against clock disturbance, which is a power supply different from the power supply for operation of the tuning microcomputer 1 or a power supply of a different system.

The operation of the thus configured on-screen display device will be described below.
The on-screen display device 5 output from the channel selection microcomputer 1 is input to a clock interference countermeasure circuit 2 having a power source different from that of the channel selection microcomputer 1 or a power source of another system. Here, since the RGB signal 5 for on-screen display is a digital signal, when it is at a high level, the power supply 10 of the clock disturbance countermeasure circuit 2 outputs a high level.
That is, the signal is output as the on-screen display R'G'B 'signal 6, is synthesized and amplified by the amplifier 3 with a general television signal, and an on-screen signal without clock disturbance is displayed on the CRT 4.

As described above, according to this embodiment, a screen without clock disturbance can be displayed by using a separate power supply or a separate power supply for the clock disturbance prevention circuit.

[0013]

As described above, the on-screen table of the present invention is described.
According to the display device , the power supply voltage is supplied to the tuning microcomputer.
The first power supply is a separate power supply or a second power supply of another system .
By arranging the clock disturbance prevention circuit used ,
Clock that could not be completely removed by the anti-jam coil
The interfering signal can be completely removed, and clear on-screen display without clock interference can be achieved, and the effect is great.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of an on-screen display device according to an embodiment of the present invention.

FIG. 2 is a schematic block diagram of a conventional on-screen display device.

[Description of Signs] 1 Tuning microcomputer 2 Clock disturbance countermeasure circuit 3 Amplifier 4 CRT 5 RGB signal (RGB signal before countermeasure against clock disturbance) 6 R'G'B 'signal (RGB signal after countermeasure against clock disturbance) 8 After amplification RGB signal 9 Power supply for channel selection microcomputer 10 Power supply for clock disturbance prevention circuit

Claims (1)

(57) [Claims] A first power supply for supplying a power supply voltage to a tuning microcomputer used in a television receiver;
Digital RGB signal output from the microcomputer
Clock disturbance countermeasure circuit and clock disturbance countermeasure
A second power supply for supplying a power supply voltage to the circuit for use,
The digital RGB signal output from the tuning microcomputer is
The clock disturbance due to the second power supply
C from the countermeasure circuit according to the output signal from the microcomputer.
Output for the microcomputer operation.
From the channel selection microcomputer operated by the first power supply
High frequency clock interference signal superimposed on the signal
The clock disturbance caused by the clock disturbance is operated by a second power supply different from the first power supply for operating the microcomputer .
An on-screen display device , which is removed in a circuit .