JPH1070690A - Video image controller for television receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce production of noise by multiplexing a teletext display signal and a control signal and sending the resulting signal between a control microcomputer and a video image system LSI so as to reduce number of wires between the control microcomputer and the video image system LSI. SOLUTION: A signal multiplexer circuit 12 selects a teletext display signal generating circuit 8 for a teletext display signal transmission period and a signal separator circuit 1 selects a teletext display signal processing circuit 11 simultaneously and a teletext display signal is fed to a signal line 14. When a vertical synchronizing signal produced from a color video signal by a synchronization deflection section 5 or the like is given to the circuit 12, a control signal transmission period is set and the signal multiplexer circuit 12 selects a control signal processing circuit 10 and the signal separator circuit 13 selects the control section processing circuit 10 and a control signal is fed to the signal line 14. When the teletext display signal transmission period is set, the signal multiplexer circuit 12 selects the teletext display signal generating circuit 8 and the signal separator circuit 13 selects the teletext display signal processing circuit 11 and the teletext display signal is fed again to the signal line 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention reduces the number of signal lines by multiplexing a character display signal and a control signal transmitted between a control microcomputer and a video LSI in a television receiver. The present invention relates to a video control device capable of reducing noise generation.

[0002]

2. Description of the Related Art Video, audio,
There are various sections such as channel selection, and a control microcomputer is used to control them. In addition to the control signals for controlling the various parts of the television receiver, the control microcomputer also sends character display signals for displaying characters and numbers on the screen when the channel is changed or the volume is adjusted. ing.

FIG. 9 shows a basic configuration of a general television receiver.

In FIG. 9, this television receiver selects a channel selection unit 1 for extracting a signal of a desired reception channel from a television signal received by an antenna, and separates a video signal and an audio signal to extract a color video signal. Video receiver 2
And the color signal is extracted from the color video signal and RGB 3
A color signal reproducing section 3 for producing a primary color signal, an audio receiving section 4 for extracting television audio and operating a speaker, a synchronous deflecting section 5 for extracting a synchronous signal from a color video signal and producing horizontal and vertical synchronous signals, and a tuning section 1; The microcomputer 6 includes a control microcomputer 6 for controlling the color signal reproducing unit 3 and the audio receiving unit 4, and other components such as a color output, a color picture tube, and a speaker.

In this television receiver, a control microcomputer 6 controls a channel selection control signal for controlling the channel selection section 1, a video / color control signal for controlling the color signal reproduction section 3, and an audio reception section 4. Control data such as a voice control signal for performing the operation. Further, between the control microcomputer 6 and the color signal reproducing unit 3, in addition to the video / color control signal, a channel number and the like are displayed on the screen when the channel is changed or the volume is changed. A character display signal is also transmitted. These signals are transmitted to a video LSI in the color signal reproducing unit 3 and used for controlling the color signal reproducing unit 3 and processing the color signals.

FIG. 10 shows signal transmission between the control microcomputer 6 and the video LSI.

As shown in FIG. 10, the control microcomputer 6 has a control signal generation circuit 7 and a character display signal generation circuit 8, and the video LSI 9 includes a control signal processing circuit 10, a character display signal processing circuit 11, have.

In the conventional signal transmission between the control microcomputer 6 and the video LSI 9, the control signal is a control signal generation circuit 7
And the control signal processing circuit 10 are connected by a control signal line, and the character display signal is performed by connecting the character display signal generation circuit 8 and the character display signal processing circuit 11 by a character display signal line. Therefore, transmission of the control signal and the character display signal has been performed separately.

[0009]

However, according to the above-described signal transmission between the control microcomputer and the video LSI, the control signal line and the character display signal line are separately required. The occupied area occupied by wiring on the printed circuit board has increased, and the design has become complicated. In addition, since each of the wirings is a source of noise, the large number of signal lines leads to the generation of more noise. Further, the number of pins required for the microcomputer and the video LSI is also increased, which causes an increase in cost.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to reduce the complexity of wiring design in signal transmission between a microcomputer for controlling a television receiver and a video LSI. Another object of the present invention is to provide a video control device which realizes a reduction in noise, a reduction in the number of required pins, and a cost increase.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a control signal generating means for generating a control signal for controlling each part of a television receiver, and a method for displaying characters on a screen of the television receiver. A character display signal generating means for generating a character display signal to be displayed, a signal multiplexing means for multiplexing the character display signal and the control signal, and a signal line for transmitting a signal multiplexed by the signal multiplexing means Signal separating means for separating the multiplexed signal transmitted by the signal line into the character display signal and the control signal; and a control signal processing for processing the control signal separated by the signal separating means. And character display signal processing means for processing the character display signal separated by the signal separation means.

According to the above configuration, since the character display signal and the control signal are multiplexed and transmitted between the control microcomputer and the video LSI, the number of wirings is reduced. As a result, design complexity is eliminated, and the occurrence of noise can be reduced.

It is particularly effective when combined with a video LSI that requires serial data transfer under microcomputer control.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a basic configuration of a general television receiver when the video control apparatus according to the first embodiment of the present invention is implemented. In the figure, the same reference numerals are given to portions overlapping with FIG. 9 (conventional example).

In FIG. 1, the television receiver selects a signal of a desired receiving channel from a television signal received by an antenna, and separates a video signal and an audio signal to extract a color video signal. Video receiver 2
And the color signal is extracted from the color video signal and RGB 3
A color signal reproducing section 3 for producing a primary color signal, an audio receiving section 4 for extracting television audio and operating a speaker, a synchronous deflecting section 5 for extracting a synchronous signal from a color video signal and producing horizontal and vertical synchronous signals, and a tuning section 1; The microcomputer 6 includes a control microcomputer 6 for controlling the color signal reproducing unit 3 and the audio receiving unit 4, and other components such as a color output, a color picture tube, and a speaker.

In this television receiver, the control microcomputer 6 controls a tuning control signal for controlling the tuning section 1, a video / color control signal for controlling the color signal reproducing section 3, and controls the audio receiving section 4. Control data such as a voice control signal for performing the operation.

The control microcomputer 6 and the color signal reproducing unit 3
In addition to the video / color control signal, a character display signal for displaying a channel number or the like on the screen when the channel is changed or the volume is changed is also transmitted between the two. These signals are transmitted to a video LSI in the color signal reproducing unit 3 and used for controlling the color signal reproducing unit 3 and processing the color signals.

Conventional control microcomputer 6 and color signal reproducing unit 3
Since the video / color control signal and the character display signal were separately transmitted in the signal transmission between the two, a separate signal line was required, but the signal line is common in each embodiment of the present invention. It has become. Further, in the first embodiment, since the control microcomputer 6 requires the vertical synchronization signal, the vertical synchronization signal is transmitted from the synchronous deflection unit 5 to the control microcomputer 6.

FIG. 2 shows the configuration of the video control apparatus according to the first embodiment of the present invention.

The image control apparatus of this embodiment includes a control signal generating circuit 7, a character display signal generating circuit 8, a signal multiplexing circuit 12, a signal separating circuit 13, a signal multiplexing circuit 12, and a signal separating circuit 13. , A control signal processing circuit 10, and a character display signal processing circuit 11. However, each circuit need not be a circuit as long as it achieves the same purpose.

The signal multiplexing circuit 12 and the signal separating circuit 13 operate by receiving a vertical synchronizing signal from the synchronous deflecting unit 5 in FIG. Of course, the vertical synchronization signal may be received from other parts.

FIGS. 3 and 4 show the operation of the video control apparatus according to the first embodiment of the present invention.

As shown in FIG. 3, the signal multiplexing circuit 12 and the signal separating circuit 13 switch the transmission order of the control signal and the character display signal by using a vertical synchronizing signal.
In a normal state, a character display signal is transmitted with priority, but when a vertical synchronization signal is input, a control signal is transmitted.

First, during the character display signal transmission period (1) in FIG. 4, the signal multiplexing circuit 12 in FIG.
In 3, the character display signal processing circuit 11 is selected. As a result, a character display signal is transmitted on the signal line 14. When the vertical synchronization signal generated from the color video signal by the synchronization deflecting unit 5 and the like is input to the signal multiplexing circuit 12 and the signal separation circuit 13, the control signal transmission period (2) in FIG. As shown in FIG. 3, the signal multiplexing circuit 12 selects the control signal generation circuit 7 and simultaneously the signal separation circuit 1
At 3, the control signal processing circuit 10 is selected. As a result, a control signal is transmitted on the signal line 14. Then, when the vertical synchronizing signal ends and the character display signal transmission period (3) in FIG. 4 starts, the signal multiplexing circuit 12 selects the character display signal generating circuit 8, and at the same time, the signal separation circuit 13 performs the character display signal processing. The circuit 11 is selected. Thus, the character display signal is transmitted again on the signal line 14.

Here, the character display signal is a signal for displaying characters on a television screen, and therefore requires a vertical synchronizing signal. Also, the character display signal is not transmitted while the vertical synchronization signal exists. Therefore, if the control signal is transmitted using the period in which the vertical synchronizing signal is present, the same signal line can be effectively time-divided, and the control signal and the character display signal can be transmitted on the same signal line. .

Further, since the control signal is a digital signal having a rectangular wave, noise is likely to be mixed into the video signal. However, in this embodiment, since the control signal is transmitted during the period when the video signal does not exist by the vertical synchronization signal, there is an advantage that the noise is not mixed into the video signal.

FIG. 5 shows a configuration diagram of a video control apparatus according to a second embodiment of the present invention.

The image control apparatus of this embodiment comprises a control signal generation circuit 7, a character display signal generation circuit 8, a 0-2.5V converter 15, a 2.5-5V converter 16, and a mixer 17
1.25V signal comparator 18, 3.75V signal comparator 19, signal line 14 connecting mixer 17, 1.25V signal comparator 18 and 3.75V signal comparator 19, control signal processing It comprises a circuit 10 and a character display signal processing circuit 11. However, each circuit, mixer, each converter,
Each of the comparators may be any other means for achieving the same purpose.

Next, the operation of the video control apparatus according to the present embodiment will be described.

The control signal generated by the control signal generation circuit 7 has a signal amplitude of 0-2.5
V, and the character display signal generated by the character display signal generation circuit 8 is converted by the 2.5-5 V converter 16 so that the signal amplitude becomes 2.5-5 V. The control signal and the character display signal whose amplitudes have been converted are mixed by the mixer 1
7 are multiplexed. The multiplexed signal is shown in FIG.

In the video LSI 9, the multiplexed signal is divided into a 1.25V signal comparator 18 and a 3.75V signal comparator 19.
, The control signal is taken out by the 1.25 V signal comparator 18, and the character display signal is taken out by the 3.75 V signal comparator 19.

FIG. 7 shows a configuration diagram of a video control apparatus according to the third embodiment of the present invention.

The image control apparatus of this embodiment includes a control signal generation circuit 7, a character display signal generation circuit 8, a mixer 20,
Specific signal sequence detector 21, separation circuit 22, mixer 20
And a signal line 14 connecting the specific signal string detector 21 and the separation circuit 22, a control signal processing circuit 10, and a character display signal processing circuit 11. However, each circuit, mixer, and specific signal sequence detector may be other devices as long as they achieve the same purpose.

Next, the operation of the video control apparatus according to this embodiment will be described.

The control signal generated by the control signal generation circuit 7 has a specific signal sequence for transmission start and transmission end added before and after the control signal. Then, the control signal and the character display signal to which the specific signal sequence is added are multiplexed by the mixer 20. This multiplexed signal is shown in FIG. In FIG. 8, the specific signal sequence for starting transmission is, for example, “1048”, and the specific signal sequence for ending transmission is, for example, “5963”.

In the video LSI 9, the specific signal sequence detector 2
In step 1, the specific signal sequence is detected, and the separation circuit 22 is operated. The separation circuit 22 plays the role of a switch, and the specific signal sequence detector 104 detects the specific signal sequence “104” for transmission start.
8 ", the output is switched to the control signal processing circuit 10, and the specific signal sequence" 596
When 3 ″ is detected, the output destination is the character display signal processing circuit 11.
Is switched to With this operation, the multiplexed signal is separated.

In each of the above embodiments, the video LS
If there is an LSI that requires a control signal other than I9, the control signal can be supplied to a plurality of LSIs by branching the multiplexed signal line.

[0039]

As described above, according to the present invention, the character display signal and the control signal are multiplexed and transmitted between the control microcomputer and the video LSI. And the number of wires between them is reduced. As a result, design complexity is eliminated, and the occurrence of noise can be reduced. It is particularly effective when combined with a video LSI that requires serial data transfer under microcomputer control.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a general television receiver when the present invention is implemented.

FIG. 2 is a configuration diagram of a video control device of the television receiver according to the first embodiment of the present invention.

FIG. 3 is a configuration diagram of a signal multiplexing circuit and a signal separation circuit according to the first embodiment of the present invention.

FIG. 4 is a timing chart illustrating the operation of the video control device of the television receiver according to the first embodiment.

FIG. 5 is a configuration diagram of a video control device of a television receiver according to a second embodiment of the present invention.

FIG. 6 is a waveform diagram of a multiplexed signal in the video control device of the television receiver according to the second embodiment.

FIG. 7 is a configuration diagram of a video control device of a television receiver according to a third embodiment of the present invention.

FIG. 8 is a waveform diagram of a multiplexed signal in the video control device of the television receiver according to the third embodiment.

FIG. 9 is a configuration diagram of a general television receiver.

FIG. 10 is a configuration diagram of a conventional video control device of a television receiver.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tuning part 2 Video receiving part 3 Color / signal reproducing part 4 Audio receiving part 5 Synchronous deflection part 6 Control microcomputer 7 Control signal generating circuit 8 Character display signal generating circuit 9 Video LSI 10 Control signal processing circuit 11 Character display signal processing Circuit 12 Signal multiplexing circuit 13 Signal separation circuit 14 Signal line 15 0-2.5V converter 16 2.5-5V converter 17 Mixer 18 1.25V signal comparator 19 3.75V signal comparator 20 Mixer 21 Specific signal sequence detector 22 Separation circuit

Claims (4)

[Claims] A control signal generating means for generating a control signal for controlling each part of the television receiver; a character display signal generating means for generating a character display signal for displaying characters on a screen of the television receiver; Signal multiplexing means for multiplexing the character display signal generated by the character display signal generating means and the control signal generated by the control signal generating means; and transmitting the signal multiplexed by the signal multiplexing means. A signal line that separates the multiplexed signal transmitted by the signal line into the character display signal and the control signal; and processes the control signal separated by the signal separation unit. A television comprising: a control signal processing unit; and a character display signal processing unit that processes the character display signal separated by the signal separation unit. Video control device for the receiver. 2. The signal multiplexing unit multiplexes the character display signal and the control signal using a vertical synchronization signal of a video signal, and the signal demultiplexing unit multiplexes the signal multiplexed by the signal multiplexing unit. 2. The video control device according to claim 1, wherein the video signal is separated into the character display signal and the control signal using the vertical synchronization signal. 3. The signal multiplexing means includes means for converting the amplitude of the control signal generated by the control signal generating means to a first level, and a signal display signal generating means for generating the character display signal generated by the character display signal generating means. Means for converting the amplitude to the second level, and means for multiplexing the control signal having the converted amplitude and the character display signal having the converted amplitude, wherein the signal separating means is provided by the signal multiplexing means. 2. The television according to claim 1, further comprising: means for extracting the control signal from the multiplexed signal; and means for extracting the character display signal from the signal multiplexed by the signal multiplexing means. Video control device for the receiver. 4. The control signal generating means generates a control signal to which a specific signal sequence is added, and the signal separating means detects the specific signal sequence and controls the detection signal from the detecting signal. 2. The video control device for a television receiver according to claim 1, further comprising a selection unit that selects one of a signal and a character display signal.