JPH03185934A - Receiver - Google Patents

Abstract

PURPOSE:To use only one reception block system and to reduce the cost by providing a controller or the like storing plural broadcast frequency data included in an RDS(radio data system) signal. CONSTITUTION:In the case of receiving a radio wave of an RDS system broadcast station with a reception block 100, an RDS signal is inputted to a controller 13 via an RDS signal demodulator g and plural broadcast frequency data in the AF signal is stored in a memory. Simultaneously, an S meter output SD outputted from a detector 4 is detected and when the level is smaller than a reference value, a signal MUTE is outputted to a mute circuit 6 and a voice output is interrupted. Then a broadcast frequency data FD different from that during reception at present is outputted sequentially to a PLL circuit 10 among the plural broadcast frequency data stored in advance. When a level of the output SD is larger than the reference value, the data is outputted to the circuit 10 to stop the output of the signal MUTE. Thus, one system of the reception block is enough and the cost is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a receiver, and particularly to an AF (Alternate) receiver.
RDS (R
The present invention relates to a receiver compatible with the Adio Data System) system.

[Conventional technology]

Conventionally, this type of receiver has used a circuit as shown in FIG. 3, for example.

In FIG. 3, the system from the antenna 1 to the speaker 8 and the PLL circuit section 10. The low pass filter 11° local oscillator 12 is a block of a commonly used PLL frequency synthesizer type transmitter.

If you are currently receiving RDS broadcast radio waves, the RD
The S signal demodulator 9 inputs the RDS signal RD S 1 to the controller 13B.

A 1-chip microcomputer or the like is used as the controller 13B.

RDS signal RDS from RDS signal demodulator 9;

includes an AF multiplied signal having a plurality of broadcast frequency data of the same broadcasting station and the same content, and the controller 13 extracts the AF' signal from the RDS signal RDSR and stores them in the memory.

Here, if the electric field strength of the broadcasting station currently being received becomes weak,
S meter output SDI from detector 4 indicating signal strength
becomes smaller. The controller 13B is the S of the detector 4.
When the level of the meter output SD1 is determined and becomes below a certain value, the AF multiplied signal other broadcast frequency data F'S2 of the same broadcasting station stored in the memory is outputted to the PLL circuit section 10A, and the signal is output from the antenna IA to the detector. 4A, PLL circuit section 1
The S meter output SD2 of the broadcast frequency received in the system of 0A to local oscillator 12A is compared with the S meter output SD of the broadcasting station frequency currently being received, and the S meter output SD is the larger S meter output SD2. If a broadcast frequency exists, the broadcast frequency data is output to the PLL circuit section 10.

By using the above-described method, it was possible to receive broadcasts from broadcast stations with the same content and with a strong electric field at all times while switching the frequency.

[Problem to be solved by the invention]

The above-described conventional receiver requires two systems of receiving blocks in order to operate the AF function, which has the disadvantage of high cost.

An object of the present invention is to provide a receiver that can reduce costs.

[Means to solve the problem]

The receiver of the present invention includes a PLL frequency synthesizer type communication block which inputs broadcast frequency data and receives broadcast radio waves of a broadcast frequency corresponding to the broadcast frequency data;
a mute circuit that stops outputting the audio signal from the reception block when a mute signal is input; and an RDS that includes an AP signal having a plurality of broadcast frequency data of the same broadcasting station and the same content from the reception signal of the reception block. an RDS signal demodulator for extracting a signal, storing a plurality of broadcast frequency data included in the RDS signal, and outputting and storing the mute signal when the level of the received signal of the receiving block falls below a reference value. Outputting broadcast frequency data of a broadcast frequency different from the broadcast frequency currently being received among the plurality of broadcast frequency data being received to the receiving block, and the level of the received signal of the receiving block becoming higher than the reference value. and a controller that stops outputting the mute signal to the mute circuit when the mute signal is output to the mute circuit.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

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

In this embodiment, antenna 1. High frequency amplifier 2° mixer 3
．． Detector 4. Demodulator5. PLL circuit section 10. A PLL frequency synthesizer type signal block 1 includes a low-pass filter 11 and a local oscillator 12, and receives broadcast frequency data FD and receives broadcast radio waves of a broadcast frequency corresponding to the broadcast frequency data FD.
0, a mute circuit 6 that stops outputting the audio signal from the receiving block 100 when a mute signal MUTE is input, and a plurality of broadcast frequency data of the same broadcasting station and the same content from the received signal of the receiving block 100. an RDS signal demodulator 9 that extracts an RDS signal RDS including an AF multiplied signal;
A plurality of broadcast frequency data included in the RDS signal 'RDS are stored, and a mute signal MUT is generated when the level of the received signal of the receiving block 100 falls below a reference value.
E is output, and broadcast frequency data FD of a broadcast frequency different from the broadcast frequency currently being received among the plurality of stored broadcast frequency data is output to the reception block 100, and the level of the reception signal of the reception block 100 is adjusted. The configuration includes an amplifier 7 that mutes the mute signal MUTE when the value exceeds the reference value, a display driver 142, a display device 15, and a key input unit 16.

When the reception block 100 is currently receiving radio waves from an RDS broadcasting station in the FM band, the RDS signal demodulator 9 inputs the RDS signal RDS to the controller 13 . The controller 13 is a one-chip microcomputer or the like, and processes the RDS signal RDS output from the RDS signal demodulator 9.

If the AF function is selected here, the controller 13
extracts the AF multiplied signal from the RDS signal RDS, and stores a plurality of broadcast frequency data having this AF multiplied signal in a memory.

At the same time, the controller 13 detects the S meter output SD output from the detector 4, and performs the AP operation when the level of the S meter output SD becomes smaller than the reference value.

In this AF operation, first, when the S meter output SD becomes small, a mute signal MUTE is output to the mute circuit 6 to interrupt audio output.

Next, the controller 13 preliminarily selects broadcast frequency data FD of a frequency different from the currently received broadcast frequency out of the plurality of stored broadcast frequency data.
Output to the L circuit section 10.

Since the number of broadcast frequencies usually ranges from several stations to several tens of cycles, the controller 13 sequentially outputs the broadcast frequency data of the same broadcast station to the PLL circuit section 10. Also, the level of the S meter output SD is checked for each broadcast frequency data.

The controller 13 checks the level of the S meter output SD for - different broadcast frequency data, and if there is broadcast frequency data with a level higher than the reference value, it outputs the broadcast frequency data to the PLL circuit section 10 and outputs the mute signal MUTE.
Stop outputting.

The mute signal MUTE is output when the electric field strength of the broadcasting station currently being received weakens, but since switching of the broadcasting frequency usually ends after about 50m5, the audio mute time is
Approximately 200 to 300 m5 is sufficient for the broadcasting frequency of the same station, and even if you check the reception level for all broadcast frequency data while listening to the currently receiving broadcasting station, there will be no interruptions in the audio of the currently receiving broadcasting station. can be kept to a non-disruptive level.

FIG. 2 is a block diagram of a second embodiment of the invention.

In this embodiment, in addition to the first embodiment, the output from the demodulator 5 is input to the controller 13A.
The demodulator 5 outputs actual audio data as a voltage. That is, a low voltage is output when there is no audio signal in the broadcast radio waves being received (during silence). The controller 13A determines this audio level, and when the broadcast becomes silent, it outputs a mute signal MUT as in the first embodiment.
E is output and AF operation is performed.

In this embodiment, the time during which muting is applied often overlaps with silent periods of broadcasting, and the audio currently being received is muted, further reducing the bothersomeness of audio interruptions.

Furthermore, in normal broadcasting, silence is often at intervals of several seconds, and can be performed without significantly affecting the AF operation.

-9- [Effects of the Invention] As explained above, the present invention stores a plurality of broadcast frequency data of the same broadcasting station and the same content, such as the AP multiplied signal of the RDS signal, and allows the received signal level to meet a predetermined standard. When the value drops below the value, a mute signal is output and audio output is stopped.
During this time, a broadcast of a broadcast frequency different from the broadcast frequency currently being received is received, the level of this received signal is checked, and when this level becomes larger than a reference value, the output of the mute signal is stopped. Since only one receiving block is required, there is an effect of reducing costs.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a first embodiment of the present invention, FIG. 2 is a block diagram of a second embodiment of the present invention, and FIG. 3 is a block diagram of a conventional receiver. 1...Antenna, 2...High frequency amplifier, 3...Mixer, 4...Detector,
5.5A... Demodulator, 6... Mute circuit, 7... Amplifier, 8... Speed 10
- -F, 9...RDS signal demodulator, 10...
...PLL circuit section, 11...Low-pass filter, 1
2...Local oscillator, 13, 13A, 13i+.
... Controller, 14 ... Display driver, 15 ... Display device, 16 ... Key human power section, 100, 1OOA ... Reception block.

Claims (1)

[Claims] A PLL frequency synthesizer receiving block inputs broadcast frequency data and receives broadcast radio waves of a broadcast frequency corresponding to the broadcast frequency data, and stops outputting audio signals from the receiving block when a mute signal is input. a mute circuit; an RDS signal demodulator for extracting an RDS signal including an AF signal having a plurality of broadcast frequency data of the same broadcasting station and the same content from the received signal of the reception block; and a plurality of broadcast frequencies included in the RDS signal. What is the broadcasting frequency currently being received among the plurality of stored broadcasting frequency data? and a controller that outputs broadcast frequency data of different broadcast frequencies to the reception block and stops outputting the mute signal to the mute circuit when the level of the reception signal of the reception block becomes higher than the reference value. A receiver featuring: