JP2008060769A - Broadcasting receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a broadcasting receiver capable of highly accurately performing area presetting or network following, etc., without storing a huge amount of data as service area information. <P>SOLUTION: When the area presetting is performed, the present position of a vehicle is fetched, only transmission places in the arrival distance of the service area SAd of each transmission place are extracted, and then, one broadcasting network to be preset is selected, so as to extract the transmission places belonging to the selected broadcasting network among the extracted transmission places (steps 101-104). Secondly, reception sensitivity in the radio wave of the broadcasting station of each transmission place is determined based on the transmission place arrangement positions of the respective extracted transmission places, a present vehicle position, and the radio wave transmission angles of the transmission places, so as to read the transmission frequency of the transmission place with the largest reception sensitivity and a broadcasting station code from a broadcasting station database, and to store them in a preset memory (steps 105-107). When presetting is completed in the broadcasting stations of the whole broadcasting networks, the processing is terminated. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a broadcast receiving apparatus that receives a radio broadcast or a television broadcast, and more particularly to a broadcast receiving apparatus having an area preset or a network follow function.

In recent years, reception of television broadcast signals in mobile bodies such as in-vehicle television receivers has become popular. In such cases, the reception level changes every moment as the reception point moves. Since it cannot be received if it is away from the broadcasting station by a predetermined distance, the viewer has to re-select the channel by himself when receiving the same program continuously.
In addition, if the region changes, the received program broadcast is rarely broadcast on the same channel, and the viewer has to recognize the program in addition to the channel selection operation.

For this reason, the in-vehicle broadcast receiving apparatus is provided with an area preset function for searching for broadcast stations that can be received in the traveling area. That is, the area that can be satisfactorily received at each transmitting station is stored as service area information, and when performing area preset, the reception is performed at the vehicle position by referring to the service area information based on the current vehicle position. The channel data of possible broadcast stations is searched, and the searched data of receivable broadcast stations is displayed (for example, see Patent Document 1).
JP-A-8-65188

Also, in the in-vehicle broadcast receiving apparatus, the state of the radio wave constantly changes while the vehicle is running, so if the receiving state of the currently receiving broadcast station deteriorates, another broadcast station that broadcasts the same program Some have a network follow function for searching and switching to the reception frequency of the broadcasting station (see, for example, Patent Document 2).
JP 2000-209071 A

As a method for executing this network follow function, there are a two tuner network follow method and a one tuner network follow method.
In the 2-tuner network follow method, a sub-tuner that performs another reception frequency search for the same broadcast program as the main tuner is provided, and the main tuner's reception level is compared with the reception level received by the sub-tuner. The reception frequency is switched so that the reception level of the tuner is higher.

  Also, in the one tuner network follow method, an area where each transmitting station can receive well is stored as service area information, and the position of the vehicle is stored in the service area information storage means outside the area of the currently receiving broadcast station. Then, the reception frequency is changed to the broadcast frequency of a broadcast station that broadcasts the same program that includes the vehicle position in the service area.

As described above, the broadcast receiving device mounted on the mobile body is equipped with functions such as area preset and network follow, but the receivable area calculation algorithm when such area preset and network follow are performed. In the past, the receiving area was determined only by the “transmission position”, “frequency”, “height”, and “transmission output” of the transmitting station of the broadcasting station. When the service area is determined without considering the terrain in this way, even when there is a shield such as a mountain, it may be determined that reception is possible in the past even though reception is actually impossible.
Also, when performing one tuner network follow, as described above, since the broadcast station is switched without detecting the reception level of the broadcast station that actually receives, it is necessary to improve the accuracy of the broadcast receivable area. .

On the other hand, as the above service area information, the electric field strength at each point in the service area can be calculated in consideration of the terrain condition and stored as a database. In order to create a database of the electric field strength of points, it is necessary to store a huge amount of data, which is difficult to realize.
In addition, if a range in which a predetermined electric field strength can be obtained based on the electric field strength at each point in the service area is registered as a service area, it is only determined whether or not reception is possible at the vehicle position. There arises a problem that network follow cannot be executed.

  The present invention has been made in view of the above problems, and provides a broadcast receiving apparatus capable of performing area presetting, network follow-up, and the like with high accuracy without accumulating enormous data as service area information. With the goal.

  In order to achieve the above object, the broadcast receiving apparatus according to the present invention stores, as service area information, distance information of a plurality of reception sensitivities set for each predetermined reaching electric field strength for each transmitting station. Features.

  According to the broadcast receiving apparatus according to the present invention, instead of storing the electric field strength at each point in the service area of each transmitting station as a database, a plurality of points having reception sensitivity set for each predetermined reaching electric field strength. Is stored in the database as distance information, so that the amount of data can be greatly reduced, and area presets, network follow, etc. can be executed with high accuracy.

Embodiments of a broadcast receiving apparatus according to the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of an in-vehicle television broadcast receiving apparatus to which the present invention is applied. This broadcast receiving apparatus includes an antenna 1, a tuner 2, a control unit 3, a position detecting means 4, a broadcast station database 5, a signal. The processing unit 6, display 7, speaker 8, operation unit 9, and preset memory 10 are configured.
Note that the position detection means 4 may be a single position detection sensor, or a car navigation device can be used.

  The antenna 1 inputs the received broadcast wave to the tuner 2, and the tuner 2 selects the broadcast wave having the reception frequency set by the control unit 3, and outputs the selected received signal to the signal processing unit 6. On the other hand, the position information of the vehicle is input from the position detection means 4 to the control unit 3, and information on a broadcasting station having a frequency that can be received by the tuner 2 is input from the broadcasting station database 5.

The position detection means 4, for example, the car navigation device includes a current position detection unit including a GPS sensor and a gyro sensor and a map data storage unit that stores map data including road map data, and the control unit 3 determines the current position of the detected vehicle. To enter.
In addition, the broadcast station database 5 includes a broadcast network code, a broadcast station code, a transmission frequency, a transmission station installation position, a radio wave arrival distance for SAd area determination at each transmitting station in a frequency band that can be received by the tuner 2, as shown in FIG. , Information for each transmitting station such as a radio wave arrival distance record by SAa angle, a radio wave arrival distance record by SAb angle, a radio wave arrival distance record by SAc angle, and enclave information of reception sensitivity are stored.

The signal processing unit 6 detects and demodulates the reception frequency signal from the tuner 2, outputs an image signal to the display 7, outputs an audio signal to the speaker 8, and outputs a reception electric field strength of the reception signal to the control unit 3. To do.
The display 7 displays an image signal from the signal processing unit 6 and displays an operation image input from the control unit 3 to display operation screens of various functions. A touch panel switch is provided on the LCD display unit constituting the display unit of the display 7, and by pressing an item part displayed on the LCD display unit, a corresponding item can be selected and a function can be executed. .

The operation unit 9 is composed of a plurality of operation keys including preset keys, but a part or all of these operation keys can be substituted by the touch panel of the display 7.
The preset memory 10 stores the reception frequency of a broadcast station for each broadcast network (same network station) or the same broadcast station (including satellite stations) in a memory area corresponding to a plurality of preset keys of the operation unit 9.

  FIG. 3 is an example showing an example of a screen displayed on the display 7 and an arrangement of preset keys of the operation unit 9. In this example, the station names of receivable television broadcast stations preset on the display 7 are displayed. In addition, a plurality of preset keys 11 provided corresponding to each display broadcasting station are provided at the bottom, and by pressing the preset key 11 of the desired television broadcasting station, the broadcast of the desired television station can be viewed. can do.

Next, a method of creating the radio wave arrival distance record by SAa angle, the radio wave arrival distance record by SAb angle, and the radio wave arrival distance record by SAc angle in the broadcast station database will be briefly described.
First, as shown in FIG. 4, the ground height up to a predetermined distance (for example, 100 km) for each θ (for example, 10 °) with respect to the transmitting station of each broadcasting station is expressed as P ₁ km using the altitude numerical data. It is determined in steps (for example, 1 km step). Next, the receiving point is moved away from the transmitting station by P ₁ km centering on the transmitting station, and as shown in FIG. 5, after obtaining the shielding height h1 and shielding position that are most shielded from the transmitting station at the receiving distance point, transmission loss due to shielding Calculate After calculating the distance attenuation in free space based on the reception distance, the electric field strength at each reception point is obtained from the transmission power at the transmission station, the height of the transmission point, the cutoff loss, the distance attenuation, the transmission antenna directivity gain, etc. . As shown in FIG. 6A, the above calculation is performed for each distance P ₁ km in θ steps, and the electric field strength distribution in the service area is calculated.

Next, as shown in FIG. 6B, a strong electric field area in which the electric field intensity is SA dB or more with the cumulative probability PA%, based on the electric field intensity distribution at each transmission station θ step and distance P ₁ km. A medium electric field area SAb in which the electric field strength is SB dB with the cumulative probability PA% and a weak electric field area SAc in which the electric field strength is SC dB with the cumulative probability PA% are determined. Then, the arrival distance for each angle of each area is obtained as a radio wave arrival distance record for each SAa angle, a radio wave arrival distance record for each SAb angle, and a radio wave arrival distance record for each SAc angle. The information is stored in the broadcast station database 5 together with the defined reach of the area SAd. When radio waves from a plurality of broadcasting stations are transmitted from the transmitting station, the above data is calculated and stored for each broadcasting station.

On the other hand, depending on the terrain situation, the electric field strength distribution is not linear, and there may be enclaves as shown in FIG. 7, so the service area SAd is tiled for each tile size of P ₂ km, for example. As shown in FIG. 8 (a), the data for each broadcasting station is blank for the places that are not enclaves, and the sensitivity information for each broadcasting station is described for the enclaves as shown in FIG. 8 (b). By doing so, it is stored as the enclave information of the reception sensitivity. Then, at the time of area preset or network follow, priority is given to information on tiles having sensitivity information in the enclave information.

The television broadcast receiving apparatus according to the present embodiment is configured as described above. In this television broadcast receiving apparatus, the operation of the control unit 3 when executing the area preset is illustrated in the block diagram of FIG. 1 and FIG. The flowchart will be described.
When the user instructs an area preset from the operation unit 9, or when the user presses "Area" on the display screen of the display 7 shown in FIG. 3, the control unit 3 starts the area preset program shown in the flowchart of FIG. Then, after capturing the current position of the vehicle from the car navigation device 4 (step 101), the distance between the installation position of each transmitting station and the vehicle position is calculated, and the distance is within the reach of the area SAd of each transmitting station. Only a certain transmitting station is extracted (step 102).

  Next, the control unit 3 selects one of the preset broadcasting networks (step 103), and then refers to the broadcasting network code of each transmitting station in the broadcasting station database 5 from the transmitting stations extracted in step 102. Thus, the transmitting station belonging to the selected broadcast network is extracted (step 104). Then, the distance between the transmission station installation position and the current vehicle position and the radio transmission angle of the transmission station are calculated based on the transmission station installation position and the current vehicle position extracted at step 104, and these values are calculated. On the basis of the reception sensitivity enclave information of each transmitting station and the radio wave arrival distance record by SAa angle, the radio wave arrival distance record by SAb angle, and the radio wave arrival distance record by SAc angle. The reception sensitivity of the broadcast station radio wave, that is, SAa, SAb, SAc, SAd is determined (step 105).

  Next, when each of the determined transmitting stations has the highest receiving sensitivity, for example, if there is a transmitting station whose vehicle position is the strong electric field area SAa, there is no transmitting station whose vehicle position is the strong electric field area SAa. The transmitting station whose vehicle position is the middle electric field area SAb is selected (step 106). When there are a plurality of transmitting stations whose vehicle positions are in the strong electric field area SAa, the control unit 3 selects a transmitting station close to the current vehicle position or a transmitting station with a small ratio of l (distance) / SAa. To do.

  Next, the control unit 3 reads out the transmission frequency and broadcasting station code of the selected transmitting station from the broadcasting station database 5, and stores the broadcasting station name corresponding to the frequency and the broadcasting station code in the corresponding storage area of the preset memory 10. Memorize (step 107). If the vehicle is not in the service area of all the broadcasting stations of the broadcasting network, the preset memory 10 is blank and the broadcasting station of the broadcasting network is not displayed on the display 7.

Thereafter, the control unit 3 determines whether or not the broadcasting stations of all broadcasting networks have been selected, that is, whether or not the reception frequency and the broadcasting station name (including blanks) are stored in all the memory areas of the preset memory 10. (Step 108), when it is determined that the broadcasting stations of all broadcasting networks are not selected, the process returns to Step 103, the next broadcasting network is selected, and when it is determined that the broadcasting stations of all broadcasting networks are selected, The process ends.
As a result, when the broadcast receiving apparatus is turned on, the preset stations on each broadcasting network are displayed on the display 7 as shown in FIG. 3, so the preset key 11 of the desired TV station is pressed. Thus, it is possible to view a broadcast of a desired television station.

Next, the operation when performing network follow will be described with reference to the block diagram of FIG. 1 and the flowchart of FIG.
The controller 3 executes the network follow program shown in the flowchart of FIG. 10 at regular intervals during broadcast reception. When this program is started, the controller 3 determines that the received electric field strength of the currently received broadcast wave is a predetermined value. It is determined whether or not the value is lower than the value (step 201). If it is determined that the received electric field strength of the currently received broadcast wave is greater than the predetermined value, the process is terminated.

  On the other hand, when it is determined that the received electric field strength of the currently receiving broadcast station has decreased below a predetermined value, the control unit 3 captures the current position of the vehicle from the position detection means 4 (step 202), and then transmits each transmission. The distance between the installation position of the station and the vehicle position is calculated, and only the transmitting station whose distance is within the reach of the area SAd of each transmitting station is extracted (step 203).

  Next, the control unit 3 refers to the broadcasting station code of each transmitting station in the broadcasting station database 5 from among the transmitting stations extracted in step 203, and thereby the same broadcasting station code as the currently receiving broadcasting station. (Step 204), the distance between the transmission station installation position and the current vehicle position based on the transmission station installation position and the current vehicle position of each transmission station extracted in step 204, and the transmission station , And based on these values, refer to the enclave information of the receiving sensitivity of each transmitting station, the radio wave arrival distance record by SAa angle, the radio wave arrival distance record by SAb angle, and the radio wave arrival distance record by SAc angle. Thus, the reception sensitivity of the broadcast radio wave at each transmitting station at the vehicle position is determined (step 205).

  Next, it is determined whether or not there is a transmitting station having a receiving sensitivity higher than the receiving sensitivity of the broadcasting station currently receiving (step 206), and the receiving sensitivity of the broadcasting station currently receiving is determined. If it is determined that there is a transmitting station having higher receiving sensitivity, the transmission frequency of the transmitting station is read from the broadcast station database 5 and the tuner 2 is controlled to receive the frequency signal (step 207).

  For example, when the receiving sensitivity of the transmitting station currently receiving is the middle electric field area SAb, and there is a transmitting station whose vehicle position is the strong electric field area SAa, the control unit 3 causes the vehicle position to be a strong electric field. The tuner 2 is controlled so as to receive the broadcast signal of the transmitting station that is the area SAa. If the receiving sensitivity of the transmitting station currently receiving is the strong electric field area SAb, and the receiving sensitivity of another transmitting station having a high receiving sensitivity is also the strong electric field area SAb, the image or sound Do not switch transmitters to prevent disruption. Further, when the receiving sensitivity of the transmitting station that is currently receiving is the middle electric field area SAb, and there are a plurality of transmitting stations whose vehicle positions are the strong electric field areas SAa, the control unit 3 determines the current vehicle position. Select a transmitter near to and switch the received radio wave.

  On the other hand, when it is determined in step 206 that there is no transmitting station having a receiving sensitivity higher than the receiving sensitivity of the currently receiving transmitting station, the control unit 3 selects the broadcasting station database from the transmitting stations extracted in step 203. 5 is extracted by referring to the broadcasting network code of each transmitting station 5 (step 208).

  Next, the control unit 3 calculates the distance between the transmission station installation position and the current vehicle position and the radio wave transmission angle of the transmission station based on the transmission station installation position of each transmission station and the current vehicle position extracted in step 208. Based on these values, the vehicle position can be determined by referring to the receiving point information of each transmitting station, the radio wave arrival distance record by SAa angle, the radio wave arrival distance record by SAb angle, and the radio wave arrival distance record by SAc angle. The broadcast radio wave reception sensitivity of each transmitting station is determined (step 209).

Next, it is determined whether or not there is a transmitting station having a receiving sensitivity higher than the receiving sensitivity of the broadcasting station currently receiving (step 210), and the receiving sensitivity of the broadcasting station currently receiving is determined. If it is determined that there is no transmitting station having higher reception sensitivity, the process is terminated.
On the other hand, when it is determined that there is a transmitting station having a higher receiving sensitivity than the receiving radio wave sensitivity of the transmitting station that is currently receiving, the transmitting frequency of the transmitting station is read from the broadcasting station database 5 and the frequency signal is The tuner 2 is controlled so as to receive it (step 211).

  As described above, since the transmitting station having the same broadcasting station code as the currently receiving broadcasting station is selected based on the receiving sensitivity at the vehicle position, network follow-up can be executed with high accuracy. Also, if there is no other transmission station with the same broadcast station code and high reception sensitivity, a transmission station with high reception sensitivity is selected from the transmission stations with the same broadcast network code. Even when the user is away from the service area of a broadcasting station, the same broadcast can be viewed.

  In the above embodiment, an example in which the broadcast receiving apparatus of the present invention is applied to a television broadcast receiving apparatus has been described. However, the broadcast receiving apparatus of the present invention can also be applied to an AM or FM radio receiving apparatus. The radio receiving apparatus to which the present invention is applied can also execute the above-described area preset and network follow, but can also execute a candidate station list display, the same broadcast station search, an alternative preset station search, and the like.

  In the case of candidate station list display, by pressing “candidate list” on the broadcast station display screen of FIG. 11A, the control unit searches for the transmitting station of the same broadcast station as the current receiving station, for example, Radio 80. As shown in FIG. 11 (b), the fields are sorted in the descending order of electric field strength, that is, in descending order of reception sensitivity, and are displayed in a list on the display. In this case, as described above, since it is possible to distinguish between the same broadcast station and different broadcast stations of the same series (same broadcast network), it is possible to display them by dividing them into “same station” and “affiliated station”.

  Further, in the case of the same broadcast station search, by pressing “Search” on the broadcast station display screen of FIG. 12A, the control unit can search for the same broadcast station with respect to the current receiving station in the same manner as the above network follow. The transmitting station is searched and reception is switched to the broadcasting station with the highest receiving sensitivity, and is displayed on the display as shown in FIG. When performing the same broadcast station search, it is necessary to search all frequencies in a normal radio receiving apparatus. However, in a radio receiving apparatus to which the present invention is applied, switching station stations are determined to some extent by using a broadcast station database. Since it can narrow down, search time can be shortened.

  Further, in the case of alternative preset station search, when the reception state of a preset broadcast station is deteriorated, the above-mentioned network follow can be performed by long-pressing the station on the preset station display screen of FIG. Similarly, search is made for a candidate station for switching to the same broadcast station as the preset station, and reception is switched to a receivable station, and is displayed on the display as shown in FIG.

  On the other hand, in the above embodiment, only the current position of the vehicle is fetched from the position detecting means, but the reception sensitivity of the current receiving station obtained from the above broadcasting station database is input to the position detecting means, for example, the car navigation device. By doing so, it is also possible to display the reception sensitivity for each mesh on the navigation map in different colors, so that the user can recognize at a glance how far the current receiving station can receive. Can do.

The block diagram which shows the structure of the vehicle-mounted television broadcast receiver to which this invention is applied. An example of information stored in a broadcast station database. An example of a display screen and an arrangement of keys on the operation unit. The figure for demonstrating the calculation method of surface height. The figure which shows the shielding condition of the electromagnetic wave from a transmitting station. An example of an application screen for calculating electric field strength distribution in a service area and different reception sensitivity areas. An example of an enclave that occurs in the electric field strength distribution. An example of information stored in a tile. The flowchart which shows an effect | action when performing an area preset. The flowchart which shows the effect | action in the case of performing a network follow. An example of the execution screen of candidate station list display. An example of the same broadcast station search execution screen. An example of an alternative preset station search execution screen.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Antenna 2 Tuner 3 Control part 4 Position detection means 5 Broadcasting station database 6 Signal processing part 7 Display 8 Speaker 9 Operation part 10 Preset memory 11 Preset key

Claims (5)

Broadcast receiving means for receiving a broadcast from a broadcasting station;
Position detecting means for detecting the position of the broadcast receiving device;
A broadcasting station database in which areas where broadcasting can be received successfully are stored as service area information;
Control means for setting the reception frequency of the broadcast receiving means based on the output of the position detecting means and information from the broadcast station database;
The broadcast receiving apparatus, wherein the broadcast station database stores distance information of a plurality of reception sensitivities set for each predetermined reaching electric field intensity as the service area information.   2. The broadcast receiving apparatus according to claim 1, wherein the broadcast station database stores at least information of a broadcast station code, a broadcast network code, a transmission frequency, and a transmission station installation position for each transmission station. .   The broadcast receiving apparatus according to claim 1, wherein the broadcast station database stores reception sensitivity areas of enclaves as tile information.   The broadcast receiving apparatus according to any one of claims 1 to 4, wherein the control means executes an area preset based on an output of the position detecting means and information from the broadcast station database. .   The broadcast receiving apparatus according to any one of claims 1 to 4, wherein the control means performs network follow based on an output of the position detecting means and information from the broadcast station database. .

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