JP2000151438A - Fm multiplex broadcast reception method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an FM multiplex broadcast reception method by which a teletext information program selected by the user is displayed in a short time and where a small memory capacitor is enough. SOLUTION: In the case of receiving FM multiplex data (teletext information) (S21), a program number of received data is compared with a program number of a current program, and when the received data indicate data of the current program (S23: YES), the data are stored in an external memory (S24). On the other hand, when the program number of the received data differs from the program number of the current program (S23: NO), only data by the prescribed number of pages, (e.g. up to first 5 pages) are stored in the memory (S25: YES, S24).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an FM multiplex broadcast receiving method for an FM multiplex broadcast receiver having a character information display function.

[0002]

2. Description of the Related Art In recent years, FM broadcasting stations multiplexed FM broadcasts with weather forecasts, news, traffic information, and information (for example, song titles of music being broadcasted) linked to radio programs being broadcast. Sent as information. Further, an FM multiplex broadcast receiver that receives such information and displays character information on a display screen of, for example, 2.5 lines or 8.5 lines has been commercialized.

There are two types of FM multiplex broadcast receivers, a recording reception type and a standby reception type. In a recording / reception-type receiver, FM multiplexed character information is recorded in a memory, and corresponding information is read out from the memory as appropriate according to a user operation and displayed on a display screen. However, if all of the FM multiplexed character information is to be recorded, the required memory capacity becomes enormous, which makes it difficult to realize. In addition, the amount of data transmitted from a broadcasting station tends to increase year by year. Therefore, in general, data exceeding the memory capacity is truncated.

When a user sets a desired program (text information program), the standby reception type receiver waits until data of the program is transmitted from a broadcasting station. Then, when the data of the set program is transmitted from the broadcasting station, the data of the program is fetched and displayed on the display screen.

FIG. 10 is a schematic diagram showing an example of a hierarchical structure of character information (general information level 1) multiplexed on an FM broadcast. As shown in FIG. 10, the character information multiplexed on the FM broadcast has a hierarchical structure. In this example, there is a main menu on the first hierarchy, and the main menu is linked to submenus A to E on the second hierarchy. In this example, the second hierarchy includes a submenu F that is not linked from the main menu. The submenus B to F are programs B1 to B6, C1 to C6, and D1 to third layer, respectively.
D3, E1 to E5, and F1 to F5. The submenu A is text information linked to the program being broadcast, and the received text information needs to be sequentially displayed on the display unit.

FIGS. 11 (a) to 11 (d) are diagrams showing examples of screen display of an FM multiplex broadcast receiver. However, FIG.
(A) to (d) are display examples in the case of general information level 1 (2.5-line display character information). In this case, the operation of moving to the lower hierarchy (key-in 1 to key-in 1) is provided to the FM multiplex broadcast receiver.
6), an operation of moving to the previous or next page in the same hierarchy (key-in A, B) and an operation of returning to the upper hierarchy (key-in C) are defined. Further, the FM multiplex broadcast receiver is provided with keys corresponding to these operations. For example, FM
The multiplex broadcast receiver has "1" corresponding to key-ins 1 to 6.
There are provided "Page Up" and "Page Down" keys corresponding to the number keys ".about.6", key-ins A and B, and "return" key corresponding to the key-in C.

When the FM multiplex broadcast receiver starts receiving the FM multiplex broadcast, it waits until the information of the main menu is transmitted. For example, as shown in FIG. 11A, the display screen indicates that data is being received. Display a message. In the case of a recording / reception type receiver, information of another layer received during this time is recorded in a memory.

[0008] When the information of the main menu is received, the FM multiplex broadcast receiver displays a main menu screen as shown in FIG. When this screen is displayed, for example, when the numeric key “4” is pressed (key-in 4 is input), the FM multiplex broadcast receiver displays a screen shown in FIG. In this example, it waits until traffic information is received. Then, when the corresponding information is transmitted from the broadcasting station, the information is fetched, and the information shown in FIG.
The acquired information is displayed on the screen as shown in (c).

Here, when the numeric key "1" is pressed (key-in 1 is input), the FM multiplex broadcast receiver is turned on as shown in FIG.
The screen shown in (a) is displayed, and the apparatus waits until the first information (in this example, general expressway) is received. Then, when the corresponding information is transmitted from the FM broadcast station, the information is fetched and the first page of the fetched information is displayed on the screen as shown in FIG. In the case of a recording / reception type receiver, if the corresponding information is already recorded in the memory, the information is read from the memory and displayed on the screen.

[0010]

In the case of a stand-by receiving type receiver, since the program starts to be fetched after the program is specified by the user, there is a disadvantage that it takes time until the information is displayed. Since the frequency at which information is sent is determined for each program, in extreme cases, it may be necessary to wait several minutes to 10 minutes until character information is displayed.

On the other hand, in the case of a conventional recording / reception type receiver, since information is stored in a memory in advance, when a program selected by a user is stored in the memory, character information is displayed in a very short time. can do. However, since the information exceeding the capacity of the memory is truncated, if the program selected by the user is not stored in the memory, it is necessary to wait until the corresponding program is transmitted from the broadcasting station. It takes time to display. If the memory capacity is increased, the data of all programs can be stored, but this increases the product cost.

Accordingly, an object of the present invention is to provide an FM multiplex broadcast receiving method capable of displaying a character information program selected by a user in a short time and requiring a small memory capacity. And

[0013]

SUMMARY OF THE INVENTION An object of the present invention is to provide an FM multiplex broadcast receiving method for receiving FM multiplexed text information, wherein data of each text information program of the same information level is stored in a memory unit in a fixed number of pages. The present invention solves the problem by an FM multiplex broadcast receiving method, which stores a current program set by a user and stores data of a number of pages exceeding the predetermined number of pages in the memory unit.

The operation of the present invention will be described below.

In the present invention, data for a fixed number of pages is stored in the memory unit for each character information program of the same information level. In addition, for a program set by the user (hereinafter referred to as a current program), data for the number of pages (for example, all pages) exceeding the predetermined number of pages is stored in the memory unit. As described above, in the present invention, since data for a large number of pages is stored for the current program, the stored data is read out from the memory unit when page up or page down is instructed, and predetermined information is stored. Can be displayed quickly.

In the present invention, data of a certain number of pages is stored in the memory unit for programs other than the current program. Therefore, even when the user changes the current program, the data is stored in the memory unit. The data can be read and predetermined information can be quickly displayed. When the current program is changed by the user, fetching of data for the missing pages of the program newly designated as the current program (the difference between the number of saved pages of the current program and the number of saved pages of other programs) is started. Is preferred. Thus, the insufficient data can be captured while the stored data is displayed on the display unit.

The predetermined number of pages may be the same for each program, for example, or may be determined according to the total number of pages for each program, such as 30% of the total number of pages for each program.

[0018]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a block diagram showing a configuration of an FM multiplex broadcast receiver for realizing the FM multiplex broadcast reception method according to the embodiment of the present invention. The FM multiplex broadcasting receiver includes an FM receiving unit 1
1, intermediate frequency amplification / detection circuit 12, stereo demodulation circuit 1
3, FM multiplex decoding section 14, control section 15, display section 1
6, operation unit 17, external memory (RAM) 18, and kanji R
OM19.

The control unit 15 is constituted by a microcomputer, and comprises an operation unit 17, an external memory 18, a kanji R
It is connected to the OM 19, the display unit 16, the FM receiving unit 11, and the FM multiplex decoding unit 14. The operation unit 17 includes a channel selection key for setting a reception frequency, numeric keys from “1” to “6” (corresponding to key-ins 1 to 6) for selecting a program of character information, and “page up”. ”Key (corresponding to key-in A),“ page down ”key (key-in B
) And a “return” key (corresponding to key-in C). The control unit 15 sets a reception frequency based on a signal output from the operation unit 17 and selects a program to be displayed on the display unit 16.

In the external memory 18, the control unit 15
Character data to be displayed on the display unit 16 is stored.

The FM receiving section 11 controls the receiving frequency
The FM broadcast is received in accordance with the frequency designated by 5, and is converted into an intermediate frequency signal and output. Intermediate frequency amplification /
The detection circuit 12 amplifies the intermediate frequency signal output from the FM receiving unit 11, and then detects and outputs an FM detection signal. The stereo demodulation circuit 13 stereo-demodulates the FM detection signal output from the intermediate frequency amplification / detection circuit 12 and outputs right channel (R) and left channel (L) audio signals. These audio signals are amplified by an amplifier (not shown) and then supplied to a speaker to drive the speaker.

The FM multiplex decoding unit 14 extracts and decodes FM multiplexed information from the FM detection signal output from the intermediate frequency amplification / detection circuit 12.

The control unit 15 receives the data decoded by the FM multiplex decoding unit 14 and extracts data of a predetermined information level as described later. Then, the extracted data is further classified into data of the current program and data of other programs, and all the data of the current program are stored in the external memory 18.
And the data of other programs are stored in the external memory 18 for a fixed number of pages. The control unit 15 reads data to be displayed on the display unit 16 from the data stored in the external memory 18, converts the data into characters by referring to the kanji ROM 19, and displays the characters on the display unit 16. The display unit 16 has, for example, 2.5
This is a liquid crystal display device capable of displaying rows (60 × 248 dots).

FIG. 2 is a diagram showing a data format of information transmitted by FM multiplexing. In FM multiplex broadcasting, information is transmitted in packet units. One packet is composed of a 32-bit prefix and a 144-bit data block. The prefix includes a 4-bit service identification code, a 1-bit decoding identification flag, a 1-bit information end flag, a 2-bit update flag, a 14-bit data group number, and a 10-bit data packet number.

The service identification code is a code for identifying the provided service, and the value of the service identification code can determine the provided service as shown in FIG. That is, when the service identification code is 1, the general information level is 1.
(Sequential reception), which indicates that the information is linked to the program (music, etc.) currently being broadcast. When the service identification code is 2, it is general information level 1 (recording reception),
It can be seen that the character information is displayed on the display screen for two lines. General information level 2 when the service identification code is 3
(Recording reception), which indicates that the information is character information (including simple figures) displayed on the display screen for eight lines. The traffic information levels 1 to 3 indicated by the service identification codes 4 to 6 are traffic information mainly used in combination with the in-vehicle navigation device.

The decoding identification flag is transmitted to the FM multiplex decoding unit 14.
Indicates a decoding method at the time of decoding, and "1" indicates decoding only in the horizontal direction, and "0" indicates horizontal, vertical, and horizontal decoding. The information end flag indicates whether or not the data group to be transmitted with a certain data group number has ended. When "1", the data group ends, and when "0", other cases are indicated. The data group number is a number assigned to each data group. The data packet number indicates the number of the data packet transmitted for each data group number.

As shown in FIG. 4, one data group is composed of a plurality of (N) data blocks. The data group includes an 8-bit SOH (heading start code), a 7-bit data group size, and a 1-bit DOH.
GL (data group link code), 8-bit data group size, 8-bit × n (n is an integer) data group data, NULL data for length adjustment, 8-bit data group end code, and 16 bits for error correction CR
It is composed of C (Cyclic Redundancy Code).

SOH is a code indicating the start of a data group. The data group header is composed of 7-bit data (data group size) indicating the upper order and 8-bit data (data group size) indicating the lower order.
15 bits indicate the total number of bytes of the data group data. DGL is a code indicating the presence or absence of connection of a data group. When DGL is "1", it indicates that the data group is connected to the next data group, and when DGL is "0", it indicates that there is no connection.

The data group data is a set of information data such as program management data and page data, and one data group usually corresponds to one display unit (one page).

The length adjusting NULL is added as needed between the data group data and the data group end code in order to make the bit length of one data group N times the bit length of the data block.

The data group end code is a code indicating the end of the data group, and the CRC is a code for error detection for each data group.

The data group data is an 8-bit RS.
(Information separating code), 8-bit data header parameter, data header data of arbitrary bits (the number of bits changes depending on the content of the data header parameter), and a plurality of data units. The numerical value of the data header parameter indicates the data header data and the data header length as shown in FIG.

FIG. 6 is a diagram showing the structure of data header data when the data header parameter is 30H, and FIG. 7 is a diagram showing the structure of data header data when the data header parameter is 32H. Data header parameter is 3
When 0H, the data header data includes data of the program number, content update (presence / absence), total number of pages, presentation function (character or graphic, etc.), information type, and display format (level 1 or level 2). It is.

When the data header parameter is 32H, the data header data includes information on the program number, content update (presence / absence), page number, presentation function, information type, display format, header raster color, and raster color. .

FIGS. 8 and 9 are flowcharts showing the operation of the FM multiplex broadcast receiving method according to the present embodiment. In this embodiment, it is assumed that the FM multiplex broadcasting receiver supports only general information level 1. That is, the control unit 15 checks the service identification code (see FIG. 2) of the data decoded by the FM multiplex decoding unit 14, and ignores data whose service identification code is other than 1 or 2. Also, this F
It is assumed that the M multiplex broadcast receiver is set to store the data of the first five pages of each program in the initial state.

When the FM multiplex broadcast receiver starts receiving the FM multiplex broadcast in step S11, it extracts only the data having the service identification code of 1 or 2 and obtains the data of the main menu, as shown in FIG. A menu screen as shown in is displayed. When a desired submenu is selected by the user while the menu screen is displayed, the process proceeds to step S12, where the FM multiplex broadcast receiver receives the data of the submenu and receives the data as shown in FIG. Display the submenu screen. The data of the main menu and the sub-menu are transmitted relatively frequently, and these data can be acquired in a relatively short time.

Next, in step S13, when the user selects a desired program on the submenu screen as the current program, the process proceeds to step S14, where the control unit 15 determines the program number of the selected current program (see FIGS. 6 and 7). ) Is stored in the external memory 18. After that, the FM multiplex broadcast receiver performs the process shown in FIG. 9 every time it receives data with the service identification code of 1 or 2.

That is, when the data having the service identification code of 1 or 2 is received in step S21, the process proceeds to step S22, and the control unit 15 reads the program number of the current program from the external memory 18. Next, step S23
The control unit 15 checks whether the program number of the received data matches the program number of the current program. If they match, the process proceeds to step S24, where the control unit 15 stores the input data in the external memory 18 and ends the process.

On the other hand, if the program number of the data entered in step S23 does not match the program number of the current program, the flow shifts to step S25, where the page number of the received data (see FIG. 7) is set. (In this example, 5
Page). If it is within the set page range, the process proceeds to step S24, where the input data is stored in the external memory 18, and the process ends. If the page number of the received data exceeds the set page range in step S25, the process ends without storing the input data in the external memory 18.

As described above, the control unit 15 executes the above-described processing every time data is received, and stores the data of all pages of the current program and the data of five pages of other programs in the external memory 18. I do. Then, the control unit 15 displays, for example, the data of the first page of the current program on the display unit 16.

When a change of the current program is designated by the user, the control unit 15 reads the data of the first page of the corresponding program from the external memory 18 and displays it on the display unit 16. Then, acquisition of page data for the shortage of the program newly set as the current program is started.

In this embodiment, as described above, for the current program, data for all pages is stored in the external memory 18, and for other programs, the data for the first five pages are stored in the external memory 18. I do. Therefore, when the user views each page of the current program,
What is necessary is just to read data from the external memory 18 and display it on the display unit 16, and each page can be quickly displayed. When the user changes the current program, the control unit 15 reads the data of the first page of the program from the external memory 18 and displays the data on the display unit 16. Then, fetching of the data of the insufficient pages of the program newly set as the current program is started. As a result, the display of the first five pages is quickly switched. Also,
Even if the user does not have the necessary information during the first five pages, the user is taking in the data of the other five pages while viewing the data of the first five pages. Desired data can be displayed in time.

In this embodiment, since the data for the first five pages of each character information program is stored, the capacity of the external memory 18 may be relatively small. For example, in the hierarchical structure shown in FIG. 10, there are a total of thirty programs each including six in each of the five submenus B to F, and the number of pages of each of these programs is 62 pages (specified maximum value). Then, in order to save all pages, a storage capacity for 1860 pages is required. Assuming that the data amount of one page is 256 bytes, a memory capacity of about 500 kbytes is required to store all program pages.

On the other hand, in the present embodiment, the storage capacity for 207 pages (29 programs × 5 pages + 1 program × 62 pages), that is, about 52 kbytes is sufficient, and 100 kbytes is expected even if the amount of information will increase in the future. A sufficient memory capacity is sufficient. Therefore, the size and weight of the FM multiplex broadcast receiver can be reduced, and an increase in product cost can be avoided.

In the above embodiment, data within a page range (for example, 5 pages) designated for each program is stored. However, the number of pages to be stored is set by a ratio to the total number of pages of each program. May be. For example, if the total number of pages is within 30 pages, up to 3 pages, 30 pages
If it exceeds the number of pages, it may be 10% of the total number of pages (however, rounded down).

In the above-described embodiment, the case has been described where the main menu and the sub-menu are displayed and the user specifies the current program and receives data of the current program and other programs. The program number of the current program before turning off is stored in the external memory 18.
And the processing shown in FIG. 9 may be started when the power is turned on.

[0048]

As described above, according to the FM multiplex data receiving method of the present invention, data of each character information program of the same information level is stored for a fixed number of pages, and the current program is stored in the fixed number of times. Since the data for the number of pages exceeding the number of pages is stored, a desired page can be promptly provided to the user even if the capacity of the memory unit is relatively small. As a result, a small and lightweight FM multiplex broadcast receiver can be applied.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an FM multiplex broadcast receiver that realizes an FM multiplex broadcast reception method according to an embodiment of the present invention.

FIG. 2 is a diagram showing a data format of information transmitted by FM multiplexing.

FIG. 3 is a diagram showing service identification codes and their contents.

FIG. 4 is a diagram showing a configuration of a data group.

FIG. 5 is a diagram showing a data header parameter and a data header data length.

FIG. 6 is a diagram showing a configuration of data header data when a data header parameter is 30H.

FIG. 7 is a diagram showing a configuration of data header data when a data header parameter is 32H.

FIG. 8 is a flowchart (part 1) illustrating an operation of the FM multiplex broadcast receiving method according to the embodiment;

FIG. 9 is a flowchart (part 2) illustrating an operation of the FM multiplex broadcast receiving method according to the embodiment;

FIG. 10 is a schematic diagram showing an example of a hierarchical structure of character information multiplexed on an FM broadcast.

FIG. 11 is a diagram showing an example of a screen display of the FM multiplex broadcast receiver.

[Explanation of symbols]

 11 FM receiving section, 12 intermediate frequency amplification / detection circuit, 13 stereo demodulation circuit, 14 FM multiplex decoding section, 15 control section, 16 display section, 17 operation section, 18 external memory, 19 kanji ROM.

Claims (4)

[Claims] 1. An FM receiving FM-multiplexed character information
In the multiplex broadcast receiving method, the data of each character information program having the same information level is stored in the memory unit for a fixed number of pages, and the current program set by the user is stored in a number of pages exceeding the fixed number of pages. An FM multiplex broadcast receiving method, wherein data is stored in the memory unit. 2. The FM multiplex broadcast receiving method according to claim 1, wherein data of all pages of the current program is stored. 3. The FM multiplexing method according to claim 1, wherein when the user changes the current program, the fetching of the data of the missing pages of the program newly designated as the current program is started. Broadcast reception method. 4. The FM multiplex broadcast receiving method according to claim 1, wherein the predetermined number of pages is set for each of the character information programs according to the total number of pages of the program.