JP6723435B2 - Digital broadcast receiving apparatus, digital broadcast receiving method, program, and recording medium - Google Patents

Description

The present invention relates to a mobile digital broadcast receiving apparatus, for example, a digital broadcast receiving apparatus mounted on a moving 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 the processing in the digital broadcast receiving apparatus or method, and a recording medium recording the program.

When a mobile body equipped with a digital broadcast receiving device, for example, a vehicle, moves from inside the receivable area of the physical channel being received by the digital broadcast receiving device to outside the receivable area, the physical channel that was normally received. You will not be able to view the broadcasting services provided by. In this case, the user manually operates the digital broadcast receiving apparatus to perform a channel scan to detect receivable physical channels, 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 receivers having a broadcast signal tuning function that do not require the 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. In addition to the above, the other receiving means is provided with a function switching means for periodically (for example, at a time interval of 15 minutes) seeking a physical channel to switch the second function of obtaining information about channel selection, and The acquired information is stored and immediately switched to a receivable physical channel when the receivable physical channel changes with movement (for example, claim 2 of patent document, abstract).

The digital broadcast receiving device 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 broadcasting area nationwide. An area information storage unit that has been stored and a channel switching unit that switches the receiving channel based on the area information corresponding to the current position of the vehicle are provided, and the receiving channel is automatically switched.

A digital broadcast receiving device disclosed in Patent Document 3 is a broadcast area map storage unit that stores broadcast area map generated area information together with a broadcast area map indicating 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 reference by referring to the generated area information, and based on the information of the broadcast area map non-generated area determination unit Determines whether to perform a channel scan at the location.

JP 2005-217681 A (claim 2) JP, 2013-138287, A (claim 1, paragraph 0028, 0033, Drawing 1, Drawing 2). JP, 2013-225885, A (paragraph 0018, 0024).

However, in the digital broadcast receiving apparatus described in Patent Document 1, since seeks (channel scans) of physical channels are periodically performed at fixed time intervals, the result of the channel scan is a maximum of the fixed time intervals described above. However, there is a problem in that the physical channel selected by using the result of the channel scan may not be appropriate because it becomes old.

It is possible to increase the probability that the selected physical channel will be appropriate by setting the above fixed time interval short, but in such a case, a program based on a high-quality received signal is used. There is a problem that the period for performing diversity reception that enables viewing is shortened.

Furthermore, even if the mobile body equipped with the digital broadcast receiving device does not move, the channel scan is regularly performed, and there are many useless channel scans that do not contribute to the improvement in the accuracy of automatic channel switching. Therefore, there is a problem that the operation becomes inefficient.

Since the digital broadcast receiving device described in Patent Document 2 does not have means for updating the area information stored in the area information storage unit, the broadcast transmission output of the transmitting station is changed or a new transmitting station is installed. There was a problem that it could not respond to changes in the coverage area due to relocation, abolition, etc.

In addition, there is a problem that a large storage area is required to store area information in which a set of broadcasting station name, TSID, affiliated station ID, reception mode, and physical channel is set for each mesh.

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

The present invention has been made in order to solve the above-mentioned problems of the prior art, and an object thereof is to be able to more appropriately determine a physical channel to be selected by channel scanning, and to perform automatic channel scanning. This is to reduce the amount of information stored for control and to enable efficient channel scanning.

A digital broadcast receiving apparatus according to the present invention,
A digital broadcast receiving apparatus having at least one tuner/demodulation unit for selecting a physical channel and demodulating a broadcast signal of the selected physical channel,
A current position detector for detecting the current position of the digital broadcast receiving device,
A channel scan controller that performs a channel scan to determine whether each physical channel is receivable using the at least one tuner/demodulator,
A broadcast area map generator that generates information indicating a receivable area for each physical channel based on the result of the channel scan;
A broadcast service list generation unit that generates a service list indicating broadcast services receivable at the current position 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 a channel scan based on information about a mesh area to which the current position detected by the current position detection unit belongs, among the channel scan history information stored in the channel scan history storage unit. Decide the physical channel to tune in ,
The channel scan history information stored in the channel scan history storage unit is
When the channel scan in each mesh area has never been completed, it includes the information indicating that the channel scan has never been completed, and the channel scan in each mesh area has been completed once or more. In that case, within the mesh area, scan completion history information including information indicating the date or month when the channel scan was last completed,
Including tuning history information indicating whether or not each physical channel has been selected,
The tuning history information is
When the channel scan in each mesh area has never been completed, including the information indicating whether or not each physical channel has been selected by the channel scan in each mesh area,
When a channel scan in each mesh area has been completed once or more, it is characterized by including information indicating whether or not each physical channel is selected during execution of the channel scan in each mesh area. ..

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 scanning control can be small. Further, it is possible to reduce the number of physical channels subject to channel scanning or to reduce the frequency of channel scanning, so that channel scanning can be performed efficiently.

1 is a block diagram schematically showing a configuration of a digital broadcast receiving apparatus according to Embodiment 1 of the present invention. FIG. 3 is a diagram showing, in a tabular format, a structure of information representing a broadcast area map stored in a broadcast area map storage unit of the digital broadcast receiving apparatus according to the first embodiment. 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. 6 is a flowchart showing a broadcast service list generation process by a broadcast service list generation unit in FIG. 1. 6 is a flowchart showing a channel scan history determination process by the channel scan history determination unit in FIG. 1. 6 is a flowchart showing a channel scan process performed by the channel scan controller of FIG. 1. It is a figure which shows an example of the channel scan history information hold|maintained at the channel scan history storage part of the digital broadcast receiving apparatus which concerns on Embodiment 2 of this invention in a table format. 9 is a flowchart showing channel scan history determination processing by the channel scan history determination unit according to the second embodiment. It is a figure which shows an example of the channel scan history information hold|maintained at the channel scan history storage part of the digital broadcast receiving apparatus which concerns on Embodiment 3 of this invention in a table format. 16 is a flowchart showing channel scan history determination processing by the channel scan history determination unit according to the third embodiment. It is a figure which shows an example of the channel scan history information hold|maintained at the channel scan history storage part of the digital broadcast receiving apparatus which concerns on Embodiment 4 of this invention in a table format. It is a block diagram which shows roughly the structure of the digital broadcast receiving apparatus which concerns on Embodiment 5 of this invention. It is a block diagram which shows an example of a structure which implement|achieved a part of digital broadcast receiving apparatus of FIG. 1 with the computer. FIG. 14 is a block diagram showing an example of a configuration in which a part of the digital broadcast receiving apparatus in FIG. 13 is realized by a computer.

Embodiment 1.
FIG. 1 is a block diagram schematically showing the configuration of a digital broadcast receiving apparatus 1 according to the first embodiment of the present invention. The digital broadcast receiving apparatus 1 shown in FIG. 1 includes a first broadcast receiving antenna 11, a first tuner/demodulation unit 12, a first demultiplexing unit 13, a video/audio decoding unit 14, The graphics superimposing unit 15, the video output unit 16, the audio output unit 17, the operation input unit 18, and the tuning control unit 19 are provided. The digital broadcast receiving apparatus 1 further includes a second broadcast receiving antenna 21, a second tuner/demodulation unit 22, a second demultiplexing unit 23, a reception mode switching unit 24, and a channel scan control unit 25. An antenna 26 for detecting the current position, a current position detecting section 27, a broadcast area map generating section 28, a broadcast area map storing section 29, a channel scan history determining section 30, a channel scan history storing section 39, and a broadcast service. And a list generation unit 31.
The first tuner/demodulation unit 12, the second tuner/demodulation unit 22, and the reception mode switching unit 24 may be configured in one broadcast signal reception unit 40.

The operation input unit 18 is used when the user inputs an operation such as turning the power on/off, requesting presentation of a broadcast service list, and selecting a channel.

The current position detection unit 27 detects the current position of the digital broadcast receiving device 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, GPS antenna) 26 for current position detection, and information indicating the current position, for example, Outputs information indicating longitude and latitude.

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

The reception mode switching unit 24 switches the reception mode of the digital broadcast receiving apparatus 1 between the double tuner mode and the single tuner mode according to the switching control signal from the channel scan control unit 25.
In the single tuner mode (first operation mode), the two systems of broadcast receiving means tune to the same physical channel and perform diversity processing on the reception signals of the two systems of broadcast receiving means. By the diversity processing, one TS (transport stream) having high reception stability is output from the first tuner/demodulation unit 12.
In the double tuner mode (second operation mode), the broadcast receiving means (each of the first tuner/demodulation unit 12 and the second tuner/demodulation unit 22) of each system independently selects physical channels. ..

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 receives the diversity of 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 demultiplexing unit 13 separates the TS generated by the first tuner/demodulation unit 12 into video data and audio data based on PID (packet identification information), and the video data and the audio data are video/audio data. It is output to the audio decoding unit 14. The first demultiplexer 13 also supplies the section data to the channel scan controller 25. When the section data is interrupted, the first demultiplexer 13 also notifies the channel selection controller 19 and the channel scan controller 25 of this.

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 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 graphics data to be superimposed represents, for example, a broadcast service list described later.
The video output unit 16 displays a video represented by a video signal output from the graphics superimposing unit 15 on a display unit (not shown) or outputs a 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 that state, the channel scan control unit 25 operates the second tuner/demodulation unit 22 and the second demultiplexing unit 23. Perform a channel scan using.
That is, in the double tuner mode, the broadcast signal received by the first broadcast receiving antenna 11 is transmitted to the first tuner/demodulator 12, the first demultiplexer 13, and the video/audio decoder 14. It is converted to 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, superposed 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 transmitted 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/demodulation unit 22 sequentially selects the 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 whether or not a sufficiently large received signal can be obtained when the physical channel is tuned, that is, the power level of the received signal is larger than a predetermined value. This is performed based on the result of the determination as to whether or not the frame lock has been performed, and the result of the determination as to whether or not the PSI/SI information has been acquired.

The channel scan using the second tuner/demodulation unit 22 is executed while the viewer is not aware while the program is being viewed by the first tuner/demodulation unit 12 (on the other side of program viewing). It is executed), so it is also called "back channel scan".

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

Information (tuning history information) indicating whether or not each physical channel has been selected by a channel scan is recorded in the channel scan history storage unit 39.
The fact that the channel has been selected by the channel scan is called "tuned". A channel that has never been selected by a channel scan is called an "unselected station." Further, the tuning history information indicating whether or not the channel has been selected by the channel scan may be referred to as a "tuned flag".
The phrase "has not been selected by a channel scan" generally means that the digital broadcast receiving device has never been selected since the start of use. However, for some reason, if the storage contents of the broadcast area map storage unit 29 and the channel scan history storage unit 39 are erased due to a reset, for example, it has never been selected after the deletion. means.

The channel scan is performed at a plurality of points along with the movement of the mobile body equipped with the digital broadcast receiving device.
The broadcast area map generator 28 generates a broadcast area map based on the results of channel scans performed at a plurality of points. Specifically, the broadcast area map generator 28 has information indicating the point (the current position indicated by the position information from the current position detector 27) at which the channel scan has been selected, and the channel scan selection at each point. A broadcast area map is generated based on information indicating whether or not each physical channel is determined to be receivable at the station and broadcast service information regarding the broadcast content 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 has been viewed until then, for example, when the reception state of the broadcast service provided on the physical channel currently being received deteriorates as the mobile unit moves. It is used to automatically switch to another physical channel that provides the same program as.

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

The coverage area of FIG. 3 is approximated by a polygon. As the coordinates indicating the vertices of the polygon, the coordinates of the vertices of the polygon are recorded in the order of clockwise selection of the vertices of the polygon. For example, for 13ch, as shown in FIG. 3, the vertices of the polygon indicated by the reference numeral 50 Point10, Point20, ... Pointm are sequentially selected, respective coordinates _{(x 10, y 10),} (x 11, y ₁₁ ), (x ₁₂ , y ₁₂ ),..., (x _1m , y _1m ) are recorded in the order of selection of the corresponding vertices.
Vertex coordinates _{(x 10, y 10),} (x 11, y 11), ..., (x 1m, y 1m) is orthogonal coordinate system axes which X coordinate axis of longitude, the axis of the latitudinal direction is defined as Y axis Indicated by.

The TS name is recorded as a part of the broadcast area map, ISDB-T (Integrated Services Digital Broadcasting-Terrestrial), DVB-T (Digital Video Broadcasting-Terrestrial), DVB-HiddenBroadcasting, and DVB-HiddenBroadcasting. (Digital Terrestrial Multimedia Broadcast), ATSC (Advanced Television Systems Commitee), and other digital broadcasting standards.
The name of the ensemble is recorded as part of the broadcast area map in the digital broadcasting standard such as DAB (Digital Audio Broadcast), DAB+ (Digital Audio Broadcast plus), and DMB (Digital Multimedia Broadcasting).
In either case, one TS or one ensemble is transmitted by one physical channel, and a plurality of broadcast services are included in the transmission information. The 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 normally there are multiple broadcast service names.

As the information indicating the relay station CH and the information indicating the affiliated station CH, for example, information acquired from section data (for example, PSI/SI information) received by the channel scan is recorded.
By recording the information indicating the relay station CH and the information indicating the affiliated station CH as 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. It is possible to grasp the likely alternative physical channel and realize automatic switching in a short time.
In addition, there is a high possibility that physical channels having 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 condition of the broadcast signal deteriorates, the broadcast area map can be referenced to identify the alternative physical channel that is likely to be broadcasting the same program. It is possible to realize automatic switching 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 history of channel selection of each physical channel in the channel scan performed in the mesh area. An example of the channel scan history information is shown in FIG. The channel scan history information shown in FIG. 4 includes tuning history information indicating whether or not each physical channel has been selected by a channel scan in each mesh area, that is, a tuning completion flag.

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

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

When the channel scan history determination unit 30 outputs the unselected station physical channel list, the channel scan control unit 25 starts the channel scan in response to this. In this case, the channel scan control unit 25 sequentially selects one or more physical channels included in the unselected physical channel list output from the channel scan history determination unit 30. When the channel scan control unit 25 selects one physical channel and determines whether it is receivable or not, 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, each time the channel scan control unit 25 selects one physical channel, the channel scan control unit 25 determines 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 on the part corresponding to the specified number and corresponding to the selected physical channel is rewritten from "unselected" to "selected".

For example, "unselected station" is represented by "0", and "selected station" is represented by "1". In that case, the tuning history information for one physical channel is represented by 1 bit, and the number of bits equal to the number of physical channels is sufficient for one mesh area. For example, when the target of the channel scan is 40 physical channels in total from 13 channels to 52 channels, 40 bits, that is, 5 bytes is 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 physical channels receivable at the current position.
The generation and presentation of the broadcast service list is performed in response to, for example, when the user requests the presentation of the broadcast service list using the operation input unit 18.

FIG. 5 is a flowchart showing a process of generating and presenting a broadcast service list by the broadcast service list generating 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), first, the process of step S12 is performed.
In step S12, information indicating a physical channel receivable 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, from the information indicating the physical channel receivable at the current position, the broadcast service information regarding the broadcast content of the physical channel is acquired, and the information is acquired as the information indicating the broadcast service receivable at the current position. A broadcast service list is generated based on the acquired information, and the generated broadcast service list is supplied to the graphics superimposing unit 15.
This is the end of the process of generating 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 it 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 displayed broadcast service list and selects (tunes) the broadcast service to be viewed on the operation input unit 18.

When a broadcast service channel selection request from 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 to perform channel selection. Determines the physical channel to be used and issues a tuning instruction.
The instruction for channel selection is sent to the first tuner/demodulator 12 in the double tuner mode, and 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 either mode, the video output unit 16 and the audio output unit 17 are based on the signals output via the first tuner/demodulation unit 12, the first demultiplexing unit 13, and the video/audio decoding unit 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 the one that was being watched when the reception state of the physical channel currently being received deteriorates as the moving body moves. It is used for automatic switching to another physical channel offering a program.

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

The tuning 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 information shown, it is determined whether the reception state of the broadcast signal has deteriorated. When it is determined that the reception condition of the broadcast signal has deteriorated, the tuning control unit 19 receives another physical channel that can be received at the current position, is broadcasting the same program, or is likely to be broadcasting the same program. Instruct to automatically switch 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 the same broadcasting service is found, switching to the physical channel is instructed. .. If the physical channel of the relay station or affiliated station of the broadcast station that has been received until then is found, 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/demodulation unit 12 and the second tuner/demodulation unit 22 in the single tuner mode, and is given to the first tuner/demodulation unit 12 in the double tuner mode.

Hereinafter, the channel scan history determination processing by the channel scan history determination unit 30 will be described in more detail.
FIG. 6 is a flowchart showing a procedure of channel scan history determination processing by the channel scan history determination unit 30.
The processing of FIG. 6 is desirably executed periodically, for example. It is desirable that the execution cycle can be changed according to the moving speed of the mobile body equipped with the digital broadcast receiving apparatus. For example, it is desirable to lengthen the execution cycle when the moving speed is low and to shorten the execution cycle when the moving speed is high. As an example, if the moving speed is an average speed, it may be executed once every 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 the 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 record (the channel scan history information specified in step S22). Of these, the part 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, and determines whether or not one or more unselected station physical channels exist in the mesh area, that is, channel selection. It is determined whether or not there is at least one physical channel whose completed flag has a value indicating "unselected station".

If it is determined in step S24 that one or more unselected station physical channels exist, the process proceeds to step S25. If not, the process ends.
In step S25, the channel scan history determination unit 30 extracts one or more unselected station physical channel numbers, lists the extracted unselected station physical channel numbers, and performs a channel scan as an unselected station physical channel list. It is supplied to the control unit 25.
This completes the channel scan history determination.

Upon receiving the unselected station physical channel list, the channel scan control unit 25 starts channel scanning. Therefore, first, the reception mode switching unit 24 is instructed to switch to the double tuner mode. In the double tuner mode, the first tuner/demodulation unit 12 performs an operation for viewing, and at the same time, a channel scan using the second tuner/demodulation unit 22 is performed.

Hereinafter, the channel scan processing by the channel scan control unit 25, which is performed in response to the supply of the unselected station physical channel list from the channel scan history determination unit 30, will be described with reference to FIG. 7.
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 the physical channel to be selected. This determination is made by selecting one of the physical channels (unselected station physical channels extracted by the channel scan history determination section 30) in the list of unselected station physical channels sent from the channel scan history determination section 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 perform tuning on the physical channel selected in step S33. In response to this, the second tuner/demodulation unit 22 executes tuning to the physical channel selected in step S33.

After step S34, a determination process is performed to determine whether 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 on the tuned physical channel. This determination is made, for example, based on whether or not the power level of the received signal is higher than a predetermined value.
If it is determined that there is a broadcast signal, the operation proceeds to step S36. If not, the process proceeds to step S40.

In step S36, the channel scan control unit 25 makes a 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. It is determined whether or not it is a desired digital broadcast wave to be received.
If the frame is locked (YES in S36), the process proceeds to step S37. If not, the process proceeds to step S40.

In step S37, the channel scan control unit 25 starts the PSI/SI section filtering process and tries to acquire PSI/SI information.
Then, in the next step S38, the channel scan control unit 25 determines whether or not the PSI/SI information has been acquired within a predetermined time. If the PSI/SI information can be acquired within the predetermined time, the process proceeds to step S39. If not, 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 the signal was receivable, the process proceeds to step S39, and any of the determination results in steps S35, S36, and S38. If the answer is NO, it means that the message could not be received, and the process proceeds to step S40.

In step S39, the channel scan control unit 25 extracts the broadcast service information from the acquired PSI/SI information, and outputs the information indicating the physical channel and the information indicating the power level of the received signal together with the information indicating the current position in the broadcast area map. The generation unit 28 is notified.
The broadcast area map generator 28 generates or corrects the broadcast area map based on the information received from the channel scan controller 25, and updates the broadcast area map stored in the broadcast area map storage 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 the information indicating that the physical channel selected in step S33 could not be received at the current position, together with the information indicating the current position.
The broadcast area map generator 28 generates or corrects the broadcast area map based on the information received from the channel scan controller 25, and updates the broadcast area map stored in the broadcast area map storage 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 calculated from the current position information, and the channel selection flag of the corresponding physical channel column in the row of the corresponding mesh area number is set to "selected". Update to.

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

If there is an unselected station physical channel included in the unselected station physical channel list that has not yet been selected (NO in S42), the process returns to step S33. In step S33, the channel scan control unit 25 determines the physical channel to be selected next. That is, one of the unselected station physical channels included in the unselected station physical channel list sent from the channel scan history determination unit 30 is selected as a physical channel that has not been selected yet.
As a result, until the selection of all unselected physical channels is completed, the physical channel is determined (step S33), the tuning by the second tuner/demodulation unit 22 and the broadcast signal by the channel scan control unit 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 station physical channel list from the channel scan history determination unit 30 has been described above.
The channel scan may be executed even when the network configuration information, the broadcast service configuration information, etc. change. To this end, the channel scan control unit 25 acquires section data (for example, PSI/SI information) from the first demultiplexing unit 13 while viewing a program, and uses the section data to obtain network configuration information and broadcast service configuration information. Etc. are acquired and these changes are detected.

Changes in network configuration, broadcast service configuration, etc. include loss of broadcast service, change of transmission physical channel, change of network identification value, change of broadcast service identification value, change of network name, change of TS name, change of ensemble name. , And changes in broadcast service names are included. In these cases, it is possible that the broadcast service configuration has 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 according to changes in the network configuration, broadcast service configuration, etc., and the broadcast area map is updated.

The channel scan in the case of detecting the change in the network configuration, the broadcast service configuration, etc. can be performed by the same procedure as shown in FIG. However, the target of the channel scan is not limited to the unselected station physical channels, but all physical channels are different. That is, in step S33, one physical channel is selected from all the physical channels.

As described above, according to the digital broadcast receiving apparatus in the first embodiment, as the channel scan history information, it is determined whether or not each physical channel has been selected in the channel scan in each mesh area. Information (a flag indicating that a channel has been selected) is stored, and a physical channel that has not been selected by a channel scan in the mesh area (a physical channel that has not been selected) is being moved while moving in a certain mesh area. Since the channel scan is performed only when the channel scan exists, it is possible to reduce unnecessary execution of the channel scan (that is, it does not contribute to the improvement of the accuracy of the automatic channel switching). As a result, the channel scan operation becomes efficient. In addition, it is possible to increase the period in which diversity processing is performed. Therefore, it is possible to increase the period during which a program is viewed by generating a highly stable received signal by diversity processing.

Further, since only the physical channels (unselected physical channels) that have not been selected by the channel scan in the past at the current position are targeted for the channel scan, it is possible to further reduce the unnecessary execution of the channel scan.

In addition, since it is possible to express with 1 bit whether or not each physical channel has been selected (whether or not the channel has been selected) in the channel scan in each mesh area, it is possible to store the channel scan history information. It requires less storage space.

Furthermore, since the broadcast area map including the broadcast service information is automatically generated by the channel scan, when moving the area where the broadcast area map is created, it is possible to present the user with a list of broadcast services that can be received at that point. Therefore, it is possible to enhance the convenience when mounted on a mobile body.

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

Furthermore, when the information indicating the receivable area included in the broadcast area map is the information indicating the coordinates of the vertices of a polygon that approximates the receivable area, it indicates whether or not each mesh area is located within the receivable area. The amount of information is smaller than that in the case of storing information, and the storage area for recording the information indicating the receivable area is small.

Furthermore, since 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, the broadcast transmission output of the transmitting station is changed or It can respond to changes in the coverage area due to new construction, relocation, abolition, etc.

In addition, in the digital broadcast receiving apparatus according to the first embodiment, even when moving in 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. If the channel scan is executed at that time, 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.
In the first embodiment, as channel scan history information, a channel selection completion flag is stored for each physical channel for each mesh area. In that case, once set to “tuned”, the state set to “tuned” is maintained thereafter, and channel scanning is not performed. On the other hand, over a long period of time, the reception status may change due to, for example, a tall building becoming difficult to receive broadcast waves, or 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, the problem that the change in the situation is not reflected in the broadcast area map occurs. 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 targeted for the channel scan. Therefore, in the second embodiment, for each mesh area, the date when the channel scan was last executed is recorded for each physical channel, and when a preset period (set period) has elapsed from the recorded execution date, The channel scan will be performed again for the physical channel. It is desirable to set the above-mentioned set period to, for example, several months.
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 the second embodiment is the same as that of the digital broadcast receiving apparatus according to the first embodiment shown in FIG.

FIG. 8 is a diagram showing an example of channel scan history information stored in the channel scan history storage unit 39 of the digital broadcast receiving apparatus according to the second embodiment in a table format. The channel scan history information in FIG. 8 is information about each mesh area as in the first embodiment, and includes tuning history information about each of a plurality of physical channels. The tuning history information indicates that when the corresponding physical channel has never been selected by the channel scan in the corresponding mesh area (when it is “unselected station”) (“unselected station”). )), and if the corresponding physical channel has been selected once or more by the channel scan in the corresponding mesh area, it indicates the channel selection execution date.
The tuning execution date referred to here is the date when the corresponding physical channel was last selected by the channel scan in the corresponding mesh area.

The tuning history information is set to a value indicating “unselected station”, for example, “−1” as an initial value.
When the tuning history information indicates a tuning execution date, the total date starting from a certain standard day is represented by 2 bytes. Allocating 2 bytes (16 bits) can express which day of about 180 years. This period is sufficient for the operation of the digital broadcast receiver.

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

The channel scan history determination unit 30 periodically performs the channel scan history determination processing as in the first embodiment.
FIG. 9 is a flowchart showing a procedure of channel scan history determination processing by the channel scan history determination unit 30 according to the second embodiment. The processing of steps S21, S22, S23, and S25 in FIG. 9 is the same as that 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 indicates the channel selection execution date, and the elapsed time from the channel selection execution date is equal to or longer than the set period. It is judged whether or not there is a physical channel that is.
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 (YES), the process proceeds to step S52, and if not, the process proceeds to step S53.

In step S52, the channel selection history information about the physical channel whose elapsed period from the channel selection execution date is determined to be equal to or longer than the set period in step S51 is rewritten to a value indicating "unselected station". When there is a physical channel for which the elapsed time from the channel selection execution date is judged to be longer than the set period, the channel selection history information for all physical channels is rewritten to the value indicating "unselected station". 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 at least one physical channel whose channel selection history information is a value indicating "unselected station". The physical channels whose tuning history information has a value indicating "unselected station" include the physical channels whose channel selection history information is rewritten to "unselected station" in step S52.
If it is determined in step S53 that there is at least one physical channel whose tuning history information is "unselected station", the process proceeds to step S25. If not, the process ends.

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

As described above, in the second embodiment, the channel scan history determination unit 30 refers to the channel scan history information about the mesh area to which the current position belongs and selects the channel by the channel scan in the mesh area to which the current position belongs. It has never been played (a value indicating "unselected station" is recorded as channel selection history information), or the elapsed time since the channel was last selected by a channel scan in the mesh area was set in advance. A list including physical channels that are equal to or longer than the period (the period elapsed from the channel selection execution date is equal to or longer than the set period) is output as an unselected station physical channel list.

When the channel scan history determination unit 30 outputs the unselected station physical channel list, the channel scan control unit 25 starts the channel scan in response to this.
The channel scan is performed by the same procedure as described with reference to FIG. 7 in the first embodiment. However, not only when the unselected channel physical channel list includes only physical channels that have never been selected by the channel scan, only physical channels whose elapsed time from the channel execution date is the set period or more May be included, and there may be cases where both physical channels that have never been selected by a channel scan and physical channels whose elapsed time from the execution date of the channel selection is longer than the set period are included. 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. At this time, the physical channels included in the unselected station physical channel list only include physical channels in which a value indicating "unselected station" is recorded (at the start of the process in FIG. 9) as channel selection history information.
On the other hand, after the general channel scan is performed, most of the physical channels included in the unselected station physical channel list (at the start of the process in FIG. 9) have the elapsed period from the channel selection execution date equal to or longer than the set period. It consists of only the physical channel However, since there is a physical channel that was not selected for some reason in the first channel scan, a value indicating "unselected" is recorded as the selection history information and the execution of the channel selection. There is a possibility that a physical channel whose elapsed period from the day is longer than the set period is included in the same unselected station physical channel list.

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

The channel scan periodically performed according to the channel scan history determination processing has been described above. Although the channel scan performed according to the change in the network configuration, the broadcast service configuration and the like has been described in the first embodiment, the channel scan according to the change in the network configuration, the broadcast service configuration and the like also in the second embodiment. It can be carried out. In this case, the channel scan is performed not only on the physical channels whose elapsed time from the channel selection execution date is the set period or more but also on all the physical channels.
Even when a channel scan is performed according to changes in the network configuration, the broadcast service configuration, etc., when each physical channel is selected, the selection history information of that 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 the physical channels are selected once or more by the channel scan in the mesh area to which the current position belongs, In the channel scan history determination process that is performed, if a physical channel whose elapsed time since the channel was last selected is the set period or more is found in the channel scan in the mesh area to which the current position belongs, such a physical channel is found. A channel scan is performed as a target. Therefore, when the reception status changes, the status change can be reflected in the broadcast area map.
Further, the time required for the channel scan can be shortened as compared with the case where the channel scan is performed for all the physical channels on a regular basis. As a result, the channel scan operation becomes efficient. In addition, it is possible to increase the period in which diversity processing is performed.

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

The third embodiment is intended to solve this problem. The configuration of the digital broadcast receiving apparatus according to the third embodiment is the same as that of the digital broadcast receiving apparatus of the first embodiment 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 of FIG. 10 is information about each mesh area, as in Embodiments 1 and 2, and includes scan completion history information about the mesh area and tuning history about each of a plurality of physical channels. Contains information.

For the scan completion history information for each mesh area, if the channel scan in the mesh area has never been completed (when it is “incomplete”), the fact that it is “incomplete” is indicated. If 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 last completed within the mesh area.
The scan completion history information is set to a value indicating “incomplete”, for example, “−1” as an initial value.
When the scan completion history information indicates a scan completion date, the total date starting from a certain standard day is represented by 2 bytes.

The channel selection history information for each physical channel is also called a channel selection flag, and indicates whether or not the physical channel has been channel-selected.
More specifically, the channel selection flag for each physical channel is such that, if the channel scan in the corresponding mesh area has never been completed, the channel scan in the corresponding mesh area indicates that the corresponding physical channel is It indicates whether or not the channel has been tuned, and if the channel scan in the corresponding mesh area has been completed once or more, 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 channel", for example, "0". In that state, when each physical channel is selected by the channel scan, the channel selection flag for the physical channel is updated to a value indicating "channel selection", for example, "1".
When the channel selection completion flag is set to “selection completed” for all physical channels, the date including the time point is recorded as the “scan completion date”.
The above channel scan history information is updated by the channel scan control unit 25.

The channel scan history determination unit 30 periodically performs the channel scan history determination processing as in the first embodiment.
FIG. 11 is a flowchart showing a procedure of channel scan history determination processing by the channel scan history determination unit 30 of the third embodiment. The processing of steps S21, S22, S23, and S25 in FIG. 11 is the same as that 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 "not completed" is recorded as the scan completion history information.
When a value indicating "not completed" is recorded as the scan completion history information in step S61 (YES), the process proceeds to step S25, otherwise, that is, the scan completion history information represents the scan completion date. If so, 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 period elapsed from the scan completion date is equal to or longer than the set period in step S62 (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 station". That is, in the channel scan history information on the mesh area, all the channel selection flags for each physical channel are rewritten to values indicating "unselected channel".

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 the list of physical channels for which the selected channel flag has a value indicating “unselected station” as the unselected station physical channel list. , To the channel scan controller 25.
If the process proceeds from step S63 to step S25, the unselected station physical channel list includes all physical channels. If the process proceeds to step S25 without passing through step S63, it means that the physical channel was an "unselected station" before the processing of FIG. 11, that is, the channel was selected in the channel scan in the mesh area even once. Only physical channels that do not have are included in the unselected station physical channel list.

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

When the channel scan history determination unit 30 outputs the unselected station physical channel list, the channel scan control unit 25 starts the channel scan in response to this.
The channel scan is generally performed in the same procedure as that described in the first embodiment with reference to FIG. 7.
After selecting each physical channel by the channel scan, the channel scan control unit 25 rewrites the selected channel flag of the physical channel to “selected channel”. This process is performed in step S41 of FIG.

By repeating steps S33 to S41, when sequential selection of all physical channels is completed, it is considered that “channel scanning is completed”, and the date including the end point is set as the scan completion date, and the scan completion date 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 information shown. That is, the information indicating the new scan completion date is overwritten on the scan completion history information stored until then.
This overwrite processing can be performed in an additional step (not shown) inserted between step 41 and step S43 in FIG.

The channel scan periodically performed according to the channel scan history determination processing has been described above. Although the channel scan performed according to the change in the network configuration, the broadcast service configuration and the like has been described in the first embodiment, the channel scan according to the change in the network configuration, the broadcast service configuration and the like is similarly performed in the third embodiment. It can be carried out. In this case, channel scanning is performed for all physical channels even if the elapsed time from the scan completion date for each mesh area is not longer than the set period.
Even when a channel scan is performed according to a change 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 in the third embodiment, even after all the physical channels have been selected once or more by the channel scan in the mesh area to which the current position belongs, In the channel scan history determination process that is 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 has exceeded the set period, all physical channels are targeted. Channel scan is performed. Therefore, when the reception status changes, the status change 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 individually subject to channel scanning after the set period has elapsed, whereas in the second embodiment, In 3, the date when the channel scan is completed is stored for each mesh area, and a new channel scan is not executed until the set period elapses after the channel scan in the mesh area is completed. Therefore, the length of the period from when a channel is selected in one channel scan to when the channel is selected in the next channel scan varies depending on the physical channel.
However, since the reception status does not change frequently, it is considered that the influence from the difference in the period from the selection of one channel scan to the selection of the next channel scan is small.

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

Further, according to the digital broadcast receiving apparatus in the third embodiment, the information indicating the scan completion date in the channel scan history information is a certain reference date as in the channel selection execution date in the second embodiment. Information in which the total day starting from is expressed in 2 bytes is used. As a result, 2 bytes are used to represent the scan completion date for each mesh area. Since the selected channel 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, when the number of physical channels targeted for channel scanning is 40, 40 bits, that is, 5 bytes are required. A total of 7 bytes is required, including this and 2 bytes of information indicating the scan completion date. That is, in order to store the channel scan history information, a storage area of 7 bytes is required for each mesh.
This is 1/11 or less 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 device can be reduced.

Fourth Embodiment
In the third embodiment, the time when the scan is completed for each mesh area is expressed in units of days. In the fourth embodiment, the time when the scan is completed for each mesh area is expressed in units of months. As a result, 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 in FIG. 12 is generally the same as the channel scan history information in FIG. 10, except that the scan completion month is included instead of the scan completion date for each mesh area.

As the scan completion month, information in which the total month with a certain month as a reference (starting point) is represented by 1 byte is used. By allocating 1 byte (8 bits), it is possible to express which month of about 20 years.

As in the case of the third embodiment, since the channel selection completion 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, when the number of physical channels targeted for channel scanning is 40, 40 bits, that is, 5 bytes are required. A total of 6 bytes is required when this is combined with 1 byte of information indicating the scan completion month. That is, in order to store the channel scan history information, a storage area of 6 bytes is required for each mesh.

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 device can be reduced.

The fourth embodiment has been described above as a modified example of the third embodiment. The same modification can be applied to the second embodiment. That is, in the second embodiment, the tuning execution month may be recorded instead of the tuning execution date of each physical channel.

In the first, second, third, and fourth embodiments described above, the number of systems of the broadcast receiving means is two, but the number of systems may be three or more. In short, a plurality of broadcast receiving means are provided, the plurality of broadcast receiving means are all used for viewing the program in the first operation mode, and the plurality of broadcast receiving means of the plurality of broadcast receiving means are used in the second operation mode. It is sufficient that one broadcast receiving means is used for channel scanning and the other broadcast receiving means is used for viewing the program.

Embodiment 5.
FIG. 13 is a block diagram schematically showing the configuration of the digital broadcast receiving apparatus according to the fifth embodiment of the present invention.
The digital broadcast receiving apparatus of the first embodiment has two systems of broadcast receiving means, but the digital broadcast receiving apparatus of the fifth embodiment has only one system of broadcast receiving means. That is, the digital broadcast receiving apparatus 1b shown in FIG. 13 includes a broadcast receiving antenna 11, a tuner/demodulation unit 12, a demultiplexing unit 13, a video/audio decoding unit 14, and a graphics superimposing unit 15. The video output unit 16, the audio output unit 17, the operation input unit 18, the channel selection control unit 19, the channel scan control unit 25, the current position detection antenna 26, the current position detection unit 27, and the broadcast area map. It includes 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.

The second broadcast receiving antenna 21, the second tuner/demodulation 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 device 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.
In addition, among the constituent elements in FIG. 13, those having the same reference numerals as those in FIG. 1 have the same or similar functions.

The channel scan control unit 25 uses the tuner/demodulation unit 12 to perform a channel scan. 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 output the audio, and the video output unit 16 also outputs the video. I don't know.

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

The channel scan in the digital broadcast receiving apparatus according to the fifth embodiment is performed, for example, in the following cases. For example, if the selected physical channel cannot be received while the program is being viewed on the digital broadcast receiving apparatus, the mode may be automatically changed to the mode for performing the channel scan and the channel scan may be started. good. Alternatively, the user may manually operate the channel scan. Furthermore, when the digital broadcast receiving apparatus is not used for viewing a program (when it is connected to the power supply but the power switch is in the off state), the channel scan control unit 25 detects this and It is also possible to start scanning.

Further, since the digital broadcast receiving apparatus according to the fifth embodiment has one tuner/demodulation section and one demultiplexing section, 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 of the first embodiment, the same modifications can be applied to the second, third, and fourth embodiments.

In Embodiments 1 to 5 described above, a part of the digital broadcast receiving apparatus is realized by the processing circuit. The processing circuit may be dedicated hardware or a CPU that executes a program stored in the 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 above-described plurality of parts may be collectively realized by one 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 collectively realized by one processing circuit.

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

14 is a computer including a single CPU (shown by reference numeral 100) in which the processing circuit is a CPU, and the graphics superimposing unit 15, the tuning control unit 19, and the receiving unit 19 of the digital broadcast receiving apparatus 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 the function of is as follows: antennas 11, 21 and 26, first and second tuner/demodulators 12 and 22, first and second demultiplexers 13 and 23, video/audio It is shown together with the decoding unit 14, the video output unit 16, the audio output unit 17, and the operation input unit 18. 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 receiving device.

The computer 100 shown in FIG. 14 includes a CPU 101, a memory 102, and a bus 103 connecting these.
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, The antenna 26 is also connected.
A signal received by the antenna 26 is input to the CPU 101 via a receiver (not shown).

The memory 102 stores the program and also serves as the broadcast area map storage unit 29 and the channel scan history storage unit 39.

The CPU 101 operates according to a program stored in the memory 102, and has the graphics superimposing unit 15, the tuning 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 the processing, the CPU 101 includes the first and second tuner/demodulators 12 and 22, the first and second demultiplexers 13 and 23, the video/audio decoder 14, the video output unit 16, and the operation input unit 18. , And exchange signals, data, or information with the antenna 26.

The contents of the processing by the CPU 101 are the same as those described in the first, second, third, or fourth embodiment. The data generated in the process of processing is held in the memory 102.

FIG. 15 is a computer in which the above processing circuit is a CPU and includes a single CPU (denoted by reference numeral 100b), and the graphics superimposing unit 15, channel selection control unit 19, and channel of the digital broadcast receiving apparatus 1b 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. Of the configuration of the antennas 11 and 26, the first tuner/demodulation unit 12, the first demultiplexing unit 13, the video/audio decoding unit 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/demodulation unit 12, a first demultiplexing unit 13, a video/audio decoding unit 14, a video output unit 16, an audio output unit 17, and an operation input unit 18. The digital broadcast receiving device is configured by.

The computer 100 shown in FIG. 15 includes a CPU 101, a memory 102, and a bus 103 connecting these.
A first tuner/demodulation unit 12, a first demultiplexing unit 13, a video/audio decoding unit 14, a video output unit 16, an operation input unit 18, and an antenna 26 are connected to the bus 103.
A signal received by the antenna 26 is input to the CPU 101 via a receiver (not shown).

The memory 102 stores the program and also serves as the broadcast area map storage unit 29 and the channel scan history storage unit 39.

The CPU 101 operates according to a program stored in the memory 102, and has 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, and 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 causes the first tuner/demodulation unit 12, the first demultiplexing unit 13, the video/audio decoding unit 14, the video output unit 16, the operation input unit 18, and a signal, data, or the like with the antenna 26. Exchange information.

The content of the processing by the CPU 101 is the same as that described in the fifth embodiment. The data generated in the process 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 above digital broadcast receiving apparatus also forms part of the present invention. Further, a program for causing a computer to execute a part or all of the processing in the digital broadcast receiving apparatus, a part or all of the processing in the digital broadcast receiving method, and a computer-readable program recording the program. Recording media also form part of the invention.

11 First Broadcast Reception Antenna, 12 First Tuner/Demodulator, 13 First Demultiplexer, 14 Video/Audio Decoder, 15 Graphics Superimposing, 16 Video Output, 17 Audio Output, 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 unit, 28 broadcast area map generation unit, 29 broadcast area map storage unit, 30 channel scan history determination unit, 31 broadcast service list generation unit, 39 channel scan history storage unit, 40 broadcast signal reception Department.

Claims (10)

A digital broadcast receiving apparatus having at least one tuner/demodulation unit for selecting a physical channel and demodulating a broadcast signal of the selected physical channel,
A current position detector for detecting the current position of the digital broadcast receiving device,
A channel scan controller that performs a channel scan to determine whether each physical channel is receivable using the at least one tuner/demodulator,
A broadcast area map generator that generates information indicating a receivable area for each physical channel based on the result of the channel scan;
A broadcast service list generation unit that generates a service list indicating broadcast services receivable at the current position 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 a channel scan based on information about a mesh area to which the current position detected by the current position detection unit belongs, among the channel scan history information stored in the channel scan history storage unit. Decide the physical channel to tune in ,
The channel scan history information stored in the channel scan history storage unit is
When the channel scan in each mesh area has never been completed, it includes the information indicating that the channel scan has never been completed, and the channel scan in each mesh area has been completed once or more. In that case, within the mesh area, scan completion history information including information indicating the date or month when the channel scan was last completed,
Including tuning history information indicating whether or not each physical channel has been selected,
The tuning history information is
When the channel scan in each mesh area has never been completed, including the information indicating whether or not each physical channel has been selected by the channel scan in each mesh area,
When a channel scan in each mesh area has been completed once or more, it is characterized by including information indicating whether or not each physical channel is selected during execution of the channel scan in each mesh area. Digital broadcasting receiver. Referring to the channel scan history information stored in the channel scan history storage unit,
If the scan completion history information includes information indicating that the channel scan within the mesh area to which the current position detected by the current position detection unit belongs has never been completed, it means that the channel has been selected yet. Output the list of physical channels that do not exist as the unselected station physical channel list,
When the scan completion history information includes information indicating the date or month when the channel scan was last completed, and when the elapsed period since the last channel scan was completed is a preset period or more, all Further has a channel scan history determination unit that outputs the list of physical channels of
The digital broadcast receiving apparatus according to claim 1 , wherein the channel scan control unit performs a channel scan on physical channels included in the unselected station physical channel list. The channel scan control unit updates the channel scan history information on the mesh area to which the current position when the channel selection is performed when the channel selection is performed for each physical channel in the channel scan. the digital broadcast receiving apparatus according to claim 1 or 2. In the channel scan for each mesh area, when the channel selection for all the physical channels is completed, the channel scan control unit provides the information indicating the end date or month for the channel scan in the mesh area. The digital broadcast receiving apparatus according to claim 1 or 2 , wherein the channel scan history information is updated as new information indicating a finally completed date or month. The mesh area, in any one of claims 1, characterized in that one formed by separating a grid pattern by a line parallel broadcast reception target area parallel lines and latitude lines meridian 4 The described digital broadcast receiving device. The broadcast area map generator is an orthogonal coordinate system of the coordinates of the vertices of a polygon that approximates the coverage area, any one of claims 1 5, characterized in that generated as information representing the receivable area The digital broadcast receiving device according to. The at least one tuner/demodulator includes a plurality of tuners/demodulators,
The operation modes of the plurality of tuners/demodulation units are the first operation mode in which the plurality of tuners/demodulation units are all used for program viewing, or one tuner/demodulation unit of the plurality of tuners/demodulation units. The tuner/demodulator other than the one tuner/demodulator is used for channel scanning, and the tuner/demodulator further has a reception mode selector that switches to a second operation mode used for program viewing,
The channel scan control unit, to the reception mode switching unit when performing the channel scan, any one of claims 1 to 6, characterized by instructing the switching to the second mode of operation The digital broadcast receiving device according to. 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 receiving device,
Perform a channel scan to determine whether each physical channel can be received,
Generates information indicating the receivable area for each physical channel based on the result of the channel scan ,
Generating a service list showing broadcast services receivable at the current position based on the generated information indicating the receivable area,
The channel scan history information indicating the history of the channel scan is stored for each mesh area,
Of the channel scan history information, based on the information about the mesh area to which the current position belongs, determine the physical channel to be selected in the channel scan ,
The channel scan history information is
When the channel scan in each mesh area has never been completed, it includes the information indicating that the channel scan has never been completed, and the channel scan in each mesh area has been completed once or more. In that case, within the mesh area, scan completion history information including information indicating the date or month when the channel scan was last completed,
Includes tuning history information indicating whether each physical channel has been tuned,
The tuning history information is
When the channel scan in each mesh area has never been completed, including the information indicating whether or not each physical channel has been selected by the channel scan in each mesh area,
When a channel scan in each mesh area has been completed once or more, it is characterized by including information indicating whether or not each physical channel is selected during execution of the channel scan in each mesh area. Digital broadcasting reception method. A program for causing a computer to execute the processing in the digital broadcast receiving method according to claim 8 . A computer-readable recording medium in which the program according to claim 9 is recorded.

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