JPH07111467A - Multiplex broadcast receiver - Google Patents

Abstract

PURPOSE:To allow a listener to hardly take notice of sound interruption by setting a check interval at random with a random number when all alternative frequency(AF) stations given by an AF list are checked sequentially. CONSTITUTION:A controller 14 checks the reception level of a broadcast wave when a broadcast station of a frequency not present is received. When a detection level is lowered to a level set as an AF check start level, a random number generating routine generates random numbers within a predetermined range. Then as an interval time at random corresponding to the random number elapses, a mute circuit 6 is set ON to mute a voice signal and the check of an AF station is started. When the station is an AF station based on a station dated signal, the frequency and the reception level are stored in the predetermined area of a data memory 17. When the check for all the AF stations is finished in this way, the processing restores to the first step.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiplex broadcast receiver for automatically selecting a broadcasting station in good reception condition which is broadcasting the same program by using RDS data added to FM broadcasting waves.

[0002]

2. Description of the Related Art In FM broadcasting in Europe, RDS data is multiplexed with an audio signal. This RDS data is a collection of digital data relating to program contents and the like, and there are such RDS data as shown in Table 1 below.

[0003]

[Table 1]

As shown in the data structure of FIG. 11, RDS data is repeatedly multiplexed and broadcast with 104 bits (87.6 msec) as a unit. One group consists of four blocks each having 26 bits (21.9 msec), and each block consists of a 16-bit information word and a 10-bit check word + offset word. In addition, each group consists of types 0 to 1 in 4 bits depending on the content.
It is distinguished in 16 ways of 5 and each type (0-15)
On the other hand, two versions A and B are defined respectively, but a PI code (program identification code) is arranged in the first block of all groups.

As shown in FIG. 12, the PI code consists of 16 bits, 1 to 4 bits are a country identification code, 5 to 8 bits are codes indicating a coverage area of a broadcasting station, and 9 to 16 bits are standards of the broadcasting station. It is a broadcasting station identification code indicating a number.

The code representing the cover area is shown in FIG.
As shown in FIG. 3, the 4-bit code is classified into 16 types. Here, the cover area L is a local broadcasting program transmitted from only one broadcasting station, I is an international broadcasting program transmitted to other countries, and N is a national broadcasting program transmitted throughout the country. , S are local broadcast programs transmitted to most of the country,
Is a local broadcast program that is transmitted to only one location and one region. Therefore, 5 in the PI code
By checking the ~ 8-bit cover area code, it is possible to determine that the cover area code is 3h (0011) or more as the local broadcasting station.

Therefore, in a multiplex broadcast receiver utilizing RDS data, the RD contained in the broadcast wave being received.
By extracting the PI code, the AF list, etc. from the S data and storing them in the memory, and when the reception state of the broadcast wave being received deteriorates, by using the AF list, the PI code, etc. stored in the memory, It is possible to switch to another broadcasting station that is broadcasting the same program and has a good reception state (automatic tracking).

The following three methods are well known as automatic tracking methods. The first method is the AF list and PI obtained from the RDS data included in the broadcast wave of the current receiving station.
The code is stored in the memory in advance, and when the reception condition of the current receiving station is relatively good, the reception levels of the broadcast waves of the frequencies given in the AF list are checked in order, and the reception of the checked broadcast waves is received. The levels are stored in the memory, and when the reception level of the current receiving station drops below a certain level, the broadcast waves are received in the order of the reception levels stored in the memory, and the PI code is the PI code stored in the memory. In this method, the station of the matching broadcast wave is set as a new receiving station.

In the second method, the AF list and the PI code obtained from the RDS data included in the broadcast wave of the current receiving station are stored in the memory in advance, and the receiving level of the current receiving station drops below a certain level. At this time, the reception level and the PI code of the broadcast wave of the frequency given in the AF list are sequentially checked, and the reception level is a certain level or more and the PI code matches the PI code stored in the memory. This is a method of selecting a wave station and setting it as a new receiving station.

In the third method, the AF list and PI code obtained from the RDS data included in the broadcast wave of the current receiving station are stored in a memory in advance, and the reception level of the broadcast wave of the frequency given by the AF list is stored. And the PI code are checked in order, the reception level of the broadcast wave in which this PI code matches the PI code stored in the memory is stored in the memory, and when a predetermined key operation is performed, the memory is stored for each key operation. This is a method of selecting the above-mentioned broadcast waves in the order of the reception levels stored in the above and setting them as new receiving stations.

On the other hand, conventionally, in a multiplex broadcast receiver having a preset function, the frequency of a broadcasting station being received in a predetermined area of the memory corresponding to the preset key and the RDS data included in the broadcast wave are acquired. AF list, P
Store I code etc. as preset station data,
When the preset station is called with the preset key,
There is a configuration in which a station having the best reception state is selected by using an AF list, a PI code, etc., and the same broadcast program as the preset broadcast program can be heard. In this type of multiplex broadcast receiver, when the preset station is called, the frequency of the preset station stored in the memory and its A
If the PI code of the broadcast wave of the frequency given in the F list is checked, and the PI code cannot be acquired from any broadcast wave, or any PI code acquired from the received broadcast wave is in a predetermined area of the memory corresponding to the preset key. When it does not match the PI code stored in, the PI seek is performed over the entire frequency range.

[0012]

In any of the above-described automatic tracking methods, since the audio mute is turned on when checking the reception level of the broadcast wave of the frequency given in the AF list, the silent state is maintained during that time. Become. The time required to check each broadcast wave is generally a very short time (for example, 5 to 10 msec), but in the conventional multiple broadcast receiver equipped with the automatic tracking function, the broadcast waves of the frequencies given in the AF list are sequentially ordered. Since the time interval when checking is constant (for example, 2 seconds), especially when the broadcast being received is music, the sound interruption during the check occurs at regular intervals, which makes it easier for the listener to notice the sound interruption. Cause discomfort to.

On the other hand, in the multiplex broadcast receiver having the preset function, at the time of PI seek, a seek operation (one or two rounds) is performed over the entire frequency range until a broadcast wave having a matching PI code is found. However, it generally takes 15 to 30 seconds, and during that period, a mute state occurs due to audio mute, which makes the listener feel uncomfortable.

Therefore, an object of the present invention is to provide a multiplex broadcasting receiver capable of automatically selecting a broadcasting station which is broadcasting the same program and has a good reception condition while minimizing the discomfort given to the listener. Especially.

[0015]

In order to solve the above problems, the invention according to claim 1 stores the AF list and PI code acquired from the RDS data included in the broadcast wave of the current receiving station in a memory, The reception level of the broadcast wave of the frequency given in the AF list is checked in order, the checked reception level of the broadcast wave is stored in the memory, and when the reception level of the current receiving station falls below a certain level, it is stored in the memory. Receive the above broadcast waves in the order of stored reception levels,
A multiple broadcast receiver having a station of a broadcast wave whose PI code matches the PI code stored in the memory as a new receiving station, is provided with a random number generation means, and according to an arbitrary numerical value given by this random number generation means. It is characterized in that the time interval for checking the broadcast wave given in the AF list is set at random.

In order to solve the above-mentioned problems, a second aspect of the present invention is provided.
The described invention stores the AF list and PI code acquired from the RDS data included in the broadcast wave of the current receiving station in the memory, and when the reception level of the current receiving station drops below a certain level, The reception level of the broadcast wave of the given frequency and the PI code are checked in order, and a new station of the broadcast wave whose reception level is above a certain level and whose PI code matches the PI code stored in the memory is newly received. In the multiplex broadcast receiver serving as a station, random number generation means is provided, and the time interval for checking the broadcast wave given in the AF list is set randomly according to an arbitrary numerical value given by the random number generation means. To do.

Further, in order to solve the above-mentioned problems, a third aspect of the present invention is provided.
According to the described invention, the frequency of the received broadcast wave and the AF list, the PI code, etc. acquired from the RDS data included in the received broadcast wave are stored in the predetermined area of the memory in a predetermined area of the memory in correspondence with the preset key. When a preset station is called by operating a key or another predetermined key, the reception level and the PI code of the broadcast wave of each frequency stored in the predetermined area of the memory are sequentially checked, and the reception level is equal to or higher than a certain level. In a multiplex broadcast receiver that tunes a broadcast wave whose PI code matches the PI code stored in the predetermined area of the memory, the PI code of any broadcast wave checked is the PI code stored in the predetermined area of the memory. If it does not match with the specified part of the PI code for country identification and broadcasting station identification,
It is characterized by checking whether or not the PI code of each broadcast wave matches the PI code stored in a predetermined area of the memory, and selecting the broadcast wave in which the specific part of the code matches.

According to a fourth aspect of the present invention, in the multiple broadcast receiver according to the third aspect, the PI code comprises 16 bits, of which 1 to 4 bits form a country identification code.
~ 8 bits form the coverage area code of the broadcasting station, 9 ~
If 12 bits and 13 to 16 bits form a broadcasting station identification code and the country identification code stored in a predetermined area of the memory indicates a predetermined country, the country identification code of the PI code is 1 to 4 bits and 9 to 12 bits. If the country code stored in a predetermined area of the memory indicates a country other than the specified country, the 1 to 4 bit country identification code of the PI code is used as the bit broadcasting station code. It is characterized in that a broadcasting station code of 9 to 16 bits is used as the specific part of the code.

According to a fifth aspect of the present invention, in the multiplex broadcast receiver according to the third aspect, the predetermined area of the memory corresponding to the preset key is the frequency of the received broadcast wave (home frequency) at the time of presetting the preset key and this. The first storage area for storing the PI code (home PI code) acquired from the RDS data included in the received broadcast wave, and the frequency (current frequency) of the broadcast wave received by the subsequent automatic follow-up channel selection and this broadcast wave It has a PI code (current PI code) acquired from the included RDS data and a second storage area for storing the AF list, and the PI code and a specific part of the code are checked by checking the home PI code and the current It is characterized in that it is performed for each PI code.

[0020]

In the multiplex broadcast receiver according to claims 1 and 2, by checking the broadcast wave of the frequency given in the AF list, the broadcasting station which is in the good reception state and is broadcasting the same program is automatically detected. You will be able to tune in. Moreover,
The AF is performed according to an arbitrary numerical value given by the random number generation means.
Since the time interval for checking the broadcast wave of the frequency given in the list is set at random, the time interval for the occurrence of sound breaks during the check becomes random, making it difficult for the listener to notice, so the discomfort given to the listener is minimized. Can be suppressed.

In the multiplex broadcasting receiver according to claim 3, when the PI code of each broadcast wave does not match the PI code stored in a predetermined area of the memory, the country identification and the broadcasting station identification of the PI code are identified. It is checked whether or not the PI code of each broadcast wave matches a PI code stored in a predetermined area of the memory with respect to a particular code of the Tune in. In this case, even if the PI codes do not match, there is a relatively high possibility that the same program is being broadcast on a broadcast wave in which some specific codes for country identification and broadcast station identification match. In addition, since the number is limited, it is possible to quickly and automatically select a broadcasting station that is broadcasting the same program and is in a good reception state. Therefore, it is possible to avoid a silent state for a long period of time, and it is possible to minimize discomfort to a listener.

1 to 16 of the 16-bit PI code
There is a high possibility that the same wave is broadcast on the broadcast wave in which the 4-bit country identification code and the 9- to 16-bit broadcasting station code match. However, in countries with many local stations such as the United Kingdom, the same program is broadcast. There is a high possibility that the code of 13 to 16 bits will be different even in the case of a broadcast wave that broadcasts. Therefore, in the multiplex broadcast receiver according to claim 4, together with the country identification code of 1 to 4 bits and the broadcasting station code of 9 to 12 bits of the PI code, 13 to 16 depending on the country identification code.
By selectively using the bit broadcasting station code as a specific part of the checking code, it is possible to quickly select a broadcasting station that is broadcasting the same program in a good reception state with a higher probability.

Frequency and PI stored at preset
If the code is rewritten to the newly acquired PI code by the subsequent automatic follow-up channel selection, etc., it will be included in the broadcast wave depending on the time when it returns to the preset broadcast area after leaving the preset broadcast area. When the PI code changes, it may be impossible to find a broadcast wave having the same PI code, and a situation may occur in which the broadcast wave having the same PI code cannot be received due to PI seek. In the broadcast receiver, the home PI code and the current PI code can be checked for the PI code and a specific part of the code, so that a broadcasting station that is broadcasting the same program in a good reception state can be selected. It will be possible to select a channel quickly with a higher probability.

[0024]

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

FIG. 1 is a principal block diagram showing the structure of a multiplex broadcast receiver according to an embodiment of the present invention. This multiplex broadcast receiver can be used, for example, as a car radio or as a car audio by being integrated with a tape cassette, a deck, or the like. In the figure, 1 is an antenna, 2
Is a front end, which tunes to a predetermined broadcasting station based on the tuning voltage signal output from the PLL circuit 3, and generates an intermediate frequency signal (IF signal). An intermediate frequency amplifier 4 amplifies the IF signal output from the front end 2 to a predetermined level. 5 is a stereo demodulation circuit (MP
X), and demodulates the IF signal input from the intermediate frequency amplifier 4 into a stereo signal. 6 is a mute circuit, and 7 is an amplifier (AMP). 8 is a speaker and amplifier 7
It is driven by and outputs voice.

9 is a 57 KHz bandpass filter (B
PF) and 57 modulated based on RDS data
Pass the KHz subcarrier. An RDS decoder 10 demodulates RDS data from the output of the bandpass filter 9. An RDS data synchronization error correction circuit 11 detects an error in the RDS data demodulated by the RDS decoder 10 while synchronizing each group and corrects the error.

A signal meter 12 detects the received electric field strength using the IF signal output from the intermediate frequency amplifier 3 and outputs a detection signal (SM). 13 is a station detector, which is a high-level station detect signal indicating that a receiving station exists when the received signal is within the frequency deviation Δf (bandwidth) of the received signal and the signal strength is equal to or higher than a predetermined level. (SD = ON) is output. Therefore, the station detect signal SD is low level (S
In the case of D = OFF), even if the signal strength (SM) detected by the signal meter 12 is large, the broadcasting station at the tuning point does not actually exist, and the detected signal strength affects the influence of the adjacent station. Judge that it has been received.

Reference numeral 14 denotes a controller composed of a microcomputer, which includes a processor (CPU) 15, a program memory (ROM) 16 and a data memory (RAM).
It has 17 mag. Reference numeral 18 is an operation unit. Here, the operation unit 18 is provided with six preset keys (# 1 to # 6). The controller 14 executes the program stored in the program memory 16 by the processor 15, fetches the RDS data sequentially input in group units from the error correction circuit 11 and stores it in the data memory 17, and the operation unit 18 Controlling the frequency division ratio of a program frequency divider (not shown) of the PLL circuit 3 based on the command,
The front end 2 is tuned to a predetermined broadcasting station. When traffic information broadcasting is started at a broadcasting station receiving the preset or a broadcasting station of another network, etc.
It is possible to automatically switch from another audio source (not shown) such as a tape to the radio mode by using the P and TA data and listen to the traffic information.

As shown in FIG. 2, in the fixed area 19 of the data memory 17 starting from the address 2000, for example, the frequency (N value) of the broadcasting station being received and the PI code obtained from the RDS data of the broadcasting wave, AF Lists, EON data, etc. are stored. Further, as shown in FIG. 3, a certain area of the data memory 17 starting at addresses 2100, 2200, ..., 2600, etc. corresponds to the preset frequency keys # 1 to # 6, and corresponds to the reception frequency and the RDS of the broadcast wave. The preset station data storage unit 20 stores the PI code, AF list, EON data, etc. obtained from the data. In this embodiment, the preset station data storage unit 20 includes a home memory area 20a and a current memory area 20b, which will be described later. It is divided into and. Further, the frequency of the received broadcast wave and the reception level (S / M) detected by the signal meter 12 can be stored in a predetermined area of the data memory 17 starting from a predetermined address, as shown in FIG. 2 to 4
The data such as the address, frequency, code, etc. shown in are virtual.

Each time the controller 14 inputs the RDS data from the broadcast wave being received, the controller 14 executes the interrupt processing shown in FIG. 5 to acquire PI, AF, etc. from the RDS data, and RD
The PI, AF, etc. of another network broadcasting station are acquired from the EON data in the S data and written in a predetermined area of the data memory 17. For example, if RDS data is input from the broadcast wave during reception of a broadcast station that is not preset, the address of the data memory 17 is based on the RDS data.
PI, AF, EON in the area starting from 2000 (see Fig. 2)
Rewrite data such as. Further, for example, if RDS data is input from the broadcast wave during reception of the broadcast station called by the preset key # 1, the current PI, A of the area starting from the address 2100 of the data memory 17 (see FIG. 3).
Rewrite data such as F and EON.

Next, the automatic follow-up operation, which is a feature of the present invention, will be described. FIG. 6 is a flowchart showing the AF check operation for the automatic tracking process. Referring to the figure, for example, the controller 14 checks the reception level of the broadcast wave during reception of a broadcast station having a frequency of 86.5 MHz which is not preset (step 101). Then, when the detection level of the signal meter drops to, for example, the level 50 set as the AF check start level, the random number generation routine generates a random number within a fixed range corresponding to the range of 1.5 to 4 seconds (step 102). . Then, it waits for a random interval time corresponding to the random number to elapse (step 103), and when this interval time elapses, the mute circuit 6 (see FIG. 1) is turned on (O).
The voice is muted to N) (step 104) and the AF station check described later is started.

That is, when the broadcasting station of the above frequency is being received, the frequency (N value) of the first AF station (N value) from the AF list stored in the fixed area starting from the address 2000 of the data memory 17 (the example of FIG. 2). (83.1 MHz) is read out and a drive signal corresponding to this frequency is given to the PLL circuit 3 (FIG. 1) (step 105). The PLL circuit 3 applies a control voltage (V _T ) to the FM front end 2 in response to this drive signal, and tunes the FM front end 2 to a frequency of 83.1 MHz. The controller 14 waits for a fixed time required for stabilizing the control voltage (V _T ) (step 106), then checks the station detect signal (SD) input from the received broadcast wave (step 107), and SD = ON.
If it is the AF station, the frequency and reception level (S / M) are stored in a predetermined area (see FIG. 5) of the data memory 17 starting from a predetermined address (step 108). afterwards,
Return the received frequency to the original frequency (N value) (step 10
9), the mute circuit 6 is turned off (step 110). Then, it is checked whether all the AF stations in the AF list have been checked (step 11).
1) If the check is not completed, step 10
Return to 2 and check the next AF station. In this way, in the predetermined area of the data memory 17 shown in FIG.
The frequency and reception level (S / M) of the AF station with D = ON are stored in order. In step 111, all AF
When the station check is completed, a predetermined time (for example, 10 seconds) is waited (step 112) and the process returns to step 101.

As is apparent from the above, the check interval for sequentially checking all the AF stations given in the AF list depends on the random number given in the random number generation routine, for example.
Since it is randomly set within the range of 1.5 to 4 seconds, the time interval of sound interruption due to mute during AF check becomes random, and it becomes difficult for the listener to notice the sound interruption. Note that FIG.
If it is determined in step 111 that all AF stations have not been checked, the process may return to step 101.

FIG. 7 shows the operation of automatic follow-up channel selection when the reception level of the receiving station reaches the reception limit level. Referring to the figure, the controller 14 checks the reception level of the received broadcast wave (step 113), and when it falls to the reception limit level (for example, level 30) that requires switching of the reception station, turns on the mute circuit 6 (step 1
14), the reception level (S / S) of the AF stations of SD = ON stored in the predetermined area of the data memory 17 shown in FIG.
The one with the largest M) is read out and its frequency (N value) is set as the reception frequency (step 115). And PL
Waiting for a certain period of time for stabilization of the control voltage (V _T ) given from the L circuit 3 to the FM front end 2 (step 116), and checking the PI code acquired from the RDS data of the received broadcast wave (step 117). ), This PI
When the code matches the PI code stored in the predetermined area of the data memory 17, the mute circuit 6 is turned off.
Then (step 118), the tuning operation is ended. For example, when this tuning process is performed during reception of a non-preset broadcast station having a frequency of 86.5 MHz, the PI code (C201) stored in the memory area shown in FIG. 2 is referred to when checking the PI code. . Further, for example, when this tuning process is performed during reception of a broadcasting station of a frequency of 86.5 MHz called by the preset key # 2, the PI code is checked by checking the current PI code stored in the memory area shown in FIG. (C201) is referenced.

On the other hand, if the PI code does not match the PI code stored in the predetermined area of the data memory in step 117, whether all AF stations stored in the memory area of FIG. 4 have been checked or not. Is checked (step 119), and if the check is not completed, the flow returns to step 115 to perform the PI check of the next AF station. On the other hand, when the PI check of all AF stations is completed in step 119, the process moves to the PI seek process known per se (step 120).

In step 115, the AF stations temporarily stored in the predetermined area (FIG. 4) of the memory are rearranged in order from the highest reception level, and then the AF stations are sequentially processed from the highest reception level. May be read.

FIG. 8 shows another embodiment of the present invention relating to the automatic follow-up operation. The circuit configuration of this embodiment is shown in FIG.
The configuration of the data memory is the same as that of FIG.
And the configuration shown in FIG. Therefore, reference will be made to FIGS. 1-3 for the description of the embodiment of FIG.

In the embodiment shown in FIG. 8, the controller 14
Checks whether the reception level (S / M) of the broadcast wave being received has fallen to the AF check start level (step 201), and when the AF check start level is reached, the random number generation routine causes A random number is generated (step 202). Then, a random interval time corresponding to this random number is set (step 203), and when this interval time has elapsed, the mute circuit 6 is turned on (step 204) to start the AF check. That is, for example, when a broadcast station unrelated to the preset key is received, A is selected from the AF list in the memory area shown in FIG.
Read the frequency (N value) of station F. On the other hand, when the broadcast station associated with any preset key is received, the frequency (N value) of the AF station is read from the AF list in the memory area of FIG. 3 corresponding to the preset key. Then, based on the frequency (N value) of the AF station read from the predetermined AF list in this way, a drive signal is given to the PLL circuit 3 (step 205), and a control voltage (from the PLL circuit 3 to the FM front end 2 ( Wait for a fixed time required for stabilization of V _T (step 206), and after this fixed time, check the input signal of the station detector 13 of the received broadcast wave. If SD = ON, the reception level by the signal meter 12 The detection signal (S / M) is checked (step 207). If SD = ON and the reception level is equal to or higher than the predetermined level, R of the AF station that received
The PI code acquired from the DS data is checked (step 208). For example, when this PI code matches the PI code stored in the memory area of FIG. 2, the mute circuit 6 is turned off (step 209). The process ends.

On the other hand, in step 207 SD = ON
If not, or if the reception level (S / M) of the AF station with SD = ON is below a predetermined level, or if the PI code does not match in step 208, the process proceeds to step 210, and the reception frequency is set to the original frequency ( N value), and the mute circuit 6 is turned off (step 21
1) It is checked whether all AF stations have been checked (step 212). If all AF stations have not been checked, the process returns to step 201. If the AF check start level is still reached, the next AF station is checked after waiting for the random interval time given by the random number generation routine. To start. in this way,
The check interval when sequentially checking all AF stations given in the AF list is randomly set within the range of 1.5 to 4 seconds by the random number given by the random number generation routine. The breaks are randomly spaced, making it difficult for the listener to notice the breaks in the sound. If it is determined in step 212 in FIG. 8 that all AF stations have not been checked, the process may return to step 202.

On the other hand, in step 212, all A
When the check of the F station is completed, it means that the AF station whose SD is ON and the reception level is equal to or higher than the predetermined level and the PI code is the same cannot be found, but in this case, a fixed interval time (for example, 10 (Second) is waited for (step 213) and the process returns to step 201.

Next, a preset function which is another feature of the present invention will be described. In the above embodiment, as shown in FIG. 3, the preset station data storage section 20 of the data memory 17 is divided into a home memory area 20a and a current memory area 20b. For example, the frequency 86.5MHz
If the preset key # 1 is preset while receiving the broadcasting station, the frequency (86.5 MHz) and R are stored in the home memory area 20a corresponding to the preset key # 1.
The PI code (C201) obtained from the DS data is written as the home frequency and the home PI code, respectively.
Further, similarly, in the current memory area 20b, the frequency (86.5 MHz) and the PI code (C201) acquired from the RDS data are respectively set to the current frequency and the current P.
It is written as an I code, and AF data, EON data, etc. are written in the current memory area 20b. In the example of the preset key # 1, the current frequency and the current PI code match the home frequency and the home PI code, respectively. However, the current frequency and the current PI code are set by the later-described channel selection processing at the time of calling the preset. Alternatively, it can be rewritten by the above-described automatic follow-up operation after calling the preset. further,
In France and the like, there are broadcasting stations that send different PI codes depending on the time zone. Therefore, when such a broadcasting station is preset, the current PI code may be rewritten according to the time zone while the preset station is receiving.

Next, the preset calling operation will be described with reference to the flow charts of FIGS. 9 and 10. For example, when the preset key # 1 is called, the controller 14 turns on the mute circuit 6 (step 301) and sets the reception frequency to the home memory area 20a, as shown in FIG.
According to the home frequency (86.5MHz) stored in
After checking the detection signal (SD) of the station detector 13 of the broadcast wave received at this frequency and the reception level signal (S / M) of the signal meter 12, the PI code acquired from the RDS data of this broadcast wave is the home memory area. It is checked whether or not it matches the home PI code (C201) stored in 20a (step 302).

When this PI code does not match the home PI code, the controller 14 adjusts the reception frequency to the current frequency (86.5 MHz) stored in the current memory area 20b and adjusts the broadcast wave received at this frequency. It is checked whether the PI code acquired from the RDS data matches the current PI code (C201) stored in the current memory area 20b (step 3).
03).

When this PI code does not match the current PI code, the controller 14 detects the detection signal (SD) of the station detector 13 and the signal meter 12 for each AF station given in the AF list.
The reception level signals (S / M) are checked in order (step 304). Then, when SD = ON, the reception level (S
If there is an AF station whose / M) is above a certain level, A
After the frequency of the F station is temporarily stored in a predetermined work area (not shown) of the data memory 17, the AF stations stored in the predetermined work area are sequentially called to receive the RDS of the received broadcast wave.
The PI code acquired from the data is checked (step 305). This PI check first refers to the current PI code stored in the current memory area 20b, and when no AF station that matches the current PI code is found, refers to the home PI code stored in the home memory area 20a.

Steps 302, 303, 30 described above
When a broadcasting station having the same PI code is found in 5, the mute circuit 6 is turned on to end the preset station calling process. It is preferable to store the PI code of the received broadcast wave acquired in steps 302, 303, and 305 in a predetermined work area of the memory for related PI check, which will be described later. In this case, mute is turned on in step 306. When these are set, these PI codes are deleted from the predetermined work area.

On the other hand, in step 304, SD = 0
When no N station or an AF station whose reception level (S / M) is a certain level or more is not found, or when an AF station whose PI code matches is not found in step 305, PI seek processing (step 308) is executed. Before, the related PI check processing described later (step 307)
To execute.

FIG. 10 shows the contents of the related PI check processing. Referring to the figure, first, in the related PI check process, the above-mentioned current PI
Check the code and the coverage area code of the home PI code, and if each is a local net station (5 to 8 bits of the PI code is a HEX code, eg, 3 or more), each P
A related PI code is created from the I code (step 40).
1). As described above, the PI code consists of 16 bits, and 1 to 4 bits of which constitute the country identification code, and 5
~ 8 bits form the coverage area code of the broadcasting station, 9 ~
12 bits and 13 to 16 bits form an identification code for each broadcasting station. In the case of a local station in a predetermined country, for example, the United Kingdom, a broadcasting station in which the country identification code (1 to 4 bits) of the PI code and the broadcasting station identification code of 9 to 12 bits match broadcast the same program. In the case of local stations in other countries, the country identification code (1 to 4 bits) of the PI code and the broadcast station identification code (9 to 1)
It is highly possible that broadcast stations having the same 6-bit) are broadcasting the same program. In other words, even in the case of a local station broadcasting the same program, the cover area code consisting of 5 to 8 bits of the PI code is often different, so 5 to 8 bits of the PI code are set as the comparison target of the PI check. If it is included, it is more likely to miss a local station that broadcasts the same program. In addition, for example, in the case of a local station that broadcasts the same program in the UK, the PI code of 13 to 16 bits is often different. Therefore, if 13 to 16 bits are included in the comparison target of the PI check, the same program is included. You are more likely to miss a local station that broadcasts.

Therefore, in the illustrated embodiment, in step 401, the current PI code and home P stored in the preset called memory area are stored.
Regarding the I code, first check the code of 5 to 8 bits, and if it indicates the local station, check the code of 1 to 4 bits, and the code of 1 to 4 bits indicates the specific country such as UK. In some cases, a related P having 1 to 4 bits and 9 to 13 bits respectively as codes for comparison from the current PI code and the home PI code.
An I code is created and stored in a predetermined area (not shown) of the memory. If the 1- to 4-bit code does not indicate a specific country such as the UK, a related PI code having a 1- to 4-bit code and a 9 to 16-bit code as a comparison code from the current PI code and the home PI code, respectively. Is created and stored in a predetermined area (not shown) of the memory.

Next, the reception frequency is set to the current frequency and the PI code of the received broadcast wave is acquired, or the PI code of the current frequency acquired in step 303 of FIG. 9 is read from a predetermined work area of the memory. Read and compare the PI code with the related PI code created from the current PI code (step 402).

If the PI code obtained at the current frequency in step 402 does not match the related PI code, the reception frequency is set to the home frequency and the PI code of the received broadcast wave is obtained, or The home frequency PI code acquired in step 302 is read from a predetermined work area of the memory, and the PI code is compared with a related PI code created from the home PI code (step 403).

Further, when the PI code acquired at the home frequency in step 403 does not match the related PI code, the reception frequency is set to the frequency of the AF station given in the AF list, and the PI code of the received broadcast wave is acquired. Alternatively, the PI code of the AF station frequency acquired in step 305 of FIG. 9 is read from the predetermined work area of the memory, and the PI code is compared with the related PI code TP created from the current PI code. Further, it is compared with the related PI code created from the home PI code (step 404).

If a broadcast station whose PI code matches the related PI code cannot be found in step 404, the related PI check processing is terminated and the PI seek processing (step 308) in FIG. 9 is performed. On the other hand, each step 402,
When a broadcasting station whose PI code matches the related PI code is found in 403 and 404, the process proceeds to step 306 in FIG. 9 to turn on the mute circuit 6 to end the preset calling process.

As described above, since the PI code of each broadcast wave received at the current frequency, the home frequency, and the AF station frequency is compared with the above-mentioned related PI code, it is possible to find a broadcasting station broadcasting the same program. Will increase.

Although the illustrated embodiment has been described above, the present invention is not limited to the embodiment of the above embodiment,
Various changes can be made. For example, as an automatic tracking method, when the AF list and the PI code acquired from the RDS data included in the broadcast wave of the current receiving station are stored in the memory in advance and the reception level of the current receiving station drops to the AF check start level. , The reception level of the broadcast wave of the frequency given in this AF list and the PI code are checked in order, and this PI code is stored in the memory.
The reception level of the broadcast wave that matches the I code is stored in the memory, and when the reception level of the current reception station falls to the reception limit level, the broadcast wave is selected in the order of the reception level stored in the memory. A method of using a new receiving station can also be adopted, and in this case, the time interval of the broadcast wave check given in the AF list is set randomly according to an arbitrary value given by the random number generation routine. Can be configured.

Further, in the above embodiment, the memory area 20 corresponding to the preset key, together with the current memory area 20b, has a preset frequency (home frequency) and P.
Although the home memory area 20a for storing the I code (home PI code) is provided, this home memory area may be omitted to simplify the preset calling process. Further, the preset calling process shown in FIG. 9 and FIG. 10 described above is performed when the preset calling is performed by any one of the plurality of preset keys. However, as a modification of the above embodiment, the preset calling is performed. After being told, F
When the power switch of the M radio is turned off, the preset key called is stored in the memory, and the FM
9 and 1 according to the preset keys stored in the memory when the radio power switch is turned on.
The preset call processing shown in 0 may be performed.

Further, when the present invention is applied to FM / AM radio, or when the present invention is a cassette tape reproducing device,
When applied to an in-vehicle audio device including a compact disc (CD) player, etc., the FM band is switched to the AM band and the F band is switched after the preset calling is performed.
When the sound source is switched from the M radio to the cassette tape, the CD player, etc., the preset key called is stored in the memory in the same manner as in the above modification, so that the AM band is changed to the FM band. When returned,
Alternatively, when the sound source is returned to the FM radio again, the preset calling process shown in FIGS. 9 and 10 may be performed according to the preset key stored in the memory.

Further, although the above embodiment has the automatic follow-up function shown in FIGS. 6, 7 or 8 and the preset calling function shown in FIGS. 8 and 9, the automatic follow-up function shown in FIGS. It goes without saying that the present invention is included in the present invention as long as it is provided with only the function or provided with only the preset calling function shown in FIGS.

[0058]

As is apparent from the above description, according to the first and second aspects of the present invention, when checking the broadcast wave of the frequency given by the AF list, an arbitrary numerical value given by the random number generation means is used. Accordingly, since the time interval for checking the broadcast wave of the frequency given in the AF list is set at random, the time interval for occurrence of sound interruption during the check becomes random, which makes it difficult for the listener to notice. Can be minimized. Therefore,
Provides a multiplex broadcasting receiver that can automatically select a broadcasting station that is broadcasting the same program with a good reception status while minimizing the discomfort to the listener when the reception status of the current receiving station deteriorates. can do.

According to the third aspect of the invention, when the PI code of each broadcast wave does not match the PI code stored in the predetermined area of the memory, the PI code is used for country identification and broadcasting station identification. It is checked whether or not the PI code of each broadcast wave matches the PI code stored in a predetermined area of the memory for some specific code of Since the channel is selected, it is possible to quickly and automatically select a broadcasting station that is broadcasting the same program and is in a good reception state. Therefore,
A multi-broadcast receiver that can avoid a silent state for a long time when calling a preset, and can automatically select a broadcasting station with a good reception condition that is broadcasting the same program while minimizing discomfort to the listener. Can be provided.

[Brief description of drawings]

FIG. 1 is a block diagram of a main part configuration of a multiplex broadcast receiver showing an embodiment of the present invention.

FIG. 2 is a diagram showing a data arrangement structure of a non-preset station data storage unit in the data memory of FIG.

FIG. 3 is a diagram showing a data arrangement structure of a preset station data storage unit in the data memory of FIG.

FIG. 4 is a diagram showing a data arrangement structure of a storage area for storing an AF check result in the NO data memory of FIG. 1;

5 is a flowchart showing an RDS data interrupt input processing operation by the controller of FIG. 1. FIG.

FIG. 6 is a flowchart showing a part of an automatic tracking processing operation by the controller of FIG.

FIG. 7 is a flowchart showing another part of the automatic tracking operation related to the operation of FIG.

8 is a flowchart showing another embodiment of the automatic tracking processing operation by the controller of FIG.

9 is a flowchart showing a part of a preset station call processing operation by the controller of FIG. 1. FIG.

10 is a flowchart showing the contents of the related PI check process shown in FIG.

FIG. 11 is an explanatory diagram showing a data format of RDS data.

FIG. 12 is an explanatory diagram of a bit configuration of a PI code.

FIG. 13 is an explanatory diagram showing types of broadcast station cover area codes in the PI code.

[Explanation of symbols]

 14 controller 15 processor 16 program memory 17 data memory 18 operation unit 19 non-preset station data storage unit 20 preset station data storage unit 20a home memory area 20b current memory area # 1 to # 6 preset keys

Claims (5)

[Claims] 1. An AF list and a PI code acquired from RDS data included in a broadcast wave of a current receiving station are stored in a memory, and reception levels of broadcast waves of frequencies given in the AF list are sequentially checked, The reception level of the checked broadcast wave is stored in the memory, and when the reception level of the current receiving station falls below a certain level, the broadcast waves are received in the order of the reception level stored in the memory, and the PI code is stored in the memory. In a multiplex broadcast receiver having a station of a broadcast wave that matches the existing PI code as a new receiving station, random number generating means is provided, and the AF list is given in accordance with an arbitrary numerical value given by the random number generating means. A multi-broadcast receiver characterized in that the time intervals for checking broadcast waves are set randomly. 2. The AF list and PI code acquired from the RDS data included in the broadcast wave of the current receiving station are stored in a memory, and when the reception level of the current receiving station drops below a certain level, the AF list is displayed. The reception level of the broadcast wave of the given frequency and the PI code are checked in order, and a new station of the broadcast wave whose reception level is above a certain level and whose PI code matches the PI code stored in the memory is newly received. In the multiplex broadcast receiver serving as a station, random number generation means is provided, and the time interval for checking the broadcast wave given in the AF list is set randomly according to an arbitrary numerical value given by the random number generation means. Multiple broadcast receiver to do. 3. A preset key is stored in a predetermined area of the memory corresponding to a preset key by storing the frequency of the received broadcast wave and the AF list, PI code, etc. acquired from the RDS data included in the received broadcast wave in the predetermined area of the memory. When a preset station is called by operating a key or another predetermined key, the reception level and the PI code of the broadcast wave of each frequency stored in the predetermined area of the memory are sequentially checked, and the reception level is equal to or higher than a certain level. In a multiplex broadcast receiver that tunes a broadcast wave whose PI code matches the PI code stored in the predetermined area of the memory, the PI code of any broadcast wave checked is the PI code stored in the predetermined area of the memory. If it does not match with the specified part of the PI code for country identification and broadcasting station identification,
Multiplexing characterized by checking whether or not the PI code of each broadcast wave matches the PI code stored in a predetermined area of the memory, and selecting the broadcast wave in which the above-mentioned specific partial code matches. Broadcast receiver. 4. The PI code consists of 16 bits, of which 1 to 4 bits form a country identification code, 5 to 8 bits form a broadcast station cover area code, and 9 to 12 bits and 13 to 16 bits. Is a broadcasting station identification code, and when the country identification code stored in a predetermined area of the memory indicates a predetermined country, the 1 to 4 bit country identification code of the PI code and the 9 to 12 bit broadcasting station code are described above. If the country identification code stored in a specified area of the memory is a country other than the specified country, the PI code is 1
4. The multiplex broadcast receiver according to claim 3, wherein a country identification code of 4 bits and a broadcasting station code of 9 bits to 16 bits are used as the specific part of the codes. 5. A predetermined area of the memory corresponding to the preset key is a PI code (home PI) acquired from the frequency (home frequency) of the received broadcast wave at the time of presetting the preset key and the RDS data included in this received broadcast wave.
A first storage area for storing a code), a frequency (current frequency) of a broadcast wave received by the subsequent automatic follow-up channel selection, and a PI code (current PI code) and AF obtained from RDS data included in this broadcast wave. 4. The multiplex according to claim 3, further comprising a second storage area for storing a list, wherein the PI code and a specific part of the code are checked for the home PI code and the current PI code, respectively. Broadcast receiver.