Channel scanning method and broadcast signal receiving apparatus

Abstract

To shorten the time required for channel scanning.SOLUTION: A channel scanning method in a broadcast signal receiving device including a tuner capable of receiving a broadcast signal, the broadcast signal receiving device including a storage unit configured to store a management table indicating a plurality of frequency bands to be selected in channel scanning, the channel scanning method comprising: The channel scanning method includes a step of performing a tuning process of tuning to the frequency band using the tuner, and a step of registering, in the management table, tuning information indicating the presence or absence of the broadcast signal corresponding to the tuned frequency band, and in the step of performing the tuning process, tuning to the frequency band for which the tuning information is not registered in the management table is performed.SELECTED DRAWING: Figure 14

Description

[Technical Field]

[0001] The present disclosure relates to a channel scanning method and a broadcast signal receiving device. [Background technology]

[0002] Conventionally, techniques have been proposed for shortening the time required for channel scanning in broadcast signal receiving devices. For example, Patent Document 1 (JP 2006-254288 A) discloses the following television broadcast receiver. That is, the television broadcast receiver is a receiver that can receive both CATV broadcast signals and terrestrial digital retransmission signals sent to the CATV transmission line without changing the transmission line modulation method of terrestrial digital broadcasts, and is equipped with search means that can shorten the scan time required to search for both receivable broadcast signals when setting a receiving channel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-254288 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-333441 [Patent Document 3] Japanese Patent Application Laid-Open No. 2010-279001 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a need for a technique that can further reduce the time required for channel scanning beyond the techniques described in Patent Documents 1 to 3.

[0005] The present disclosure has been made to solve the above-mentioned problems, and its purpose is to provide a channel scanning method and a broadcast signal receiving device that can further shorten the time required for channel scanning. [Means for solving the problem]

[0006] The channel scanning method disclosed herein is a channel scanning method in a broadcast signal receiving device equipped with a tuner capable of receiving broadcast signals, wherein the broadcast signal receiving device has a memory unit that stores a management table indicating multiple frequency bands to be selected in a channel scan, and the channel scanning method includes a step of performing a tuning process to select the frequency band using the tuner, and a step of registering tuning information in the management table that indicates the presence or absence of a broadcast signal corresponding to the selected frequency band, and in the step of performing the tuning process, tuning is performed to a frequency band for which tuning information is not registered in the management table.

[0007] One aspect of the present disclosure may be realized not only as a broadcast signal receiving device having such a characteristic processing unit, but also as a program for causing a computer to execute the steps of such characteristic processing. Furthermore, one aspect of the present disclosure may be realized as a semiconductor integrated circuit that realizes part or all of the broadcast signal receiving device, or as a system including the broadcast signal receiving device. [Effects of the Invention]

[0008] According to the present disclosure, the time required for channel scanning can be further reduced. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating a configuration of a broadcasting system according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a diagram illustrating an example of a correspondence relationship between a broadcast network in a broadcast system according to the first embodiment of the present disclosure, a transmission method of a broadcast signal in the broadcast network, and a modulation method of the broadcast signal. [Figure 3] FIG. 3 is a diagram showing the correspondence between classifications of frequency ranges used for content distribution in a broadcasting system according to the first embodiment of the present disclosure and the number of physical channels in the frequency ranges. [Figure 4] FIG. 4 is a diagram illustrating an example of a channel list stored in the broadcast signal receiving device according to the first embodiment of the present disclosure. [Figure 5] FIG. 5 is a diagram illustrating a configuration of a broadcast signal receiving device according to the first embodiment of the present disclosure. [Figure 6] FIG. 6 is a diagram illustrating an example of a management table stored in the storage unit in the broadcast signal receiving device according to the first embodiment of the present disclosure. [Figure 7] FIG. 7 is a diagram illustrating an example of a management table stored in the storage unit in the broadcast signal receiving device according to the first embodiment of the present disclosure. [Figure 8] FIG. 8 is a diagram illustrating an example of a management table stored in the storage unit in the broadcast signal receiving device according to the first embodiment of the present disclosure. [Figure 9] FIG. 9 is a diagram illustrating an example of a management table stored in the storage unit in the broadcast signal receiving device according to the first embodiment of the present disclosure. [Figure 10] FIG. 10 is a diagram illustrating an example of a management table stored in the storage unit in the broadcast signal receiving device according to the first embodiment of the present disclosure. [Figure 11] FIG. 11 is a diagram illustrating an example of a management table stored in the storage unit in the broadcast signal receiving device according to the first embodiment of the present disclosure. [Figure 12] FIG. 12 is a diagram illustrating an example of a display screen created by a control unit in the broadcast signal receiving device according to the first embodiment of the present disclosure. [Figure 13] FIG. 13 is a flowchart illustrating an example of an operation procedure when the broadcast signal receiving device according to the first embodiment of the present disclosure performs a channel scan. [Figure 14] FIG. 14 is a flowchart defining an example of an operation procedure when the broadcast signal receiving device according to the first embodiment of the present disclosure registers channel selection information in the management table. [Figure 15] FIG. 15 is a diagram illustrating a configuration of a broadcast signal receiving device according to the second embodiment of the present disclosure. [Figure 16]FIG. 16 is a diagram illustrating an example of a management table stored in a storage unit in a broadcast signal receiving device according to the second embodiment of the present disclosure. [Figure 17] FIG. 17 is a diagram illustrating an example of a management table stored in a storage unit in a broadcast signal receiving device according to the second embodiment of the present disclosure. [Figure 18] FIG. 18 is a diagram illustrating an example of a management table stored in a storage unit in a broadcast signal receiving device according to the second embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] First, the contents of the embodiments of the present disclosure will be listed and described. (1) A channel scanning method according to an embodiment of the present disclosure is a channel scanning method in a broadcast signal receiving device having a tuner capable of receiving broadcast signals, the broadcast signal receiving device having a memory unit that stores a management table indicating a plurality of frequency bands to be selected in a channel scan, the channel scanning method including the steps of: performing a tuning process to select the frequency band using the tuner; and registering tuning information in the management table indicating the presence or absence of a broadcast signal corresponding to the selected frequency band; and in the step of performing the tuning process, tuning is performed to the frequency band for which tuning information is not registered in the management table.

[0011] In this way, by tuning to a frequency band for which tuning information is not registered in the management table and then registering the tuning information corresponding to the selected frequency band in the management table, frequency bands for which tuning information is not available can be efficiently tuned to, and tuning information for each frequency band can be obtained more quickly, thereby further shortening the time required for channel scanning.

[0012] (2) In the above (1), the memory unit may store a first management table as the management table in which first tuning information indicating whether or not the broadcast signal conforms to a transmodulation method is registered, and in the step of registering the tuning information in the management table, the first tuning information corresponding to a frequency band other than the first frequency band among the plurality of frequency bands may be generated based on an NIT included in the broadcast signal of the first frequency band among the plurality of frequency bands, and the generated first tuning information may be registered in the first management table.

[0013] By using this method, it is possible to register the first tuning information corresponding to some frequency bands in the management table while omitting reception of signals in those frequency bands and QAM (Quadrature Amplitude Modulation) demodulation, for example, based on the NIT contained in a broadcast signal transmitted according to a transmodulation method, thereby reducing the time required to register all the first tuning information in the management table.

[0014] (3) In (2) above, the storage unit may further store a second management table as the management table in which second tuning information indicating the presence or absence of the broadcast signal of terrestrial digital broadcasting according to a pass-through method can be registered, and in the step of registering the tuning information in the management table, the second tuning information corresponding to a frequency band other than the first frequency band among the plurality of frequency bands may be generated based on the NIT, and the generated second tuning information may be registered in the second management table.

[0015] By using this method, it is possible to register second tuning information corresponding to some frequency bands in the management table while omitting reception of signals in those frequency bands and OFDM (Orthogonal Frequency Division Multiplexing) demodulation, for example, based on the NIT contained in a broadcast signal transmitted according to a transmodulation method, thereby reducing the time required to register all second tuning information in the management table.

[0016] (4) In (3) above, the tuner may be capable of receiving the broadcast signal transmitted according to a transmodulation method and the broadcast signal of terrestrial digital broadcasting transmitted according to a pass-through method, and in the step of performing the channel selection process, the broadcast signal transmitted according to the transmodulation method may be received in priority over the broadcast signal of terrestrial digital broadcasting transmitted according to the pass-through method.

[0017] This method allows second channel selection information to be registered in the management table in addition to the first channel selection information based on the NIT contained in the broadcast signal transmitted according to the transmodulation method, thereby reducing the number of channel selections required to register all channel selection information in the management table compared to a method in which registration of second channel selection information is given priority over registration of first channel selection information.

[0018] (5) In any of (1) to (4) above, the broadcast signal receiving device may be provided with a plurality of tuners capable of receiving the broadcast signal transmitted according to a transmodulation method, and in the step of performing the tuning process, tuning may be started from a plurality of frequency bands corresponding to the plurality of tuners, respectively, and tuning to the frequency bands may be performed in parallel using the plurality of tuners.

[0019] This method allows efficient channel selection using a plurality of tuners, and reduces the number of channel selections required to register all channel selection information in the management table.

[0020] (6) In the step of performing the tuning process in the above (5), if the tuning information for the second frequency band is obtained by tuning a third frequency band using a second tuner of the plurality of tuners while tuning a second frequency band using a first tuner of the plurality of tuners, tuning to the second frequency band using the first tuner may be terminated.

[0021] In this manner, multiple tuners can be used to efficiently select a station, reducing the total time required for tuning.

[0022] (7) In any of (1) to (6) above, the channel scanning method may further include a step of creating a channel list indicating the correspondence between the channels of the broadcast signal and the frequency bands assigned to the channels based on the management table in which the channel selection information is registered, and a step of performing a preliminary channel selection process using the tuner to select the plurality of frequency bands in a brute force manner after creating the channel list.

[0023] By using this method, if there is an error in the contents of the channel list created based on the results of the channel selection process, the channel list can be updated to an accurate channel list based on the results of the round-robin selection process in the preliminary channel selection process.

[0024] (8) A broadcast signal receiving device according to an embodiment of the present disclosure includes a tuner capable of receiving broadcast signals, a memory unit that stores a management table indicating multiple frequency bands to be selected in a channel scan, a tuning unit that performs tuning processing to select the frequency band using the tuner, and a registration unit that registers tuning information indicating the presence or absence of a broadcast signal corresponding to the frequency band selected by the tuning unit in the management table, and the tuning unit tunes to the frequency band for which tuning information is not registered in the management table.

[0025] In this way, by tuning to a frequency band for which tuning information is not registered in the management table and registering the tuning information corresponding to the selected frequency band in the management table, frequency bands for which tuning information is not available can be efficiently tuned to, and tuning information for each frequency band can be obtained more quickly, thereby further shortening the time required for channel scanning.

[0026] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, identical or corresponding parts are designated by the same reference numerals, and their description will not be repeated. Furthermore, at least some of the embodiments described below may be combined in any manner.

[0027] First Embodiment [Configuration and basic operation] Fig. 1 is a diagram showing the configuration of a broadcasting system according to a first embodiment of the present disclosure. Referring to Fig. 1, a broadcasting system 301 includes a plurality of broadcasting signal receiving devices 101, a plurality of display devices 111, and a broadcasting signal transmitting device 201. The broadcasting signal receiving devices 101 and the display devices 111 are installed in a user's home. The broadcasting signal receiving device 101 is, for example, a set-top box (STB). The broadcasting signal receiving device 101 is connected to the display device 111 via, for example, an HDMI (registered trademark) cable. The display device 111 is, for example, a television device.

[0028] Broadcast signal transmitting device 201 is installed in a station building of a cable television operator that distributes content such as programs. The content includes, for example, audio information, video information, subtitle information, PSI (Program Specific Information), and SI (Service Information). The content includes, as PSI information, a PAT (Program Association Table), a PMT (Program Map Table), a CAT (Conditional Access Table), and an NIT (Network Information Table).

[0029] Broadcast signal transmitting device 201 is capable of receiving a broadcast signal including content via an antenna (not shown) and retransmitting the received broadcast signal. Also, for example, broadcast signal transmitting device 201 is capable of transmitting a broadcast signal including independent broadcast content.

[0030] FIG. 2 is a diagram illustrating an example of a correspondence relationship between a broadcast network in a broadcast system according to the first embodiment of the present disclosure, a transmission method of a broadcast signal in the broadcast network, and a modulation method of the broadcast signal.

[0031] 2, broadcast signal transmitting device 201 is capable of transmitting terrestrial digital broadcast signals in accordance with the pass-through method. The broadcast signals transmitted by broadcast signal transmitting device 201 in accordance with the pass-through method are OFDM modulated.

[0032] In addition, the broadcast signal transmitting device 201 can transmit BS digital broadcast signals, 110 degrees east longitude CS digital broadcast signals, advanced BS digital broadcast signals, ReMux digital broadcast signals, JC-HITS broadcast signals, advanced ReMux digital broadcast signals, advanced JC-HITS broadcast signals, and advanced cable independent broadcast signals according to the transmodulation method. The broadcast signals transmitted by the broadcast signal transmitting device 201 according to the transmodulation method are QAM modulated.

[0033] Broadcast signal receiving device 101 receives broadcast signals via a cable television network. Broadcast signal receiving device 101 generates TS packets by demodulating the received broadcast signals, and acquires content from the generated TS packets. Broadcast signal receiving device 101 plays the acquired content on display device 111 connected to broadcast signal receiving device 101. Display device 111 displays the content played by broadcast signal receiving device 101 on its screen.

[0034] [assignment] FIG. 3 is a diagram showing the correspondence between classifications of frequency ranges used for content distribution in a broadcasting system according to the first embodiment of the present disclosure and the number of physical channels in the frequency ranges.

[0035] 3, in broadcasting system 301, three physical channels are set in the VHF-L (Very High Frequency-Low) band, ten physical channels are set in the MID band, nine physical channels are set in the VHF-H (Very High Frequency-High) band, 41 physical channels are set in the SHB band, and 50 physical channels are set in the UHF (Ultra High Frequency) band. Here, the physical channels refer to frequency band Fb that can be assigned to channels of broadcast signals. The bandwidth of the physical channels is, for example, 6 MHz.

[0036] That is, in the broadcasting system 301, 113 physical channels are set in the frequency range Rf, which ranges from the VHF-L band to the UHF band. For example, when analog broadcasting is also taken into consideration, the frequency range Rf includes 117 frequency bands Fb.

[0037] Each of the channels used for transmitting broadcast signals by the broadcast signal transmitting device 201 is assigned a frequency band Fb within the frequency range Rf.

[0038] For example, during initial setup at a user's home, the broadcast signal receiving device 101 performs a channel scan to select all physical channels in the frequency range Rf, that is, the frequency band Fb.

[0039] 4 is a diagram showing an example of a channel list stored in the broadcast signal receiving device according to the first embodiment of the present disclosure. Referring to FIG. 4, the broadcast signal receiving device 101 creates a channel list Lt indicating the correspondence between broadcast networks, channel numbers of channels of broadcast signals in the broadcast networks, and frequency bands Fb assigned to the channels, based on the results of a channel scan. The broadcast signal receiving device 101 may also create a channel list Lt for each broadcast network.

[0040] When the broadcast signal receiving device 101 receives a user operation to select a channel number, it receives a broadcast signal in the frequency band Fb corresponding to the selected channel number based on the channel list Lt and acquires the content corresponding to that channel number, thereby enabling the broadcast signal receiving device 101 to play and record the content corresponding to the channel number selected by the user.

[0041] In a channel scan, for example, if one tuner supporting QAM is used to sequentially select all frequency bands Fb, and one tuner supporting OFDM is used to sequentially select all frequency bands Fb, it takes a long time to select all frequency bands. In order to shorten the time required for initial setup of broadcast signal receiving device 101, a technique capable of further shortening the time required for channel scan is desired.

[0042] Therefore, the broadcast signal receiving device 101 according to the embodiment of the present disclosure solves the above problem by adopting the following configuration.

[0043] (Broadcast signal receiving device) FIG. 5 is a diagram illustrating a configuration of a broadcast signal receiving device according to the first embodiment of the present disclosure. Referring to FIG. 5, the broadcast signal receiving device 101 includes tuners 10A and 10B, TS processing units 20A and 20B, a content processing unit 30, a control unit 40, and a storage unit 50. The TS processing units 20A and 20B are provided corresponding to the tuners 10A and 10B, respectively. Hereinafter, each of the tuners 10A and 10B will also be referred to as a tuner 10, and each of the TS processing units 20A and 20B will also be referred to as a TS processing unit 20. The tuner 10 includes a receiving unit 11 and a demodulating unit 12. The control unit 40 is an example of a scanning unit and an example of a creating unit. The tuner 10, the TS processing unit 20, the content processing unit 30, and the control unit 40 may be partially or entirely implemented by a processing circuit including one or more processors. The storage unit 50 may be, for example, a non-volatile memory included in the processing circuit. The broadcast signal receiving device 101 may be configured to include one tuner 10 or three or more tuners 10.

[0044] The tuner 10 is capable of receiving broadcast signals. For example, the tuner 10 is capable of receiving broadcast signals transmitted in accordance with the transmodulation method and terrestrial digital broadcast signals transmitted in accordance with the pass-through method. More specifically, the tuner 10 is capable of receiving and demodulating QAM-modulated broadcast signals, and is capable of receiving and demodulating OFDM-modulated broadcast signals.

[0045] The storage unit 50 stores the channel list Lt. The channel list Lt is created by the control unit 40 and stored in the storage unit 50. The method of creating the channel list Lt by the control unit 40 will be described in detail later.

[0046] The control unit 40 acquires a selection operation for selecting a channel number as an operation by the user of the broadcast signal receiving device 101. More specifically, the control unit 40 receives a signal indicating the selection operation from a remote control (not shown).

[0047] When the control unit 40 receives the selection operation, it acquires the frequency band Fb and the broadcast network corresponding to the channel number selected by the user from the channel list Lt in the storage unit 50. The control unit 40 generates a tuning instruction indicating the acquired frequency band Fb and the demodulation method corresponding to the acquired broadcast network, and outputs the generated tuning instruction to the tuner 10.

[0048] When the tuner 10 receives a tuning instruction from the control unit 40, it receives and demodulates a broadcast signal in accordance with the tuning instruction.

[0049] More specifically, the receiving unit 11 receives a broadcast signal of the frequency band Fb indicated by the tuning instruction, and outputs the received broadcast signal to the demodulating unit 12.

[0050] The demodulation unit 12 is capable of performing QAM demodulation and OFDM demodulation. The demodulation unit 12 generates TS packets by demodulating the broadcast signal received from the receiving unit 11 according to the demodulation method indicated by the channel selection instruction. The demodulation unit 12 outputs the generated TS packets to the corresponding TS processing unit 20.

[0051] The TS processing unit 20 receives the TS packets from the demodulation unit 12, acquires the content from the received TS packets, and outputs the acquired content to the content processing unit 30.

[0052] The content processing unit 30 receives content from the TS processing unit 20, performs processing to play the received content, and transmits the resulting video signal and audio signal to the display device 111. More specifically, the content processing unit 30 generates a video signal by decoding the video information, and generates an audio signal by decoding the audio information. The content processing unit 30 transmits the generated video signal and audio signal to the display device 111. Note that the content processing unit 30 may also generate an electronic program guide and transmit to the display device 111 a video signal to which information from the generated electronic program guide has been added.

[0053] (Channel Scan) The control unit 40 performs a channel scan in accordance with, for example, a user operation for initializing the broadcast signal receiving device 101. Note that, when the user moves, the control unit 40 may perform a channel scan in accordance with a user operation for updating the channel list Lt. The control unit 40 may also perform a channel scan in accordance with an instruction from the broadcast signal transmitting device 201.

[0054] 6 is a diagram illustrating an example of a management table stored in a storage unit in the broadcast signal receiving device according to the first embodiment of the present disclosure, showing a management table Tb in an initial state before a channel scan is started.

[0055] Referring to FIG. 6, the storage unit 50 stores a management table Tb indicating a plurality of frequency bands Fb to be selected in a channel scan. More specifically, the management table Tb indicates the correspondence between the classification of frequency ranges used for content distribution in the broadcasting system 301 and the center frequencies of the frequency bands Fb in the frequency ranges. That is, the management table Tb indicates a list of frequency bands Fb, i.e., physical channels, in the frequency range Rf. The management table Tb can register tuning information S1 indicating the presence or absence of a broadcast signal conforming to the transmodulation method and tuning information S2 indicating the presence or absence of a terrestrial digital broadcast signal conforming to the pass-through method. The management table Tb is an example of a first management table and an example of a second management table. The tuning information S1 is an example of the first tuning information, and the tuning information S2 is an example of the second tuning information.

[0056] The channel selection information S1 is information indicating whether or not a QAM-modulated broadcast signal is present, the broadcast network corresponding to the broadcast signal, the channel number of the broadcast signal, etc. The channel selection information S2 is information indicating whether or not an OFDM-modulated broadcast signal is present, the broadcast network corresponding to the broadcast signal, the channel number of the broadcast signal, etc. Hereinafter, each of the channel selection information S1 and S2 will also be referred to as channel selection information S. For example, before the start of channel scanning, the channel selection information S1 and S2 are not registered in the management table Tb.

[0057] The control unit 40 performs a tuning process to tune to the frequency band Fb using the tuner 10. Then, the control unit 40 registers the tuning information S corresponding to the selected frequency band Fb in the management table Tb. The control unit 40 tunes to the frequency band Fb for which the tuning information S is not registered in the management table Tb.

[0058] More specifically, the control unit 40 determines a frequency band Fb for which tuning information S is not registered in the management table Tb as the tuning target, and determines either OFDM demodulation or QAM demodulation as the demodulation method. The control unit 40 outputs a scan instruction indicating the determined frequency band Fb and demodulation method to the tuner 10 and the TS processing unit 20. The control unit 40 also outputs a transfer instruction indicating the PID (Packet IDentifier) ​​of the NIT to the TS processing unit 20.

[0059] The receiver 11 in the tuner 10 receives a signal in the frequency band Fb indicated by a scan instruction received from the controller 40, and outputs the received signal to the demodulator 12. The demodulator 12 demodulates the signal received from the receiver 11 according to the demodulation method indicated by the scan instruction. For example, if the demodulator 12 can generate TS packets by demodulating the signal received from the receiver 11, it outputs the generated TS packets to the corresponding TS processor 20.

[0060] When the TS processing unit 20 receives a TS packet from the demodulation unit 12, it acquires the NIT from the received TS packet based on the PID indicated in the transfer instruction received from the control unit 40. The TS processing unit 20 outputs the acquired NIT to the control unit 40.

[0061] On the other hand, if the TS processing unit 20 does not receive a TS packet from the demodulation unit 12 within a predetermined time after receiving a scan instruction from the control unit 40, the TS processing unit 20 times out and outputs a no-signal notification indicating that no broadcast signal is being transmitted in the frequency band Fb to be selected to the control unit 40. The time from when the TS processing unit 20 receives a scan instruction to when the timeout occurs is set based on, for example, the transmission cycle of the NIT.

[0062] When the control unit 40 receives the NIT from the TS processing unit 20, it acquires from the received NIT a descriptor Ds including a network ID that is an identifier of the broadcast network, a service ID that is an identifier corresponding to the channel number, and frequency information A that indicates the frequency band Fb allocated to the channel. Based on the acquired descriptor Ds, the control unit 40 generates channel selection information S that indicates "broadcast signal available" and registers the generated channel selection information S in the management table Tb.

[0063] On the other hand, when the control unit 40 receives a no-signal notification from the TS processing unit 20, it generates channel selection information S indicating "no broadcast signal" and registers the generated channel selection information S in the management table Tb.

[0064] When the control unit 40 registers the channel selection information S in the management table Tb, it determines a frequency band Fb for which channel selection information S is not registered in the management table Tb as a new channel to be selected, and outputs a scan instruction to the tuner 10 and the TS processing unit 20. The control unit 40 repeats the process of determining a new channel to be selected, outputting a scan instruction, and registering the channel selection information S in the management table Tb until it has registered channel selection information S corresponding to all frequency bands Fb in the management table Tb.

[0065] The control unit 40 creates a channel list Lt indicating the correspondence between the channels of broadcast signals and the frequency bands Fb assigned to those channels, based on the management table Tb in which the channel selection information S is registered. More specifically, after completing the registration of the channel selection information S1, S2 corresponding to all frequency bands Fb in the management table Tb, the control unit 40 creates the channel list Lt based on the management table Tb.

[0066] (Example of channel selection processing during channel scanning) For example, control unit 40 starts tuning from a plurality of frequency bands Fb corresponding to the plurality of tuners 10, respectively, and performs tuning to the frequency bands Fb in parallel using the plurality of tuners 10. As an example, control unit 40 determines the frequency bands Fb to be tuned to using tuner 10A in ascending order, for example, starting from the lowest frequency band Fb, and determines the frequency bands Fb to be tuned to using tuner 10B in ascending order, for example, starting from the frequency band Fb with a center frequency of 473 MHz.

[0067] In addition, for example, in the channel selection process, the control unit 40 receives broadcast signals transmitted in accordance with the transmodulation method with priority over terrestrial digital broadcast signals transmitted in accordance with the pass-through method. The control unit 40 also performs the process of registering channel selection information S1 in the management table Tb with priority over the process of registering channel selection information S2 in the management table Tb.

[0068] More specifically, the control unit 40 determines the frequency band Fb to be selected using the tuner 10A to be the frequency band Fb with a center frequency of 93 MHz, and determines the demodulation method to be QAM demodulation. The control unit 40 outputs a scan command indicating the determined frequency band Fb and demodulation method to the tuner 10A and the TS processing unit 20A.

[0069] The control unit 40 also determines the frequency band Fb to be selected using the tuner 10B to be the frequency band Fb with a center frequency of 473 MHz, and determines the demodulation method to be QAM demodulation. The control unit 40 outputs a scan command indicating the determined frequency band Fb and demodulation method to the tuner 10B and the TS processing unit 20B.

[0070] 7 to 11 are diagrams illustrating an example of a management table stored in a storage unit in the broadcast signal receiving device according to the first embodiment of the present disclosure. Figures 7 to 11 show the transition of the management table Tb updated by the control unit 40 during a channel scan.

[0071] 7, for example, the control unit 40 registers in the management table Tb the channel selection information S1 corresponding to the frequency band Fb having a center frequency of 93 MHz, indicating that "tuning is currently being performed using the tuner 10A," as the channel selection information S1 corresponding to the frequency band Fb having a center frequency of 93 MHz, until it receives an NIT or a no-signal notification from the TS processing unit 20A. Also, for example, the control unit 40 registers in the management table Tb the channel selection information S1 corresponding to the frequency band Fb having a center frequency of 473 MHz, indicating that "tuning is currently being performed using the tuner 10B," as the channel selection information S1 corresponding to the frequency band Fb having a center frequency of 473 MHz, until it receives an NIT or a no-signal notification from the TS processing unit 20B.

[0072] Referring to Figure 8, next, the control unit 40 receives a no-signal notification, for example from the TS processing unit 20B, and updates the tuning information S1 corresponding to the frequency band Fb having a center frequency of 473 MHz in the management table Tb to tuning information S1 indicating "no broadcast signal."

[0073] Furthermore, the control unit 40 receives, for example, an NIT from the TS processing unit 20A, and acquires a descriptor Ds including a network ID for BS digital broadcasting from the received NIT. Based on the acquired descriptor Ds, the control unit 40 generates tuning information S1 indicating "BS digital broadcast signal available," and updates the tuning information S1 corresponding to frequency band Fb with a center frequency of 93 MHz in management table Tb to the generated tuning information S1. Frequency band Fb with a center frequency of 93 MHz is an example of a first frequency band.

[0074] Furthermore, because frequency band Fb assigned to a BS digital broadcasting channel cannot be assigned to a terrestrial digital broadcasting channel in the same way, control unit 40 registers in management table Tb tuning information S2 indicating "no broadcast signal" as tuning information S2 corresponding to frequency band Fb with a center frequency of 93 MHz. This allows tuning information S2 corresponding to frequency band Fb with a center frequency of 93 MHz to be registered in management table Tb, while omitting reception and OFDM demodulation of the signal for frequency band Fb with a center frequency of 93 MHz.

[0075] Referring to Figure 9, for example, the control unit 40 generates tuning information S1 corresponding to a frequency band Fb other than the frequency band Fb based on the NIT contained in a broadcast signal of the frequency band Fb having a center frequency of 93 MHz, and registers the generated tuning information S1 in the management table Tb.

[0076] More specifically, the descriptor Ds, which is obtained from the broadcast signal and includes the network ID of the broadcast network corresponding to the transmodulation method, includes, as frequency information A, frequency information A1 indicating the frequency band Fb assigned to the channel of the broadcast signal, as well as frequency information A2 indicating the frequency band Fb assigned to another channel of the broadcast network.

[0077] The control unit 40 detects a frequency band Fb assigned to another channel of the BS digital broadcasting based on the frequency information A2 included in the descriptor Ds. The control unit 40 then registers, in the management table Tb, the channel tuning information S1 indicating "BS digital broadcast signal present" as the channel tuning information S1 corresponding to the detected frequency band Fb. This allows the channel tuning information S1 corresponding to the detected frequency band Fb to be registered in the management table Tb without receiving and QAM demodulating the signal of the detected frequency band Fb. Generally, channels of the same broadcast network tend to be assigned frequency bands Fb that are close to each other. Therefore, for example, in order to efficiently generate and register the channel tuning information S1, the control unit 40 determines two dispersed frequency bands Fb whose center frequency difference is equal to or greater than a predetermined value as the frequency bands Fb to be tuned using the tuners 10A and 10B. Furthermore, for example, the control unit 40 determines, as the frequency bands Fb to be tuned using the tuners 10A and 10B, two frequency bands Fb that belong to different frequency range classifications.

[0078] Furthermore, for example, the control unit 40 generates tuning information S2 corresponding to a frequency band Fb other than the frequency band Fb based on the NIT contained in the broadcast signal of the frequency band Fb having a center frequency of 93 MHz, and registers the generated tuning information S2 in the management table Tb.

[0079] More specifically, because frequency band Fb assigned to a BS digital broadcasting channel cannot be assigned to a terrestrial digital broadcasting channel in the same way, control unit 40 registers in management table Tb tuning information S2 indicating "no broadcast signal" as tuning information S2 corresponding to frequency band Fb with a center frequency of 99 MHz, etc. This allows tuning information S2 corresponding to frequency band Fb with a center frequency of 99 MHz, etc., to be registered in management table Tb while omitting reception and OFDM demodulation of signals from frequency band Fb with a center frequency of 99 MHz, etc.

[0080] Next, the control unit 40 determines the frequency band Fb to be newly selected using the tuner 10A in ascending order as described above. Specifically, the control unit 40 determines the frequency band Fb to be newly selected using the tuner 10A to be the frequency band Fb with a center frequency of 173 MHz, which is the lowest frequency band Fb among the frequency bands Fb for which the channel selection information S1 has not been registered. The control unit 40 also determines the demodulation method to be QAM demodulation. The control unit 40 outputs a scan instruction indicating the determined frequency band Fb and demodulation method to the tuner 10A and the TS processing unit 20A. The control unit 40 then registers the channel selection information S1 indicating that "tuning is currently being performed using the tuner 10A" in the management table Tb as the channel selection information S1 corresponding to the frequency band Fb with a center frequency of 173 MHz until it receives an NIT or no-signal notification from the TS processing unit 20A.

[0081] The control unit 40 also determines the frequency band Fb to be newly selected using the tuner 10B in ascending order as described above. Specifically, the control unit 40 determines the frequency band Fb to be newly selected using the tuner 10B to be the frequency band Fb with a center frequency of 479 MHz, which is higher than the frequency band Fb with a center frequency of 473 MHz and is the lowest frequency band Fb among the frequency bands Fb for which the channel selection information S1 has not been registered. The control unit 40 also determines the demodulation method to be QAM demodulation. The control unit 40 outputs a scan instruction indicating the determined frequency band Fb and demodulation method to the tuner 10B and the TS processing unit 20B. The control unit 40 then registers the channel selection information S1 indicating that "tuning is being performed using the tuner 10B" in the management table Tb as the channel selection information S1 corresponding to the frequency band Fb with a center frequency of 479 MHz until it receives an NIT or no-signal notification from the TS processing unit 20B.

[0082] For example, in some physical channels, two frequency bands Fb with a center frequency interval of 2 MHz may be assigned to one physical channel as an exception. Specifically, physical channel C24 is assigned a frequency band Fb with a center frequency of 231 MHz and a frequency band Fb with a center frequency of 233 MHz. Physical channel C25 is assigned a frequency band Fb with a center frequency of 237 MHz and a frequency band Fb with a center frequency of 239 MHz. Physical channel C26 is assigned a frequency band Fb with a center frequency of 243 MHz and a frequency band Fb with a center frequency of 245 MHz. Physical channel C27 is assigned a frequency band Fb with a center frequency of 249 MHz and a frequency band Fb with a center frequency of 251 MHz.

[0083] When the control unit 40 registers the tuning information S1 indicating "broadcast signal present" as the tuning information S1 corresponding to a first frequency band Fb of the two frequency bands Fb assigned to the part of the physical channels, the control unit 40 registers the tuning information S1 indicating "broadcast signal absent" as the tuning information S1 corresponding to the second frequency band Fb without tuning to the second frequency band Fb because the second frequency band Fb cannot be assigned to a channel. This makes it possible to register the tuning information S1 corresponding to the part of the frequency bands Fb in the management table Tb while omitting reception and demodulation of signals from the part of the frequency bands Fb.

[0084] 10, the control unit 40 repeats determining the frequency band Fb to be tuned and registering the channel tuning information S1 until it has registered the channel tuning information S1 corresponding to all of the frequency bands Fb in the management table Tb. That is, the control unit 40 does not fixedly assign the frequency band Fb to be tuned to each tuner 10, but rather uses each tuner 10 to sequentially tune to frequency bands Fb for which channel tuning information S1 is not registered until it has registered the channel tuning information S1 corresponding to all of the frequency bands Fb in the management table Tb. When the control unit 40 has registered the channel tuning information S1 corresponding to all of the frequency bands Fb in the management table Tb, it performs a process of registering the unregistered channel tuning information S2 in the management table Tb.

[0085] More specifically, the control unit 40 determines the frequency band Fb to be newly selected using the tuner 10A to be, for example, the 473 MHz frequency band Fb, and determines the demodulation method to be OFDM demodulation. The control unit 40 outputs a scan command indicating the determined frequency band Fb and demodulation method to the tuner 10A and the TS processing unit 20A. The control unit 40 then registers the channel selection information S2 indicating that "a channel is being selected using the tuner 10A" in the management table Tb as the channel selection information S2 corresponding to the frequency band Fb having a center frequency of 473 MHz, until it receives an NIT or no-signal notification from the TS processing unit 20A.

[0086] The control unit 40 also determines the frequency band Fb to be newly selected using the tuner 10B to be, for example, the 479 MHz frequency band Fb, and determines the demodulation method to be OFDM demodulation. The control unit 40 outputs a scan instruction indicating the determined frequency band Fb and demodulation method to the tuner 10B and the TS processing unit 20B. The control unit 40 then registers in the management table Tb the channel selection information S2 indicating that "channel selection is currently being performed using the tuner 10B" as the channel selection information S2 corresponding to the frequency band Fb having a center frequency of 479 MHz, until it receives an NIT or no-signal notification from the TS processing unit 20B.

[0087] Next, the control unit 40 receives, for example, an NIT from the TS processing unit 20A and acquires a descriptor Ds including a network ID for terrestrial digital broadcasting from the received NIT. Based on the acquired descriptor Ds, the control unit 40 generates tuning information S2 indicating "terrestrial digital broadcasting signal present," and updates the tuning information S2 in the management table Tb corresponding to the frequency band Fb with a center frequency of 473 MHz to the generated tuning information S2. Note that, when the control unit 40 receives a no-signal notification from the TS processing unit 20A, it updates the tuning information S2 in the management table Tb corresponding to the frequency band Fb with a center frequency of 473 MHz to the tuning information S2 indicating "no broadcast signal."

[0088] Similarly, the control unit 40 receives the NIT from the TS processing unit 20B, generates tuning information S2, and updates the tuning information S2 corresponding to the frequency band Fb with a center frequency of 479 MHz in the management table Tb to the generated tuning information S2.

[0089] The control unit 40 repeats the determination of the frequency band Fb to be tuned and the registration of the channel tuning information S2 until it has registered the channel tuning information S2 corresponding to all of the frequency bands Fb in the management table Tb. That is, the control unit 40 does not fixedly assign the frequency bands Fb to be tuned to each tuner 10, but instead uses each tuner 10 to sequentially tune to frequency bands Fb for which channel tuning information S2 is not registered until it has registered the channel tuning information S2 corresponding to all of the frequency bands Fb in the management table Tb.

[0090] 11, when the control unit 40 has registered the tuning information S1 and S2 corresponding to all frequency bands Fb in the management table Tb, the control unit 40 ends the channel scan. Then, the control unit 40 creates a channel list Lt based on the management table Tb and stores the created channel list Lt in the storage unit 50.

[0091] For example, after creating the channel list Lt, the control unit 40 performs a preliminary tuning process in which the control unit 40 uses the tuner 10 to tune in to a plurality of frequency bands Fb in a round-robin manner. More specifically, in the preliminary tuning process, the control unit 40 initializes the management table Tb and deletes all of the tuning information S1 and S2. Then, the control unit 40 sequentially tunes in to all of the frequency bands Fb in the management table Tb using the tuner 10 without skipping signal reception and demodulation, generates tuning information S1 and S2, and registers it in the management table Tb.

[0092] 12 is a diagram showing an example of a display screen created by a control unit in the broadcast signal receiving device according to the first embodiment of the present disclosure. Referring to FIG. 12, when control unit 40 receives a channel scan instruction from broadcast signal transmitting device 201, for example, control unit 40 creates display screen G1 indicating that a channel scan will be performed, and performs processing to display the created display screen on display device 111.

[0093] Then, the control unit 40 performs a preliminary tuning process, registers the tuning information S1 and S2 in the management table Tb, and creates a channel list Lt. In addition to the tuning process of registering the tuning information S in the management table Tb while omitting the reception and demodulation of signals in some frequency bands Fb as described above, by performing the preliminary tuning process, if there is an error in the content of the channel list Lt created based on the results of the tuning process, the channel list Lt can be updated to an accurate channel list Lt.

[0094] [Operation flow] FIG. 13 is a flowchart illustrating an example of an operation procedure when the broadcast signal receiving device according to the first embodiment of the present disclosure performs a channel scan.

[0095] 13, first, broadcast signal receiving device 101 tunes to frequency band Fb and registers tuning information S in management table Tb. For example, broadcast signal receiving device 101 starts tuning to two frequency bands Fb corresponding to tuners 10A and 10B, respectively, and tunes to frequency band Fb in parallel using tuners 10A and 10B. Also, for example, in tuning to frequency band Fb using tuners 10A and 10B, broadcast signal receiving device 101 receives broadcast signals transmitted in accordance with a transmodulation method with priority over terrestrial digital broadcast broadcast signals transmitted in accordance with a pass-through method (step S11).

[0096] Next, the broadcast signal receiving device 101 repeats the processing of step S11 until it has registered the tuning information S corresponding to all frequency bands Fb in the management table Tb (NO in step S12), and when it has completed registering the tuning information S1, S2 corresponding to all frequency bands Fb in the management table Tb (YES in step S12), it creates a channel list Lt based on the management table Tb (step S13).

[0097] 14 is a flowchart illustrating an example of an operation procedure when the broadcast signal receiving device according to the first embodiment of the present disclosure registers channel selection information in the management table. FIG. 14 illustrates details of step S11 in FIG.

[0098] Referring to Figure 14, first, the broadcast signal receiving device 101 determines a frequency band Fb among the multiple frequency bands Fb in the management table Tb for which tuning information S1 is not registered as the tuning target, and receives and QAM demodulates the signal of that frequency band Fb (step S21).

[0099] Next, if the broadcast signal receiving device 101 is unable to generate a TS packet by QAM demodulating the received signal (NO in step S22), it registers channel selection information S1 indicating "no broadcast signal" in the management table Tb (step S23).

[0100] On the other hand, if broadcast signal receiving device 101 can generate TS packets by QAM demodulating the received signal (YES in step S22), it acquires the NIT from the TS packets (step S24).

[0101] Next, the broadcast signal receiving device 101 generates tuning information S1 indicating "broadcast signal available" based on the descriptor Ds included in the acquired NIT, and registers the generated tuning information S1 in the management table Tb. For example, the broadcast signal receiving device 101 further generates tuning information S1 corresponding to another frequency band Fb other than the frequency band Fb in the same broadcast network based on the NIT included in the broadcast signal of the frequency band Fb to be selected, and further registers the generated tuning information S1 in the management table Tb (step S25).

[0102] Next, based on the NIT, the broadcast signal receiving device 101 generates channel selection information S2 corresponding to the frequency band Fb to be tuned to and channel selection information S2 corresponding to frequency bands Fb other than the frequency band Fb, and registers the generated channel selection information S2 in the management table Tb. More specifically, since multiple frequency bands Fb for which channel selection information S1 indicating "broadcast signal present" has been registered cannot be assigned to terrestrial digital broadcasting channels in duplicate, the broadcast signal receiving device 101 registers channel selection information S2 indicating "broadcast signal absent" in the management table Tb as channel selection information S2 corresponding to the multiple frequency bands Fb (step S26).

[0103] Next, if there are any frequency bands Fb for which tuning information S1 is not registered in the management table Tb (NO in step S27), the broadcast signal receiving device 101 repeats the processing from step S21 to step S26, and if tuning information S1 corresponding to all frequency bands Fb in the management table Tb has been registered (YES in step S27), it determines the frequency bands Fb for which tuning information S2 is not registered as the tuning target, and receives and OFDM demodulates the signals of those frequency bands Fb (step S28).

[0104] Next, if the broadcast signal receiving device 101 is unable to generate a TS packet by OFDM demodulating the received signal (NO in step S29), it registers channel selection information S2 indicating "no broadcast signal" in the management table Tb (step S30).

[0105] On the other hand, if broadcast signal receiving device 101 can generate TS packets by OFDM demodulating the received signal (YES in step S29), it acquires the NIT from the TS packets (step S31).

[0106] Next, the broadcast signal receiving device 101 generates channel selection information S2 indicating "broadcast signal available" based on the descriptor Ds included in the acquired NIT, and registers the generated channel selection information S2 in the management table Tb (step S32).

[0107] Next, if there are any frequency bands Fb in the management table Tb for which tuning information S2 has not been registered (NO in step S33), the broadcast signal receiving device 101 repeats the processing from step S28 to step S32, and when tuning information S2 corresponding to all frequency bands Fb in the management table Tb has been registered (YES in step S33), it terminates the channel scan.

[0108] In the broadcast signal receiving device 101 according to the first embodiment of the present disclosure, the control unit 40 is configured to generate tuning information S1 corresponding to a frequency band Fb other than the frequency band Fb based on the NIT included in the broadcast signal of the frequency band Fb and register the generated tuning information S1 in the management table Tb, but this is not limiting. The control unit 40 may be configured to generate tuning information S1 corresponding to the frequency band Fb based on the NIT included in the broadcast signal of the frequency band Fb and register the generated tuning information S1 in the management table Tb, but not to generate or register tuning information S1 corresponding to the frequency band Fb other than the frequency band Fb.

[0109] Furthermore, in the broadcast signal receiving device 101 according to the first embodiment of the present disclosure, the control unit 40 is configured to generate tuning information S2 corresponding to a frequency band Fb other than the frequency band Fb based on the NIT included in the broadcast signal of the frequency band Fb and register the generated tuning information S2 in the management table Tb, but this is not limited to this. The control unit 40 may be configured to generate tuning information S2 corresponding to the frequency band Fb based on the NIT included in the broadcast signal of the frequency band Fb and register the generated tuning information S2 in the management table Tb, but not to generate and register tuning information S2 corresponding to the frequency band Fb other than the frequency band Fb.

[0110] Furthermore, in the broadcast signal receiving device 101 according to the first embodiment of the present disclosure, the control unit 40 is configured to receive broadcast signals transmitted in accordance with the transmodulation method in preference to terrestrial digital broadcast signals transmitted in accordance with the pass-through method in the channel selection process, but this is not limited to this. In the channel selection process, the control unit 40 may output a scan instruction indicating OFDM demodulation as the demodulation method to the tuner 10 and the TS processing unit 20, and generate and register channel selection information S2 before completing the registration of channel selection information S1 corresponding to all frequency bands Fb in the management table Tb.

[0111] Furthermore, in the broadcast signal receiving device 101 according to the first embodiment of the present disclosure, the control unit 40 is configured to perform the preliminary channel selection process, but this is not limiting. The control unit 40 may be configured not to perform the preliminary channel selection process.

[0112] Next, other embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals and their description will not be repeated.

[0113] <Second embodiment> This embodiment relates to a broadcast signal receiving device 102 that performs QAM modulation of a signal in a frequency band Fb to be selected and OFDM modulation of a signal in a frequency band Fb to be selected in parallel, as compared with the broadcast signal receiving device 101 according to the first embodiment. Except for the details described below, the present embodiment is the same as the broadcast signal receiving device 101 according to the first embodiment.

[0114] FIG. 15 is a diagram illustrating a configuration of a broadcast signal receiving device according to a second embodiment of the present disclosure. Compared to broadcast signal receiving device 101, broadcast signal receiving device 102 includes tuners 60A, 60B, 70A, and 70B instead of tuner 10, and includes a control unit 80 instead of control unit 40. Broadcast signal receiving device 102 also includes TS processing units 20A1 and 20A2, which are TS processing unit 20A, and TS processing units 20B1 and 20B2, which are TS processing unit 20B. TS processing units 20A1, 20A2, 20B1, and 20B2 are provided corresponding to tuners 60A, 60B, 70A, and 70B, respectively. Hereinafter, each of tuners 60A and 60B will also be referred to as tuner 60, and each of tuners 70A and 70B will also be referred to as tuner 70. Compared to tuner 10, tuner 60 includes a demodulation unit 62 instead of demodulation unit 12. Compared to tuner 10, tuner 70 includes a demodulation unit 72 instead of demodulation unit 12. Note that broadcast signal receiving device 102 may be configured to include one or three or more tuners 60, or one or three or more tuners 70.

[0115] The tuner 60 is capable of receiving broadcast signals transmitted in accordance with the transmodulation method. More specifically, the tuner 60 is capable of receiving and demodulating QAM-modulated broadcast signals. The demodulation unit 62 generates TS packets by QAM-demodulating the broadcast signals received from the receiving unit 11, and outputs the generated TS packets to the corresponding TS processing unit 20A.

[0116] The tuner 70 is capable of receiving terrestrial digital broadcast signals transmitted in accordance with the pass-through method. More specifically, the tuner 70 is capable of receiving and demodulating OFDM-modulated broadcast signals. The demodulation unit 72 generates TS packets by OFDM-demodulating the broadcast signals received from the receiving unit 11, and outputs the generated TS packets to the corresponding TS processing unit 20B.

[0117] (Example of channel selection processing during channel scanning) For example, the control unit 80 starts tuning from four frequency bands Fb corresponding to the tuners 60A, 60B, 70A, and 70B, respectively, and simultaneously tunes to the frequency bands Fb using the tuners 60A, 60B, 70A, and 70B. As an example, the control unit 80 determines the frequency bands Fb to be selected using the tuner 60A in ascending order, starting from the frequency band Fb with a center frequency of 93 MHz, and determines the frequency bands Fb to be selected using the tuner 60B in ascending order, starting from the frequency band Fb with a center frequency of 219 MHz. The control unit 80 also determines the frequency bands Fb to be selected using the tuner 70A in ascending order, starting from the frequency band Fb with a center frequency of 111 MHz, and determines the frequency bands Fb to be selected using the tuner 70B in ascending order, starting from the frequency band Fb with a center frequency of 473 MHz.

[0118] The control unit 80 outputs a scan instruction indicating the frequency band Fb to be selected using tuner 60A to tuner 60A and TS processing unit 20A1, and outputs a scan instruction indicating the frequency band Fb to be selected using tuner 60B to tuner 60B and TS processing unit 20A2. The control unit 80 also outputs a scan instruction indicating the frequency band Fb to be selected using tuner 70A to tuner 70A and TS processing unit 20B1, and outputs a scan instruction indicating the frequency band Fb to be selected using tuner 70B to tuner 70B and TS processing unit 20B2.

[0119] 16 to 18 are diagrams illustrating an example of a management table stored in a storage unit in a broadcast signal receiving device according to a second embodiment of the present disclosure. Figures 16 to 18 show the transition of the management table Tb updated by the control unit 80 during a channel scan.

[0120] 16, for example, the control unit 80 registers in the management table Tb the tuning information S1 corresponding to the frequency band Fb having a center frequency of 93 MHz, indicating that "tuning is currently being performed using the tuner 60A," as the tuning information S1 corresponding to the frequency band Fb having a center frequency of 93 MHz, until it receives an NIT or a no-signal notification from the TS processing unit 20A1. Furthermore, for example, the control unit 80 registers in the management table Tb the tuning information S1 corresponding to the frequency band Fb having a center frequency of 219 MHz, indicating that "tuning is currently being performed using the tuner 60B," as the tuning information S1 corresponding to the frequency band Fb having a center frequency of 219 MHz, until it receives an NIT or a no-signal notification from the TS processing unit 20A2. The frequency band Fb having a center frequency of 93 MHz is an example of the second frequency band. The frequency band Fb having a center frequency of 219 MHz is an example of the third frequency band.

[0121] Furthermore, for example, the control unit 80 registers in the management table Tb the channel selection information S2 indicating that "tuning is currently being performed using tuner 70A" as the channel selection information S2 corresponding to frequency band Fb having a center frequency of 111 MHz until receiving an NIT or a no-signal notification from the TS processing unit 20B1. Furthermore, for example, the control unit 80 registers in the management table Tb the channel selection information S2 indicating that "tuning is currently being performed using tuner 70B" as the channel selection information S2 corresponding to frequency band Fb having a center frequency of 473 MHz until receiving an NIT or a no-signal notification from the TS processing unit 20B2. The frequency band Fb having a center frequency of 111 MHz is an example of the third frequency band.

[0122] 17, the control unit 80 then receives the NIT from the TS processing unit 20A1, and acquires a descriptor Ds including a network ID of the BS digital broadcasting from the received NIT. Based on the acquired descriptor Ds, the control unit 80 generates tuning information S1 indicating "BS digital broadcasting signal available," and updates the tuning information S1 in the management table Tb that corresponds to the frequency band Fb with a center frequency of 93 MHz to the generated tuning information S1.

[0123] For example, when tuning to frequency band Fb using tuner 60B, if tuning information S1 for frequency band Fb being tuned using tuner 60B is obtained by tuning to frequency band Fb using tuner 60A, control unit 80 terminates tuning to frequency band Fb using tuner 60B.

[0124] More specifically, the control unit 80 detects a frequency band Fb assigned to another channel of BS digital broadcasting based on frequency information A2 included in descriptor Ds in the NIT received from the TS processing unit 20A1. Then, the control unit 80 registers, in management table Tb, channel selection information S1 indicating "BS digital broadcast signal available" as channel selection information S1 corresponding to the detected frequency band Fb. If the detected frequency bands Fb include the frequency band Fb currently selected using tuner 60B, the control unit 80 outputs a stop instruction to tuner 60B and the TS processing unit 20A2 to stop receiving and demodulating the signal.

[0125] In tuner 60B, receiving unit 11 stops receiving signals in frequency band Fb with a center frequency of 219 MHz in accordance with the stop instruction received from control unit 80. Also, demodulating unit 62 stops QAM demodulation of the signal received from receiving unit 11 in accordance with the stop instruction received from control unit 80.

[0126] For example, when tuning to frequency band Fb using tuner 70A, if tuning information S2 for frequency band Fb being selected using tuner 70A is obtained by tuning to frequency band Fb using tuner 60A, the control unit 80 terminates tuning to frequency band Fb using tuner 70A.

[0127] More specifically, because frequency band Fb assigned to a BS digital broadcasting channel cannot be assigned to a terrestrial digital broadcasting channel in the same way, control unit 80 registers tuning information S2 indicating "no broadcast signal" in management table Tb as tuning information S2 corresponding to frequency band Fb with a center frequency of 111 MHz, etc. Then, control unit 80 outputs a stop instruction to tuner 70A and TS processing unit 20B1 to stop receiving and demodulating the signal.

[0128] In tuner 70A, receiving unit 11 stops receiving signals in frequency band Fb with a center frequency of 111 MHz in accordance with the stop instruction received from control unit 80. Also, demodulating unit 72 stops OFDM demodulation of the signal received from receiving unit 11 in accordance with the stop instruction received from control unit 80.

[0129] Referring to FIG. 18, next, control unit 80 determines, in ascending order as described above, frequency bands Fb to be newly selected using tuners 60A, 60B, and 70A.

[0130] Specifically, the control unit 80 determines the frequency band Fb with a center frequency of 173 MHz as the frequency band Fb to be newly selected using the tuner 60A, and outputs a scan command indicating the determined frequency band Fb to the tuner 60A and the TS processing unit 20A1. Then, the control unit 80 registers in the management table Tb the channel selection information S1 indicating that "a channel is being selected using the tuner 60A."

[0131] The control unit 80 also determines the frequency band Fb with a center frequency of 225 MHz as the new target frequency band Fb for tuning using the tuner 60B, and outputs a scan command indicating the determined frequency band Fb to the tuner 60B and the TS processing unit 20A2. The control unit 80 then registers in the management table Tb tuning information S1 indicating that "tuner 60B is currently being used to tune in."

[0132] The control unit 80 also determines the frequency band Fb with a center frequency of 173 MHz as the new target frequency band Fb for tuning using the tuner 70A, and outputs a scan command indicating the determined frequency band Fb to the tuner 70A and the TS processing unit 20B1. The control unit 80 then registers in the management table Tb tuning information S2 indicating that "tuner 70A is currently being used to tune in."

[0133] The control unit 80 repeats the determination of the frequency band Fb to be selected and the registration of the channel selection information S1, S2 until it has registered the channel selection information S1, S2 corresponding to all frequency bands Fb in the management table Tb. When the control unit 80 has registered the channel selection information S1, S2 corresponding to all frequency bands Fb in the management table Tb, the control unit 80 ends the channel scan. Then, the control unit 80 creates a channel list Lt based on the management table Tb and stores the created channel list Lt in the storage unit 50. For example, after creating the channel list Lt, the control unit 80 performs the above-mentioned preliminary channel selection process.

[0134] In the broadcast signal receiving device 102 according to the second embodiment of the present disclosure, the control unit 80 is configured to terminate tuning of the frequency band Fb using the tuner 60B when tuning of the frequency band Fb using the tuner 60A results in the acquisition of tuning information S1 for the currently selected frequency band Fb using the tuner 60B. However, this is not limiting. The control unit 80 may be configured not to terminate tuning of the frequency band Fb using the tuner 60B even when tuning of the frequency band Fb using the tuner 60A results in the acquisition of tuning information S1 for the currently selected frequency band Fb using the tuner 60B. In this case, the control unit 80 waits for the arrival of an NIT or a no-signal notification from the TS processing unit 20A2. For example, when the control unit 80 receives an NIT from the TS processing unit 20A2, the control unit 80 generates tuning information S1 based on the descriptor Ds included in the received NIT and registers the generated tuning information in the management table Tb.

[0135] Furthermore, in broadcast signal receiving device 102 according to the second embodiment of the present disclosure, control unit 80 is configured to terminate tuning of frequency band Fb using tuner 70A when tuning of frequency band Fb using tuner 60A results in the acquisition of tuning information S1 for the currently selected frequency band Fb using tuner 70A. However, this is not limiting. Control unit 80 may be configured not to terminate tuning of frequency band Fb using tuner 70A even when tuning of frequency band Fb using tuner 60A results in the acquisition of tuning information S1 for the currently selected frequency band Fb using tuner 70A. In this case, control unit 80 waits for the arrival of an NIT or a no-signal notification from TS processing unit 20B1. For example, when control unit 80 receives a no-signal notification from TS processing unit 20B1, control unit 80 generates tuning information S2 indicating "no broadcast signal" and registers it in management table Tb.

[0136] The above-described embodiments should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0137] Each process (each function) in the above-described embodiments is realized by a processing circuit including one or more processors. The processing circuit may be configured as an integrated circuit or the like that combines one or more memories, various analog circuits, and various digital circuits in addition to the one or more processors. The one or more memories store programs (instructions) that cause the one or more processors to execute each of the processes. The one or more processors may execute each of the processes according to the program read from the one or more memories, or according to a logic circuit pre-designed to execute each of the processes. The processor may be various processors suitable for computer control, such as a central processing unit (CPU), a graphics processing unit (GPU), a digital signal processor (DSP), a field programmable gate array (FPGA), and an application-specific integrated circuit (ASIC). Note that the physically separate processors may cooperate with each other to execute each of the processes. For example, the processors mounted on a plurality of physically separated computers may cooperate with each other to execute the above processes via a network such as a LAN (Local Area Network), a WAN (Wide Area Network), the Internet, etc. The program may be installed into the memory from an external server device or the like via the network, or may be distributed in a state stored on a recording medium such as a CD-ROM (Compact Disc Read Only Memory), a DVD-ROM (Digital Versatile Disc Read Only Memory), or a semiconductor memory, and installed into the memory from the recording medium.

[0138] The above description includes the following additional features. [Appendix 1] A broadcast signal receiving device including a tuner capable of receiving a broadcast signal, a processing circuit; a storage unit that stores a management table indicating a plurality of frequency bands to be selected in a channel scan; The processing circuitry performing a tuning process for tuning into the frequency band using the tuner; registering channel selection information indicating the presence or absence of the broadcast signal corresponding to the selected frequency band in the management table; The processing circuit selects the frequency band for which the channel selection information is not registered in the management table. [Explanation of symbols]

[0139] 10, 10A, 10B tuner 11 Receiving unit 12 Demodulation section 20, 20A, 20A, 20A2, 20B, 20B1, 20B2 TS processing section 30 Content Processing Section 40,80 Control unit 50 Storage section 60, 60A, 60B tuner 62 Demodulation section 70, 70A, 70B tuner 72 Demodulation section 101, 102 Broadcast signal receiving device 111 Display device 201 Broadcast signal transmitter 301 Broadcasting System Lt Channel List Tb Management Table G1 display screen

Claims

1. A channel scanning method for a broadcast signal receiving device having a tuner capable of receiving a broadcast signal, comprising: the broadcast signal receiving device includes a storage unit that stores a management table indicating a plurality of frequency bands to be selected in a channel scan; The channel scanning method includes: a step of performing a tuning process to tune into the frequency band using the tuner; registering tuning information indicating the presence or absence of the broadcast signal corresponding to the selected frequency band in the management table; In the step of performing the channel selection process, the frequency band for which the channel selection information is not registered in the management table is selected.

2. the storage unit stores, as the management table, a first management table in which first channel selection information indicating whether or not the broadcast signal conforming to a transmodulation system is present can be registered; 2. The channel scanning method of claim 1, wherein in the step of registering the tuning information in the management table, the first tuning information corresponding to a frequency band other than the first frequency band among the plurality of frequency bands is generated based on an NIT included in the broadcast signal of the first frequency band among the plurality of frequency bands, and the generated first tuning information is registered in the first management table.

3. the storage unit further stores, as the management table, a second management table in which second channel selection information indicating whether or not the broadcast signal of the terrestrial digital broadcasting conforming to a pass-through system is present, 3. The channel scanning method of claim 2, wherein in the step of registering the tuning information in the management table, the second tuning information corresponding to a frequency band other than the first frequency band among the plurality of frequency bands is generated based on the NIT, and the generated second tuning information is registered in the second management table.

4. the tuner is capable of receiving the broadcast signal transmitted in accordance with a transmodulation method and the broadcast signal of a terrestrial digital broadcast transmitted in accordance with a pass-through method; 4. The channel scanning method according to claim 3, wherein in the step of performing the channel selection process, the broadcast signal transmitted according to a transmodulation method is received in priority over the broadcast signal of terrestrial digital broadcast transmitted according to a pass-through method.

5. the broadcast signal receiving device includes a plurality of tuners capable of receiving the broadcast signals transmitted in accordance with a transmodulation system; 5. A channel scanning method according to claim 1, wherein in the step of performing the channel selection process, selection is started from a plurality of the frequency bands corresponding to the plurality of tuners, respectively, and selection of the frequency bands is performed in parallel using the plurality of tuners.

6. 6. The channel scanning method of claim 5, wherein in the step of performing the channel selection process, if the channel selection information for the second frequency band is obtained by selecting a third frequency band using a second tuner of the plurality of tuners while selecting a second frequency band using a first tuner of the plurality of tuners, the channel selection for the second frequency band using the first tuner is terminated.

7. The channel scanning method further comprises: creating a channel list indicating a correspondence relationship between the channels of the broadcast signals and the frequency bands assigned to the channels based on the management table in which the channel selection information is registered; 5. The channel scanning method according to claim 1, further comprising: after creating the channel list, performing a preliminary tuning process of tuning into all of the plurality of frequency bands using the tuner.

8. a tuner capable of receiving broadcast signals; a storage unit that stores a management table indicating a plurality of frequency bands to be selected in a channel scan; a tuning unit that performs tuning processing to select the frequency band using the tuner; a registration unit that registers, in the management table, channel selection information indicating the presence or absence of the broadcast signal corresponding to the frequency band selected by the channel selection unit; The tuning unit tunes to the frequency band for which tuning information is not registered in the management table.

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