JP3631079B2 - Broadcast receiving apparatus and digital broadcasting method - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a broadcast receiving apparatus and a digital broadcasting method capable of receiving both digital broadcasting and analog broadcasting.
[0002]
[Prior art]
Digital that compresses video / audio signals using digital signal compression technology and broadcasts a stream (transport stream) of time-division multiplexed video / audio digital signals of multiple programs via a transponder (satellite repeater) There is a broadcast. On the other hand, a broadcast receiving apparatus that receives such a digital multi-channel broadcast selects one of a plurality of digital broadcast transponders received through a dedicated antenna by a tuner, and a plurality of channels included in the one transponder. One of them is selected by demultiplex processing, and the video / audio signal is output by decoding the digital signal of the selected channel.
[0003]
By the way, in digital broadcasting, when C / N (Carrier to Noise Ratio) deteriorates and the bit error rate exceeds the range where error correction is possible, video and audio are not output at all. This unviewable state continues until C / N is restored. On the other hand, analog broadcasting has the property that the reception state gradually deteriorates rather than suddenly becoming impossible to watch. Therefore, there are cases where viewing by analog broadcasting is possible even when viewing by digital broadcasting is not possible. Here, in BS (Broadcasting via Satellite) broadcasting, analog broadcasting and digital broadcasting are scheduled to be broadcast by the same cast. If broadcasting is performed by this simulcast and the receiving device is configured to receive both digital broadcasting and analog broadcasting, when it becomes difficult to receive video and audio during viewing of digital broadcasting, the user himself Therefore, it is possible to continue viewing the same program by operating the remote control device to switch to analog broadcast reception.
[0004]
[Problems to be solved by the invention]
However, some users may not know what to do when the video / audio cannot be viewed at all due to the deterioration of C / N. Some users may find the switching operation troublesome. Furthermore, when the user switches to analog broadcast reception, it may be possible to continue watching the analog broadcast even though the reception level of the digital broadcast is restored.
[0005]
In view of the above circumstances, an object of the present invention is to provide a broadcast receiving apparatus that can receive an analog broadcast of the same program when it is difficult to receive a digital broadcast without troublesome operations.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, a broadcast receiving apparatus of the present invention includes an analog broadcast receiving unit that receives an analog broadcast, a digital broadcast receiving unit that receives a digital broadcast, and a reception level detection that detects the reception level of the digital broadcast. Means, a simulcast information storage means for extracting and storing information on whether analog broadcasting and digital broadcasting are broadcasting the same program by simulcast, and a reception level is a predetermined level during simulcast digital broadcast reception Switching control means for switching to reception of simulcast analog broadcasts when the power is below the level, and power supply to the digital broadcast receiving unit other than power required for reception level detection means when switching to reception of analog broadcasts by the switching means. JP by comprising a power supply stopping means for stopping To.
[0007]
With the above configuration, when analog broadcasting and digital broadcasting are broadcasting the same program by simulcast, if the reception level falls below a predetermined level during viewing of the digital broadcasting, the analog broadcasting is automatically received. Since it is switched, the user can continuously watch the same program without troublesome operations.
[0008]
The broadcast receiving apparatus according to the invention of claim 2 is dependent on claim 1 and reads information related to simulcast stored by the information storage means when the reception level falls below a predetermined level during simulcast digital broadcast reception. And a second switching control means for switching to reception of simulcast analog broadcasting when information indicating that the same program is being broadcast is read by the reading means and the information reading means. As a result, digital broadcast reception is continued when there is no simulcast information.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 3. Here, a case where a user views a broadcasting via satellite (BS) broadcast is illustrated. FIG. 1 is a block diagram showing a broadcast receiving apparatus 30 of this embodiment capable of viewing both BS digital broadcasting and BS analog broadcasting, FIG. 2 is a flowchart showing broadcast reception switching processing, and FIG. 3 is digital broadcasting. It is explanatory drawing which shows a system.
[0011]
The antenna 1 is disposed outdoors in a predetermined direction, and receives a digital broadcast signal and an analog broadcast signal transmitted from the BS. The antenna 1 generally includes a frequency converter, and supplies a received / frequency converted signal to a tuner. If the digital BS is launched on the same track as the analog BS, one antenna 1 can be shared.
[0012]
The BS digital tuner 2 extracts a signal having a specific frequency from the high-frequency digital modulation signal including video / audio data. That is, a process of selecting one from a plurality of transponders of digital broadcasting is performed. Further, the BS digital tuner 2 includes a deinterleave circuit, an error correction circuit, and the like, thereby demodulating the selected digital modulation signal and outputting a transport stream. Furthermore, the BS digital tuner 2 performs C / N determination on the selected specific frequency and supplies the C / N determination result to the system controller 13. The C / N pass / fail judgment can be made based on, for example, an error rate in an error correction circuit.
[0013]
The demultiplexer (DEMUX) 3 separates the transport stream received from the BS digital tuner 2 into MPEG2 (Moving Picture Experts Group 2) video transport packets, audio transport packets, and PSI (Program Specific Information). The demultiplexer 3 supplies the video transport packet and the audio transport packet to the AV decoder 4, and supplies service information included in the PSI and information related to simulcast to the system controller 13. As described above, a plurality of channels are multiplexed in the transport stream, and the process for selecting an arbitrary channel from among the channels is determined based on which arbitrary channel from the PSI is included in the transport stream. It becomes possible by taking out data such as whether the packet ID is multiplexed. In addition, when the broadcasting station adopts a broadcasting method in which information regarding whether analog broadcasting and digital broadcasting are broadcasting the same program by simulcast is included in the PSI, information regarding the simulcast is also obtained from the PSI. It can be taken out. Further, information for transport stream selection (transponder selection) can also be extracted from the PSI.
[0014]
The AV decoder 4 includes a video decoder that decodes video transport packets and an audio decoder that decodes audio transport packets. The video decoder decodes the input variable length code to obtain a quantization coefficient and a motion vector, and performs inverse DCT conversion, motion compensation control based on the motion vector, and the like. The audio decoder decodes the input encoded signal to generate audio data. The video data generated by the decoding is output to the video processing circuit 5, and the audio data is output to the audio processing circuit 6.
[0015]
The video processing circuit 5 receives video data from the AV decoder 4 and performs D / A conversion to generate a video signal. The audio signal processing circuit 6 receives the audio data output from the AV decoder 4, performs D / A conversion, and generates an analog audio signal.
[0016]
The BS analog tuner 17 performs channel selection processing for selecting a signal having a frequency corresponding to the channel selected by the user, and demodulation processing for FM-demodulating the signal having the selected frequency. The video / audio processing circuit 18 performs de-emphasis processing or the like for video processing to generate a video signal, and performs PCM demodulation processing or the like for audio processing to generate an analog audio signal.
[0017]
The signal switching circuit 19 selects either the video signal based on the digital broadcast from the video processing circuit 5 or the video signal based on the analog broadcast from the video / audio processing circuit 18 and outputs the selected signal to the adder 16. Further, either an audio signal based on digital broadcasting from the audio processing circuit 6 or an audio signal based on analog broadcasting from the video / audio processing circuit 18 is selected and output. Which one is selected is determined based on a switching signal from the system controller 13. In simulcast broadcast reception, priority is given to digital broadcast reception.
[0018]
The video output circuit 7 and the audio output circuit 8 include an output resistor, an amplifier, and the like. The AV output terminal 9 is provided with an output unit (a set of left and right audio output terminals and video output terminals). A monitor 24 is connected to the AV output terminal 9. The monitor 24 includes an image receiving unit including a deflection circuit 22 and a high voltage circuit 23 that drive the cathode ray tube 21, a speaker 20, and the like.
[0019]
The OSD (On Screen Display) circuit 12 outputs bitmap data based on the character information instructed to be output from the system controller 13 to the adder 16. The adder 16 performs processing for incorporating the bitmap data into the video signal output from the signal switching circuit 19. The OSD circuit 12 realizes an EPG (Electronic Program Guide) screen display based on the service information included in the PSI received by the system controller 13, and can also display an operation guide screen and the like.
[0020]
The remote control transmitter 10 is a transmitter for sending a command to the broadcast receiving device 30. When a key (not shown) provided on the remote control transmitter 10 is operated, signal light (remote control signal) indicating a command corresponding to the key is transmitted from a light emitting unit (not shown). The remote control light receiver 11 receives the signal light, converts it into an electrical signal, and supplies it to the system controller 13.
[0021]
The system controller 13 is a controller that supports both an analog broadcast receiving function and a digital broadcast receiving function, and performs a program selection process by the user using the remote control transmitter 10 or the like. Further, the system controller 13 performs processing for storing information (program information, information regarding simulcast, etc.) separated by the demultiplexer 3 in the memory 14 and automatic reception switching processing in simulcast. In this automatic reception switching process, individual power supply / stop control for each circuit using the power controller 15 is also performed.
[0022]
The automatic reception switching process in simulcast will be described based on the flowchart of FIG. The broadcast receiving apparatus receives the digital broadcast of the channel designated by the user (step S1), and determines whether the C / N in the digital broadcast is good (step S2). If C / N is good, reception of digital broadcasting is continued. On the other hand, if the C / N is not good, information about simulcast is read from the memory 14 (step S3). If there is no information related to simulcast in the memory 14 (simal cast is not implemented), reception of digital broadcast is continued. Note that the state that C / N is not good does not indicate a state where error correction is difficult, but indicates a state where there is a high possibility that error correction will be difficult. Therefore, even if the digital broadcast continues to be received, the viewing is not disabled, but the digital broadcasting is viewed with a high possibility of being unable to view.
[0023]
If there is information on simulcast in the memory 14, the power supply control unit 15 sends a command signal to supply power to the BS analog reception function part, and controls the BS analog tuner 17 based on the simulcast information. Then, the same program is received in simulcast analog broadcasting, and a switching signal is sent to the signal switching circuit 19 to select and output the video / audio from the video / audio processing circuit 18 in the signal switching circuit 19. (Step S5, Step S6). The digital broadcast C / N determination is continued (step S7). If the C / N is not recovered, the reception of the analog broadcast is continued (step S6). Note that when analog broadcasting is received, power supply to components other than the circuit necessary for C / N determination of digital broadcasting may be stopped. When the C / N is restored, a signal is sent to the signal switching circuit 19 to cause the signal switching circuit 19 to select and output the video / audio from the video / audio processing circuits 5 and 6, and to the BS. The power supply to the analog reception function part is stopped (steps S8 and S1).
[0024]
As described above, when analog broadcasting and digital broadcasting are broadcasting the same program by simulcast, the receiving device 30 obtains information about the same program and holds this information in the memory 14. When the reception level falls below a predetermined level during viewing of digital broadcast, the reception device 30 automatically switches to reception of analog broadcast based on the information stored in the memory 14. As a result, the user can continuously view the same program without troublesome operations. Further, the receiving device 30 switches to reception of simulcast digital broadcasting when detecting reception level recovery after switching to reception of simulcast analog broadcasting. It is possible to prevent the user from continuing to watch analog broadcasting.
[0025]
In the above example, switching to simulcast analog broadcast reception was made before digital broadcast reception was disabled. However, the present invention is not limited to this, and switching to simulcast analog broadcast reception after digital broadcast reception is disabled. Also good. In addition, when switching to simulcast analog broadcast reception, the OSD circuit 12 may be used to display on the screen that it is switched to analog broadcast reception.
[0026]
FIG. 3 is an explanatory diagram showing an outline of the digital broadcasting system. A digital compression-encoded video information 41, audio information 42, data information 43, and program information (including information on whether analog broadcasting and digital broadcasting are broadcasting the same program by simulcast) 44 are a multiplexing unit 45 is multiplexed into a bit stream. This bit stream is converted into a transport stream by adding an error correction code or interleaved in the transmission encoding unit 46, digitally modulated in the modulation unit 47, and transmitted. The information regarding simulcast includes the presence / absence of simulcast and the channel number of the analog broadcast being simulcast.
[0027]
【The invention's effect】
As described above, according to the present invention, analog broadcasting of the same program can be received when it is difficult to receive digital broadcasting without troublesome operations. Further, there is an effect that it is possible to prevent the user from continuing to watch the analog broadcast even though the reception level of the digital broadcast is recovered.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a broadcast receiving apparatus according to an embodiment of the present invention.
FIG. 2 is a flowchart showing automatic reception switching processing in simulcast according to the embodiment of the present invention.
FIG. 3 is an explanatory diagram showing an outline of a digital broadcast system according to an embodiment of the present invention.
[Explanation of symbols]
2 BS digital tuner 3 Demultiplexer (DEMUX)
4 AV decoder 5 Video processing circuit 6 Audio processing circuit 12 OSD circuit 13 System controller 14 Memory 17 BS analog tuner 18 Video / audio processing circuit 19 Signal switching circuit

Claims (2)

An analog broadcast receiving unit that receives analog broadcasts, a digital broadcast receiving unit that receives digital broadcasts, reception level detection means that detects the reception level of digital broadcasts, and analog broadcasts and digital broadcasts broadcast the same program by simulcasting Switching control means for switching to reception of simulcast analog broadcasting when the reception level falls below a predetermined level during reception of simulcast digital broadcasting And power supply stop means for stopping power supply to the digital broadcast receiver other than the power required for the reception level detection means when switching to analog broadcast reception by the switching means , Broadcast receiving device. The switching means includes an information reading means for reading information on the simulcast stored by the information storage means when the reception level falls below a predetermined level during reception of simulcast digital broadcasting, and the information reading means reads the same program. 2. The broadcast receiving apparatus according to claim 1, further comprising second switching control means for switching to reception of simulcast analog broadcasting when information indicating that broadcasting is being performed.

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