JPH11234593A - Label display method for radio receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To display proper information by discriminating whether or not character information other than service contents is sent by a service label. SOLUTION: A conversion section 30 monitors up to the time when contents of a received service label change so as to discriminate whether the service label indicates character information or substantial service contents, based on whether or not the content-change time is larger than a set time. When the contents indicate the substantial service contents, they are displayed on a display section 29. When the contents are character information, they are displayed according to the instruction of the user (ON/OFF of a character information displays witch CDS). In the case that the service label denotes the character information during driving, the character information is not displayed but reception frequency or the like is displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a label display method for a radio receiver, and more particularly to a label display method for a radio receiver that extracts and displays a service label included in a digital broadcast signal or a data multiplex broadcast signal.

[0002]

2. Description of the Related Art Digital audio is now widely recognized for its excellent characteristics and ease of use, and is rapidly becoming popular. Against this background, digitalization of audio broadcasting has become active and digital audio broadcasting DAB (Digital Audio Broadcasting) has been realized in Europe.

FIG. 6 shows a mode II DAB broadcast signal frame structure employed in a DAB system. One frame length is 24 ms, and a two-symbol synchronization part SYNC is used.
And FIC (Fast Inf)
or the main service channel (MSC) of 72 symbols. The synchronization unit SYNC includes a null symbol and a phase reference symbol PRS used for recognizing a start point of a frame.
Contains. The high-speed information channel unit FIC includes three-symbol high-speed information blocks FIB1 to FIB3, and includes various information such as a service label, service arrangement data, and a program type code PTY (Program type code).

The main service channel MSC is divided into 72 data fields (symbols), a broadcast signal of a predetermined service (program) is inserted into each data field, and 6 to 8 services (simultaneously) are transmitted from one broadcasting station. Program) can be transmitted. Which service corresponds to which data field is specified by the service array data included in the high-speed information channel unit FIC. Each high-speed information block FIB1 to FIB3 of the high-speed information channel FIC has a hierarchical structure as illustrated, and is specified by FIG type 131 and extension 141.
Predetermined data is inserted into the datafield 142. That is, each of the high-speed information blocks FIB1 to FIB3 is
6-bit (30-byte) FIB data field
ld) Consists of 111 and CRC 112, FIB data field 111
Is configured to include a plurality of FIG (Fast Information Group) 121-123.

Each FIG (Fast Information Group) 121-12
3 is composed of (1) FIG type (FIG type) 131, (2) Length (byte length of FIG data field) 132, and (3) FIG data field 133, and FIG 1
41 (extended identification number of FIG) and data field 142 are included. In the data field 142, the service label, service arrangement data, program type code PTY, supported announcement types, frequency information list for each area, broadcast station list for each area, broadcast station information during the same program broadcast (service linking Information) is inserted.

For example, service label information is inserted into a data field of FIG1 / 1 (Type 1 field for extension 1) as shown in FIG. FIG1 / 1 (Type 1 field for e
The data field specified by xtension 1) is a 16-bit service identifier (Ser
vice identifier), a character field 202 that displays a 16-word service label (1 word / 8 bit), a 16-bit character that indicates the character position used when a 16-word service label is abbreviated to 8 words A flag field 203 is provided. Therefore, a service label (a label indicating a broadcast station name or a service content) is inserted into the high-speed information channel FIC of the DAB broadcast signal and transmitted, and the DAB receiver extracts the service label included in the received DAB broadcast signal by extracting the service label. It can be appropriately displayed on the display unit. A service label can be described in a maximum of 16 words, but a shorthand notation of up to eight characters can also be made using shorthand character position information sent together with the label.

In DAB broadcasting, character information (dynamic label) can be multiplexed and sent. That is, as shown in FIG. 8, a PAD field is provided at the end of a DAB audio frame every 24 msec, and character information can be inserted into the field and transmitted. In FIG. 8, reference numeral 251 denotes MPEG audio data of a predetermined service; 252, a 2-byte F-PAD field;
Is a scale factor (ScF-CRC) field in which the gain (scale factor) of the variable gain amplifier is written, and 254 is an X-PAD field in which character information is inserted. The X-PAD does not exist (00), the 4-byte short X-PAD exists (01), and the variable length variable-size X-PAD exists (10) according to the predetermined two bits of the F-PAD. Another is shown. The X-PAD is included at the end of a plurality of audio frames in units of 24 msec, and constitutes one meaningful application (character information) by combining several X-PADs.

[0008]

As described above, the DAB broadcasting station can display the name of the broadcasting station and the contents of the service on the DAB receiver by inserting the service label into the FIC of the DAB signal and transmitting it. . However, depending on the DAB broadcasting station, there is a possibility that character information such as a weather forecast and news will be sent using a service label that should indicate the contents of the program service regardless of the X-PAD. This is because such character information transmission is performed in RDS radio broadcasting in Europe. Since the RDS radio receiver can display the program service label in units of eight characters, when the contents of the program service label change, the display is performed as changed. For this reason, when character information such as weather forecast and news is sent in the service label, the RD
The S radio receiver changes the display content in units of eight characters. However, while labels such as broadcast station names and service contents that do not frequently change should be displayed, it is not preferable that labels change frequently. In particular, in the case of an in-vehicle receiver, it is necessary to take into consideration the safety during traveling and to prevent the display contents from changing frequently during traveling. DA
Similarly to the RDS radio receiver, when the character information is transmitted with the service label, the B receiver frequently changes the display content in units of 16 characters, which is not preferable. In view of the above, it is an object of the present invention to determine whether character information other than the original service content is being transmitted in a service label in DAB broadcasting or RDS data multiplex broadcasting, and if character information is being transmitted, follow the user's instruction. An object of the present invention is to provide an appropriate display and not to display character information during traveling, thereby improving safety during traveling.

[0009]

According to the present invention, there is provided a label display method for a radio receiver for extracting and displaying a service label included in a digital broadcast signal or a data multiplex broadcast signal. Monitor the time until the content of the service label changes, (2) determine whether the service label is textual information or the original service content based on the change time and the magnitude of the set time, 3) This is achieved by displaying the original service content and displaying the text information in accordance with the user's instruction. If the original service content is sent with an 8-character or 16-character service label, the content of the service label does not change frequently. However, when the character information is sent by the service label, the character information is 16 characters or more, and the content changes in a short time. Therefore, by monitoring the change time of the received service label, whether the service label is character information or
It is possible to determine whether the service is the original service content. If the service content is the original service, it is displayed. If the information is character information, an appropriate display according to the user instruction is performed. For example, if the information is character information, the reception frequency is displayed without performing the display.

When the service label is character information, the character information is not displayed if the vehicle is traveling, but the received frequency is displayed instead. If the service label is stopped, the received character information is displayed. With this configuration, even if character information is received during traveling, the display does not change frequently, so that traveling safety can be improved. In addition, character information can be displayed while the vehicle is stopped. In this case, the latest information can be immediately obtained by storing the character information received during traveling and displaying the information when the vehicle is stopped.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (A) Configuration of DAB Receiver FIG. 1 is a configuration diagram of a DAB receiver according to the present invention. 21a,
21b is an antenna, 22a is AM from AM / FM station
/ 1 that receives FM broadcast signals and converts them to intermediate frequency signals
The tuner unit 22b is a second tuner unit that receives a DAB signal from a DAB station and converts it into an intermediate frequency signal. Each of the tuners 22a and 22b includes a front end provided with a tuning unit, a high-frequency amplifier, and a frequency converter (not shown), and a PLL (local oscillation circuit) that outputs a frequency signal corresponding to a selected frequency. An AM / FM broadcast demodulation unit 23 demodulates and outputs an AM / FM broadcast signal.
3a is an IF filter, 23b is a detection circuit for demodulating an audio signal from an intermediate frequency signal, 23c is connected to the S meter terminal of the IF filter, and is an S meter for detecting the reception electric field strength of the AM / FM broadcast signal being received, 23d Is an RDS decoder that outputs RDS data multiplexed on the FM signal.

Reference numeral 24 denotes a DAB broadcast demodulation unit for demodulating a broadcast signal of the program from a frequency multiplexed signal inserted in a data field (symbol) corresponding to a designated program (service) and outputting the demodulated signal. DAB broadcast demodulator 24
, 24a is a DAB IF filter, 24b is a DAB signal demodulation unit, 24c is a DA converter that converts PCM audio data to analog, 24d is connected to the S meter terminal of the DAB IF filter 24a, This is an S-meter for detecting the reception electric field strength (reception state) of a broadcast signal. The DAB signal demodulation unit 24
B signal demodulation function, demodulated high-speed information channel F
A function of inputting various information included in the IC to the control unit 30;
It has a function of demodulating an MPEG audio signal corresponding to a program specified by a user, a function of converting an MPEG audio signal into PCM audio data, and outputting the same.

A selection unit 25 selects and outputs an output signal of the AM / FM broadcast demodulation unit 23 and an output signal of the DAB broadcast demodulation unit 24 as appropriate, 26 a low-frequency amplifier, 27 a speaker,
Reference numeral 28 denotes an operation unit provided with various keys, including a character information display switch CDS, a band switching key, a seek key, a program selection key, and the like; 29, a display unit;
Is a control unit that controls the entire radio receiver, and 31 is a sensor that detects when the vehicle is running. The control unit 30 performs various controls such as electronic tuning / seek control of each tuner and service label display control based on the channel selection operation.

When the FM band is selected on the operation unit 28 and the seek key is operated, the control unit 30 performs electronic tuning / seek control on the first tuner unit 22a, and the FM station whose received electric field strength is equal to or higher than the set level is set. And tunes to the FM station frequency using the first tuner section. Further, the control unit 30 notifies the selection unit 25 that the FM station has been selected. The first tuner unit 22a converts the sought FM broadcast signal into an intermediate frequency signal, the AM / FM broadcast demodulator 23 demodulates the FM audio signal from the intermediate frequency signal, and the selector 25 selects the FM audio signal. And output.
In this case, if the RDS data is multiplexed on the FM broadcast signal, the RDS decoder 23d decodes the RDS data and inputs it to the control unit 30, and the control unit 30 performs various controls based on the RDS data.

On the other hand, when the DAB band is selected on the operation unit 28 and then the seek key is operated, the control unit 30 performs electronic tuning / seek control of the second tuner unit 22b, and the DAB band whose received electric field strength is equal to or higher than the set level is set. The station is searched, and the second tuner is tuned to the DAB station frequency. Further, the control unit 30 notifies the selection unit 25 that the DAB station has been selected. The second tuner unit 22b receives the frequency-division multiplexed broadcast signal from the DAB station that has been sought and converts it into an intermediate frequency signal. The DAB signal demodulation unit 24b demodulates the DAB signal from the intermediate frequency signal input from the tuner, and inputs the contents of the high-speed information channel FIC to the control unit 30.

The control unit 30 provides a service (program) based on the service arrangement data included in the high-speed information channel FIC.
The name is displayed on the display unit 29, and the symbol position (data field) of the service selected by the user is notified to the DAB signal demodulation unit 24b. The DAB signal demodulation unit 24b decodes the decoded data (MPE) of the notified symbol (data field).
G audio data) to PCM data,
The M data is input to the DA converter 24c. The DA converter 24c converts the PCM data into an analog signal,
The selector 25 selects and outputs an audio signal output from the DA converter 24c. Thereafter, the DAB signal demodulation unit 24b transmits the information of the high-speed information channel unit FIC to the control unit 3.
The control unit 30 performs various controls based on the information, for example, performs label display control, and displays the service label and character information on the display unit 29 as appropriate.

(B) Label Display Control (b-1) Identification Process for Determining Whether a Program Service Label is Character Information FIG. 2 is a flowchart of identification processing for determining whether a program service label is character information. The control unit 30 monitors whether the program service label has been received (step 30).
1) If received, the received service label is compared with a service label (storage service label) stored in a built-in label storage buffer (step 302). If the received service label is different from the stored service label, the received service label is stored in the label storage buffer (step 303), and thereafter, it is checked whether the timer is below the threshold level (step 304).

The timer is the elapsed time from the previous time when the reception service label differs from the storage service label to the current time. If the timer is equal to or less than the threshold level, it is determined that the service label is character information. That is, if the 16-character service label is the original broadcast station or service content, the content does not change frequently. However, if the service label is textual information, it will be 16 characters or more, and the content will frequently change in a short time. Therefore, if the timer value, that is, the change time of the service label is short, it is determined that the service label is character information, and if the change time is large, it is determined that the service label is new service content different from the past. As described above, if the timer is equal to or lower than the threshold level, the timer is reset to 0 (step 305), and the character information flag is set to "1" to store that the service label is character information (step 305). 306), return to the beginning.

In step 304, if the timer is equal to or higher than the threshold level, the service label has a new service content different from the conventional one as described above. Therefore, the timer is reset to 0 (step 307),
Next, the character information flag is cleared to "0", the fact that the service label is not character information (it is an original service label) is stored (step 308), and the process returns to the beginning.
On the other hand, if the received service label and the stored service label match in step 302, it is checked whether the timer is equal to or higher than the threshold level (step 30).
9). Here, the timer is the elapsed time from the previous time when the reception service label and the storage service label are different to the current time. If the timer is equal to or higher than the threshold level, the service label has not changed its content for a long time, indicating the original service content. Therefore, the character information flag is cleared to "0", the fact that the service label is not character information (it is an original service label) is stored (step 308), and the process returns to the beginning. Step 30
In step 9, if the timer is equal to or lower than the threshold level, it cannot be specified whether or not the service label is character information, so that the process returns to the beginning without operating the flag and repeats the subsequent processing.

(B-2) Processing for Displaying Program Service Label FIG. 3 is a flowchart of processing for displaying a program service label. By the identification process of FIG. 2, the control unit 30 can determine whether the service label is character information or the original service content, and sets or resets a built-in character information flag based on the determination result (step 401). . Next, it is determined whether the character information flag is set, that is, whether the service label is character information (step 402). If the character information flag has been reset (flag = "0"), the DAB broadcast receiver has received the original service content. Therefore, the received service label, that is, the service content is displayed on the display unit 29 as it is.
(Step 403).

On the other hand, if the character information flag is set (flag = “1”), that is, if the service label is character information, the character information display switch C of the operation unit 28
Check if DS is on (step 40)
4) If it is not turned on, the character information is not displayed, and the reception frequency is displayed on the display unit 29 instead (step 4).
05). On the other hand, in step 404, if the character information display switch CDS is turned on, it is checked whether or not the vehicle is currently traveling by referring to the output of the traveling detection sensor 31 (step 406). That is, the character information is displayed on the display unit 29 (step 403). There is no danger even if the character information is displayed unless the vehicle is running. However, when the vehicle is running, when the character information is displayed, the display is frequently switched, and it is dangerous that the user cannot concentrate on driving. Therefore, while traveling, the service label, that is, the character information is not displayed, and the reception frequency is displayed on the display unit 29 instead (step 405).

FIG. 4 is a modification of the processing flow of FIG.
The character information display method differs when the vehicle is not running. In the processing flow of FIG.
Each time a character service label (character information) is received, it is displayed on the display unit 29. However, the 16-character service label is not sent continuously, but is sent intermittently after a predetermined time. Therefore, it is difficult to read the character information. Therefore, it is convenient if character information is stored up to the end of a sentence (punctuation, period) and then displayed continuously at an easy-to-read speed. The modification of FIG. 4 takes such a point into consideration. In FIG. 4, the same steps as those in FIG. 3 are denoted by the same reference numerals. If the character information display switch CDS is on at the time of receiving the character information (YES in step 404), it is checked whether the vehicle is traveling (step 406). If the vehicle is traveling, the reception frequency is displayed on the display unit 29. (Step 405).
On the other hand, if the vehicle is not traveling, the reception service labels are sequentially stored in the built-in memory (step 451). Next, it is checked whether or not a sentence break (punctuation, period) has been received (step 452). If not received, the process returns to the beginning and repeats the subsequent processing. When a sentence break (punctuation, period) is received, the character information stored in the memory is continuously read at a predetermined speed and displayed on the display unit 29 (step 45).
3) After that, the character information stored in the memory is cleared (step 454), and the process returns to the beginning.

(B-3) Another display process of the program service label FIG. 4 shows another flow of the display process of the program service label, in which character information received during traveling is stored and displayed when the vehicle is stopped. The same steps as those in FIG. 3 are denoted by the same reference numerals. If the character information display switch CDS is on when character information is received (Y in step 404)
ES), check whether the vehicle is running (step 40)
6). If the vehicle is running, the reception service label, that is, the character information is not displayed, and is stored in the built-in memory (step 5).
01), a known reception frequency is displayed on the display unit 29 (step 405). In this case, since the size of the memory for storing the reception service label is limited, when the memory becomes full, overwriting is performed so that the latest character information is always stored in the memory.

On the other hand, if the vehicle is not running (stops) in step 406, the character information stored in the memory during running and the character information subsequently received while stopped are displayed on the display unit 29 (step 502). Thereafter, the character information stored in the memory is cleared (step 503), and the process returns to the beginning. The case where the present invention is applied to DAB broadcasting has been described above, but the present invention can also be applied to the case where character information is transmitted with a service label in RDS data multiplex broadcasting or the like. As described above, the present invention has been described with reference to the embodiments. However, the present invention can be variously modified in accordance with the gist of the present invention described in the claims, and the present invention does not exclude these.

[0025]

As described above, according to the present invention, the time until the contents of the received service label changes is monitored, and based on the change time and the set time, whether the service label is character information or not. If the service content is the original service content, it is displayed, and if it is character information, an appropriate display according to the user's instruction, for example, the reception frequency can be displayed. According to the present invention, when the service label is character information, the character information is not displayed when the vehicle is running, the reception frequency is displayed instead, and the received character information is displayed when the vehicle is stopped. Therefore, even if character information is received during traveling, the display does not change frequently, so that safety during traveling can be improved. In addition, character information can be displayed while the vehicle is stopped. In this case, the latest character information received during traveling can be stored, and the information can be displayed immediately when the vehicle stops.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a radio receiver according to the present invention.

FIG. 2 is a processing flow for determining whether a program service label indicates character information.

FIG. 3 is a flowchart of a display process of a program service label.

FIG. 4 is a modified example of the program service label display processing shown in FIG. 3;

FIG. 5 is another display processing flow of a program service label.

FIG. 6 is an explanatory diagram of a frame structure of a DAB broadcast signal.

FIG. 7 is an explanatory diagram of service label information.

FIG. 8 is an explanatory diagram of a PAD field.

[Explanation of symbols]

 22a first tuner unit (for AM / FM) 22b second tuner unit (for DAB) 23 AM / FM broadcast demodulator 24 DAB broadcast demodulator 25 selector 28 operating unit 29 ··· Display unit 30 ··· Control unit 31 ··· Driving detection sensor CDS ··· Character information display switch

Claims (2)

[Claims] 1. A radio receiver label display method for extracting and displaying a service label contained in a digital broadcast signal or a data multiplex broadcast signal, wherein a time until the content of the received service label changes is monitored. It is determined whether the service label is character information or the original service content based on the time and the set time. If the service label is the original service content, it is displayed. A label display method in a radio receiver, which performs display. 2. The label display method for a radio receiver according to claim 1, wherein when the service label is character information, the character information is not displayed while the vehicle is running.