JPS5863241A - Synthesizer receiver containing multifunction - Google Patents

Abstract

PURPOSE:To obtain the titled receiver which can always maintain the best receiving state and is suited to a car radio, etc., by providing the best receiving state selecting function, the diversity function and the automatic sound volume control function respectively and obtaining the good output at all times in any receiving state. CONSTITUTION:The signal is received at a receiving frequency synthesizer part STY1 and fed to a stereo demodulator MPX1 via a wave detector DET1. The L and R signals delivered from the MPX1 are applied to speakers SP1 and SP2 via electronic volumes EV1 and EV2 respectively. At the same time, a searching frequency synthesizer part SYT2 having the same constitution as the ssyt1 searches the area within a broadcast band to have the successive tuning with an optional broadcast station. The outputs of the MPX1 and MPX2 are compared with each other through a comparator COP1, and the larger output is selected by the output of a control circuit CONT via a function selecting switch SW4 when these outputs have the same contents. In addition, the output level of the MPX1 is compared with the detected output levels of the ambient noise and the audio output through an automatic sound volume controller AVC. Then the volumes EV1 and EV2 are automatically controlled with the output of comparison.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a synthesizer receiver with multiple functions.

Generally, when a large number of broadcasting stations (affiliated stations) under a particular affiliate are broadcasting the same program at the same time, a receiver such as a car radio can receive signals within the coverage area of several affiliate stations. It would be extremely beneficial to be able to automatically listen to the same program continuously and with the best reception.

In addition, in an FM receiver, in order to improve fading, signals of the same frequency are received at the same time in different locations, and the one with less multipath noise is selected - t, b space.
It is also beneficial to have a diapersity function.

Furthermore, it is also beneficial to provide an automatic volume adjustment function in the AM/FM receiver to increase or decrease the receiver output, that is, the speaker output, depending on the amount of surrounding noise.

SUMMARY OF THE INVENTION In view of the above-mentioned benefits, it is an object of the present invention to provide a new synthesizer receiver having various functions such as a best reception state selection function, a diversity function, and an automatic volume adjustment function.

The invention will now be described according to illustrated embodiments.

The figure is a block circuit diagram of a synthesizer receiver with multi-functions according to the present invention, which is particularly configured as an FM stereo receiver. IF1
Stereo demodulator MPX via F1 signal detector DET1
1, and output from this stereo demodulator, the black signal and the R signal are respectively input to the electronic volume EV1. EV
2. and low frequency amplifier AMP1. AMP2. via speaker SP1. Given to SP2. The reception frequency synthesizer section 5YT1 uses a known prescaler type P.
PL with LL circuit, 1 local oscillator, 9 frequency divider, programmable divider, phase detector, and low pass filter
The oscillation frequency of the local oscillator is controlled by the data signal supplied to the programmable divider, so that any desired frequency can be received. This data signal indicates the tuning frequency corresponding to the broadcast station that the listener wishes to tune to, and the listener can select one of the tuning modes by setting it to preset tuning, automatic tuning, or manual tuning.
For example, it is given via line a from a control unit CNT constituted by a microcomputer.

In order to provide the best reception state selection function, a detection frequency synthesizer section 5YT2 having the same configuration as the reception frequency synthesizer section 5YT1 is provided. This detection frequency synthesizer section receives a search data signal supplied to its programmable divider via line b from the control section CNT in order to constantly search within the broadcast band.

An IF2 signal is output upon reception of an arbitrary broadcast station.

This IF2 signal is given to the stereo demodulator MPX2 via the detector DET2.

The L and R outputs of the stereo demodulator MPX1 are connected to position 1 of the switch SW4 and to the level adder AI.
) DI, and the output of the level adder ADD 1 is connected to the first manual power of the automatic volume controller AVC and the comparator CMP 1.
connected to the first human power source. On the other hand, the stereo demodulator MP
The L output and R output of
It is connected to the second manual power of the automatic volume controller AVC via W2. The automatic volume controller AMC is an IC circuit configured to convert the first and second human power into AC:/DC: and subtract this converted signal. The output of this automatic volume adjuster is.

Comparator CMP1 in its position 1 via switch SW3
connected to the electronic volume EV at position 3.41'
1 and EV2.

When the interlocking switches SW1-SW5 are set to position 1, the receiver is in the best reception selection function mode. It is assumed that the receiving frequency synthesizer section 5YTi is receiving station A. Every time the detection frequency synthesizer unit 5YT2 searches within the broadcast band and receives an arbitrary station, the automatic volume controller AVC controls the rail adder ADD1. ADD2
An instantaneous waveform comparison of the broadcast contents is performed via the , and when the broadcast contents match.

That is, when the detection frequency synthesizer unit 5YT2 receives a B station under a specific series, the output of this automatic volume adjuster becomes zero. This activates the comparator CMP1 via position 1 of the switch SW3, which compares the levels of the level adders ADD1 and ADD2. In this rail comparison.

ADDl) At the time of ADD2, the comparator CMP1 outputs a positive signal ξ, and the control unit CNT causes the receiving frequency synthesizer unit 5YT1 to continue receiving the A station via the line a, and at the same time causes the receiving frequency synthesizer unit 5YT1 to continue receiving the A station via the line b. Have the detection frequency synthesizer section 5YT2 start searching for a new broadcast station. On the other hand, when ADDI (ADD2), comparator CMP
I outputs a negative pulse, and the control unit CNT switches the data signal on line a from a signal indicating the tuning frequency of station A to a signal indicating the tuning frequency of station B, and then switches it to the detection frequency synthesizer unit via line b. 5YT2 starts searching for a new broadcasting station.In this way, the broadcasting station with the same broadcast content and the best reception condition is automatically selected and received.

When switches SW1-SW3 are set to position 2, the receiver is in the diversity function mode.

The outputs of the reception frequency synthesizer section 5YT1 and the detection frequency synthesizer section 5YT2 are each output from a comparator CM.
Connected to the first and second human power of P2.

If multipath interference exists, the presence or absence of multipath interference can be checked by checking whether there is a fluctuation in the IF signal level, since the FM wave is amplitude modulated.

Antenna AT1. The receiving frequency synthesizer unit 5YT1. Detection frequency synthesizer section 5YT2
Assuming that both are receiving the same broadcast content, the comparator CMP2 compares the levels of the IFI signal and IF2 signal that are output from there, and depending on the magnitude, 1, for example, is correct when the IFI signal is good. Outputs a negative pulse when the pass # and rF2m are good.

Accordingly, the control unit CNT outputs an activation signal to switch the switch sw4 to position 1 or 2. Therefore.

In this mode, the receiver can always select the receiving system with less multipath interference.

When the switches SW1 to SW3 are set to position 3, the receiver has an automatic volume adjustment function added to the single reception mode of the reception frequency synthesizer section 5YT1. The microphone MIC is connected via position 6 of the switch sw2 to the second manual of the automatic volume regulator AVC, the output of which is connected via position 6 of the switch SW3 to the electronic volume EV1. Connected to EV2. Microphone MIC is connected to speaker SP1. Detect SP2 output and ambient noise. As mentioned above, the AC/DO converter provided in connection with the second manual power in the automatic volume controller AVC is provided with an amplifier at its front stage, and the gain of this amplifier is as follows.
Speaker SP1. The output level of SF3 and the signal rail of the first human power are adjusted in advance so that they are the same. Therefore, 1. When there is no ambient noise, both input levels of the subtractor in the automatic volume controller AVC are equal and the output is zero, but when there is ambient noise, a signal proportional to the noise level is generated. is output from the subtracter, and in response to this output level, the electronic volume EV1. Adjust EV2. As a result, the speaker SF'1. S
The output of F3 can be increased automatically.

Finally, when switches SW1 to SW3 are set to position 4, the receiver receives frequency synthesizer section 5YT1.
, and therefore functions as a normal FM receiver.

Although the present invention has been described as an FM stereo receiver in the above embodiment, it goes without saying that it can be applied as an AM receiver and receiver by excluding the dimerity function specific to FM reception waves.

Furthermore, various combinations of functions are possible by appropriately changing the connections of the function selection switches SW1 to sw3.

The present invention, such as the one shown above, can always obtain good broadcasting output under all reception conditions, and is particularly suitable for car radios.

[Brief explanation of drawings]

The figure is a block circuit diagram of an embodiment in which the present invention is applied to an FM stereo receiver. (Explanation of symbols) ATl, AT2: Antenna. 5YT1: Receiving frequency synthesizer section. 5YT2: Detection frequency synthesizer section. CNT: Control unit, DETl, DKT2: Detector. MPXl, MPX2 Nistereo demodulator. ADDl, ADD2 Two-level adder. CMPl, CMP2: Comparator, AVC: Automatic volume fl, rectifier. SW1 to SW3: Function selection switches. SW4: Receiving system selector switch. EVl, EV2: Electronic volume. AMPl, AMP2: Low frequency amplifier. SPl, SF3: Speaker. MIC: Microphone.

Claims (2)

[Claims] (1) A first receiving system equipped with a reception frequency synthesizer section that tunes to the desired broadcasting station, and a detection frequency synthesizer section that searches within the broadcast band and tunes 11th to any broadcast station. The detection output of the first reception system and the detection output of the second reception system are compared, and when the detection outputs of both are the same broadcast content, K a best reception state selection function that selects the one with a higher detection output level as the audio output; and a detection output level of the first receiving system and a detection level of ambient noise and audio output are compared and depending on the level of the ambient noise. and an automatic volume adjustment function for adjusting the audio output of the first receiving system. (2) A first FM stereo reception system equipped with an FM reception frequency synthesizer section that tunes to the desired broadcast station, and an FM detection frequency that searches within the broadcast band and sequentially tunes to any broadcast station. a second FM stereo reception system including a synthesizer section, and an interface between the FM reception frequency synthesizer section and the FM detection frequency synthesizer section;
' A diversity function that compares the F-fold signal output level and selects the one with less multipath interference among the first or second FM stereo reception system, and the detection output of the first FM stereo reception system and the A best reception state selection function that compares the detection output of the second FM stereo reception system and selects the one with the higher detection output level as the audio output when both detection outputs are the same broadcast content. , automatic comparing the detection output level of the first FM stereo reception system with detection levels of ambient noise and audio output, and adjusting the audio output of the first FM stereo reception system according to the level of the ambient noise; A synthesizer receiver characterized by having a volume adjustment function.