JP2509054B2 - Radio receiver - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio receiver suitable for receiving, for example, a frequency modulation (abbreviated as FM) radio broadcast called RDS (Radio Data System). The present invention relates to a radio receiver suitable for being used by being mounted on an automobile whose state changes.

[0002]

2. Description of the Related Art Such RDS broadcasting is carried out, for example, in Europe, and the high frequency signal of this radio broadcasting includes an audio signal and a data signal representing information on the radio broadcasting, and the data signals are the same. In the case of a radio broadcast that is similar or similar, the broadcast content of the audio signal is the same or similar. In a typical prior art, when a car enters a tunnel and the reception electric field strength of radio broadcasting becomes low, the radio receiver installed in the car stores in memory the reception frequency immediately before entering the tunnel. After being stored and the tunnel is extracted, the reception frequency is received again at the reception frequency stored in the memory. If the received electric field strength of the received frequency is less than a predetermined discrimination level, the radio receiver performs a full-round scan over the entire receivable frequency range,
To receive a radio broadcast having a strong electric field strength in which the data signals are matched during the scanning, and if a radio broadcast in which the data signals are matched is not received, perform a scan once again, Find a radio broadcast with a similar data signal.

[0003]

The scanning of such a radio receiver requires about 2 minutes to complete one round.
If no radio broadcast with a matching data signal is found by the time the first scan completes, a second scan is performed to find a radio broadcast with a similar data signal. For example, a radio broadcast is received. It takes about 5 minutes to do so, which is a long interruption time for listeners of radio broadcasting.

An object of the present invention is that when an automobile travels in a tunnel while receiving an RDS broadcast or the like in a radio receiver, the electric field strength of the received electric field becomes small and reception becomes impossible, but after the automobile exits the tunnel, It is an object of the present invention to provide a radio receiver capable of selecting a radio broadcast that is the same as or close to a radio broadcast immediately before the reception electric field strength becomes small in a short time.

[0005]

According to the present invention, there is provided a receiving means for receiving a high frequency signal including a voice signal and a data signal representing information on radio broadcasting with a variable reception frequency, and a voice signal in response to an output of the receiving means. Soundizing means for sounding
An identifying means for identifying the data signal in response to the output of the receiving means; a discriminating means for discriminating the received electric field strength at a predetermined discriminating level in response to the output of the receiving means; and an output of each of the receiving means and the discriminating means. A first memory for storing the data signal of the radio broadcast being received in response, and holding the stored contents at that time when the received electric field strength falls below the discrimination level; and a second memory. Responsive to the output of the discriminating means, when the received electric field strength is less than the discriminating level, the receiving means scans the receiving frequency for one round, and during the scanning, the receiving frequency of the radio broadcast and the data signal are included. One or more combinations are stored in the second memory, and after scanning, the degree of matching between the data signal stored in the second memory and the data signal stored in the first memory is determined. There select radio broadcast, a radio receiver, characterized in that it comprises a control means for tuning the receiving means so that the reception frequency are then stored in the second memory of the selected radio broadcast.

Further, in the present invention, the second memory further includes the received electric field strength of the radio broadcast for each combination, and the control means, when there are a plurality of radio broadcasts having the same degree of coincidence of the data signals, A radio receiver characterized by selecting a radio broadcast having a high received electric field strength.

[0007]

According to the present invention, the radio receiver responds to the output of the receiving means and the receiving means for receiving the high frequency signal including the data signal and the audio signal representing the information about the radio broadcasting with the variable receiving frequency. A sounding means for acoustically converting a voice signal, an identifying means for identifying a data signal in response to the output of the receiving means, and a discriminating means for discriminating the level of the received electric field strength at a predetermined discrimination level in response to the output of the receiving means. And the first
It is configured to include a memory, a second memory, and control means. The first memory stores the data signal of the radio broadcast being received in response to each output of the receiving means and the discriminating means, and when the received electric field strength is below the discrimination level, holds the stored contents at that time. To do. When the received electric field strength becomes lower than the discrimination level, the second memory is
While the receiving means scans the received frequency to make a round, one or a plurality of combinations including the received frequency of the radio broadcast and the data signal are stored. After the scanning, the control means selects a radio broadcast having a high degree of coincidence between the data signal stored in the second memory and the data signal stored in the first memory, and the selected radio broadcast is selected. Second
The receiving means is tuned to the receiving frequency stored in the memory. Therefore, when the received electric field strength of the radio broadcast being received is below the discrimination level, it is possible to receive the radio broadcast having a high degree of coincidence of the broadcast contents.

According to the invention of claim 1, the second aspect
The memory further includes the received electric field strength of the radio broadcast for each combination, and the control means selects the radio broadcast having a large received electric field strength when there are a plurality of radio broadcasts having the same degree of matching of the data signals. Therefore, even if the received electric field strength of the radio broadcast being received falls below the discrimination level,
It is possible to receive a radio broadcast with a high reception level and a high degree of agreement with the broadcast content being received.

[0009]

FIG. 1 is a block diagram of an embodiment of the present invention. The radio receiver 1 is used by being installed in a car,
Receive RDS frequency modulated radio broadcast. The RDS broadcast is an FM (frequency modulation) high frequency signal including a voice signal and a data signal, and is broadcast from each broadcasting station.

FIG. 2 is a diagram showing the structure of the data signal 2. The data signal 2 includes four main codes, a PI code 33, a PTY code 30, an AF code 31,
And a PS code 32. The PI code 33 includes a total of four digits D1 to D4, and the first digit D1 represents the nationality of the radio broadcasting station. The second digit D2 represents the reception service area.
The third digit D3 and the fourth digit D4 are a master station, that is, a key station, or a slave station that mainly broadcasts a signal from the master station,
Alternatively, it indicates whether it is a so-called local station that broadcasts only regional programs. Thus the third and fourth
The digits D3 and D4 indicate whether or not they are groups of radio broadcasting stations that form a common network.

First to fourth digits D1 to D4 of the PI code 33
The radio broadcasts in which all of the above are the same have the same broadcast content of the audio signal, and the first to third digits D1 to
Although the contents of the audio signals of the radio broadcasts in which D3 is the same and the fourth digit D4 is different are almost the same, a slightly different program is included.

The PTY code 30 is a code representing the type of program such as news, sports, music and traffic information. The AF code 31 represents the frequency of a so-called net station that broadcasts the same broadcast content as that broadcast by that broadcast station. The PS code 32 is a code that represents a broadcasting station name by using a so-called ASCII code.

Referring again to FIG. 1, a high frequency signal including a voice signal and a data signal 2 from a radio broadcasting station is received by an antenna 3 of a radio receiver 1, amplified by a high frequency amplifier circuit 4, and mixed by a mixing circuit. 5, received by the phase lock loop frequency synthesizer 6 and the intermediate frequency amplifier circuit 7 in the superheterodyne system, demodulated by the demodulation circuit 8, the audio signal is amplified by the low frequency amplifier circuit 10 from the line 9, and the sound is output by the speaker 11. Be converted. The received electric field strength of the radio broadcast that is tuned and received is received from the intermediate frequency amplifier circuit 7 via the line 12 and received electric field strength detection circuit 13 is received.
The received electric field strength is converted into a digital value, and is supplied from the line 14 to a processing circuit 15 realized by a microcomputer or the like. The signal from the demodulation circuit 8 is given to the RDS decoder 17 from the line 16, and the signal representing the data signal 2 shown in FIG.
It is given to the processing circuit 15 from the line 18.

The phase lock loop frequency synthesizer 6 includes an oscillator circuit 19 for generating a signal having a predetermined constant reference frequency, and a frequency divider circuit 20 having a variable frequency division ratio.
And a phase comparison circuit 21 that compares the phases of the outputs of the oscillation circuit 19 and the frequency divider circuit 20 and outputs a voltage that corresponds to the phase difference and makes the phase difference zero.
The low-pass filter 22 to which the output of the phase comparison circuit 21 is given, and the output of the low-pass filter 22 are given to perform an oscillating operation at a frequency corresponding to the voltage, and the oscillation frequency changes so that the phase difference becomes zero. The output of the voltage controlled oscillator 23 is supplied to the frequency divider circuit 20. The output of the low-pass filter 22 is given to the high-frequency amplifier circuit 4, and the output of the voltage control type oscillation circuit 23 is given to the mixing circuit 5 and used for tuning. Processing circuit 15
Is a signal for setting the frequency division ratio of the frequency dividing circuit 20 on the line 24.
To the frequency dividing circuit 20 via. The processing circuit 15 sets the frequency division ratio of the frequency dividing circuit 20 included in the synthesizer 6 so that the frequency is the reception frequency of the radio broadcast input and scanned by the key input means 25, and the desired radio broadcast is received and listened to. be able to. The PI code 33 of the radio broadcast currently being received is stored in the store area 26 of the first memory M1 provided in the processing circuit 15. The reception area of the radio broadcast currently being received is stored in the store area 27 of the first memory M1. The data stored in the store area 27 may be a frequency division ratio or the like corresponding to the reception frequency instead of the reception frequency.

FIG. 3 is a flow chart for explaining the operation of the processing circuit 15. In step n1, the received electric field strength detection circuit 13 of the currently received radio broadcast
The received electric field strength detected by is read and stored in the store area 28 of the first memory M1. In step n2, it is determined whether the received electric field strength detected by the received electric field strength detection circuit 13 has reached a predetermined discrimination level. If the received electric field strength has reached a predetermined discrimination level, step n3 Then, the reception state is continued. When the received electric field strength detected by the received electric field strength detection circuit 13 becomes less than the discrimination level due to traveling of the automobile in the tunnel or the like, step n4
Moving to the tunnel, that is, scanning of the reception frequency for finding a radio broadcast that is the same as or close to the broadcast content of the audio signal of the radio broadcast that was received immediately before the received electric field strength fell below the discrimination level. In step n4, such scanning of the reception frequency of the radio broadcast can be called, so to speak, PI search. The processing circuit 15 is provided with a memory M2 used for performing a PI search operation. The second memory M2 includes a search memory M2a, a 4-digit matching memory M2b, and a 3-digit matching memory M2c. Each memory M2a, M2
b and M2c are store areas M2a for storing PI codes
1, M2b1, M2c1, store areas M2a2, M2b2, M2c2 for storing received frequencies, and store areas M2a3, M2b3, M2c for storing received electric field strengths.
3

FIG. 4 is a flow chart showing the PI search operation of step n4 of FIG. As described above in connection with step n2 of FIG. 3, when the received electric field strength of the currently received radio broadcast becomes less than the discrimination level, the processing circuit 15 causes the frequency dividing circuit 20 via the line 24. To the frequency that can be received by the high-frequency amplifier circuit 4 and the mixing circuit 5, for example, 87.
The sequential scanning of the reception frequency is performed over the entire range of 5 to 108 MHz until it makes one cycle. In step s1, it is determined whether or not the one-round scanning of this frequency has been completed. If it has been completed, the process proceeds to step s12. Step s1
In, if the one-pass scanning of the reception frequency is not completed, the process proceeds to step s2.

In step s2, the frequency dividing ratio for the frequency dividing circuit 20, that is, the N value, of the high frequency signal to be received in the radio broadcast having the received electric field strength equal to or higher than the discrimination level is output to output the frequency dividing circuit 20. Give to. Further, the reception frequency set in this way is stored in the store area M2a2 for storing the reception frequency of the search memory M2a. In step s3, the radio broadcast RDS decoder 1 having the reception frequency of the frequency division ratio N set in step s2.
PI code 33 identified in 7 is detected and read
The code 33 is stored in the store area M2a1. The reception field strength detected by the reception field strength detection circuit 13 is stored in the store area M2a3 of the search memory M2a for storing the reception field strength.

In step s4, four digits D1 to D
The PI code 33 stored in the store area 26 of the first memory M1 composed of 4 and the PI code 33 stored in the store area M2a1 of the search memory M2a are compared by comparing each digit D1 to D4. And 4 digits D1 to D4
It is determined in step s5 whether or not all match. The four digits D1 to D4 of the PI code 33 stored in the store area 26 in the first memory M1 and the PI stored in the store area M2a1 in the search memory M2a.
When it is determined that the four digits D1 to D4 of the code 33 are all the same, the process proceeds from step s5 to step s6. If there is a non-matching digit among the four digits D1 to D4 of the PI code 33, the step is performed. Transfer to s8.

In the next step s6, the search memory M
2a in the store area M2a3 and the store area M2b in the 4-digit matching memory M2b
3 is compared with the received electric field strength stored in the store area M2a3 of the search memory M2a, and the received electric field strength stored in the store area M2b3 of the four-digit matching memory M2b is compared with the received electric field strength stored in the store area M2a3 of the search memory M2a. If it is larger than the value, the process proceeds to step s7. 4-digit matching memory M
If the received electric field strength is less than or equal to the received electric field strength stored in the storage area M2b3 of 2b, the process proceeds to step s11. At step s7, the store area M of the search memory M2a
2a1, store area M2a2, and store area M2a3 are stored in each store area M of the 4-digit matching memory M2b.
2b1 to M2b3 are respectively transferred and stored. Thus, in the 4-digit matching memory M2b, the PI code 33 is stored in the first memory M during the PI search during the PI search.
PI code 33 stored in the store area 26 of No. 1
Among the radio broadcasts in which all of the four digits D1 to D4 match, the data regarding the radio broadcast of the radio broadcast having a large received electric field intensity, that is, the PI code 33, the frequency, and the received electric field intensity are stored.

Next, the process proceeds to step s11, and the processing circuit 1
Reference numeral 5 gives a frequency division ratio, that is, a signal representing an N value to the frequency division circuit 20 through the line 24, sequentially changes the reception frequency, and then sets the reception frequency at which PI check is to be performed, Return to step s1.

In step s5, the 4-digit D1 of the PI code 33 stored in the store area 26 of the first memory M1.
To D4 and the store area M2a1 of the search memory M2a
When the four-digit D1 to D4 of the PI code 33 stored in 1 do not match even one digit, the process proceeds to step s8, and the PI code 33 stored in the store area 26 of the first memory M1 and the search memory are searched. Each 4 of the PI codes 33 stored in the store area M2a1 of M2a
It is determined whether three digits of the digits D1 to D4, that is, D1 to D3 match. If the three digits D1 to D3 of the PI code 33 match, the process proceeds to step s9. P
If the three digits D1 to D3 of the I code 33 do not match, the process proceeds to step s11.

In step s9, the 3-digit matching memory M2
The received electric field strength stored in the store area M2c3 of the search memory M2a is compared with the received electric field strength stored in the store area M2a3 of the search memory M2a. The electric field strength is the store area M2 of the memory M2c for matching three digits.
When the received electric field strength is larger than the received electric field strength stored in c3, the process proceeds to step s10, and the received electric field strength stored in the store area M2a3 of the search memory M2a is stored in the store area M2c3 of the three-digit matching memory M2c. If the received electric field strength is less than or equal to
Go to 11.

At step s10, the search memory M2 is used.
a, the store contents of the store areas M2a1 to M2a3 of a are respectively stored in the store area M2c1 of the memory M2c for three-digit matching.
~ Transfer to M2c3 and store. Thus
In the 3-digit matching memory M2c, during the PI search,
3 digits D1 to D3 of 4 digits D1 to D4 of PI code 33
Of the radio broadcasts having a high received electric field strength among the radio broadcasts having the same value, that is, PI code 3
3, the values of the reception frequency and the reception electric field strength are stored. In step s11, the frequency division ratio (N value) is increased, the reception frequency to be PI checked next is set, and the process returns to step s1.

When it is determined in step s1 that the one-round scanning of the reception frequency is completed, the process proceeds to step s12. At step s12, the four digits D1 to D of the PI code 33 stored in the storage area 26 of the first memory M1 are stored.
It is determined whether or not a radio broadcast in which all 4 are matched is receivable, and if receivable, the process proceeds to step s13, and if not receivable, that is, data is stored in each store area M2b1 to M2b3 of the 4-digit matching memory M2b. If not, the process proceeds to step s14. In step s13, the processing circuit 15
Outputs a frequency division ratio for sweeping the reception frequency stored in the store area M2b2 of the 4-digit matching memory M2b, receives a predetermined radio broadcast, and ends the PI search.

In step s14, it is determined whether or not the radio broadcast in which the three digits D1 to D3 of the four digits D1 to D4 of the PI code 33 stored in the store area 26 of the first memory M1 can be received. If reception is possible, the process proceeds to step s15, and if reception is not possible, that is, 3
Each store area M2c1 to M2c of the digit matching memory M2c
If there is no data in 3, the process goes to step s16.

At step s15, the radio receiver 1
The reception frequency stored in the storage area M2c2 of the 3-digit matching memory M2c is swept and received, and the PI search ends.

In step s16, the processing circuit 15 initializes the frequency division ratio and supplies it to the frequency division circuit 20 in order to perform scanning once again. Returning to step s2 again, the repetitive scanning of the reception frequency is performed again for one cycle over the entire receivable frequency, for example, 87.5 to 108 MHz.

As described above, when the processing shown in the flowchart of FIG. 4 is completed, the 4-digit matching memory M2
In each of the store areas M2b1 to M2b3 of b, the four digits D1 to D4 of the PI code 33 and the four digits of the PI code 33 stored in the store area 26 of the first memory M1 are the same. Data related to radio broadcasting where the received electric field strength is high, that is, PI code 3
3, the frequency and the value of the received electric field strength are stored, and the four digits of the PI code 33 stored in the store area 26 of the first memory M1 are stored in the respective store areas M2c1 to M2c3 of the three-digit matching memory M2c. Of the radio broadcasts in which the three digits D1 to D3 of D1 to D4 match, the data relating to the radio broadcast having the high received electric field strength, that is, P
The I code 33, frequency, and received electric field strength are stored. Therefore, when the PI search is completed, the second memory M2 stores data related to a radio broadcast having a high received electric field intensity with the same or similar broadcast content as the radio broadcast listened to immediately before the reception becomes impossible. Therefore, it is possible to receive a radio broadcast having the same or similar broadcast content in a good reception state in a short time after the reception becomes impossible.

FIG. 5 shows the PI of the radio receiver 1 of this embodiment.
It is a graph which shows an example of a search. FIG. 6 is a diagram showing the types of bar graphs shown in FIG. The vertical axis of the graph shows the received electric field strength of the received radio broadcast, the horizontal axis shows the received frequency, and the reference received electric field strength L0 is shown by a two-dot chain line. In this graph, when a PI search is performed for a frequency receivable by the radio receiver 1, for example, 87.5 to 108 MHz, the reception indicated by the height of the bar graph in each frequency band indicated by the width of each bar graph. It is assumed that the radio broadcast of each station having the electric field strength is received. The received electric field strength of the received radio broadcast is below the discrimination level, and the values of the PI code 33, the reception frequency, and the received electric field strength of the radio broadcast being received before the PI search is started are stored in the first memory. Stored in M1. The first
A bar graph showing a radio broadcast having the same PI code 33 in all four digits as the PI code 33 stored in the memory M1 is represented by hatching as shown in FIG. 6 (1).
4 of the PI code 33 stored in the first memory M1
Of the digits D1 to D4, the bar graph showing the received radio waves having the same PI code 33 in the three digits D1 to D3 is shaded as shown in FIG. 6 (2). Also, among the received radio broadcasts, the received electric field strength is below the discrimination level and radio checks have not been PI checked, or the received electric field strength has reached the discrimination level.
A radio broadcast in which the code 33 matches 2 digits or less is shown in FIG.
This is represented by the bar graph shown in (3).

Further, Table 1 shows broadcast data stored in the 4-digit matching memory M2b during one cycle of the search. Similarly, Table 2 shows broadcast data stored in the 3-digit matching memory M2c.

[0031]

[Table 1]

[0032]

[Table 2]

When the currently received radio broadcast is blocked by a tunnel or the like and the received electric field strength falls below the discrimination level, the processing circuit 15 starts the PI search as shown in FIGS. When the PI search is started and the radio broadcast is received, the processing circuit 15 first reads the received electric field intensity of the radio broadcast and reaches the received electric field intensity (discrimination level), for example, L0, which is the reference electric field intensity of the radio broadcast. The PI check is performed on those that are present, and the PI check is not performed on radio broadcasts that have not reached the reference value L0. Since the received electric field strength of the first received radio broadcast has not reached the discrimination level L0, the process proceeds to the next search. In the next received radio broadcast P, the received electric field strength L1 has reached the discrimination level L0, so a PI check is performed. As a result of the PI check, the PI stored in the first memory M1
Since the 4-digit D1 to D4 of the code 33 and the 4-digit PI code 33 of the searched radio broadcast match, the respective values of the PI code 33, the reception frequency f1, and the reception electric field strength L1 of the searched radio broadcast are set. 4-digit matching memory M
The data is stored in the respective storage areas 2b and the next search is started. The radio broadcast Q received next has, for example, a received electric field strength of L4 and has reached the reference value L0, and the PI check is performed. As a result, the four digits D1 to D of the PI code 33
It is assumed that the radio broadcast has the same three digits D1 to D3 out of four. The respective values of the PI code 33, the reception frequency f2, and the reception electric field strength L4 of the radio broadcast Q are stored corresponding to the respective storage areas of the 3-digit matching memory M2c. For the next radio broadcast received, the received electric field strength has reached the reference value, so a PI check is performed, but the number of digits of the matching PI code 33 is less than 3 digits.
The broadcast data of the radio broadcast is not stored and the next search is started. It is assumed that the next received radio broadcast R has the received electric field intensity L2 reaching the reference value L0, and as a result of the PI check, it is determined that the radio broadcast has four digits. Of the broadcast data already stored in each store area of the 4-digit matching memory, the received electric field strength L1 of the radio broadcast P stored in the store area M2b3 and the store once in the store area M2a3 of the search memory M2a. The values of the received electric field strength L2 of the radio broadcast R are compared, and the received electric field strength L2 of the radio broadcast R is larger than the received electric field strength L1 of the radio broadcast P.
4-digit matching memory M2 that stores the broadcast data of
Each value stored in b is rewritten with the value of the broadcast data of the radio broadcast R. Similarly, when the PI search is sequentially performed and the PI search is performed once, the broadcast data of the radio broadcast R is stored in the 4-digit matching memory M2b and the radio broadcast U of the 3-digit matching memory M2c. Broadcast data is written respectively. In this way, the data is written in the four-digit matching memory M2b and the three-digit matching memory M2c, respectively, but the reception electric field strength of the radio broadcast U in which the PI code 33 matches three digits is large. , The PI code 33 is actually 4
It is a radio broadcast R that also matches the digits. Therefore, PI
When both the 4-digit coincidence broadcast and the 3-digit coincidence broadcast of the code 33 can be received, the 4-digit coincidence broadcast is selected and received regardless of the magnitude of the received electric field strength. Further, when the 4-digit matching broadcast cannot be received at all, that is, in any 4-digit matching broadcast, the received electric field strength is the reference value L0.
If it does not reach, the radio broadcast in which the PI code 33 matches three digits is received. Also, the PI code 33 is the first
When neither the PI code 33 stored in the storage area 26 of the memory M1, the radio broadcast in which the PI code 33 matches four digits, nor the broadcast in which the PI code 33 matches three digits can be received. Again, the PI search is performed once over the entire receivable frequency range.

[0034]

As described above, according to the present invention, the radio receiver stores the data signal of the radio broadcast being received in the first memory. When the reception electric field strength of the radio broadcast being received becomes less than a predetermined discrimination level, the receiving means scans the reception frequency to make one round, and during the scanning,
Each of the one or more combinations including the radio broadcast frequency and the data signal is stored in the second memory, and after scanning,
A radio broadcast having a high degree of agreement between the data signal stored in the second memory and the data signal stored in the first memory is selected and received. Thereby, when the received electric field strength of the radio broadcast being received becomes lower than the discrimination level, it is possible to select and receive the radio broadcast having a high degree of coincidence with the received radio broadcast. Further, according to the present invention, as described above, since the radio broadcast having a high degree of coincidence with the data signal being received is selected, it is not necessary to select a station having higher reception sensitivity, and the arithmetic processing is performed. Can be simplified, which achieves the excellent effect that the search time can be shortened.

According to the second aspect of the present invention, the radio receiver stores the received electric field strength of radio broadcasting in the second memory by including it in each combination of data signals, and stores the degree of coincidence of the data signals. When there are multiple radio broadcasts with the same radio field, the one with the higher received field strength is selected.Therefore, when the received field strength of the radio broadcast being received falls below the discrimination level, It is possible to receive a radio broadcast having a high degree of coincidence with the broadcast and a high received electric field strength.

[Brief description of drawings]

FIG. 1 is a block diagram of one embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a data signal.

FIG. 3 is a flowchart for explaining the operation of the processing circuit 15.

FIG. 4 is a flowchart showing an operation of PI search in step n4 shown in FIG.

FIG. 5 is a graph showing an example of a PI search of the radio receiver 1 of this embodiment.

FIG. 6 is a diagram showing the types of bar graphs shown in FIG.

[Explanation of symbols]

 1 Radio receiver 3 Antenna 4 High frequency amplification circuit 5 Mixing circuit 6 Phase lock loop frequency synthesizer 7 Intermediate frequency amplification circuit 8 Demodulation circuit 10 Low frequency amplification circuit 11 Speaker 13 Received electric field intensity detection circuit 15 Processing circuit M1 First memory M2 Second memory

Claims (2)

(57) [Claims] 1. Receiving means for receiving a high frequency signal including a voice signal and a data signal representing information about radio broadcasting with a variable reception frequency, and an acousticizing means for acoustically converting the voice signal in response to the output of the receiving means. Identifying means for identifying the data signal in response to the output of the receiving means, discriminating means for discriminating the level of the received electric field strength in response to the output of the receiving means at a predetermined discrimination level, and outputs of the receiving means and the discriminating means In response to the above, there is provided a first memory for storing the data signal of the radio broadcast being received, and a second memory for holding the stored contents at that time when the received electric field strength falls below the discrimination level. Then, in response to the output of the discriminating means, when the received electric field strength is less than the discriminating level, the receiving means scans the reception frequency for one cycle, and during the scanning, the reception of the radio broadcast is performed. Each of one or a plurality of combinations including a wave number and a data signal is stored in the second memory, and after scanning, the data signal stored in the second memory matches the data signal stored in the first memory. And a control means for tuning the reception means so that the reception frequency stored in the second memory of the selected radio broadcast becomes the reception frequency. 2. The second memory further includes a reception electric field strength of the radio broadcast for each combination, and the control means, when there are a plurality of radio broadcasts having the same degree of coincidence of the data signals, the reception electric field strength. The radio receiver according to claim 1, wherein a radio broadcast having a larger value is selected.