JPH08251050A - Receiver - Google Patents

Abstract

PURPOSE: To shorten a scanning time by selecting one frequency out of a frequency list of broadcasting stations having the same contents, detecting the electric field intensity of a radio wave of the selected frequency, and outputting the sound when the reception intensity is larger than a specific quantity. CONSTITUTION: An FM reception and demodulation part 2 receives a 1st frequency in the list, and measures and outputs the electric field intensity to a control part 13 immediately. The control part 13 stores a memory 12 with the measured electric field intensity level of the 1st frequency as, for example, a value (b). In this case, a specific quantity is assumed to be 20dBμ and when b>=b' holds, control is so performed as to perform reception at the 1st frequency, thereby turning on the sound switching part 11. The detecting operation is repeated at specific intervals of time. If b<b' holds, on the other hand, a PLL part 4 is put back to the frequency right before the control, and then control for turning on the output of the switching part 11 is performed immediately and a reception state is entered. Consequently, variation in the frequency of the PLL 4 due to frequency switching is reducible and can speedily be followed up.

Description

Detailed Description of the Invention

[0001]

The present invention relates to RDS (Radio Data S
ystem) The present invention relates to a receiving device for receiving broadcast.

[0002]

2. Description of the Related Art In an RDS radio receiving apparatus, based on a broadcasting station list having the same contents obtained by demodulating an RDS signal, first, all frequencies in the list are detected and stored by detecting the intensity of reception and are obtained by RDS demodulation. The frequency is scanned while storing the station number peculiar to the broadcast station. Next, the station having the strongest electric field strength and the good reception state is selected and received. After that, when the reception intensity of the receiving station becomes equal to or lower than the predetermined intensity, the scanning operation is performed again.

[0003]

Conventionally, at the time of scanning, it is possible to select a station having the same content and the strongest electric field strength and a good reception state. However, the FM installed in a mobile body such as an automobile is selected. In the receiving device, since the electric field strength detected at the time of reception changes as the mobile device moves, the reception state may not be good. This problem can be solved by providing a means for constantly scanning the frequencies of the broadcasting station list having the same contents.

However, even in this case, as in the prior art, in the operation of detecting and storing the intensity of reception of all frequencies based on the list and storing the station number peculiar to the broadcasting station obtained by the RDS demodulation, it is usually 0. Since it takes about 0.5 to 10 seconds, there is a drawback that the sound is interrupted for a long time during operation. In addition, even if the sound is interrupted for a short time, turning the sound signal on and off when the volume is relatively high causes annoyance to the listener, causing discomfort to the listener.

An object of the present invention is to provide a mobile-device-mounted receiving device capable of selecting a broadcasting station having the best reception condition from broadcasting stations having the same contents by shortening audio interruption.

[0006]

The present invention is obtained by demodulating RDS data every predetermined time by a time counting means for counting a predetermined time and a count of the time counting means in a receiving device for receiving an RDS broadcast. A means for receiving a radio wave of the first frequency from a plurality of broadcasting stations of the same content having different frequencies and turning off the audio output, and a reception strength detecting means for the radio wave of the first frequency to detect the electric field strength and have a predetermined level or more. When it is detected that the first
Means to receive radio waves of the frequency of and turn on the audio output,
A receiving device provided with means for receiving a radio wave of the frequency received immediately before the radio wave of the first frequency when a predetermined level is not detected, and with means for repeatedly receiving the radio waves of a plurality of different broadcasting stations having the same content. Is.

According to the first aspect of the present invention, the time is counted when the electric field strength detected by the reception strength detecting means is at a predetermined level.
And a second time counting means for counting time when the predetermined level is not reached, and when the predetermined time is counted by the second time counting means, a plurality of different frequencies obtained by demodulating the RDS data are provided. Is a receiving apparatus including means for receiving a radio wave of the first frequency from the broadcast of the same content and turning off the audio output.

[0008]

Operation: One frequency is selected from the frequency list of broadcasting stations having the same contents obtained by RDS demodulation, the electric field strength of the radio wave of the selected frequency is detected, and if the reception strength is a predetermined amount or more, voice output is performed. Is output, the time for scanning the radio waves in the frequency list can be extremely shortened. Then, the frequency in the list is repeatedly scanned by the time counting means every predetermined time, so that the broadcasting station having a strong electric field strength can be received without interruption of the sound.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 is a schematic block diagram of an FM receiver showing an embodiment of the present invention. In FIG. 1, 1 is an antenna unit for receiving radio waves from a broadcasting station, 2 is an FM wave detected by an FM reception demodulation unit, and the reception frequency of the FM reception demodulation unit 2 is via a reception frequency control line 3. PLL (Phase Locked
Loop) unit 4, and the frequency is controlled by the PLL unit 4. The FM reception demodulation unit 2 outputs an intermediate frequency in which a voice signal, an RDS signal, and a constant frequency carrier are mixed to the intermediate frequency transmission line 5, and outputs an electric field intensity of a received broadcast wave to the reception intensity transmission line 6 It is a means.

The intermediate frequency transmission line 5 includes a voice demodulation section 7,
It is also connected to the RDS demodulation unit 8. Reference numeral 7 is an audio demodulation unit for extracting only the audio signal from the intermediate frequency signal from the FM reception demodulation unit 2, and 8 is an R signal for detecting only the RDS signal from the intermediate frequency signal and outputting it to the RDS data transmission line 9
The DS demodulator 8. The output of the voice demodulation unit 7 is input to the voice switching unit 11 through 10 voice transmission lines. The voice switching unit 11 further has a memory 12 such as a RAM and is connected to a control unit 13 including a microcomputer. The on / off control signal of the control unit 13 outputs the audio signal input to the audio switching unit 11 via the audio output line 14 (audio output is turned on) or not output (audio output is turned off).
This is a voice switching unit for selecting whether or not. Voice switching unit 11
Is a muting circuit composed of switch ICs and transistors.

The control unit 13 includes a list creating means for extracting a frequency list for broadcasting the same contents as the current receiving station from the RDS information demodulated by the RDS demodulating unit 8, and an FM.
PL so that the reception frequency of the reception demodulator 2 can be arbitrarily selected
Means for controlling the PLL unit 4 via the L control line 15;
The control unit has a unit for measuring a reception intensity signal output from the reception demodulation unit 2 and a control unit for turning on / off the voice output of the voice switching unit 11. Further, in the control section 13, the time counting means 13a for counting the clock signal of the microcomputer can perform the reception control at every predetermined time. Also, the time counting means 1
3a may be composed of a timer circuit or the like, and a control signal may be output to the control unit 13 at predetermined time intervals to control reception.

In the receiving state, the control unit 13 always creates, by the list creating means, the data of the broadcasting stations in which the same contents are broadcast from the RDS information as a frequency list and stores it in the memory 12. For example, frequency data of 10 stations is stored in a memory that stores information for 25 stations. The electric field strength of one frequency (f0) to be received is measured by measuring the signal of the reception strength transmission line 6 from the FM reception demodulation unit 2 and the detected electric field strength level is stored in the memory 12.

FIG. 2 is a flowchart showing the operation of the receiving apparatus of this embodiment. In FIG. 2, in this embodiment,
First, the control unit 13 sets the currently set frequency (f0).
Is recognized (S1), and when a predetermined time is counted by the time counting means 13a (S2), one is selected from the frequency list of the same content broadcasting stations. Normally, the PLL unit 4 is controlled so as to receive the first frequency (f1) in the order of the frequencies of the same content broadcast sent from the broadcasting station (S3). In S2, the reception control is normally performed at intervals of 5 seconds, but other time intervals such as 1 second and 7 seconds may be used.

In the above example, one frequency is selected in the order of the frequencies of the same content broadcast sent from the broadcasting station, but the frequencies of the same content are stored in the memory in ascending order (for example, 95.0 95.4 96.0 MHz. ...) or in ascending order (for example, 96.0 95.7 95.0 93.5 MHz ...) By the control unit 13 and arranging them in the memory 12 and sequentially receiving frequencies, compared to when randomly scanning frequencies, Since the change in the frequency of the PLL unit 4 due to the frequency switching can be reduced, the PLL unit 4 can be made to quickly follow a predetermined frequency. When all the frequencies of the same content have been scanned in the order of low frequency, the scan is performed again from the lowest frequency, but the scan may be performed from the highest frequency.

Next, it is detected whether the selected frequency (f1) is the same as the frequency set immediately before the selection (S
4). If they are the same, another frequency, for example, the second frequency (f2) is set (S5). When the predetermined frequency (f2) is set, the output of the voice switching unit 11 is controlled to be turned off (S6). If the same frequency is not set, the FM reception demodulation unit 2 receives the first frequency (f1) in the list and measures the electric field strength (S
7) Immediately, the electric field strength is output to the control unit 13 via the reception strength transmission line 6.

The control unit 13 stores the electric field intensity of the first frequency (f1) to be received in the memory 12 as the value b of the electric field intensity level measured by the reception intensity measuring means. At this time, the predetermined amount b ′ is set to 20 dBμ and b ≧
If it is b ′ (S8), control is performed so that reception is performed at the first frequency (f1), and the voice switching unit 11 is turned on (S8).
9). Then, the detection operation is repeated again every predetermined time.
However, if b <b ', the frequency (f0) immediately before controlling the PLL unit 4 is returned (S10), and then the output of the voice switching unit 11 is immediately turned on (S9) to enter the receiving state. .

Then, in S1, the current set frequency is recognized,
When the time counting means 13a again reaches a predetermined time, the PLL unit 4 is controlled so as to receive the second frequency (f2) in the frequency list of the same content broadcasting station, and the FM reception demodulation unit 2 receives the second frequency. Set (f2). In the subsequent operations, the processing from S3 to S9 is similarly repeated.

When the processing is performed up to the tenth (f9) in the frequency list of the same content broadcasting station, the frequency is set as the first (f1). At this time, if the number of broadcasting stations having the same content is n, the n-th broadcasting is repeated. A predetermined time is counted by the time counting means 13a, and it usually takes about 15 milliseconds before the voice switching unit 11 turns on the frequency output and the voice output that has been turned off. In the processing time as described above, the frequencies in the frequency list are repeatedly scanned at predetermined time intervals to set the frequency in a good reception state.
It is possible to receive a broadcasting station with a strong electric field strength without any noticeable sound interruption.

According to the above, the time counting means 13a scans the frequency list every 5 seconds, but the electric field strength sent from the reception strength transmission line 6 is stored in the memory 12.
If a plurality of times to be counted by the time counting means 13a are provided and switched according to a predetermined electric field strength level, it is possible to receive with high scanning efficiency. That is, the count time is switched on condition that the value of the predetermined time detected in S2 of FIG. 2 is detected and stored in S7.

For example, when the electric field strength is greater than 17 dBμ, the frequency list is scanned every 5 seconds as the first counting means, and the electric field strength is relatively weak at 17 dBμ.
In the following cases, the frequency list is scanned every second as the second time counting means. Further, for 20 dBμ or more, the scanning operation performed every 5 seconds may be stopped once every three times. At this time, the processes other than S2 are the same as those described above. In this way, when the electric field strength is strong, the scanning interval is widened to reduce the operation that causes the interruption of the voice, and when the electric field strength is weak, the scanning interval is narrowed, so that the electric field strength can be quickly increased. It can scan and receive the strong frequency of.

According to the present invention, since only one station is selected and received from the frequency list of broadcasting stations having the same contents, the time for scanning the frequency list can be made extremely small, and it does not cause noise. Can be received.
Further, since the other frequencies in the frequency list are sequentially received, it is possible to receive a station having a strong electric field strength.

[0022]

According to the present invention, the broadcasting stations can be switched in a short time by selecting and receiving only one station from the frequency list of broadcasting stations having the same contents. Further, since the station of the repeated frequency list is received, it is possible to provide the receiving apparatus for mounting on the moving body, which does not cause discomfort to the listener who can receive a broadcast station having a high electric field strength with a short break in sound.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a receiving device showing an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the receiving apparatus according to the embodiment of the present invention.

[Explanation of symbols]

 1 antenna section 2 FM reception demodulation section 3 reception frequency control line 4 PLL section 5 intermediate frequency transmission line 6 reception intensity transmission line 7 voice demodulation section 8 RDS demodulation section 9 RDS data transmission line 10 voice transmission section 11 voice switching section 12 memory 13 Control unit 13a Time counting means 14 Audio output line 15 PLL control line

Claims (2)

[Claims] 1. A receiving device for receiving an RDS broadcast, comprising: time counting means for counting a predetermined time; and RD for every predetermined time by counting by the time counting means.
By means for receiving radio waves of the first frequency from a plurality of broadcasting stations of the same content having different frequencies obtained by demodulating the S data and turning off the audio output, and for receiving intensity detection means for the radio waves of the first frequency. A means for receiving the electric wave of the first frequency and turning on the voice output when the electric field strength is detected to be equal to or higher than a predetermined level, and a radio wave of the first frequency when the predetermined level is not detected. A receiving apparatus comprising means for receiving radio waves of the frequency received immediately before, and means for repeatedly receiving radio waves of a plurality of different broadcasting stations having the same content. 2. A first time counting means for counting time when the electric field strength detected by the reception strength detecting means is at a predetermined level, and a second time counting means for counting time when the electric field strength is not at the predetermined level. , When the predetermined time is counted by the second time counting means, R
2. The receiving apparatus according to claim 1, further comprising means for receiving radio waves of a first frequency from a plurality of broadcasts having the same content and having different frequencies obtained by demodulating the DS data and turning off an audio output.