JPH08265191A - Fm multiplex broadcast receiver - Google Patents

Abstract

PURPOSE: To provide a sense of easiness to the user in the case of being able to receive and to inform a disable-reception-state to the user by informing the end of block processing or frame processing as the reception process. CONSTITUTION: When a control circuit 13 is started, initial data such as menu information, a program number of each program information and a program number of display information are transferred from a ROM 14 to a RAM 15. When synchronization of a first block is taken within a prescribed time, the control circuit 13 displays two asterisks onto a display device 16 in order to inform the reception of an FM multiplex broadcast signal to the user. When the first frame synchronization is taken, a fact of denoting the reception state of the FM multiplex broadcast signal is displayed and when information desired to be displayed is all received, the fact is displayed. In this case, the receiving progress of character information is informed and displayed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an FM multiplex broadcasting receiver.

[0002]

2. Description of the Related Art FM multiplex broadcasting is a broadcasting system for providing a new service by multiplexing characters, graphic information, additional information, etc. in a gap between radio waves of FM audio broadcasting (Japanese Patent Laid-Open No. 3-69).
No. 26). This system has been put to practical use in RDS in Europe and RBDS in the United States. Even in Japan, some broadcasting stations are preparing for the start of services in April 1995. This includes display information such as news, weather forecasts, complementary programs, music programs, traffic information and emergency broadcasts, which are classified according to their contents. This selection is made based on the menu sent from the broadcasting station.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention When an operation for starting reception of FM multiplex broadcasting is performed, even if the user is listening to the FM multiplex broadcasting, the broadcasting station does not send out the FM multiplex signal, or the FM multiplex signal is not transmitted. Of course, the FM multiplex broadcast cannot be received during the time period when no signal is transmitted. Further, when the vehicle is moving by a vehicle or the like and the reception condition is poor and the electric field is weak, the FM multiplex broadcast may not be correctly received and the information may not be displayed. Furthermore, since a plurality of pieces of display information are transmitted, it is impossible to immediately display the information to be displayed. For example, even if the menu information for selecting a program is displayed, the display of the menu may be delayed by receiving another program.

As described above, there are cases where the FM multiplex information is not immediately displayed even if the operation for starting the reception of the FM multiplex broadcast is performed. At this time, when the FM multiplex information is displayed by the operator, However, there is a problem that it is impossible to know whether the FM multiplex information will be displayed if the user waits as it is.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and a first feature thereof is an informing means for performing an informing operation and processing of display information in block units and frame units, and A data demodulation circuit for detecting the end of processing,
The control means is provided to cause the notification means to perform the notification operation based on the detection of the data demodulation circuit.

A second feature is that it is provided with a notifying means for performing a notifying operation, and the control circuit causes the notifying means to perform the notifying operation based on the detection of the end of processing of the data demodulation circuit and the detection of the type number.

[0007]

As the reception progress, the end of the block processing or the frame processing is notified. Further, the end of the block processing or frame processing of the display information to be displayed is notified.

[0008]

Embodiments of the present invention will be described with reference to the drawings. First, the configuration of the FM multiplex broadcast signal received in this embodiment will be described. This FM multiplex broadcast signal complies with Ministry of Posts and Telecommunications Notification No. 461 (August 25, 1994).

The signal of FM multiplex broadcasting is a packet format, and one frame is 288 bits × 272 rows (block).
1 matrix for transmitting data, as shown in FIG.
It is composed of 90 blocks (packets) and 82 parity blocks (parity packets) that transmit the parity in the column direction. The parity packet consists of a block identification code (BIC) and a check code (parity) (FIG. 2).

A program number indicating the type of text information is included in the packet. The position of the program number in the packet will be described with reference to FIG. (A) shows the structure of the packet, and the program number is included in the data packet therein. (B) shows the structure of the data packet, and the program number is included in the data block therein. If the data block is a character / figure 1
It is 44 bits and 160 bits for additional information. (C) shows the structure of a data group for characters / graphics, and is composed of one or a plurality of data blocks. The number of data blocks can be determined by the end code of each data group. The program number is included in the data group data in the data block. The description of the data group of the additional information is omitted. (D) shows the structure of program data, and is composed of one or a plurality of data group data in one data group. The head is program management data, and the following is composed of one or a plurality of page data. The program number is included in both program management data and page data.
(E) shows the structure of the program management data and the page data, and the program number is included in the program data header and the page data header, respectively. (F) shows the beginning of the structure of the program data header and page data header, and the program number is in this. The program number is 8 bits, and the contents of 256 types of character information can be distinguished. The program number 0 indicates the menu information, and the program number 254 indicates the supplement number.

FIG. 4 is a block diagram showing the main part of the embodiment. (1) is an FM receiving circuit, which comprises an FM front end (2), an FM-IF detector (3) and an FM stereo demodulation circuit (4). The FM front end (2) amplifies the signal received from the antenna (5) into a high frequency signal, mixes the high frequency signal and the oscillation signal from the PLL circuit (6) and outputs an intermediate frequency signal. The FM-IF detector (3) performs FM detection on the intermediate frequency signal output from the FM front end (2). The FM stereo demodulation circuit (4) reproduces the L channel and R channel signals using the stereo composite signal input from the FM-IF detector (3), and outputs each channel signal. The signal output from the FM stereo demodulation circuit (4) is amplified by the amplifier circuit (7) and output as voice from the speaker (8).

(9) is a multiplex signal detection circuit, which comprises a multiplex filter (10) and a data demodulation circuit (11). The multiplexing filter (10) removes a voice signal and a noise component from the output signal of the FM front end (2),
LMSK (Level controll) multiplexed at 76 kHz
ed Minimum Shift Keying) signal is extracted. LMSK
Is a modulation method for controlling the size of a multiplexed signal according to the size of a stereo audio signal. The data demodulation circuit (11) demodulates the LMSK signal into a displayable data signal. The signal from the multiplexing filter (10) is subjected to synchronous reproduction and error correction by processing in block units and frame units. When the block-by-block synchronous reproduction process and the error correction process are completed (hereinafter, the block is synchronized), a signal notifying this is sent to the control circuit (13) described later. When the frame-by-frame synchronous reproduction processing and the error correction processing are completed (hereinafter, it is said that the frames are synchronized), a signal notifying this is sent to the control circuit (13) described later. Also, a data demodulation circuit (11)
Detects the program number that distinguishes the contents of the display information, and sends this signal to the control circuit (13).

Reference numeral (12) is an operation section having a plurality of keys as shown in FIG. Among them, FM multiple key (K1)
Is a key for switching operation from another mode to FM multiplex mode, FM multiplex menu key (K2) is a key for performing menu display operation, and selection keys 1 to 6 (K3
..- K8) are keys for operating the program designation of the character information displayed on the menu. Reference numeral (13) is a control circuit, which controls each part based on the operation unit (12) and the multiple signal detection circuit (9). Reference numeral (14) denotes a ROM, which stores programs for operating the control circuit (13), data of initial values, and the like (program information of menu information and program information, program numbers of specific programs, and the like). Reference numeral (15) is a RAM, which stores data necessary for the operation of the control circuit (13). (16)
Is a liquid crystal display device, which displays menu information of FM multiplex broadcasting (display of the display device (16) in FIG. 2), characters of display information, frequency or time of AM / FM broadcasting station, and the like. The number of displayed characters is 15.5 characters x 2 lines or more in accordance with FM multiplex broadcasting.

The operation of the embodiment having the above configuration will be described with reference to the drawings. FIG. 6 is a flow chart showing the main operation of the control circuit (13). When the device is turned on,
Control circuit (13) based on the program of ROM (14)
Will start. At this time, initial value data such as the menu information, the program number of each program information, and the program number of the display information to be displayed is transferred from the ROM (14) to the RAM (15). The program number of the display information to be displayed is, for example, the program number 0 of the menu when the user wants to select a program, and the program number 254 of the complementary program when he or she wants to display a character related to the sound being broadcast. Is.

When the FM multiplex key (K1) is pressed to switch from another mode such as TAPE to the FM multiplex mode (Y in S1), it is visually notified that the FM multiplex broadcast has started to be received. One asterisk "*" is displayed at (S2). When the synchronization of the first one block is achieved within a predetermined time (N in S3 to S5), the control circuit (13) displays two asterisks "**" to notify that the FM multiplex broadcast signal has been caught. Yes (S6). 1
If the blocks are not synchronized within the predetermined time (S
4 N, S5 Y), delete all asterisks,
Display "Not receiving multiplex broadcast" (S7),
Return to step 1. After step S6, when the first one frame is synchronized (S8), three asterisks “**” are sent to notify that FM multiplex broadcasting is being received.
"*" Is displayed (S9). The program number is checked for each received packet, and it is checked whether this program number matches the program number to be displayed stored in the RAM (15) (S9).
10). Receiving continues until they match (N in S10), and when they match (Y in S10), displays four asterisks “*****” to notify that the information you want to display is detected and that information is about to be displayed. Yes (S11). When all the information to be displayed is received (Y in S12), this is displayed (S13). For example, if a complementary program is specified as the program to be displayed, it is possible to notify and display the reception progress of textual information closely related to the voice being broadcast, and if a menu is specified, the user can be notified of the program. It is possible to notify and display the reception progress of the character information that enables selection.

In this way, by the switching operation to the FM multiplex mode, the reception of the FM multiplex broadcast is started, the first signal is confirmed, the signal of the FM multiplex broadcast is caught, and the signal in the middle is confirmed. By confirming that information is being received and information to be displayed while there are a plurality of pieces of display information, the fact that the display is about to be displayed is notified stepwise.

Although the level of the reception status is notified by the number of asterisks "*" displayed in the embodiment, it may be a character representing a word. Further, the notification means is not a liquid crystal display device but a plurality of L
It may be ED. Further, an auditory notifying means such as voice synthesis may be used instead of the visual sense. When the receiver is used as an in-vehicle device, audible notification is preferable for traffic safety.

Further, in the present embodiment, the fact that the data is being received is notified when the first frame is synchronized, but it is also possible to use a counter or a timer together to notify the synchronization after a plurality of frames.

[0019]

Due to the above-mentioned reasons, the FM multiplex information may not be displayed immediately even if the operation of starting the reception of the FM multiplex broadcast is started. At this time, by notifying whether or not the reception is in progress, the user is given a sense of security when the reception is possible, and when the reception is not possible, the user is notified that the reception is not possible even if the user waits as it is.

[Brief description of drawings]

FIG. 1 is a diagram showing the structure of one frame of FM multiplex broadcasting.

FIG. 2 is a diagram showing a structure of a parity packet of FM multiplex broadcasting.

FIG. 3 is a diagram showing a program number in a packet of FM multiplex broadcasting.

FIG. 4 is a block diagram showing an embodiment of the present invention.

FIG. 5 is a diagram illustrating a display device and an operation unit according to an embodiment.

FIG. 6 is a flowchart showing the operation of the embodiment of the present invention.

[Explanation of symbols]

 1 FW reception circuit 8 speaker 9 multiplex signal detection circuit 11 data demodulation circuit 12 operation unit 13 control circuit 15 RAM 16 display device K2 menu key

Claims (2)

[Claims] 1. A data demodulation circuit for performing synchronous reproduction processing and error correction processing by packet-based display information in a packet format, which is included in an FM demodulated signal and in which one frame is composed of a plurality of blocks, by processing in block units and frame units. F with
In the M-multiplex broadcast receiving device, an informing means for performing an informing operation and the data demodulation circuit detect the end of the processing in the block unit or the processing in the frame unit and cause the informing means to perform the informing operation based on the detection signal. An FM multiplex broadcast receiving apparatus comprising a control circuit. 2. A plurality of types of display information, each of which is a packet type information signal included in an FM demodulated signal and in which one frame is composed of a plurality of blocks, each having a type number, in block units and frames. A data demodulation circuit for performing synchronous reproduction processing and error correction processing by unit processing and detecting the type number; and a display means for displaying display information,
Storage means for storing the type number of the display information to be displayed,
An FM multiplex broadcast receiving apparatus including a control circuit for displaying the display information having the type number stored in the storage means when the display information is completely received, the notification means performing the notification operation is provided, and the data demodulation circuit includes the block unit. Is detected or the end of the processing in units of frames is detected, and the control circuit causes the notification means to perform a notification operation based on the detection of the processing end of the data demodulation circuit and the detection of the type number. Receiver.