JP2006191267A - Digital broadcast receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital broadcast receiver capable of eliminating a feeling of incompatibility that a viewer has by eliminating the break of display of a video signal in switching a digital broadcast channel with simple constitution. <P>SOLUTION: The digital broadcast receiver comprises a main tuner 2 which receives the digital broadcast of a channel selected by a channel selection section 16, a sub-tuner 3 which performs a channel selection and receives the digital broadcast of a different channel at designated intervals of time, a broadcast data storage section 10 which stores the digital broadcast reception data of the different channel received by the sub-tuner while making it correspond to a channel number, and a video processing section 8 which normally, performs video processing of the digital broadcast reception data received by the main tuner and displays video information and which performs video processing of the digital broadcast reception data of the channel stored in the broadcast data storage section and displays video information until synchronization processing of the channel selected when switching the channel to be channel-selected and viewed by the channel selection section is completed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a digital broadcast receiving apparatus that receives a digital broadcast broadcast using a cable television transmitted using a digital broadcast radio wave or cable transmitted from a broadcast satellite or a ground station.

  As a digital broadcast receiving apparatus that receives digital broadcast signals and displays video information, for example, a main tuner unit that selects a channel that receives a video signal, a sub-tuner unit that selects a channel that decodes a text signal, A text signal sampling unit that extracts a text signal from a vertical blanking period of a signal selected by the tuner, a text signal decoding unit that decodes the extracted text signal, a text data memory unit that stores the decoded text data, A main tuner control unit that controls channel selection of the tuner unit, a sub-tuner control unit that controls channel selection of the sub-tuner unit, and a channel control unit that controls channels selected by the main tuner control unit and the sub-tuner control unit; The channel of the sub-tuner section selected by the channel control section is stored. A channel switch comprising at least an independent switching input unit that automatically switches to a channel of a text signal to be switched and an interlock switching input unit that switches a sub tuner channel selected by the channel control unit in conjunction with the main tuner unit. A circuit is known (see, for example, Patent Document 1).

  In addition, a plurality of tuner units that receive one channel by one tuner unit are provided, each tuner unit receives each program, the controller unit processes data from each tuner unit in parallel, and each tuner unit The received data is decomposed into data for each channel and recorded in a recording unit corresponding to the tuner unit, and the data stored in the recording unit is extracted by the controller unit even though it is recorded. There is known a TV program viewing apparatus that can be viewed retroactively (see, for example, Patent Document 2).

Furthermore, a first tuner for receiving a channel for normal viewing, a second tuner for receiving a channel for non-normal viewing, and a recording unit for storing received TS data for each channel are provided. The second tuner channel that has not been switched is automatically and periodically switched, and the received TS data of each channel of several channels or all channels is recorded in a predetermined recording area of the recording unit in several seconds for digital broadcasting. When the channel is switched, until the received TS data of the designated channel is decoded and displayed on the normal viewing side, the received TS data of the designated channel recorded in the recording unit is reproduced and decoded and displayed. When the decoded output display of the received TS data is probable on the normal viewing side In digital television broadcasting receiver it is known that to switch to the decode output display of the received TS data of the normal viewing side (for example, see Patent Document 3).
Japanese Patent Laid-Open No. 11-146351 (first page, FIG. 1) JP 2002-165146 A JP 2001-309255 A (first page, FIG. 1)

  However, in the conventional example described in Patent Document 1, it is possible for the user to switch and select a desired type of service from a channel desired by the user from text signals of many channels. However, when switching the channel of a digital broadcast receiver (digital television), the waiting time required to establish synchronization when signal processing of digital broadcast data received by the tuner is required. There is an unsolved problem that the display of the video signal is interrupted between the time when the switching is instructed and the time when the video signal of the corresponding channel is actually displayed, which makes the viewer feel uncomfortable.

  In the conventional example described in Patent Document 2, an arbitrary portion of recorded data can be extracted and viewed retroactively while recording data stored in a recording unit corresponding to a plurality of tuners. Although it is possible to provide a tuner unit according to the number of channels of digital broadcasting, and to provide a signal processing unit that performs signal processing by establishing synchronization of digital broadcast data received corresponding to each tuner unit, There is no waiting time at the time of switching, but there is an unsolved problem that a tuner unit and a signal processing unit corresponding to the number of digital broadcast channels are required, which is expensive and unrealistic.

  Furthermore, in the conventional example described in Patent Document 3, the digital broadcast of the channel normally viewed by the first tuner, the first demodulator, and the first TS separator is received and displayed, During this time, the channel is automatically and periodically switched by the second tuner, the second demodulator, and the second TS separator, and the received TS data of several channels or all channels is circulated to a predetermined recording area of the recording unit every several seconds. The received TS data recorded in the recording unit is supplied to the decoder for reproduction when the channel is switched by the first tuner, and the received TS data recorded in the recording unit is reproduced. It is necessary to decode with a decoder. For this purpose, the sequence header normally inserted for each GOP is analyzed to determine the parameters required for video decoding. Must set the decoder to obtain the data, there is an unsolved problem that the waiting time for this is required.

  Therefore, the present invention has been made paying attention to the above-mentioned unsolved problems of the conventional example, and the display of the video signal is not interrupted when the digital broadcast channel is switched with a simple configuration, and the viewer feels uncomfortable. It is an object of the present invention to provide a digital broadcast receiving apparatus that can eliminate the giving.

  According to a first aspect of the present invention, a digital broadcast receiving apparatus includes a channel selection unit that selects a digital broadcast channel to be selected and viewed, a main tuner that receives the digital broadcast of the channel selected by the channel selection unit, and a digital A sub-tuner that receives a broadcast and sequentially selects and receives a digital broadcast of a different channel at a time interval equal to or greater than an image reproduction start time at the time of channel switching of the digital broadcast, and a digital broadcast reception of a different channel received by the sub-tuner A broadcast data storage unit that stores a video signal separated from data in association with a channel number, and normally processes digital broadcast reception data received by the main tuner to display video information, and the channel selection unit The channel selected when switching the channel for viewing The video signal of the corresponding channel synchronization process is stored in the broadcast data storage unit until the completion by the image processing is characterized by comprising a video processor for displaying video information.

  In the first aspect of the invention, the main tuner receives the digital broadcast of the digital broadcast channel selected by the channel selection unit, and the display device displays video information obtained by processing the received digital broadcast data by the video processing unit. Then, the secondary tuner selects and receives digital broadcasts of different channels at predetermined time intervals, and sequentially stores the video signals separated from the received digital broadcast data of each channel in association with the channel numbers in the broadcast data storage unit, When a new channel is selected by the channel selection unit, the video processing unit performs video processing on the video signal of the corresponding channel stored in the broadcast data storage unit until the synchronization processing of the corresponding channel is completed. Since information is displayed, video display on the display device is reliably prevented from being interrupted when switching channels. Preparative it is, broadcast data and immediately preceding the broadcast data in the storage unit corresponding channel is stored, since this is displayed, it is possible perform channel switching without causing discomfort to the viewer.

According to a second aspect of the present invention, there is provided a digital broadcast receiving apparatus according to the first aspect, wherein the sub-tuner switches and receives digital broadcast reception data of other broadcast channels excluding the broadcast channel received by the main tuner. It is configured as described above.
In the second aspect of the invention, since the secondary tuner sequentially receives and receives the digital broadcast reception data of other broadcast channels except the broadcast channel received by the main tuner, the number of digital broadcast data stored in the broadcast data storage unit is 1 Thus, the storage capacity of the broadcast data storage unit can be reduced.

Furthermore, the digital broadcast receiving apparatus according to the third invention is characterized in that, in the first or second invention, one of the main tuner and the sub-tuner is composed of a plurality of tuners.
In the third aspect of the invention, since either one of the main tuner and the sub-tuner is constituted by a plurality of tuners, when the main tuner is constituted by a plurality of tuners, each tuner receives digital broadcasts of different channels. Thus, when a different channel is selected in the channel selection unit, when the selected channel is received by another tuner, the tuner can be selected to shorten the reception processing time of the tuner. Channel switching time can be shortened. In addition, even when the sub-tuner is composed of a plurality of tuners, when digital broadcasting is received by one tuner, reception processing can be started by another tuner, and the reception processing time at the sub-tuner is shortened. be able to.

Furthermore, in the digital broadcast receiving apparatus according to a fourth aspect of the present invention, in any one of the first to third aspects, the broadcast data storage unit uses a decoder to decode the broadcast reception data received by the sub-tuner. It is characterized by being configured to store video signals.
In the fourth aspect of the invention, the broadcast data stored in the broadcast data storage unit is stored in the broadcast data storage unit because the broadcast data received by the sub-tuner is synchronized and then decoded by the decoder. By performing video processing in the video processing unit, it can be displayed immediately as video information, and it is possible to reliably prevent display of video information from being interrupted when switching channels.

  Still further, in the digital broadcast receiving apparatus according to a fifth aspect of the present invention, in any one of the first to third aspects of the invention, the broadcast data storage unit converts the transport stream output from the sub-tuner into MPEG data. A compressed video signal output from a DEMUX circuit that separates into a certain compressed video signal, audio signal, and additional information is stored.

  In the fifth aspect of the invention, the DEMUX circuit performs TS synchronization processing on the transport stream output from the sub-tuner and demultiplexes it to separate it into a compressed video signal, audio signal and additional information. Since the compressed video signal that has already been stored can be stored and a slight waiting time is required due to the decoding time in the video processing unit, the MPEG encoded compressed data is stored, so the broadcast data storage unit Storage capacity can be reduced.

  According to a sixth aspect of the present invention, in the digital broadcast receiving apparatus according to any one of the first to fifth aspects of the invention, the broadcast data storage unit sends the digital broadcast reception data of each broadcast channel to the channel selection unit. It is characterized in that it is configured to store more than the time required to establish synchronization of broadcast reception data output from the main tuner from the time of switching the channel selection viewing channel.

  In the sixth aspect of the invention, the broadcast data storage unit requires digital broadcast reception data of each broadcast channel to establish synchronization of the broadcast reception data output from the main tuner from the time when the channel selection viewing channel is switched by the channel selection unit. Since it is stored for more than the time, the video information immediately before the sequentially selected channels can be displayed without interruption even if the channel is frequently switched.

  The digital broadcast receiver according to a seventh aspect of the present invention is the digital broadcast receiver according to any one of the first to fourth aspects, wherein the broadcast data storage unit is still image data independent of the broadcast reception data received by the secondary tuner, for example It is characterized in that it is configured to extract and store an I picture (Intra coded picture) that can compose a still image independently without using other frame information in a frame obtained by encoding an input signal as it is. Yes.

 In the seventh invention, the still image data independent of the broadcast reception data received by the sub-tuner, for example, the frame obtained by encoding the input signal as it is in the broadcast data storage unit, the still image alone is used without using other frame information. By extracting and storing an I picture (Intra coded picture) that can be configured, still image information immediately before the selected channel can be displayed when the channel is switched.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a receiving antenna that receives a digital broadcasting radio wave transmitted from a digital broadcasting station, and the digital received by this receiving antenna. Broadcast radio waves are supplied to the main digital tuner 2 and the sub digital tuner 3.

  The main digital tuner 2 is a digital tuner used for channel selection of a normal broadcast channel, in which a digital broadcast channel number and corresponding frequency data are set, and a selected channel number is input from a control circuit 14 described later. Then, digital broadcast data having a frequency corresponding to the selected channel number is extracted, and the extracted digital broadcast data is subjected to high frequency processing and demodulation processing and output to the DEMUX circuit 4 as a transport stream.

  The sub-digital tuner 3 is a digital tuner having a sequential channel selection function for sequentially switching received digital broadcast data at predetermined time intervals. Like the main digital tuner 2, the digital broadcast channel number and corresponding frequency data are set. Each time a selected channel number is input from the control circuit 14 to be described later, digital broadcast data having a frequency corresponding to the selected channel number is extracted, and the extracted digital broadcast data is subjected to high frequency processing and demodulation processing to be converted. The data is output to the DEMUX circuit 5 as a port stream.

  Each of the DEMUX circuits 4 and 5 performs a TS synchronization process on the transport streams output from the main digital tuner 2 and the sub digital tuner 3 and demultiplexes them to decompress the compressed video signal, audio signal, and selection data which are MPEG data. Separated into additional information composed of station information and program information, etc., and output the compressed video signal and audio signal, which are separated MPEG data, to the decoders 6 and 7, and additional information composed of channel selection information and program information, etc. Information is output to the control circuit 14 described later.

The decoders 6 and 7 individually decode the compressed video signals and audio signals, which are MPEG data output from the DEMUX circuits 4 and 5, and convert them into video signals and audio signals. The converted video signals and audio signals are processed by video processing. Are output to the video processing circuit 8 and the audio processing circuit 9 as a unit.
On the other hand, the video signal output from the decoder 7 is supplied to a broadcast data storage unit 10 constituted by a flash memory or the like, and when the main digital tuner 2 performs channel switching, digital broadcast data of a new broadcast channel is established synchronously. Then, the video signal of each broadcast channel set longer than the waiting time required for the decoded data to be output from the decoder 6 is sequentially overwritten and stored in a storage area formed corresponding to each broadcast channel number. Therefore, in the broadcast data storage unit 10, the digital broadcast data output from the sub-digital tuner 3 is demultiplexed by the DEMUX circuit 5 every predetermined time, and the video signal decoded by the decoder 7 is set longer than the waiting time. Overwritten and stored repeatedly for the specified time.

  Then, the video processing circuit 8 selects the image signal input from the decoder 6 when the selection signal SC supplied from the control circuit 14 has a logical value “1”, for example, and the selection signal SC has a logical value “0”. The video signal corresponding to the selected channel number read from the broadcast data storage unit 10 is selected, the selected video signal is adjusted in brightness, contrast, etc., and output to the display control unit 11 as video data. Video data is displayed on a display device 12 constituted by a liquid crystal display, a plasma display, a CRT display, or the like connected to the display control unit 11.

In the audio processing circuit 9, the audio signal input from the decoder 6 is amplified and output to the speaker 13.
On the other hand, the control circuit 14 outputs a selected channel number to be selected to the main digital tuner 2 based on a remote control signal such as a channel number selection signal and a volume adjustment signal received from the external remote controller 16 by the remote control receiving circuit 15. At the same time, the channel number is incremented, for example, every predetermined time to the sub-digital tuner 3 and the selected channel number is output, and the selection signal SC of logical value “0” is output to the video processing circuit 8 when the channel is switched. During other normal processing, a selection signal SC having a logical value “1” is output.

Here, the control circuit 14 includes, for example, a central processing unit 14a that executes at least the digital broadcast receiving process shown in FIG. 2, a ROM 14b that stores a program for processing executed by the central processing unit 14a, and a process that is executed by the central processing unit 14a. And a microcomputer 14M having a RAM 14c for storing calculation process data and calculation result data.
As shown in FIG. 2, the digital broadcast receiving process executed by the central processing unit 14a is started when the power of the digital broadcast receiving apparatus is turned on. First, in step S1, the video processing circuit 8 performs logic processing. The selection signal SC having the value “1” is output, and then the process proceeds to step S2, where it is determined whether or not the remote control receiving circuit 15 has received the channel number selection signal from the remote control 16, and the channel number selection signal is received. If not, it waits until it is received, and if it receives a channel number selection signal, it proceeds to step S3.

  In step S3, the channel number designated by the channel number selection signal is output to the main digital tuner 2, and then the process proceeds to step S4, where channel selection information and program information demultiplexed from the DEMUX circuit 4 are constituted. It is determined whether or not additional information to be input has been input. If additional information has not been input, the process waits until it is input. If additional information has been input, the process proceeds to step S5.

  In this step S5, a receivable digital broadcast channel is determined based on the channel selection information included in the additional information, and other digital broadcast channels that are currently selected by the main digital tuner 2 are excluded from the determined digital broadcast channel. For example, the digital broadcasting channels are sorted in ascending order of channel numbers, and then the process proceeds to step S6. For example, the youngest channel number is output to the sub-digital tuner 3 as the selected channel number, and then the process proceeds to step S7.

In step S7, it is determined whether or not a video signal is output from the decoder 7. If no video signal is output, the process proceeds to step S8 to determine whether or not a channel number selection signal is input from the remote controller 16. When the channel number selection signal is not input, the process returns to step S7.
If the determination result of step S7 is that the video signal is output from the decoder 7, the process proceeds to step S9, overwriting the video signal in the broadcast data storage area of the corresponding channel number formed in the broadcast data storage unit 10. Then, the process proceeds to step S10, and after a video signal is started to be stored for a predetermined time, that is, after the selected channel number is output from the control circuit 14 in the main digital tuner 2, until the video signal is output from the decoder 6. It is determined whether or not a set time has elapsed, preferably a slight extra time added to the wait time. If the set time has not elapsed, the process returns to step S9. If the set time has elapsed, step S11 is performed. In the same manner as steps S2 and S08 described above, the remote control receiving circuit 15 performs the control from the remote control 16 in the same manner. It is determined whether or not a channel number selection signal has been received. If no channel number selection signal has been received, the process proceeds to step S12 to determine whether or not there is a channel number next to the current channel number. If the next younger channel number exists, the process proceeds to step S13, and the corresponding channel number is output to the sub-digital tuner 3 as the selected channel number. Then, the process returns to step S7, and the next younger channel number does not exist. Returns to step S6.

  On the other hand, if the determination result of steps S8 and S11 is that which received the channel number selection signal from the remote controller 16, the process proceeds to step S14 to output the selected channel number to the main digital tuner 2, and then step In S15, the selection signal SC having the logical value “0” is output to the video processing circuit 8, and then in S16, the video signal of the corresponding channel number stored in the broadcast data storage unit is obtained. The data is read out and supplied to the video processing circuit 8 through the buffer circuit.

  Next, the process proceeds to step S17, where it is determined whether or not the video signal of the new channel number received by the main digital tuner 2 has been output from the decoder 6, and if no new video signal is output, the process proceeds to step S16. When a new video signal is output, the process proceeds to step S18, where the selection signal SC having the logical value “1” is output to the video processing circuit 8, and then the process returns to step S12.

Next, the operation of the first embodiment will be described.
If it is assumed that the power of the digital broadcast receiving apparatus is not turned on, power is not supplied to all the circuits including the control circuit 14, and the digital broadcast cannot be received.
In this state, when the power of the digital broadcast receiving apparatus is turned on, the power is supplied to all the circuits including the control circuit 14 to be in an operational state, and the central processing unit 14a in the microcomputer 14M of the control circuit 14 is shown in FIG. The digital broadcast reception process shown is started.

In this digital broadcast reception process, first, a selection signal SC having a logical value “1” is output to the video processing circuit 8 (step S1), whereby the analog video signal output from the decoder 6 by the video processing circuit 8 is output. It is set to select and process video.
Next, it is determined whether or not a channel number selection signal for designating a channel number is input from the remote controller 16, and when the channel number selection signal is not input, the controller waits until it is input, and the user operates the remote controller 16 to operate it. When the channel number selection signal is received by the remote control receiving circuit 15 by designating the channel number, the channel number designated by the received channel number selection signal is output to the main digital tuner 2 (step S3).

  For this reason, the main digital tuner 2 extracts the digital broadcast data of the designated channel number, frequency-processes and demodulates it, and outputs the transport stream to the DEMUX circuit 4. In this DEMUX circuit 4, TS synchronization processing is performed on the input transport stream, and then demultiplexing is performed to add a compressed video signal, compressed audio signal, channel selection information, program information, and the like as MPEG data. The information is separated, the additional information is output to the central processing unit 14a of the microcomputer 14M, and the compressed video signal and the compressed audio signal are output to the decoder 6, respectively.

The decoder 6 decodes the input compressed video signal and compressed audio signal, converts them into normal video signals and audio signals, and outputs the converted video signals and audio signals to the video processing circuit 8 and the audio processing circuit 9, respectively. .
Therefore, in the video processing circuit 8, since the selection signal SC is a logical value “1”, the video signal output from the decoder 6 is selected, and the video signal is adjusted by adjusting the brightness, contrast, etc. Is output to the display device 12 via the display control unit 11, and the video information of the corresponding channel is displayed on the display device 12.

  On the other hand, when additional information is output from the DEMUX circuit 4, a receivable digital broadcast channel is determined based on channel selection information included therein, and the determined digital broadcast channel numbers are sorted and arranged in ascending order of channel numbers. In step S5, the channel of the youngest digital broadcast channel is output to the sub-digital tuner 3 as the selected channel number.

For this reason, the sub-digital tuner 3 also starts to receive a digital broadcast channel corresponding to the selected channel number, and performs frequency processing and demodulation processing on the received digital broadcast data to output it to the DEMUX circuit 5 as a transport stream.
For this reason, the DEMUX circuit 5 performs TS synchronization processing on the transport stream and then performs demultiplexing to separate the compressed video signal, compressed audio signal, and additional information that are MPEG data into the decoder 7. It is output and converted into a normal video signal by decoding, and this video signal is stored in the storage area corresponding to the channel number of the broadcast data storage unit 10.

The storage of the video signal in the broadcast data storage unit 10 is continued for a set time, and is set to be longer than the waiting time until the video signal is output from the decoder 6 after the channel number is output to the main digital tuner 2. When the set time continues, recording of the video signal to the broadcast data storage unit 10 is stopped.
In this state, if the channel number selection signal is not input from the remote controller 16, the process proceeds from step S11 to step S12 to determine whether or not the next younger channel number exists, and then to the younger. If the channel number exists, the process proceeds to step S13, where the corresponding channel number is output to the sub-digital tuner 3 as the selected channel number, and the channel is switched.

Then, the same processing as described above is executed for the new channel number, and the normal video signal output from the decoder 7 is overwritten and stored in the storage area corresponding to the channel number of the broadcast data storage unit 10.
In this way, the video signal is stored in the broadcast data storage unit 10 while incrementing the channel number of the digital broadcast station that can be sequentially received, and when the storage of the video signal at the top channel number is completed, When the process proceeds to step S12, since the next younger channel number does not exist, the process proceeds to step S6, where the youngest channel number is output to the sub-digital tuner 3 as the selected channel number, and is output from the decoder 7 at this time. The video signal to be recorded is overwritten and stored in the storage area corresponding to the channel number of the broadcast data storage unit 10.

Therefore, all the remaining digital broadcasts except for the digital broadcast data received by the main digital tuner 2 until the channel number selection signal for channel switching is input from the remote controller 16 to the broadcast data storage unit 10. The video signal in the channel is always updated and updated.
In this state, when a desired digital broadcast channel is input by operating the remote controller 16 in order to view a digital broadcast channel different from the digital broadcast channel currently being viewed by the user, a channel number selection signal corresponding to the digital broadcast channel is displayed, for example. It is transmitted by infrared communication and received by the remote control receiving circuit 15.

When the remote control receiving circuit 15 receives the channel number selection signal in this way, the process proceeds from step S8 or S11 in the processing of FIG. 2 to step S14, and the channel number designated by the channel number selection signal is output to the main digital tuner 2. Thus, the main digital tuner 2 starts receiving digital broadcast data with a new channel number.
Next, when the selection signal SC having the logical value “0” is output to the video processing circuit 8, the video processing circuit 8 selects the video signal read from the broadcast data storage unit 10, and then the process proceeds to step S16. Thus, the video signals corresponding to the newly selected channel numbers stored in the broadcast data storage unit 10 are sequentially read out and input to the video processing circuit 8.

For this reason, the video processing circuit 8 adjusts the brightness, contrast, etc. of the video signal of the corresponding channel number before the set time × (number of receivable digital broadcast channels−1) at the maximum, and displays it as video data. 11 to the display device 12.
For this reason, the display device 12 instantaneously switches to the video information stored in the broadcast data storage unit 10 instead of the video information of the channel number so far almost simultaneously with the output of the channel number selection signal from the remote controller 16. The video display is continued without interruption of the video on the display device 12. In addition, since the displayed video is video information immediately before the channel number desired by the user, the user can visually recognize it without a sense of incongruity.

  After that, the transport stream output from the main digital tuner 2 is subjected to TS synchronization processing by the DEMUX circuit 4, and then demultiplexed to separate the compressed stream into MPEG video data, compressed audio signal, and additional information, and separated compression. The video signal and the compressed audio signal are supplied to the decoder 6 and decoded to be converted into a normal video signal and audio signal. When the video signal is output from the decoder 6, the process proceeds from step S17 to step S18 in FIG. Then, the selection signal SC having the logical value “1” is output to the video processing circuit 8, so that the analog video data obtained by adjusting the luminance, contrast, and the like on the video signal output from the decoder 6 is displayed on the display control unit. 11 and supplied to the display device 12 through the image signal read from the broadcast data storage unit 10 so far. Switched without image information is interrupted in the image information of the normalized corresponding to the new channel number from the video information, the switching of the video information without giving an uncomfortable feeling to the user in this state is performed.

Next, a second embodiment of the present invention will be described with reference to FIGS.
In the second embodiment, a compressed video signal which is MPEG data output from the DEMUX circuit 5 is stored in place of the analog video signal output from the decoder 7 as broadcast data stored in the broadcast data storage unit 10. It is a thing.
That is, in the second embodiment, as shown in FIG. 3, in the configuration of FIG. 1 in the first embodiment described above, the decoder 7 is omitted and compressed video that is MPEG data output from the DEMUX circuit 5 is used. The signal is configured to be overwritten and stored in a storage area corresponding to the channel number of the broadcast data storage unit 10, and is further stored in the decoder 6 in the compressed video signal output from the DEMUX circuit 4 and the broadcast data storage unit 10. While the compressed video signal is input, the selection signal SC output from the central processing unit 14a of the microcomputer 14M in the control circuit 14 is input to the decoder 6,
The decoder 6 selects the compressed video signal output from the DEMUX circuit 4 when the selection signal SC is a logical value “1”, and the compressed data read from the broadcast data storage unit 10 when the selection signal SC is a logical value “0”. 1 has the same configuration as that of the first embodiment described above except that it is configured to select a video signal, decode the selected compressed video signal, and convert it to a normal video signal. Corresponding parts are denoted by the same reference numerals, and detailed description thereof will be omitted.

  In response to this, as shown in FIG. 4, the digital broadcast receiving process executed by the central processing unit 14a in the microcomputer 14M of the control circuit 14 includes steps S1, S15, S18 in the process of FIG. 2 in the first embodiment. The process of S24 is changed to a process of outputting the selection signal SC to the decoder 6, and the processes of steps S7 and S17 are changed to steps S21 and S22 for determining whether or not the compressed video signal is output from the DEMUX circuit 4. The process of S9 is changed to step S23 where the compressed video signal output from the DEMUX circuit 5 is stored in the storage area corresponding to the corresponding channel number of the broadcast data storage unit 10, and the process of step S16 is further stored in the broadcast data storage unit 10. Output the compressed video signal of the corresponding channel number stored in the decoder 6 Step S24 is changed.

  According to the second embodiment, the transport stream received and processed by the main digital tuner 2 is subjected to TS synchronization processing and demultiplexing processing by the DEMUX circuit 4, thereby compressing the compressed video signal and compressed audio as MPEG data. The signal and the additional information are separated, and the compressed video signal and the compressed audio signal are supplied to the decoder 6 and decoded to be converted into the normal video signal and the audio signal, which are supplied to the video processing circuit 8 and the audio processing circuit 9. Then, while the video information is displayed on the display device 12, the channel selection viewing state in which the audio information is output from the speaker 13 can be set.

  In this channel selection viewing state, by outputting to the sub-digital tuner 3 a selected channel number that sequentially advances the digital broadcast channel at a predetermined interval, the transport stream of the digital broadcast channel that is sequentially selected is output to the DEMUX circuit 5, Separating MPEG data into a compressed video signal, a compressed audio signal, and additional information, and storing the separated compressed video signal in a storage area corresponding to the channel number of the broadcast data storage unit 10 is repeated for each digital broadcast channel. Thus, the latest compressed video signal for the set time can be stored in the broadcast data storage unit 10.

  For this reason, when the user operates the remote controller 16 to select a new channel number, the channel number selection signal is transmitted to the remote control receiving circuit 15 by infrared communication and received by the remote control receiving circuit 15. As in the first embodiment, a channel number corresponding to the channel number selection signal is output to the main digital tuner 2, and the main digital tuner 2 is switched to receive digital broadcast data having a new channel number.

  At this time, a selection signal SC having a logical value “0” is output to the decoder 6 so that the decoder 6 selects a compressed video signal read from the broadcast data storage unit 10 and decodes the compressed video signal. A new channel based on the compressed video signal stored in the broadcast data storage unit 10 is displayed on the display device 12 by converting it into a normal video signal and outputting it to the video processing circuit 8 as in the first embodiment. The previous video information by number can be displayed.

At this time, when the compressed video signal stored in the broadcast data storage unit 10 is converted into a normal video signal by the decoder 6, processing time is required. In this case, the processing time is determined by the DEMUX circuits 4 and 5. Compared with the TS synchronization processing, the time is significantly shorter, and it is possible to prevent the user from feeling uncomfortable by switching the display on the display device 12.
Moreover, in the second embodiment, the compressed video signal, which is MPEG data output from the DEMUX circuit 5, is stored in the broadcast data storage unit 10 in association with the channel number, so that the video signal indicates the compressed state. Therefore, the capacity of the compressed video signal is remarkably reduced as compared with the video signal in the first embodiment, the storage capacity of the broadcast data storage unit 10 can be greatly reduced, and an inexpensive storage medium Can be applied.

In the second embodiment, the decoder 6 and the video processing circuit 8 constitute a video processing unit.
Next, a third embodiment of the present invention will be described with reference to FIG.
In the third embodiment, the frequency of use of a user's digital broadcast channel is measured, and the number of times of storage is increased for a broadcast channel with a high use frequency.

That is, in the third embodiment, as shown in FIG. 5, the central processing unit 14a of the microcomputer 14M executes a channel usage frequency measurement process for measuring the usage frequency of each channel of digital broadcasting.
As shown in FIG. 5, this channel usage frequency measurement process is executed as a timer interrupt process at predetermined time intervals (for example, 10 msec). First, in step S31, it is determined whether or not channel switching has been performed by the remote controller 16. When the channel is switched, the process proceeds to step S32.

  In step S32, a timer value T for measuring a predetermined time (for example, about 3 minutes) after channel switching is set to a predetermined value n, and then the process proceeds to step S33 to change from the current predetermined value n to “1”. After the value decremented is set to a new predetermined value n, the process proceeds to step S34, where it is determined whether T = 0, and when T = 0, it is determined that a predetermined time has elapsed since channel switching. The process proceeds to S36, and when T> 0, it is determined that the predetermined time has not elapsed since the channel switching, the timer interruption process is terminated, and the process returns to the predetermined main program.

On the other hand, if the determination result in step S31 is not channel switching, the process proceeds to step S35, where it is determined whether T> 0, and if T> 0, the process proceeds to step S33, and T = 0. In some cases, the timer interrupt process is terminated as it is, and the process returns to a predetermined main program.
In step S36, the count value Ni of the corresponding channel (i is any one when the number of channels is 6 from a to f, for example) is incremented by "1", and the process proceeds to step S37. To do.

  In step S37, the count numbers Nb to Nf of the current viewing channel, for example, five channels excluding a are read, and the ratio of the count numbers Nb to Nf is calculated. Next, the process proceeds to step S38, and the channel selection rank of each channel is set based on the calculated ratio. At this time, when the number of channel to be selected is 5, when all of the count numbers Nb to Nf are equal, that is, when the ratios are all “1”, the channels b to f are sequentially recorded in that order. Is done. However, for example, when the ratio of the channel b is “4”, the ratio of the channel c is “3”, the ratio of the channel d is “2”, and the ratios of the channels e and f are “1”, respectively, Since the recording order is 11, the recording order is as shown in FIG. 6 such as channel b, channel c, channel d, channel b, channel c, channel e, channel b, channel c, channel d, channel b, channel f. The channel selection order is distributed so that the intervals are as even as possible with the number of times according to the ratio.

Next, the process proceeds to step S39, and channel switching control of the sub-tuner is performed according to the set channel selection order for each channel.
As described above, according to the third embodiment, when the user selects a digital broadcast channel from the time when the digital broadcast receiving apparatus is installed, when the channel is not switched for a predetermined time after that, that is, the user selects a program. When the channel switching for searching is finished, the count value Ni of the corresponding channel is incremented by “1”. Therefore, the count value Ni increases in the channel that the user often views, and the count value in the channel that the viewer often views. Ni becomes smaller.

  Therefore, as described above, when the main digital tuner 2 is currently viewing the channel a, the ratio of the count values Nb, Nc, Nd, Ne, and Nf in the remaining channels b to f is 4: 3: When 2: 1: 1, as shown in FIG. 6, the sub-digital tuner 3 selects channel b for the first time, fourth time, seventh time, and tenth time, and channel c for the second time. Channels are selected at the fifth and eighth times, channel d is selected at the third and ninth times, channel e is selected at the sixth time, and channel f is selected at the eleventh time. Then, the digital broadcast data received by the sub-digital tuner 3 is separated from the TS signal by the DEMUX circuit 5 and supplied to the decoder 7, and the normal video signal obtained by decoding the compressed video signal by the decoder 7 is supplied. Is stored in the broadcast data storage unit 10.

For this reason, the broadcast data storage unit 10 records the video signal of each channel according to the channel selection order of the sub-digital tuner 3.
Therefore, when the user is watching channel a, the frequency of switching to another channel is highest in channel b, and in this channel b, the video signal is recorded once every three times. The latest video signal among the video signals stored in the broadcast data storage unit 10 at the time of channel switching is the oldest video signal three times before, and the video signal displayed on the display device 12 when the channel is switched is displayed. A video signal close to the latest can be obtained, and a channel with a lower switching frequency is more likely to display an old video signal. For this reason, it is possible to prevent the user from feeling uncomfortable by suppressing that the old video signal is frequently displayed at the time of channel switching and the video information is shifted.

In the third embodiment, the case where the ratio is an integer has been described for the sake of simplicity. However, the present invention is not limited to this, and when the ratio is not an integer, the ratio is an integer ratio. An approximate value may be used.
In the third embodiment, the ratio is calculated and the channel selection order is set based on the ratio. However, the present invention is not limited to this, and the maximum value is selected for the most frequently selected channel. Prioritizing may be performed. For example, if there are 5 digital broadcasting channels that can be viewed, the priority order is set to 5: 4: 3: 2: 1.
Further, in the third embodiment, the case where the video signal decoded by the decoder 7 is stored in the broadcast data storage unit 10 has been described. However, the present invention is not limited to this, and the second embodiment described above is not limited thereto. Thus, the compressed video signal output from the DEMUX circuit 5 may be stored in the broadcast data storage unit 10.

  In the third embodiment, the case where the latest video signal among the video signals stored in the broadcast data storage unit 10 is processed has been described. However, the present invention is not limited to this, and the frequency of use is not limited thereto. For many channels, video information recorded a plurality of times may be continuously played back, or video information may be recorded for a plurality of times in advance for all channels in parallel, and these may be played back continuously.

  In the first to third embodiments, the case where the digital broadcast data of each digital broadcast channel stored in the broadcast data storage unit 10 is used only at the time of channel switching in the main digital tuner 2 has been described. However, the present invention is not limited to this, and a multi-screen is formed based on the stored video signal or compressed video signal, and this multi-screen is displayed on the display device 12 when the channel number is selected by the remote controller 16 to select a channel. Can also be used.

  Furthermore, in the first to second embodiments, the case where a digital broadcast channel that can be received is selected based on the additional information output from the DEMUX circuit 4 has been described. However, the present invention is not limited to this. Receivable digital broadcast channels corresponding to the area where the digital broadcast receiver is installed are stored in the storage table in advance, and the receivable digital broadcast channels are read from the storage table and set according to the installation area. Good.

Furthermore, in the first to third embodiments, the case where the receivable digital broadcast channels are sorted in order from the smallest number has been described. However, the present invention is not limited to this, and the channel number is large. You may make it sort in order, and you may make it arrange | position a channel number at random.
In the first to third embodiments, the channel number received by the main digital tuner 2 has been described as being skipped by the secondary digital tuner 3, but the present invention is not limited to this. Instead, video signals may be stored for all receivable digital broadcast channels.

  In the first to third embodiments, the case where the number of tuners is one for each of the main digital tuner 2 and the sub-digital tuner 3 has been described. However, the present invention is not limited to this. The tuner 2 is composed of a plurality of digital tuners, each digital tuner receives a different digital broadcast to speed up the reception switching process, or the sub-digital tuner 3 is composed of a plurality of digital tuners, and reception switching is performed. The processing can be speeded up, and furthermore, a plurality of sets of tuners, DEMUX circuits, and decoders can be provided to reduce the waiting time due to the TS synchronization processing.

In the first and second embodiments, the case where the remote controller 16 is applied as the channel selection unit has been described. However, the present invention is not limited to this, and a numeric keypad, a keyboard, or the like is applied as the channel selection unit. Also good.
Furthermore, in the first to third embodiments, the case of switching the digital broadcast channel has been described. However, the data broadcast data output from the DEMUX circuit 5 is stored in the broadcast data storage unit 10 and the user Is switched from the viewing state of the video broadcast data to the viewing state of the data broadcast, the screen can be quickly changed by supplying the data broadcast data stored in the broadcast data storage unit 10 to the video processing circuit 8. Also, it is possible to shift to the next screen within the data broadcast without waiting time.

It is a block diagram which shows the 1st Embodiment of this invention. It is a flowchart which shows an example of the digital broadcast reception process procedure performed with a central processing unit. It is a block diagram which shows the 2nd Embodiment of this invention. It is a flowchart which shows an example of the digital broadcast reception process procedure performed with the central processing unit in 2nd Embodiment. It is a flowchart which shows an example of the use frequency measurement process procedure performed with the central processing unit which shows the 3rd Embodiment of this invention. It is explanatory drawing which shows the channel selection order | rank of each digital broadcast channel.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Reception antenna, 2 ... Main digital tuner, 3 ... Sub digital tuner, 4, 5 ... DEMUX circuit, 6, 7 ... Decoder, 8 ... Video processing circuit, 11 ... Display control part, 12 ... Display apparatus, 14 ... Control Circuit, 14a ... Central processing unit, 14b ... ROM, 14c ... RAM, 14M ... Microcomputer, 15 ... Remote control receiving circuit, 16 ... Remote control

Claims (7)

  A channel selection unit that selects a channel of the digital broadcast to be selected and viewed; a main tuner that receives the digital broadcast of the channel selected by the channel selection unit; and at least a digital broadcast of a different channel by receiving the digital broadcast A sub-tuner that sequentially selects and receives a channel at a time interval that is equal to or greater than the image playback start time when the channel of the digital broadcast is switched, and a video signal that is separated from the digital broadcast received data of different channels received by the sub-tuner is associated with the channel number And a broadcast data storage unit that stores the digital broadcast reception data received by the main tuner, displays video information, and selects the channel that is selected when the channel selection unit switches the channel to be viewed by the channel selection unit. Until the synchronization process is completed. A video signal of a corresponding channel in the storage unit are stored in video processing digital broadcast receiving apparatus characterized by comprising a video processor for displaying video information.   2. The digital broadcast reception according to claim 1, wherein the secondary tuner is configured to switch and receive digital broadcast reception data of other broadcast channels excluding the broadcast channel received by the main tuner. apparatus.   3. The digital broadcast receiving apparatus according to claim 1, wherein either one of the main tuner and the sub tuner includes a plurality of tuners.   4. The broadcast data storage unit according to claim 1, wherein the broadcast data storage unit is configured to store a video signal obtained by decoding a broadcast reception data received by the sub-tuner by a decoder. Digital broadcast receiver.   The broadcast data storage unit is configured to store a compressed video signal output from a DEMUX circuit that separates a transport stream output from the sub-tuner into a compressed video signal that is MPEG data, an audio signal, and additional information. The digital broadcast receiver according to claim 1, wherein the digital broadcast receiver is provided.   The broadcast data storage unit stores the video signal of each broadcast channel for a time required to establish synchronization of broadcast reception data output from the main tuner from when the channel selection viewing channel is switched by the channel selection unit. 6. The digital broadcast receiving apparatus according to claim 1, wherein the digital broadcast receiving apparatus is configured.   5. The broadcast data storage unit is configured to extract and store still image data independent from broadcast reception data received by a sub-tuner. 6. Digital broadcast receiver.

Images