JP2000041197A - Television receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the image breaking time that is caused when the channels are switched and to attain the smooth switching of channels by adding a storage to a TV receiver to store the video still pictures on plural screens and displaying the stored images before broadcasted images are actually outputted on screen in a channel switching mode. SOLUTION: In a channel switching mode, the channels are switched at a demodulating part 1 and by a video decoder 2. However, these channel switching operations require their processing time and a long time is needed to output the images after the channels are switched. Thereby, a changeover SW 5 is switched to display the images by using the data stored in an image memory 3 while the images are processed for outputting at the part 1 and via the decoder 2. The different images can be displayed on every channel as long as plural images are stored. Thus, it's possible to shorten the image blank time and to perform the smooth channel changing operations.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television receiver compatible with digital broadcasting.

[0002]

2. Description of the Related Art In digital broadcasting, video is transmitted in MPEG2. Due to the mechanism of MPEG2, compared to conventional analog broadcasting, the time from the start of decoding video data to the actual output of video is reduced. Take it. Therefore, there is a problem in that video output is delayed when video is newly decoded at the time of channel switching or the like. As a conventional raster blanking circuit for analog broadcasting, a circuit described in Japanese Patent Application Laid-Open No. 57-17277 is known, but since this method is based on the analog broadcasting method, it is not possible to use digital broadcasting. In this case, no effect is obtained.

[0003]

In the case of the conventional analog broadcasting system, decoding of the video itself is performed instantaneously.
Muting the analog behavior of the circuit enabled relatively smooth channel switching and the like. However, in the case of digital broadcasting, since video decoding itself takes time, the delay in image output is long and channel switching cannot be performed smoothly. Accordingly, there has been a problem that the channel switching time is slow and it is difficult to view the television such as zapping.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a television receiver with a storage device for storing a plurality of screens of still images of a video, until a broadcast is actually output when a channel is switched. The feature is that the channel is smoothly switched by displaying the image stored in the channel.

According to the present invention, the stored still image is displayed in a state where the video at the time of channel switching is interrupted, thereby shortening the time at which the video at the time of channel switching is interrupted and achieving the effect of smooth channel switching. it can.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention relates to a method and apparatus for processing a video output when a video is interrupted at the time of channel switching in a digital broadcast compatible television receiver. This has the effect of smoothing out video breaks during video decoding at the time of channel switching and performing smooth channel switching.

According to a second aspect of the present invention, there is provided a digital broadcast compatible television receiver having a storage device for storing a plurality of screens of video still images.
By displaying the stored still image in a state in which the video at the time of channel switching is interrupted, there is an effect that the time at which the video is interrupted at the time of channel switching is reduced.

Next, the invention according to claim 3 of the present invention provides:
A digital broadcast compatible television receiver has a storage device capable of storing a plurality of screens of image data from a video decoder. The last video for each channel is stored in a still image storage area, and the video at the time of channel switching is stored. In the state where the video is interrupted, the video has the function of displaying the video seen in the last video at the channel change destination stored in the still image storage area, and has the effect of shortening the video break time when switching channels.

Next, the invention according to claim 4 of the present invention provides
A digital broadcast compatible television receiver has a storage device for storing image data from a plurality of video decoders, and stores image data by previously decoding image data of channels other than the currently viewed channel by an unused decoder. By doing so, it has the effect of shortening the time at which the video at the time of channel switching is interrupted.

(Embodiment 1) An embodiment of the present invention described in claims 1 and 2 of the present invention will be described below with reference to FIG.

FIG. 1 shows a block diagram of a television receiver according to Embodiment 1 of the present invention. In FIG. 1, a demodulation unit 1 selects a digital broadcast transponder,
It demodulates and outputs a transport stream (hereinafter, TS). The video decoder 2 selects a channel from the TS signal and decodes the video. The video signal decoded by the D / A converter 4 is D / A converted and output as an analog video signal 32.

At the time of channel switching, switching by the demodulation unit 1 and switching by the video decoder 2 are performed, but both require processing time, and it takes time from when the channel switching operation is performed to when an image is output. Therefore, while the demodulation is not performed or the image decoder 2 is performing the image output processing, the switch SW is switched to display the image using the data in the image memory 3. If a plurality of images are stored in memory, different images can be displayed for each channel.

According to such a configuration, a smooth channel change process can be performed by reducing the video blanking time.

(Embodiment 2) An embodiment of the present invention described in claims 1 and 3 of the present invention will be described below with reference to FIG.

FIG. 2 shows a block diagram of a television receiver according to a second embodiment of the present invention. In the case of FIG. 2, in addition to the configuration of the first embodiment, the configuration is such that data can be written from the video decoder 2 to the image memory 3.

The image data 33 decoded by the video decoder 2 is stored in the image memory, and the contents of the image memory are displayed by switching the switch SW while the video is interrupted. The image to be stored is arbitrary, but if the image immediately before switching the channel is stored, the channel can be switched while the image is still, so that a smooth channel change can be performed.

It is also possible to store the last image of the channel viewed in the past and display the channel to be selected in advance. According to such a configuration, a smooth channel change process can be performed by reducing the video blanking time.

(Embodiment 3) An embodiment of the present invention described in claims 1 and 4 of the present invention will be described below with reference to FIG.

FIG. 3 shows a block diagram of a television receiver according to a third embodiment of the present invention. In the case of FIG. 3, the configuration of the second embodiment is modified such that writing of the image memory to the image memory can be performed from a plurality of video decoders.

Writing can be performed on the image memory 3 from the video decoder 2 and the video decoder 7. While the output of the video decoder 2 is being input to the D / A converter 4, the other channel is circulated by the video decoder 7 and the latest image of the other channel is stored in the image memory. By displaying the stored image of the channel change destination, it is possible to quickly display channel information.

Even when the channel is changed continuously, the contents of the channel can be quickly displayed by displaying the images stored one after another. According to such a configuration, a smooth channel change process can be performed by reducing the video blanking time.

[0022]

As described above, according to the present invention, in a state where the image at the time of channel switching is interrupted,
By displaying the stored still image, the time at which the image is interrupted when the channel is switched can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram of a television receiver according to Embodiment 1 of the present invention.

FIG. 2 is a block diagram of a television receiver according to a second embodiment of the present invention.

FIG. 3 is a block diagram of a television receiver according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Demodulation part 2 Video decoder 3 Image memory 4 D / A converter 5 Switching SW 6 Demodulation part 7 Video decoder 31 Transport stream 32 Analog video signal 33 Video data 34 Video data

Claims (4)

[Claims] 1. A television receiver compatible with digital broadcasting, wherein the television receiver has a function of shortening a time during which a video is interrupted when a channel is switched. 2. A digital broadcast compatible television receiver having a storage device for storing a plurality of screens of video still images, and displaying the stored still images in a state where the video is interrupted at the time of channel switching. A television receiver characterized in that the time during which a video is interrupted when switching channels is reduced. 3. A television receiver compatible with digital broadcasting has a storage device capable of storing a plurality of screens of image data from a video decoder, storing images for each channel in a still image storage area, and switching channels. It has a function to display the video seen in the last video at the channel change destination stored in the still image storage area when the video at the time is interrupted, shortening the video break time when switching channels. Television receiver. 4. A television receiver compatible with digital broadcasting, which has a storage device for storing image data from a plurality of video decoders, and decodes image data of a channel other than the currently viewed channel by an unused decoder in advance. A television receiver characterized by shortening the time during which a picture is interrupted when a channel is switched by storing an image.