JP2000050176A - Digital broadcast receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly process the change of a program to be received in the reception of a digital satellite broadcasting signal from a CS (communication satellite), etc. SOLUTION: A program to be viewed is received by a system such as a tuner 1a and a demodulating part 2a. Further, the reception system such as the tuner 1a and the demodulating part 2a performs the switching of channels while patrolling and stores program information data for every channel taken out from a demultiplexer 3b in a third memory part 7. When a program number is changed from an input part 4, the tuner 1a is set to a required channel based on the data of a first memory part 5 in which relation between the channel and the program number is previously stored by a control part 9. Further, video data, etc., of a designated program are taken out from the demultiplexer 3a based on the program information data of the third memory part 7. The taken out video is projected on a monitor 12 via an MPEG decoder 10 and an NTSC encoder 11. Thus, time from the change of the programs to the projection of the program on the monitor 12 is further shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital broadcast receiving apparatus, and more particularly, to a method of receiving a digital satellite broadcast signal from a CS (communication satellite) or the like, and more particularly to a smooth change of a received program.

[0002]

2. Description of the Related Art FIG. 4 is a main block diagram showing an example of a conventional digital broadcast receiving apparatus. Hereinafter, conventional digital broadcast reception will be described with reference to FIG. In digital broadcasting, a plurality of programs (programs) are multiplexed in one frequency band (channel). When a desired one of the multiplexed programs is received, the tuner 33 first selects a channel including the program.
On the other hand, it is known which program number is included in each channel, and the information data is included in the transmission signal of which broadcast channel. Because of this,
The relationship between the channel and the program number is fetched in advance and stored in the memory unit 32 in advance. As a result, if the number of the program desired to be viewed (received) is input from the input unit 31, the corresponding channel is identified from the memory unit 32, and the tuner 33 is set to select that channel. The signal of the channel selected by the tuner 33 is demodulated by the demodulator 34, and a multiplexed signal (also called a stream) in which a plurality of pieces of program data are multiplexed is sent to the demultiplexer 35.

The multiplex signal is used for extracting video data and the like of each program, as well as video data and audio data of each program, and includes ID data indicating each program number, Data of each ID of video and audio,
It includes program information data such as data indicating scramble / non-scramble, program guide data related to program contents, and the like. The demultiplexer 35 extracts data (video, audio, etc.) of the designated program from the multiplex signal and outputs the data. In addition, the demultiplexer 35 normally includes a descrambling function. The video data of the designated program output from the demultiplexer 35 is decompressed on the data compressed by the MPEG decoder 36, and the NTSC encoder is used based on the decompressed digital data.
At 37, it is converted to an analog video signal. The monitor 38 projects based on this analog video signal. The control unit 39
In accordance with the program designation from the input unit 31, channel setting of the tuner 33, data extraction and descrambling of the designated program in the demultiplexer 35, MPEG decoder 36
In the data decompression process.

[0004] For example, when a program number 100 belonging to channel 1 has been received and this is to be changed to a program number 104 belonging to channel 2, this program change is shown in FIG. It changes as follows. That is, when a program change is input from the input unit 31, the designated program 104 enters a reception state after the time Ta. During this time Ta, the control unit
According to 39 and the like, processing of channel selection, fetching of program information data, and fetching of video and audio data of a specified program is performed. And during this processing period, monitor
Mute the signal output (video, audio) for 38,
Distorted projection state is prevented [(A) <monitor image>]. The mute may be processed by the NTSC encoder 37 under the control of the control unit 39, for example. As described above, the period of time Ta is a no-signal state (also called blackout) in which the output of the video and audio to the monitor 38 is stopped, and is generally a period of approximately several seconds.

[0005]

As described above, in the conventional digital broadcast receiving apparatus (FIG. 4), when a program is changed, a non-signal state of about several seconds exists. This non-signal state occurs every time a program is changed to a program on a different channel, gives a viewer a sense of incongruity, and can be a factor of deteriorating the quality of the digital broadcast receiving apparatus. Therefore, it is desirable to reduce the time of this no-signal state or eliminate it apparently. The present invention has been made from such a viewpoint, and an object of the present invention is to provide a digital broadcast receiving apparatus in which the time of a no-signal state generated when a program is changed is shortened or apparently eliminated. is there.

[0006]

According to the present invention, there is provided a first memory for storing a channel and a plurality of programs belonging to the channel in association with each other, and an input for designating a program number to be received. And a channel corresponding to the specified program number and read from the first memory unit, demodulation of a signal of the selected channel, and reproduction of a program of a specified number from the demodulated signal. A first receiving unit for outputting video data and audio data, a second memory unit storing a plurality of channels to be sequentially selected in advance, and a channel based on the data of the second memory unit. Second receiving means for performing channel selection, demodulation of signals of the selected channels, and output of program information data for each channel from the demodulated signals; A third memory unit for storing program information data for each channel has the first memory portion,
A control unit that controls the input unit, the first receiving unit, the second memory unit, the second receiving unit, and the third memory unit;
When a change from the currently received program to another program is designated by the input unit, a channel is selected based on the data in the first memory unit, and the program information data in the third memory unit is selected. A digital broadcast receiving apparatus in which the control unit controls the setting of the first receiving means so as to output video data and audio data of a program of a designated number based on the above.

[0007] A plurality of channels stored in the second memory unit are all broadcast channels. Alternatively, the plurality of channels stored in the second memory unit may be a plurality of broadcast channels selected in advance from all broadcast channels.

In addition, the program information data for each channel stored in the third memory unit is updated by cycling and repeating the channel selection based on the data in the second memory unit. .

[0009] Further, a timer unit may be provided under the control unit, and the tuning may be performed at set time intervals.

A first memory unit for storing a channel and a plurality of programs belonging to the same channel in association with each other, an input unit for specifying a program number to be received, and a program specified by the input unit Channel selection corresponding to the number and read from the first memory unit;
A first receiving means for demodulating the signal of the tuned channel and outputting video data and audio data of the program of the designated number from the demodulated signal; and a program number corresponding to the program number designated by the input unit. A channel selection read from the first memory unit, demodulation of a signal of the channel selected, and output of video data and audio data of a program of a designated number from the demodulated signal. 2, a switching circuit for switching between the output from the first receiving means and the output from the second receiving means,
A control unit for controlling the first memory unit, the input unit, the first receiving unit, the second receiving unit, and the switching circuit; and one of the first receiving unit and the second receiving unit When a designation to change the currently received program to another program is given by the input unit, the control unit sends the video data and the audio data of the program of the designated number by the other receiving unit that is not currently receiving. And a digital broadcast receiving apparatus for setting and controlling the switching circuit to switch to the other receiving means.

Further, the switching of the switching circuit is performed after video data and audio data of a program of a designated number are output from the other receiving means. Alternatively, a timer unit may be provided under the control unit, and the switching circuit may be switched after a set time.

[0012]

Embodiments of the present invention will be described below with reference to the drawings based on embodiments. FIG. 1 is a main block diagram showing one embodiment of a digital broadcast receiving apparatus according to the present invention, FIG. 2 is a main block diagram showing another embodiment, and FIG. 3 is a program change for explaining FIG. 1 or FIG. FIG. In FIG. 1, 1a and 1b are tuners for selecting a channel, 2a and 2b demodulate signals of the selected channel,
Demodulators 3a and 3b for extracting a multiplex signal in which data of a plurality of programs are multiplexed, and demultiplexers 3a and 3b for extracting data (video, audio, video information data, etc.) of a specified program from the demodulated multiplex signal. In addition, this demultiplexer usually includes a descrambling function.

Reference numeral 4 designates an input unit for designating a program to be viewed (received), and reference numeral 5 designates an equivalent unit to the memory unit 32 shown in FIG. 4, which stores a relationship between each channel and the number of a program belonging to the channel. Reference numeral 1 denotes a memory unit, reference numeral 6 denotes a second memory unit for storing a cyclic range of channel switching, reference numeral 7 denotes a third memory unit for storing data of program information necessary for setting (retrieving) of a designated program for each channel, and 8 Is a timer unit, 9 is a control unit that controls the tuners 1a and 1b, demultiplexers 3a and 3b, 10 is an MPEG decoder that performs data decompression processing on compressed video data, and 11 is digital data from the MPEG decoder 10. NTSC encoder that generates an NTSC analog video signal based on
This is a monitor that displays an analog video signal from the C encoder 11. 2, the same components as those in FIG. 1 are denoted by the same reference numerals, 21 is a switching circuit for switching the outputs from the demultiplexers 3a and 3b, 22 is a timer unit, and 23 is the same as that in FIG. It is a control unit that performs switching control and the like of the switching circuit 21. Hereinafter, description will be made separately for each figure.

(1) Embodiment of FIG. 1 In FIG. 1, the system of the tuner 1a, the demodulation unit 2a and the demultiplexer 3a is for setting reception for a program to be viewed (receiving means). It is written. On the other hand, as shown in FIG. 3B, the system of the tuner 1b, the demodulation unit 2b, and the demultiplexer 3b circulates and switches channels to acquire program information data of each channel (reception). Means), hereinafter referred to as a second receiving system. Note that the contents of the multiplex signal and the program information data are the same as those described above (FIG. 4), and description thereof will be omitted. Regarding the cyclic range of the channel in the second receiving system,
Is stored in the memory unit 6. For example, all the broadcast channels may be circulated, or a plurality of channels selected in advance from all the broadcast channels may be circulated. Specifically, under the control of the control unit 9, the tuner 1b is sequentially switched based on the data in the second memory unit 6. In this case, the channel currently being received by the first receiving system may be excluded from the cyclic range. Alternatively, the tour may be performed continuously, or the timer unit 8 may be used to perform the tour at set time intervals.

The program information data obtained through the above-mentioned channel tour is stored in the third memory unit 7. The stored data is updated by the above-mentioned tour, and the latest data is stored. Now, for example, when a program number 100 belonging to channel 1 is received, and this is changed to a program number 104 belonging to channel 2 (input unit 4), this program change is performed as shown in FIG. Transition to. The reason why the channel designation operation is not required when changing the program is that the data stored in the first memory unit 5 is used as in the case of FIG. Further, as described above, the third memory unit 7 stores the latest program information data for each channel obtained by cycling through the channels of the second reception system. Therefore, the control unit 9 acquires (reads) the setting data for the channel to which the program number 104 pertaining to the change belongs from the first memory unit 5 and immediately acquires the program information data from the third memory unit 7. (Read).

The control unit 9 sets the tuner 1a to channel 2 based on the acquired channel setting data. Demodulation unit
2a demodulates the signal of channel 2 and sends a multiplexed signal in which data of a plurality of programs is multiplexed to the demultiplexer 3a. The control unit 9 outputs video and audio data of the program number 104 to the demultiplexer 3a based on the program information data. After that, MP with the same function as the conventional (Fig. 4)
Monitor 12 via EG decoder 10 and NTSC encoder 11
The video of the program number 104 is displayed on the screen. FIG. 3 described above
When the flow of (B) is compared with the conventional flow [FIG. 3 (A)], the time from the instruction to change the program until the program is displayed is reduced by the acquisition time of the program information data.
Therefore, the no-signal state is reduced from Ta to Tb (about 60 to 70).
% Reduction). This is because the program information data is previously stored in the third memory unit 7 as described above. The above is the description of FIG.

(2) Embodiment of FIG. 2 The embodiment of FIG. 2 has two equal receiving systems. As in the case of FIG. 1, the system such as the tuner 1a is defined as a first receiving system, and the system such as the tuner 1b is defined as a second receiving system. As in the previous section, for example, when the program number 100 belonging to channel 1 is received by the first receiving system, and this is changed to the program number 104 belonging to channel 2 (input section 4), the program change Changes as shown in FIG. That is, when a program change (input unit 4) is input, the control unit 23 sets the tuner 1b of the second reception system to channel 2. The setting data necessary for this setting is read from the first memory unit 5 as in the case of FIG. The signal of channel 2 is demodulated by the demodulation unit 2b, and a multiplexed signal in which data of a plurality of programs is multiplexed is sent to the demultiplexer 3b. The demultiplexer 3b extracts program information data from the multiplex signal under the control of the control unit 23.

Next, the video and audio data of the program number 104 is output from the demultiplexer 3b based on the extracted program information data. At the time of this output, a signal indicating this is sent from the demultiplexer 3b to the control unit 23. When this transmission is made, the control unit 23 switches the switching circuit 21 to the second receiving system side. Alternatively, the switching may be performed after a set time from the program change instruction using the timer unit 22. Thus, the video of the program number 104 is transmitted to the MPEG decoder 10. Same M
The operation after the PEG decoder 10 is the same as in FIG. As described above, while the video and audio of the program number 104 related to the change are taken out, the video of the program number 100 (channel 1) before the change is continuously displayed on the monitor 12,
Program number 104 changed and designated when reception setting is completed
Switch to. FIG. 3C shows this state, and as can be seen from the figure, the no-signal state can be eliminated. The time from the instruction to change the program until the program is shown takes the same time Ta as before,
Since the no-signal state at the time of changing the program is eliminated, the viewer does not feel uncomfortable.

[0019]

As described above, according to the present invention, C
In receiving a digital satellite broadcast signal from an S (communication satellite) or the like, it is possible to smoothly process a change in a received program. That is, in the conventional digital broadcast receiving apparatus, when a program is changed to another channel, a non-signal state of about several seconds exists on the monitor. This non-signal state occurs each time a program is changed to a program on a different channel, giving the viewer a sense of incongruity and deteriorating the quality of the digital broadcast receiving apparatus.
On the other hand, according to the present invention, the time of the no-signal state can be shortened or apparently eliminated, and deterioration of the quality of the receiving device can be prevented. Thus, it can be said that the present invention can contribute to the performance improvement of the digital broadcast receiving apparatus.

[Brief description of the drawings]

FIG. 1 is a main block diagram showing an embodiment of a digital broadcast receiving apparatus according to the present invention.

FIG. 2 is a main block diagram showing another embodiment of the digital broadcast receiving apparatus according to the present invention.

FIG. 3 is a flowchart of a program change for explaining FIG. 1 or FIG. 2;

FIG. 4 is a main block diagram showing an example of a conventional digital broadcast receiving apparatus.

[Explanation of symbols]

 1a, 1b, 33 Tuner 2a, 2b, 34 Demodulation unit 3a, 3b, 35 Demultiplexer 4, 31 Input unit 5, 6, 7, 32 Memory unit 8, 22 Timer unit 9, 23, 39 Control unit 10, 36 MPEG Decoder 11, 37 NTSC encoder 12, 38 Monitor 21 Switching circuit

Claims (8)

[Claims] 1. A first memory unit for storing a channel and a number of each of a plurality of programs belonging to the channel in association with each other, an input unit for specifying a program number to be received, and the specified program number And channel selection read from the first memory unit, demodulation of a signal of the channel selected, output of video data and audio data of a program of a designated number from the demodulated signal, and And a second memory unit preliminarily storing a plurality of channels to be sequentially tuned, and a channel tuned to each of the channels based on the data in the second memory unit. Second receiving means for demodulating each channel signal and outputting program information data for each channel from the demodulated signal; and a program for each output channel A third memory unit for storing information data, and control for controlling the first memory unit, the input unit, the first receiving unit, the second memory unit, the second receiving unit, and the third memory unit When a change from a currently received program to another program is designated by the input unit, a channel is selected based on the data in the first memory unit, and the third memory is selected. Digital broadcasting, wherein the control section controls the first receiving means so as to output video data and audio data of a program of a designated number based on the program information data of the section. Receiver. 2. The digital broadcast receiving apparatus according to claim 1, wherein the plurality of channels stored in the second memory unit are all broadcast channels. 3. The digital broadcast receiving apparatus according to claim 1, wherein the plurality of channels stored in the second memory unit are a plurality of broadcast channels selected in advance from all broadcast channels. . 4. The method according to claim 3, wherein the channel selection based on the data in the second memory section is repeated and repeated.
And updating the program information data for each channel stored in the memory unit.
The digital broadcast receiving device according to the above. 5. The digital broadcast receiving apparatus according to claim 4, wherein a timer unit is provided under the control unit, and the tuning is performed at set time intervals. 6. A first memory for associating and storing a channel and a number of each of a plurality of programs belonging to the same channel.
A memory unit, an input unit for specifying a program number to be received,
Channel selection corresponding to the program number specified from the input unit and read from the first memory unit, demodulation of the signal of the selected channel, and demodulation of the program of the specified number from the demodulated signal First receiving means for outputting video data and audio data, channel selection corresponding to a program number designated by the input unit and read from the first memory unit, A second receiving means for demodulating the signal of the program No. 1 and outputting the video data and the audio data of the program of the designated number from the demodulated signal; the output from the first receiving means; and the second receiving means. A switching circuit for switching between the first and second outputs; and a control unit for controlling the first memory unit, the input unit, the first receiving unit, the second receiving unit, and the switching circuit.
When a designation to change the currently received program to another program in one of the receiving means and the second receiving means is made from the input unit, the control unit causes the other receiving means which is not currently receiving the signal to be transmitted. A digital broadcast receiving apparatus which outputs video data and audio data of a program of a designated number and performs setting control to switch the switching circuit to the other receiving means. 7. The switching circuit according to claim 5, wherein switching of the switching circuit is performed after video data and audio data of a program of a designated number are output from the other receiving means. Digital broadcast receiver. 8. The digital broadcast receiving apparatus according to claim 5, wherein a timer section is provided under the control section, and the switching circuit is switched after a set time.