JPH0575552A - On-vehicle receiver - Google Patents

Abstract

PURPOSE:To prevent the disturbance of the high frequency noises by outputting a control, signal to the high frequency noise generating source in response to the level range of the input radio waves. CONSTITUTION:A comparator 6 compares the reference voltage with a signal 4 or 5 which is proportional to the input radio wave level. The result of this comparison is given to the high frequency noise generating source via a control voltage output terminal 7. The operation of the noise generating source is turned off when the input radio wave level is lower than the prescribed one. Thus the disturbance of noises can be prevented to a receiver R.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle-mounted radio receiver and the like, and more particularly to a vehicle-mounted receiver having a function of outputting a signal according to an input radio wave level range to the outside of the receiver.

[0002]

2. Description of the Related Art Conventionally, there is no vehicle-mounted receiver having a function of outputting a signal according to the input radio wave level range of the receiver to the outside of the receiver.

[0003]

Since the conventional on-vehicle receiver is as described above, when the input radio wave level of the reception frequency is low, an air purifier or the like (in the vehicle There was a problem such as interference from high frequency noise generated from the source of high frequency noise that does not affect safety performance.

The present invention has been made to solve the above problems, and outputs a control signal according to the level range of an input radio wave to the outside, and uses this control signal as a source of high frequency noise. The purpose is to obtain an in-vehicle receiver that can eliminate the influence of noise by utilizing it.

[0005]

The on-vehicle receiver according to the present invention compares the magnitude of a signal corresponding to the level of an input radio wave with a reference voltage to determine a control signal for a source of high frequency noise. The comparison means for outputting to the outside is provided.

[0006]

The on-vehicle receiver according to the present invention outputs the control signal corresponding to the level range of the input radio wave from the comparing means so that the source of the high frequency noise is not disturbed by the source of the high frequency noise. Control the behavior of.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 is an antenna, and 2 is an RF (high frequency amplification) circuit / IF (intermediate frequency amplification) circuit / DET (detector) circuit, etc. for receiving, tuning, amplifying and detecting FM radio waves from the antenna 1. The FM signal processing circuit 3 includes an RF circuit / IF circuit / DET circuit, etc. for receiving, tuning, amplifying and detecting AM radio waves from the antenna 1
It is an M signal processing circuit.

Reference numeral 4 denotes an F output from the FM signal processing circuit 2.
FM input radio wave level signal proportional to M input radio wave level,
Reference numeral 5 is an AM input radio wave level signal output from the AM signal processing circuit 3 and proportional to the AM input radio wave level. Reference numeral 6 is a comparator circuit composed of a switch section of the input section and a comparator, and the FM input radio wave level signal 4 or the AM input radio wave level signal which is selected by a reference voltage and a switching signal from an AM / FM changeover switch 8 described later. 5
When the reference voltage is higher, a low level signal is output to the control voltage output terminal 7 and when the reference voltage is lower, a high level signal is output to the control voltage output terminal 7.

Reference numeral 8 is an FM signal from the FM signal processing circuit 2,
An AM / FM switch for selecting one of the AM signals from the AM signal processing circuit 3, and 9 for a sound quality / volume adjusting circuit for adjusting the sound quality / volume of the selected signal.
Is a power amplifier in the subsequent stage, and 11 is a speaker that converts the output signal of the power amplifier 10 into sound. The vehicle-mounted receiver R is composed of the above-mentioned 2 to 10 constituent elements.

The on-vehicle receiver R configured as described above
Is connected to the source of high frequency noise mounted on the same vehicle as this using the control voltage output terminal 7. The source of the high frequency noise is configured to be in an operating state or a non-operating state according to the high level and the low level of the output signal of the comparator circuit 6.

Next, the operation of this embodiment will be described with reference to FIG. The FM radio wave of the desired reception frequency and the AM radio wave of the desired reception frequency received by the antenna 1 are processed (tuned / amplified / detected) by the FM signal processing circuit 2 and the AM signal processing circuit 3, respectively, and the FM signal and the AM signal are received. Become AM / F
It is input to the M changeover switch 8 and one of them is selected. The selected received signal has its sound quality and sound volume adjusted by the sound quality / volume adjusting circuit 9, is further amplified by the power amplifier 10, is converted into sound such as music by the speaker 11, and is output.

On the other hand, the comparator circuit 6 receives the FM input radio wave level signal 4 proportional to the level of the FM input radio wave of the desired frequency received from the FM signal processing circuit 2 and the level of the AM input radio wave of the desired frequency received from the AM signal processing circuit. The AM input radio wave level signal 5 proportional to is input from the AM / FM changeover switch 8. Then, the comparator circuit 6 compares the FM input radio wave level signal 4 or the AM input radio wave level signal 5 corresponding to the signal selected by the AM / FM switch 8 with the reference voltage.

As a result, the comparator circuit 6 outputs a low level signal when the input radio wave level is lower than the predetermined level and the reference voltage is higher, and the low level signal is higher when the input radio wave level is higher than the predetermined level and the reference voltage is lower. In this case, a high level signal is output to the control voltage output terminal 7.

The high-frequency noise source does not operate when the signal received from the control voltage output terminal 7 is low level, but operates when the signal is high level. That is,
When the level of the input radio wave of the desired reception frequency is weaker than a predetermined level, the in-vehicle receiver R can be set by outputting a low level signal from the comparator circuit 6 to deactivate the high frequency noise source. The influence of noise from the source of this high frequency noise is prevented.

Although the reference voltage is connected to the inverting input terminal of the comparator circuit 6 in the above embodiment, the reference voltage is connected to the non-inverting input terminal in reverse, and when the comparator circuit outputs a high level, the source of high frequency noise is generated. It is also possible to turn off the operation of No. 1 and turn on the operation when low level is output.

FIG. 2 shows the structure of an on-vehicle receiver according to another embodiment of the present invention. In FIG. 2, the same parts as in FIG. Is omitted. Reference numerals 12, 13, and 14 are first, second, and third comparator circuits for comparing with different reference voltages, and the FM input radio wave level signal of the one selected by each reference voltage and the switching signal from the AM / FM switching switch 8. 4 or AM
The input radio wave level signals 5 are compared with each other, and the comparison results are shown as the first, second and third control voltage output terminals 15, 16, 17
It outputs to each.

First, second and third control voltage output terminals 1
5, 16 and 17 are connected to a source of high frequency noise mounted in a vehicle in which the in-vehicle receiver R is mounted.

First, second and third comparator circuits 1
2, 13, 14 respectively compare the reference voltage with the FM input radio wave level signal 4 or the AM input radio wave level signal 5 and compare the result with the first, second and third control voltage output terminals. It outputs to each of 15, 16, and 17. That is, the reference voltage is the first, second, and third comparator circuits 1
2, 13 and 14 are different from each other, the input radio wave level is divided into three stages, and the three signals are high frequency by the first, second and third comparator circuits 12, 13 and 14 according to the input radio wave level. Transmit to the source of noise.

Thus, the operation of the high-frequency noise source is variably controlled according to the input radio wave level of the on-vehicle receiver R within a range that does not interfere with the on-vehicle receiver R.

Although the three comparator circuits are used in the above embodiment, the number of the comparator circuits may be increased to more finely control the generation source of the high frequency noise according to the input radio wave level. Further, although the input is switched inside the comparator circuit, a common single switch circuit may be provided in the preceding stage of the comparator to switch the input to the comparator.

[0021]

As described above, according to the present invention, the signal corresponding to the level of the input radio wave of the desired reception frequency is compared with the reference voltage to output the signal for controlling the operation of the high frequency noise source. Since it is configured, it is less likely to be disturbed by high frequency noise, and the reception state can be kept good.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a vehicle-mounted receiver according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a vehicle-mounted receiver according to another embodiment of the present invention.

[Explanation of symbols]

2 FM signal processing circuit 3 AM signal processing circuit 4 FM input radio wave level signal 5 AM input radio wave level signal 6, 12, 13, 14 Comparator circuit (comparison means) 7, 15, 16, 17 Control voltage output terminal (comparison means) ) 8 AM / FM selector switch 9 Volume / sound quality adjustment circuit 10 Power amplifier R In-vehicle receiver

Claims (1)

[Claims] 1. An in-vehicle receiver for converting an input radio wave having a desired reception frequency into a reception signal and outputting the received signal, compares a signal having a magnitude corresponding to the level of the input radio wave with a reference voltage, and externally compares the signals. An in-vehicle receiver, comprising: a comparison unit that outputs a control signal for controlling the operation of the high-frequency noise generation source so as not to be disturbed by the high-frequency noise generation source.