JP5787788B2 - Reception device, broadcast station display method, and display program - Google Patents

Description

  The present invention relates to a receiving apparatus mounted on a vehicle such as a moving body, and more particularly to a radio receiving apparatus capable of receiving a broadcast signal in which data is multiplexed.

  In Europe and the like, a radio data system (Radio Data System, hereinafter referred to as RDS) in which various types of data are multiplexed on a radio broadcast signal is put into practical use. The multiplexed data includes information identifying a broadcast program (PI: Program Identification), information identifying a program genre (PTY: Program Type), alternative broadcasting stations, and road traffic information by a TMC (Traffic message Channel) service. Etc. are included. When the radio receiver installed in a vehicle changes its reception sensitivity with the movement of the vehicle, and the reception sensitivity of the broadcasting station currently being watched deteriorates, it switches to an alternative broadcasting station or another broadcasting station. Is required. In general, a list of alternative broadcast stations or other receivable broadcast stations (station list) having the same PI code as the currently viewed broadcast station is displayed on the display, and the user can select a broadcast station from the list. Can be selected.

  The list of broadcast stations is updated by performing a full scan of the frequency band. However, if it takes time to acquire road traffic information by the TMC service, the update frequency becomes slow. Therefore, a radio receiver that acquires status information indicating the status of the in-vehicle device from the in-vehicle device and sets whether to update the list of broadcast stations based on the status information or provide road traffic information to the in-vehicle device has been proposed. (Patent Document 1).

JP 2011-19041 A

  In the RDS receiver, updating the list of broadcast stations requires a certain amount of time for scanning in order to confirm the existence of frequencies that can be received in units of 100 KHz over the entire frequency band. This scanning time is proportional to the number of receivable frequencies. If there are 20 receivable frequencies, about 2 minutes are required to scan one frequency band. This means that the information acquired by the broadcast station in the broadcast station list two minutes ago is reflected. In other words, the update cycle of the reception status of the broadcast station takes about two minutes at the maximum. For this reason, a broadcast station that was receivable two minutes ago may no longer be receivable, and on the contrary, a broadcast station that is not receivable two minutes ago is now receivable. Sometimes. In particular, if you are traveling in an area where the reception situation is abruptly deteriorated, such as tunnels and underground parking lots, there is a large change in the broadcast stations that can be received and those that are not, so the list of broadcast stations is updated as soon as possible. It is desirable.

  The present invention solves such a conventional problem, and provides a receiving apparatus, a broadcasting station display method, and a display program capable of promptly providing users with update information of receivable broadcasting stations. With the goal.

  A receiving apparatus according to the present invention is capable of receiving a broadcast signal in which data is multiplexed, and is received by at least first and second receiving means capable of receiving a broadcast signal and the first receiving means. While outputting the broadcast signal, the second receiving means scans the frequency band, and the data is extracted from the broadcast signal received during the scanning period by the scanning means. Extraction means, holding means for holding a frequency table registered with receivable frequencies in the frequency band scanned by the scanning means, and a display for displaying a broadcasting station corresponding to the frequency table held by the holding means Determining means for determining whether or not the frequency in the frequency table is receivable during a period in which the scanning of the frequency band is performed by the scanning means; An update unit that updates the display of the broadcast station by the display unit based on the determination result of the determination unit, and a mode that determines that it is a reception difficulty mode that travels in an area where reception is difficult based on the reception state of the broadcast signal And when the mode determining unit determines that the mode is difficult to receive, the determining unit sets a period for determining whether or not the frequency is receivable when the mode is other than the difficult to receive mode. Shorter than.

  Preferably, the mode determination unit determines that the mode is a reception difficulty mode when the number of broadcast stations displayed by the display unit is decreased under the first condition. Preferably, when the number of broadcast stations displayed by the display unit increases under the second condition, the mode determination unit determines that the reception difficulty mode is canceled and is the normal mode, and the determination unit When it is determined that the mode is selected, the cycle for determining whether or not the frequency can be received is returned to the original cycle. Preferably, the extraction unit stops extracting predetermined data from the broadcast signal when it is determined that the reception difficulty mode is set. Preferably, the first condition is that the number of broadcasting stations decreases at a constant rate within a predetermined period. Preferably, the second condition is that the number of broadcasting stations increases at a constant rate within a predetermined period. Preferably, while the scanning unit performs scanning from the lower limit to the upper limit of the frequency band or from the upper limit to the lower limit, the determination unit determines whether or not each frequency in the frequency table is receivable by time division. To do. Preferably, the determination means includes means for setting a flag in the frequency table when it is determined that the predetermined frequency is not receivable, and the update means updates the display of the broadcast station based on the set flag. . Preferably, the receiving apparatus further controls selection by the first receiving unit based on a selection unit that selects a broadcasting station from the list of broadcasting stations displayed by the display unit, and the broadcasting station selected by the selection unit. Control means. For example, the area where the reception is difficult is a tunnel or underground. Preferably, the first and second receiving means receive an RDS broadcast. Preferably, the first and second receiving means receive a digital broadcast.

  The broadcast station display method according to the present invention is in a receiving apparatus capable of receiving a broadcast signal in which data is multiplexed, and while the broadcast signal received by the first receiving means is being output, A step of scanning a frequency band by a second receiving means; a step of extracting data from a broadcast signal received during a period during which the scanning means is scanning; and the frequency band scanned by the scanning means A step of holding a frequency table in which receivable frequencies are registered, a step of displaying a broadcasting station corresponding to the frequency table held by the holding unit, and a period during which scanning of the frequency band is performed Determining whether the frequency in the frequency table is receivable and determining whether the frequency is receivable based on the determination result Updating the display; determining based on the reception state of the broadcast signal; determining that it is a reception difficulty mode traveling in an area where reception is difficult; and determining that the reception difficulty mode is selected, the frequency is And a step of shortening a cycle for determining whether or not reception is possible, as compared with a mode other than the non-reception difficult mode.

  The broadcast station display program according to the present invention is executed by a receiving apparatus capable of receiving a broadcast signal in which data is multiplexed, and while the broadcast signal received by the first receiving means is being output. A step of scanning a frequency band by a second receiving unit; a step of extracting data from a broadcast signal received during a period during which the scanning unit is scanning; and the step of scanning by the scanning unit A step of holding a frequency table in which receivable frequencies within a frequency band are registered, a step of displaying a broadcasting station corresponding to the frequency table held by the holding means, and a period during which the frequency band is scanned And determining whether or not the frequency in the frequency table is receivable and determining whether or not the frequency is receivable. A step of updating the display of the broadcast station, a step of determining that it is a reception difficulty mode traveling in an area where reception is difficult based on a reception state of the broadcast signal, and a case where it is determined that it is the reception difficulty mode And a step of shortening a cycle for determining whether or not the frequency is receivable as compared with a mode other than the mode in which the reception is difficult.

  According to the present invention, when it is determined that the mode is difficult to receive, the cycle for determining whether or not the frequency is receivable is performed at a high speed. Possible broadcast stations can be displayed immediately. This provides the user with the latest reliable indication of receivable broadcast stations and reduces the probability that the user will not be able to receive the broadcast station when the user selects the broadcast station. can do.

FIG. 1A is a diagram illustrating an example of an in-vehicle electronic system according to an embodiment of the present invention, and FIG. 1B is a block diagram illustrating a configuration of a radio receiving apparatus according to the embodiment of the present invention. It is a block diagram which shows a part of function contained in the control part shown to FIG. 1 (B). It is an example of the frequency table which registered the frequency which can be received. It is an example of the alternative frequency table which prescribed | regulated the relationship between PI code and an alternative frequency. It is a display example of a broadcast station list. It is an example of the frequency table containing a reception determination flag. It is a graph explaining the process performed by the scan at the time of normal mode in the radio receiver which concerns on the Example of this invention. It is a graph explaining the process performed by the scanning at the time of the reception difficult mode in the radio receiver which concerns on the Example of this invention. It is a flow explaining the production | generation operation | movement of the frequency table in the radio receiver which concerns on the Example of this invention. 5 is a flow for determining whether or not a frequency can be received in the radio reception apparatus according to the embodiment of the present invention. It is a flow explaining the production | generation operation | movement of the broadcast station list which concerns on the Example of this invention. It is a flow explaining the update operation | movement of the broadcast station list which concerns on the Example of this invention. It is a flow explaining the determination operation | movement of the reception difficulty mode which concerns on the Example of this invention. It is a figure which shows the example of an update of the broadcast station list | wrist by the Example of this invention.

  Next, embodiments of the present invention will be described with reference to the drawings. A preferred embodiment of the present invention exemplifies a radio receiving device mounted on an automobile as a moving body. In addition, the radio reception apparatus can receive a radio broadcast in which data is multiplexed. Here, as an example, the radio reception apparatus receives an RDS broadcast.

  FIG. 1A is a diagram illustrating a configuration of an in-vehicle electronic system according to an embodiment of the present invention. The on-vehicle electronic system 10 includes a radio receiver 20 mounted on a vehicle and a navigation device 30. The radio receiver 20 receives a radio broadcast selected by the user, and road traffic information included in data superimposed on the radio broadcast is provided to the navigation device 30. In RDS broadcasting, digital data (RDS data) is superimposed on an analog FM broadcast signal. This RDS data includes a PI code for identifying a broadcast program, a broadcast service name (broadcast station), a broadcast program genre, and a TMC service. Includes road traffic information.

  The road traffic information acquired by the radio receiver 20 is provided to the navigation device 30. The navigation device 30 can display the acquired road traffic information on a road map or use it for voice guidance. An in-vehicle electronic system 10 shown in FIG. 1A represents one configuration example, and includes a television receiver, a DVD / Blu-ray disc playback device, a multi-function terminal (smartphone), and the like. It may also have only a radio receiver.

  FIG. 1B is a block diagram illustrating a configuration of the radio receiving apparatus according to the present embodiment. The radio receiver 20 includes a first tuner 110A, a second antenna 100B, and a second antenna that receive a broadcast signal of a frequency (broadcast station) selected via the first antenna 100A and the first antenna 100A. Receives reception signals from the first tuner 110B and the first and second tuners 110A and 110B that receive a broadcast signal of a selected frequency (broadcast station) via 100B, and performs necessary processing on each reception signal. The signal processing unit 120, the amplifier 130 that amplifies the audio signal processed by the signal processing unit 120, the speaker 132 that outputs the audio signal amplified by the amplifier 130, the data decoded by the signal processing unit 120, and the like can be displayed Display unit 140, storage unit 150, input unit 160 that receives input from the user, navigation device 30 includes an interface (I / F) unit 170 that enables connection with an external device such as 30, first and second tuners 110 </ b> A and 110 </ b> B, a signal processing unit 120, an amplifier 130, and the like. Is done.

  As is known, the first tuner 110A receives an RF signal from the first antenna 100A, an RF amplifier that amplifies the RF signal, a tuning circuit that selects a frequency signal of a desired station from the amplified RF signal, and a local oscillator A mixer that generates an intermediate frequency (IF) signal by mixing the frequency signal from the RF signal and an RF signal, and an S meter circuit that DC-detects the intermediate frequency signal and extracts a received electric field strength signal (S meter signal). . However, the reception sensitivity may be determined using a C / N value (Carrier to noise) in addition to the electric field strength signal. Further, the first tuner 110 </ b> A converts the intermediate frequency signal (IF) and the S meter signal into digital signals by an ADC (analog / digital converter), and outputs them to the signal processing unit 120 and the control unit 180. The second tuner 110B is also configured similarly to the first tuner 110A. The first and second tuners 110A and 110B can select the same frequency or different frequencies in accordance with an instruction from the control unit 180. In the preferred embodiment of this embodiment, the first tuner 110A uses the first and second tuners 110A and 110B. When a radio broadcast is being viewed, the second tuner 110B scans the frequency band by a background operation, and checks for receivable frequencies and extracts RDS data.

  The signal processing unit 120 is configured using, for example, a DSP (Digital Signal Processor). The signal processing unit 120 can perform signal processing such as FFT, digital filtering, signal synchronization, time / frequency deinterleaving, audio decoding, data decoding, and phase diversity. These signal processes can be controlled using software stored in a program memory in the signal processing unit 120. In a preferred embodiment, the signal processing unit 120 includes a DAC (digital / analog converter), extracts the audio signal from the digital signal received from the first tuner 110A, converts this into an analog signal, and outputs the audio signal. To the amplifier 130. Further, the signal processing unit 120 extracts RDS data from the signal received from the second tuner 110B, and enables various processes on the RDS data. For example, a PI code, a program service name (PS), road traffic information, and the like are extracted from the RDS data and provided to the control unit 180.

  The control unit 180 is composed of, for example, a microcontroller and controls each unit by executing a program stored in a memory. In a preferred operation mode, the control unit 180 causes the second tuner to scan the frequency band by background processing while the first tuner 110A receives the radio broadcast, and the RDS data is transmitted via the signal processing unit 120. To get.

  FIG. 2 shows functional blocks of the control unit 180 of this embodiment. In the figure, a control unit 180 signals a frequency scanning unit 200 that causes the second tuner 110B to scan the entire frequency band at a constant frequency interval during background processing, and RDS data extracted when the frequency band is scanned. The RDS data acquisition unit 202 acquired via the processing unit 120, the PI code extraction unit 204 that extracts the PI code from the acquired RDS data, and the frequency that makes the PI code the same based on the extracted PI code are registered. An alternative broadcast station creation unit 206 that creates an alternative frequency table, an alternative broadcast station holding unit 208 that holds the created alternative frequency table, and a field strength signal received when scanning the frequency band is a threshold. A frequency table that discriminates frequencies that are equal to or greater than the value and creates a frequency table that registers such receivable frequencies. A creation unit 210; a frequency table holding unit 212 that holds the created frequency table; a broadcast station display unit 214 that displays a list of receivable broadcast stations based on the frequency table held in the frequency table holding unit 212; A list of broadcast stations based on a reception sensitivity determination unit 216 that individually determines whether or not a frequency in the frequency table is receivable during a period of scanning the frequency band, and a determination result of the reception sensitivity determination unit 216. Display update unit 218 and mode determination unit 220 that determines whether or not it is a reception difficulty mode for traveling in an area where radio wave reception is difficult.

  While the first tuner 110A is listening to the radio broadcast, the frequency scanning unit 200 sets the frequency band predetermined by the second tuner 110B from the upper limit to the lower limit or from the lower limit to the upper limit at regular frequency intervals. Scan and check for receivable frequencies. Whether or not the frequency is receivable is determined by comparing the electric field strength signal from second tuner 110B with a threshold value, and if the electric field strength signal is equal to or greater than the threshold value, it is determined that reception is possible. . The scanning result of the frequency scanning unit 200 is sequentially provided to the frequency table creation unit 210.

  When a receivable frequency is detected by the frequency scanning unit 200, RDS data multiplexed on the broadcast signal of the frequency is extracted by the signal processing unit 120, and the extracted RDS data is provided to the RDS data acquisition unit 202. The The PI code extraction unit 204 extracts a PI code that is program identification information of the frequency currently received from the RDS data. The extracted PI code is provided to the frequency table creation unit 210.

  The frequency table creation unit 210 receives the frequency that can be received by the frequency scanning unit 200 and the PI code extracted by the PI code extraction unit 204, and creates a frequency table in which the frequency and the PI code are paired. When receiving European FM broadcasting, the second tuner 110B scans the frequency band from 108.0 MHz to 87.5 MHz at an interval of 100 KHz, and the receivable frequency is determined therefrom. FIG. 3 is an example of a frequency table in which frequencies determined to be receivable are registered. In the frequency table, a relationship between a receivable frequency and a PI code corresponding to the frequency is defined. The frequency table is updated so that a receivable broadcast station is found every time a receivable broadcast station is found during scanning of all frequency bands. In this embodiment, as described later, During the scanning period, the reception sensitivity of each frequency registered in the frequency table is determined, and the determination result is reflected in the frequency table as needed.

  The alternative broadcast station creation unit 206 creates an alternative frequency table based on the PI code extracted by the PI code extraction unit 204. The alternative frequency table is a table in which frequencies having the same PI code are registered. In other words, the alternative frequency table is a table for identifying a broadcast station that distributes the same broadcast program as the currently received broadcast station. FIG. 4 shows an example of the alternative frequency table. For example, in the alternative frequency table 222, the current frequency is 98.5 MHz and its PI code is D303 (see FIG. 3). Alternative frequencies having D303 as the PI code are 92.3 MHz, 94.3 MHz, 99.7 MHz, and 107.5 MHz represented by AF (1) to AF (4). In the alternative frequency table 222, “BAYERN 3” is registered as the program service name (PS). Such an alternative frequency table is created for at least the frequencies included in the frequency table shown in FIG.

  The broadcast station display unit 214 refers to the PS of the frequency table and the alternative frequency table, and displays a broadcast station list corresponding to receivable frequencies. Specifically, the corresponding alternative frequency table (FIG. 4) is searched based on the PI code corresponding to the frequency shown in FIG. 3, and the program service name PS is extracted therefrom. When a plurality of frequencies have the same PI code, since the broadcasting stations are common, one broadcasting station is displayed for the plurality of frequencies. FIG. 5 is a display example of a broadcast station list. In this broadcast station list, a list 230 of program service names of frequencies that can be received is displayed in a column 230 that displays the name of a program service (or broadcast station) that is currently received, and a list column 240 below the column 230. In the list column 240, an identification display 242 is attached to the broadcast program currently being received. The broadcast station list may also display broadcast program genres and frequencies as information other than the program service name.

  The reception sensitivity determination unit 216 determines whether or not the frequencies included in the frequency table shown in FIG. 3 can be received. Although details of this determination method will be described later, it should be noted that the determination is performed in a time division manner during scanning of the entire frequency band by the frequency scanning unit 200. The determination result of the reception sensitivity determination unit 216 is provided to the display update unit 218, and the display update unit 218 updates the broadcast station list to the latest reception state. As a preferred example, the determination result of the reception sensitivity determination unit 216 is represented using a reception determination flag associated with a frequency table as shown in FIG. The flag “1” indicates a state where reception is possible, and the flag “0” indicates a state where reception is not possible. When the reception determination flag is changed to “0”, the broadcast station updating unit 218 deletes the broadcast station corresponding to the frequency from the broadcast station list illustrated in FIG. 5, and conversely, the reception determination flag is “1”. When the change is made, the broadcast station corresponding to the frequency is added to the broadcast station list shown in FIG.

  The mode determination unit 220 determines whether the vehicle is in a reception difficulty mode in which the vehicle travels in an area where radio wave reception is difficult, such as a tunnel or an underground parking lot. The judgment method is to monitor the number of broadcasting stations displayed in the broadcasting station list, and when the number of broadcasting stations has decreased by a certain percentage or a certain number within a certain time, the mode has shifted from the normal mode to the reception difficulty mode. Is determined. For example, it is a case where the number of broadcasting stations decreases by 70% or more within 60 seconds. This condition can be set arbitrarily. Further, when in the reception difficulty mode, it is determined that the reception difficulty mode has been left when the number of broadcasting stations increases by a certain ratio or a certain number within a certain time. For example, this is a case where the number of broadcasting stations has increased by 70% or more within 60 seconds, and this condition can be set arbitrarily. The mode determination unit 220 determines whether or not the reception difficult mode is based on the increase / decrease in the number of broadcast stations. The number of broadcast stations is based on the receivable frequency after all, and the receivable frequency. This is substantially synonymous with the determination based on the increase / decrease in the number of. Furthermore, the mode determination unit 220 may determine whether or not it is a reception difficulty mode for traveling in an area where reception is difficult based on the reception state of the broadcast signal. Specifically, the mode determination unit 220 determines whether or not the broadcast signal is difficult to receive based on the degree of change in the reception state of the broadcast signal being received (the output level of the S meter). judge. When the traveling vehicle is out of the reception area of the broadcasting station, the output level of the S meter gradually decreases. However, when the vehicle enters a tunnel or a parking lot in the building, the output level of the S meter suddenly increases. Decrease. Therefore, it can be determined that a so-called reception difficulty mode has been entered in which a tunnel or the like has been entered when the rate of decrease in the output level of the S meter exceeds a predetermined reference value.

  The determination result by the mode determination unit 220 is provided to the frequency scanning unit 200, the PI code extraction unit 204, the frequency table holding unit 212, the reception sensitivity determination unit 216, and the like, and an operation corresponding to the difficult reception mode is performed. In a preferred embodiment, when the mode is shifted to the reception difficulty mode, the frequency scanning unit 200 suspends searching for a newly receivable frequency in the scanning of the frequency band, and the signal processing unit 120 suspends the extraction of RDS data. To do. Instead, the reception sensitivity determination unit 216 determines whether or not the frequency table can be received more frequently than in the normal mode. That is, the frequency determination period for determining whether or not the frequency can be received in the normal mode is increased by n times in the difficult reception mode. For example, in the normal mode, what is determined whether or not the frequency can be received is determined every second, and in the difficult reception mode, whether or not the frequency can be received is determined every 2 msec. Thereby, the update speed of the reception determination flag is increased, and as a result, the update speed of the broadcast station list by the display update unit 218 is also increased. Further, when the frequency table holding unit 212 is determined to be in the reception difficulty mode, the frequency table storage unit 212 stores the frequency before entering the reception difficulty mode in the memory, and the reception sensitivity determination unit 216 determines that reception is not possible. Does not delete the frequency from the frequency table.

Next, the operation of the radio receiving apparatus according to the embodiment of the present invention will be described. FIG. 7 is a graph for explaining processing when the second tuner 110B operated in the background scans the frequency band in the normal mode. The vertical axis is frequency, and the horizontal axis is time. The upper limit of the frequency band is 108.0 MHz, the lower limit is 87.5 MHz, and an example in which scanning from the upper limit to the lower limit is performed once is schematically shown. Process A is extraction of RDS data from the RDS broadcast station, process C is determination of reception sensitivity of frequencies registered in the frequency table, and process B is extraction of road traffic information from the TMC broadcast station. .

  When scanning by the frequency scanning unit 200 is started and it is determined that the frequency f2 can be received, a broadcast signal of the RDS broadcast station is received, and processing A for extracting RDS data from the broadcast signal is performed. The RDS data includes, for example, a PI code, information for identifying a program genre (PTY), a program service name (PS), a traffic program identification (TP), and the like. When the process A ends, a process B for acquiring road traffic information (TMC data) at the frequency f5 is then executed. Since the TMC data is transmitted from the TMC broadcast station at a constant cycle, the radio reception apparatus acquires the TMC data in synchronization with the TMC data. Next, when it is determined that the frequency f3 can be received, a process A for extracting RDS data is executed, and then a process C for determining whether or not the frequency registered in the frequency table can be received is performed. It is arbitrary from which frequency in the frequency table the determination is started. For example, if scanning is performed in order from the highest frequency, reception sensitivity is checked from the highest frequency in the frequency table. Here, an example is shown in which the electric field strength is checked to determine whether or not reception is possible for the frequencies f1, f2, f4, f7, f8, f11, and f14 registered in the frequency table. The process C is performed in a time-division manner at a constant cycle in parallel with the frequency band scanning by the frequency scanning unit 200.

  Thereafter, similarly, processing A to processing C are executed, and when one scan of all frequency bands is completed, a frequency table as shown in FIG. 3 or FIG. 6 is completed. If there are many receivable frequencies in the frequency band, the time required for one scan becomes long. For example, if there are about 20 receivable frequencies, one scan requires about 2 minutes. When the first scan is completed, the second scan is started by the second tuner 110B.

  FIG. 8 is a flowchart for explaining the operation of creating a frequency table by the frequency scanning unit. The frequency of the second tuner 110B is changed in units of 100 KHz by the frequency scanning unit 200 (S101), and the electric field strength signal of the frequency received by the second tuner 110B is provided to the control unit 180 (S102). The control unit 180 determines whether or not the electric field strength signal is equal to or higher than the threshold value (S103). If the electric field strength signal is equal to or higher than the threshold value, the control unit 180 determines that the frequency is receivable (S104). It is determined whether or not the frequency broadcast station is an RDS broadcast station (S105). If it is an RDS broadcasting station, as shown in FIG. 7, RDS data is extracted in process A (S106), and the frequency and PI code are registered in the frequency table (S107). When the frequency reaches the upper limit or lower limit frequency of the frequency band (S108), the scanning is finished and the next scanning is started again.

  FIG. 9 is a flow of process C for determining whether or not the frequency table can be received. The reception sensitivity determination unit 216 selects one frequency from a plurality of frequencies registered in the frequency table (S201), and the second tuner 110B is tuned to the selected frequency. The reception sensitivity determination unit 216 receives the electric field strength signal of the selected frequency (S202), and checks whether the electric field strength signal is equal to or higher than a threshold value (S203). If the field strength signal is equal to or greater than the threshold value, it is determined that the frequency is receivable (S204), and if the corresponding reception determination flag is “0”, it is changed to “1” ( S205, S206). On the other hand, if the electric field strength signal is less than the threshold value, it is determined that the frequency cannot be received (S207), and if the reception determination flag is “1”, this is changed to “0” (S208, S209). Whether or not reception is possible for one frequency is determined, and if an undetermined frequency registered in the frequency table remains (S210), the next frequency is selected, and if no undetermined frequency remains, the process ends. The process C for determining the reception sensitivity of the frequency registered in the frequency table is executed in a time division process in parallel with the scanning of the frequency band by the frequency scanning unit 200.

  Next, the broadcast station list creation operation is shown in the flow of FIG. The broadcast station display unit 214 refers to the frequency table created by the frequency table creation unit 210 (S301), and the program service name searched based on the frequency for which the reception determination flag is “1” and the PI code of the frequency ( PS) is acquired (S302). Next, as shown in FIG. 5, the broadcast station display unit 214 creates a list of broadcast station names of the currently received frequency and other receivable broadcast station names (S303), and displays this list. (S304).

  FIG. 11 is a flow for updating the display of the broadcast station list. The broadcast station list is displayed by the broadcast station display unit 214 (S401), and then the display update unit 218 monitors the reception determination flag in the frequency table shown in FIG. 6 and checks whether or not the flag has been changed (S402). ). When the flag is changed from “0” to “1” (S403), the display update unit 218 adds the broadcast station corresponding to the frequency with the changed flag to the broadcast station list (S404). On the other hand, when the flag is changed from “1” to “0”, the display update unit 218 deletes the broadcast station corresponding to the frequency with the changed flag from the broadcast station list (S405). The display update unit 218 may update the broadcast station list based on the frequency table without checking whether or not the flag has been changed when one scan of all frequency bands is completed. .

  FIG. 12 is a flowchart illustrating an example of the operation of determining the reception difficulty mode by the mode determination unit. The mode determination unit 220 monitors the number of broadcast stations in the broadcast station list (S501). When the number of broadcast stations decreases (S502), the mode determination unit 220 determines whether the decrease satisfies a certain condition (S503). Preferably, when the number of broadcasting stations suddenly decreases at a certain rate within a certain time, it is considered that the radio wave is difficult to receive, such as a tunnel or an underground parking lot, and the normal mode is changed to the reception difficult mode. It determines with a thing (S504). When the mode determination unit 220 determines the difficult reception mode, the process A for extracting the RDS data is interrupted in the frequency band scanning, and the process B for extracting the TMC data and the availability of the frequency registered in the frequency table are determined. The determination process C is performed, and as a result, the determination cycle of the process C is performed at a speed n times that in the normal mode (S505).

  FIG. 7A is a graph for explaining processing when it is determined that the reception difficult mode is set. As shown in the figure, when it is determined that the mode is difficult to receive, the process A for extracting RDS data performed during scanning in the frequency band is interrupted, and the processes C and TMC data for determining whether or not the frequency can be received are extracted. Process B is continuously performed in a time division manner. In the example shown in the figure, the process C for the frequencies f1, f2, f4, f5, f7, f8, f11, and f14 registered in the frequency table is repeatedly performed. Processing B for extracting data is performed. As described above, in the reception difficulty mode, the process C is executed at a cycle that is much shorter than that in the normal mode. In the process C for determining whether or not reception is possible, even if it is determined that the frequency (for example, the frequency f1) registered in the frequency table is unreceivable, the frequency f1 is retained without being deleted from the frequency table. In the next process C, it is continuously determined whether or not the frequency f1 can be received, and the determination result is set in a flag. Since the frequency registered in the frequency table is held during the reception difficulty mode, it is determined that the frequency stored in the frequency table is receivable when the radio wave reception environment is restored, that is, when the mode is changed to the normal mode. For example, the result is instantly reflected in the broadcast station list.

  Returning to FIG. 12 again, the high-speed reception determination C processing (S505) as shown in FIG. 7A is continued for a period during which it is determined that the reception difficult mode is set. The mode determination unit 220 monitors whether or not the number of broadcast stations in the broadcast station list has increased (S506), and determines whether or not the increase satisfies a certain condition when the number of broadcast stations increases. (S507). Preferably, when the number of broadcasting stations suddenly increases within a certain period of time, it is determined that the reception difficulty mode has been cancelled, assuming that the area where radio wave reception is difficult, such as a tunnel or underground parking lot, has been escaped. The normal mode is entered (S508). When the reception difficulty mode is canceled, as shown in FIG. 7, the processes A to C are returned to the normal process (S509). In the above example, the process A is interrupted and the processes B and C are executed in the reception difficulty mode. However, the processes A and B may be interrupted. Alternatively, only a specific process in the process A may be interrupted. In short, it is possible to arbitrarily set which process is interrupted, and the cycle of process C may be performed at a higher speed than in the normal mode.

  FIG. 13 shows a specific example of updating the broadcast station list. The broadcast station list 300 shows receivable broadcast stations in the normal mode. The number of broadcast stations is 10, but this number does not necessarily match the number of receivable frequencies in the frequency table. When the frequency table includes a frequency where the PI code overlaps, a broadcast station corresponding to the PI code is displayed in the broadcast station list. When the display of the broadcast station list 300 transitions to the display of the broadcast station list 310, the number of broadcast stations is drastically reduced, so that it is determined that the reception difficulty mode. Here, 10 broadcast stations are rapidly reduced to 2 broadcast stations, and only “BAYERN3” and “BAYERN4” can receive broadcast station names or program service names in the tunnel.

  In response to the transition to the reception difficulty mode, the reception sensitivity determination unit 216 determines whether each frequency (87.7 MHz to 107.9 MHz) registered in the frequency table 320 is receivable, The reception determination flag is updated according to the determination result. As described above, in the reception difficulty mode, the update speed to the reception determination flag is higher than that in the normal mode, and the frequency determined to be unreceivable continues to be held without being deleted from the frequency table. . When the frequency that can be received increases rapidly and the determination result is reflected in the flag of the frequency table 330, the broadcast station list 340 is updated. Since the frequency registered in the frequency table remains, the broadcast station list is updated instantaneously. It is determined that the reception difficulty mode has been canceled due to a sudden increase in the number of broadcast stations in the broadcast station list 340, and a transition is made to the normal mode. As soon as it enters the tunnel, the broadcast station list 300 is updated to the broadcast station list 310, broadcast stations that are not receivable are immediately deleted from the broadcast station list, and only receivable broadcast stations are displayed in the broadcast station list. . As soon as the user exits the tunnel, the broadcasting station list 310 is updated to the broadcasting station list 340, and the receivable broadcasting stations are immediately displayed in the broadcasting station list. In this way, the update information indicating that the broadcast station is receivable and the broadcast station that is not receivable is quickly provided to the user.

  The preferred embodiment of the present invention has been described in detail above, but the present invention is not limited to the specific embodiment, and various modifications can be made within the scope of the present invention described in the claims. Deformation / change is possible.

  In the above embodiment, the electric field strength signal is used to determine the frequency or the reception sensitivity of the broadcasting station. However, in addition to this, the error rate of the signal and the presence / absence of multipath may be replaced with the electric field strength signal or together with the electric field strength signal It can be used as a determination condition. Further, in the above-described embodiment, the radio receiving apparatus that receives RDS broadcast is exemplified. However, as long as the data can be multiplexed, the radio receiver is not limited to RDS broadcast but may be other radio broadcast. Moreover, it may be not only analog radio broadcast but also digital radio broadcast such as DAB. Furthermore, in the above embodiment, a radio receiver having two tuners is illustrated, but the number of tuners is not particularly limited, and a single tuner is used in time division for receiving broadcast signals and extracting data. Alternatively, it may have three or more tuners.

10: On-vehicle electronic system 20: Radio receiver 30: Navigation device 100A, 100B: Antennas 110A, 110B: Tuner 120: Signal processing unit 130: Amplifier 132: Speaker 140: Display unit 150: Storage unit 160: Input unit 170: Interface unit 180: Control unit 200: Frequency scanning unit 202: RDS data acquisition unit 204: PI code extraction unit 206: Alternative broadcast station creation unit 208: Alternative broadcast station holding unit 210: Frequency table creation unit 212: Frequency table holding unit 214 : Broadcast station display unit 216: reception sensitivity determination unit 218: display update unit 220: mode determination unit 222: alternative frequency list 300, 310, 340: broadcast station list 320, 330: frequency table

Claims (26)

A receiving device capable of receiving a broadcast signal in which data is multiplexed,
At least first and second receiving means capable of receiving a broadcast signal;
Scanning means for scanning the frequency band by the second receiving means while outputting the broadcast signal received by the first receiving means;
Extraction means for extracting data relating to broadcast programs and data relating to road traffic information from broadcast signals received during a period during which scanning is performed by the scanning means;
Holding means for holding a frequency table that registers receivable frequencies in the frequency band scanned by the scanning means;
Display means for displaying a broadcasting station corresponding to the frequency table held by the holding means;
Determination means for determining whether or not the frequency in the frequency table is receivable during a period in which the scanning of the frequency band is performed by the scanning means;
Updating means for updating the display of the broadcast station by the display means based on the determination result of the determination means;
Mode determination means for determining that it is a reception difficulty mode for traveling in an area where reception is difficult, based on the reception state of the broadcast signal;
The holding unit holds the determination result of the determination unit in the frequency table,
When the mode determining means determines that the mode is difficult to receive, the extracting means interrupts the extraction of data related to the broadcast program, so that the determining means determines whether the frequency is receivable. Is shorter than in a mode other than the reception difficult mode. The said holding | maintenance means hold | maintains, without deleting from the said frequency table, the frequency determined as the reception impossible mode by the said determination means, when it determines with it being a reception difficult mode by the said mode determination means. The receiving device described. The receiving apparatus according to claim 1, wherein the mode determination unit determines that the mode is a reception difficulty mode when the number of broadcast stations displayed by the display unit is reduced under the first condition. The mode determining means determines that the reception difficulty mode is canceled and the normal mode is set when the number of broadcasting stations displayed by the display means increases under the second condition,
The receiving apparatus according to claim 1 or 2, wherein when the determination unit determines that the normal mode is set, the period for determining whether or not the frequency is receivable is returned to the original period. The receiving apparatus according to claim 2, wherein the first condition is that the number of broadcasting stations decreases at a constant rate within a predetermined period. The receiving apparatus according to claim 3, wherein the second condition is that the number of broadcast stations increases at a constant rate within a predetermined period. While the scanning unit performs scanning from the lower limit to the upper limit of the frequency band or from the upper limit to the lower limit, the determination unit determines whether or not each frequency in the frequency table is receivable by time division. The receiving device according to claim 1. The determination means includes means for setting a flag in the frequency table when it is determined that a predetermined frequency is not receivable, and the updating means updates the display of the broadcast station based on the set flag. Item 8. The receiving device according to any one of Items 1 to 7. The receiving device further includes a selection unit that selects a broadcast station from a list of broadcast stations displayed by the display unit;
The receiving device according to claim 1, further comprising a control unit that controls channel selection by the first receiving unit based on the broadcasting station selected by the selecting unit. The receiving apparatus according to claim 1, wherein the area where reception is difficult is a tunnel or underground. The receiving apparatus according to any one of claims 1 to 10, wherein the first and second receiving units receive an RDS broadcast. The receiving apparatus according to any one of claims 1 to 11, wherein the first and second receiving units receive digital broadcasting. A broadcast station display method in a receiving apparatus capable of receiving a broadcast signal in which data is multiplexed,
Scanning the frequency band by the second receiving means while outputting the broadcast signal received by the first receiving means;
Extracting data relating to broadcast programs and data relating to road traffic information from broadcast signals received during a period in which scanning is performed by the scanning means;
Holding a frequency table that registers receivable frequencies in the frequency band scanned by the scanning means;
Displaying a broadcast station corresponding to the frequency table held by the holding means;
Determining whether a frequency in the frequency table is receivable during a period in which the frequency band is being scanned;
Holding the determination result of the determining step in the frequency table;
Updating the display of the broadcast station based on the determination result of whether or not the frequency is receivable;
Determining that it is a reception difficulty mode for traveling in an area where reception is difficult, based on the reception state of the broadcast signal;
When it is determined that the mode is difficult to receive, the period for determining whether or not the frequency is receivable by interrupting the extraction of the data related to the broadcast program from the broadcast signal is greater than that other than when the mode is not difficult. A step to shorten,
Display method. The step of holding the determination result when it is determined that the mode is difficult to receive does not delete the frequency determined to be unreceivable by the determination step without erasing it from the frequency table. Display method described in. The display method according to claim 13, wherein the determining step determines that the reception difficulty mode is set when the number of broadcast stations displayed by the display unit decreases under the first condition. The display method further includes the step of canceling the reception difficulty mode and determining that it is the normal mode when the number of the displayed broadcast stations increases under the second condition;
The display method according to claim 13, further comprising a step of returning a period for determining whether or not a frequency is receivable to an original period when it is determined that the normal mode is set. The display method according to claim 15 , wherein the first condition is that the number of broadcast stations decreases at a constant rate within a predetermined period. The display method according to claim 16 , wherein the second condition is that the number of broadcast stations increases at a constant rate within a predetermined period. The determining step includes a step of setting a flag in the frequency table when it is determined that a predetermined frequency is not receivable, and the updating step updates the display of the broadcasting station based on the set flag. The display method according to any one of claims 13 to 18. A broadcast station display program executed by a receiving device capable of receiving a broadcast signal in which data is multiplexed,
Scanning the frequency band by the second receiving means while outputting the broadcast signal received by the first receiving means;
Extracting data relating to broadcast programs and data relating to road traffic information from broadcast signals received during a period in which scanning is performed by the scanning means;
Holding a frequency table that registers receivable frequencies in the frequency band scanned by the scanning means;
Displaying a broadcast station corresponding to the frequency table held by the holding means;
Determining whether a frequency in the frequency table is receivable during a period in which the frequency band is being scanned;
Holding the determination result of the determining step in the frequency table;
Updating the display of the broadcast station based on the determination result of whether or not the frequency is receivable;
Determining that it is a reception difficulty mode for traveling in an area where reception is difficult, based on the reception state of the broadcast signal;
When it is determined that the mode is difficult to receive, the period for determining whether or not the frequency is receivable by interrupting the extraction of the data related to the broadcast program from the broadcast signal is greater than when the mode is other than the mode that is difficult to receive. A step to shorten,
Display program. 21. When it is determined that the reception difficulty mode is set, the step of holding the determination result holds the frequency determined to be unreceivable by the determination step without deleting it from the frequency table. Display program described in. 21. The display program according to claim 20, wherein the determining step determines that the reception difficulty mode is set when the number of broadcast stations displayed by the display unit decreases under the first condition. The display program further cancels the reception difficulty mode when the number of the displayed broadcast stations increases under the second condition, and determines that it is the normal mode;
The display program according to claim 20 or 21, further comprising a step of returning a period for determining whether or not a frequency is receivable to an original period when it is determined that the normal mode is selected. The display program according to claim 22 , wherein the first condition is that the number of broadcasting stations decreases at a constant rate within a predetermined period. The display program according to claim 23 , wherein the second condition is that the number of broadcast stations increases at a constant rate within a predetermined period. The determining step includes a step of setting a flag in the frequency table when it is determined that a predetermined frequency is not receivable, and the updating step updates the display of the broadcasting station based on the set flag. The display program according to any one of claims 20 to 25.

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