JP3164462B2 - FM multiplex broadcast receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an FM multiplex broadcast receiver, and more particularly to a technique for demodulating traffic information by synchronizing a receiver with a traffic information station transmitting traffic information superimposed on an FM multiplex broadcast signal. About.

[0002]

2. Description of the Related Art Conventionally, a car radio as a mobile receiver has been required to provide not only data information such as traffic information but also other useful data information. At present, RDS (Radio Data System) is put to practical use in Europe by EBU (European Broadcasting Union). On the other hand, in Japan, the Telecommunications Technology Council has been working to provide FM as much as possible to provide additional information to the extent possible by effectively utilizing existing FM broadcast waves and equipment.
Multiplex broadcasting has been proposed and is being put to practical use.

[0003] This FM multiplex broadcasting is a system in which various digital data information is superimposed on an FM broadcasting signal and transmitted.
The transmission contents include (1) characters and graphics and (2) receiver control signals (additional information).

[0004] The encoding system is shared with TV multiplex teletext broadcasting which has already been put to practical use, and is also simplified. That is, it is for facilitating the exchange of programs in the production of TV multiplex text broadcasting and FM multiplex text / graphic broadcasting. The outline of the coded and transmitted character or graphic set, the contents of its control, and the contents of the additional information currently considered are shown below. (1) Character set Kanji, hiragana, katakana, alphanumeric characters, dynamically redefined character set, mosaic, geometric, etc. (2) Graphic Photographic graphic transmitted by pixel, mosaic graphic / dynamic redefined character set graphic transmitted by character code, geometric graphic transmitted by graphic description instruction. (3) Character control Character size control, color control, flushing, concealment, etc. (4) Additional information Broadcast station name, program category, time, program identification, traffic information flag, broadcast station identification, alternative frequency list, etc. As described above, in the FM multiplex broadcast, various messages are multiplexed and transmitted to the FM broadcast being received, so that it is possible to obtain information that has never been seen before.

[0005] On the other hand, regarding the AM band traffic information, the tuning has been conventionally performed by a simple operation at the time of reception.
T. INFO (Traffic information)
n) is provided with a dedicated key. A plurality of modes including an external input provided in the receiver, such as a radio, a tape, and a CD, can be operated by a single key operation from any mode.
It could tune to a traffic information station of 1620 kHz or AM1629 kHz and output voice.

[0006]

SUMMARY OF THE INVENTION The present invention relates to the above AM
The conventional system, which can only receive traffic information, can be tuned to the traffic information station in the FM multiplex broadcasting in the FM band by a simple operation so that the traffic information can be demodulated. Effective data information.

[0007]

The object, according to an aspect of the according to the present invention, an FM multiplex broadcast receiver which demodulates the multiplexed data reproducing including the identification code or the like which is sent superimposed on the FM multiplex broadcast signals, a plurality Voice selecting means for selecting and outputting one of the music sources, a display unit for displaying characters / graphics based on the multiplexed data, and receiving traffic information
Operating means, and the sound selecting means is for other than FM multiplex broadcasting.
While the music source is selected and output, the operation means is operated.
, The FM multiplex broadcasting station is selected and character / graphic information is
And display the traffic information on the display unit,
A system that keeps the source selection state of the audio selection means as it is
It is solved by means .

[0008]

In the FM multiplex receiver having the above configuration, the operating means for receiving the traffic information can be operated.
And FM multiplex broadcasting in whatever mode the receiver is currently in
The traffic information transmission station is selected from the transmission stations, and the traffic information transmission station is selected.
Traffic information consisting of text / graphic information
And the source selection status of the voice selection means.
State is maintained as it is. Easy access to traffic information
Thus, the display unit and the audio output are effectively used.

[0009]

FIG. 1 is a block diagram of a main part of an FM multiplex broadcast receiver for realizing traffic information reception according to the present invention. 1
Is a PLL circuit, which outputs a predetermined voltage signal corresponding to a station to be received to the FM front end 2. The FM front end 2 receives a broadcast input from the antenna ANT based on the voltage signal, and receives a predetermined intermediate frequency signal (I
F). 3 is an intermediate frequency amplification detection circuit,
The intermediate frequency signal converted by the M front end 2 is amplified to a predetermined level and detected.

Reference numeral 7 denotes an FM multiplex decoder circuit which demodulates a multiplex program composed of FM multiplex data transmitted at a predetermined transmission timing. Reference numeral 8 denotes an error correction circuit which detects an error of the multiplexed data demodulated by the FM multiplex decoder circuit 7 while synchronizing each group and corrects the error.

Reference numeral 9 denotes a signal meter circuit which detects the level of the reception state of the receiving station by monitoring the signal strength (for example, electric field strength) of the intermediate frequency signal output from the intermediate frequency amplification detection circuit 3.

Reference numeral 10 denotes a display unit for displaying characters, figures, and the like from the multiplexed data. Reference numeral 11 denotes a control unit for controlling the entire operation of the FM multiplex broadcasting receiver, a display control unit 11a for displaying characters, graphics, and the like on the display unit 10 based on the multiplexed data, and an error rate for detecting an error rate of the multiplexed data. A detecting unit 11b, a checking unit 11c for checking whether the error rate is within an allowable range, an identification code detecting unit 11d for detecting an identification code in the multiplexed data, an error rate allowable range, and storing for each identification code. And a storage unit 11e having a plurality of storage areas divided into a plurality of storage areas.

Reference numeral 12 denotes an operation unit having operation keys for operating the FM multiplex broadcast receiver and displaying the multiplex data stored in the storage unit 11e on the display unit 10.
In this embodiment, T.C. INF
O key 12a, up / down key 12b for up / down tuning frequency, seek key 12c for automatic tuning, and memory key 1 for storing the selected station
2d.

[0014] 13 is a PLL circuit of the AM band, and outputs the predetermined voltage signals corresponding to be the receiving station to the AM front-end 14. The AM front end 14 receives a broadcast input from the antenna ANT based on the voltage signal, and converts the broadcast into a predetermined intermediate frequency signal (IF). Reference numeral 15 denotes an intermediate frequency amplification detection circuit, which is an AM front end 14.
Is amplified to a predetermined level and detected. A signal meter circuit 16 detects the level of the reception state of the receiving station by monitoring the signal strength (for example, electric field strength) of the intermediate frequency signal output from the intermediate frequency amplification detection circuit 15.

Reference numeral 17 denotes a voice selecting means, which is controlled by the control unit 11 to switch, and is connected to a CD connected to the receiver,
The audio output of a tape or the like, the audio output of the FM intermediate frequency amplification detection circuit 3 and the audio output of the AM intermediate frequency amplification detection circuit 15 are selected and switched, and output as an audio output to an amplifier and a speaker (not shown). . For the sake of simplicity, the MPX circuit and the operation unit 1 for FM stereo signal demodulation not directly related to the present invention.
Some of the operation keys provided in 2 are omitted.

The operation of the FM multiplex broadcasting receiver shown in FIG. 1 will be described below. A broadcast in which multiplexed data is superimposed on the basis of a voltage signal corresponding to a transmission frequency of a predetermined broadcast station output from the FM or AM band PLL circuit 1 or 13 in accordance with an operation selection of the operation unit 12 of the FM multiplex broadcast receiver. The radio wave is received by the FM or AM front end 2 or 14 via the antenna ANT, amplified and detected by the intermediate frequency amplification detection circuit 3 or 15 and output as an audio signal, and either FM or AM is output by the audio selection means 17. Selected and output.

In the general reception state as described above, in order to obtain traffic information, the T.P. INFO key 1
When the user operates 2a, the control unit 11 activates the PLL circuit 1 or 13 to start an auto seek to select a station transmitting traffic information, regardless of the mode of operation of the receiver. . That is, the operation mode until then is C
In the case of D or tape, the sound selecting means 17 is switched to AM or FM radio output, and if the operation mode is radio reception, seek starts from the frequency band that has been received, and If there is no traffic information transmitting station, the mobile station moves to another frequency band and performs a seek operation. INFO
Release the mode instructed by the operation of the key 12a,
Returns to the mode before the key operation.

In the above-described seek operation, the AM band is 1
For the 620 and 1629 kHz and FM bands, all channel steps are checked, and if the received field strength of a station is equal to or greater than a predetermined value, tuning is temporarily fixed to the station.
If the station is in the AM band, the voice selecting means 1
7 is switched to AM to output audio. If the station is in the FM band, the multiplexed data is demodulated by the FM multiplex decoder circuit 7, and the service identification code and the program number are checked by the identification code detection circuit 11d.

If the checked service identification code and program number belong to the traffic information station, the display control section 11a switches the display on the display section 10 to that for traffic information.

If the demodulated traffic information is character or graphic information, the voice selecting means 17 outputs The sound before the INFO key 12a is operated is selected and output, and only the display output to the display unit 10 is switched.

If the demodulated traffic information is voice information,
The voice selecting means 17 outputs the T. The voice before the INFO key 12a is operated is switched to the multiplex voice of the traffic information. In this case, when the announcement of the multiplexed voice of the traffic information is completed, the voice is returned to the original source voice, and the multiplexed voice is switched every time the information is updated.

The display control section 11a shares the page of the display screen with the display section 10 with the up / down key 12b for tuning, so that the page number is up / down. Also, T.I. The operation mode of the INFO key 12a is configured so that the key can be operated again or released by another source, for example, a play key of a CD.

If the above-mentioned station whose channel has been tuned by the seek operation and whose tuning has been temporarily fixed is not the desired one, T.D. INF
By operating the seek key 12c in the O key 12a operation mode, another station can be selected.

Although the traffic information station selection according to the above configuration is centered on the seek operation, the next channel selection can be made easier by writing the selected traffic information station to the frequency memory area. That is, the multiplexed data of the FM station being received is demodulated by the FM multiplex decoder circuit 7, and it is determined whether or not the station is a traffic information station based on the service identification code and the program number. A memory area (not shown) connected to the memory key 12d is set in a writable state and automatically or
By manipulating d, the frequency is written into the memory.

The memory has an AM band of 1620 kHz and 16 MHz.
It has a memory area of about 29 kHz and about 6 stations in the FM band. Each time the INFO key 12a is operated, the AM16
20kHz → AM1629kHz → FM 1 → FM 2
It is possible to tune only to the traffic information office in a toggle manner, such as: FM6 → AM1620kHz.
Further, audio switching is performed in AM, and display switching /
Voice switching can also be performed.

[0026] In the FM multiplex broadcast receiver configured as described above, the listener listens to the main audio broadcast program.
In some cases, they miss a traffic information broadcast, which is a counter program. For this purpose, the present embodiment is configured so that multiplexed data is sequentially taken in and stored, and can be reproduced as information in a timely manner. The explanation is described below.

The data demodulated by the FM multiplex decoder circuit 7 is input to the control unit 11 after the data error is corrected by the error correction circuit 8, and the error rate detection unit 11b of the control unit 11 detects the error rate. . Note that the multiplexed data output from the error correction circuit 8 is provided with a flag such as no error, corrected, or uncorrectable, and the error rate of the data can be detected by counting the flag.

The error rate detected by the error rate detection unit 11b is checked by a check unit 11c to determine whether the error rate is within the range of the error rate stored in the storage unit 11e. If it is, it is directly input to the identification code detection unit 11d in the multiplexed data, and the identification code is sequentially stored in the storage area of the corresponding storage unit 11e,
When the storage capacity is full, the oldest data is discarded in the order of the oldest, and new data is always written. In order to obtain traffic information from the multiplexed data stored in the storage unit 11e by the user, an operation key (not shown) is used. When operated, the operation command is input, and the display control unit 11a calls the traffic information data from the storage area corresponding to the traffic information identification code stored in the storage unit 11e, and displays the traffic information on the display unit 10 in chronological order. It can be displayed and used.

In the above embodiment, the display data is stored and displayed. However, in addition to the display data, audio data and the like may be stored and reproduced.

[0030]

As described above, according to the present invention, traffic information
By operating the operating means for receiving
FM multiplex broadcasting station is selected even if a music source is selected
Traffic information consisting of text and graphic information is displayed on the display
And the source selection status of the audio selection means remains unchanged.
The traffic information is easily maintained and displayed.
And the audio output are effectively used.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

[Explanation of symbols]

1 FM band PLL circuit 2 FM front end 7 FM multiplex decoder circuit 10 Display unit 11 Control unit 12 Operation unit 12a INFO (Traffic Information)
) key (traffic information reception operation means) 12c seek key 13 AM band PLL circuit 14 AM front end 17 voice selection means

Claims (1)

(57) [Claims] 1. An FDM for demodulating and reproducing multiplexed data including an identification code and the like which is transmitted by being superimposed on an FM multiplex broadcast signal.
In the M multiplex broadcasting receiver, a sound selecting means for selecting and outputting one from a plurality of music sources, a display unit for displaying characters and graphics based on the multiplex data, and receiving traffic information
Operating means for causing the voice selection means to perform FM multiplexing
Operating means during selection and output of a music source other than broadcast
Is operated, the FM multiplex broadcasting station is selected and the character and
When traffic information composed of graphic information is displayed on the display unit,
In both cases, the source selection state of the audio selection means is maintained as it is.
FM multiplex broadcast receiver characterized by comprising a control means for lifting.