JP5697760B2 - Broadcast receiving apparatus and navigation apparatus - Google Patents

Description

  The present invention is equipped with a tuner for receiving broadcast waves of a program to be viewed and mounted on a moving body such as a vehicle, and a broadcast receiving apparatus including a background tuner for searching for a receivable broadcast station, and the same. The present invention relates to a navigation device.

  Some conventional broadcast receivers use a background tuner to perform broadcast station search and reception of data broadcasts such as traffic information in order within a certain time. In this broadcast receiving apparatus, when priority is given to ensuring that the broadcast station selected from the broadcast station list obtained by the broadcast station search can be properly received at the current position, that is, ensuring the real-time property of the so-called broadcast station list. Therefore, it is necessary to lengthen the time for searching for the broadcast station within a certain time, and accordingly, the time for receiving the data broadcast within a certain time is shortened. In this case, since the amount of data such as traffic information decreases, it becomes impossible to provide information useful for driving the vehicle.

  On the other hand, when priority is given to receiving data broadcasts, it is necessary to lengthen the time for receiving data broadcasts within a certain period of time. The interval at which the broadcast station list is updated becomes longer. As a result, the real-time property of the broadcast station list is likely to be impaired, and even if a broadcast station is selected from the broadcast station list, the vehicle may have already moved to a place where the broadcast station cannot be received.

  As a conventional technique for solving the above-described problems, there is a broadcast receiving apparatus disclosed in Patent Document 1, for example. In this apparatus, an area that can be received for each broadcasting station is created as a broadcasting area map and stored in a database, and a list of broadcasting stations that can be received at the current position is created by referring to the broadcasting area map.

JP 2011-61753 A

  The conventional broadcast receiving apparatus represented by Patent Document 1 does not consider the radio wave situation that changes every moment, and creates a broadcast station list based on a broadcast area map created in the past. If the broadcast station changes, the broadcast station that can be received at the current position may differ from the broadcast station in the broadcast station list.

  The present invention has been made to solve the above-described problems, and includes a broadcast receiving apparatus and a broadcast receiving apparatus that can appropriately perform a broadcast station search and data broadcast reception according to a radio wave condition at a current position. The object is to obtain a navigation device.

A broadcast receiving apparatus according to the present invention is mounted on a mobile unit, and includes a first tuner that receives broadcast waves from a broadcast station, and a search for a broadcast station that can be received by other than the broadcast station that the first tuner is receiving. In the broadcast receiving apparatus including the second tuner that receives the data broadcast between the searches, the current position calculation unit that calculates the current position, and the second tuner performs a search for the broadcasting station. A distance calculation unit that calculates the distance from the current position to the current position calculated by the current position calculation unit, and when the distance calculated by the distance calculation unit is equal to or greater than a predetermined threshold, immediately performs a search for a broadcast station, Alternatively, a decision is made to increase the search frequency of the broadcast station, and if the distance calculated by the distance calculation unit is less than a predetermined threshold, a search for the broadcast station is not performed or a decision to reduce the search frequency of the broadcast station is made. A Cormorant search frequency determining unit, in search frequency determined by the search frequency determining section, and a search control section for controlling to perform the search of the broadcast station by the second tuner, search frequency and search frequency determining section broadcasters A second storage unit that stores the position information for which the search frequency has been determined as history information, and the search frequency determination unit has a search frequency for history information corresponding to the current position read from the second storage unit being predetermined. When it is equal to or higher than the threshold value, a determination is made to increase the search frequency of the broadcasting station corresponding to the history information.

  According to the present invention, there is an effect that broadcast station search and data broadcast reception can be appropriately performed according to the radio wave condition at the current position.

It is a block diagram which shows the structure of the broadcast receiver which concerns on Embodiment 1 of this invention. It is a block diagram which shows the structure of the broadcast receiver which concerns on Embodiment 1, and a navigation apparatus provided with the same. It is a figure which shows the time allocation of the conventional broadcast station search and data broadcast reception. It is a figure which shows the broadcast station search and time allocation (condition 1) of data broadcasting reception which concern on Embodiment 1. FIG. It is a figure which shows the time allocation (condition 2) of the broadcast station search which concerns on Embodiment 1, and data broadcasting reception. It is a figure which shows the broadcast station search and time allocation (condition 4) of data broadcasting reception which concern on Embodiment 1. FIG. 6 is a flowchart showing an operation (condition 7) of the broadcast receiving apparatus according to the first embodiment.

Hereinafter, in order to describe the present invention in more detail, modes for carrying out the present invention will be described with reference to the accompanying drawings.
Embodiment 1 FIG.
FIG. 1 is a block diagram showing a configuration of a broadcast receiving apparatus according to Embodiment 1 of the present invention, and shows a case where the present invention is applied to a radio receiver mounted on a mobile body (for example, a vehicle). In FIG. 1, a broadcast receiving apparatus 1 according to Embodiment 1 includes a main tuner 2a, a background tuner unit 2b, an operation unit 3, an arithmetic control unit 4, a display unit 5, a broadcast station search result storage unit 6, a broadcast station search. A frequency storage unit 7 and a positioning unit 8 are provided.

  The main tuner 2a is a tuner that receives a broadcast from a broadcast station selected by the user. The background tuner unit 2b searches for a broadcast station that can be received at the current position, traffic information (for example, RDS-TMC; Radio Data System-Traffic Message Channel, VICS (registered trademark); This is a tuner unit that receives data broadcasts such as broadcasts and traffic information broadcast on HD (High Definition) radio in the United States.

The operation unit 3 is an operation unit that receives an operation input from the outside, and may be a software key or a button displayed on the screen of the display unit 5 that performs input using a touch panel in addition to hardware such as a keyboard and buttons. . For example, the user refers to the broadcast station list displayed on the display unit 5, selects a broadcast station of a program to be listened to, and designates the broadcast station using the operation unit 3.
The arithmetic control unit 4 is a control unit that performs arithmetic processing such as channel selection, broadcasting station search, and display processing. The display unit 5 is a display device such as a liquid crystal display, a plasma display, or an organic EL display.

  The broadcast station search result storage unit 6 is a storage unit that stores the broadcast station list created in the broadcast station list creation unit 43 in association with the current position. That is, in the broadcast station search result storage unit 6, data including a broadcast station list and position information on which the broadcast station search is performed is accumulated in time series for each band (reception frequency band) on which the broadcast station search is performed. The

  The broadcast station search frequency storage unit 7 is a storage unit that stores the broadcast station search frequency determined by the search frequency determination unit 45 in association with the current position. Similarly, the broadcast station search frequency storage unit 7 accumulates data including a search frequency and position information that determines the search frequency for each band in which the broadcast station search is performed. The broadcast station search frequency storage unit 7 may store a search frequency coefficient A (see condition 1 described later) that defines the search frequency.

  The positioning unit 8 is a unit that measures the current position, and specifies position information from satellite position and time information included in a GPS signal received from a GPS satellite, for example. This position information is output from the positioning unit 8 to the current position calculation unit 47.

The arithmetic control unit 4 includes a main tuner reception frequency setting unit 40, a background tuner reception frequency setting unit 41, a data reception unit 42, a broadcast station list creation unit 43, a search control unit 44, and a search frequency determination unit 45 as functional blocks. A distance calculation unit 46, a current position calculation unit 47, and a display control unit 48.
The main tuner reception frequency setting unit 40 inputs a signal (channel information or the like) indicating a broadcast station designated by the user using the operation unit 3, and sets the reception frequency of the broadcast station in the main tuner 2a based on the signal. To do.
When receiving a request from the data receiving unit 42 or the search control unit 44, the background tuner receiving frequency setting unit 41 sequentially sets the receiving frequency of each band for scanning a receivable broadcasting station in the background tuner unit 2b. The background tuner unit 2b starts a broadcast station search.

The data receiving unit 42 receives broadcast data such as traffic information received by the background tuner unit 2 b and outputs display information included in the broadcast data to the display control unit 48.
The broadcast station list creation unit 43 inputs the scan result of each band by the background tuner unit 2b, and creates a broadcast station list of broadcast stations that can be received at the current position. In the broadcast station list, broadcast stations that can be received at the current position are listed. As information on each broadcast station, the name of the broadcast station, the reception frequency, the reception electric field level of the reception frequency at the time of search, and the like are registered. The
The broadcast station list creation unit 43 outputs the created broadcast station list to the display control unit 48 and further stores the broadcast station list in the broadcast station search result storage unit 6 in association with the current position input from the current position calculation unit 47.

The search control unit 44 is a control unit that controls the background tuner reception frequency setting unit 41 at the broadcast station search frequency determined by the search frequency determination unit 45 and causes the background tuner unit 2b to perform a broadcast station search. is there.
The search frequency determination unit 45 determines a search frequency for performing a broadcast station search based on the stored contents of the distance calculation unit 46, the current position calculation unit 47, and the broadcast station search result storage unit 6. Here, the search frequency means the number of times (frequency) that the broadcast station search is performed in a predetermined period.
For example, the time until the broadcast station list is created by one broadcast station search of FM broadcast is 4 seconds, and the time until the broadcast station list is created by one broadcast station search of AM (MW) broadcast is 14 seconds, 14 seconds for the broadcast station list to be created by one broadcast station search for SW broadcast, and 14 seconds for the broadcast station list to be created for one broadcast station search for LW broadcast When performing a broadcast station search in the order of FM, AM, SW, LW, and data broadcast reception (for example, reception of traffic information from FM broadcast waves), in 60 seconds (predetermined period), Broadcast station search and data broadcast reception are performed once, and the timetable for data broadcast reception is 14 seconds.
In other words, FM broadcast station search is performed at 56 second intervals, AM broadcast station search is performed at 46 second intervals, SW broadcast station search is performed at 46 second intervals, and LW broadcast station. The search is performed at intervals of 46 seconds, and the data broadcast reception is performed at intervals of 46 seconds.
The search frequency determination unit 45 determines the search frequency according to the current radio wave condition by changing the time interval of the broadcast station search according to various conditions indicating the radio wave condition at the current position.

The distance calculation unit 46 is a calculation unit that calculates the distance from the position where the previous broadcast station search was performed to the current position. The current position calculation unit 47 calculates the current position of the host vehicle based on the position information acquired from the positioning unit 8.
The display control unit 48 is a control unit that controls display processing in the display unit 5. For example, the display control unit 48 inputs the broadcast station list from the broadcast station list creation unit 43, and in addition to the broadcast station name currently received by the main tuner 2a, the current reception scanned in the background is received. Possible broadcast station names are displayed on the display unit 5.
The display control unit 48 updates the currently receivable broadcast station name displayed on the display unit 5 every time a broadcast station search is performed. When the vehicle arrives in a tunnel where the radio wave condition is poor and there are no receivable broadcasting stations, only the name of the currently receiving broadcasting station is displayed.

The broadcast receiving apparatus according to Embodiment 1 may also use the positioning unit 8 or the like as a navigation apparatus.
FIG. 2 is a block diagram illustrating a configuration of the broadcast receiving apparatus according to Embodiment 1 and a navigation apparatus including the broadcast receiving apparatus. The navigation device 9 shown in FIG. 2 is a navigation device for a moving body mounted on a moving body (for example, a vehicle), and the positioning unit 8 and the current position calculation unit 47 are also used as the broadcast receiving device 1. The navigation processing unit 10 executes navigation processing such as route search, route guidance, and map display based on the vehicle position calculated by the current position calculation unit 47 and the map data in the map database (map DB) 11.
The map DB 11 is a database in which map data used by the navigation processing unit 10 is registered. Map data includes topographic map data, residential map data, road networks, and the like. Image information for route guidance and map display is sent from the navigation processing unit 10 to the display control unit 48 and displayed on the display unit 5.
Further, when the background tuner unit 2 b receives traffic information, the navigation processing unit 10 may display a map based on the traffic information input via the data receiving unit 42. For example, when traffic jam information is acquired, the driver can select a route avoiding the traffic jam location by indicating the traffic jam location on the map display around the vehicle.

Next, the operation will be described.
First, conventional broadcast station search and data broadcast reception time allocation will be described with reference to FIG. FIG. 3 shows time allocation for AM broadcast station search, FM broadcast station search, and data broadcast reception. Here, the broadcasting station search for AM broadcasting is carried out at a constant time interval T _AM, broadcast station search of FM broadcasting is carried out at a constant time interval T _FM broadcast of the broadcast station search and FM broadcasting AM broadcast Data broadcasting is being received at the time when station search is not available.
That is, the broadcast station list of AM broadcasting is updated every time T _AM, broadcast station list of FM broadcast is updated every time T _FM.

The broadcast wave of AM broadcast reaches far away with less attenuation of radio wave than FM broadcast. For this reason, when the vehicle is moving at a low speed, there is a high possibility that even if the broadcast station list is updated every time T _AM (for example, 1 minute), there is no change from the previous search content.
On the other hand, since the reception status of FM broadcasting is more likely to change depending on the location compared to AM broadcasting, if the vehicle moves at a high speed and the current location moves away from the location where the previous broadcasting station search was performed, the broadcasting station list Real-time performance is easily lost. If a broadcast station search and data broadcast reception are performed in a predetermined timetable as in the past, there is a possibility that the vehicle has already moved to a place where the broadcast station cannot be received.

  Therefore, in the broadcast receiving apparatus 1 according to the present invention, the broadcast station search frequency is changed according to the current position of the own vehicle and the radio wave condition, so that the broadcast station with a very high real-time property according to the radio wave condition of the current position is obtained. Even if the list is updated and the search frequency is changed, the received data amount of broadcast data such as traffic information (for example, traffic information broadcast on RDS-TMC, VICS broadcasting, US HD radio, etc.) is reduced unnecessarily. Is prevented. In order to perform broadcast station search and data broadcast reception at appropriate timing, the present invention proposes the following conditions.

(A) Condition 1
When the distance between the position where the previous broadcast station search was performed and the current position is greater than or equal to a predetermined distance, the broadcast station search is immediately performed, or the search frequency is increased from the current frequency. By this processing, a broadcast station search is performed at an appropriate timing, and a broadcast station list corresponding to the current radio wave condition is obtained.
If the position between the previous broadcast station search and the current position is less than a predetermined distance, the broadcast station search is not performed, or the search frequency is lowered from the current frequency. By this processing, the time required for unnecessary broadcast station search can be reduced, and the time for receiving data broadcasts such as traffic information can be increased. Therefore, the user can obtain traffic information such as traffic jam information without omission.

The distance calculation unit 46 inputs the current position information calculated by the current position calculation unit 47, reads out the position information of the place where the previous broadcast station search was performed from the broadcast station search result storage unit 6, and the previous broadcast Calculate the distance from the station search position to the current position.
The search frequency determination unit 45 compares the distance information calculated by the distance calculation unit 46 with a predetermined distance (threshold), and determines whether or not the distance from the previous broadcast station search position to the current position is equal to or greater than the predetermined distance. Determine.

  When the distance from the previous broadcast station search position to the current position is equal to or greater than a predetermined distance, the search frequency determining unit 45 immediately performs a broadcast station search or increases the search frequency above the current frequency. I do. Also, if the distance from the previous broadcast station search position to the current position is less than a predetermined distance, the broadcast station search is not performed, or the search frequency is lowered from the current frequency.

For example, for AM broadcast station search and FM broadcast station search, a search frequency reference value is determined in advance, and the search frequency is changed by changing the value of the search frequency coefficient A integrated to this reference value. To do.
If the search frequency coefficient A after adding a predetermined value to the search frequency coefficient A is equal to or greater than a predetermined threshold X when the distance from the previous broadcast station search position to the current position is equal to or greater than the predetermined distance, immediately Conduct a broadcast station search.
Further, although less than the threshold value X, if the threshold value X is smaller than the threshold value Y or more, the search frequency determining section 45, shorten the time interval T _AM or T _FM broadcast station search. As a result, the search frequency can be increased from the previous frequency.
When the distance from the previous broadcast station search position to the current position is less than the predetermined distance, the broadcast station search is performed if the search frequency coefficient A after subtracting the predetermined value from the search frequency coefficient A is equal to or greater than the predetermined threshold X. Do not implement.
Further, although less than the threshold value X, if the threshold value Y is smaller than the threshold value Z or more, the search frequency determining section 45 extends the time interval T _AM or T _FM broadcast station search. Thereby, the search frequency can be made lower than the previous frequency.

FIG. 4 is a diagram showing time allocation (condition 1) for broadcast station search and data broadcast reception according to the first embodiment. Example shown in FIG. 4 was performed the station search AM broadcast at fixed time intervals T _AM, carried the station search FM broadcast at fixed time intervals T _FM, broadcast station search and FM broadcasting AM broadcast It shows a case where data broadcast reception is carried out in the time when the broadcast station search is free.
When the own vehicle is stationary and there is no movement from the place where the previous broadcast station search was performed, or when the distance from the previous broadcast station search position to the current position is less than a predetermined distance, the search frequency determination unit 45 The search control unit 44 is instructed to perform a broadcast station search at a normal search frequency. The search control unit 44 performs AM broadcast station search and FM broadcast station search after the times T _AM and T _FM have elapsed in the broadcast station search timer according to the instruction of the search frequency determination unit 45.

On the other hand, if the distance from the previous broadcast station search position to the current position is equal to or greater than the predetermined distance before the vehicle moves at high speed and the FM broadcast station search timer time T _FM elapses, The search frequency determination unit 45 instructs the search control unit 44 to perform a broadcast station search at that time. As a result, the search control unit 44 performs FM broadcast station search before the time T _FM elapses in the broadcast station search timer, as shown in FIG.

(B) Condition 2
Compare the broadcast station search results (broadcast station list) before and after the time series, and change the content of the broadcast station search results (the number of broadcast stations listed in the broadcast station list and the electric field level at the reception frequency of each broadcast station) Is greater than or equal to a predetermined threshold value, it is determined that the vehicle is in a state in which the radio wave condition is likely to fluctuate (region, vehicle speed), and the search frequency of the broadcasting station is increased. By this processing, the broadcast station list is frequently updated when the radio wave condition is likely to fluctuate, and a broadcast station list corresponding to the current radio wave condition is obtained.
If the amount of change in the content of the broadcast station search result is less than a predetermined threshold, it is determined that the vehicle is in a stable radio wave condition (region with few obstacles, stopped state), and the search frequency of the broadcast station Lower. By this processing, unnecessary updating of the broadcast station list under a condition where the radio wave condition is stable can be avoided, and the time for receiving data broadcasts such as traffic information can be increased. Therefore, the user can obtain traffic information such as traffic jam information without omission.

When a broadcast station search is performed under the control of the search control unit 44, the broadcast station list creation unit 43 stores the broadcast station search result storage unit 6 in association with the current position input from the current position calculation unit 47. After that, the search frequency determination unit 45 reads out the broadcast station search results before and after the time series from the broadcast station search result storage unit 6, compares the broadcast station search results for the previous time and the previous time, and searches for the broadcast station search. It is determined whether the amount of change in the content of the result is a predetermined threshold value or more.
Here, when the amount of change in the content of the broadcast station search result is equal to or greater than a predetermined threshold, the search frequency determination unit 45 performs a process of raising the search frequency from the current frequency. Also, if the change amount of the content of the broadcast station search result is less than a predetermined threshold value, a process for lowering the search frequency from the current frequency is performed. As in the case of condition 1 above, the search frequency may be changed by changing the value of the search frequency coefficient A.

FIG. 5 is a diagram showing time allocation (condition 2) for broadcast station search and data broadcast reception according to the first embodiment. Example shown in FIG. 5 was performed the station search AM broadcast at fixed time intervals T _AM, carried the station search FM broadcast at fixed time intervals T _FM, broadcast station search and FM broadcasting AM broadcast It shows a case where data broadcast reception is carried out in the time when the broadcast station search is free.
In FIG. 5, at the timing shown in (3) before the time T _AM elapses, the search frequency determination unit 45 starts a sequence for determining the broadcast station search frequency of AM broadcast, and stores the broadcast station search result. The result of the broadcast station search of AM broadcast performed at the timings (1) and (2) read from the unit 6 is compared.
When the change amount of the broadcast station search result is equal to or greater than a predetermined threshold, the search frequency determination unit 45 shortens the broadcast station search time interval T _AM and sets a new time interval T ′ _AM (T ′ _AM <T _AM ) Instruct the search control unit 44 to perform a broadcast station search.
As a result, the search control unit 44 performs a broadcast station search for AM broadcasts after (4) every time the time interval T ′ _AM elapses.

(C) Condition 3
Broadcast station search frequency is determined for each band. Since the broadcast station search time and radio wave propagation loss are different for each band such as AM and FM, the broadcast station search corresponding to the radio wave condition of each band is performed by determining the broadcast station search frequency for each band. be able to.
For example, in the AM broadcast with a low frequency, the radio wave of the broadcast wave reaches far compared with the FM broadcast. Therefore, the frequency of the broadcast station search to be performed within the same period is set lower than that in the FM broadcast. Also, in FM broadcasting with a high frequency, the radio wave condition varies greatly depending on the location, so that the search frequency of the broadcasting station is set high.
By this processing, the broadcast station list can be updated at an appropriate timing according to the radio wave situation assumed in the characteristics of each band, and time can be allocated to data broadcast reception without impairing the real-time property of the broadcast station list.

  The search frequency determining unit 45 performs processing according to the condition 1 and the condition 2 for each band, and determines the search frequency of each band. For example, as shown in FIG. 5, a sequence for determining the broadcast station search frequency for AM broadcast and FM broadcast is performed, and the search frequency is determined for AM broadcast and FM broadcast. The search control unit 44 performs a broadcast station search for each band at the search frequency determined by the search frequency determination unit 45. The broadcast station search result storage unit 6 stores a broadcast station list for each band, and the broadcast station search frequency storage unit 7 stores the search frequency of the broadcast station for each band.

(D) Condition 4
When the vehicle enters a place with poor signal conditions, such as a tunnel or underground parking lot, or when the vehicle leaves the place, the signal conditions change rapidly, so the content of the existing broadcast station list is actually There is a high possibility that it is not in line with the radio wave conditions.
Therefore, in condition 4, if there is a band for which a broadcast station search has been started, each band other than this band (for example, FM broadcast other than AM, SW, LW if a broadcast station search for AM broadcast has been started) or If there is no band that has started the broadcast station search (when data broadcasting is received), the process of condition 2 is performed for all bands, and the contents of the broadcast station search result that goes back and forth in time series in any of these bands When the amount of change is equal to or greater than a predetermined threshold, it is determined that the radio wave condition around the vehicle is abruptly changed and the contents of the broadcast station list are likely to fluctuate, and there is a change greater than the threshold. In addition to the band, for other bands, the broadcast station search is performed immediately, or the frequency of the broadcast station search is increased from the current level.
By doing in this way, even if the radio wave condition suddenly changes, it is possible to update to a broadcast station list having contents in accordance with the actual radio wave condition. Note that the predetermined threshold regarding the amount of change in the content of the broadcast station search result is determined according to the characteristics of each band, and may be different for each band.

If there is a band for which a broadcast station search has been started by the search control unit 44, the search frequency determination unit 45 is for a band other than this band, or for all bands if there is no band for which a broadcast station search has been started. The broadcast station search result (the number of broadcast stations and the electric field level of each frequency) is read from the broadcast station search result storage unit 6 and the broadcast station search result is compared with the previous and previous broadcast station search results. It is determined whether or not the amount of change in the content is equal to or greater than a predetermined threshold value.
At this time, if there is at least one band whose content change in the broadcast station search result is equal to or greater than a predetermined threshold, the search frequency determination unit 45 also applies to other bands in addition to the band that has changed above the threshold. A broadcast station search is performed immediately, or a process for increasing the search frequency from the current frequency is performed. As in the case of condition 1 above, the search frequency may be changed by changing the value of the search frequency coefficient A.

FIG. 6 is a diagram showing time allocation (condition 4) for broadcast station search and data broadcast reception according to the first embodiment. Example shown in FIG. 6 was performed the station search AM broadcast at fixed time intervals T _AM, carried the station search FM broadcast at fixed time intervals T _FM, broadcast station search and FM broadcasting AM broadcast It shows a case where data broadcast reception is carried out in the time when the broadcast station search is free.
When the search control unit 44 starts a broadcast station search for AM broadcasting at the timing (3), the search frequency determination unit 45 performs the previous (1) and (2) for FM broadcasting that is a band other than AM broadcasting. The broadcast station search result executed at the timing is read from the broadcast station search result storage unit 6 and the amount of change in the content is compared.
Here, if the amount of change in the broadcast station search result is equal to or greater than a predetermined threshold, the search frequency determination unit 45 determines that the radio wave condition around the vehicle has suddenly decreased, and the FM broadcast station search time. A new timer time T ′ _FM (T ′ _FM <T _FM ) that shortens the interval T _FM is determined, and a new time interval T ′ _AM (T ′ _AM <T T _AM ) is determined, and the search control unit 44 is instructed to perform a broadcast station search for AM and FM in synchronization with the determined time interval.
Thereby, as shown in FIG. 6, the search control unit 44 performs a broadcast station search for FM broadcasts after the timing of (2) in which the comparison is performed, every time the timer time T ′ _FM elapses, 3) A broadcast station search for subsequent AM broadcasts is performed each time the time interval T ′ _AM elapses.

(E) Condition 5
When priority is given to broadcast data to be received by data broadcasting and data with high priority is received, the search frequency of the broadcast station search is lowered. Thereby, a lot of time can be allocated to reception of broadcast data with high priority, and traffic information and the like can be appropriately provided to the user. For example, when it is necessary to receive traffic information (RDS-TMC) for two countries near the border, or when the user requests data content being broadcast, the priority of these broadcast data is set to a predetermined threshold or higher. Reduce the frequency of broadcast station searches.

  Condition 5 is effective when the traffic information is presented on the map display by the navigation processing unit 10. For example, when receiving traffic information (congestion information) included in FM broadcasting, it is assumed that FM Osaka is broadcasting traffic information for the entire Osaka area, and FM Kobe is broadcasting traffic information for the entire Kobe area. Therefore, if your vehicle is in Osaka and your destination is Kobe, you will need to receive traffic information from two FM broadcast stations in Osaka and Kobe to find an appropriate route that avoids traffic. There is. Therefore, by reducing the frequency of the broadcast station search and assigning the time spent for the broadcast station search to the data broadcast reception, it is possible to appropriately acquire the traffic information necessary for the route search.

  For example, the data receiving unit 42 determines the priority of the broadcast data received by the background tuner unit 2b when the user requests further reception of the broadcast data using the operation unit 3. The search frequency determining unit 45 is notified of this fact. When notified from the data receiving unit 42 that the priority of broadcast data is equal to or higher than a predetermined threshold, the search frequency determining unit 45 performs a process of reducing the frequency of broadcast station search for each band to be performed thereafter. The search control unit 44 performs a broadcast station search for each band at the search frequency determined by the search frequency determination unit 45. As a result, the background tuner unit 2b receives broadcast data requested by the user between broadcast station searches with reduced frequency.

(F) Condition 6
The search frequency of the broadcasting station is stored as history information in association with the determined position information, and the history information corresponding to the position information within a predetermined range including the current vehicle position is determined in the past. If the search frequency is equal to or higher than a predetermined threshold, processing for increasing the current broadcast station search frequency is performed. By doing so, it is possible to immediately determine whether or not to increase the frequency of searching for the broadcast station when the location where the vehicle has traveled in the past is reached again, and the update to the broadcast station list corresponding to the current radio wave condition is possible. It becomes possible.
In addition, as the predetermined range including the current vehicle position, a circular area having a radius with a predetermined distance from the current position may be considered, and the predetermined distance is a radio wave condition equivalent to the current position. Estimated distance is set. Further, this distance may be appropriately set by the user using the operation unit 3.

The search frequency determination unit 45 searches the broadcast station search frequency storage unit 7 for data corresponding to position information within a predetermined range including the current position calculated by the current position calculation unit 47, and the search frequency of the search result is a predetermined frequency. It is determined whether or not the threshold value is exceeded.
For example, when the search frequency coefficient A is stored as the search frequency, the history information of the search frequency coefficient A corresponding to position information within a predetermined range including the current position is compared with a predetermined threshold value. At this time, if the search frequency coefficient A is equal to or greater than a predetermined threshold value, the search frequency determining unit 45 increases the search frequency by adding a predetermined value to the current search frequency coefficient A.
It is possible to quickly update the broadcast station list with a high real-time property in a place where radio wave conditions that have traveled in the past are likely to fluctuate.

(G) Condition 7
By implementing the conditions 1 to 6 in combination, the broadcast station list can be updated at an appropriate timing according to the radio wave situation, and time can be allocated to data broadcast reception without impairing the real-time property of the broadcast station list.
FIG. 7 is a flowchart showing the operation of the broadcast receiving apparatus according to Embodiment 1, and shows the flow of processing according to condition 7.
First, the search frequency determination unit 45 refers to a broadcast station search timer each time a broadcast station search is performed, and starts a predetermined time interval (timer) for performing the broadcast station search from the time when the previous broadcast station search is performed. It is determined whether or not (time) has elapsed (step ST1).
Here, if a predetermined time interval has elapsed in the broadcast station search timer (step ST1; YES), the search frequency determination unit 45 adds a predetermined value α to the search frequency coefficient A indicating the search frequency of the band. Thus, the search frequency is increased (step ST2).

If the process of step ST2 is completed or if a predetermined time interval has not elapsed by the timer (step ST1; NO), the search frequency determining unit 45 uses the distance information calculated by the distance calculating unit 46 as the predetermined distance. In comparison with the above, it is determined whether or not the distance from the position where the previous broadcast station search was performed to the current position is equal to or greater than a predetermined distance (step ST3).
At this time, if the distance from the previous broadcast station search position to the current position is equal to or greater than the predetermined distance (step ST3; YES), the search frequency determining unit 45 adds the predetermined value β to the search frequency coefficient A of the band. Thus, the search frequency is increased (step ST4).

When the process of step ST4 is completed, or when the distance from the previous broadcast station search position to the current position is less than a predetermined distance (step ST1; NO), the search frequency determination unit 45 sends broadcast data from the data reception unit 42. It is determined whether or not it is notified that the priority of receiving broadcast data is equal to or higher than a predetermined threshold (step ST5).
At this time, if the priority for receiving broadcast data is high (step ST5; YES), the search frequency determining unit 45 subtracts a predetermined value γ from the search frequency coefficient A of each band to lower the search frequency (step). ST6).

When the process of step ST6 is completed, or when the priority for receiving broadcast data is less than a predetermined threshold (step ST5; NO), the search frequency determination unit 45 displays the broadcast station search results before and after time series. The data is read from the broadcast station search result storage unit 6 for each band, the previous and previous broadcast station search results are compared, and it is determined whether or not the amount of change in the content of the broadcast station search result is equal to or greater than a predetermined threshold. (Step ST7). Here, a case will be described in which the amount of change in the number of broadcast stations listed in the broadcast station list is compared among the contents of the broadcast station search results.
When the number of broadcast stations in the previous and previous broadcast station search results fluctuates by more than a predetermined threshold (step ST7; YES), the search frequency determining unit 45 sets a predetermined value δ to the search frequency coefficient A of each band. To increase the search frequency (step ST8).

When the process of step ST8 is completed, or when the number of broadcast stations in the broadcast station search result for the previous and previous broadcasts is less than a predetermined threshold (step ST7; NO), the search frequency determining unit 45 The broadcast station search frequency storage unit 7 is searched with position information within a predetermined range including the current position calculated by the current position calculation unit 47, and history information corresponding to the position information within the predetermined range is broadcast station search frequency. It is determined whether or not it exists in the storage unit 7 (step ST9).
Here, when there is a search frequency history corresponding to position information within a predetermined range including the current position (step ST9; YES), the search frequency determination unit 45 reads the search frequency history from the broadcast station search frequency storage unit 7. The search frequency coefficient A is read out, and it is determined whether or not the search frequency coefficient A is equal to or greater than a predetermined threshold (step ST10).
When the search frequency coefficient A of the search frequency history is equal to or greater than a predetermined threshold (step ST10; YES), the search frequency determining unit 45 sets a predetermined value ε to the current search frequency coefficient A of the band corresponding to the search frequency history. Addition increases the search frequency (step ST11).

When the process of step ST11 is completed or the search frequency coefficient A of the search frequency history is less than a predetermined threshold (step ST10; NO), or corresponds to position information within a predetermined range including the current position When there is no search frequency history to be performed (step ST9; NO), the search frequency determination unit 45 determines whether or not the search frequency coefficient A for each band is equal to or greater than the threshold value X (step ST12).
For bands whose search frequency coefficient A is equal to or greater than the threshold value X (step ST12; YES), the search frequency determining unit 45 instructs the search control unit 44 to immediately perform a broadcast station search. Thereby, search control unit 44 immediately performs a broadcast station search for the band instructed from search frequency determination unit 45 (step ST13). Thereafter, the search frequency determination unit 45 returns to step ST1 and repeats the above-described processing.

  When the search frequency coefficient A is less than the threshold value X (step ST12; NO), the search frequency determination unit 45 determines whether or not the search frequency coefficient A is equal to or greater than the threshold value Y (X> Y) (step ST14). ). When the search frequency coefficient A is greater than or equal to the threshold Y (step ST14; YES), the search frequency determination unit 45 shortens the time interval (timer time) for performing the broadcast station search for the band and notifies the search control unit 44 of it. (Step ST15). This increases the frequency of broadcast station search for the band. Thereafter, the search frequency determination unit 45 returns to step ST1 and repeats the above-described processing.

  When the search frequency coefficient A is less than the threshold Y (step ST14; NO), the search frequency determination unit 45 determines whether or not the search frequency coefficient A is equal to or greater than the threshold Z (Y> Z) (step ST16). ). Here, when the search frequency coefficient A is equal to or greater than the threshold value Z (step ST16; YES), the search frequency determination unit 45 extends the time interval (timer time) for performing the broadcast station search of the band, and performs a search control unit. 44 is notified (step ST17). As a result, the frequency of the broadcast station search for the band decreases. Thereafter, the search frequency determination unit 45 returns to step ST1 and repeats the above-described processing.

As described above, according to the first embodiment, the current position calculation unit 47 calculates the current position from the current position calculation unit 47 that calculates the current position and the position where the background tuner unit 2b searches for the broadcasting station. The distance calculation unit 46 for calculating the distance to the current position, and when the distance calculated by the distance calculation unit 46 is equal to or greater than a predetermined threshold, the broadcast station search is immediately performed, or the broadcast station search frequency is set to When the distance calculated by the distance calculation unit 46 is less than a predetermined threshold, the search frequency determination unit 45 that does not perform a search for the broadcast station or determines to decrease the search frequency of the broadcast station And a search control unit 44 for controlling the background tuner unit 2b to search for a broadcast station at the search frequency determined by the search frequency determination unit 45.
In this way, when the distance from the previous broadcast station search position to the current position is equal to or greater than a predetermined distance, the broadcast station search is immediately performed, or the search frequency is increased from the current frequency, A broadcast station search is performed at an appropriate timing, and a list of broadcast stations corresponding to the current radio wave condition is obtained.
In addition, if the distance from the previous broadcast station search position to the current position is less than the predetermined distance, unnecessary broadcasts can be performed by not performing the broadcast station search or by performing a process of lowering the search frequency from the current frequency. The time required for station search can be reduced, and the time for receiving data broadcasts such as traffic information can be increased. Therefore, the user can obtain traffic information such as traffic jam information without omission.

Further, according to the first embodiment, the broadcast station search result storage unit 6 that stores the search result of the broadcast station performed by the background tuner unit 2b and the time series read from the broadcast station search result storage unit 6 When the fluctuation amount of the search result contents of the preceding and following broadcast stations is equal to or greater than a predetermined threshold, the broadcast station search frequency is determined to be increased. When the frequency is less than the threshold, the search frequency determining unit 45 for determining to decrease the search frequency of the broadcast station and the search frequency determined by the search frequency determining unit 44 perform the search for the broadcast station by the background tuner unit 2b. And a search control unit 44 for controlling. In this way, when the amount of change in the contents of the broadcast station search result is equal to or greater than a predetermined threshold and the vehicle is in a state where the radio wave condition is likely to fluctuate, the radio wave condition is increased by performing a process of increasing the broadcast station search frequency. The broadcast station list is frequently updated when the condition is likely to fluctuate, and a broadcast station list in accordance with the radio wave condition is obtained.
Also, if the amount of change in the contents of the broadcast station search results is less than a predetermined threshold and the vehicle is in a stable radio wave condition, the radio wave condition is stabilized by performing a process to reduce the search frequency of the broadcast station. Under such conditions, unnecessary updating of the broadcast station list is refrained, and the time for receiving data broadcasts such as traffic information can be increased. Therefore, the user can obtain traffic information such as traffic jam information without omission.

  Furthermore, according to the first embodiment, the search frequency determination unit 44 determines the search frequency for each band for which the background tuner unit 2b performs the search for the broadcast station, so that the broadcast according to the radio wave condition of each band. Station search can be performed.

  Further, according to the first embodiment, the broadcast station search result storage unit 6 stores the search result of the broadcast station for each band performed by the background tuner unit 2b, and the search frequency determination unit 45 It is determined for each band whether or not the fluctuation amount of the content of the search result of the broadcast station preceding and following the time series read from the search result storage unit 6 is equal to or greater than a predetermined threshold, and among the search results of the broadcast station for each band If there is a variation whose amount is greater than or equal to a predetermined threshold, a determination is made to increase the search frequency of broadcast stations in all bands. By doing in this way, even if the radio wave condition suddenly changes, it is possible to update to a broadcast station list having contents in accordance with the actual radio wave condition.

  Furthermore, according to the first embodiment, when the search frequency determination unit 45 prioritizes the reception of data broadcasting by the background tuner unit 2b, the search frequency determination unit 45 determines to lower the search frequency of the broadcast station. It is possible to allocate a lot of time for receiving high-frequency broadcast data, and to appropriately provide traffic information and the like to the user.

  Furthermore, according to the first embodiment, the broadcast station search frequency and search frequency determination unit 45 includes the broadcast station search frequency storage unit 7 that stores the position information at which the search frequency is determined as history information, and the search frequency determination When the search frequency of the history information corresponding to the current position read from the broadcast station search frequency storage unit 7 is equal to or higher than a predetermined threshold, the unit 45 determines to increase the search frequency of the broadcast station corresponding to the history information. . By doing so, it is possible to immediately determine whether or not to increase the frequency of searching for the broadcasting station when the location where the vehicle has traveled in the past is reached again, and updating to the broadcasting station list according to the current radio wave condition is possible. It becomes possible.

  Furthermore, according to the first embodiment, since the navigation device 9 includes the broadcast receiving device 1 described above, unnecessary broadcast station searches are reduced according to radio wave conditions, and accordingly, reception of broadcast data such as traffic information is received. Since the amount of data can be secured, navigation processing using traffic information can be performed accurately.

  Moreover, although the case where the navigation apparatus according to the present invention is applied to an in-vehicle navigation apparatus has been described in the first embodiment, the present invention is not limited to this. For example, you may apply not only to vehicle-mounted but to a mobile telephone terminal or a portable information terminal (PDA; Personal Digital Assistance). Moreover, you may apply to PND (Portable Navigation Device) etc. which a person carries and uses in moving bodies, such as a vehicle, a railroad, a ship, or an aircraft.

  In the present invention, any component of the embodiment can be modified or any component of the embodiment can be omitted within the scope of the invention.

  Since the broadcast receiving apparatus according to the present invention can appropriately perform a broadcast station search and data broadcast reception according to the radio wave condition at the current position, the in-vehicle radio in which the radio wave condition changes every moment as the vehicle travels. Suitable for receivers.

  DESCRIPTION OF SYMBOLS 1 Broadcast receiver, 2a Main tuner, 2b Background tuner part, 3 Operation part, 4 Calculation control part, 5 Display part, 6 Broadcast station search result storage part, 7 Broadcast station search frequency storage part, 8 Positioning unit, 9 Navigation Device, 10 navigation processing unit, 11 map database (map DB), 40 main tuner reception frequency setting unit, 41 background tuner reception frequency setting unit, 42 data reception unit, 43 broadcast station list creation unit, 44 search control unit, 45 Search frequency determination unit, 46 distance calculation unit, 47 current position calculation unit, 48 display control unit.

Claims (6)

A search is performed for a first tuner that is mounted on a mobile body and receives broadcast waves from a broadcast station, and a broadcast station that can be received by other than the broadcast station that the first tuner is receiving. A broadcast receiving device comprising a second tuner for receiving a data broadcast;
A current position calculator for calculating the current position;
A distance calculation unit for calculating a distance from a position where the search of the broadcasting station is performed in the second tuner to the current position calculated by the current position calculation unit;
When the distance calculated by the distance calculation unit is equal to or greater than a predetermined threshold, the broadcast station search is immediately performed, or the broadcast station search frequency is determined to be increased, and the distance calculated by the distance calculation unit is predetermined. A search frequency determining unit that does not perform a search for a broadcast station or determines to reduce the search frequency of a broadcast station,
A search control unit for controlling the second tuner to search for a broadcast station at a search frequency determined by the search frequency determination unit ;
A second storage unit that stores, as history information, a search frequency of a broadcasting station and position information at which the search frequency determination unit determines the search frequency;
The search frequency determination unit is configured to increase the search frequency of the broadcasting station corresponding to the history information when the search frequency of the history information corresponding to the current position read from the second storage unit is equal to or higher than a predetermined threshold. broadcast receiver and performs. A search is performed for a first tuner that is mounted on a mobile body and receives broadcast waves from a broadcast station, and a broadcast station that can be received by other than the broadcast station that the first tuner is receiving. A broadcast receiving device comprising a second tuner for receiving a data broadcast;
A first storage unit for storing a search result of a broadcasting station implemented in the second tuner;
When the amount of change in the search result contents of the broadcasting station read and written in the time series read from the first storage unit is equal to or greater than a predetermined threshold, the broadcast station search frequency is determined to be increased, and the time series changes. A search frequency determining unit for determining to reduce the search frequency of the broadcast station, when the amount of change in the content of the search result of the broadcast station is less than a predetermined threshold;
A search control unit for controlling the second tuner to search for a broadcast station at a search frequency determined by the search frequency determination unit ;
A second storage unit that stores, as history information, a search frequency of a broadcasting station and position information at which the search frequency determination unit determines the search frequency;
The search frequency determination unit is configured to increase the search frequency of the broadcasting station corresponding to the history information when the search frequency of the history information corresponding to the current position read from the second storage unit is equal to or higher than a predetermined threshold. broadcast receiver and performs.   3. The broadcast receiving apparatus according to claim 1, wherein the search frequency determining unit determines a search frequency for each frequency band in which a search for a broadcast station is performed by the second tuner. The first storage unit stores a search result of a broadcasting station for each frequency band implemented by the second tuner,
The search frequency determining unit determines, for each frequency band, whether or not the amount of variation in the search result content of the broadcasting station that is read back and forth in time series read from the first storage unit is equal to or greater than a predetermined threshold value, The broadcast station search result for each frequency band is determined to increase the search frequency of the broadcast station in all frequency bands when there is a change amount that is greater than or equal to a predetermined threshold. The broadcast receiving apparatus according to claim 2.   The broadcast according to claim 1 or 2, wherein the search frequency determination unit determines to lower the search frequency of a broadcast station when the second tuner preferentially performs reception of a data broadcast. Receiver device.   A navigation device comprising the broadcast receiving device according to claim 1.

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