JP2015082791A - Digital broadcast receiver and preset switching method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a digital broadcast receiver and a preset switching method which are capable of preventing presetting of an unnecessary channel which is much likely to become unreceivable soon, when automatically updating a preset memory.SOLUTION: The digital broadcast receiver includes: a scan processing unit 12 which scans channels except channels of the same area code as a current area code when the reception intensity of a channel being received at present falls to a prescribed value or lower; and a preset update unit 13 which stores receivable channels extracted by the scan, into a preset memory 10. When the preset memory 10 is automatically updated during movement of a vehicle across different broadcast areas because the reception intensity of a channel received in a broadcast area of a movement source is reduced, channels relating to the broadcast area of the movement source are not preset, and only channels relating to broadcast areas likely to be a movement destination are preset.

Description

  The present invention relates to a digital broadcast receiving apparatus and a preset switching method, and is particularly suitable for use in a digital broadcast receiving apparatus having a function of appropriately updating a registered channel of a preset memory with movement.

  In a vehicle-mounted digital broadcast receiver, if a vehicle moves across different broadcast areas, it cannot receive a digital broadcast of a channel that has been viewed. To solve this problem, a function is provided to start channel scan of all frequencies in the background and automatically update the registered channels in the preset memory when the reception intensity of the channel being viewed falls below a predetermined value. Yes.

  For example, as shown in FIG. 4, when moving from the broadcasting area in Fukushima Prefecture to the broadcasting area in Ibaraki Prefecture, the received intensity of the channel that was viewed up to the point beyond the border of Fukushima Prefecture is below a predetermined value. Therefore, the scan is performed and the registered channel of the preset memory is automatically updated.

  In this case, since scanning is performed at the prefectural border, some channels in Fukushima Prefecture may be scanned and preset even though they are away from Fukushima Prefecture. However, even if preset, the vehicle leaves the broadcasting area of Fukushima Prefecture, so that the preset channel cannot be received immediately.

  In addition, it is determined whether or not the frequency of the detected broadcasting station is the same as a specific frequency (for example, 1620 kHz of traffic information), and if it is determined to be the same, the frequency is not stored in the preset memory. A technique has been proposed (see, for example, Patent Document 1). According to this technology, it is possible to prevent the frequency of a traffic information broadcasting station having a dedicated switch from being stored in the preset memory, and to prevent the range of channel selection by the preset switch from being narrowed.

  By the way, for each broadcast area, area preset information indicating a list of receivable channels is stored in advance in the database, and the area preset information of the broadcast area corresponding to the current position of the vehicle is read and stored in the preset memory. There is also a technique called “area preset”. However, there is a problem that the accuracy of the area preset information is poor and there is a channel that cannot be received immediately after the preset, or that the preset channel cannot be received with the movement of the vehicle even in the same broadcast area.

JP-A-6-303108

  The present invention has been made in order to solve the above-described problems, and performs scanning in response to a decrease in reception intensity of a channel being viewed, and immediately updates a preset memory registered channel. It is an object of the present invention to prevent presetting of useless channels that are highly likely not to be received.

  In order to solve the above-described problems, in the present invention, when a channel reception intensity becomes a predetermined value or less, channels that can be received are excluded except for the channel having the same area code as that of the channel currently being received. Scanning is performed, and the receivable channels extracted by this are stored in the preset memory.

  According to the present invention configured as described above, when the vehicle is moving across different broadcast areas, the preset memory is automatically updated because the reception intensity of the channel received in the source broadcast area has decreased. The channels related to the source broadcast area are not preset, and only the channels related to the target broadcast area are preset. As a result, it is possible to prevent unnecessary channels from being preset with a high possibility that they cannot be received immediately as the vehicle moves.

It is a figure which shows the structural example of the digital broadcast receiver by this embodiment. It is a figure which shows the operation example of the digital broadcast receiver by this embodiment. It is a flowchart which shows the operation example of the digital broadcast receiver by this embodiment. It is a figure which shows the example of the scene which performs automatic update of a preset memory by the fall of receiving intensity.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram illustrating a configuration example of a digital broadcast receiving apparatus according to the present embodiment. In the configuration of the digital broadcast receiver shown in FIG. 1, an antenna 1 receives radio waves of digital broadcast. The tuner 2 selectively extracts a broadcast wave signal having a reception frequency matching a desired channel from the digital broadcast radio wave received by the antenna 1 and outputs the broadcast wave signal.

  The OFDM demodulator 3 demodulates the broadcast wave signal received by the tuner 2 by OFDM (Orthogonal Frequency-Division Multiplexing) to obtain a transport stream (hereinafter referred to as TS). The error correction unit 4 corrects errors generated in the transmission path for the TS demodulated by the OFDM demodulation unit 3.

  The demultiplexer unit 5 obtains an audio stream, a video stream, and a data stream by separating the multiplexed TS. Then, the demultiplexer unit 5 outputs the audio stream to the audio decoder unit 6, outputs the video stream to the video decoder unit 7, and outputs the data stream to the data decoder unit 8. Here, the data stream includes information about a channel such as a broadcast station name and a physical channel (reception frequency) of the broadcast station, and an area code indicating an area where the broadcast wave of the channel can be received.

  The audio decoder unit 6 decodes the input audio stream and outputs it as an audio signal. The video decoder unit 7 decodes the input video stream and outputs it as a video signal. The data decoder 8 decodes the input data stream and outputs it as control data.

  The channel switching unit 9 selects and switches a channel received by the tuner 2 in accordance with a user operation on an operation unit (not shown). The preset memory 10 stores information related to a plurality of receivable channels corresponding to a plurality of preset numbers. The preset memory 10 stores information on the physical channel and area code of the broadcast station for each preset number.

  When the user operates a preset selection button (not shown) of the operation unit to arbitrarily select any preset number, the channel switching unit 9 is stored in the preset memory 10 corresponding to the selected preset number. Is set as a receiving channel for the tuner 2.

  The reception strength determination unit 11 determines whether or not the reception strength of the channel currently being received by the tuner 2 is equal to or lower than a predetermined value. This is to determine whether or not the vehicle is moving across different broadcast areas. That is, if the vehicle is moving across different broadcast areas as shown in FIG. 4, the reception intensity of the channel that has been viewed until then decreases. Therefore, when the reception intensity becomes a predetermined value or less, it can be determined that the vehicle is moving from the current broadcast area to a different broadcast area. The reception intensity can be detected using, for example, C / N (carrier-to-noise ratio) and BER (Bit Error Rate).

  When the reception intensity determination unit 11 determines that the reception intensity is equal to or less than a predetermined value, the scan processing unit 12 has a predetermined reception intensity except for the channel having the same area code as the area code of the channel currently being received. Scan for available channels that exceed the value. The scan process is a process for generating a channel list by detecting a channel that can be received at the current position by changing the reception frequency of the tuner 2. The scan processing unit 12 acquires information on the physical channel and area code of the broadcast station that can be received at the current position from the data decoder unit 8 by executing this scan processing.

  In general scan processing, scanning of all frequencies (all channels) is executed. On the other hand, in the present embodiment, scanning is executed except for the channel having the same area code as that of the channel currently being received. The area code of the channel currently being received is obtained from the data decoder unit 8. For example, as shown in FIG. 4, when moving from the broadcasting area in Fukushima Prefecture to the broadcasting area in Ibaraki Prefecture, when the scanning processing is performed because the reception intensity of the channel currently being received is reduced, Except for channels assigned with area codes (hereinafter referred to as Fukushima codes), scan processing is executed only for other channels.

  The preset update unit 13 updates and stores the receivable channels extracted by the scan processing unit 12 in the preset memory 10. As described above, the information to be stored is information on the physical channel and area code of the broadcast station extracted as a receivable channel by the scan processing unit 12.

  Here, when more receivable channels than the number that can be registered in the preset memory 10 are extracted by the scan processing unit 12, the preset update unit 13 gives priority to, for example, a channel having a strong reception intensity in the preset memory 10. Try to remember. In this case, the plurality of receivable channels stored in the preset memory 10 may include a plurality of channels corresponding to a plurality of area codes.

  For example, as shown in FIG. 4, when moving from a broadcasting area in Fukushima toward a broadcasting area in Ibaraki, in addition to a channel assigned with an area code for Ibaraki (hereinafter referred to as Ibaraki code), There is a possibility that the scan processing unit 12 also extracts a channel to which an area code (hereinafter referred to as Tochigi code) is assigned. In this case, the preset updating unit 13 stores the Ibaraki code channel and the Tochigi code channel in the preset memory 10 in preference to those having strong reception strength.

  Alternatively, the preset update unit 13 may store only the channel of the area code having the largest number of extractions in the preset memory 10 among the receivable channels extracted by the scan processing unit 12. For example, it is assumed that the number of Ibaraki code channels extracted is the largest among the receivable channels extracted by the scan processing unit 12. In this case, even if the Tochigi code channel is extracted by the scan processing unit 12, the preset update unit 13 does not store the channel of the Tochigi code in the preset memory 10 but stores only the channel of the Ibaraki code in the preset memory 10.

  By the way, the reception intensity of the channel currently being received varies depending on the driving environment at that time. Therefore, even if the vehicle is not moving across different broadcast areas, the reception intensity may be equal to or less than a predetermined value for an indefinite time. Therefore, the reception strength determination unit 11 may determine whether or not the state in which the reception strength of the channel currently being received has become a predetermined value or less continues for a predetermined time or more. However, even if you do this, for example, when you are traveling in a densely populated area or mountainous area, even if the vehicle is not moving across different broadcast areas, you can receive the currently received channel. It is possible that the state in which the intensity is equal to or less than a predetermined value continues for a predetermined time or longer.

  Therefore, when the reception strength determination unit 11 determines that the reception strength of the currently received channel is equal to or lower than a predetermined value, the area code of the channel currently being received among the channels currently stored in the preset memory 10. It may be further determined whether or not the reception intensity of the channel of the same area code is equal to or less than a predetermined value. The area code of the channel currently being received is obtained from the data decoder unit 8. The scan processing unit 12 determines that the reception intensity is equal to or less than a predetermined value for a predetermined ratio or more of a channel currently being received and a channel having the same area code as the area code of the channel. In the case of reception, scan processing for receivable channels is performed.

  In this way, it can be detected more accurately that the vehicle is moving across different broadcast areas. That is, when moving from the broadcasting area in Fukushima Prefecture to the broadcasting area in Ibaraki Prefecture as shown in FIG. 4, not only the channel currently being received but also other channels to which the area code of Fukushima Prefecture is assigned have a predetermined reception intensity. There is a high possibility that it has fallen below the value. On the contrary, when traveling in the valleys or mountainous areas of buildings, the reception strength is reduced for some channels, but the reception strength is not reduced for a predetermined ratio or more of channels of the same area code. Therefore, by employing the above-described determination method, it is possible to more accurately detect that the vehicle is moving across different broadcast areas.

  FIG. 2 is a diagram illustrating an operation example of the digital broadcast receiving apparatus according to the present embodiment configured as described above. FIG. 2A shows an example of storage in the preset memory 11 before update. In the example of FIG. 2A, 10 receivable channels can be registered in the preset memory 10, and the Fukushima code channel and the Ibaraki code channel are stored in a mixed state. Of these, it is assumed that “18ch” of the Fukushima code is the channel currently being received.

  It is assumed that the vehicle is moving from the broadcast area in Fukushima Prefecture to the broadcast area in Ibaraki Prefecture, and the reception strength determination unit 11 determines that the reception strength of the channel currently being received is equal to or less than a predetermined value. In this case, as shown in FIG. 2B, the reception strength determination unit 11 continues to have a predetermined reception strength for a channel having the same Fukushima code as the currently received channel among the channels currently stored in the preset memory 10. It is determined whether or not it is less than or equal to the value.

  If the reception intensity determination unit 11 determines that the reception intensity is equal to or less than a predetermined value among the channels of the nine Fukushima codes stored in the preset memory 10, a scan process is performed. As shown in FIG. 2C, the unit 12 executes the scanning process except for the channel of the Fukushima code. Finally, as shown in FIG. 2 (d), the preset update unit 13 stores in the preset memory 10 only the channel of the Ibaraki code having the largest number of extractions among the receivable channels extracted by the scan processing unit 12. .

  FIG. 3 is a flowchart showing an operation example of the digital broadcast receiving apparatus according to the present embodiment configured as described above. Note that the flowchart shown in FIG. 3 starts when the power of the digital broadcast receiving apparatus is turned on.

  First, the reception strength determination unit 11 detects the reception strength of the channel currently being received (step S1), and determines whether or not the detected reception strength is a predetermined value or less (step S2). If the reception intensity is not less than the predetermined value, the process returns to step S1.

  On the other hand, when the reception intensity is less than or equal to the predetermined value, the reception intensity determination unit 11 continues to select one of the channels currently stored in the preset memory 10 and having the same area code as the channel currently being received. To do. Then, the reception intensity is detected for the selected channel (step S3), and it is determined whether or not the detected reception intensity is equal to or less than a predetermined value (step S4).

  Here, if the reception intensity of the selected channel is not less than the predetermined value, the process returns to step S1. On the other hand, when the reception strength of the selected channel is equal to or lower than the predetermined value, the reception strength determination unit 11 selects all channels having the same area code as the channel currently being received, and determines whether the reception strength determination is completed. Is determined (step S5). If the determination of the reception intensity has not been completed for all channels yet, the process returns to step S3.

  On the other hand, among the channels currently stored in the preset memory 10, when the reception strength determination is completed for all the channels having the same area code as the channel currently being received, that is, the reception strengths are all below a predetermined value. If it is determined that there is an area code, the scan processing unit 12 scans a receivable channel whose reception intensity exceeds a predetermined value except for the channel having the same area code as the area code of the currently received channel (step S6).

  Then, the preset update unit 13 updates and stores the receivable channels extracted by the scan processing unit 12 in the preset memory 10 (step S7). Thereafter, the digital broadcast receiving apparatus determines whether or not the power is turned off (step S8). If not turned off, the process returns to step S1. When the power is turned off, the process of the flowchart shown in FIG.

  As described above in detail, in the present embodiment, when the reception strength of the channel currently being received is equal to or less than a predetermined value, reception is performed except for the channel having the same area code as that of the channel currently being received. The possible channels are scanned, and the receivable channels extracted thereby are updated and stored in the preset memory 10.

  According to this embodiment configured as described above, the preset memory 10 is automatically updated because the reception intensity of the channel received in the source broadcast area is reduced while the vehicle is moving across different broadcast areas. At this time, the channel related to the source broadcast area (Fukushima code) is not preset, and only the channel related to the target broadcast area (Ibaraki code or Tochigi code) is preset. As a result, it is possible to prevent presetting of unnecessary channels (channels of the source broadcast area) that are likely not to be immediately received as the vehicle moves.

  Further, according to the present embodiment, since the scan process is executed except for the channel having the same area code as the area code of the channel currently being received, there is also an advantage that the scan time can be shortened.

  In the above-described embodiment, the scan processing unit 12 executes the scan process except for the channel having the same area code as the area code of the channel currently being received, and the preset update unit 13 sets the receivable channels extracted thereby. However, the present invention is not limited to this.

  For example, the scan processing unit 12 executes scan processing for all frequencies (all channels) in the same manner as general scan processing. Then, the preset update unit 13 selects only a channel having an area code different from the area code of the currently received channel from the receivable channels extracted by the scan processing unit 12 and stores the selected channel in the preset memory 10. Also good. However, the above embodiment is preferable in that it has a merit that the scan time can be shortened.

  Further, in the above embodiment, regarding a plurality of receivable channels to be stored in the preset memory 10, there are a case where channels corresponding to a plurality of area codes are mixed, and only a channel of an area code having the largest number of extractions by the scan processing unit 12. In the above description, two cases have been described, but either one may be automatically selected according to the situation. For example, it is possible to connect a navigation device to a digital broadcast receiving device and automatically select either one according to the setting status of the guide route.

  For example, the navigation area is notified of the broadcast area indicated by the area code having the second or less extraction number of receivable channels by the scan processing unit 12, and the guidance route set in the navigation apparatus exists in the broadcast area. Inquire whether or not. When there is no guidance route in the broadcast area indicated by the area code with the second or less extraction number, only the channel of the area code with the highest extraction number by the scan processing unit 12 is stored in the preset memory 10. On the other hand, when a guidance route exists in the broadcast area indicated by the area code with the second or less extracted number, the preset memory 10 is allowed to store a receivable channel while allowing a plurality of area codes to be mixed. In this way, useful channels relating to broadcast areas that are likely to move along the guidance path can be stored in the preset memory 10.

  Note that the preset update unit 13 determines whether or not the receivable channel extracted by the scan processing unit 12 regardless of whether the broadcast area where the guide route exists is a broadcast area indicated by an area code with the second or less extraction number. Among them, the channel of the broadcast area where the guide route exists may be selected and stored in the preset memory 10.

  In addition, each of the above-described embodiments is merely an example of implementation in carrying out the present invention, and the technical scope of the present invention should not be construed in a limited manner. That is, the present invention can be implemented in various forms without departing from the gist or the main features thereof.

DESCRIPTION OF SYMBOLS 10 Preset memory 11 Reception intensity determination part 12 Scan processing part 13 Preset update part

Claims (6)

A reception strength determination unit that determines whether or not the reception strength of the channel is equal to or lower than a predetermined value;
When the reception strength determining unit determines that the reception strength is equal to or lower than a predetermined value, the reception strength exceeds the predetermined value except for a channel having the same area code as the area code of the channel currently being received. A scan processor for scanning possible channels;
A digital broadcast receiving apparatus comprising: a preset updating unit that stores a receivable channel extracted by the scan processing unit in a preset memory.   2. The preset update unit according to claim 1, wherein among the receivable channels extracted by the scan processing unit, only the channel of the area code having the largest number of extractions is stored in the preset memory. Digital broadcast receiver. The reception strength determination unit determines whether or not the reception strength of the currently received channel is equal to or lower than a predetermined value, and determines that the channel currently stored in the preset memory is determined to be lower than the predetermined value. Among them, it is further determined whether or not the reception intensity of the channel of the area code that is the same as the area code of the currently received channel is below a predetermined value,
In the scan processing unit, the reception strength determination unit determines that the reception intensity is equal to or less than a predetermined value for a predetermined ratio of the channel currently being received and a channel having the same area code as the area code of the channel. 2. The digital broadcast receiving apparatus according to claim 1, wherein the receivable channel is scanned. A reception strength determination unit that determines whether or not the reception strength of the channel is equal to or lower than a predetermined value;
A scan processing unit that scans a receivable channel in which the reception intensity exceeds a predetermined value when the reception intensity determination unit determines that the reception intensity is equal to or less than a predetermined value;
A digital broadcast receiving apparatus, comprising: a preset update unit that stores, in a preset memory, a channel having an area code different from the area code of the currently received channel among the receivable channels extracted by the scan processing unit . A first step in which a reception intensity determination unit of the digital broadcast receiving apparatus determines whether or not the reception intensity of a channel currently being received is equal to or lower than a predetermined value;
When the scan processing unit of the digital broadcast receiving apparatus determines that the reception intensity is equal to or lower than a predetermined value by the reception intensity determination unit, a channel having the same area code as the area code of the currently received channel is selected. Except for a second step of scanning a receivable channel whose reception intensity exceeds a predetermined value;
A preset switching method, wherein the preset update unit of the digital broadcast receiving apparatus includes a third step of storing the receivable channels extracted by the scan processing unit in a preset memory. A first step in which a reception intensity determination unit of the digital broadcast receiving apparatus determines whether or not the reception intensity of a channel currently being received is equal to or lower than a predetermined value;
A scan processing unit of the digital broadcast receiving apparatus scans a receivable channel having the reception intensity exceeding a predetermined value when the reception intensity determination unit determines that the reception intensity is a predetermined value or less. Steps,
A third step in which the preset update unit of the digital broadcast receiving apparatus stores in the preset memory a channel having an area code different from the area code of the currently received channel among the receivable channels extracted by the scan processing unit. And a preset switching method.

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