WO2018179611A1 - Digital broadcast reception device, digital broadcast reception method, program and recording medium - Google Patents

Abstract

In a digital broadcast reception device mounted in a mobile object, channel scan history information of each physical channel is stored on a mesh-area-by-mesh-area basis, and a physical channel to be subjected to channel scanning is determined on the basis of the channel scan history information. The channel scan history information may be information indicating whether or not each of the physical channels has been selected. The channel scan history information may be information indicating a day or month when each of the physical channels was last selected, or may be information indicating a day or month when channel scanning was last completed in the corresponding mesh area. Consequently, the present invention requires less information to be stored, and enables efficient channel scanning and an improvement in the accuracy of automatic channel selection switching.

Description

Digital broadcast receiving apparatus, digital broadcast receiving method, program, and recording medium

The present invention relates to a mobile digital broadcast receiver, for example, a digital broadcast receiver mounted on a mobile body and moving. The present invention also relates to a digital broadcast receiving method in such a digital broadcast receiving apparatus. The present invention also relates to a program for causing a computer to execute processing in a digital broadcast receiving apparatus or method, and a recording medium on which the program is recorded.

When a mobile body equipped with a digital broadcast receiving device, for example, a vehicle, moves from within the receivable area of the physical channel received by the digital broadcast receiving device to outside the receivable area, the physical channel that has been normally received Will not be able to view the broadcast service provided by. In this case, the user manually detects the receivable physical channel by causing the digital broadcast receiving apparatus to perform channel scanning, and the user selects a physical channel that provides the same broadcast service from among them. The method is known.

Further, for example, Patent Documents 1, 2, and 3 disclose digital broadcast receiving apparatuses having a broadcast signal tuning function that do not require the above-described manual operation.
The digital broadcast receiving apparatus disclosed in Patent Document 1 has a first function of performing diversity reception by two receiving means and reception for program reproduction (program viewing) by one of the two receiving means. And a function switching means for switching between a second function for seeking information on channel selection by seeking a physical channel periodically (for example, at a time interval of 15 minutes) by the other receiving means. The acquired information is stored, and when a physical channel that can be received changes with movement, the physical channel is immediately switched to a receivable physical channel (for example, claim 2 of the patent document, abstract).

The digital broadcast receiving apparatus disclosed in Patent Document 2 includes area information including reception mode information indicating whether one-segment broadcasting or full-segment broadcasting can be received, for each mesh obtained by finely dividing a nationwide broadcasting area. A stored area information storage unit and a channel switching unit that switches a reception channel based on area information corresponding to the current position of the vehicle are provided, and the reception channel is automatically switched.

A digital broadcast receiving apparatus disclosed in Patent Document 3 includes a broadcast area map storage unit that stores broadcast area map generated area information together with a broadcast area map that represents a receivable position, and a broadcast area map stored in the broadcast area map storage unit. A broadcast area map non-generated area determination unit that determines whether or not the current position is within the broadcast area map non-generated area by referring to the generated area information, and based on the information of the broadcast area map non-generated area determination unit, Determine whether to perform a channel scan at a position.

Japanese Patent Laying-Open No. 2005-217681 (Claim 2) JP 2013-138287 A (Claim 1, paragraphs 0028 and 0033, FIG. 1 and FIG. 2) JP2013-225895A (paragraphs 0018 and 0024)

However, in the digital broadcast receiving apparatus described in Patent Document 1, since the physical channel seek (channel scan) is periodically performed at a constant time interval, the result of the channel scan is a maximum of the above constant time interval. However, there is a problem that the physical channel selected by using the result of the channel scan is not appropriate because the channel becomes old.

Although it is conceivable to increase the probability that the selected physical channel is appropriate by setting the above-mentioned fixed time interval short, in this case, a program based on a high-quality received signal is used. There has been a problem that the period for performing diversity reception enabling viewing is shortened.

Furthermore, even when a mobile object equipped with a digital broadcast receiver does not move, channel scans are regularly performed, and there are many useless channel scans that do not contribute to improving the accuracy of automatic channel selection switching. As a result, the operation becomes inefficient.

In the digital broadcast receiving apparatus described in Patent Document 2, since there is no means for updating the area information stored in the area information storage unit, the broadcast transmission output of the transmitting station is changed or the transmitting station is newly installed, There was a problem that it was not possible to cope with changes in the coverage area due to relocation and abolition.

Also, there is a problem that a large storage area is required to store area information including a set of broadcast station name, TSID, affiliated station ID, reception mode, and physical channel for each mesh.

In the digital broadcast receiving apparatus described in Patent Document 3, it is determined whether or not the current position is in the broadcast area map non-generated area based on information indicating the area map generated area. Since it is approximated by a polygon generated based on the determination result of whether or not reception is possible at a point scanned in the past, an unscanned point may be determined as scanned and excluded from the scan target. is there. As a result, the reception mode is switched based on inaccurate information, and there is a problem that the effect of increasing the high-quality viewing period due to the reduction of the scan time cannot be obtained.

The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to more appropriately determine a physical channel to be selected by channel scanning, and to perform automatic channel scanning. There is less information to be stored for control, and channel scanning can be performed efficiently.

A digital broadcast receiving apparatus according to the present invention,
A digital broadcast receiver having at least one tuner / demodulator for selecting a physical channel and demodulating a broadcast signal of the selected physical channel,
A current position detection unit for detecting a current position of the digital broadcast receiver;
A channel scan controller for performing a channel scan to determine whether each physical channel is receivable using the at least one tuner / demodulator;
Based on the result of the channel scan, a broadcast area map generator that generates information indicating an area that can be received for each physical channel;
A broadcast service list generating unit that generates a service list indicating a broadcast service that can be received at each point based on the generated information indicating the receivable area;
A channel scan history storage unit that stores channel scan history information indicating the history of the channel scan for each mesh area;
The channel scan control unit performs channel scan based on information about a mesh area to which a current position detected by the current position detection unit belongs among the channel scan history information stored in the channel scan history storage unit. The physical channel to be tuned in is determined.

According to the present invention, since channel scan history information is stored for each mesh area, it is possible to more appropriately determine a physical channel to be selected by channel scanning. Also, the amount of information that needs to be stored for automatic channel scan control can be reduced. Furthermore, the number of physical channels to be subjected to channel scanning can be reduced, or the frequency of channel scanning can be reduced, so that channel scanning can be performed efficiently.

It is a block diagram which shows roughly the structure of the digital broadcast receiver which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the information showing the broadcast area map hold | maintained at the broadcast area map storage part of the digital broadcast receiver which concerns on Embodiment 1 with a table format. It is a figure which shows an example of the receivable area about one physical channel contained in the broadcast area map of FIG. It is a figure which shows an example of the channel scan history information hold | maintained at the channel scan history storage part of FIG. 1 in a table format. It is a flowchart which shows the broadcast service list production | generation process by the broadcast service list production | generation part of FIG. It is a flowchart which shows the channel scan history determination process by the channel scan history determination part of FIG. It is a flowchart which shows the process of the channel scan by the channel scan control part of FIG. It is a figure which shows an example of the channel scan log | history information hold | maintained at the channel scan log | history storage part of the digital broadcast receiver which concerns on Embodiment 2 of this invention with a table format. 10 is a flowchart illustrating channel scan history determination processing by a channel scan history determination unit according to the second embodiment. It is a figure which shows an example of the channel scan log | history information hold | maintained at the channel scan log | history storage part of the digital broadcast receiver concerning Embodiment 3 of this invention with a table format. 10 is a flowchart illustrating channel scan history determination processing by a channel scan history determination unit according to the third embodiment. It is a figure which shows an example of the channel scan log | history information hold | maintained at the channel scan log | history storage part of the digital broadcast receiver concerning Embodiment 4 of this invention with a table format. It is a block diagram which shows schematically the structure of the digital broadcast receiver which concerns on Embodiment 5 of this invention. It is a block diagram which shows an example of the structure which implement | achieved a part of digital broadcast receiver of FIG. 1 with the computer. It is a block diagram which shows an example of the structure which implement | achieved a part of digital broadcast receiver of FIG. 13 with the computer.

Embodiment 1 FIG.
FIG. 1 is a block diagram schematically showing a configuration of a digital broadcast receiving apparatus 1 according to Embodiment 1 of the present invention. A digital broadcast receiving apparatus 1 shown in FIG. 1 includes a first broadcast receiving antenna 11, a first tuner / demodulator 12, a first demultiplexer 13, a video / audio decoder 14, The graphics superimposing unit 15, the video output unit 16, the audio output unit 17, the operation input unit 18, and the channel selection control unit 19 are provided. The digital broadcast receiving apparatus 1 further includes a second broadcast receiving antenna 21, a second tuner / demodulator 22, a second demultiplexer 23, a reception mode switching unit 24, and a channel scan controller 25. A current position detection antenna 26, a current position detection unit 27, a broadcast area map generation unit 28, a broadcast area map storage unit 29, a channel scan history determination unit 30, a channel scan history storage unit 39, and a broadcast service A list generation unit 31.
Note that the first tuner / demodulator 12, the second tuner / demodulator 22, and the reception mode switching unit 24 may be configured in one broadcast signal receiver 40.

The operation input unit 18 is used when a user performs operation inputs such as power on / off, a broadcast service list presentation request, and channel selection.

The current position detection unit 27 detects the current position of the digital broadcast receiver 1. In the example of FIG. 1, the current position detection unit 27 detects the current position of the digital broadcast receiving apparatus 1 based on a signal from an antenna (for example, a GPS antenna) 26 for detecting the current position, and information indicating the current position, for example, Information indicating longitude and latitude is output.

The first broadcast receiving antenna 11 and the first tuner / demodulator 12 constitute a first system of broadcast receiving means. The second broadcast receiving antenna 21 and the second tuner / demodulator 22 constitute a second system of broadcast receiving means. The first system broadcast receiving means and the second system broadcast receiving means can operate independently of each other.

The reception mode switching unit 24 switches the reception mode of the digital broadcast receiving device 1 between the double tuner mode and the single tuner mode in accordance with a switching control signal from the channel scan control unit 25.
In the single tuner mode (first operation mode), two systems of broadcast receiving means select the same physical channel, and receive signals from the two systems of broadcast receiving means are diversity-processed. One TS (transport stream) with high reception stability is output from the first tuner / demodulator 12 by diversity processing.
In the double tuner mode (second operation mode), each system of broadcast receiving means (each of the first tuner / demodulator 12 and the second tuner / demodulator 22) selects a physical channel independently of each other. .

In the single tuner mode, the second demultiplexing unit 23 is not used, and the output of the second tuner / demodulation unit 22 is input to the first tuner / demodulation unit 12 via the reception mode switching unit 24. The first tuner / demodulator 12 performs diversity with respect to the broadcast signal from the antenna 11 and the broadcast signal input from the antenna 21 via the second tuner / demodulator 22 and the reception mode switching unit 24. The process is performed to generate one TS.

The first demultiplexer 13 separates the TS generated by the first tuner / demodulator 12 into video data and audio data based on PID (packet identification information), and converts the video data and audio data into video / audio data. Output to the audio decoding unit 14. The first demultiplexer 13 also supplies section data to the channel scan controller 25. The first demultiplexing unit 13 also notifies the channel selection control unit 19 and the channel scan control unit 25 when section data is interrupted.

The video / audio decoding unit 14 decodes the video data and audio data output from the first demultiplexing unit 13 and outputs a video signal and an audio signal. The video / audio decoding unit 14 also supplies information indicating the decoding error rate to the channel scan control unit 25.

The audio output unit 17 outputs a sound based on the audio signal output from the video / audio decoding unit 14 from a speaker (not shown), or outputs an audio signal from an output terminal (not shown).
The graphics superimposing unit 15 superimposes the video represented by the video signal output from the video / audio decoding unit 14 and the graphics data. The superimposed graphics data represents, for example, a broadcast service list described later.
The video output unit 16 displays a video represented by the video signal output from the graphics superimposing unit 15 on a display unit (not shown), or outputs the video signal from an output terminal (not shown).

The channel scan control unit 25 switches the operation mode to the double tuner mode when performing the channel scan.
In the double tuner mode, the output of the first tuner / demodulation unit 12 is used for program viewing, and in this state, the channel scan control unit 25 switches the second tuner / demodulation unit 22 and the second demultiplexing unit 23. Channel scan.
That is, in the double tuner mode, the broadcast signal received by the first broadcast receiving antenna 11 is transmitted through the first tuner / demodulator 12, the first demultiplexer 13, and the video / audio decoder 14. Via, it is converted into a video signal and an audio signal and output. Then, the audio signal is supplied to the audio output unit 17. The video signal is supplied to the graphics superimposing unit 15, superimposed on the graphics data, and then supplied to the video output unit 16.

On the other hand, the broadcast signal received by the second broadcast receiving antenna 21 is sent to the channel scan control unit 25 and the broadcast area map generation unit 28 via the second tuner / demodulation unit 22 and the second demultiplexing unit 23. Supplied. In the channel scan, the second tuner / demodulator 22 sequentially selects physical channels (channels in which a specific frequency bandwidth is defined as one unit) and determines whether or not each physical channel can be received. .

Whether or not each physical channel can be received is determined based on whether or not a sufficiently large received signal can be obtained when tuning to the physical channel, that is, the power level of the received signal is greater than a predetermined value. It is performed based on the result of the determination whether or not the frame is locked, the result of the determination whether or not the frame is locked, and the result of the determination whether or not the PSI / SI information is acquired.

The channel scan using the second tuner / demodulator 22 is executed in a state in which the viewer does not notice while the first tuner / demodulator 12 is viewing the program (behind program viewing). This is also called “back channel scan”.

Channel selection in the channel scan is controlled by the channel scan control unit 25.
The channel scan is executed, for example, when an unselected physical channel list is transmitted from the channel scan history determination unit 30 as described later.

Information indicating whether or not each physical channel has been selected by channel scanning (channel selection history information) is recorded in the channel scan history storage unit 39.
A channel selected by channel scanning is said to have been selected. A channel that has never been selected by channel scanning is called “unselected”. Furthermore, channel selection history information indicating whether or not a channel has been selected by channel scanning may be referred to as a “selected channel flag”.
“Never selected by channel scanning” generally means that the channel has never been selected since the use of the digital broadcast receiving apparatus was started. However, if the stored contents of the broadcast area map storage unit 29 and the channel scan history storage unit 39 are erased due to resetting for some reason, for example, the channel has never been selected after such erasure. means.

The channel scan is performed at a plurality of points as the mobile object equipped with the digital broadcast receiving device moves.
The broadcast area map generation unit 28 generates a broadcast area map based on the results of channel scans performed at a plurality of points. Specifically, the broadcast area map generation unit 28 includes information indicating a point where channel selection is performed in the channel scan (current position indicated by position information from the current position detection unit 27), selection in the channel scan at each point. A broadcast area map is generated based on information indicating whether or not each physical channel is determined to be receivable by the station and broadcast service information regarding the broadcast contents of each physical channel acquired by reception.

The broadcast area map generation unit 28 stores the generated broadcast area map in the broadcast area map storage unit 29 as a database.

The broadcast area map stored in the broadcast area map storage unit 29 was viewed up to now, for example, when the reception status of the broadcast service provided on the physical channel currently being received deteriorated as the mobile object moved. Is used to automatically switch to another physical channel providing the same program.

FIG. 2 is a diagram showing the structure of the broadcast area map stored in the broadcast area map storage unit 29 in a tabular format. The broadcast area map includes information indicating a receivable area, information indicating a TS name or ensemble name, information indicating a broadcast service name, and a physical channel (CH) of a relay station for each of a plurality of physical channels (13ch, 14ch,...). And information indicating the physical channel (CH) of the affiliated station in association with each other. The receivable area is approximated by a polygon, and coordinates indicating the vertex of the polygon are recorded as information indicating the receivable area.
FIG. 3 is a diagram showing an example of a receivable area for one physical channel, specifically, 13ch in FIG. 2 stored in the broadcast area map storage unit 29.

The receivable area in FIG. 3 is approximated by a polygon. As the coordinates indicating the vertices of the polygon, the coordinates of the vertices are recorded in the order in which the vertices of the polygon are selected clockwise. For example, for 13 ch, as shown in FIG. 3, polygon vertices Point 10, Point 20,... Pointm indicated by reference numeral 50 are sequentially selected, and their coordinates (x ₁₀ , y ₁₀ ), (x ₁₁ , y _{11), (x 12, y} 12), ..., it is recorded in the selected order of the vertices corresponding the (x _{1m, y} 1m).
Vertex coordinates (x ₁₀ , y ₁₀ ), (x ₁₁ , y ₁₁ ),..., (X _1m , y _1m ) are orthogonal coordinate systems with the longitude axis as the X coordinate axis and the latitude axis as the Y coordinate axis. It is shown in

The TS name is recorded as a part of the broadcast area map as follows: ISDB-T (Integrated Services Digital Broadcasting-Terrestrial), DVB-T (Digital Video Broadcasting-Terrestrial), DVB-H-D This is the case of digital broadcasting standards such as (Digital Terrestrial Multimedia Broadcast) and ATSC (Advanced Television Systems Committee).
The ensemble name is recorded as a part of the broadcast area map in the case of digital broadcasting standards such as DAB (Digital Audio Broadcast), DAB + (Digital Audio Broadcast plus), DMB (Digital Multimedia Broadcasting) and the like.
In any case, one TS or one ensemble is transmitted by one physical channel, and a plurality of broadcast services exist in the transmission information. A user selects a broadcast service by performing an operation of selecting a physical channel, and views a program. In the example of FIG. 2, only one broadcast service name is described in each physical channel, but usually there are a plurality of broadcast service names.

As information indicating the relay station CH and information indicating the affiliated station CH, for example, information acquired from section data (for example, PSI / SI information) received by channel scanning is recorded.
By recording information indicating the relay station CH and information indicating the affiliated station CH as a part of the broadcast area map, the same program is broadcast by referring to the broadcast area map when the reception state of the broadcast signal deteriorates. Possible alternative physical channels can be grasped, and automatic switching in a short time can be realized.
In addition, there is a high possibility that physical channels with the same broadcast service name are broadcasting the same program. By recording the broadcast service name as part of the broadcast area map, when the reception status of the broadcast signal deteriorates, it is possible to grasp the alternative physical channel that is likely to be broadcasting the same program by referring to the broadcast area map And automatic switching can be realized in a short time.

The channel scan history storage unit 39 stores channel scan history information for each mesh area. The channel scan history information for each mesh area is information indicating the channel selection history of each physical channel in the channel scan performed in the mesh area. An example of channel scan history information is shown in FIG. The channel scan history information shown in FIG. 4 includes channel selection history information indicating whether or not each physical channel has been selected by channel scanning in each mesh area, that is, a channel selection completed flag.

The mesh area is an area formed by dividing the broadcast reception target area into a grid pattern by a line parallel to the meridian and a line parallel to the latitude, and the mesh area corresponds to its position (longitude and latitude). The number is given.
In the example shown in FIG. 4, the mesh area number is a sequential number from 0 to n.

The channel scan history determination unit 30 is selected from channel scan history information stored in the channel scan history storage unit 39 by channel scan in the mesh area to which the current position detected by the current position detection unit 27 belongs. A physical channel that does not occur is extracted, and the extracted list of physical channels is output as an unselected physical channel list.

When the unselected channel list is output from the channel scan history determination unit 30, the channel scan control unit 25 starts channel scanning in response to the output. In this case, the channel scan control unit 25 sequentially selects one or more physical channels included in the unselected channel list that is output from the channel scan history determination unit 30. When the channel scan control unit 25 selects one physical channel and determines whether or not reception is possible, it updates the channel scan history information held in the channel scan history storage unit 39 regardless of whether or not reception is possible. To do.
Specifically, every time one physical channel is selected, the channel scan control unit 25 sets the mesh area number (mesh area number) to which the current position belongs based on the position information from the current position detection unit 27. Identify.
Then, the information of the location corresponding to the identified number and corresponding to the selected physical channel is rewritten from “unselected” to “selected”.

For example, “unselected” is represented by “0” and “selected” is represented by “1”. In this case, the channel selection history information for one physical channel is expressed by 1 bit, and the number of bits equal to the number of physical channels is sufficient in one mesh area. For example, if the target of channel scanning is 40 physical channels in total from 13 channels to 52 channels, 40 bits, that is, 5 bytes are sufficient.

The broadcast service list generation unit 31 generates a broadcast service list based on the broadcast area map stored in the broadcast area map storage unit 29 and the current position detected by the current position detection unit 27. The broadcast service list is a list of information indicating broadcast services provided by a physical channel that can be received at the current position.
The broadcast service list is generated and presented, for example, when the user requests presentation of the broadcast service list using the operation input unit 18.

FIG. 5 is a flowchart showing broadcast service list generation and presentation processing by the broadcast service list generation unit 31 of the digital broadcast receiving apparatus according to the first embodiment.
As shown in FIG. 5, when the broadcast service list generation unit 31 starts the broadcast service list generation process (step S11), the broadcast service list generation unit 31 first performs the process of step S12.
In step S12, information indicating a physical channel that can be received at the current position is acquired from the current position information from the current position detection unit 27 and the broadcast area map stored in the broadcast area map storage unit 29.

In the next step S13, broadcast service information related to the broadcast content of the physical channel is acquired from information indicating a physical channel that can be received at the current position, and the information is acquired as information indicating a broadcast service that can be received at the current position. The broadcast service list is generated from the acquired information, and the generated broadcast service list is supplied to the graphics superimposing unit 15.
This completes the process of creating and presenting the broadcast service list.

The graphics superimposing unit 15 superimposes the graphics data representing the broadcast service list supplied from the broadcast service list generating unit 31 on the video signal supplied from the video / audio decoding unit 14 and outputs the video data to the video output unit 16. Then, the broadcast service list is displayed on the display unit connected to the video output unit 16. The user refers to the broadcast service list displayed and selects (selects) a broadcast service to be viewed on the operation input unit 18.

When a broadcast service channel selection request by the user is input from the operation input unit 18 to the channel selection control unit 19, the channel selection control unit 19 refers to the broadcast area map stored in the broadcast area map storage unit 29 and selects a channel. The physical channel to be determined is determined and a channel selection instruction is issued.
The channel selection instruction is sent to the first tuner / demodulator 12 in the double tuner mode, and is sent to the first tuner / demodulator 12 and the second tuner / demodulator 22 in the single tuner mode. In the single tuner mode, the output of the second tuner / demodulation unit 22 is sent to the first tuner / demodulation unit 12 via the reception mode switching unit 24. In any mode, the video output unit 16 and the audio output unit 17 are based on signals output via the first tuner / demodulator 12, the first demultiplexer 13 and the video / audio decoder 14. Outputs video and audio.

As described above, the broadcast area map stored in the broadcast area map storage unit 29 is the same as that which has been viewed up to now when the reception state of the physical channel currently being received deteriorates as the mobile object moves. It is used for automatic switching to other physical channels providing programs.

For this automatic switching, information indicating the reception state is supplied from the first tuner / demodulator 12, the first demultiplexer 13, and the video / audio decoder 14 to the channel selection controller 19.
Information indicating the reception state from the first tuner / demodulator 12 includes C / N (Carrier to Noise Ratio), bit error rate, tuner PLL (Phase Locked Loop) lock information, OFDM (Orthogonal Frequency Division Multiplexing). Frame lock information and the like are supplied.
As information indicating the reception state from the first demultiplexing unit 13, information indicating the interruption of section data (for example, PSI (Program Specific Information) / SI (Service Information) information) is supplied.
As information indicating the reception state from the video / audio decoding unit 14, information indicating a decoding error rate is supplied.

The channel selection control unit 19 displays information indicating the reception state from the first tuner / demodulation unit 12, information indicating the reception state from the first demultiplexing unit 13, and the reception state from the video / audio decoding unit 14. Based on the indicated information, it is determined whether or not the reception state of the broadcast signal has deteriorated. If it is determined that the reception status of the broadcast signal has deteriorated, the channel selection control unit 19 is able to receive the same program at the current position, broadcasts the same program, or is likely to be broadcasting the same program. Instructs automatic switching to.

Specifically, referring to the broadcast area map stored in the broadcast area map storage unit 29, if a different physical channel used for broadcasting of the same broadcast service is found, switching to the physical channel is instructed. . If the physical channel of the relay station or affiliated station of the broadcasting station that has been received is found, the switching to the physical channel of the relay station or affiliated station is instructed.

The instruction to switch the physical channel is given to the first tuner / demodulator 12 and the second tuner / demodulator 22 in the single tuner mode, and to the first tuner / demodulator 12 in the double tuner mode.

Hereinafter, the channel scan history determination process by the channel scan history determination unit 30 will be described in more detail.
FIG. 6 is a flowchart illustrating a procedure of channel scan history determination processing by the channel scan history determination unit 30.
The processing in FIG. 6 is desirably executed periodically, for example. It is desirable that the execution cycle be changed according to the moving speed of the moving body on which the digital broadcast receiving apparatus is mounted. For example, it is desirable to lengthen the execution cycle when the moving speed is low, and shorten the execution cycle when the moving speed is high. As an example, when the moving speed is an average speed, it may be executed once in several days.

When the channel scan history determination process is started (step S21), the process of step S22 is first performed.
In step S22, the channel scan history determination unit 30 receives information indicating the current position from the current position detection unit 27, and identifies the mesh area number from the information indicating the current position.
In the next step S23, the channel scan history determination unit 30 refers to the channel scan history information stored in the channel scan history storage unit 39, and records the mesh area number specified in step S22 (the channel scan history information). Among these, a portion corresponding to the mesh area number) is acquired.

In the next step S24, the channel scan history determination unit 30 refers to the record acquired in step S23 to determine whether or not one or more unselected physical channels exist in the mesh area. It is determined whether or not there is one or more physical channels whose completed flag is a value indicating “unselected”.

If it is determined in step S24 that one or more unselected physical channels exist, the process proceeds to step S25. Otherwise, the process ends.
In step S25, the channel scan history determination unit 30 extracts one or more unselected physical channel numbers, lists the extracted unselected physical channel numbers as a list, and performs channel scan as an unselected physical channel list. It supplies to the control part 25.
This completes the channel scan history determination.

The channel scan control unit 25 starts the channel scan when it receives the unselected physical channel list. For this purpose, first, the reception mode switching unit 24 is instructed to switch to the double tuner mode. In the double tuner mode, the first tuner / demodulator 12 performs a viewing operation, and in parallel with this, channel scanning using the second tuner / demodulator 22 is performed.

Hereinafter, the channel scan processing performed by the channel scan control unit 25 in response to the supply of the unselected physical channel list from the channel scan history determination unit 30 will be described with reference to FIG.
When the channel scan is started, in step S32, the channel scan control unit 25 instructs the reception mode switching unit 24 to switch to the double tuner mode.

In the next step S33, the channel scan control unit 25 determines a physical channel to be selected. This determination is performed by selecting one of the physical channels (unselected physical channels extracted by the channel scan history determination unit 30) included in the list of unselected physical channels sent from the channel scan history determination unit 30. It is done by selecting.

In the next step S34, the channel scan control unit 25 gives the second tuner / demodulation unit 22 an instruction to execute tuning for the physical channel selected in step S33. In response to this, the second tuner / demodulator 22 tunes to the physical channel selected in step S33.

Following step S34, a determination process is performed to determine whether or not the selected physical channel can be received at the current position. This determination process includes steps S35 to S38.
First, in step S35, the channel scan control unit 25 determines whether a broadcast signal exists in the tuned physical channel. This determination is made based on, for example, whether or not the power level of the received signal is greater than a predetermined value.
When it is determined that there is a broadcast signal, the process proceeds to step S36. Otherwise, the process proceeds to step S40.

In step S36, the channel scan control unit 25 performs frame lock determination. In this frame lock determination, for example, in the case of ISDB-T, a CRC (Cyclic Redundancy Check) error check in a TMCC (Transmission and Multiplexing Configuration and Control) signal or a periodic synchronization word check is performed. A determination is made as to whether the desired digital broadcast wave is to be received.
If the frame is locked (YES in S36), the process proceeds to step S37. Otherwise, the process proceeds to step S40.

In step S37, the channel scan control unit 25 starts PSI / SI section filtering processing and attempts to acquire PSI / SI information.
In the next step S38, the channel scan control unit 25 determines whether or not PSI / SI information has been acquired within a predetermined time. If PSI / SI information can be acquired within a predetermined time, the process proceeds to step S39. Otherwise, the process proceeds to step S40.

As described above, if the determination results in steps S35, S36, and S38 are all YES, it means that reception is possible, and the process proceeds to step S39, and any of the determination results in steps S35, S36, and S38. If it is NO, it means that it was not received, and the process proceeds to step S40.

In step S39, the channel scan control unit 25 extracts broadcast service information from the acquired PSI / SI information, information indicating the physical channel, and information indicating the power level of the received signal, together with information indicating the current position, a broadcast area map. The generation unit 28 is notified.
The broadcast area map generation unit 28 generates or corrects a broadcast area map based on the information received from the channel scan control unit 25, and updates the broadcast area map stored in the broadcast area map storage unit 29 with the generated or corrected broadcast area map. .

In step S40, the channel scan control unit 25 notifies the broadcast area map generation unit 28 of information indicating that the physical channel selected in step S33 could not be received at the current position, together with information indicating the current position.
The broadcast area map generation unit 28 generates or corrects a broadcast area map based on the information received from the channel scan control unit 25, and updates the broadcast area map stored in the broadcast area map storage unit 29 with the generated or corrected broadcast area map. .
After step S39 or step S40, the process proceeds to step S41.

In step S41, the channel scan control unit 25 updates the channel scan history information stored in the channel scan history storage unit 39. That is, the current position information from the current position detection unit 27 is received, the mesh area number is obtained from the current position information, and the selected flag of the corresponding physical channel column in the row of the corresponding mesh area number is set to “selected channel”. Update to

In the next step S42, the channel scan control unit 25 determines whether or not channel selection has been performed for all unselected physical channels. All the unselected physical channels mentioned here mean all of the unselected physical channels included in the unselected physical channel list transmitted from the channel scan history determination unit 30.
If channel selection has been performed for all unselected physical channels (YES in S42), the process proceeds to step S43.

If any unselected physical channel included in the unselected physical channel list has not yet been selected (NO in S42), the process returns to step S33. In step S33, the channel scan control unit 25 determines a physical channel to be selected next. That is, one of the unselected physical channels included in the unselected physical channel list sent from the channel scan history determination unit 30 is selected.
As a result of the above, until the selection of all unselected physical channels is completed, the determination of the physical channel (step S33), the tuning by the second tuner / demodulator 22 and the broadcast signal by the channel scan controller 25 are performed. The presence / absence determination is repeated.

In step S43, the channel scan control unit 25 notifies the reception mode switching unit 24 to operate in the single tuner mode, and ends the channel scan.

The case where the channel scan instruction is given by the notification of the unselected physical channel list from the channel scan history determination unit 30 has been described above.
The channel scan may be executed even when network configuration information, broadcast service configuration information, or the like changes. For this purpose, the channel scan control unit 25 obtains section data (for example, PSI / SI information) from the first demultiplexing unit 13 while viewing the program, and network configuration information and broadcast service configuration information from the section data. Etc. and detect these changes.

Changes in network configuration, broadcast service configuration, etc. include broadcast service loss, transmission physical channel change, network identification value change, broadcast service identification value change, network name change, TS name change, ensemble name change , And broadcast service name changes. In these cases, the broadcast service configuration may have changed for other physical channels. When there is such a change or change, it is necessary to detect the change or change and update the broadcast area map. Therefore, as described above, channel scanning is performed in accordance with changes in the network configuration, broadcast service configuration, etc., and the broadcast area map is updated.

The channel scan when a change in the above network configuration, broadcast service configuration, etc. is detected can be performed in the same procedure as shown in FIG. However, the channel scan target is not limited to the unselected physical channel, but differs in that all physical channels are used. That is, in step S33, one physical channel is selected from all physical channels one by one.

As described above, according to the digital broadcast receiving apparatus according to Embodiment 1, whether or not each physical channel has been selected in the channel scan within each mesh area as the channel scan history information. Information (channel selection completed flag) is stored, and while moving in a mesh area, physical channels that have not been selected by channel scanning in the mesh area (physical channels not selected) are stored. Since the channel scan is performed only when it exists, it is possible to reduce the execution of the unnecessary channel scan (that is, it does not contribute to the improvement of the accuracy of automatic channel selection). As a result, the channel scan operation becomes efficient. Further, it is possible to increase the period for performing the diversity processing. Therefore, it is possible to increase the period during which a program is viewed by generating a highly stable received signal by diversity processing.

Also, since only physical channels (unselected physical channels) that have not been selected by channel scanning in the past at the current position are subject to channel scanning, it is possible to further reduce the execution of useless channel scanning.

Further, whether or not each physical channel has been selected in the channel scan in each mesh area (whether or not the channel has been selected) can be expressed by 1 bit, so that channel scan history information is stored. Requires less storage space.

Furthermore, since a broadcast area map including broadcast service information is automatically generated by channel scanning, a list of broadcast services that can be received at that point can be presented to the user when the area where the broadcast area map is created is moved. Convenience when mounted on a mobile object can be improved.

Further, when the broadcast area map includes information indicating the physical channel of the relay station or affiliated station and information indicating the name of the broadcast service, when the area in which the broadcast area map is created is moved, reception of the broadcast service being viewed is received. If you are moving out of a possible area, or if the reception status becomes unstable, etc., the relay station, affiliated station, or the same broadcasting service name that is likely to be broadcasting the same program It is possible to automatically switch to a physical channel that broadcasts a broadcast service, and to avoid interruption of program viewing.

Further, when the information indicating the receivable area included in the broadcast area map is information indicating the coordinates of the vertexes of a polygon that approximates the receivable area, it indicates whether or not each mesh area is located within the receivable area. Compared to storing information, the amount of information can be reduced, and a storage area for recording information indicating a receivable area can be reduced.

Furthermore, the broadcast area map includes information indicating the broadcast service for each physical channel and information indicating the receivable area, and the broadcast area map is updated each time the channel is scanned. Can respond to changes in coverage area due to new establishment, relocation, abolition, etc.

Further, in the digital broadcast receiving apparatus according to the first embodiment, even when moving within the area where the channel scan is performed, a change in the network configuration, the broadcast service configuration, etc. is detected from the physical channel being viewed. When the channel scan is executed, the broadcast area map can be updated even when the network configuration, the broadcast service configuration, etc. change, and the broadcast area map can be kept up-to-date.

Embodiment 2. FIG.
In the first embodiment, the channel selection history flag is stored for each physical channel for each mesh area as channel scan history information. In this case, once “tuned” is set, the state set to “tuned” is maintained thereafter, and channel scanning is not performed. On the other hand, after a long period of time, the reception situation may change due to, for example, a high building that makes it difficult to receive broadcast waves, changes in the broadcast transmission output of the transmitting station, new establishment, relocation, or abolition of the transmitting station. possible. In such a case, if a new channel scan is not performed, there arises a problem that a change in the situation is not reflected in the broadcast area map. This problem can be solved by performing a regular channel scan.

However, the periodic channel scan has a problem that it takes time because all physical channels are subject to channel scan. Therefore, in the second embodiment, for each mesh area, the date when the channel scan was last executed for each physical channel is recorded, and when a preset period (set period) has elapsed from the recorded execution date, The channel scan is performed again on the physical channel. The above set period is preferably set to about several months, for example.
Whether or not the set period has elapsed can be determined by the periodic channel scan history determination process described in the first embodiment.

The configuration of the digital broadcast receiving apparatus according to Embodiment 2 is the same as that of the digital broadcast receiving apparatus of Embodiment 1 shown in FIG.

FIG. 8 is a table showing an example of channel scan history information held in the channel scan history storage unit 39 of the digital broadcast receiving apparatus according to the second embodiment. The channel scan history information in FIG. 8 is information about each mesh area, as in the first embodiment, and includes channel selection history information about each of a plurality of physical channels. If the corresponding physical channel has never been selected by channel scanning in the corresponding mesh area (when it is “unselected”), the channel selection history information indicates that (“unselected channel”). When the corresponding physical channel has been selected at least once by the channel scan in the corresponding mesh area, the channel selection execution date is indicated.
The channel selection execution date mentioned here is the date when the corresponding physical channel was last selected by the channel scan in the corresponding mesh area.

The channel selection history information is set to a value indicating “unselected”, for example, “−1” as an initial value.
When the channel selection history information indicates the channel selection execution date, the total date starting from a certain reference date is represented by 2 bytes. By assigning 2 bytes (16 bits), it is possible to represent which day of about 180 years. This period is sufficient for the operation of the digital broadcast receiving apparatus.

Channel selection history information for each mesh area
(Number of physical channels) x 2
The number of bytes is equal to. For example, if the number of physical channels subject to channel scanning is 40,
40 × 2 = 80 bytes. That is, in order to store channel scan history information, a storage area of 80 bytes per mesh is required.

The channel scan history determination unit 30 periodically performs a channel scan history determination process as in the first embodiment.
FIG. 9 is a flowchart illustrating a procedure of channel scan history determination processing by the channel scan history determination unit 30 according to the second embodiment. In FIG. 9, steps S21, S22, S23, and S25 are the same as those in FIG.

In step S51 following step S23, the channel selection history information for each physical channel is referred to, the channel selection history information represents the channel selection execution date, and the elapsed period from the channel selection execution date is equal to or longer than the set period. It is determined whether there is a physical channel.
If there is a physical channel whose elapsed time from the channel selection execution date is equal to or longer than the set period in step S51 (if YES), the process proceeds to step S52, and if not, the process proceeds to step S53.

In step S52, the channel selection history information for the physical channel for which it has been determined in step S51 that the elapsed period from the channel selection execution date is equal to or longer than the set period is rewritten to a value indicating “unselected channel”. When there is a physical channel for which the elapsed period from the channel selection execution date is determined to be equal to or longer than the set period, the channel selection history information for all physical channels is rewritten to a value indicating “unselected”. May be.

After step S52, the process proceeds to step S53.
In step S53, the channel scan history determination unit 30 determines whether or not there is one or more physical channels whose channel selection history information is a value indicating “unselected”. The physical channel whose channel selection history information has a value indicating “unselected” includes the physical channel in which the channel selection history information is rewritten to “unselected” in step S52.
If it is determined in step S53 that there is one or more physical channels whose channel selection history information is “unselected”, the process proceeds to step S25. Otherwise, the process ends.

In step S25, as in the first embodiment, the channel scan history determination unit 30 displays a list of physical channels whose channel selection history information has a value indicating “unselected” as an unselected physical channel list. Is supplied to the channel scan control unit 25.

As described above, in the second embodiment, the channel scan history determination unit 30 is selected by channel scanning in the mesh area to which the current position belongs by referring to the channel scan history information for the mesh area to which the current position belongs. (The value indicating “unselected” is recorded as the channel selection history information), or the elapsed time since the last channel selection in the channel scan within the mesh area is preset A list including physical channels that are equal to or longer than the period (the elapsed period from the channel selection execution date is equal to or longer than the set period) is output as an unselected physical channel list.

When the unselected channel list is output from the channel scan history determination unit 30, the channel scan control unit 25 starts channel scanning in response to the output.
The channel scan is performed in the same procedure as described with reference to FIG. However, not only the case where the physical channel list that has not been selected in the channel scan has been included in the unselected physical channel list, but only the physical channels whose elapsed time from the channel selection execution date is longer than the set period. In some cases, a physical channel that has never been selected in the channel scan and a physical channel whose elapsed time from the selection execution date is longer than the set period may be included. It is different.

Generally, the channel scan is first performed in each mesh area after the use of the digital broadcast receiving apparatus is started or the stored contents of the broadcast area map storage unit 29 and the channel scan history storage unit 39 are erased. In this case, the physical channels included in the unselected physical channel list are composed only of physical channels in which a value indicating “unselected” is recorded as channel selection history information (at the start of the process of FIG. 9).
On the other hand, after a channel scan is completed, many of the physical channels included in the unselected physical channel list (at the start of the process of FIG. 9) have an elapsed period from the channel selection execution date that is greater than or equal to the set period. Consists only of the physical channel that had been. However, since there is a physical channel that was not selected for some reason in the first channel scan, the channel that was recorded with the value indicating “unselected” as the channel selection history information, and channel selection There is a possibility that a physical channel whose elapsed period from the day is equal to or longer than the set period is included in the same unselected physical channel list.

When each physical channel is selected by the channel scan, the channel scan control unit 25 stores the channel selection date as the channel selection execution date and stores the channel selection execution date in the channel scan history storage unit 39. Update the existing channel scan history information. That is, the information indicating the new channel selection execution date is overwritten on the channel selection history information stored so far. The process of overwriting the new channel selection execution date is performed instead of the process of step S41 in FIG. 7 (process of updating the channel selection flag to “channel selection completed”).

The channel scan performed periodically according to the channel scan history determination process has been described above. In the first embodiment, the channel scan performed according to the change in the network configuration, the broadcast service configuration, and the like has been described. In the second embodiment, the channel scan is performed according to the change in the network configuration, the broadcast service configuration, and the like. It can be carried out. In this case, channel scanning is performed not only on physical channels whose elapsed time from the channel selection execution date is longer than the set period, but also on all physical channels.
Even when channel scanning is performed according to changes in the network configuration, the broadcast service configuration, etc., when each physical channel is selected, the channel selection history information of the physical channel is rewritten. This rewriting is also performed by the channel scan control unit 25.

As described above, according to the digital broadcast receiving apparatus according to the second embodiment, even after all physical channels are selected at least once by channel scanning in the mesh area to which the current position belongs, In the channel scan history determination process to be performed, if a physical channel is found whose elapsed time since the channel was last selected in the channel scan in the mesh area to which the current position belongs is longer than the set period, such a physical channel is determined. A channel scan is performed as an object. Therefore, when the reception status changes, the change in the status can be reflected in the broadcast area map.
In addition, the time required for channel scanning can be shortened as compared with the case where channel scanning is periodically performed for all physical channels. As a result, the channel scan operation becomes efficient. Further, it is possible to increase the period for performing the diversity processing.

Embodiment 3 FIG.
The channel scan history information described in the second embodiment stores channel selection history information of the number of bits that can represent the channel selection execution date for each physical channel for each mesh area, and requires a large storage area. There is a problem of doing.

Embodiment 3 is intended to solve this problem. The configuration of the digital broadcast receiving apparatus according to Embodiment 3 is the same as that of the digital broadcast receiving apparatus of Embodiment 1 shown in FIG.

FIG. 10 is a table showing an example of channel scan history information held in the channel scan history storage unit 39 of the digital broadcast receiving apparatus according to the third embodiment. The channel scan history information in FIG. 10 is information on each mesh area, as in the first and second embodiments, and the scan completion history information on the mesh area and the channel selection history on each of a plurality of physical channels. Contains information.

The scan completion history information for each mesh area indicates that (when it is “incomplete”) that the channel scan in the mesh area has never been completed (that it is “incomplete”). When the channel scan in the mesh area has been completed once or more, the scan completion date is indicated.
The scan completion date referred to here is the date when the channel scan was completed last in the mesh area.
In the scan completion history information, a value indicating “incomplete”, for example, “−1” is set as an initial value.
When the scan completion history information indicates the scan completion date, the total date starting from a certain reference date is represented by 2 bytes.

The channel selection history information for each physical channel is also called a channel selection completed flag, and indicates whether or not the physical channel has been selected by channel scanning.
More specifically, if the channel scan in the corresponding mesh area has never been completed, the channel selection flag for each physical channel indicates the corresponding physical channel in the channel scan in the corresponding mesh area. Indicates whether or not the channel has been selected, and when the channel scan in the corresponding mesh area has been completed at least once, the corresponding physical channel is Indicates whether or not the channel has been selected.

In the initial state, the channel selection flag for each physical channel is set to a value indicating “unselected”, for example, “0”. In this state, when each physical channel is selected by channel scanning, the channel selection flag for the physical channel is updated to a value indicating “channel selection completed”, for example, “1”.
When the selected channel flag becomes “selected channel” for all physical channels, the date including that point is recorded as the “scan completion date”.
The channel scan history information is updated by the channel scan control unit 25.

The channel scan history determination unit 30 periodically performs a channel scan history determination process as in the first embodiment.
FIG. 11 is a flowchart illustrating a procedure of channel scan history determination processing by the channel scan history determination unit 30 according to the third embodiment. In FIG. 11, steps S21, S22, S23, and S25 are the same as those in FIG.

In step S61, the scan completion history information for the mesh area to which the current position belongs is referred to, and it is determined whether or not a value indicating “incomplete” is recorded as the scan completion history information.
When a value indicating “incomplete” is recorded as the scan completion history information in step S61 (when YES), the process proceeds to step S25, otherwise, the scan completion history information indicates the scan completion date. If YES, the process proceeds to step S62.

In step S62, it is determined whether or not the elapsed period from the scan completion date represented by the scan completion history information is equal to or longer than a preset period (set period).
If the elapsed period from the scan completion date is equal to or longer than the set period in step S62 (if YES), the process proceeds to step S63, and if not, the process ends.

In step S63, the channel selection completed flag for all physical channels is rewritten to a value indicating “unselected”. That is, in the channel scan history information for the mesh area, all the channel selection flags for each physical channel are rewritten to a value indicating “unselected”.

After step S63, the process proceeds to step S25.
In step S25, as in the first embodiment, the channel scan history determination unit 30 sets a list of physical channels whose channel selection flag is “unselected” as an unselected physical channel list. , And supplied to the channel scan control unit 25.
When the process proceeds to step S25 via step S63, all physical channels are included in the unselected physical channel list. When the process proceeds to step S25 without passing through step S63, the channel has been selected once by the channel scan in the mesh area, that is, the “unselected channel” before the start of the process of FIG. Only physical channels with no channel are included in the unselected physical channel list.

As described above, in the third embodiment, the channel scan history determination unit 30 refers to the channel scan history information for the mesh area to which the current position belongs, and the scan completion history information included in the channel scan history information indicates the current position. When the channel scan in the mesh area to which the channel belongs has never been completed, a list of physical channels that have not been selected yet is output as an unselected physical channel list, and the above scan completion history When the information indicates the scan completion date and the elapsed period from the scan completion date is equal to or longer than the set period, a list of all physical channels is output as an unselected physical channel list (S61 to S63, S25). .

When the unselected channel list is output from the channel scan history determination unit 30, the channel scan control unit 25 starts channel scanning in response to the output.
The channel scan is performed generally in the same procedure as described with reference to FIG.
When each physical channel is selected by the channel scan, the channel scan control unit 25 rewrites the channel selection flag for the physical channel to “channel selection completed”. This process is performed in step S41 of FIG.

By repeating steps S33 to S41, when the sequential channel selection of all physical channels is completed, it is considered that “the channel scan is completed”, and the date including the end point is set as the scan completion date. The scan completion history information stored in the channel scan history storage unit 39 is updated with the indicated information. That is, the information indicating the new scan completion date is overwritten on the scan completion history information stored so far.
This overwriting process can be performed in an additional step (not shown) inserted between step 41 and step S43 in FIG.

The channel scan performed periodically according to the channel scan history determination process has been described above. In the first embodiment, the channel scan performed according to the change in the network configuration, the broadcast service configuration, etc. has been described, but in the third embodiment, the channel scan is performed according to the change in the network configuration, the broadcast service configuration, etc. It can be carried out. In this case, even if the elapsed period from the scan completion date for each mesh area is not equal to or longer than the set period, channel scanning is performed for all physical channels.
Even when a channel scan is performed according to changes in the network configuration, the broadcast service configuration, etc., when the channel scan is completed, the scan completion date for the mesh area is rewritten. This rewriting is also performed by the channel scan control unit 25.

As described above, according to the digital broadcast receiving apparatus according to the third embodiment, even after all physical channels are selected at least once by channel scanning in the mesh area to which the current position belongs, In the channel scan history determination process to be performed, if it is detected that the elapsed time since the last channel scan was completed within the mesh area to which the current position belongs, it is targeted for all physical channels. Channel scan. Therefore, when the reception status changes, the change in the status can be reflected in the broadcast area map.

In the second embodiment, since the channel selection execution date is stored for each physical channel, all physical channels are newly subjected to channel scanning after the set period has elapsed. 3 stores the date on which the channel scan is completed for each mesh area, and a new channel scan is not executed unless a set period elapses after the channel scan in the mesh area is completed. For this reason, the length of the period from when a channel is selected in a certain channel scan until it is selected in the next channel scan differs depending on the physical channel.
However, since a change in reception status does not occur frequently, it is considered that there is little influence due to a difference in the period from channel selection in one channel scan until channel selection in the next channel scan.

Further, according to the digital broadcast receiving apparatus according to the third embodiment, when the elapsed time from the last channel scan in the mesh area to which the current position belongs becomes equal to or longer than the set period, all physical channels are scanned Therefore, it is possible to simultaneously update the broadcast area map reflecting the change in reception status for all physical channels.

Furthermore, according to the digital broadcast receiving apparatus according to the third embodiment, as the information indicating the scan completion date in the channel scan history information, as with the channel selection execution date in the second embodiment, a certain reference date Uses information that represents the total date starting from 2 bytes. As a result, 2 bytes are used to represent the scan completion date for each mesh area. Since the selected flag is represented by 1 bit, a number of bits equal to the number of physical channels is used for each mesh area. For example, if the number of physical channels subject to channel scanning is 40, 40 bits, that is, 5 bytes are required. Together with this and 2 bytes of information representing the scan completion date, a total of 7 bytes are required. That is, in order to store channel scan history information, a storage area of 7 bytes per mesh is required.
This is less than 1/11 of the storage area (80 bytes per mesh) required by the channel scan history information of the second embodiment. Since the storage area is small, the cost of the apparatus can be reduced.

Embodiment 4 FIG.
In the third embodiment, the time when scanning for each mesh area is completed is expressed in units of days. In the fourth embodiment, the time of completion of scanning for each mesh area is expressed in units of months. Thereby, the amount of channel scan history information, and hence the storage area for storing the information can be reduced.
The digital broadcast receiving apparatus according to the fourth embodiment is generally the same as the digital broadcast receiving apparatus according to the third embodiment, but differs in the following points.

FIG. 12 is a table showing an example of channel scan history information held in the channel scan history storage unit 39 of the digital broadcast receiving apparatus according to the fourth embodiment.
The channel scan history information of FIG. 12 is generally the same as the channel scan history information of FIG. 10, but differs in that it includes a scan completion month instead of a scan completion date for each mesh area.

The scan completion month uses information that represents the total month with 1 month as the reference (starting point) in 1 byte. By assigning 1 byte (8 bits), it is possible to express which month in about 20 years.

As described in the third embodiment, since the channel selection flag is represented by 1 bit, a number of bits equal to the number of physical channels is used for each mesh area. For example, if the number of physical channels subject to channel scanning is 40, 40 bits, that is, 5 bytes are required. A total of 6 bytes are required, including this and 1 byte of information indicating the scan completion month. That is, a storage area of 6 bytes per mesh is required for storing channel scan history information.

This is about 85% of the storage area required by the channel scan history information of the third embodiment, and the storage area is smaller than that of the third embodiment, so that the cost of the apparatus can be reduced.

As described above, the fourth embodiment is described as a modification of the third embodiment. Similar modifications can be made to the second embodiment. That is, in the second embodiment, the channel selection execution month may be recorded instead of the channel selection execution date of each physical channel.

In the first, second, third, and fourth embodiments, the number of systems of the broadcast receiving means is 2, but the number of systems may be 3 or more. In short, a plurality of broadcast receiving means are provided, and in the first operation mode, the plurality of broadcast receiving means are all used for viewing the program, and in the second operation mode, of the plurality of broadcast receiving means. Any broadcast receiving means may be used for channel scanning and other broadcast receiving means may be used for viewing a program.

Embodiment 5 FIG.
FIG. 13 is a block diagram schematically showing a configuration of a digital broadcast receiving apparatus according to Embodiment 5 of the present invention.
Although the digital broadcast receiving apparatus according to the first embodiment includes two broadcast receiving units, the digital broadcast receiving apparatus according to the fifth embodiment includes only one broadcast receiving unit. That is, the digital broadcast receiver 1b shown in FIG. 13 includes a broadcast receiving antenna 11, a tuner / demodulator 12, a demultiplexer 13, a video / audio decoder 14, a graphics superimposing unit 15, Video output unit 16, audio output unit 17, operation input unit 18, channel selection control unit 19, channel scan control unit 25, current position detection antenna 26, current position detection unit 27, and broadcast area map A generation unit 28, a broadcast area map storage unit 29, a channel scan history determination unit 30, a channel scan history storage unit 39, and a broadcast service list generation unit 31 are provided.

The second broadcast receiving antenna 21, the second tuner / demodulating unit 22, the second demultiplexing unit 23, and the reception mode switching unit 24 provided in the digital broadcast receiving apparatus of FIG. It is not provided in the broadcast receiving apparatus 1b.
The antenna 11, the tuner / demodulator 12 and the demultiplexer 13 in FIG. 13 are the same as the first antenna 11, the first tuner / demodulator 12 and the first demultiplexer 13 in FIG. is there.
13 having the same reference numerals as those in FIG. 1 have the same or similar functions.

The channel scan control unit 25 performs channel scan using the tuner / demodulation unit 12. While the channel scan is performed, the output of the demultiplexing unit 13 is not sent to the video / audio decoding unit 14, the audio output unit 17 does not perform audio output, and the video output unit 16 also outputs video. I will not.

Since the digital broadcast receiving apparatus according to the fifth embodiment has only one system of broadcast receiving means, it switches between a mode for viewing a program and a mode for performing channel scanning.
The digital broadcast receiving apparatus according to the fifth embodiment can perform the channel scan processing described in the first embodiment, although there is a restriction that the channel scan cannot be performed while viewing a program. The same effect can be obtained.

For example, the channel scan in the digital broadcast receiving apparatus according to the fifth embodiment is performed as follows. For example, when viewing a program with a digital broadcast receiver, if the selected physical channel cannot be received, the mode may be automatically switched to the channel scan mode and the channel scan may be started. good. Alternatively, the user may perform a channel scan by operating himself. Furthermore, when the digital broadcast receiving apparatus is not used for viewing a program (when connected to a power source but the power switch is turned off), the channel scan control unit 25 detects this and the channel It is also possible to start scanning.

In addition, since the digital broadcast receiving apparatus according to the fifth embodiment has one tuner / demodulation unit and one demultiplexing unit, the cost can be reduced as compared with the digital broadcast receiving apparatus according to the first embodiment.

Although the fifth embodiment has been described as a modification to the first embodiment, the same modifications can be applied to the second, third, and fourth embodiments.

In Embodiments 1 to 5, a part of the digital broadcast receiving apparatus is realized by a processing circuit. The processing circuit may be dedicated hardware or a CPU that executes a program stored in a memory.
For example, in FIG. 1, the graphics superimposing unit 15, the channel selection control unit 19, the reception mode switching unit 24, the channel scan control unit 25, the current position detection unit 27, the broadcast area map generation unit 28, the channel scan history determination unit 30, The functions of the broadcast service list generation unit 31 may be realized by separate processing circuits, or the functions of the plurality of parts may be realized by a single processing circuit.
Similarly, in FIG. 13, the graphics superimposing unit 15, the channel selection control unit 19, the channel scan control unit 25, the current position detection unit 27, the broadcast area map generation unit 28, the channel scan history determination unit 30, and the broadcast service list generation. The functions of the unit 31 may be realized by separate processing circuits, or the functions of the plurality of parts may be realized by a single processing circuit.

When the processing circuit is a CPU, the functions of the above portions are realized by software, firmware, or a combination of software and firmware. Software or firmware is described as a program and stored in a memory. The CPU implements the functions of the respective units by reading and executing the program stored in the memory.
In addition, some of the functions of the above-described parts of the digital broadcast receiving apparatus may be realized by dedicated hardware, and the other part may be realized by software or firmware.

14 is a computer (indicated by reference numeral 100) including a single CPU, and the graphics superimposing unit 15, the channel selection control unit 19, and the reception of the digital broadcast receiving device 1 in FIG. Mode switching unit 24, channel scan control unit 25, current position detection unit 27, broadcast area map generation unit 28, broadcast area map storage unit 29, channel scan history determination unit 30, broadcast service list generation unit 31, and channel scan history storage unit 39 An example of a configuration for realizing this function is as follows: antennas 11, 21, and 26, first and second tuner / demodulators 12 and 22, first and second demultiplexers 13 and 23, video and audio A decoding unit 14, a video output unit 16, an audio output unit 17, and an operation input unit 18 are shown. Computer 100, antennas 11, 21, and 26, first and second tuner / demodulators 12 and 22, first and second demultiplexers 13 and 23, video / audio decoder 14, video output unit 16 The audio output unit 17 and the operation input unit 18 constitute a digital broadcast receiver.

A computer 100 shown in FIG. 14 includes a CPU 101, a memory 102, and a bus 103 that connects them.
The bus 103 includes first and second tuner / demodulators 12 and 22, first and second demultiplexers 13 and 23, a video / audio decoder 14, a video output unit 16, an operation input unit 18, In addition, an antenna 26 is connected.
A signal received by the antenna 26 is input to the CPU 101 via a receiving unit (not shown).

The memory 102 serves as the broadcast area map storage unit 29 and the channel scan history storage unit 39 in addition to storing programs.

The CPU 101 operates according to a program stored in the memory 102, and the graphics superimposing unit 15, the channel selection control unit 19, the reception mode switching unit 24, the channel scan control unit 25, the current position detection unit 27, and the broadcast area map generation unit. 28, the channel scan history determination unit 30 and the broadcast service list generation unit 31 are processed.
In processing, the CPU 101 includes first and second tuner / demodulators 12 and 22, first and second demultiplexers 13 and 23, a video / audio decoder 14, a video output unit 16, and an operation input unit 18. , And exchanges signals, data, or information with the antenna 26.

The content of processing by the CPU 101 is the same as that described in the first, second, third, or fourth embodiment. Data generated in the course of processing is held in the memory 102.

FIG. 15 shows a computer (indicated by reference numeral 100b) in which the processing circuit is a CPU, and includes a single CPU. The graphics superimposing unit 15, the channel selection control unit 19, and the channel of the digital broadcast receiving device 1b shown in FIG. When realizing the functions of the scan control unit 25, the current position detection unit 27, the broadcast area map generation unit 28, the broadcast area map storage unit 29, the channel scan history determination unit 30, the broadcast service list generation unit 31, and the channel scan history storage unit 39 An example of the configuration of the antennas 11 and 26, the first tuner / demodulator 12, the first demultiplexer 13, the video / audio decoder 14, the video output unit 16, the audio output unit 17, and the operation input unit Shown with 18. A computer 100b, antennas 11 and 26, a first tuner / demodulator 12, a first demultiplexer 13, a video / audio decoder 14, a video output unit 16, an audio output unit 17, and an operation input unit 18. A digital broadcast receiving apparatus is configured.

A computer 100 shown in FIG. 15 includes a CPU 101, a memory 102, and a bus 103 that connects them.
Connected to the bus 103 are a first tuner / demodulator 12, a first demultiplexer 13, a video / audio decoder 14, a video output unit 16, an operation input unit 18, and an antenna 26.
A signal received by the antenna 26 is input to the CPU 101 via a receiving unit (not shown).

The memory 102 serves as the broadcast area map storage unit 29 and the channel scan history storage unit 39 in addition to storing programs.

The CPU 101 operates in accordance with the program stored in the memory 102, and the graphics superimposing unit 15, the channel selection control unit 19, the channel scan control unit 25, the current position detection unit 27, the broadcast area map generation unit 28, the channel scan history determination. The processing of the unit 30 and the broadcast service list generation unit 31 is performed.
In the processing, the CPU 101 receives signals, data or data from the first tuner / demodulator 12, the first demultiplexer 13, the video / audio decoder 14, the video output unit 16, the operation input unit 18, and the antenna 26. Send and receive information.

The content of processing by the CPU 101 is the same as that described in the fifth embodiment. Data generated in the course of processing is held in the memory 102.

Although the present invention has been described above as a digital broadcast receiving apparatus, the digital broadcast receiving method implemented by the digital broadcast receiving apparatus also forms part of the present invention. In addition, a program for causing a computer to execute part or all of the processing in the digital broadcast receiving apparatus, part or all of the processing in the digital broadcast receiving method, and a computer readable recording the program Recording media also form part of the present invention.

11 First broadcast reception antenna, 12 First tuner / demodulation unit, 13 First demultiplexing unit, 14 Video / audio decoding unit, 15 Graphics superimposing unit, 16 Video output unit, 17 Audio output unit, 18 operation input unit, 19 channel selection control unit, 21 second broadcast receiving antenna, 22 second tuner / demodulation unit, 23 second demultiplexing unit, 24 reception mode switching unit, 25 channel scan control unit, 26 Current position detection antenna, 27 Current position detection section, 28 Broadcast area map generation section, 29 Broadcast area map storage section, 30 Channel scan history determination section, 31 Broadcast service list generation section, 39 Channel scan history storage section, 40 Broadcast signal reception Department.

Claims (15)

1. A digital broadcast receiver having at least one tuner / demodulator for selecting a physical channel and demodulating a broadcast signal of the selected physical channel,
   A current position detection unit for detecting a current position of the digital broadcast receiver;
   A channel scan controller for performing a channel scan to determine whether each physical channel is receivable using the at least one tuner / demodulator;
   Based on the result of the channel scan, a broadcast area map generator that generates information indicating an area that can be received for each physical channel;
   A broadcast service list generating unit that generates a service list indicating a broadcast service that can be received at each point based on the generated information indicating the receivable area;
   A channel scan history storage unit that stores channel scan history information indicating the history of the channel scan for each mesh area;
   The channel scan control unit performs channel scan based on information about a mesh area to which a current position detected by the current position detection unit belongs among the channel scan history information stored in the channel scan history storage unit. A digital broadcast receiver characterized by determining a physical channel to be tuned.
2. The channel scan history information stored in the channel scan history storage unit includes information indicating whether or not each physical channel has been selected by channel scanning in each mesh area. Item 4. The digital broadcast receiver according to Item 1.
3. Physics that has not been selected by channel scanning in a mesh area to which the current position detected by the current position detection unit belongs with reference to the channel scan history information stored in the channel scan history storage unit A channel scan history determination unit that outputs a list including channels as an unselected physical channel list;
   The digital broadcast receiving apparatus according to claim 2, wherein the channel scan control unit performs a channel scan on a physical channel included in the unselected physical channel list.
4. The channel scan history information stored in the channel scan history storage section indicates that the channel has not been selected when each physical channel has never been selected in the channel scan in each mesh area. When each physical channel has been selected more than once in the channel scan in each mesh area, the date when each physical channel was last selected in the channel scan in the mesh area The digital broadcast receiving apparatus according to claim 1, further comprising information indicating a month.
5. With reference to the channel scan history information stored in the channel scan history storage unit, the channel has not been selected in the channel scan in the mesh area to which the current position detected by the current position detection unit belongs, Or a channel scan history determination unit that outputs a list including physical channels whose elapsed time from the last channel selection in the mesh area is equal to or longer than a preset period as an unselected physical channel list. Have
   The digital broadcast receiving apparatus according to claim 4, wherein the channel scan control unit performs a channel scan on a physical channel included in the unselected physical channel list.
6. The channel scan history information stored in the channel scan history storage unit is:
   If the channel scan in each mesh area has never been completed, it contains information indicating that the channel scan has never been completed, and the channel scan in each mesh area may have been completed more than once In the mesh area, scan completion history information including information indicating the date or month when the channel scan was last completed, and
   Channel selection history information indicating whether or not each physical channel has been selected,
   The channel selection history information is
   When the channel scan in each mesh area has never been completed, the channel scan in each mesh area includes information indicating whether each physical channel has been selected,
   When the channel scan in each mesh area has been completed once or more, information indicating whether or not each physical channel is selected during the channel scan in each mesh area is included. The digital broadcast receiver according to claim 1.
7. With reference to the channel scan history information stored in the channel scan history storage unit,
   When the scan completion history information includes information indicating that the channel scan in the mesh area to which the current position detected by the current position detection unit belongs has never been completed, it has been selected. Output a list of non-selected physical channels as an unselected physical channel list,
   When the scan completion history information includes information indicating the date or month when the channel scan was last completed, and the elapsed time since the channel scan was last completed is equal to or longer than a preset period, all A channel scan history determination unit that outputs a list of physical channels as an unselected physical channel list,
   The digital broadcast receiving apparatus according to claim 6, wherein the channel scan control unit performs a channel scan on a physical channel included in the unselected physical channel list.
8. The channel scan control unit updates the channel scan history information for the mesh area to which the current position belongs when the channel selection is executed when channel selection is performed in the channel scan. The digital broadcast receiver according to any one of claims 1 to 7.
9. In the channel scan for each mesh area, when the channel selection for all physical channels is completed, the channel scan control unit displays information indicating the date or month of the end in the mesh area. The digital broadcast receiving apparatus according to claim 6 or 7, wherein the channel scan history information is updated as new information indicating a date or month last completed.
10. The said mesh area is formed by dividing | segmenting a broadcast receiving object area | region into a grid | lattice form by the line parallel to a meridian and the parallel to a latitude line, The any one of Claim 1 to 9 characterized by the above-mentioned. The digital broadcast receiver as described.
11. 11. The broadcast area map generation unit generates coordinates of a rectangular coordinate system of polygonal vertices approximating a receivable area as information representing the receivable area. The digital broadcast receiver described in 1.
12. The at least one tuner / demodulator includes a plurality of tuners / demodulators;
    The operation mode of the plurality of tuners / demodulators is the first operation mode in which all the plurality of tuners / demodulators are used for program viewing, or one tuner / demodulator of the plurality of tuners / demodulators. A reception mode switching unit that is used for channel scanning, and the tuner / demodulation unit other than the one tuner / demodulation unit switches to a second operation mode used for program viewing,
    The channel scan control unit instructs the reception mode switching unit to switch to the second operation mode when performing the channel scan. The digital broadcast receiver described in 1.
13. A digital broadcast receiving method in a digital broadcast receiving apparatus having at least one tuner / demodulator for selecting a physical channel and demodulating a broadcast signal of the selected physical channel,
    Detecting the current position of the digital broadcast receiver,
    Perform a channel scan to determine whether each physical channel is receivable,
    Based on the channel scan result, information indicating the receivable area for each physical channel is generated, and based on the generated information indicating the receivable area, a service list indicating a broadcast service that can be received at the current position is generated. And
    Store channel scan history information indicating the history of the channel scan for each mesh area,
    A digital broadcast receiving method, wherein a physical channel to be selected in a channel scan is determined based on information on a mesh area to which a current position belongs in the channel scan history information.
14. A program for causing a computer to execute processing in the digital broadcast receiving method according to claim 13.
15. A computer-readable recording medium on which the program according to claim 14 is recorded.

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