JP3020676B2 - Television receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television receiver capable of receiving television signals of different systems, and more particularly to a channel (program) search.

[0002]

2. Description of the Related Art Practical use of high-vision broadcasting, which is expected as next-generation television broadcasting, is imminent. Since HDTV uses broadcast satellites,
MUSE (Multiple Sub-Nyquist S) has been developed to transmit HDTV signals within the bandwidth of one broadcasting satellite channel.
Ampling Encoding) band compression is applied.

A dedicated receiver is required to receive a Hi-Vision signal (hereinafter, referred to as a MUSE signal) band-compressed by the MUSE method. Therefore, a television receiver capable of receiving the current NTSC signal and the MUSE signal has been developed.

FIG. 1 shows the above-mentioned television receiver. Television waves from satellite broadcasting are received by a BS (broadcast satellite) antenna 1 and supplied to a BS tuner 2 . Television radio waves (UHF band due to land on the radio, VH
F band) is received by the antenna 3 and supplied to the U / V tuner 4. The BS tuner 2 and the U / V tuner 4 each select a channel based on a control signal from the control unit 5. The control unit 5 is operated by the channel search local key 6 or receives a signal from the channel search remote control key 7 by the light receiving unit 8 and is operated based on the signal.

[0005] The NTSC signal obtained by the BS tuner 2 and the U / V tuner 4 is input to a switch 9, and one of the signals is switched and derived. The output of switch 9 is
The signal is input to the video demodulation circuit 10 and the audio demodulation circuit 11, and is demodulated into a video signal and an audio signal.

When the satellite broadcast is a high-definition broadcast,
The MUSE signal obtained by the BS tuner 2 is analog /
The signal is input to a digital (hereinafter, referred to as A / D) converter 12 and converted into a digital signal. The output of the A / D converter 12 is input to a video demodulation circuit 13 and an audio demodulation circuit 14, where it is demodulated into a video signal and an audio signal.

[0007] Video demodulation circuits 10 and 13, audio demodulation circuit 1
Outputs 1 and 14 are input to a video signal switching unit 15a and an audio signal switching unit 15b, respectively. Video signal switching unit 1
5a and the audio signal switching unit 15b switch any one of the signals and supply it to the video output unit 16 and the audio output unit 17.

The operation of the channel (program) search will be described below. When performing a channel (program) search, the viewer operates the local key 6 for channel search or the remote control key 7 for channel search. Based on this operation, the control unit 5 controls the BS tuner 2
/ V Tuner 4 is instructed to search for a channel (program). A channel (program) search is performed by sequentially switching channels up or down. This switching is performed by repeating the operation of outputting video and audio for a predetermined time after reproducing the synchronization signal included in the television signal. Channel (program)
The search is first performed from the U / V tuner 4 and the U / V
After one round of the channel (program) search of the tuner 4, the channel (program) search of the BS tuner 2 is performed.

[0009] The format of the synchronization signal included in the television signal is different between the MUSE signal and the NTSC signal. Therefore, the synchronization pull-in time from the reception of the MUSE signal and the NTSC signal to the reproduction of the synchronization signal is 1 s, respectively.
200 ms. The channel switching time of the channel (program) search is set to a sum of a synchronization pull-in time, a predetermined time after the synchronization pull-in time has elapsed, and a video / audio output time for outputting video / audio.

[0010]

Conventionally, the channel switching time is fixedly set based on the longer synchronization pull-in time. That is, when the MUSE signal and the NTSC signal are mixed, a common channel switching time is set based on the synchronization signal reproduction time of the MUSE signal. For this reason, if the channel (program) search is performed continuously when the MUSE signal and the NTSC signal are mixed, the channel (program) search of the NTSC signal becomes more difficult.
Video and audio are output unnecessarily.

As described above, when a common channel switching time is set in the channel (program) search of the MUSE signal and the NTSC signal, the video / audio output time becomes long in the channel (program) search of the NTSC signal, which is unnecessary. It was waiting time.

In view of the above, the present invention sets the switching time so that the video and audio output times are the same even when performing a channel (program) search for television signals having different synchronization pull-in times. (Program) An object of the present invention is to provide a television receiver capable of performing a search.

[0013]

SUMMARY OF THE INVENTION A television receiver according to the present invention receives first and second television signals including synchronization signals of different types, respectively, and receives the first and second television signals. Receiving means for performing a channel (program) search in a state of receiving one of the television signals of the first method, and a first channel (program) when the receiving means performs the channel (program) search. The set time from the reception of the program to the reception of the second channel (program) is set to be different between the first and second methods, and the difference between the synchronization pull-in times of the first and second methods is set. Switching time setting means for making the output time of the video and the audio substantially the same even if there is any.

[0014]

In the above means, when performing a channel (program) search for television signals of the first and second systems having different synchronization signals, different switching times are set. As a result, the switching time can be set so that the video and audio output times are the same even if the synchronization pull-in time is different, so that a channel (program) search without unnecessary waiting time can be performed.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows a television receiver according to the present invention. The same parts as those of the circuit shown in FIG. 1 are denoted by the same reference numerals, and different parts will be described here.

The MUSE signal converted into a digital signal by the A / D converter 12 is further input to a synchronous reproduction determination circuit 19. Similarly, the NTSC signal output from the switch 9 is also input to the synchronous reproduction determination circuit 20.

The synchronous reproduction determining circuits 19 and 20 detect that the synchronous signals included in the MUSE signal and the NTSC signal have been reproduced stably. Synchronous playback determination circuit 1
Outputs 9 and 20 are input to the control unit 5, respectively. Also, N
TSC dedicated channel or MUSE signal, NTSC
Signal mixed channel (including MUSE dedicated channel)
Is supplied.

The operation will be described below. When the channel search local key 6 or the channel search remote control key 7 is operated, the control unit 5
Channel (program) to S tuner 2 and U / V tuner 4
Instruct search. The channel (program) search is performed by sequentially raising or lowering the channel in the order of the U / V tuner 4 and the BS tuner 2, for example.

Here, the satellite broadcast is composed of a MUSE signal and an NTS signal.
When broadcasting the C signal, the BS tuner 2 changes the setting of the channel switching time according to the type of the television signal.

First, the case where a MUSE signal is received and a channel (program) search is performed will be described. In this case, the MUS from the A / D converter 12 is
An E signal is supplied. The synchronous reproduction determination circuit 19
It detects that the synchronization signal included in the USE signal has been stably reproduced, and supplies the detection result to the control unit 5. After the synchronization signal is reproduced, the control unit 5
The BS tuner 2 is instructed to output video and audio for a predetermined time.

Next, a case where a channel (program) search is performed by receiving an NTSC signal will be described. In this case, the NTSC signal from the switch 9 is supplied to the synchronous reproduction determination circuit 20. Synchronous reproduction determination circuit 20
It detects that the synchronization signal included in the signal has been reproduced stably, and supplies the detection result to the control unit 5. The control unit 5 instructs the U / V tuner to output video and audio for a predetermined time after the reproduction of the synchronization signal.

That is, different channel switching times are set for television signals having different synchronization signals so that the video and audio output times are the same even if the synchronization pull-in time is different. This allows
Unnecessary waiting time for a channel (program) search can be eliminated. The setting of the switching time is performed based on the channel information stored in the storage unit 18.

[0023]

As described above, according to the television receiver of the present invention, the switching time is set for each of the first and second television signals having different synchronization signals. Even when the synchronization pull-in time differs between the second method and the second method, the video and audio output times are the same. This enables a quick channel (program) search without unnecessary waiting time.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a conventional television receiver.

FIG. 2 is a block diagram showing a television receiver according to the present invention .
Diagram.

[Explanation of symbols]

1, 3 antenna, 2 BS tuner, 4 U / V tuner, 5 control section, 7 remote control key, 8 light receiving section, 9 switch, 10, 13 video demodulation circuit, 1
1, 14: audio demodulation circuit, 15: switching unit, 16: video output unit, 17: audio output unit, 18: storage unit, 19, 20 ...
Synchronous playback determination circuit.

Claims (2)

(57) [Claims] 1. Receiving first and second television signals including synchronization signals of different types, respectively.
A receiving means for performing a channel (program) search in a state in which one of the first and second television signals is being received; and a receiving means for performing the channel (program) search. In addition, the set time from when the first channel (program) reception is switched to the second channel (program) reception is set differently in the first and second methods, and the first and second methods are set. A television receiver comprising: switching time setting means for making the output time of video and audio substantially the same even if there is a difference in synchronization pull-in time in the system. 2. The switching time setting means includes: first and second detection means for detecting that each of the synchronization signals included in the first and second television signals has been stably reproduced. When the receiving unit is receiving the television signal of the first system, after the synchronization signal of the television signal of the first system is stably reproduced by the first detection unit, A predetermined time, a switching time of the receiving means is set so as to output video and audio, and when a television signal of the second method is received, the second detecting means detects the second method. Control means for controlling to set the switching time of the receiving means so as to output the video and audio for the predetermined time after the synchronizing signal of the television signal is stably reproduced. Claim 1 Television receiver.