JP5074705B2 - Receiving device and receiving method, etc. - Google Patents

Description

  The present application relates to a technical field such as a receiving device that is mounted on a mobile body and receives broadcast data broadcast on different channels for each of a plurality of broadcast areas.

  Terrestrial digital broadcasting using a UHF (Ultra High Frequency) band of terrestrial waves has been started as next-generation broadcasting that replaces conventional terrestrial television broadcasting (terrestrial analog television broadcasting). This broadcast is characterized by high image quality, high sound quality, realization of data broadcasting, and the like, compared with conventional terrestrial television broadcasts, and its receiving devices are currently spreading.

  In Japan, ISDB-T (Integrated Services Digital Broadcasting-Terrestrial) standard is adopted for terrestrial digital television broadcasting. This standard uses OFDM (Orthogonal Frequency Division Multiplexing) as a modulation method, and divides one carrier (carrier) into a number of subcarriers (subcarriers) and uses the orthogonality of digitally modulated signals. By generating a modulation signal by overlapping a part on the frequency axis so that the signal does not interfere with adjacent subcarriers, wideband transmission is realized with improved frequency utilization efficiency. Note that different modulation schemes can be used for the modulation of each subcarrier.

  In the ISDB-T, a large number (for example, 5617) of subcarriers are divided into 13 segments, 12 of which are broadcasts for fixed reception, and the remaining 1 segment is 1 segment (one segment) broadcast. It is assigned to broadcasting for mobiles called. In broadcasting for fixed reception, in order to realize high image quality, for example, the modulation method is 64QAM (Quadrature Amplitude Modulation), the convolutional coding rate is 7/8, and the video compression method is MPEG2 (Moving Picture Experts Group 2). However, if the receiving device is placed in a movable environment where the reception state changes frequently, it is easily affected by multipath fading and performs stable reception. It ’s difficult. On the other hand, in one-segment broadcasting, for example, the modulation method is QPSK (Quadrature Phase Shift Keying), the convolutional coding rate is 2/3, and the video compression is H.264. H.264 makes it possible to receive a stable broadcast in such a mobile environment, although the image quality is low but the tolerance to data errors is increased.

  Conventionally, there are many receivers that can be mounted on mobile bodies such as automobiles, which can receive broadcasts for fixed reception. Recently, in order to start one-segment broadcasts, this one-segment broadcast has been started. The response is progressing.

For example, Patent Document 1 discloses a receiving apparatus that supports both types of broadcasting. This receiving device separates the received ODFM signal into a fixed reception broadcast signal and a one-segment broadcast signal, and when the reception quality of the ODFM signal is good, the fixed reception broadcast signal is sent to a display device or the like. If the reception quality is not good, a one-segment broadcast signal is output. As a result, high image quality and a wide service area can be secured.
JP 2005-223549 A

  By the way, in terrestrial digital television broadcasting, even in the same broadcasting station (for example, NHK Sogo / Tokyo), broadcasting is performed on different channels (for example, one channel is assigned a frequency band of 6 MHz). In many cases, this method (Multi-Frequency Network) is adopted. For example, broadcast on a parent station (for example, the Tokyo Tower (Broadcasting Station) in Minato-ku, Tokyo) and a relay station (for example, a broadcasting station in Hiratsuka City, Kanagawa Prefecture, or a broadcasting station in Shibukawa City, Gunma Prefecture) For example, the reception sensitivity of broadcast data broadcasted on the Tokyo Tower channel in Minato-ku, Tokyo, which is the master station, decreases as it moves away from Tokyo, while the relay station, Gunma Receiving sensitivity of broadcast data broadcast on the channel of a broadcasting station in Shibukawa City in the prefecture decreases as the distance from Gunma Prefecture increases.

  Therefore, for example, when a mobile body such as an automobile equipped with a receiving device that selects a channel broadcast from the Tokyo Tower in Minato-ku, Tokyo, which is the master station, moves from Tokyo to Gunma Prefecture, on the way Thus, unless the channel is switched from a broadcasting station in Shibukawa City, Gunma Prefecture, which is a relay station, it is difficult to receive broadcast data, and it is difficult for the user to view the contents of the broadcast data. On the other hand, when it becomes difficult for the user to view the content of the broadcast data, the user may switch the channel himself / herself, which is troublesome for the user.

  The present application has been made in view of the above points, and an example of the problem is to provide a receiving device, a receiving method, and the like that can switch to a more appropriate channel without the user being aware of it. .

In order to solve the above-described problem, the invention described in claim 1 is a receiving device that is mounted on a mobile body and receives broadcast data broadcast on a different channel for each of a plurality of broadcast areas. Channel setting means for setting a channel for reception; selection output means for selectively outputting any one of the plurality of types of broadcast data in the channel set by the channel setting means; and Position information acquisition means for acquiring position information indicating the current position of the moving object, and whether or not the current position of the moving object indicated in the position information has changed from one area divided by administrative division to another area Position determination means for determining the broadcast data of the image quality other than the lowest image quality from the plurality of types of image quality by the selection output means. In the state, when it is determined that the reception sensitivity of the broadcast data of the image quality is lower than the threshold, the channel setting means is a case where the current position of the mobile body is changed from the one area to the other area. Even if the channel is not switched, the selection output means selectively outputs broadcast data having an image quality lower than the image quality of the broadcast data that has been selected and output. When it is determined that the reception sensitivity of the broadcast data with the lowest image quality has become lower than a threshold value in the state where is selected and output, and it is determined that the one area has changed to another area, the channel setting means And switching from the channel corresponding to the one region to the channel corresponding to the other region.

The invention according to claim 6 is a receiving method for receiving broadcast data broadcast on a different channel for each of a plurality of broadcast areas, the step of setting a channel for receiving the broadcast data, and the setting A step of selectively outputting any one of a plurality of types of broadcast data of the image quality in the channel; a step of acquiring position information indicating a current position of the moving body; and a movement indicated by the position information A step of determining whether the current position of the body has changed from one region divided by administrative divisions to another region, and broadcast data having an image quality other than the lowest image quality among the plurality of types of image quality is selectively output. When the reception sensitivity of the broadcast data of the image quality is determined to be lower than the threshold value in the state where the current position of the mobile object is changed from the one area to the other area Even when the channel is not switched, the step of selecting and outputting broadcast data with a lower image quality than the image quality of the broadcast data that has been selectively output, and the state where the broadcast data with the lowest image quality is selectively output When the reception sensitivity of the broadcast data with the lowest image quality is determined to be lower than the threshold value and it is determined that the one region has changed to another region, the channel corresponding to the one region is changed to the other channel. And switching to the channel corresponding to the area.

The invention of the reception processing program according to claim 7 sets a channel for receiving broadcast data on a computer mounted on a mobile body and receiving broadcast data broadcast on different channels for each of a plurality of broadcast areas. Channel setting means, selection output means for selectively outputting any one of a plurality of types of broadcast data in the channel set by the channel setting means, position information indicating the current position of the mobile body And a position determination means for determining whether or not the current position of the moving body indicated by the position information has changed from one area divided by administrative divisions to another area. A state in which broadcast data of an image quality other than the lowest image quality is selected and output by the selection output means from among the plurality of types of image quality When the reception sensitivity of the broadcast data of the image quality is determined to be lower than the threshold value, the channel setting means is configured when the current position of the mobile body is changed from the one area to the other area. Even if the channel is not switched, the selection output means selectively outputs broadcast data having an image quality lower than the image quality of the broadcast data that has been selected and output. When it is determined that the reception sensitivity of the broadcast data with the lowest image quality has become lower than a threshold value in the state where is selected and output, and it is determined that the one area has changed to another area, the channel setting means And switching from the channel corresponding to the one region to the channel corresponding to the other region.

An invention of a recording medium according to an eighth aspect is characterized in that the reception processing program according to the seventh aspect is recorded in a computer-readable manner.

  Hereinafter, the best embodiment of the present application will be described in detail with reference to the drawings. In addition, embodiment described below is embodiment at the time of applying this application with respect to the digital terrestrial television receiver mounted in a motor vehicle.

[1. Configuration of digital terrestrial television receiver]
First, the configuration of the terrestrial digital television receiver S (an example of the receiving apparatus of the present application) according to the present embodiment will be described with reference to FIG.

  FIG. 1 is a diagram illustrating an example of a schematic configuration of a terrestrial digital television receiver S according to the present embodiment. In the following description, the digital terrestrial television receiver is simply referred to as a TV receiver.

  As shown in FIG. 1, the TV receiver S includes a tuner unit 11, a demodulation / decoding unit 12, a separation unit 13, a 1-segment decoder unit 14, a 12-segment decoder unit 15, and an example of a selection output unit. Switch unit 16, video processing unit 17, display 18, audio processing unit 19, speaker 20, GPS (Global Positioning System) unit 21, operation unit 22, and storage unit 23 as an example of a storage unit. And a system control unit 24 as an example of a channel setting unit, a position information acquisition unit, a position determination unit, and a reception sensitivity determination unit, and ISDB broadcast on a predetermined channel from a broadcasting station (not shown) -T standard broadcast data (broadcast signal) is received and 1 segment broadcast for mobile reception and 12 segment broadcast for fixed reception (HDTV with high image quality and high sound quality ( High Definition TeleVision) and standard SDTV (Standard Definition TeleVision) are output. As an apparatus with such a configuration, for example, it can be applied to a car navigation apparatus equipped with a TV receiver.

  In one-segment broadcasting, the image quality of the video is low (low image quality) (for example, video compression method H.264, frame speed 15, resolution 320 × 240, etc.), but the tolerance to data errors (an example of quality) is high. (For example, modulation scheme QPSK, coding rate 2/3, etc.). On the other hand, in 12-segment broadcasting, the image quality of the video is high (high image quality) (for example, the moving image compression method is MPEG2 Video, the frame rate is 30, the resolution is 1440 × 1080, etc.), and the tolerance to data errors is low (the modulation method is 64QAM). The coding rate is 7/8, etc.). Note that the program contents of 1-segment broadcast and 12-segment broadcast on the same channel are basically the same.

  The tuner unit 11 tunes to the frequency band of the channel designated by the control of the system control unit 24, receives broadcast data broadcast in the frequency band via the antenna AT1, and generates an intermediate frequency signal. The frequency signal is output to the demodulator / decoder 12.

  The demodulation / decoding unit 12 performs A / D conversion, orthogonal demodulation processing, fast Fourier transform, carrier demodulation, Viterbi decoding, transport stream reproduction, Reed-Solomon decoding, and the like on the intermediate frequency signal supplied from the tuner unit 11. The transport stream TS is generated to output the stream TS to the separation unit 13. The transport stream TS is a signal sequence in which TS packets are continuous. The TS packet includes a packet header portion and a payload portion (TS payload). The PSI (program identification information) of the payload portion is included in the transport stream TS. The NIT includes a TS identification code (unique identifier assigned to each transport stream TS). The TS identification code is unique to each broadcasting station, for example, and is supplied from the demodulation / decoding unit 12 to the system control unit 24, for example.

  The separation unit 13 separates the transport stream TS supplied from the demodulation / decoding unit 12 into 1-segment broadcast stream and 12-segment broadcast stream for each TS packet, and the 1-segment broadcast transport stream TS is 1 segment. The transport stream TS for 12 segment broadcasting is output to the decoder unit 14 to the 12 segment decoder unit 15, respectively.

  The 1-segment decoder unit 14 separates the transport stream TS for 1-segment broadcasting supplied from the separating unit 13 into a video stream and an audio stream, and each stream is set to a predetermined standard (for example, video is H.264, audio Is converted into video data and audio data (hereinafter simply referred to as video / audio data) based on MPEG4-AAC (Advanced Audio Coding) or the like, and these signals are output to the switch unit 16.

  The 12-segment decoder unit 15 separates the transport stream TS for 12-segment broadcasting supplied from the separation unit 13 into a video stream and an audio stream, and each stream is set to a predetermined standard (for example, video is MPEG2-Video, audio Are converted into video / audio data based on MPEG2-AAC, etc., and these signals are output to the switch unit 16.

  The 1-segment decoder unit 14 and the 12-segment decoder unit 15 supply information (for example, signal amplitude) indicating the reception sensitivity of the video / audio data included in the broadcast data to the system control unit 24.

  Based on the control by the system control unit 24, the switch unit 16 is one of the video / audio data supplied from the 1-segment decoder unit 14 and the video / audio data supplied from the 12-segment decoder unit 15. Audio data is selectively output (video data is output to the video processing unit 17 and audio data is output to the audio processing unit 19).

  The video processing unit 17 performs D / A conversion, gamma correction, brightness / contrast adjustment, etc. on the video data supplied from the switch unit 16 to generate a video signal, and outputs this signal to the display 18. It has become.

  The display 18 displays the video on the screen by driving the display panel based on the video signal supplied from the image processing unit 17.

  The audio processing unit 19 generates an audio signal by performing D / A conversion, amplification, and the like on the audio data supplied from the switch unit 16, and outputs the signal to the speaker 20.

  The speaker 20 outputs sound as a sound wave having an audible frequency by driving the cone to vibrate based on the sound signal supplied from the sound processing unit 19.

  The GPS unit 21 includes a GPS (Global Positioning System) receiver or the like, receives navigation radio waves output from GPS satellites arranged in the satellite orbit and orbiting the earth via the antenna AT2, and based on the received signals. Thus, current position information (longitude and latitude) is detected, and an area code corresponding to the current position information is supplied to the system control unit 24.

  The storage unit 22 includes, for example, a hard disk drive, a nonvolatile memory such as an EPROM or an EEPROM, and includes various data and programs, an association table of area codes and area identification codes, area identification codes and TS identifications A code association table, a TS identification code / channel association table, and the like are stored in advance.

  FIG. 2 is a diagram illustrating a part of the contents of each table stored in the storage unit 22. FIG. 2A illustrates an example of the association table 1 such as an area code and a region identification code. B) shows an example of an association table 2 for area identification codes and TS identification codes, and FIG. 2C shows an example of an association table 3 for TS identification codes and channel numbers.

  Here, the area code is composed of a 2-digit prefecture code and a 3-digit city code. For example, when the area code is "11201", the upper "11" is the prefecture code (JISX0401 standard (Japan Specified by one of the industrial standards), and the lower “201” indicates the municipal code (specified by the JISX0402 standard (one of the Japanese Industrial Standards)) and is unique for each municipality. Yes. The area identification code is a unique identifier for each area divided in advance, and in this embodiment, this area is set as an administrative division such as Tokyo, Saitama, Kanagawa, or the like. Furthermore, one zip code is assigned to each area code. Since zip codes are further subdivided than municipalities, there are cases where a plurality of zip codes are associated with one area code (the same zip code is assigned to each of a plurality of area codes). However, in this embodiment, one representative zip code is assigned in this case. Note that the zip code corresponding to the current position is set in the TV receiver S, and the TV receiver S is able to select the weather forecast information, the election bulletin, etc. of the area corresponding to the set zip code. The data broadcasting content can be acquired.

  Therefore, the table 1 shown in FIG. 2A can identify which region the current position corresponds to (in other words, in which region), and the zip code corresponding to the current position can be specified. Can be identified.

  Also, in the table 2 shown in FIG. 2B, a plurality of TS identification codes are associated with each region (region identification code). Thereby, it is possible to specify a plurality of broadcasting stations (TS names) broadcast in a certain area (for example, Saitama Prefecture) and TS identification codes corresponding to the transport stream TS broadcasted from these stations. Then, a TS identification code corresponding to the transport stream TS included in the currently received (tuned) broadcast data can be specified among the plurality of transport streams TS.

  Also, in the table 3 shown in FIG. 2C, a plurality of channel numbers (an example of information indicating the channel) are associated with each region and TS identification code (one channel for a certain region). For example, Saitama Prefecture has a channel 27 corresponding to a frequency band broadcast from Tokyo Tower in Minato-ku, Tokyo, which is the parent station, and Kanagawa Prefecture, which is a relay station. Channel 19 corresponding to the frequency band broadcast from the broadcasting station in Hiratsuka City, channel 37 corresponding to the frequency band broadcasting from the broadcasting station in Shibukawa City, Gunma Prefecture, which is a relay station, and the like are associated with each other. Note that the contents of broadcast data broadcast in the frequency bands corresponding to the plurality of channels are the same.

  Furthermore, each of these channels is associated with a number indicating priority (an example of information indicating priority). In Saitama Prefecture shown in FIG. Is associated with “1”, channel 19 with “2”, and channel 37 with “3”. Here, the lower the number indicating the priority (the closer to “1”), the higher the priority, and the higher the priority, the higher the broadcast data reception sensitivity in the area.

  The operation unit 23 includes various buttons and the like, and outputs operation contents by a user (driver, passenger, etc.) to the system control unit 24 as an instruction signal. Based on this instruction signal, the system control unit 24 performs control such as power ON / OFF and channel switching.

  The system control unit 24 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and the like, and the CPU stores various control programs (including a reception processing program) stored in the ROM or the like. By executing the reading, the entire TV receiver S is controlled as a whole, and functions as a channel setting means, position information acquisition means, position determination means, reception sensitivity determination means, and zip code setting means.

  Specifically, the system control unit 24 sets (tunes) a channel for receiving broadcast data in accordance with, for example, an instruction signal from the operation unit 23 and designates a frequency band for the tuner unit 11.

  Then, the system control unit 24 acquires an area code corresponding to the current position information from the GPS unit 21 (an area code corresponding to the municipality where the current position is included), and the current position of the car is preliminarily classified. If it is determined whether it has changed (moved) from another area (eg, Saitama Prefecture) to another area (Gunma Prefecture), and if it is determined that it has changed from one area to another area, it corresponds to that one area The channel (corresponding to the channel that has been selected until now) is switched to the channel corresponding to other regions. At this time, when a plurality of channel numbers are registered in the table 3 in association with the other regions, the system control unit 24 selects the channel corresponding to the channel number having the highest priority among them (in other words, It is desirable to switch to the channel having the highest reception sensitivity among the plurality of channels.

  Further, the system control unit 24 acquires information indicating the reception sensitivity of the broadcast data from the 1-segment decoder unit 14 and the 12-segment decoder unit 15, and the reception sensitivity of the broadcast data being received (channel selection) becomes lower than the threshold value. Judgment is made whether or not. From this, the system control unit 24 determines that the reception sensitivity of the broadcast data broadcast on the channel corresponding to one region has become lower than the threshold, and determines that the region has changed from one region to another region. For the first time, as described above, a channel corresponding to one region is switched to a channel corresponding to another region (in other words, even if the region changes from one region to another region, If the reception sensitivity of the broadcast data broadcast on the corresponding channel is higher than the threshold value, the channel switching setting is not performed.

  Furthermore, the system control unit 24 determines whether or not the reception sensitivity of the video / audio data has become lower than the threshold value in a state where the video / audio data supplied from the one-segment decoder unit 14 is selectively output by the switch unit 16. Is determined based on the information indicating the reception sensitivity from the one-segment decoder unit 14, it is determined that the reception sensitivity is lower than the threshold value, and it is determined that the change from one region to another region is performed. As described above, it may be configured to switch from a channel corresponding to one region to a channel corresponding to another region. For example, when the system control unit 24 determines that the reception sensitivity of the video / audio data is lower than the threshold value in a state where the video / audio data supplied from the 12-segment decoder unit 15 is selectively output by the switch unit 16 First, the switch unit 16 is controlled so as to selectively output the video / audio data supplied from the one-segment decoder unit 14, and the reception sensitivity is still lower than the threshold value. Only when it is determined that the area has changed to one area, the channel corresponding to one area is switched to the channel corresponding to another area as described above.

  The reception processing program of the present application is stored and stored in a predetermined server connected to the Internet, for example, and is downloaded from the server to the TV receiver S through a communication unit (not shown) and stored in the storage unit 23. Alternatively, it may be configured to be read from a recording medium such as a CD-ROM into the TV receiver S via a drive or the like and stored in the storage unit 23.

[2. Operation of digital terrestrial television receiver]
Next, the operation of the TV receiver S will be described separately in the first embodiment and the second embodiment.

Example 1
First, Example 1 will be described with reference to FIG.

  FIG. 3 is a flowchart illustrating the switching process of the system control unit 24 according to the first embodiment. 3 is started when the power of the TV receiver S is turned on, for example, and the above-described tables 1 to 3 (FIGS. 2A to 2C) are read from the storage unit 22 into the RAM. (The same applies to Example 2). In addition, when the user performs a channel switching operation by operating the operation unit 23 while the processing illustrated in FIG. 3 is being performed, the system control unit 24 follows the instruction signal or the like from the operation unit 23. Switching to the channel corresponding to the channel is set (the same applies to the second embodiment).

  In step S <b> 1 illustrated in FIG. 3, the system control unit 24 acquires (stores in RAM) an area code from the GPS unit 21.

  Next, the system control unit 24 compares the area code acquired this time with the area code previously acquired and stored in the RAM (hereinafter referred to as “last area code”) to determine whether or not they are different. (Step S2). As a result of this determination, if the area code and the last area code acquired this time are not different (match) (step S2: N), the last area code is maintained and the process returns to step S1.

  On the other hand, when the area code acquired this time is different from the last area code (step S2: Y), the system control unit 24 acquires an area identification code corresponding to the area code acquired this time with reference to Table 1 ( In step S3), the last area code is updated to the area code acquired this time (step S4).

  Next, the system control unit 24 acquires the postal code (representative postal code) corresponding to the area code acquired this time from the table 1, and acquired the postal code (representative postal code) that was set before. Switching to the zip code is set (step S5). As a result, even if the user does not know the postal code corresponding to the current position (usually, the user rarely knows the postal code corresponding to the current position), the automatic switching of the postal code makes it possible for the user to The TV receiver S can acquire data broadcast contents such as weather forecast information and election bulletins and present (display or output sound) to the user, which is very convenient for the user. In addition, as will be described later (in step S6), when the region identification code acquired this time is different from the last region identification code (that is, the region has changed from one region to another region) as will be described later (in step S6). You may make it.

  Next, the system control unit 24 compares the area identification code acquired this time with the area identification code previously acquired and stored in the RAM (hereinafter referred to as “last area identification code”), and whether or not they are different. That is, it is determined whether or not the current position of the car has changed (moved) from one area (for example, Saitama Prefecture) to another area (Gunma Prefecture) (step S6). As a result of the determination, when the area identification code acquired this time matches the last area identification code (that is, the area has not changed from one area to another area) (step S6: N), the last area identification code is maintained. Then, the process returns to step S1.

  On the other hand, when the area identification code acquired this time and the last area identification code are different (that is, changed from one area to another area) (step S6: Y), the system control unit 24 is currently receiving data. The TS identification code corresponding to the transport stream TS included in the (selected channel) broadcast data is acquired from, for example, the demodulation / decoding unit 12, and the last area identification code is updated to the area identification code acquired this time (step S7). .

  Next, the system control unit 24 determines whether or not the acquired TS identification code is included in the TS identification code associated with the area identification code acquired this time with reference to the table 2 (step S8). . As a result of the determination, if the acquired TS identification code is not included (step S8: N), the process returns to step S1.

  On the other hand, when the acquired TS identification code is included (that is, the acquired TS identification code is registered in the table 2 in association with the area identification code acquired this time) (step S8: Y). The system control unit 24 determines whether or not a plurality of channel numbers are associated with the acquired TS identification code and the currently acquired area identification code (corresponding to another area) with reference to Table 3. (Step S9). If it is determined that only one channel number is associated instead of a plurality of channel numbers (step S9: N), the system control unit 24 searches for a frequency band corresponding to the channel number ( In step S10), if reception is possible in the searched frequency band (step S11: Y), the channel corresponding to the searched channel number is set to be switched (step S12), indicating that the channel has been automatically switched. While displaying on the display 18, this frequency band is designated with respect to the tuner part 11, and it returns to step S1. On the other hand, if reception is not possible in the searched frequency band (step S11: N), the system control unit 24 displays that fact on the display 18, returns to step S10, and repeats the same processing.

  On the other hand, when a plurality of channel numbers are associated (that is, a plurality of channel numbers are associated with the other regions and registered in the table 3) (step S9: Y), the system control unit 24 searches the frequency band in order from the highest priority among the plurality of channel numbers registered in the table 3 (for example, when the other region is Gunma Prefecture shown in FIG. The frequency bands are searched in the order of channel 37 → channel 27 → channel 47 → channel 19 (this eliminates the need to seek all frequency bands) (step S13), and reception is possible in the searched frequency band (mostly). If reception is possible in a frequency band corresponding to a channel number having a high priority, only one search is required (step S1). : Y), switching to the channel corresponding to the searched channel number is set (step S12), the fact that the channel is automatically switched is displayed on the display 18, and this frequency band is designated to the tuner unit 11. Return to step S1. On the other hand, if reception is not possible in all the searched frequency bands (step S14: N), the system control unit 24 displays that fact on the display 18, returns to step S13, and repeats the same processing.

  As described above, according to the first embodiment, the area code corresponding to the current position information is acquired from the GPS unit 21, and the current position of the vehicle specified by the area code is preliminarily divided into one region ( For example, if it is determined by the region identification code whether it has changed (moved) from Saitama Prefecture to another region (Gunma Prefecture), and if it is determined that it has changed from one region to another region, Since it is configured to switch from a corresponding channel to a channel corresponding to another region, the user can automatically switch to a more appropriate channel without being aware of it, and the user can easily change the content of the broadcast data without feeling uncomfortable. Can watch.

  Further, a plurality of channel numbers are registered in the table 3 in association with each region (region identification code), and a channel corresponding to the channel number having the highest priority among them (in other words, among the plurality of channels). (The channel with the highest reception sensitivity) is set so as to be switched, so that the user can view the content of the broadcast data more comfortably.

  In step S10 and step S13, the system control unit 24 determines whether or not the reception sensitivity of the broadcast data broadcast on the currently set channel is lower than the threshold value. If it is configured to perform the above frequency band search (that is, when the reception sensitivity is sufficient, the search is not performed and the currently set frequency band of the channel is maintained), and automatic channel switching is performed more efficiently. be able to.

(Example 2)
Next, Example 2 will be described with reference to FIG.

  FIG. 4 is a flowchart illustrating the switching process of the system control unit 24 according to the second embodiment.

  In step S21 shown in FIG. 4, the system control unit 24 determines whether or not the 12-segment broadcast is selected and output by the switch unit 16, and the broadcast data related to the 12-segment broadcast is selected and output (that is, 12). When the video / audio data supplied from the segment decoder unit 15 is selected and output (step S21: Y), the process proceeds to step S22, and the broadcast data related to the 12-segment broadcast is not selectively output (that is, If the video / audio data supplied from the one-segment decoder unit 14 is selected and output (step S21: N), the process proceeds to step S25.

  In step S22, the system control unit 24 acquires information indicating the reception sensitivity from the 12-segment decoder unit 15, determines whether the reception sensitivity of the 12-segment broadcast is lower than a threshold value (monitors until lower than the threshold value), If lower than the threshold (step S22: Y), the process proceeds to step S23.

  In step S23, the system control unit 24 determines whether or not the one-segment broadcast transport stream TS is included in the currently received broadcast data (step S23: Y). A selection switching signal is output to the switch unit 16 so as to selectively output the video / audio data supplied from the one-segment decoder unit 14 (step S24). That is, when the reception sensitivity of 12-segment broadcasting deteriorates, switching to video and audio output of 1-segment broadcasting is performed. On the other hand, when the currently received broadcast data does not include the transport stream TS for 1-segment broadcasting (step S23: N), the process proceeds to step S28.

  On the other hand, in step S25, the system control unit 24 acquires information indicating the reception sensitivity from the one-segment decoder unit 14, determines whether the reception sensitivity of the one-segment broadcast is lower than the threshold value, and if lower than the threshold value, (Step S25: Y), the process proceeds to Step S28, and if not lower than the threshold value (Step S25: N), the process proceeds to Step S26.

  In step S26, the system control unit 24 acquires information indicating the reception sensitivity from the 12-segment decoder unit 15, determines whether the reception sensitivity of the 12-segment broadcast is higher than the threshold, and if not higher than the threshold ( Step S26: N), the process returns to Step S25, and if it is higher than the threshold value (Step S26: Y), the switch unit 16 is selected to selectively output the video / audio data supplied from the 12-segment decoder unit 15. A switching signal is output (step S27). That is, when the reception sensitivity of the 12-segment broadcast is improved, it is switched to the video and audio output of the 12-segment broadcast of the 12-segment broadcast.

  Then, in the channel switching process shown in step S28, the process proceeds to the switching process shown in FIG. 3 (that is, the process proceeds to step S1), and the same process as in the first embodiment is performed. As a result, it is possible to switch from a channel corresponding to one region to a channel corresponding to another region for the first time when the reception sensitivity is low even in one-segment broadcasting. In Example 2, instead of returning to Step S1 in Example 1, the process returns to Step S21 shown in FIG.

  As described above, according to the second embodiment, when the reception sensitivity of the 12-segment broadcast is lower than the threshold in the state where the high-quality broadcast data related to the 12-segment broadcast is selected and output, the first segment Only when it is determined that the reception sensitivity is still lower than the threshold and it is determined that the area has changed from one area to another area, so that low-quality broadcast data related to broadcasting is selectively output. Since the configuration is such that the channel corresponding to one region is switched to the channel corresponding to another region, the convenience for the user can be improved (the usability is improved).

  In the above embodiment, as an example of the region, Tokyo, Saitama Prefecture, Gunma Prefecture, etc., that is, divided by prefecture (administrative district), the range of the region and the range of the broadcast area are When the current location changes from one region to another, it is possible to switch to a channel (frequency band) that suits the region more appropriately, and the data including the above table The capacity can be minimized, and the table search processing time can be shortened (search performance can be improved). However, the region may be classified by a wider region (for example, Kanto, Tohoku, Kansai region, etc.) or not by a prefecture, or by a narrow region (for example, a municipality). good.

  Further, the regional divisions may be set as appropriate according to the range of the broadcast area without being limited to the administrative divisions. For example, the map is divided into small ranges specified by longitude and latitude (that is, divided into meshes), and the divided range (mesh range) is defined as the above-mentioned “region” (the divided mesh range is further subdivided) However, in this case, the construction of the database is difficult, the capacity thereof is increased, and the search performance is lowered. It is more advantageous to sort by prefecture.

  In the above embodiment, the present application is applied to a TV receiver mounted on an automobile as an example of a moving body. However, the present invention may be applied to, for example, a motorcycle or a ship, or a PDA (Personal Digital Assistant). The present invention may also be applied to mobile objects such as mobile terminals such as mobile phones.

  In the above embodiment, the present application is applied to terrestrial digital broadcasting. However, for example, the present application may be applied to other types of broadcasting such as Internet broadcasting (whether wired or wireless).

It is a figure which shows an example of schematic structure of the terrestrial digital television receiver S which concerns on this embodiment. FIG. 4 is a diagram illustrating a part of the contents of each table stored in a storage unit 22. 3 is a flowchart illustrating a switching process of a system control unit 24 according to the first embodiment. 10 is a flowchart illustrating a switching process of a system control unit 24 according to the second embodiment.

Explanation of symbols

11 tuner unit 12 demodulation / decoding unit 13 separation unit 14 1 segment decoder unit 15 12 segment decoder unit 16 switch unit 17 video processing unit 18 display 19 audio processing unit 20 speaker 21 GPS unit 22 operation unit 23 storage unit 24 system control unit S Terrestrial digital TV receiver (TV receiver)

Claims (8)

A receiver that is mounted on a mobile body and receives broadcast data broadcast on different channels for each of a plurality of broadcast areas,
Channel setting means for setting a channel for receiving the broadcast data;
Selection output means for selectively outputting any one of broadcast data of a plurality of types of image quality in the channel set by the channel setting means;
Position information acquisition means for acquiring position information indicating a current position of the mobile body;
Position determining means for determining whether or not the current position of the moving body indicated in the position information has changed from one area divided by administrative divisions to another area;
With
When it is determined that the reception sensitivity of the broadcast data having the image quality other than the lowest image quality is selected and output by the selective output unit among the plurality of types of image quality, the reception sensitivity of the broadcast data having the image quality is lower than a threshold value. The channel setting means does not switch the channel even when the current position of the mobile body is changed from the one area to the other area, and the selection output means does not perform the selection output. Select and output broadcast data with lower image quality than the data quality,
It is determined that the reception sensitivity of the broadcast data with the lowest image quality is lower than a threshold value in a state where the broadcast data with the lowest image quality is selectively output by the selection output means, and the region has changed from the one region to another region. When it is determined, the channel setting means switches from the channel corresponding to the one area to the channel corresponding to the other area, and the receiving apparatus is characterized in that it is set. The receiving device according to claim 1,
Storage means for storing information indicating a plurality of channels in association with each of the regions;
The channel setting means is determined that the reception sensitivity of the broadcast data with the lowest image quality is lower than a threshold value in a state where the broadcast data with the lowest image quality is selectively output by the selection output means, and from the one region When it is determined that the area has changed to another area, the receiving apparatus is configured to switch to a channel having the highest reception sensitivity among the plurality of channels corresponding to the other area. The receiving device according to claim 1,
Storing information indicating a plurality of channels in association with each of the regions, and further storing storage information indicating priority in association with each of the plurality of channels;
The channel setting means is determined that the reception sensitivity of the broadcast data with the lowest image quality is lower than a threshold value in a state where the broadcast data with the lowest image quality is selectively output by the selection output means, and from the one region When it is determined that the area has changed to another area, the receiving apparatus is configured to switch to a channel having the highest priority among the plurality of channels corresponding to the other area. The receiving apparatus according to any one of claims 1 to 3,
Broadcast data broadcast on different channels for each of the plurality of broadcast areas has the same content. The receiving apparatus according to any one of claims 1 to 4,
A zip code setting means for setting a zip code;
The zip code setting means determines that the reception sensitivity of the broadcast data with the lowest image quality is lower than a threshold value in a state where the broadcast data with the lowest image quality is selectively output by the selection output means, and the one area When it is determined that the area has changed to another area, the receiving apparatus is configured to switch from the zip code corresponding to the one area to the zip code corresponding to the other area. A receiving method for receiving broadcast data broadcast on a different channel for each of a plurality of broadcast areas,
Setting a channel for receiving the broadcast data;
A step of selectively outputting any one of the broadcast data of a plurality of types of image quality in the set channel;
Obtaining position information indicating a current position of the mobile body;
Determining whether the current position of the moving object indicated in the position information has changed from one area divided by administrative division to another area;
When it is determined that the reception sensitivity of the broadcast data with the image quality other than the lowest image quality among the plurality of types of image quality is selected and output, the current position of the mobile object Even when the region changes from the one region to the other region, the step of selectively outputting broadcast data having an image quality lower than the image quality of the broadcast data that has been selectively output without switching the channel;
When it is determined that the reception sensitivity of the broadcast data with the lowest image quality is lower than a threshold in the state where the broadcast data with the lowest image quality is selectively output, and it is determined that the one region has changed to another region. Switching from the channel corresponding to the one region to the channel corresponding to the other region;
A receiving method comprising: A computer mounted on a mobile unit that receives broadcast data broadcast on different channels for each of multiple broadcast areas.
Channel setting means for setting a channel for receiving the broadcast data;
Selective output means for selectively outputting any one of the broadcast data of a plurality of types of image quality in the channel set by the channel setting means,
Position information acquisition means for acquiring position information indicating a current position of the moving body; and
Functioning as position determination means for determining whether or not the current position of the moving body indicated in the position information has changed from one area divided by administrative division to another area,
When it is determined that the reception sensitivity of the broadcast data having the image quality other than the lowest image quality is selected and output by the selective output unit among the plurality of types of image quality, the reception sensitivity of the broadcast data having the image quality is lower than a threshold value. The channel setting means does not switch the channel even when the current position of the mobile body is changed from the one area to the other area, and the selection output means does not perform the selection output. Select and output broadcast data with lower image quality than the data quality,
It is determined that the reception sensitivity of the broadcast data with the lowest image quality is lower than a threshold value in a state where the broadcast data with the lowest image quality is selectively output by the selection output means, and the region has changed from the one region to another region. When it is determined, the channel setting means switches and sets the channel corresponding to the one region to the channel corresponding to the other region. A recording medium in which the reception processing program according to claim 7 is recorded so as to be readable by a computer.

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