JP2007295255A - Broadcasting receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a broadcasting receiver which detects all broadcastings of digital broadcastings and analog broadcastings by one-time search processing without providing a plurality of central processing units (CPU) and is capable of shortening the whole channel search time. <P>SOLUTION: The broadcasting receiver has a channel search mode. In the channel search mode, synchronization of a digital signal of one channel of digital broadcastings is discriminated, and the channel is stored as a digital broadcasting channel in a memory 11 to start processing for the next channel in the case that the presence of a viewable digital broadcast signal is determined, and synchronization of an analog signal of one channel of analog broadcastings is discriminated in the case that the absence of a viewable digital broadcast signal is determined, and the channel is stored as an analog broadcasting channel in the memory to start processing for the next channel in the case that a synchronizing signal of the analog signal is detected. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a broadcast receiving apparatus, and more particularly to a broadcast receiving apparatus capable of receiving both digital broadcasting and analog broadcasting.

  A digital broadcast receiving apparatus that receives a digital broadcast using a satellite or a terrestrial wave selects an arbitrary broadcast wave from a plurality of broadcast waves received through a satellite antenna or a terrestrial antenna by a digital tuner, and selects the selected broadcast wave. An arbitrary channel is further selected from among a plurality of channels included in the wave by demultiplex processing. The digital broadcast receiving apparatus extracts the digital signal of the selected channel and decodes it to output a video / audio signal. Such a digital tuner that receives digital television broadcasts can be combined with a conventional analog tuner that receives analog broadcasts to form a digital / analog broadcast receiving apparatus.

  In this type of digital / analog broadcast receiving apparatus, a channel search process for a plurality of stations is performed as a technique for efficiently searching for a channel search process on the digital tuner side and a channel search process on the analog tuner side in the following manner. There is such a conventional example.

  The second channel search that acquires the information of the digital broadcast channel by estimating the existence of the digital broadcast channel as well as the detection of the analog broadcast channel by one search process of the first channel search using the analog broadcast tuner. Describes a technique in which the number of physical channels to be searched is narrowed down to the previously estimated channels, and the entire channel search is completed in a short time.

  As an explanatory diagram of the prior art, FIG. 5 shows a flow of a first channel search for acquiring an analog broadcast channel, and FIG. 6 shows a flow of a second channel search for acquiring information of a digital broadcast channel.

  In the conventional first channel search, as shown in FIG. 5, when an analog broadcast signal is received, an initial channel search is started to determine the presence or absence of the analog broadcast signal. To detect. When there is a synchronization signal, it is stored in the memory as an analog broadcast channel, and when there is no synchronization signal, it is stored in the memory as a digital broadcast channel. When the search channel is the highest channel, the channel selection search process is terminated, and when the search channel is not the highest channel, the channel is shifted to the next channel.

In the conventional second channel search, as shown in FIG. 6, when a broadcast signal is received, a simple channel search is started, and digital broadcast information is acquired after channel selection that has been stored. When there is a change in the transmission program, the memory is updated to determine whether it is the highest channel that has been stored. If the search channel is the highest channel, the channel search is terminated, and the search channel is not the highest channel. Sometimes it shifts to the next channel (see, for example, Patent Document 1).
JP 2005-117094 A

  However, since the analog broadcast signal is detected by the first channel search and the digital broadcast signal is detected by the second channel search as in the above-described digital / analog broadcast receiving apparatus, two search processes are necessarily required. Become. Furthermore, when a digital broadcast station is newly added after the first channel search, the new digital broadcast station cannot be detected by the second channel search. In addition, in the future, since digital broadcasting becomes more widespread and analog broadcasting ends, a method of detecting digital broadcasting with priority over analog broadcasting is desirable.

  The present invention has been made in view of such circumstances, and detects all broadcasts of digital broadcasts and analog broadcasts in one search process without providing a plurality of central processing units (CPUs). An object of the present invention is to provide a broadcast receiving apparatus that can shorten the channel search time.

  The present invention provides means for solving these problems, and each invention constitutes the following technical means. That is, in order to solve the above-mentioned problem, the first invention includes a digital broadcast receiving means, an analog broadcast receiving means, a channel selecting means for selecting a channel of a digital broadcast and an analog broadcast band sequentially, and a selection. An information acquisition means for acquiring presence / absence information of an auto gain controller signal and a synchronization signal for the signal of the channel, and a reception signal quality detection means for detecting the quality of the signal received by the digital broadcast reception means, The digital signal synchronization determination of one channel of the digital broadcast is performed, and when it is determined that there is a digital broadcast signal that can be viewed, the digital broadcast channel is stored in the memory and proceeds to the next channel. If there is no signal that can be viewed as one of the analog broadcasts, Perform synchronization determination of items, if synchronization signal of an analog signal is detected and having a channel search mode traveling stored in the memory as an analog broadcast channel to the processing of the next of said channel.

  Further, according to a second aspect, in the broadcast receiving apparatus according to the first aspect, in the channel search mode, a first mode for performing a channel search for only the digital broadcast signal and a channel search for the analog broadcast signal only are performed. Mode selection means having a second mode and a third mode for performing channel search of both the digital broadcast and the analog broadcast signal, and the user selects which mode of the three modes is to be used for channel search. It was characterized by comprising.

  According to a third aspect of the present invention, there is provided a digital broadcast receiving means, an analog broadcast receiving means, a channel selecting means for sequentially selecting a channel of a digital broadcast and an analog broadcast band, and an auto for a signal of the selected channel. An information acquisition means for acquiring presence information of a gain controller signal and a synchronization signal; and a received signal quality detection means for detecting the quality of the signal received by the digital broadcast receiving means, and one channel of the digital broadcast When the digital signal is detected, the control level of the auto gain controller is detected, the presence / absence of any signal is detected, the synchronization is determined, and if it is determined that the digital broadcast signal that can be viewed is present, the digital broadcast channel is Store in memory and go to next channel, no signal available for viewing as digital broadcast If it is determined, and if it is determined that there is any signal according to the control level of the auto gain controller, the synchronization determination of one of the analog broadcasts is performed, and if a synchronization signal is detected, the analog broadcast is detected. It has a channel search mode in which it is stored in the memory as a channel and proceeds to the processing of the next channel.

  According to a fourth aspect of the present invention, in the broadcast receiver of the third aspect of the invention, a first mode for performing a channel search for only the digital broadcast signal and a channel search for the analog broadcast signal only in the channel search mode. A mode selection in which the user selects a second mode and a third mode in which channel search of both the digital broadcast and the analog broadcast signal is performed, and in which of the three modes the channel search is performed; Means.

  The following effects are brought about by the present invention. That is, when performing a channel search for digital broadcasting and analog broadcasting, first the digital broadcasting channel is detected at one frequency, then the analog broadcasting channel is detected, and then the processing proceeds to the next frequency. Without providing a plurality of devices (CPUs), it is possible to detect all digital broadcasts and analog broadcasts in a single channel search process, and further reduce the overall channel search time. Further, all broadcasts of digital broadcasts and analog broadcasts can be detected by one channel search.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. A preferred embodiment of the broadcast receiving apparatus of the present invention will be described below with reference to FIGS. FIG. 1 is a block diagram showing an example of the configuration of the broadcast receiving apparatus according to the first embodiment of the present invention.

  The broadcast receiving apparatus shown in FIG. 1 includes a remote controller (hereinafter referred to as “remote controller”) 13, an antenna 102, and a receiver 103. The receiver 103 includes digital broadcast receiving means, analog broadcast receiving means, and the like.

  As shown in FIG. 1, the analog broadcast receiving means includes an analog tuner unit 20, a video / audio IF circuit 21, a video / audio detection circuit 22, and an AGC circuit 23. The digital broadcast receiving means includes a digital tuner unit 1, a demodulation circuit 2, an error correction unit 3, a transport DEMUX (demultiplexer) 4, an MPEG decoder 5, an OSD display unit 7, a video encoder 8, and an audio. It has DAC9.

  The antenna 102 is connected to the analog tuner unit 20 and the digital tuner unit 1 of the receiver 103, and the received signal 210 from the antenna 102 is divided into two and input to the analog tuner unit 20 and the digital tuner unit 1.

  The analog tuner unit 20 selects an RF (high frequency signal) from the antenna 102 and converts it to an intermediate frequency (IF). Although not shown, the analog tuner unit 20 includes a first-stage amplifier that amplifies the received RF signal, an AGC amplifier that makes the gain variable by an external control voltage, and a local frequency that is generated by a voltage-controlled oscillator. A mixer that generates an IF signal that is a difference frequency from the received RF signal, and a PLL circuit that controls the voltage-controlled oscillator to a predetermined constant frequency output state based on channel selection data supplied from a CPU (central processing unit) 6 . Although not shown, the video / audio IF circuit 21 includes an intermediate frequency amplifier and various trap circuits. The video / audio IF circuit 21 has a necessary band from the intermediate frequency signal output from the analog tuner unit 20. Is amplified with high gain. The video / audio detection circuit 22 detects the intermediate frequency video signal amplified by the video / audio IF circuit 21 to extract a color television signal (luminance signal, color signal, synchronization signal) and detects the intermediate frequency audio signal. The analog video / audio output 230 is output. The AGC circuit 23 detects the video signal level signal from the video / audio detection circuit 22 and applies an AGC voltage value (amplification degree setting value) to the amplifier of the video / audio IF circuit 21 so that the video signal level signal is constant. give.

  On the other hand, the digital broadcast wave received by the antenna 102 is input to the digital tuner unit 1 that selects a predetermined channel, and demodulated to baseband by the demodulation circuit 2. Then, after error correction unit 3 corrects the data error, transport data DEMUX 4 separates the video data and audio data from the bit stream. The separated video data and audio data are decoded by the MPEG decoder 5. The decoded video data is converted into a standard television format by the video encoder 8 and output as a digital video output. On the other hand, the audio data is output as an analog audio signal through the audio DAC 9. The CPU 6 controls the overall operation of the receiver 103. The OSD display unit 7 superimposes or switches various types of additional data on the video data according to instructions from the CPU 6. The CPU 6 is a channel tuning unit that gives a command to the digital tuner unit 1 to sequentially tune digital and analog broadcast band channels.

  The digital tuner 1 and the demodulation circuit 2 detect the control level of an auto gain controller (AGC) existing inside, and detect the presence or absence of any signal to make a synchronization determination. For this reason, the digital tuner unit 1 and the demodulation circuit 2 are also information acquisition means for acquiring presence / absence information of an auto gain controller signal and a synchronization signal for the selected digital broadcast channel signal.

  Further, the reception state detection unit 10 detects the reception state of the channel selected by the digital tuner unit 1 from the error correction unit 3 and sends a control signal 420 to the CPU 6. The reception state detection unit 10 is reception signal quality detection means for detecting the quality of the signal received by the digital broadcast reception means. As described above, the reception state detection unit 10 sends the control signal indicating the reception state of the channel selected by the digital tuner unit 1 to the CPU 6 because the CPU 6 receives the received radio wave of the channel of the received digital broadcast. This is for monitoring the change in the state of the above, and thus the change in the reception state of the channel of the selected digital broadcast, to determine whether or not reception is possible. The reception state detection unit 10 detects the reception state by detecting the bit error rate (BER) by the error correction unit 3 and when the bit error rate exceeds a predetermined value, the digital tuner unit 1 It is determined that the channel selected in (1) cannot be received. Alternatively, when the carrier-to-noise ratio (C / N) is calculated and the carrier-to-noise ratio (C / N) becomes smaller than a predetermined value, the channel selected by the digital tuner unit 1 cannot be received. It is also possible to judge.

  The remote controller 13 is provided with a channel search start button for starting a broadcast channel search. Alternatively, the user can perform an operation for performing a channel search on a menu screen as shown in FIG.

  Next, as a first embodiment of the present invention, a channel search operation procedure will be described with reference to FIGS. FIG. 2 is a flow showing a procedure of channel search. The receiver 103 starts the channel search when the user presses the channel search start button of the remote controller 13 of FIG. 1 or performs an operation for performing a channel search on the menu screen.

  When the user starts a channel search, the digital tuner unit 1 selects the frequency of the first channel and determines whether there is a digital broadcast signal that can be viewed (step S1). In the process of determining whether or not there is a viewable digital broadcast signal, if a synchronization signal of a digital signal of a certain digital broadcast channel is detected, the CPU 6 causes the reception state detection unit 10 to detect the reception state, and the CPU 6 Determines whether the digital broadcast signal is of a viewable quality. If it is determined that viewing is possible, the digital broadcast signal is stored in the memory 11 as a digital broadcast channel (step S3).

  On the other hand, if the synchronization signal of a digital signal of a certain broadcast channel is detected but the quality is not enough to withstand viewing, or if the synchronization signal of the digital signal of a certain channel cannot be obtained, it is assumed that there is no digital broadcast signal The analog tuner unit 20 selects the frequency of the digital broadcast channel and confirms the presence / absence of the synchronization signal, whereby the CPU 6 determines the presence / absence of the analog broadcast signal (step S2).

  If there is an analog broadcast signal in the broadcast channel, the analog broadcast signal is stored in the memory 11 of FIG. 1 as an analog broadcast channel (step S4). Next, the CPU 6 determines whether or not the broadcast channel selected in the broadcast channel search is the highest channel, that is, determines whether or not to end the broadcast channel search (step S5), and the frequency not yet selected. Is present, the program shifts to the next broadcast channel (step S6), and the same processing from step S11 to step S16 is repeated.

  As described above, the CPU 6 can detect the digital broadcast and the analog broadcast in one channel search in order to determine the synchronization of the analog signal after performing the synchronization determination of the digital signal of a certain broadcast channel. That is, by using only one CPU 6, it is possible to detect all digital broadcasts and analog broadcasts by a single broadcast search process. In addition, regarding the frequency at which a broadcast channel that can be viewed as a digital broadcast exists, the search time in the entire channel search can be shortened by no longer performing analog broadcast synchronization determination.

  Under the channel search mode performed by the receiver 103, a first channel mode for searching only digital broadcast signals, a second channel mode for searching only analog broadcast signals, and a search for both digital broadcast and analog broadcast signals are performed. A total of three modes in the third mode are possible. The channel search only for digital broadcasting and the channel search only for analog broadcasting are the same as conventional channel searches.

  In the embodiment of the present invention, a channel search setting item is provided on the menu screen in order to allow the user to select which of the three modes is used for channel search. A display example of the menu screen is shown in FIG. The menu screen shown in FIG. 3 has a digital broadcast / analog broadcast search item, which is a channel search setting item, a digital broadcast only search item, and an analog broadcast only item. FIG. 3 shows an example in which a mode for performing channel search for both digital broadcasting and analog broadcasting is selected so that a marker is displayed in the item of channel search setting. In this menu, one of the three channel search modes can be selected.

  By providing these three channel search mode selection means, users who are watching only analog broadcasts or when channel search for analog broadcasts is no longer required, wasteful processing is saved, and channel search time is reduced. Can be shortened.

  Next, a second embodiment of the present invention will be described with reference to FIG. 4 and FIG. FIG. 4 is a flowchart for explaining the second embodiment. In the second embodiment shown in FIG. 4, a broadcast channel search is started by a user operation, as in the first embodiment shown in FIGS.

  The digital tuner unit 1 selects a digital broadcast frequency of the first broadcast channel and determines whether there is a viewable digital broadcast signal (step S11). When detecting a digital signal, the control level of an auto gain controller (AGC) existing in the digital tuner unit 1 and the demodulation circuit 2 is detected, and the presence / absence of any signal is detected to determine synchronization.

  When the synchronization is detected, the CPU 6 detects the reception state by the reception state detection unit 10 in FIG. 1, and the CPU 6 in FIG. 1 determines whether the digital broadcast signal is of a viewable quality. If it is determined that viewing is possible, the digital broadcast signal is stored in the memory 11 as a digital broadcast channel (step S14).

  On the other hand, if the quality is not enough to withstand viewing even if a synchronization signal can be obtained, or if the synchronization signal cannot be obtained, it is assumed that there is no digital broadcast signal and exists in the digital tuner unit 1 and the demodulation circuit 2. The amplification factor of the auto gain controller (AGC) to be checked is confirmed (step S12). If the AGC amplification factor is smaller than the predetermined value in step S12, it is considered that there is some signal in this frequency band, so the process proceeds to the analog broadcast signal synchronization determination process in step S13.

  On the other hand, if the AGC gain becomes equal to or higher than the predetermined value in step S12, it is considered that there is no signal that can be received in this frequency band, and thus this channel search is terminated.

  In the analog broadcast synchronization determination process, the analog tuner unit 20 selects the frequency of this channel and confirms the presence or absence of synchronization by determining the presence or absence of synchronization (step S13). If there is an analog broadcast signal in step S13, it is stored in the memory 11 as an analog broadcast channel (step S15).

  Next, it is determined whether or not the channel being searched for is the highest channel, that is, whether or not to end the channel search (step S16). If there is a frequency that has not been selected yet, the next broadcast is determined. Shifting to the channel (step S17), the same processing from step S11 to step S16 is repeated.

  As described above, after performing the digital synchronization determination, the analog synchronization determination is performed through the determination of whether or not the analog broadcast wave exists based on the AGC amplification factor. There is no need to perform synchronization determination processing, and the overall channel search time can be further shortened compared to the case of the first embodiment.

  Also in the second embodiment of the present invention described above, in the broadcast channel search mode, the first mode for performing channel search only for digital broadcast signals, the second mode for performing channel search only for analog broadcast signals, and digital broadcast In addition, a total of three modes can be selected from the third mode in which channel search of both analog broadcast signals and analog broadcast signals is performed.

  As shown in FIG. 3, a channel search setting item is provided in the menu so that the user can select in which mode the channel search is performed. In this way, when a user who is viewing only analog broadcasts or when a channel search for analog broadcasts is no longer necessary, wasteful processing can be omitted and channel search time can be shortened.

  Although the present invention has been described in the above examples, the present invention is not limited to the above-described embodiments, and various modifications can be employed without departing from the scope of the claims.

It is a functional block diagram which shows one Embodiment of the broadcast receiver of this invention. It is a flowchart explaining one Embodiment of the broadcast receiver of this invention. It is a figure which shows one Embodiment of the broadcast receiver of this invention. It is a flowchart explaining one Embodiment of the broadcast receiver of this invention. It is a flowchart of the 1st channel search which acquires the analog broadcast channel in a prior art. It is a flowchart of the 2nd channel search which acquires the digital broadcasting channel in a prior art.

Explanation of symbols

1 Digital tuner section (information acquisition means)
2 Demodulation circuit (information acquisition means)
3 Error correction unit 4 Transport DEMUX
5 MPEG decoder 6 CPU (received signal quality detection means)
7 0SD display section 8 Video encoder 9 Audio decoder 10 Reception state detection section (received signal quality detection means)
11 Memory 13 Remote Control 20 Analog Tuner 21 Video / Audio IF Circuit 22 Video / Audio Detection Circuit 23 AGC Circuit 102 Antenna

Claims (4)

Digital broadcast receiving means, analog broadcast receiving means, channel selection means for sequentially selecting channels of digital broadcast and analog broadcast bands, presence / absence of auto gain controller signal and synchronization signal for selected channel signals Comprising information acquisition means for acquiring information and reception signal quality detection means for detecting the quality of the signal received by the digital broadcast reception means;
The digital signal synchronization determination of one channel of the digital broadcast is performed, and when it is determined that there is a digital broadcast signal that can be viewed, the digital broadcast channel is stored in a memory and proceeds to the next channel, while the digital broadcast signal is When it is determined that there is no signal that can be viewed as broadcast, the synchronization determination of one analog signal of the analog broadcast is performed, and when the analog signal synchronization signal is detected, the analog broadcast channel is stored in the memory. And a channel search mode for proceeding to processing of the next channel.   Under the channel search mode, a first mode for performing a channel search for only the digital broadcast signal, a second mode for performing a channel search for only the analog broadcast signal, and channels for both the digital broadcast signal and the analog broadcast signal. The broadcast receiving apparatus according to claim 1, further comprising a selection unit that has a third mode for performing a search, and in which the user selects a mode in which the channel search is performed among the three modes. Digital broadcast receiving means, analog broadcast receiving means, channel selection means for sequentially selecting channels of digital broadcast and analog broadcast bands, presence / absence of auto gain controller signal and synchronization signal for selected channel signals Comprising information acquisition means for acquiring information and reception signal quality detection means for detecting the quality of the signal received by the digital broadcast reception means;
When detecting the digital signal of one channel of the digital broadcast, the control level of the auto gain controller is detected, the presence or absence of any signal is detected, the synchronization is determined, and it is determined that there is a viewable digital broadcast signal If it is determined that the digital broadcast channel is stored in the memory and proceeds to the next channel, it is determined that there is no signal that can be viewed as the digital broadcast, and it is determined that there is any signal depending on the control level of the auto gain controller. A channel search mode that performs synchronization determination of one analog signal in the analog broadcast and stores the analog broadcast channel in the memory as the analog broadcast channel and proceeds to processing of the next channel. A broadcast receiver characterized by that.   Under the channel search mode, a first mode for performing a channel search for only the digital broadcast signal, a second mode for performing a channel search for only the analog broadcast signal, and a channel search for both the digital broadcast signal and the analog broadcast signal. The broadcast receiving apparatus according to claim 3, further comprising: a selection unit configured to select a mode in which the channel search is performed among the three modes.