JPH11243347A - Fm multiplexed broadcasting receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an FM multiplexed broadcasting receiver that reduces time until useful information is shown. SOLUTION: This receiver 1 is provided with a front end processor 12, an intermediate amplification/FM detection circuit 14, a filter circuit 18, a level controlled minimum shift keying demodulating circuit 20, an error detection/ correction circuit 24 and a CPU 30 in order to receive program data multiplexed in FM multiplexed broadcasting. The CPU 30 successively stores the program data included in the an FM multiplexed broadcasting in a RAM 32 for data storage, and when a receiving frequency is changed, eliminates program data other than what corresponds to preliminarily designated program classes among the stored program data. The contents of the program data that are not eliminated but stored are shown even immediately after the frequency is changed.

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 for receiving FM multiplex broadcasts and displaying various programs multiplexed on the FM multiplex broadcasts.

[0002]

2. Description of the Related Art Data radio channels DARC (Da
In FM multiplex broadcasting using the “ta Radio Channel” system, characters and graphics are converted into digital data and encoded, and a multiplexed signal having a subcarrier frequency of 76 kHz is frequency-multiplexed into a stereo baseband signal and FM-modulated. Currently, three types of service levels from level 1 to level 3 are assumed for characters and graphics to be broadcast. Level 1 is a service for a receiver capable of displaying a text (15 characters × 2 lines) and a header line, and mainly includes information in characters. Level 2 is a service for receivers capable of displaying a text (15.5 characters × 8 lines) and a header line, and is suitable for sending figures and maps. Level 3 is
The service provides traffic information data for a car navigation system having a map display function using a CD-ROM or the like.

When an FM multiplex broadcast is received by an FM multiplex broadcast receiver, the received program data is stored in a memory. And, for example, remote control (remote control)
When display of a program is instructed by a key operation of the unit, the corresponding program data is read from the memory and displayed on a display device or the like. Also, when a change in the reception frequency is instructed by key operation of the remote control unit,
The receiving frequency is changed according to this instruction, and the program data which has been received and stored in the memory is deleted,
New program data received after the change of the reception frequency is stored in the memory. Note that each program included in one reception frequency is repeatedly distributed in a period of several minutes to several tens of minutes, and all programs can be received after a certain period of time has elapsed regardless of the start timing. ing.

[0004]

By the way, the conventional FM
The multiplex broadcast receiver receives program data included in the FM multiplex broadcast of the new reception frequency every time the reception frequency is switched and performs an operation of storing the program data in the memory, so that useful information such as program contents is displayed. There was a problem that it takes time until.

[0005] As described above, it takes several minutes to several tens of minutes to complete the reception of each program included in the FM multiplex broadcast of a certain frequency, but the menu required for selecting each program whose response is in progress is required. The screen is distributed at intervals of a few minutes shorter than this cycle. Therefore, it takes about two to three minutes to display the menu screen in a long case, and then it takes about ten minutes to display all selectable programs according to the menu screen. .

[0006] Therefore, until the menu screen is received, for example, a message such as "Character information is being received. Please wait for a while." Is displayed, and no program content is displayed. Had to wait for nothing to be displayed. Immediately after the menu screen is displayed, the reception-completed program (or the reception-completed page if the program is composed of a plurality of pages)
Therefore, in many cases, only a specific screen is displayed, and it has been necessary to wait at least a few more minutes before many screens can be selected.

[0007] The present invention has been made in view of the above points, and an object of the present invention is to provide an FM multiplex broadcast receiver in which the time required for displaying useful information is shortened.

[0008]

In order to solve the above-mentioned problems, an FM multiplex broadcast receiver according to the present invention does not delete multiplexed data of an FM multiplex broadcast before a change when changing a reception frequency. And the content of the multiplexed data that has been left after the change is displayed.

[0009] Specifically, the data receiving means
The multiplex broadcast is received, and the multiplexed data contained therein is extracted and stored in the data storage means. When the receiving state of the data receiving means is changed, for example, switching to FM multiplex broadcasting of another receiving frequency, other types of receiving modes such as AM broadcasting, and other types of receiving such as CD (compact disk) players In the case where the operation mode is switched to the above operation mode and the reception operation of the FM multiplex broadcast is stopped, the storage control unit does not delete at least a part of the multiplexed data stored in the data storage unit before the reception state is changed. If there is other multiplexed data, it is deleted, and the contents of the multiplexed data that has not been deleted can be displayed by the content display means. Therefore, even if the reception frequency is changed or the operation mode is switched to an operation mode other than the FM multiplex broadcast reception mode, the storage state is maintained without being deleted even if preparation for displaying new contents is not completed. The content of the multiplexed data being displayed can be displayed, and the time during which no useful information is displayed at all, that is, the time until the useful information is displayed, can be shortened.

[0010] In addition, multiplexed data that is not required by the user is specified by specifying multiplexed data that maintains the stored state without being deleted by the data specifying means and leaves only the specified multiplexed data. Is deleted from the data storage means, so that the data storage means can be used efficiently. In particular, when the FM multiplex broadcasting corresponds to the data radio channel system, it is determined whether or not the multiplexed data stored in the data storage means is the multiplexed data specified by the data specifying means. Is preferably performed based on the data identification of the multiplexed data and the program number. The type (category) of the multiplexed data can be specified by the data identification and the program number, and the storage control means determines the multiplexed data to maintain the storage state on the basis of the data identification and the program number. Multiplexed data to be extracted can be efficiently extracted.

Preferably, the multiplexed data is stored by the data storage means for each FM multiplex broadcast, and the content display means displays contents corresponding to each FM multiplex broadcast. By storing the multiplexed data corresponding to each of the received FM multiplex broadcasts, the multiplexed data that has been left without being deleted and the multiplexed data of the newly received FM multiplex broadcast can be managed so that they can be distinguished from each other. can do. In particular, when FM multiplex broadcasting corresponds to the data radio channel system, it is preferable to use the broadcast station identification information included in the multiplexed data. By using the broadcast station identification information, each FM multiplex broadcast can be associated with the multiplexed data contained therein, and each FM multiplex broadcast can be associated with each FM multiplex broadcast.
The content of the multiplexed data can be displayed for each M multiplex broadcast.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention is shown in FIG.
When switching the receiving frequency, the M multiplex broadcasting receiver can store the stored program data corresponding to the receiving frequency before the switching without deleting it and display the program data immediately after the switching of the receiving frequency. There is a feature in doing.
Hereinafter, an FM multiplex broadcast receiver according to an embodiment will be described with reference to the drawings.

FIG. 1 shows an embodiment of the present invention.
It is a figure showing the composition of M multiplex broadcast receiver. F shown in FIG.
The M multiplex broadcast receiver 1 includes a front end (F / E) 12, an intermediate frequency amplification / FM detection circuit (IF) for extracting stereo sound from an FM broadcast signal received by an antenna 10.
/ DET) 14, a noise canceller / stereo demodulation circuit (NC / MPX) 16, and a filter circuit 18 for separating and demodulating the FM multiplex broadcast data contained in the received FM broadcast signal, a LMSK (Level controlled Minimizer)
um Shift Keying) A demodulation circuit 20, a synchronization circuit 22, and an error detection / correction circuit 24 are provided. By performing various processes on the separated FM multiplex broadcast data, various information such as characters and graphics is displayed on the display unit 36. CPU3 to display
0, a data storage RAM 32, and a display RAM 34, and a tuning circuit 38 for detecting receivable FM broadcasts and switching the reception frequency. Also, this FM
The multiplex broadcast receiver 1 includes an operation unit 40 having various operation keys for a user to operate.

The front end 12 includes an antenna tuning circuit, a high-frequency amplifier circuit, a local oscillator circuit, a mixing circuit, and the like. The front end 12 performs high-frequency amplification on an FM broadcast signal input from the antenna 10 and performs predetermined frequency conversion. I do. For example, when an FM broadcast signal of a desired frequency to be received is input to the front end 12, 10.7 MH
z is converted to an intermediate frequency signal. Intermediate frequency amplification / FM
The detection circuit 14 amplifies the intermediate frequency signal output from the front end 12, performs a tuning operation, and performs FM detection on the tuning result. Further, the noise canceller / stereo demodulation circuit 16 performs intermediate frequency amplification /
After removing a noise component included in the FM stereo composite signal after the FM detection output from the FM detection circuit 14, the L component and the R component of the stereo sound are separated.

The filter circuit 18 separates a multiplex signal contained in the signal after the FM detection.
As shown in FIG. 2, the signal after FM detection has a frequency of 76 kHz.
The preceding and following FM multiplex broadcast signals are included, and only this FM multiplex broadcast signal is extracted by the filter circuit 18.
The LMSK demodulation circuit 20 performs delay detection on the LMSK modulated signal, which is a multiplex signal output from the filter circuit 18, to reproduce a bit clock and demodulate a bit data string. The synchronization circuit 22 detects the block synchronization and the frame synchronization with respect to the bit data string output from the LMSK demodulation circuit 20.
Is a CRC for this synchronized bit data sequence.
(Cyclic Redundancy Check) to detect errors and correct any errors. For example,
Error correction is performed by a product code using the (272, 190) shortened difference set cyclic code in both vertical and horizontal directions, and error correction is performed with high probability.

The CPU 30 extracts group data and program data based on data (data packets) output from the error detection and correction circuit 24. The extracted program data is stored in a data storage RAM 3 together with various data such as service identification SI and broadcast station identification (details will be described later).
2 is stored. The display RAM 34 stores bit data corresponding to a display image, and the stored contents are displayed on the display unit 36.

The CPU 30 allows the user to operate the operation unit 40.
Is operated to specify a program type such as news or traffic information, program data corresponding to the specified program type among the program data stored in the data storage RAM 32 is continued even after the reception frequency is switched. The data storage RAM 32 is controlled to store the data.

The tuning circuit 38 is for setting the receiving frequency of the FM multiplex broadcasting receiver 1, and forms a PLL (phase locked loop) together with a local oscillation circuit in the front end 12. For example, it has a frequency dividing circuit composed of a programmable counter, and by changing the frequency dividing ratio according to an instruction from the CPU 30, the front end 1
The reception frequency is switched by changing the oscillation frequency of the local oscillation circuit in 2.

The operation unit 40 has a "program display" key for instructing the start of program display, a "broadcast station switching" key for switching the program to be displayed for each FM multiplex broadcast (for each broadcast station), and a menu program. Numeric keys for indicating which program is to be displayed on the display unit 36 when displayed, a "reception frequency switch" key for changing the reception frequency, and continuing to the data storage RAM 32 when the reception frequency is switched A "program type designation" key for designating the program type of the program data to be stored, and a "menu program display" key for designating the display of a menu program. It is provided with a “page forward” key, a “page backward” key, and the like for performing a return.

The above-described front end 12, intermediate frequency amplification / FM detection circuit 14, filter circuit 18, LMSK demodulation circuit 20, synchronization circuit 22, error detection and correction circuit 24, C
The PU 30 is used as a data receiving means by the data storage RAM 32.
Are the data storage means, the CPU 30, the display RAM 34,
The display unit 36 corresponds to the content display unit, the CPU 30 corresponds to the storage control unit, and the operation unit 40 corresponds to the data designation unit.

Next, the hierarchical structure of FM multiplex broadcasting using the DARC system will be described. The hierarchical structure of the DARC to be processed by the FM multiplex broadcast receiver 1 includes a layer 1 for a transmission path, a layer 2 for error correction, a layer 3 for a data packet, a layer 4 for a data group, a program 4 Is included in the hierarchy 5.

The layer 1 of the transmission line corresponds to the signal after FM detection (baseband signal) output from the above-described intermediate frequency amplification / FM detection circuit 14. As shown in FIG. 2, the signal after FM detection has an FM of about 76 kHz.
A multiplex broadcast signal is included. Only the FM multiplex broadcast signal is separated by the filter circuit 18 and passed through the LMSK demodulation circuit 20 to obtain FM multiplex broadcast data corresponding to the FM multiplex broadcast signal.

The layer 2 for error correction shows a frame structure for performing error detection and error correction. FIG.
3 is a diagram showing a frame structure corresponding to layer 2. FIG. As shown in the figure, the FM multiplex broadcast data output from the LMSK demodulation circuit 20 is composed of a total of 272 blocks per frame, of which 190 blocks are blocks containing data packets, and the remaining 82 blocks are parity packets. It is a block containing. These 82 blocks are distributed among blocks including data packets.

Each block including a data packet is a 16-bit block identification code BIC (Block Iden).
tify Code), a data packet consisting of 176 bits of data, a 14-bit CRC code, and an 82-bit parity (horizontal code) for error detection and correction. Further, the block including the parity packet includes a 16-bit block identification code BIC, a 190-bit parity (vertical code) packet, and an 82-bit error correction parity (horizontal code).

The identification code of the first 13 blocks including the data packet is BIC1, and the identification code of the next 123 blocks including the data packet is BIIC.
C3, the identification code of the next 13 blocks including the data block is BIC2, and the identification code of the last 123 blocks including the data block is BIIC.
C3. The identification code of each block including the parity packet is BIC4.

The synchronization circuit 22 has a block identification code BIC.
Is detected for each block to achieve block synchronization, and BIC1 is placed next to the block identification code BIC4.
Is detected, frame synchronization is obtained every 272 blocks. Therefore, when the number of times the block identification code cannot be detected in such an order occurs at a predetermined rate, block synchronization is lost, and when frame synchronization is not achieved at a predetermined rate, frame synchronization is lost.

Also, since a block containing a data packet contains a CRC code and each block contained in one frame contains a parity (horizontal code) for error detection and correction. By using the parity, it is possible to perform a correction process after the error detection and correction circuit 24 detects an error. Error detection and correction circuit 2
4 outputs only data packets included in each block after error correction is performed in this manner.

Layer 3 shows the structure of a data packet, the details of which are shown in FIG. As shown in the figure, each data packet is configured to include a 32-bit prefix and a 144-bit data block or a 16-bit prefix and a 160-bit data block. The prefix at the beginning is added to identify a data block as information content, and includes a service identification SI, a decoding identification flag, an information end flag, an update flag, a data group number, and a data packet number. Service identification SI of first 4 bits
Is used to identify a program. For example, it is "0010" in the case of a general information program such as news, traffic information, weather information, and the like. In the case of additional information such as broadcast station identification and time information, "0010" is used. 0000 ".

Layer 4 shows the structure of a data group formed by collecting a plurality of data blocks included in the above-described data packet. This data group is
In the data packet of layer 3, data blocks having the same service identification SI, the same data group number, and the same update flag are arranged in order from the data packet number "0" to the data block in which the information end flag is set. is there. This data group has a different configuration for sending character / graphic information and sending additional information. As shown in FIG. 5, the data group for transmitting character / graphic information includes a start code SOH, a data group link code DGL, a data group size, data group data, a length adjustment NULL, an end code, and a CRC. One data group corresponds to one page of data displayed on the display unit 36. On the other hand, as shown in FIG. 6, a data group for transmitting additional information includes a segment, a length adjustment N, which is an information unit for transmitting additional information.
It consists of ULL and CRC.

Layer 5 shows the structure of program data in which a plurality of data group data included in the above-mentioned data group are formed in the case of transmitting character / graphic information. As shown in FIG. 7, the program data is composed of a plurality of data groups. The first data group is used as program management data, and the subsequent data group is used as page data. The program management data includes information related to the entire program such as a program number and the total number of program pages, and each page data includes information of each page displayed on the display unit 36. Each of the program management data and the page data has a common structure, and has a data header including an information separation code RS, a data header parameter, and data header data, and a data unit group following the data header.

FIG. 8 is a diagram showing an example of data header data (program data header data) included in the data header of the program management data. As shown in the figure, the program data header data includes various information such as a program number assigned to each program in the range of 0 to 255 and the total number of program pages excluding the program management data. The program number assigned to each program is predetermined according to the program content. For example, a program number “0” is assigned to a menu program, and news, traffic information, and weather information, which are general information programs, are respectively assigned. Program number "1"-"19", "40"-
“79”, “100” to “149” are assigned.

FIG. 9 is a diagram showing an example of data header data (page data header data) included in the data header of page data. As shown in the figure, the page data header data includes the above-mentioned program number and various information such as a page number in each program.

As shown in FIG. 10, each data unit constituting the data unit group has an information separating code U
S, a data unit parameter, a data unit link flag code DUL, a data unit size, and data unit data. The data unit parameter therein indicates the content of the data unit data.

On the other hand, in the case of transmitting additional information, layer 5
Indicates a segment which is an information unit for transmitting additional information. Each segment is composed of a segment header and segment data as shown in FIG. The first segment header includes a segment identification and a segment length. The segment identification of the first four bits is for identifying the information content of the segment data. FIG. 12 is a diagram illustrating a specific example of segment identification. For example, when the segment identification is “0001”, the subsequent segment data includes “broadcasting station identification”.

Next, the F of the present embodiment whose configuration is shown in FIG.
The operation of the M multiplex broadcast receiver 1 will be described. For example, a description will be given by taking a program corresponding to level 1 as an example.
FIG. 13 is a diagram showing an operation procedure of receiving program data in the FM multiplex broadcast receiver 1 of the present embodiment. It is assumed that any FM multiplex broadcast is currently being received, and the received program data is stored in the data storage RAM 32 as needed.

In parallel with the operation of storing the program data being received in the data storage RAM 32, the CPU 30 presses the "reception frequency switching" key on the operation unit 40 to instruct the reception frequency to be changed. If a change of the reception frequency is instructed, the program data corresponding to the program type specified in advance by the user is selected from the program data stored in the data storage RAM 32 (step 100). Delete program data other than (step 10)
1).

For example, the program type can be specified by pressing the "program type specification" key on the operation unit 40 when the power of the FM multiplex broadcast receiver 1 is turned on or the like. This is performed by selecting one or more program types (categories). Further, which program data corresponds to which program type is determined based on the service identification SI and the program number described above. For example, when news is specified as the program type, the CPU 30 determines that the service identification SI is “0010” and the program number is “1” to “1” in the received program data.
Only the program data included in “19” is stored without being deleted, and a process of deleting other program data is performed.
Since the menu program is required for a program display operation described later, when program data (program number “0”) corresponding to the menu program is received, this program data is also stored without being deleted. You.

Next, the CPU 30 issues an instruction to the tuning circuit 38 to change the receiving frequency (step 102).
The program data included in the FM multiplex broadcast of the new reception frequency is received (step 103), and the received program data is sequentially stored in the data storage RAM 32 (step 1).
04). Specifically, when the data of each block shown in FIG. 3 is output from the LMSK demodulation circuit 20 after the reception frequency is changed, the synchronization is performed by the synchronization circuit 22 based on the block identification code BIC of the first 16 bits of each block. Block synchronization is achieved. The error detection and correction circuit 24 performs error detection based on the CRC added to the data packet, and when an error is detected, performs error correction based on the parity. Thus, the error-corrected data packet corresponding to the layer 3 is output from the error detection and correction circuit 24 and input to the CPU 30. CP
When a data packet is input from the error detection and correction circuit 24, the U30 collects data blocks having the same data group number based on the service identification SI, the update flag, and the like included in the prefix of the sequentially input data packet. A data group (program management data or page data) corresponding to layer 4 is created, and those having the same program number included in the data header of each data group are collected to create program data corresponding to layer 5, Data storage RAM 3 together with the service identification SI to be transmitted and the broadcast station identification included in the additional information received at the same time.
2 is stored. By storing not only the program data but also the corresponding service identification SI and broadcast station identification, it is possible to recognize which program type of which broadcast station each stored program data belongs to.

Thus, every time the reception frequency is changed,
An operation of sequentially storing newly received program data after frequency change while leaving program data corresponding to the specified program type without deleting it is repeated, so that a plurality of broadcast stations (reception frequencies) Of the program data included in the FM multiplex broadcast, data corresponding to the program type designated by the user is stored.

FIG. 14 is a diagram showing an example of data stored in the data storage RAM 32. For example, the broadcasting station identification (broadcasting company number) has been "1" and "2"
FM multiplex broadcast was received, and now the broadcaster identification is "3"
It is assumed that the FM multiplex broadcast is received. It is also assumed that “news” is specified as a program type by the user.

As shown in FIG. 14, the program data included in the FM multiplex broadcasts with the broadcast station identifications “1” and “2” received so far is included in the program type “news” in the received program data. Corresponding program data (service identification SI is "0010" and program number is "1" to "19")
And only the program data of the menu program (the service identification SI is “0010” and the program number is “0”) are stored in the data storage RAM 32 without being deleted. As for the program data included in the currently multiplexed FM multiplex broadcast with the broadcast station identification “3”, all the received program data are stored in the data storage RAM 32.

In parallel with the above-described program data storing operation, the CPU 30 performs a display operation corresponding to the received program data. Next, the display operation will be described. FIG.
FIG. 5 is a diagram showing an operation procedure for displaying program data in the FM multiplex broadcast receiver 1 of the present embodiment.

The CPU 30 determines whether or not the user has pressed the "program display" key of the operation unit 40 to instruct program display (step 200). It is determined whether or not the program data of the menu program has already been received in the currently received FM multiplex broadcast (step 201). Specifically, the CPU 30 analyzes the program number (“0” in the case of a menu program) of the program data stored in the data storage RAM 32 and the broadcast station identification and the service identification SI corresponding to the program number. It is determined whether or not the program data of the currently multiplexed FM multiplex broadcast menu program is already stored in the data storage RAM 32.

If the program data of the menu program has not yet been received for the currently multiplexed FM multiplex broadcast, C
The PU 30 displays that the menu program is currently being received (step 202), and the user operates the operation unit 40.
It is determined whether or not an instruction to switch the broadcast station to be displayed has been issued by pressing the "broadcast station switching" key (step 20).
3). If the user has not instructed to switch the broadcast station, the display indicating that the menu program is currently being received is repeated until program data on the menu screen is received.

When the user instructs to switch the broadcasting station, the CPU 30 determines whether or not program data of another broadcasting station is stored in the data storage RAM 32 (step 204). If the program data of another broadcasting station is not stored in the data storage RAM 32, it is displayed that the menu program is currently being received until the program data of the menu screen of the currently received FM multiplex broadcast is received. Is repeated.

On the other hand, as shown in FIG. 14, when the program data of another broadcast station is stored in the data storage RAM 32, the program data of another broadcast station stored in the data storage RAM 32 is stored. (If program data corresponding to a plurality of broadcast stations is stored, the program data corresponding to any of the broadcast stations is extracted), and whether or not the extracted program data includes the menu screen program data is determined. Is determined (step 205).

When the data saving RAM 32 contains the menu screen program data (when an affirmative decision is made in step 205), or when the menu program data is received for the currently multiplexed FM multiplex broadcast ( If a positive determination is made in step 201),
CPU 30 reads out the program data of the menu program from data storage RAM 32 and displays the contents (step 206). FIG. 16 is a diagram illustrating an example of the display of the menu program. As shown in the figure, a program type such as news or traffic information is displayed in the menu program.
When the menu program is displayed over a plurality of pages, the user can switch pages by pressing a “page forward” key or a “page back” key of the operation unit 40.

Next, the CPU 30 allows the user to operate the operation unit 40.
Is depressed to determine whether a program to be displayed is selected from the menu screen (step 20).
7). When any program is selected from the menu screen in this way, or when the data storage RAM 32
If the program data corresponding to any one of the broadcast stations stored in the program data does not include the program data corresponding to the menu screen (if a negative determination is made in step 205),
CPU 30 displays the contents of a predetermined program (step 208).

For example, when the menu key shown in FIG. 16 is displayed and the user presses the numeric keypad "1" and selects "news", the corresponding news program is displayed. Such display of the program contents is performed irrespective of whether the program to be displayed corresponds to the currently received FM multiplex broadcast or stored in the data storage RAM 32. Since data other than the program data of the program type specified in advance is not stored in the data storage RAM 32, when a program of the program type not stored is selected from the menu screen, for example, “Data is stored. And cannot be displayed because it is not displayed. " If a menu program is not included (if a negative determination is made in step 205), any of the program data stored in the data storage RAM 32 corresponding to the program type specified in advance is selected. The data is read and its contents are displayed.

In parallel with the program content display operation thus performed, the CPU 30 determines whether or not the user has pressed the “menu program display” key of the operation unit 40 to instruct switching to the menu screen display. (Step 209),
It is determined whether the user has pressed the "broadcast station switching" key and instructed to switch the broadcast station to be displayed (step 21).
0). When switching to the menu screen display is instructed, the processing after step 206 (menu screen display operation) is repeated. When switching of the broadcasting station is instructed, the CPU 30 determines whether or not the switching is to the broadcasting station that is currently broadcasting the currently received FM multiplex broadcast (step 211). When switching to the broadcasting station currently receiving FM multiplex broadcasting is instructed, the processing after step 201 (operation for determining whether or not a menu program has been received) and thereafter are repeated, and the data storage RAM 32
If an instruction to switch to a broadcast station corresponding to the program data stored in is stored, the processing after step 204 (operation for determining whether or not data of another broadcast station is stored in the data storage RAM 32) is performed. Is repeated.

As described above, when the receiving frequency is changed, the FM multiplex broadcasting receiver 1 of the present embodiment stores the program data corresponding to the program type designated in advance without deleting it from the data storage RAM 32. Has been continued,
The stored program data can be displayed at any time. Therefore, even immediately after the reception frequency is switched and the menu screen and other program data included in the FM multiplex broadcast of the new reception frequency are not received, the specific data stored in the data storage RAM 32 is not stored. The program of the program type can be displayed, and the time required for displaying useful information can be shortened.

In particular, since only the program data corresponding to the program type specified by the user is stored, only the program data corresponding to the program desired to be viewed is selectively stored without being deleted.
The data storage RAM 32 can be used efficiently.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention. For example, in the above-described embodiment, only the program data corresponding to the program type specified by the user is continuously stored without being deleted, but all the program data is stored without specifying the program type. You may do so.

In the above-described embodiment, the program data corresponding to the designated program type is stored in the data storage RAM 32 by designating the program type in advance. The method of specifying the program data can be changed as appropriate. For example, instead of the user designating a program type in advance, a program type fixedly set in advance may be used, or a program type that the user wants to keep may be designated at an arbitrary timing. Also, by specifying one or more broadcasting stations,
All the program data received from the broadcast station may be stored without being deleted.

Further, in the above-described embodiment, a case is described in which, when the reception frequency of the FM multiplex broadcast is changed, the program data included in the FM multiplex broadcast of the reception frequency before the change is continuously stored without being deleted. However, when the operation state is changed by switching from FM multiplex broadcasting to another operation mode such as AM broadcasting or a CD player, the program data included in the FM multiplex broadcasting before the switching is continuously stored without being deleted. Then, when the display state of another operation mode is switched, or when the operation mode returns to the reception state of the FM multiplex broadcast from another operation mode, the display based on the already stored program data is performed. Is also good.

In the above-described embodiment, the "broadcast station identification" included in the program data is used to distinguish the currently received FM multiplex broadcast program data from the previously received FM multiplex broadcast program data. However, "reception frequency", a series of serial numbers, or the like may be used instead of "broadcasting station identification".

Further, in the above-described embodiment, as for the program data corresponding to the program type designated by the user, all the data received in the past are continuously stored, but it is not always necessary to continuously store all of them. For example, the program data corresponding to the program type designated by the user may be continuously stored only for the FM multiplex broadcast program data received immediately before changing the reception frequency.

[0058]

As described above, according to the present invention, when the receiving state is changed, the multiplexed data of the FM multiplex broadcasting before the change is left without being deleted, and is left after the change. By displaying the contents of the multiplexed data that has been stored, the contents of the multiplexed data that has been maintained in the storage state without being deleted can be deleted even when the preparation for displaying the new contents performed after the change of the reception state is not completed. The display can be performed, and the time during which no useful information is displayed, that is, the time until the useful information is displayed can be shortened. In addition, by making it possible to designate multiplexed data whose storage state is maintained without being deleted, it is possible to efficiently store data while leaving only multiplexed data required by the user.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of an FM multiplex broadcast receiver according to an embodiment to which the present invention is applied.

FIG. 2 is a diagram illustrating a transmission path signal of a layer 1;

FIG. 3 is a diagram showing a frame structure corresponding to layer 2;

FIG. 4 is a diagram showing the structure of a data packet of layer 3;

FIG. 5 is a diagram showing the structure of a data group for sending character / graphic information of layer 4;

FIG. 6 is a diagram showing a structure of a data group for transmitting additional information of layer 4;

FIG. 7 is a diagram illustrating a structure of program data of a hierarchy 5;

FIG. 8 is a diagram showing an example of data header data included in a data header of program management data.

FIG. 9 is a diagram illustrating an example of data header data included in a data header of page data.

FIG. 10 is a diagram showing the contents of each data unit constituting a data unit group.

FIG. 11 is a diagram showing a structure of a segment of a hierarchy 5;

FIG. 12 is a diagram illustrating an example of segment identification.

FIG. 13 is a flowchart showing an operation procedure of receiving program data in the FM multiplex broadcast receiver of the present embodiment.

FIG. 14 is a diagram illustrating an example of data stored in a data storage RAM.

FIG. 15 is a flowchart showing an operation procedure of displaying program data in the FM multiplex broadcast receiver of the present embodiment.

FIG. 16 is a diagram showing an example of display of a menu program.

[Explanation of symbols]

 Reference Signs List 1 FM multiplex broadcast receiver 12 Front end (F / E) 14 Intermediate frequency amplification / FM detection circuit (IF / DET) 18 Filter circuit 20 LMSK demodulation circuit 24 Error detection and correction circuit 30 CPU 32 Data storage RAM 36 Display unit 38 Tuning circuit 40 Operation unit

Claims (8)

[Claims] 1. A plurality of FMs corresponding to different reception frequencies
An FM multiplex broadcast receiver for receiving and storing multiplexed data included in each of multiplex broadcasts, wherein at a time of changing a reception frequency, at least a part of the multiplex data corresponding to the FM multiplex broadcast of the reception frequency before the change. An FM multiplex broadcast receiver which maintains the storage state and displays the content of the multiplexed data in which the storage state is maintained when receiving the FM multiplex broadcast of the changed reception frequency. 2. A plurality of FMs corresponding to different reception frequencies
An FM multiplex broadcast receiver for receiving and storing multiplexed data included in each of the multiplex broadcasts, a data receiving means for receiving the FM multiplex broadcast and extracting the multiplexed data included therein, and the data reception Data storage means for storing the multiplexed data extracted by the means, content display means for displaying the contents of the multiplexed data stored in the data storage means, and when the operation state by the data receiving means is changed. ,
The storage state of at least a part of the multiplexed data stored in the data storage means corresponding to the FM multiplex broadcast before the operation state is changed is maintained, and if there is other multiplexed data, And FM storage multiplexing receiver. 3. The FM multiplex broadcast receiver according to claim 2, wherein the change of the operation state by the data receiving means is a change of a reception frequency. 4. The FM multiplex broadcast receiver according to claim 2, wherein the change of the operation state by the data receiving means is a stop of the reception operation. 5. The data specifying unit according to claim 2, further comprising a data specifying unit that specifies multiplexed data whose storage state is maintained in the data storage unit when an operation state of the data receiving unit is changed. The FM multiplex broadcasting receiver, wherein the storage control means deletes multiplexed data other than the multiplexed data specified by the data specifying means from the data storage means. 6. The data storage means according to claim 2, wherein the data storage means stores multiplexed data corresponding to each FM multiplex broadcast having a different reception frequency. FM reading the multiplexed data stored in the storage means for each FM multiplex broadcast having a different reception frequency and displaying the content.
Multiplex receiver. 7. The storage device according to claim 5, wherein when the FM multiplex broadcasting corresponds to the data radio channel system, the storage control unit determines whether or not the multiplexed data is the multiplexed data specified by the data specifying unit. The FM multiplex broadcast receiver is characterized in that the determination is made based on the data identification and the program number corresponding to the multiplexed data. 8. The data multiplexing apparatus according to claim 6, wherein when the FM multiplex broadcasting corresponds to the data radio channel system, the data storage means multiplexes the broadcasting in correspondence with the broadcasting station identification information extracted from the multiplexed data. An FM multiplex broadcast receiver for storing encoded data.