JP2019169893A - Electronic apparatus and own station channel selection method - Google Patents

Abstract

To provide an electronic apparatus capable of controlling whether or not scan operation is executed automatically from positional information, when reception sensitivity of a broadcast wave is deteriorated.SOLUTION: A scan control program 300 executed by an on-vehicle system includes: receiving means for receiving a broadcast wave broadcasted from a broadcasting station; detection means for detecting a reception sensitivity of the broadcast wave received by the receiving means; acquisition means for acquiring positional information of a mobile; search means for making the receiving means search a broadcast station that can be selected, in response to deterioration of the detected reception sensitivity; storage means for acquiring the positional information at a point where the reception sensitivity is deteriorated, from the acquisition means, and storing search history information containing the point and the search result; and search control means for controlling the search means on the basis of the search history information.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an electronic apparatus having a reception function for digital terrestrial broadcasting, and more particularly to an automatic search function for a broadcast station when reception sensitivity of a broadcast wave being received is deteriorated.

  In recent years, television broadcasting and radio broadcasting have shifted globally from analog broadcasting to digital broadcasting, and in-vehicle electronic devices that support this digital broadcasting have been developed so that terrestrial digital TV broadcasting can be viewed. Vehicles equipped with various in-vehicle systems are becoming popular. In an electronic device having such an in-vehicle system, there is a case where the electric field sensitivity of the receiving station is reduced. In such a case, it is necessary to switch to an alternative broadcasting station. Generally, another broadcast station that can be received is automatically scanned (channel search), and among the receivable broadcast stations, the same relay station or affiliated station as the broadcast station of the program that was viewed before the reception deteriorated If so, the broadcast station is selected so that the same program can be continuously viewed.

  The operation of sequentially scanning the entire band of the reception frequency takes a certain time, and during this time, viewing is interrupted. For example, if you travel in a place where the reception sensitivity temporarily decreases, such as a tunnel, the scanning operation will be performed automatically, and even if the reception sensitivity returns to normal, the scan has not yet been completed. Arise. Therefore, based on the guidance information from the car navigation information acquisition unit, when GPS (Global Positioning System) cannot be measured, it is determined that the broadcast wave cannot be received, and the receiving device prohibits the automatic search for the broadcast station. Is disclosed (Patent Document 1).

JP-A-8-265107

  The problems of the prior art will be described in detail with reference to FIG. 1 and FIG. FIG. 1A shows a state in which broadcast waves can be received. When the host vehicle 1 travels in an area where there are no obstacles or the like, the receiving device receives the broadcast wave from the broadcasting station 2 well, and the GPS receiving device receives the GPS signal from the GPS satellite 3 well. . However, the scanning operation is prohibited when the host vehicle 1 travels in an area where the GPS signal is blocked, such as the tunnel 4 as shown in FIG. 1B, and the GPS signal from the GPS satellite 3 cannot be detected. Has been controlled. However, for example, when the host vehicle 1 travels in a broadcast wave blocking area where a high-rise building 5 or the like as shown in FIG. 1 (C) stands up, a GPS signal can be received, but a broadcast wave from the broadcast station 2 is temporarily received. In a situation where reception is not possible, the scanning operation is started because the GPS signal can be received.

  FIG. 2 is a diagram schematically illustrating a problem of a conventional receiving apparatus. The start point of the unreceivable area is A, the end point is B, and the AB section is the broadcast wave unreceivable area. If the scanning operation is not executed when the host vehicle enters the unreceivable area, the reception sensitivity returns to normal when passing through the end point B of the unreceivable area, and viewing of the broadcast wave is resumed. However, when the scanning operation is executed and the scanning is completed at the point C beyond the AB section, there arises a problem that the user cannot view the broadcast wave in the BC section.

  The present invention has been made to solve such problems, and an object of the present invention is to provide an electronic device that does not search for an unnecessary broadcast station when the reception sensitivity of a broadcast wave is reduced. .

  An electronic apparatus according to the present invention is an electronic apparatus having a receiving function of a broadcasting station mounted on a mobile body, the receiving means receiving a broadcast wave broadcast from a broadcasting station, and the receiving means Detecting means for detecting reception sensitivity of a broadcast wave; acquisition means for acquiring position information of the moving body; and a broadcast station that can be selected by the receiving means in response to a decrease in detected reception sensitivity. Search means for searching, position information at the point where the reception sensitivity is lowered is acquired from the acquisition means, storage means for storing search history information including the point and search results, and the search based on the search history information An electronic apparatus comprising search control means for controlling the means.

  In one embodiment, the search result includes information that the channel of the broadcast station before performing the search and the channel of the broadcast station after performing the search are the same, and the search control means includes the mobile unit. If the location information corresponds to the stored point, searching for the broadcasting station by the searching means is prohibited. In one embodiment, the search result includes information that the search is interrupted by a user, and the search control means, when the position information of the mobile object corresponds to the stored point, The search for the broadcasting station by the searching means is prohibited. In one embodiment, the searching means causes the receiving means to search for all broadcast stations from the minimum frequency to the maximum frequency. In one embodiment, the search control unit prohibits the search unit from searching for a broadcast station when the position information of the mobile object is within a predetermined range of the stored point. In one embodiment, the search control means prohibits the search means from searching for a broadcasting station for a predetermined time after the mobile object passes the stored point. In one embodiment, the search history information further includes a traveling direction of the moving object, and the search control means is configured to detect the position information and the traveling direction of the moving object corresponding to the point and the traveling direction of the search history information. The search for broadcasting stations by the search means is prohibited. In one embodiment, the receiving means is capable of receiving a plurality of broadcast waves, and the searching means is connected to another broadcasting station while the receiving means is receiving one broadcasting station. To search. In one embodiment, the search means searches for all broadcast stations when the search for the relay station or affiliated station by the receiving means fails.

  The automatic channel selection broadcast according to the present invention is an automatic channel selection method provided with a reception function of a broadcast station mounted on a mobile body, and obtains position information of the mobile body and broadcasts from the received broadcast station Detects wave reception sensitivity, searches for broadcast stations that can be selected in response to a decrease in reception sensitivity, obtains location information at a point where reception sensitivity has decreased, and includes the point and search results History information is stored, and it is controlled whether or not a searchable broadcast station is searched based on the search history information.

  According to the present invention, at the point where the reception sensitivity of the broadcast wave is lowered, when the point is stored in the history information, the search for the broadcasting station in response to the decrease in the reception sensitivity is prohibited, thereby making it unnecessary broadcast Station search can be suppressed.

It is a figure explaining the subject of the conventional receiver. It is a figure for demonstrating the subject of the conventional receiver. It is a block diagram which shows the example of whole structure of the vehicle-mounted system which concerns on embodiment of this invention. It is a block diagram which shows the example of whole structure of the broadcast receiving part which concerns on embodiment of this invention. It is a block diagram which shows the functional structure of the scan control program which concerns on embodiment of this invention. It is an example figure of search history information concerning an embodiment of the present invention. It is a flowchart explaining the control operation | movement of the all-station scan which concerns on embodiment of this invention. It is a block diagram which shows the functional structure of the background search control program which concerns on the modification of this invention. It is a flowchart explaining the control operation | movement of the background search which concerns on the modification of this invention. It is an example figure which shows the prohibition area which concerns on embodiment of this invention.

  Next, embodiments of the present invention will be described with reference to the drawings. The electronic device of the present invention may be either a device that is fixedly mounted on a moving body such as an automobile, a device that can be brought into the moving body by a user, or a device that is removable from the moving body. The electronic device of the present invention has a function of receiving a television broadcast, but other functions include, for example, a navigation function, a function of reproducing audio data and video data, a function of receiving a radio broadcast, and application software. The function to perform may be provided integrally. The electronic device can be, for example, a notebook PC, a tablet PC, a personal computer, an in-vehicle device, a navigation device, a broadcast receiving device, or the like. In addition, the electronic device can be connected to a communication bus in the vehicle or a bus equivalent thereto, and can have a function of acquiring information such as devices mounted on the vehicle via the communication bus. In the following description, as an example of an electronic device, an in-vehicle system provided with a digital broadcast receiver in a navigation device mounted on a vehicle as a moving body will be described as an example.

  In addition, the digital broadcast receiver in the description of the present embodiment will be described using an example including four tuners, but the present invention is not limited to this, and has a search function for a broadcast station. Applicable to all digital broadcast receivers. Therefore, in an embodiment, the present invention may be applied to a digital broadcast receiver including a single tuner. In this embodiment, a function of switching between a full-segment program and a one-segment program is provided. However, this is not an essential requirement and may not be provided in other embodiments. In the following description, the scanning operation of the broadcasting station in all bands is referred to as all station scanning.

  FIG. 3 is a block diagram showing an example of the overall system configuration of the in-vehicle system 10 according to the embodiment of the present invention. The in-vehicle system 10 includes an input unit 11, a position information detection unit 13, a navigation unit 15, a broadcast reception unit 17, an antenna 171, a storage unit 19, an audio output unit 21, a display output unit 23, a display 231, and a control unit 25. Composed.

  The input unit 11 allows the user to input various information to the in-vehicle system 10. The input unit 11 includes, for example, an input key device, a voice input recognition device, a touch panel, and the like, and the user inputs various instructions such as menu selection operation, channel switching, map scrolling, destination setting, and the like via the input unit 11. can do. Moreover, you may be comprised by the touchscreen etc. which were attached to the display 231. FIG. An operation signal corresponding to the operation content is output to the control unit 25.

  The position information detection unit 13 detects the current position of the host vehicle. The position information detection unit 13 detects the position of the vehicle based on, for example, positioning using a GPS signal and positioning using an autonomous navigation sensor. The autonomous navigation sensor includes, for example, an azimuth sensor such as an angular velocity sensor and a geomagnetic sensor, a vehicle speed sensor such as a vehicle speed pulse sensor, and the like. The vehicle position information detected by the position information detection unit 13 is provided to the navigation unit 15. Note that the vehicle position information may be acquired by accessing a position information distribution site or a distribution server using a communication function provided in the in-vehicle system.

  The navigation unit 15 executes a navigation function in cooperation with the control unit 25. When the destination is set by the user, the navigation unit 15 searches for a route from the vehicle position detected by the position information detection unit 13 to the destination, and the searched route is output to the audio output unit 21 and the display output. Output from the unit 23. Alternatively, a road map around the vehicle position is guided. In addition, the navigation unit 15 calculates the estimated arrival time to the waypoint and the destination in consideration of traffic jam information and the like, and performs route guidance that also includes the arrival time. In addition, data necessary for navigation can be acquired from the storage unit 19, but if it has a communication function, it is also possible to acquire necessary data from an external server.

  As shown in FIG. 4, the broadcast receiver 17 includes antennas 171a to 171d, tuners 173a to 173d, a diversity synthesizer 175, an error corrector 177, a demultiplexer 179, an audio decoder 181, a video decoder 183, a data decoder 185, An audio selection unit 187 and a video selection unit 189 are included. The antennas 171a to 171d receive radio waves (broadcast waves) of terrestrial digital broadcasting and provide them to the tuners 173a to 173d. The tuners 173a to 173d select a broadcast station or channel frequency in accordance with a user input from the input unit 11 or a control signal from the control unit 25, and receive broadcast waves from the selected broadcast station. Further, the received signal is demodulated to generate a transport stream signal (hereinafter, TS), which is provided to the diversity combining unit 175.

  The diversity combining unit 175 receives signals from each tuner and generates a diversity combined TS. Preferably, diversity combining section 175 controls the phase of the signal from each tuner and combines the phase-controlled TS. In addition to the phase control method, the diversity combining unit 175 may perform, for example, a method for selecting a signal with the maximum power or a method for applying a weight proportional to the signal power.

  The error correction unit 177 corrects an error that occurs during transmission and outputs it to the demultiplexer unit 179. At this time, a BER (Bit Error Rate) indicating an error rate is output to the control unit 25. The error rate BER corresponds to the number of tuners combined by the diversity combining unit 175. For example, the broadcast station currently being viewed by two tuners is received, and the remaining two tuners are searched for alternative stations. If so, the error rate for each two-diver combination is output.

  The demultiplexer unit 179 separates the audio stream, the video stream, and the data stream from the multiplexed TS, respectively. The audio stream is an audio decoder unit 181, the video stream is a video decoder unit 183, and the data stream is a data decoder unit 185. Respectively. The data stream includes an information stream for data broadcasting, and further includes a network information table (NIT) and an event information table (EIT). The EIT includes an event ID or the like for identifying program information, and this event ID is used to determine whether or not the full segment program and the one segment program are the same. The NIT includes information on relay stations and affiliated stations that are broadcasting the same program as the receiving broadcast station.

  The audio decoder unit 181 decodes the input audio stream. At this time, the audio streams of the full segment broadcast program and the one segment broadcast program are separately decoded and output to the audio selection unit 187. The video decoder unit 183 decodes the input video stream. At this time, the video streams of the full segment broadcast program and the one segment broadcast program are separately decoded and output to the video selection unit 189. The data decoder unit 185 decodes the data stream and outputs the result to the control unit 25.

  The audio selection unit 187 selects an audio signal of a full segment broadcast program or a one segment broadcast program in accordance with a control signal from the control unit 25. That is, when the reception sensitivity is good, the audio signal of the full segment broadcast program is selected, and when the reception sensitivity is poor, the audio signal of the noise-resistant one segment broadcast program is selected. Similarly, the video selection unit 189 selects an audio signal of a full segment broadcast program or a one segment broadcast program in accordance with a control signal from the control unit 25 based on reception sensitivity. The audio signal and video signal selected by the audio selection unit 187 and the video selection unit 189 are output from the audio output unit 21 and the display output unit 23.

  Returning to FIG. 3, the storage unit 19 stores road map data required by the navigation unit 15 and various program data executed by the control unit 25. The road map data and the like may be acquired from an external server as needed and stored in the storage unit 19. Furthermore, the storage unit 19 stores search history information including search position information and search results created by a history information creation unit 340 described later.

  The audio output unit 21 D / A converts the audio signal (television audio) provided from the broadcast receiving unit 17 and the audio signal (guidance guidance audio) provided from the navigation unit 15 and outputs the audio via a speaker. The display output unit 23 selectively displays the video signal (television image) provided from the broadcast receiving unit 17 and the video signal (map image) provided from the navigation unit 15 on the display 231 according to the operation.

  The control unit 25 controls the overall operation of the in-vehicle system 10. In the present embodiment, the operation of the navigation unit 15 and the broadcast receiving unit 17 is controlled by executing a program that is configured by a central processing unit, a microcomputer, or a microprocessor and stored in the storage unit 19. In the present embodiment, the control unit 25 executes a scan control program 300 that controls whether or not to perform all-station scanning based on conditions.

  FIG. 5 is a block diagram showing a functional configuration of the scan control program 300 according to the present embodiment. The scan control program 300 includes a reception sensitivity detection unit 310, a history information collation unit 320, an all-station scan execution unit 330, and a history information creation unit 340.

  The reception sensitivity detector 310 detects whether the current broadcast wave reception sensitivity is good or low. Preferably, the carrier-to-noise ratio (C / N value: Carrier to Noise Ratio value) of the signal that is diversity-combined by diversity combining section 175 is used as information for determining reception sensitivity. In this case, if the C / N value exceeds the threshold, it is determined that the reception sensitivity is good, and if the C / N value is equal to or less than the threshold, it is determined that the reception sensitivity has decreased. In an embodiment, the reception sensitivity can also be determined from the error rate (BER) output from the error correction unit 177. In this case, if the error rate (BER) is equal to or higher than a threshold value, the reception sensitivity is lowered. If the error rate (BER) is less than the threshold, it is determined that the reception sensitivity is good. In an embodiment, it is also possible to calculate a C / N value from an error rate (BER) and determine reception sensitivity from the calculated C / N value.

  Also, in this embodiment, four tuners are provided, and when reception is performed with these four tuners, a decrease in reception sensitivity is detected by comparing the C / N value of a signal synthesized by four divers with a threshold value. To do. In addition, for example, when receiving a broadcast wave currently being viewed by two tuners and searching for an alternative station using the remaining two tuners, such as a background search function, the reception of the broadcast wave currently being viewed is received. The C / N value of the signal combined with 2 divers assigned to is compared with the C / N value of the signal combined with 2 divers assigned to the search of another broadcasting station.

  When the reception sensitivity detection unit 310 detects that the reception sensitivity is reduced, the history information collation unit 320 responds to the position included in the search history information stored in the storage unit 19. From the information, a check is made to see if there is a thing at the same point as the current position. In response to detection of a decrease in reception sensitivity by reception sensitivity detection unit 310, all-station scan execution unit 330 scans frequencies from the lower limit to the upper limit of the reception band of broadcast waves and detects receivable broadcast stations.

  When the search result of the all-station scan execution unit 330 satisfies a predetermined condition, the history information creation unit 340 obtains the position information at the point where the reception sensitivity is reduced, which has started the all-station scan, from the position information detection unit 13. Acquire and memorize. As a predetermined condition in the present embodiment, when the channel (broadcasting station frequency) is the same before and after performing all-station scanning, a point where the reception sensitivity is reduced is stored. The fact that the channel is the same before and after the all-station scan has been performed can be assumed to be due to a temporary decrease in the broadcast wave cut-off area, not a decrease in reception sensitivity due to separation from the relay station or affiliated station. is there.

  Therefore, in the present embodiment, the channel that is currently received before the all-station scan is temporarily recorded, and the channel that has been scanned and switched by the all-station scan execution unit 330 is the same as the channel before the all-station scan. If it is the same, the history information creation unit 340 stores the search history information including the result and the position information at the point where the reception sensitivity is reduced in the storage unit 19.

  Further, in the present embodiment, when the all-station scan is performed, the history information creation unit 340 detects the location information at the point where the reception sensitivity is lowered when it is detected that the user has instructed the all-station scan to be interrupted. The included search history information is stored in the storage unit 19. Thereby, the point where the user feels that the all-station scan is unnecessary is stored.

  FIG. 6 is a diagram showing an example of search history information according to the embodiment of the present invention. The search history information includes a record ID for identifying a search history, information on date and time, information on longitude and latitude indicating the coordinates of the point, information on the traveling direction of the car when passing the point, information on the search result, etc. Contains. As a calculation method of the passing direction, for example, the traveling direction of the vehicle may be calculated based on a change in the current position of the vehicle after a predetermined time from the current position acquired when the reception sensitivity is reduced. It may be calculated from the up or down lane information on which the vehicle is traveling. Further, the passing direction may be recorded in the direction of travel. In other embodiments, the present invention is not limited to this, and can be modified. Information on date / time, passage direction, and search result may be omitted, and it is only necessary to record at least position information satisfying the condition.

  Next, the control operation for all-station scanning according to the embodiment of the present invention will be described with reference to the flowchart of FIG. First, the reception sensitivity detection unit 310 determines whether the terrestrial digital broadcast is being received (viewed) by the broadcast receiving unit 17 (S101). If the terrestrial digital broadcast is being received, the reception sensitivity detection unit 310 detects the presence or absence of a decrease in reception sensitivity (S103). The reception sensitivity detection unit 310 monitors the reception sensitivity of the currently received broadcast wave as needed. For example, when the C / N value falls below a threshold, the reception sensitivity detection unit 310 detects a decrease in reception sensitivity and proceeds to the next step. .

  Next, in response to detection of a decrease in reception sensitivity, the position information detection unit 13 acquires information on the current position of the host vehicle via the position information detection unit 13 (S105). At this time, information on the traveling direction of the host vehicle is also acquired. Next, the history information matching unit 320 checks whether or not there is a matching point from the current position where the reception sensitivity has decreased and the search history information stored in the storage unit 19 (S107). For example, the history information collating unit 320 performs collation by determining whether the longitude and latitude of the current position and the longitude and latitude of the point included in the search history information are the same or approximate. Also, the traveling direction is collated to determine whether it is the same direction as the passing direction included in the search history information. Thereby, the accuracy of collation is further improved.

  If the search history information matches the search history information, the all-station scan execution unit 330 prohibits execution of the all-station scan (S109). As a result, it is not necessary to perform a full station scan at a point where the reception sensitivity temporarily decreases. The process ends after the all-station scan execution is prohibited. Next, as a result of collation with the search history information, if they do not match, the all station scan is executed by the all station scan execution unit 330 (S111). At this time, the channel of the broadcast station currently being viewed is temporarily recorded in the storage unit 19.

  While the all-station scan is being performed, the all-station scan interruption operation from the user or the like is detected (S113). Here, when an interruption operation by the user is detected, search history information is created by the history information creation unit 340 (S115). In response to the detection of the interruption operation, the history information creation unit 340 acquires position information (including the traveling direction) of the point where the reception sensitivity has been reduced, which has led to the all-station scan, as shown in FIG. Search history data is generated and recorded in the storage unit 19. This makes it possible to automatically prohibit the start of all-station scanning when the vehicle travels the same point from the next time. Then, after creating the search history information, the process is terminated.

  Returning to S113, the all-station scan is completed without any interruption operation by the user (S117). Then, it is determined whether the channel switched by the all station scan is the same as the recorded channel before the all station scan is executed (S119). Here, if the channels are the same before and after the all-station scan, search history information is created by the history information creation unit 340 (S115). In response to the fact that the channel is the same before and after the all-station scan, the history information creation unit 340 obtains the position information (including the traveling direction) of the point where the reception sensitivity has decreased, which led to the all-station scan, Search history data as shown in FIG. 6 is generated and recorded in the storage unit 19. As a result, all-station scanning can be automatically prohibited when the vehicle travels the same point from the next time. Then, after creating the search history information, the process is terminated.

  Returning to S119, if the channel is not the same as the channel before the all station scan execution, it can be said that the all station scan at this point is necessary, so the process is not performed by the history information creating unit 340 without creating the search history information. finish.

As described above, points that do not require all-station scanning are stored at any time, and execution of all-station scanning is automatically prohibited when passing through the point again, thereby eliminating unnecessary all-station scanning. It becomes like this. In addition, by prohibiting the execution of the all-station scan as in the present embodiment, the time that cannot be viewed by the all-station scan although the broadcast wave such as the BC section can be received as described in the problem of the prior art in FIG. It becomes possible to view from the point, and the viewing time can be extended by the BC section. For example, if it takes about 1 minute to scan all stations, and if it passes through a non-receivable area in 10 seconds, it could not be viewed for 50 seconds in the past, but the present invention is implemented. Thus, the viewing time can be increased for 50 seconds compared to the conventional case.

  Next, a modified example of the present embodiment will be described. In the above embodiment, a digital broadcast receiver having an all-station scan function has been described as an example. However, in this modified example, a digital broadcast receiver that performs an alternative station search and a background search (relay station or affiliated station) is described. explain. The background search is to search for another broadcast station with the remaining tuners while receiving a desired broadcast station with one or a plurality of tuners when the reception sensitivity of the broadcast wave is lowered.

  When executing this background search, when the error correction unit 177 outputs the BER indicating the error rate to the control unit 25, for example, the broadcast station currently being viewed by two tuners is received, and the remaining two When the tuner is searching for an alternative station, the error rate of each 2-diver combining is output. The C / N value indicating the reception sensitivity in the background search is, for example, when a broadcast wave currently being viewed by two tuners is received and an alternative polar search is performed by the remaining two tuners. Threshold value comparison between the C / N value of the 2-diverged signal assigned to receive the broadcast wave in the middle and the C / N value of the 2-diverged signal assigned to the search of other broadcasting stations Will come to be. This threshold value comparison can detect a decrease in reception sensitivity.

  In the modification, the control unit 25 executes the background search control program 400. FIG. 8 shows a functional configuration of the background search control program 400. The background search control program 400 includes a reception sensitivity detection unit 410, a history information matching unit 420, a background search execution unit 430, and a history information creation unit 440. The reception sensitivity detection unit 410, the history information collation unit 420, and the history information creation unit 440 have the same functions as the reception sensitivity detection unit 310, the history information collation unit 320, and the history information creation unit 340 shown in FIG. Therefore, explanation is omitted.

  In response to the reception sensitivity detection unit 410 detecting a decrease in reception sensitivity, the background search execution unit 430 uses two tuners that are different from the two tuners that are currently receiving the broadcast station being viewed, Perform an alternative station search in the background. This alternative station search is a function of acquiring information on each broadcast station described in advance in the NIT or the like at the time of initial scan, and searching for an alternative relay station and affiliated station from a selectable list. . Preferably, a search is made from a relay station that does not take a long time to search, and when there is no relay station, a transition is made to a search for an affiliated station. Depending on the embodiment, if a broadcast station with good reception sensitivity is not found even after searching for affiliated stations, an all-station scan may be performed.

  Next, the background search control operation according to the modification will be described with reference to the flowchart of FIG. The same processing is performed up to S105 in FIG. As a result of collating with the search history information in S207, if the point where the current reception sensitivity is reduced matches the point recorded in the search history information, the background search execution unit 430 executes the alternative station search. It is prohibited (S209). As a result, it is not necessary to perform a background search unnecessarily at a point where the reception sensitivity temporarily decreases. After the background search execution is prohibited, the process is terminated. Next, as a result of collation with the search history information, if they do not match, the background search execution unit 430 executes an alternative station search (S211). At this time, the channel of the broadcast station currently being viewed is temporarily recorded in the storage unit 19.

  In the background search, for example, an alternative station search is performed with two tuners (S213). During the background search, since the viewer continues to watch the broadcast stations received by the two tuners, the background search interruption operation is basically not instructed by the user. Therefore, in the modified example, the point is not stored by the interruption operation.

  The alternative station search by the background search execution unit 430 is completed (S215). At this time, it is determined whether the broadcast station switched by the alternative station search is the same as the recorded channel before the background search is executed (S217). . If the channels are the same before and after the background search, search history information is created by the history information creation unit 440 (S219). In response to the fact that the channel is the same before and after the background search, the history information creation unit 340 obtains the position information (including the traveling direction) of the point where the reception sensitivity has been reduced, which led to the background search. Then, search history data as shown in FIG. 6 is generated and recorded in the storage unit 19. This makes it possible to automatically prohibit the start of the background search when the vehicle travels the same point from the next time. Then, after creating the search history information, the process is terminated.

  As described above, points that do not require background search are memorized at any time, and by executing background search automatically when passing the point again, excessive background search can be executed. Can be suppressed. In the above description, the alternative station search is performed in the background. However, in some embodiments, the background search function is not provided, and the alternative station search is performed using all tuners as in the all station scan. The present invention can be applied to anything.

  In addition, when performing point collation by the history information collation unit, a predetermined range as shown in FIG. 10 may be provided. A in FIG. 10 is a point where the history information is created. For example, a predetermined section with a radius of several hundred meters may be provided from this point A, and this predetermined section may be set as a prohibited area for prohibiting all-station scanning and alternative station search. By setting the prohibited area in this way, for example, when the next run, even when reception sensitivity deteriorates at a Y point located in the prohibited area, searching for a broadcast station can be prohibited.

  In the above embodiment, it is first determined whether or not terrestrial digital broadcasting is being viewed. However, by providing a prohibited area, it is also applicable when viewing is started after passing a stored point. It becomes possible. For example, in FIG. 10, when viewing starts at the Z point in the prohibited area after passing through the X point, the search for the broadcast station is prohibited from the point Z to the end point of the prohibited area even if the reception sensitivity decreases. Like that. As a result, the present invention can be applied even in a situation where a broadcast wave is received after passing through a stored point. In addition to the prohibited area, the search for the broadcasting station may be prohibited within a predetermined time from the point stored in the history information.

  In addition, although the history information described above has been used to determine locations where the host vehicle has traveled in the past and store locations that satisfy the conditions, the history information stored by other vehicles is acquired using inter-vehicle communication or the like. The search for a broadcast station may be prohibited when the host vehicle passes through a point stored in the history information. As a result, it is not necessary to create history information again even on a road that travels for the first time, and the search for broadcasting stations can be prohibited from the beginning.

  In the above-described embodiment, the passing direction of the spot is stored, and the history information matching unit 320 also performs matching based on the passing direction. However, the storing and checking of the passing direction may not be performed depending on the embodiment. When the passage direction is not taken into consideration, the broadcast station search prohibition control may be performed with the passage of a point stored in the history information as a trigger, or the above-described prohibited area may be provided.

  By performing the above processing, it is possible to detect the location of the vehicle without lowering the GPS signal, but search for broadcasting stations such as unnecessary all-station scan and alternative station search in locations where broadcast reception sensitivity is reduced. The broadcast wave can be received as soon as reception becomes possible. Thereby, it becomes possible to suppress the search for excessive broadcasting stations and to increase the viewing time.

  Although the preferred embodiment of the present invention has been described in detail, the present invention is not limited to the specific embodiment, and various modifications and changes can be made within the scope of the gist of the invention described in the claims. Is possible.

DESCRIPTION OF SYMBOLS 1 Own vehicle 2 Broadcast station 3 Artificial satellite 4 Tunnel 5 Building A Start point B of unreceivable area End point C of unreceivable area All station scan completion points 171 and 171a to 171d Antenna 231 Display

Claims (10)

An electronic device equipped with a receiving function of a broadcasting station mounted on a mobile body,
Receiving means for receiving broadcast waves broadcast from a broadcasting station;
Detecting means for detecting the reception sensitivity of the broadcast wave received by the receiving means;
Obtaining means for obtaining position information of the moving body;
In response to a decrease in the detected reception sensitivity, search means for causing the reception means to search for a selectable broadcast station,
Storage means for acquiring position information at the point where the reception sensitivity is reduced from the acquisition unit, and storing search history information including the point and a search result;
An electronic device comprising: search control means for controlling the search means based on the search history information. The search result includes information that the channel of the broadcast station before performing the search and the channel of the broadcast station after performing the search are the same, and the search control means includes the position information of the mobile object The electronic device according to claim 1, wherein, when a stored point is applicable, search for a broadcasting station by the search means is prohibited. The search result includes information that the search is interrupted by the user, and the search control means broadcasts the search means when the position information of the mobile object corresponds to the stored point. The electronic device according to claim 1, wherein search for a station is prohibited. The electronic device according to claim 1, wherein the search unit causes the reception unit to search for all broadcast stations from a minimum frequency to a maximum frequency. The search control means prohibits a search for a broadcasting station by the search means when the position information of the mobile object is within a predetermined range of the stored point. The electronic device as described in any one. 5. The search control unit according to claim 1, wherein the search unit prohibits a search for a broadcasting station by the search unit for a predetermined time after the moving body passes the stored point. 6. Electronic devices. The search history information further includes a traveling direction of the moving body, and the search control means is configured to use the searching means when the position information and the traveling direction of the moving body correspond to the point and the traveling direction of the search history information. The electronic device according to claim 1, wherein search for a broadcasting station is prohibited. The receiving means is capable of receiving a plurality of broadcast waves,
The electronic device according to claim 1, wherein the searching unit causes the receiving unit to search for another broadcasting station while the receiving unit is receiving one broadcasting station. The electronic device according to claim 8, wherein the search unit searches for all broadcast stations when a search for a relay station or an affiliated station by the reception unit fails. An automatic channel selection method having a receiving function of a broadcasting station mounted on a mobile body,
Get the location information of the moving object,
Detect the reception sensitivity of the broadcast wave broadcast from the receiving broadcast station,
In response to a decrease in reception sensitivity, search for a broadcastable station,
Obtain location information at a point where reception sensitivity has decreased, store search history information including the point and search results,
An automatic channel selection method for controlling whether or not a searchable broadcast station is searched based on search history information.

Images