JP2000333088A - Digital tv receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a receiver where video noise does not appear in a screen even if a program whose video format is changed is viewed by muting the video before and after the change time of the video format, detecting that the video format is changed and releasing video muting. Detecting that the video format is changed and releasing video muting. SOLUTION: The start time and the video format of a next program are extracted from EPG information in an EPG information storage memory 71. It is checked whether the video format which is set in an output processing circuit 50 is different from the video format of the next program. When they differ, it is detected whether the switch control reservation flat of a data storage memory 72, switch control reservation time and a switch destination video format are changed or not. The video format of the video during reception is read after a program from a video decoder 40 is changed. A micro computer 70 recognizes whether the video is switched or not. When it is switched, it is switched in accordance with the video format and video muting is released.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital TV receiver for a program having a plurality of video formats of a program transmitted from a television (TV) broadcasting station.

[0002]

2. Description of the Related Art In recent years, digital broadcast programs have been increasing, and the video format is, for example, 480p, 1080i.
As described above, programs having different video scanning methods (sequential scanning and interlaced scanning) and different numbers of scanning lines are being broadcast on the same channel or different channels.

When the program being watched is switched in this way, if the video format is different as described above, it is necessary to switch the scanning itself of the video, so noise appears for a moment in the video being viewed. It was very unsightly.

To solve this problem, some TV receivers always detect the video format and mute the video when the video format of the program being watched changes. However, in this receiver, when the video decoder detects that the video format has actually changed, the video is muted, and it takes a certain amount of time to see a normal video, and when a new program is being watched. In addition, there was a problem that image noise appeared on the screen and it was also unsightly.

[0005]

As described above, the conventional digital TV receiver has a problem that when a video format of a broadcast program is changed, video noise appears on a screen and is difficult to see. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to solve the above-mentioned problems and to provide a digital TV receiver in which video noise does not appear on a screen even when watching a program whose video format has been changed.

[0006]

According to a basic feature of the present invention, a tuner for selecting a channel of a received TV signal and demodulating the received TV signal and outputting digital data is provided. There is a video decoder that decodes a video from the digital data obtained by the above, a data decoder that decodes the video format of the program to be broadcast from the digital data obtained by the tuner, and a change in the video format obtained by the data decoder. A video format change time detecting means for detecting the time of the program, a clock for obtaining the current time, and a current time obtained by the clock being before the video format change time detected by the video format change time detecting means. From the time until the video decoder Video mute means for muting the video, and video mute release means for detecting that the video format of the video obtained by the video decoder has been changed and releasing the video mute by the video mute means A digital TV receiver is provided.

Therefore, the video is muted before and after the video format change time, and the video mute is released by detecting that the video format has been changed. You can watch video without noise even when watching.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of a digital TV receiver according to this embodiment. The TV receiver includes a converter 10 for converting a TV signal received by an antenna into an intermediate frequency band (IF) signal, and an IF output from the converter 10. Receives the signal, performs channel selection and digital demodulation,
As digital data, for example, MPEG TS (Transpo
rt Stream) and a video decoder 40 for decoding video data from the digital decoder.
An audio decoder 41 for decoding audio data from the digital decoder; a data decoder 42 for decoding data such as electronic program guide (EPG) information from the digital decoder; Output processing circuit 50 for performing switching control for projecting an image, a display 60 for projecting an image based on the control, and a microcomputer (hereinafter referred to as a microcomputer) for controlling each section of the digital TV receiver.
70, an EPG storage memory 71 for storing EPG information from data decoded by the data decoder 42 under the control of the microcomputer 70, and a broadcast included in the EPG information from the EPG storage memory 71 under the control of the microcomputer 70. A data storage memory 72 for storing information relating to switching control reservation for a change in the video format of the program.

The operation of this receiver will be described with reference to the flowcharts of FIGS.

The microcomputer 70 has a built-in clock (current time timer) for counting time and detects the current time. However, the information decoded by the data decoder 42 contains the current time. Information is also included, and based on this information, the built-in clock is accurately calibrated to the second or more. That is, as shown in the flowchart of FIG. 2, after reading the current time from the data decoder 42 in step 201, the current time timer in the microcomputer 70 is reset to the current time in step 202. After that, the process 203 waits for a certain time, and the same process as described above is repeated. Therefore, it can be considered that the microcomputer 70 almost always accurately detects the current time.

On the other hand, as shown in a process 301 of FIG. 3, the EP of a channel displaying an image on the display 60 is displayed.
The G information is read from the decoder 42 and the microcomputer 70
Is stored in the EPG information storage memory 71 under the control of. Thereafter, a wait is performed for a predetermined time in a process 302, and the same operation is repeated. That is, the latest EPG information is stored in the EPG information storage memory 71 at regular time intervals. Then, as shown in the flowchart of FIG.
In process 401, the microcomputer 70 first extracts the start time and the video format of the next program from the EPG information in the EPG information storage memory 71 based on the current time of the built-in timer. Thereafter, in process 402, it is checked whether or not the video format currently set in the output processing circuit 50 is different from the video format of the next program. It is detected whether the switching control reservation flag, the switching control reservation time, and the switching destination video format of the data storage memory 72 have been changed.

If the switching destination video format and the like in the data storage memory 72 have not been changed, the data in the data storage memory 72 is changed in step 404. That is, assuming that the switching control reservation flag is turned on, the switching control reservation time is set to several seconds before the next program start time, and the next program whose video format is changed starts at 8:30, for example, 8:29:57, three seconds before that. Is the switching control reservation time. At the same time, the switching destination video format is set to the video format 480p of the next program. After that, in a process 405, a similar operation is repeated with a wait for a certain time.

If the video format of the current program and the next program is the same in process 402, or if the data for switching control has already been changed in process 403, process 4
At 05, a wait is continued for a certain time.

FIG. 5 is a flowchart showing the switching control operation in the output control circuit 50. That is, the microcomputer 70 monitors the current time with a built-in current time timer. When the current time approaches the time when the program changes, first, in a process 501, it is checked whether the switching control reservation flag on the data storage memory 72 is on. If this flag is on, it is checked in process 502 whether the switching control reservation time in the memory 72 matches the current time. If there is a match, video mute is applied in step 503. Thereafter, the video format of the video being received after the program is changed is read from the video decoder 40.

When the switching control reservation flag on the data storage memory 72 is not ON, and when the current time has not yet reached the switching control reservation time, the processing 501 and the processing 501 are performed, respectively.
At 502, the answer is No, and the process waits for a certain period of time (process 504).

On the other hand, after reading the video format being received in process 503, the microcomputer 70 checks in process 505 whether the video format of the video actually being received has really been switched. In fact, if the video format of the video has been switched, the process 506 is executed.
In this case, switching is performed in accordance with the video format, and then the video mute is released. Finally, the switching control reservation flag on the data storage memory 72 is turned off, and the process returns to the beginning.

The switching control reservation time must be before the next program start time, but if it is too short, the time during which no video is displayed will be long, but if it is too short, video noise will appear on the screen. . In general, this time may be several seconds before. In the above embodiment, the switching control reservation time is set to three seconds before the next program start time. However, the present invention is not limited to this, and usually about one second is almost sufficient.

If the time at which the video mute is released is too long, the time during which the video is not displayed becomes longer, and if it is too short, video noise appears. Usually, this time may be about several seconds.

[0019]

According to the present invention, even if a program whose video format has been changed is continuously displayed, video noise does not appear on the screen, and a clear video without video noise can always be viewed. In the present invention, since the video mute is released after confirming that the video format of the video of the next program has changed, video noise does not appear on the screen even if the video format is erroneously detected as changing. .

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a digital TV receiver according to one embodiment of the present invention.

FIG. 2 is a flowchart for explaining an operation of setting a current time of a timer in the TV receiver of FIG. 1;

3 is a flowchart for explaining an operation of storing EPG information in a memory 71 in the TV receiver of FIG.

FIG. 4 is a flowchart for explaining an operation of confirming whether a video format of a program changes in the TV receiver of FIG. 1;

FIG. 5 is a flowchart for explaining a switching control operation of an output processing circuit 50 in the TV receiver of FIG. 1;

[Explanation of symbols]

10 ... Converter, 20 ... Tuner, 40 ...
・ Video decoder, 41 ・ ・ ・ Audio decoder, data decoder, 50 ・ ・ ・ Output processing circuit, 60 ・ ・ ・ Display, 70 ・ ・ ・ Microcomputer, 71 ・ ・ ・ EP
G information storage memory, 72... Data storage memory

Claims (1)

[Claims] 1. A tuner for performing channel selection and demodulation of a received TV signal and outputting digital data, a video decoder for decoding a video from the digital data obtained by the tuner, and a digital data obtained by the tuner A data decoder that decodes a video format of a program to be broadcast from, a video format change time detecting unit that detects the time of a program having a video format change obtained by the data decoder, a clock that acquires the current time, The current time obtained by the clock is a time from before to after the video format change time detected by the video format change time detection means, video mute means for muting the video decoded by the video decoder, Obtained by the video decoder A video mute canceling means for detecting that the video format of the video being changed has been changed and canceling the video mute by the video mute means.