JP2007174445A - Method and apparatus for automatically adjusting fm audio output frequency - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and apparatus for automatically adjusting an FM audio output frequency by which a transmission/reception signal due to FM signals of audio signals of various devices can automatically be changed into a frequency with no interference through inexpensive and simple techniques without changing a circuit configuration of a head unit or the like comprising an FM radio. <P>SOLUTION: From a transmission part 6 of an FM signal transmitting/receiving function section 1 functioning as an FM modulator and an FM transmitter, audio signals of various devices are transmitted to an FM radio 2 as FM audio signals and output from a speaker 24 of an audio system. The FM signal transmitting/receiving function section 1 comprises a reception part 7 for receiving an FM broadcast, interference is detected by an interference detection part 9 and a proper transmission frequency is detected so as not to receive any broadcast while there is no transmission from the transmission part 6. The detected frequency is guided for a user and when the user confirms it, setting of a transmission frequency is changed into that frequency. The user manually changes simplified frequency setting for FM audio reception of the FM radio thereafter. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an FM audio output device used for an audio output device such as an FM modulator, an FM transmitter, and a navigation device incorporating these functions, and an FM broadcast in which the output frequency of audio output as an FM signal can be received in the surroundings. The present invention relates to an FM audio output frequency automatic adjustment method that automatically prevents interference due to coincidence with a frequency, and an apparatus that implements the method.

  For example, an audio device for a vehicle includes a head unit that processes audio output signals of various audio devices mounted on the vehicle and outputs them to a speaker. The head unit includes a radio and a CD player built in the main body. In addition to audio equipment such as an MD player, various audio players such as a DVD player that are required by the user other than the audio equipment provided in the head unit are directly connected by a separate signal line and connected with speakers in the car. Watching is done. When connecting with such a signal line, in addition to the signal line directly connecting the circuits of the on-vehicle equipment, the audio output signal line of the audio equipment brought into the vehicle is also connected to the external input terminal.

  In addition, the head unit of the vehicle audio device as described above is connected to an FM transmitter such as an MP3 player brought into the vehicle by using the function of the FM radio in the usual radio, particularly an MP3 player. A specific frequency is set as a transmission output frequency in the frequency of the receivable range in the FM radio, and an audio signal of an audio device connected to the FM transmitter is output as an FM radio wave of this frequency. It is also received by FM radio that matches the reception frequency, signal-processed in the same way as normal FM broadcast reception, and output from a speaker.

  Also, using an FM modulator by the same method, the output signal of the audio equipment brought into the vehicle is converted to an FM signal of a specific frequency, and then connected to the antenna signal input section of the FM radio via a signal line. It is also received in a synchronized manner and output in the same manner as in ordinary FM broadcasting.

  In these various audio device connection forms, devices that are mounted in advance in the vehicle can be directly connected to the input unit of a predetermined signal processing circuit in the head unit in advance by a signal line. This is not possible with retrofit audio devices or various audio devices that users bring into the car. For this reason, in a device that is installed later in the vehicle and has an FM modulator, an engineer may connect the output signal line of the FM modulator to the antenna signal input section of the FM radio at a car audio equipment store or the like. If it is not built in, it is connected in the same manner using a separate FM modulator.

  Also, when the FM transmitter is built in various devices brought into the car, it is connected wirelessly using FM radio waves, and when it is not built in, the output signal of the audio device connected to the FM transmitter is separately transmitted using the FM transmitter. Are wirelessly connected using FM radio waves.

  As described above, FM modulators and FM transmitters are particularly convenient for connection of retrofit audio devices, and are widely used due to diversification of audio devices. The same applies to the navigation device. In particular, in the later-installed navigation device, in addition to outputting sound from the speaker provided in the navigation device, it is desired to output from the speaker having a good acoustic effect attached to the vehicle. Sometimes. In particular, many recent navigation apparatuses have a DVD player function including a television, and it is desired to output the sound from a speaker attached to the vehicle. Therefore, the FM modulator and FM transmitter as described above are built in the navigation device so that such a request can be easily met. Further, even in the case of a navigation device that does not incorporate these, as described above, an FM modulator or FM transmitter is separately used and connected to the same to output the same.

  As described above, when transmitting and receiving an audio signal using an FM signal, a specific frequency that is not received in an area where the vehicle is normally used is selected, and a transmission frequency in an FM modulator or the like is received. The frequency for FM sound reception set in the one-touch reception key or the like in the FM radio is set to the specific frequency. However, because the vehicle moves at a high speed over a wide range, there is a broadcasting station that broadcasts at that specific frequency when moving to another region even if it moves to another region even if it is a specific frequency that is not received in that region as described above. At that time, the sound output from the speaker of the vehicle is not only output from the sound of the audio device in the vehicle, but also the sound being broadcast by the broadcast station is output, and it is uncomfortable as adjacent noise. May also output simple audio.

  In that case, the user adjusts the reception frequency of FM radio, finds and selects a frequency not receiving the broadcast, and changes the setting of the transmission frequency on the FM audio signal output side such as an FM modulator to that frequency. At the same time, the frequency corresponding to the FM audio signal reception key of the FM radio is changed to that frequency. However, this work is troublesome, and it is not preferable for the safe traveling of the vehicle that the driver performs such an operation especially during the traveling of the vehicle.

As a countermeasure, for example, as disclosed in Japanese Patent Application Laid-Open No. 2003-333004, an FM receiver is provided in an FM modulator to receive radio waves in the surrounding area, and the magnitude of the reception level of each frequency is detected in order, When a frequency with a low reception level is selected and the FM audio signal is transmitted, the frequency information is multiplied by a digital signal and transmitted, and the frequency is automatically set to the frequency for FM audio signal transmission in an FM modulator or the like. Is provided with an FM multiplex decoding unit for extracting frequency information from the received FM audio signal and setting the frequency band as the subsequent FM audio reception frequency.
JP 2003-333004 A

  However, in the above known technique, the FM modulator requires means for multiplying the digital signal related to the new reception frequency, and the head unit including the FM receiver further includes an FM multiplex decoding unit for decoding the digital signal related to the frequency. It is necessary to provide.

  The use of such means particularly requires a change in the circuit configuration of the head unit. For example, when a new navigation device is to be mounted on a vehicle, the head unit itself also includes the FM multiplex decoding unit as described above. It is necessary to change it to a new one, which is not preferable because it requires more cost in addition to the navigation device.

  Therefore, the present invention automatically changes the transmission / reception of audio signals of various devices to a frequency free of interference by an inexpensive and easy method without changing the circuit configuration of a head unit or the like equipped with an FM radio. The main object of the present invention is to provide an FM audio output frequency automatic adjustment method that can be transmitted to and output from the device and a device that implements the method.

  The FM audio output frequency automatic adjustment method according to the present invention transmits a device audio signal as an FM audio signal to an external FM radio by a transmission unit at a predetermined frequency, and the FM audio signal transmitted by the transmission unit is Detects that there is interference with the FM broadcast reception signal received by FM radio, detects that the FM audio signal is not transmitted from the transmission means, receives FM broadcasts in order by the FM broadcast reception means, and received An appropriate transmission frequency, which is a frequency that the FM broadcast reception intensity level is equal to or lower than a predetermined value, is detected, the user is instructed to change and set the transmission frequency to an appropriate transmission frequency, and a confirmation signal for changing the reception frequency setting by the user is input. The transmission frequency of the transmission means is changed.

  An FM audio output frequency automatic adjusting apparatus according to the present invention includes a transmission unit that transmits a device audio signal as an FM audio signal to an external FM radio at a predetermined frequency, a reception unit that receives an FM signal, and the transmission unit. And when the interference is detected by the interference detection means, the FM audio signal is detected by the transmission means when the FM interference signal is detected by the interference detection means. And a reception intensity level of FM broadcasts received in order by the receiving means when the audio signal transmission detecting means detects that no FM audio signal is being transmitted. Reception strength level detection means for detecting whether or not is equal to or less than a predetermined value and the reception strength level detected by the reception strength level detection means. The appropriate transmission frequency detecting means for detecting an appropriate transmission frequency that is a frequency equal to or lower than a predetermined value, and reception that guides the user to change and set the reception frequency when the appropriate transmission frequency is detected by the appropriate transmission frequency detecting means. It is characterized by comprising frequency setting change guidance output means and transmission frequency changing means for changing the transmission frequency of the transmitting means when a confirmation signal for changing the receiving frequency setting by the user is input.

  The FM audio output frequency automatic adjustment device according to the present invention is the FM audio output frequency automatic adjustment device, wherein the interference detection unit is different from the FM signal transmitted by the transmission unit and the FM signal received by the reception unit. It is characterized in that interference is detected when it is present.

  Another FM audio output frequency automatic adjustment device according to the present invention is characterized in that, in the FM audio output frequency automatic adjustment device, the interference detection means detects that a user is interfering with an input signal. To do.

  Another FM audio output frequency automatic adjusting device according to the present invention is characterized in that, in the FM audio output frequency automatic adjusting device, the transmitting means is connected to an FM radio by wire or wirelessly.

  Another FM audio output frequency automatic adjustment device according to the present invention is the FM audio output frequency automatic adjustment device, wherein the FM audio output frequency automatic adjustment device is built in an audio output device.

  Since the present invention is configured as described above, in the functional part of the FM modulator or FM transmitter for outputting the audio signal of various devices as an FM signal, transmitting it to the FM radio, and outputting the sound from the FM radio. Without changing the circuit configuration of the FM radio itself or the head unit equipped with the FM radio function, it is possible to automatically change the transmission / reception of the FM audio signal to a frequency free of interference by an inexpensive and easy method. .

  According to the present invention, without changing the circuit configuration of a head unit or the like equipped with an FM radio, the transmission / reception of audio signals of various devices is automatically changed to a frequency free of interference and transmitted by an inexpensive and easy method. The purpose is to transmit the device audio signal as an FM audio signal to an external FM radio by a transmission means at a predetermined frequency, and the FM audio signal transmitted by the transmission means is received by the FM radio. It detects that there is interference, detects that the FM audio signal is not transmitted from the transmission means, receives FM broadcasts in order by the FM broadcast reception means, and the received intensity level of the received FM broadcast is below a predetermined value The appropriate transmission frequency is detected, the user is instructed to change and set the transmission frequency to the appropriate transmission frequency, and the user inputs a confirmation signal to change the reception frequency setting. When it was achieved by changing the transmission frequency of the transmission unit.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a functional block diagram showing various functional units in the embodiment of the present invention and their mutual relationship. In addition, the function part which performs each function in the figure can also be said to be a means which performs each function. In FIG. 1, it functions as a single FM modulator, functions as a single FM transmitter, functions as an FM modulator or FM transmitter built in a voice output device such as a navigation device or a mobile phone, and is also used as a portable CD or DVD. 1 shows an FM signal transmission / reception function unit 1 that functions as an FM modulator or FM transmitter for incorporating various audio output devices such as MD, MP3 players, and the like. The FM signal transmission / reception function unit 1 transmits an FM signal to an FM radio 2 in the figure by an antenna.

  In the FM signal transmission / reception function unit 1 of FIG. 1, audio signals of the various devices are input to the device audio signal input unit 3. Therefore, when the FM signal transmission / reception function unit is used as the main body of the FM modulator or FM transmitter, the device audio signal input unit 3 is provided with a connection terminal with an external device in this portion, and is connected to the external device by a connection cord. Connect and input the audio signal of the device. When the FM signal transmission / reception function unit 1 is an audio output device such as a navigation device or an FM modulator or FM transmitter built in an audio device such as a portable CD player, an output signal line from the audio output unit of each device is used. Connecting.

  The FM transmission signal creation unit 4 converts the audio signal input to the device audio signal input unit 3 as described above into an FM transmission signal for FM communication and outputs the FM transmission signal to the transmission unit 6. The transmission unit 6 performs FM modulation to a predetermined frequency set by the transmission frequency setting unit 5 and outputs the result from the antenna. The transmission frequency set by the transmission frequency setting unit 5 can be changed as necessary by the transmission frequency change instruction unit 18 as described later.

  The FM signal transmission / reception function unit 1 includes a reception unit 7, and tunes to a predetermined frequency set in the reception frequency setting unit 14 among the FM signals received by the antenna, thereby receiving an FM signal having a predetermined frequency. To do. The FM signal received by the receiving unit 7 is output to the signal comparing unit 8 in the example of FIG. 1, and the signal comparing unit 8 also inputs the audio signal transmitted by the transmitting unit 6 and compares the two signals. .

  In the interference detection unit 9, when the FM signal received by the reception unit 7 and the FM signal transmitted by the transmission unit 6 are different from each other by a predetermined value or more, signals other than the FM signal transmitted by the transmission unit 6 are also received. Thus, it can be detected that there is interference with the FM signal transmitted by the FM broadcast or the same kind of surrounding device. When the interference detection unit 9 detects interference as described above, the interference detection storage unit 10 stores that interference occurs at the current transmission frequency, and then receives frequency change instruction unit as described later. 12, the stored result is made available.

  The interference detection unit 9 can automatically detect interference as described above, but outputs the signal from the speaker 24 of the FM radio 2 while the device including the FM signal transmission / reception function unit 1 is used. When the user feels that the audio is interfering with other broadcast signals, the user manually inputs a signal to that effect by operating a predetermined switch. The detection storage unit can also store that interference occurs at the current transmission frequency.

  In the illustrated embodiment, the audio signal transmission detection unit 11 detects the output state of the audio signal output from the FM transmission signal creation unit 4 to the transmission unit 6, and thereby transmits the FM audio signal from the FM signal transmission / reception function unit 1 to the outside. Detect whether it is outputting. If the audio signal transmission detection unit 11 can detect whether or not an FM audio signal is output from the transmission unit 6 to the outside, the audio signal transmission detection unit 11 can take in a signal from each part in the signal output circuit. .

  In the reception frequency change instructing unit 12, it is checked whether or not information indicating that there is interference is recorded in the interference detection storage unit 10 as described above, and information indicating that there is a message is recorded. Sometimes, when the audio signal transmission detection unit 11 detects that no audio signal is currently being transmitted, all frequencies allocated to FM broadcast stations in Japan stored in the FM broadcast frequency data storage unit 13 Using the data regarding the FM broadcast frequency that may be received, for example, it is possible to instruct the reception frequency to be changed in order from the lowest frequency.

  The FM signal received by the reception unit 7 detects the reception signal strength by the reception intensity level detection unit 15, detects that it is currently interfering as described above, and sequentially transmits FM broadcasts when the FM signal is not transmitted. And the signal intensity of the FM broadcast received there is detected. When the received intensity level detection unit 15 detects an intensity level equal to or higher than a predetermined level, it can be seen that an FM broadcast of that frequency is received, and interference occurs when an FM signal is transmitted at that frequency.

  At that time, the appropriate transmission frequency detection unit 17 determines that it is not preferable to set the frequency as the transmission frequency of the FM signal, and instructs the reception frequency change instruction unit 12 to set the next frequency as the reception frequency. . When the appropriate transmission frequency detection unit 17 detects that the intensity level detected by the reception intensity level detection unit 15 is less than or equal to a predetermined value, it is determined that the frequency is appropriate as the transmission frequency. The detection unit 16 inputs a signal for detecting whether or not the current reception frequency set by the reception frequency setting unit 14 and the current transmission frequency set by the transmission frequency setting unit 5 match. When a signal that has been detected is input, the reception frequency change instruction unit 12 is instructed to change the next reception frequency.

  Although the interference detection unit 9 detects the interference as described above, the reception frequency and the transmission frequency coincide with each other here. For example, the interference is surely detected at the time of the interference detection. It is conceivable that the FM broadcast cannot be received, and it is possible to prevent interference again by such a method.

  As described above, the appropriate transmission frequency detection unit 17 determines that the reception intensity level is less than or equal to a predetermined value at the current reception frequency, and that there is little possibility of interference, and the transmission / reception frequency match detection unit 16 determines the reception frequency and transmission frequency. Is detected, the reception frequency setting change guidance output unit 20 sends a signal to the various display monitor screens or various liquid crystal display units. Indicates that changes will be made. In that case, it can also guide by audio | voice output and can also output combining them suitably.

  When the user receives guidance for changing the frequency by their display or voice, when it is determined that the frequency change by the guidance is preferable, a signal is input to the confirmation signal input unit 19 by pressing a confirmation key or the like. When the transmission frequency change instruction unit 18 detects a transmission frequency that is considered to be appropriate by the appropriate transmission frequency detection unit 17 as described above, the signal is input when the user confirms that the frequency is changed to that frequency. The transmission frequency setting unit 5 is instructed to change the transmission frequency to the frequency detected by the appropriate transmission frequency detection unit 17.

  As a result, the FM signal transmitted thereafter from the transmission unit 6 is transmitted at the frequency detected by the appropriate transmission frequency detection unit 17. On the other hand, when the user is instructed to set the reception frequency, for example, when the audio device such as a navigation device or a CD player using the FM signal transmission / reception function unit 1 is stopped. In such a case, since no signal is input to the confirmation signal input unit 19, the setting change of the transmission frequency as described above is not performed, and the meaningless change of the transmission / reception frequency is not performed.

  On the other hand, when the FM signal transmission / reception function unit 1 is used as a built-in or external FM transmitter, the FM signal from the transmission unit 6 is transmitted from the antenna to the FM radio 2 as a radio wave. On the other hand, when this FM signal transmission / reception function unit 1 is used as an FM modulator, it is directly connected to the antenna input unit of the FM radio 2 by a signal line as shown by a broken line in the figure. An FM signal can be transmitted to the FM radio 2 in a state where various adverse effects are prevented. The FM radio 2 is an FM radio alone, and may be a head unit having an FM radio function in a vehicle audio device, and is a home audio device such as a CD player equipped with an FM receiver. May be.

  Similar to a normal FM radio, the FM radio 2 receives a signal from the antenna at the reception unit 21 and the frequency designated by the reception frequency setting unit 24 or the FM audio reception simple frequency instruction unit 26. Thereby, when the user wants to receive a predetermined FM broadcast station, an instruction is given from the instruction signal input unit 27, and the reception frequency set by the reception frequency setting unit 24 according to the instruction of the reception frequency change instruction unit 25 is set. Then, the receiving unit 21 receives the frequency.

  Further, in the FM audio reception simple frequency setting unit 26, when the user wants to receive the audio signal transmitted from the FM signal transmission / reception function unit 1, the signal is input from the instruction signal input unit 27 using a one-touch key or the like. The frequency is input and the reception frequency setting unit is instructed by the FM audio reception simple frequency instruction unit 26 in advance, and the reception unit 21 can receive the FM signal of that frequency. Accordingly, various audio signals transmitted from the FM signal transmission / reception function unit 1 are received by the reception unit 21 of the FM radio 2, converted into audio by the audio signal creation unit 22, and predetermined audio signals are output by the audio signal processing / output unit 23. Processing is performed and output from the speaker 24.

  In such an FM radio 2, as described above, the FM signal transmission / reception function unit 1 detects interference, and after that, an appropriate transmission frequency is detected by the operation of each function unit as described above, and a reception frequency setting change guidance output unit. When the reception frequency change guidance is issued from 20, when the user performs confirmation input of the change and the transmission frequency from the FM signal transmission / reception function unit 1 is automatically changed, the user changes the FM from the instruction signal input unit 27 to the FM. The voice reception simple frequency instruction unit 26 is instructed to change to the previously guided frequency, that is, the frequency change adjustment operation instructed by the FM voice reception simple frequency instruction unit 26 of the FM radio 2.

  In the embodiment of the present invention composed of the functional blocks as described above, for example, it can be implemented by sequentially operating according to an operation flow as shown in FIG. In the example shown in FIG. 2, the example in which the FM signal transmission / reception function unit 1 in FIG. 1 is an FM modulator is shown. However, the FM signal transmission / reception function unit 1 can also be used in the same way for an FM transmitter. It doesn't matter if it's external.

  In the transmission frequency adjustment process of the FM modulator shown in FIG. 2, the initial setting of the transmission frequency of the FM modulator is first performed, and similarly, the setting of the simple reception frequency of the FM modulator in the FM radio as the FM signal receiver is The transmission frequency is set to the same frequency as the initial setting value of the transmission frequency performed by the FM modulator. In this state, the audio reproduction signal of the external device using the FM modulator is output as sound from the speaker through the FM radio.

  In such a use state, in the example of the operation flow of FIG. 2, it is determined whether or not there is an interference detection record in the interference detection memory (step S3). Since this process cannot immediately perform the next process when an interference state described later is detected, it is temporarily stored in the interference detector billion unit 10 shown in FIG. 1 for the next process. In this case, it is detected whether or not there is an interference detection record in the interference detection storage unit.

  If it is determined in step S3 that there is no interference detection record in the interference detection memory, it is determined whether or not interference is currently occurring (step S4). In the example of FIG. 1, the signal comparison unit 8 receives the FM signal transmitted from the FM signal transmission / reception function unit 1 to the FM radio 2 and the reception unit 7 as described above. The FM signal is compared, and when both match, it can be determined that there is no interference. Further, when the user thinks that the sound output from the speaker 24 is interfering sound while using the device using the FM modulator, a signal indicating that the interference is caused by manual input or the like. Can be output to the interference detection unit 9.

  When it is determined in step S4 that there is no current interference, the process returns to step S3 and the above operation is repeated. When it is detected in step S4 that interference has occurred as described above, data indicating interference is recorded for subsequent processing (step S5). Thereafter, it is determined whether or not transmission output is being performed from the FM modulator (step S6). This determination is made by detecting the state in which the audio signal transmission detection unit 11 in FIG. 1 outputs the FM audio signal from the FM transmission signal creation unit 4 to the transmission unit 6 in the illustrated embodiment.

  If it is determined in step S6 that an FM audio signal is output from the FM modulator, the process returns to step S3 again and the above operation is repeated. In this case, since it is determined in step S3 that there is an interference detection record in the interference detection memory, the process immediately proceeds to step S6, and this operation is repeated until there is no transmission output from the FM modulator.

  Thereafter, when it is determined in step S6 that the FM audio signal is not output from the FM modulator, the FM radio reception unit built in the FM signal transmission / reception function unit 1 of FIG. 1, that is, the reception unit 7 of FIG. The receivable frequencies are scanned in order (step S7). In that case, the frequency stored in the FM broadcast frequency data storage unit 13 is sequentially scanned in ascending or descending order from the currently used transmission frequency, or the broadcast frequency stored in the FM broadcast frequency data storage unit 13 Alternatively, scanning may be performed in order from the minimum frequency or from the maximum frequency.

  During the scan, a reception intensity level is acquired from the FM radio reception circuit (step S8), and then it is determined whether or not a reception intensity level equal to or higher than a predetermined value is detected (step S9). When the level is detected, it is determined that there is a broadcasting station using that frequency, and the operation is repeated again by returning to step S3.

  At that time, in the same manner as described above, it is determined in step S3 that there is an interference detection record in the interference detection memory, the process proceeds to step S6 to determine whether or not transmission output is being performed from the FM modulator, and then transmission output is performed again. Sometimes, returning to step S3, the previous operation is repeated, and when there is no transmission output, the process proceeds to step S7 and the receivable frequencies are scanned again in order, but at that time, the scans are performed in order from the interrupted frequency in the previous scanning operation. repeat.

  If it is determined in step S9 that a predetermined or higher reception intensity level has not been detected, it is determined that no FM broadcast that interferes with that frequency is received, and it is determined whether or not that frequency is the same as the transmission frequency ( Step S10). Here, the frequency obtained as a result of the current search that is considered not to cause interference is actually the same as the currently transmitted frequency, and the vehicle is temporarily unable to receive it, such as in a place where it cannot receive radio waves. The current transmission frequency is maintained, the process returns to step S3 again, and the above operation is repeated.

  If it is determined in step S10 that it is not the same as the transmission frequency, a reception frequency setting change guide is output (step S11). When the guidance is output, for example, when a monitor or various display screens are present as in a navigation device, the same guidance is displayed and output on that portion, and the user may confirm the frequency change by voice. Next, it is determined whether or not there has been a confirmation input of frequency change from the user (step S12). For example, when there is no confirmation input after waiting for a predetermined time such as 10 seconds, or the frequency is not changed, or the current If the frequency is used for a while and there is a separate input indicating that the frequency change itself is not currently performed, the process returns to step S3 and the above operation is repeated.

  When it is determined in step S12 that the user has received confirmation of frequency change, the frequency of the transmission circuit in the FM modulator is immediately changed to that frequency (step S13). These operations are performed when the appropriate transmission frequency to be changed is detected by the appropriate transmission frequency detection unit 17 in FIG. 1 and when the transmission frequency change instruction unit 18 inputs the confirmation signal from the signal and the confirmation signal input unit 19. The transmission frequency setting unit 5 sets the frequency. Thereby, the output of the FM signal transmitted from the FM modulator is performed at this frequency thereafter.

  Next, the user sets the FM audio reception simple reception frequency in the FM radio 2 to the previously guided frequency. In order to easily adjust the frequency setting by the user, it is preferable to take measures such as displaying the frequency to be changed for a while when guiding the frequency change.

  In the above embodiment, the FM audio output frequency automatic adjusting apparatus according to the present invention can be used as an FM modulator main body, an FM transmitter main body, and further as an FM modulator or FM transmitter incorporated in an audio output device. Although the example which enabled it to utilize in an aspect is shown, when mounting the audio apparatus for vehicles provided with the head unit which has the function of FM radio as an example of this invention, FM modulator is mounted. FIG. 3 shows a functional block diagram of the navigation device when the built-in navigation device is attached externally.

  The example shown in FIG. 3 shows an example in which an FM modulator function unit 47 as the FM transmission / reception function unit shown in FIG. The unit 30 includes a ROM that records software for comprehensively performing various predetermined functions, a CPU and a RAM for processing the software, and controls each functional unit connected thereto. In the illustrated navigation apparatus, a vehicle position detection unit 33 is connected to the system control unit 10 and position data of the GPS receiver 31 is input. Further, if necessary, a travel distance / direction detection unit using a vehicle speed sensor or an angle sensor. By inputting the movement data of the vehicle from 32, the current position of the vehicle is accurately detected.

  In addition, a VICS information input unit 34 including a VICS receiver is provided, and VICS information is captured from a beacon, FM broadcast, or the like. The function of receiving the FM broadcast can also be used as an FM broadcast receiving unit of the FM modulator 47 described later. In the instruction signal input unit 37, an instruction signal for the remote controller 35 or the like by the user in the navigation device is input. Further, a signal of the voice recognition unit 36 that inputs a user instruction signal by processing for recognizing the user's voice as necessary is also input to the instruction signal input unit 37. The instruction signal input unit 37 can input a signal to the interference detection unit 9 of the FM modulator function unit 47, a user's confirmation input to the confirmation signal input unit 19, and the like.

  The data fetching unit 39 fetches necessary map data, facility information, etc. from a map / information data recording medium 38 such as a CD-ROM, DVD-ROM, or hard disk, and the data recording medium is like a hard disk. When data can be easily written, data can be input to the data recording medium so that data imported from outside or data processed by other functional units can be read and used later. I have to.

  In the guidance route guide unit 40, the current location of the vehicle detected by the vehicle position detection unit 33 is fetched, and the phone number is further input by scrolling the map by operating the cursor displayed on the screen or by inputting an address. The destination set by various methods such as the above is taken in, the optimum guide route is calculated under various conditions such as the shortest required time, the shortest distance, and the general road priority, and the image output unit 43 to the display unit 44 on the map screen The left and right turn intersections are displayed in an enlarged manner, and the voice output unit 41 outputs to the speaker 42 to provide voice guidance. From the image output unit 43 and the audio output unit 41, the guide information output by the reception frequency setting change guide output unit 20 of the FM modulator function unit 47 is displayed on the screen, and further output by sound.

  The navigation device shown in FIG. 3 is externally connected to the head unit 46 inside the console through various connection lines as described above. The head unit 46 includes an FM radio, receives FM broadcasts received by an antenna, performs signal processing, and can output from the speaker system 45. The FM audio signal transmitted from the transmitter unit 6 of the FM modulator function unit 47 of the navigation device is connected to the antenna input unit of the FM radio through a signal line and output. After signal processing in the same manner as FM broadcasting, the FM audio signal is mounted on the vehicle. Output from the speaker system 45 in the vehicle.

  The FM modulator function unit 47 has the same functional block configuration as that of the FM signal transmission / reception function unit 1 shown in FIG. 1, and since these have already been described, the redundant description is omitted here. The function unit 47 can perform a desired operation according to the operation flow shown in FIG.

  The FM audio output frequency automatic adjusting method and apparatus according to the present invention can be used as an FM modulator main body, an FM transmitter main body, and further as an FM modulator or FM transmitter incorporated in an audio output device as described above.

It is a functional block diagram in the Example which implements this invention with various aspects. It is an operation | movement flowchart of the Example. It is a functional block diagram in the Example which applied this invention to the navigation apparatus incorporating FM modulator.

Explanation of symbols

1 FM signal transmission / reception function block
2 FM radio 3 Device audio signal input unit 4 FM transmission signal creation unit 5 Transmission frequency setting unit 6 Transmission unit 7 Reception unit 8 Signal comparison unit 9 Interference detection unit 10 Interference detection storage unit 11 Audio signal transmission detection unit 12 Reception frequency change instruction Unit 13 FM broadcast frequency data storage unit 14 reception frequency setting unit 15 reception intensity level detection unit 16 transmission / reception frequency coincidence detection unit 17 proper transmission frequency detection unit 18 transmission frequency change instruction unit 19 confirmation signal input unit 20 reception frequency setting change guidance output unit

Claims (6)

The audio signal of the device is transmitted as an FM audio signal to an external FM radio by a transmission means at a predetermined frequency,
Detecting that the FM audio signal transmitted by the transmission means is interfering with the FM broadcast reception signal received by the FM radio;
Detecting that the FM audio signal is not transmitted from the transmission means;
FM broadcast receiving means receives FM broadcasts in order,
Detecting a proper transmission frequency that is a frequency at which the reception intensity level of the received FM broadcast is a predetermined value or less,
Guide the user to change the transmission frequency to the appropriate transmission frequency,
An FM audio output frequency automatic adjustment method, comprising: changing a transmission frequency of the transmission means when a confirmation signal for changing a reception frequency setting by a user is input. Transmitting means for transmitting the audio signal of the device as an FM audio signal to an external FM radio at a predetermined frequency;
Receiving means for receiving an FM signal;
Interference detection means for detecting that the FM audio signal transmitted by the transmission means interferes with the FM broadcast reception signal received by the FM radio;
An audio signal transmission detecting means for detecting that the FM audio signal is not transmitted by the transmitting means when the interference is detected by the interference detecting means;
A reception intensity level for detecting whether or not the reception intensity level of the FM broadcasts sequentially received by the reception means is equal to or less than a predetermined value when the audio signal transmission detection means detects that no FM audio signal is transmitted. Detection means;
Appropriate transmission frequency detection means for detecting an appropriate transmission frequency whose frequency is equal to or lower than a predetermined value based on the reception intensity level detected by the reception intensity level detection means;
When the appropriate transmission frequency is detected by the appropriate transmission frequency detection means, the reception frequency setting change guidance output means for guiding the user to change and set the reception frequency; and
An FM audio output frequency automatic adjusting device comprising: a transmission frequency changing unit that changes a transmission frequency of the transmission unit when a confirmation signal for changing a reception frequency by a user is input.   3. The FM audio output frequency automatic adjustment device according to claim 2, wherein the interference detection means detects interference when the FM signal transmitted by the transmission means is different from the FM signal received by the reception means. .   3. The FM audio output frequency automatic adjustment device according to claim 2, wherein the interference detection means detects that the user is in an interference state based on an input signal.   3. The FM audio output frequency automatic adjusting apparatus according to claim 2, wherein the transmitting means is connected to the FM radio by wire or wirelessly. 3. The FM sound output frequency automatic adjusting device according to claim 2, wherein the FM sound output frequency automatic adjusting device is built in a sound output device.

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