JPH04248781A - High definition television receiver - Google Patents

Abstract

PURPOSE:To display other video image when no high definition television signal is inputted to a receiver for a high definition television signal. CONSTITUTION:A high definition television signal is inputted and a MUSE signal is inputted to the television receiver, and when no high definition television signal is inputted (no synchronizing signal), a synchronization detection circuit 12 detects it and a synchronizing signal outputted from a MUSE decode circuit 5 is utilized and a video image is switched to an output of a video signal generating circuit 13 and the output of the circuit 13 is fed to a high definition display device 11, from which the signal is reproduced thereby preventing no video image from being outputted.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is applicable to high-definition television (
This relates to a high-definition (high-definition) receiving device.

0002

[Prior Art] High-definition television (high-definition) is a system that aims to display detailed television images on a large wide screen to provide new appeal such as power and realism that cannot be obtained with current television broadcasting. In recent years, interest has been increasing in all countries. This high-definition television
While the current standard television system has 525 scanning lines and an aspect ratio of 4:3, it has 1125 scanning lines and an aspect ratio of 16:9.

MUSE (Multiple Su
b-Nyquist Sampling Enco
ding) system has been proposed by the Japan Broadcasting Corporation (NHK). Details of the content are given in Yuichi Ninomiya et al., "Satellite 1-channel Transmission System for High-Definition Television (MUSE)" (IEICE, Technical Report, IE 84-72.1984).

However, high-definition television will not suddenly replace the current standard television, and it is thought that both television systems will coexist. At this time, even high-definition television receivers can receive and receive images from the current standard television.
Need to play.

An example of the above-mentioned conventional high-definition television receiving apparatus will be described below with reference to the drawings.

FIG. 2 is a block diagram of a conventional high-definition television receiver. In Figure 2, 1 is a high-definition video signal (G, B, R or Y, Pb, Pr)
2 is a high-definition synchronization input terminal for inputting a high-definition synchronization signal (HD, VD), 3 is a MUSE signal input terminal for inputting a MUSE signal, 4 is a synchronization processing circuit for performing synchronization processing, and 5 is a high-definition video input terminal for inputting MUS
A MUSE decoding circuit converts the E signal into a high-definition signal, 6 is a switching circuit A that switches between the high-definition video signal and the video output signal of the MUSE decoding circuit 5, and 7 is a synchronous output of the high-definition synchronization signal and the MUSE decoding circuit 5. switching circuit B for switching signals;
15 is a selection circuit that selects the first and second high-definition signals; 8 is a switching signal generation circuit that outputs a switching signal to the switching circuits 6 and 7 based on the output of the selection circuit 15; 9 is a switching circuit of the switching circuit 6; a video amplification circuit that amplifies the video output signal; 10 is a deflection circuit that performs horizontal and vertical deflection based on the synchronized output signal of the switching circuit 7; 11;
is a high-quality display that displays the output of the video amplification circuit 9 described above.

The operation of the high-definition television receiving apparatus configured as described above will be explained below. A first high-definition video signal (G, B, R or Y, Pb, Pr) is input from a high-definition video input terminal 1 . Furthermore, a high-definition synchronization signal (HD, VD) is input from the high-definition synchronization input terminal 2 . In the synchronization processing circuit 4, a synchronization signal is inputted from the aforementioned synchronization signal input terminal 2, and a video signal is inputted from the video signal input terminal. If a synchronization signal is added to the video signal, the synchronization is separated from the video signal, and if the synchronization signal is input, it is directly transmitted to the first high-definition synchronization signal [horizontal signal (HD), vertical signal (VD)]
] is output. On the other hand, a MUSE signal is input from the MUSE signal terminal 3. In the MUSE decoding circuit 5, the above-mentioned M
The USE signal is converted into a second high-definition video signal and a second high-definition synchronization signal. The switching circuit 6 switches and outputs the aforementioned first high-definition video signal and second high-definition video signal. Similarly, the switching circuit 7 switches and outputs the aforementioned first high-definition synchronization signal and second high-definition synchronization signal. Selection circuit 1
Step 5 selects the first and second high-definition signals. The switching signal generating circuit 8 generates switching signals to the aforementioned switching circuits 6 and 7 so that the signal selected by the selection circuit 15 is outputted. The video amplification circuit 9 amplifies and outputs the video signal output from the switching circuit 6 after adjusting contrast and brightness. The deflection circuit 10 receives synchronizing signals (horizontal signals, vertical signals) output from the switching circuit 7 described above.
The horizontal and vertical deflections are then synchronized and the output of the video amplification circuit described above is displayed on the high quality display 11.

[0008]

[Problem to be Solved by the Invention] However, in the above-described configuration, if there is no high-definition video signal or high-definition synchronization signal, no video is displayed, which means that either there is no signal or the high-definition receiving device is malfunctioning. The problem was that I didn't know what to do.

The present invention aims to output a video signal even in the absence of a synchronization signal, thereby preventing no video from being displayed.

0010

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a synchronization signal detection circuit, a video signal generation circuit that generates a specific video signal for switching the synchronization signal, and a high-definition television signal. A switching circuit that switches and outputs a specific video signal is provided, and when there is no synchronization signal, a specific video signal is generated and displayed.

[0011]

[Operation] With the above-described configuration, the present invention detects the presence or absence of a synchronization signal with the synchronization signal detection circuit, and when there is no synchronization signal, switches the output of the switching circuit to the synchronization signal generated by the MUSE decoding circuit. The video signal is also switched to the output of the video signal generation circuit, and the video is displayed.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS A high-definition television receiving apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a high-definition television receiving apparatus according to an embodiment of the present invention. In FIG. 1, 1 indicates a first high-definition video signal (G, B, R
or Y, Pb, Pr), and 2 is the first high-definition synchronization signal (HD, V
D), high-definition synchronization input terminal for input, 3 is MUS
High-definition synchronization input terminal for inputting E signal, 3 is MU
4 is a synchronization processing circuit that performs synchronization processing; 5 is a MUSE decoding circuit that converts the MUSE signal into a second high-definition signal; 6 is a connection between the aforementioned high-definition video signal and MUSE decoding circuit 5; 7 is a switching circuit that switches the video output signal; 7 is a switching circuit that switches between the high-definition synchronization signal and the synchronous output signal of the MUSE decoding circuit 5; 8 is a switching signal generation circuit that outputs a switching signal to the switching circuits 6 and 7; 9 10 is a video amplification circuit that amplifies the video output signal of the switching circuit 6 described above; 10 is a deflection circuit that performs horizontal and vertical deflection according to the synchronized output signal of the switching circuit 7; 11
12 is a synchronization detection circuit that detects the presence or absence of a synchronization signal from the output of the synchronization processing circuit 4; and 13 is a video signal generation circuit that generates a specific video signal. , 14 are switching circuits 14 and 15 for switching between a high-definition video signal, the aforementioned video signal, and the output of the aforementioned video signal generation circuit 13, and 15 are first and second switching circuits.
This is a selection circuit that selects high-definition signals.

The operation of the high-definition television receiving apparatus configured as described above will be explained below with reference to FIG. The first high-definition video signal (G, B, R or Y, Pb,
Pr) is input. Further, a first high-definition synchronization signal (HD, VD) is input from the high-definition synchronization input terminal 2. A synchronization signal is input to the synchronization processing circuit 4 from the synchronization signal input terminal 2 described above, and a video signal is input from the video signal input terminal 1. If a synchronization signal is added to the video signal, the synchronization is separated from the video signal, and if a synchronization signal is input, the first high-definition synchronization signal [horizontal signal (HD), vertical signal (VD)] is output as is. do.

A MUSE signal is input from the MUSE signal terminal 3. In the MUSE decoding circuit 5, the above-mentioned MUSE
The signal is converted into a second high-definition video signal and a second high-definition synchronization signal, and the synchronization signal is always output even when there is no input signal. The switching circuit 6 is the first
The high-definition video signal and the second high-definition video signal are switched and output. Similarly, the switching circuit 7 is
The first high-definition synchronization signal and the second high-definition synchronization signal described above are switched and output. The video signal generation circuit 13 generates a specific video signal, such as an on-screen video signal.

Furthermore, the switching circuit 14 switches between the output of the switching circuit 6 and the output of the video signal generation circuit 13 and outputs the same. A selection circuit 15 selects the first and second high-definition signals. The switching signal generating circuit 8 generates switching signals to the switching circuits 6, 7, and 13 so that the signal selected by the selection circuit 15 is outputted. here,
The synchronization detection circuit 12 receives the output signal (
The presence or absence of horizontal signals and vertical signals is detected and output to the switching signal generation circuit 8.

The switching signal generation circuit 8 includes a selection circuit 15
If the first high-definition signal is selected in and there is no synchronization signal in the synchronization detection circuit 12, the switching circuit 7
The switching circuit 14 generates a switching signal so that the second synchronizing signal is selected, and the switching circuit 14 selects the output of the video signal generating circuit 13 described above.

Next, when the selection circuit 15 selects the first high-definition signal and the synchronization detection circuit 12 has a synchronization signal, the switching circuit 6 selects the first high-definition signal, and the switching circuit 7 selects the first high-definition signal. The synchronizing signal generates a switching signal such that the output of the switching circuit 6 is selected in the switching circuit 14.

Next, when the selection circuit 15 selects the MUSE signal, the switching circuit 6 selects the second high-definition signal, the switching circuit 7 selects the second synchronization signal, and the switching circuit 14 selects the output of the switching circuit 6. A switching signal is generated so that the

As described above, according to this embodiment, the synchronization signal detection circuit 12, the video signal generation circuit 13, and the switching circuit 14 are provided, and when there is no synchronization signal, the output of the video signal generation circuit 13 is selected. By generating a specific video signal, it is possible to prevent no video from being displayed or from displaying a distorted video.

[0021]

As described above, according to the present invention, by providing a synchronization signal detection circuit, a video signal generation circuit, and a switching circuit, the signal can be automatically switched and specified to the display 11 even when there is no synchronization signal. Displays the video signal of

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a high-definition television receiver according to an embodiment of the present invention.

FIG. 2 is a block diagram of a conventional high-definition television receiver.

[Explanation of symbols]

1 High-definition video input terminal 2 High-definition sync input terminal 3 MUSE signal input terminal 4 Synchronous processing circuit 5 MUSE decoding circuit 6 Switching circuit 7 Switching circuit 8 Switching signal generation circuit 9 Video amplification circuit 10 Deflection circuit 11 High quality display 12 Synchronous signal detection circuit 13 Video signal generation circuit 14 Switching circuit 15 Selection circuit

Claims (1)

[Claims] 1. A synchronization processing circuit that performs synchronization separation from a first high-definition television signal, and a MUSE decoding circuit that converts a MUSE signal into a second high-definition television signal.
A first switching circuit that switches the video signals of the first high-definition television signal and the second high-definition television signal, and a second switching circuit that switches the synchronization signal of the output of the synchronization processing circuit and the output of the MUSE decoding circuit. circuit, a video signal generation circuit that generates a specific video signal, and the first step in the future.
a third switching circuit that switches between the output of the switching circuit and the output of the video signal generation circuit, a selection circuit that selects the first and second high-definition television signals, and a synchronization signal from the output of the synchronization processing circuit. a synchronous signal detection circuit that detects the presence or absence of the synchronous signal detection circuit, and a switching signal generation circuit that generates switching signals to the first, second, and third switching circuits based on the output of the selection circuit and the output of the synchronous signal detection circuit; comprising a video signal amplification circuit that amplifies the video signal that is the output of the third switching circuit described above, and a deflection circuit that generates a deflection signal based on the synchronization signal, and selects the first high-definition television signal; And if there is no synchronization signal according to the detection signal output from the synchronization signal detection circuit, the second switching circuit for switching the synchronization signal is switched to the second high-definition television signal output from the MUSE decoding circuit, and the video signal is generated. A high-definition television receiver that projects a specific video signal output from a circuit on a high-definition display.