JP2002217757A - Receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a receiver that can cope with even a noise from electric components intruded from parts other than an antenna. SOLUTION: The receiver provided with reception sections 100, 101 receiving a broadcast radio wave and reception strength detection means 9, 20 that detect strength of a received signal on the basis of output signals from the reception sections 100, 101, is equipped with noise detection means 10, 21 that are connected to the reception strength detection means 9, 20 to detect a ripple voltage of the reception strength detection means 9, 20 and with noise canceller means 8, 19 that are forcibly operated on the basis of a noise detection signal outputted from the noise detection means 10, 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a receiver, and more particularly, to a receiver capable of removing noise entering a receiving circuit.

[0002]

2. Description of the Related Art FIG. 7 is a block diagram showing a schematic configuration of a conventional super-heterodyne receiver. In the figure, reference numeral 1 denotes an antenna for receiving a radio wave, and the radio wave taken from the antenna 1 is input to an input circuit 2A and a high-frequency amplifier circuit 2B
Is selected and amplified. The signal selectively amplified by the high-frequency amplifier circuit 2B and the local oscillation signal from the local oscillation circuit 3 are:
The signals are mixed by the mixer circuit 4 and extracted as an intermediate frequency signal. The intermediate frequency signal from the mixer circuit 4 is extracted by the band pass filter 5 as a signal in a predetermined frequency band. The intermediate frequency signal that has passed through the band-pass filter 5 is amplified by an intermediate frequency amplifying circuit 6, and the amplified intermediate frequency signal is demodulated into a sound signal before modulation by a detection circuit 7, and the detected signal is passed through a noise canceller circuit 8. It is output to the constituent switch circuit 8a. The output signal from the switch circuit 8a is formed into an audio signal without distortion by correcting the waveform by the waveform compensating circuit 40, and the output of the signal is output to the low frequency
The signal is amplified by 1 and a sound is output from the speaker 42.

The noise canceller circuit 8 includes a switch circuit 8a and a noise detector 8c.
The noise detection unit 8c includes a noise amplification circuit 8d, a noise detection circuit 8e, and a pulse generation circuit 8f. The intermediate frequency signal that has passed through the bandpass filter 5 is branched and input. The signal input to the noise detection unit 8c is amplified by the noise amplification circuit 8d with a frequency bandwidth that responds to the noise pulse, and the noise detection circuit 8e detects the noise component, extracts the noise component, and extracts the noise pulse signal. To form Then, the formed noise pulse signal is input to the pulse generation circuit 8f, forms a switching pulse according to the noise pulse signal, and sends out the switching pulse to the switch circuit 8a.

The switch circuit 8a cuts off the detection signal output from the detection circuit 7 based on the switching pulse signal output from the noise detection section 8c, and disconnects the detection signal at the time of noise detection to include the detection signal in the detection signal. To remove noise components.

The detection signal that has passed through the switch circuit 8a is
If the detected signal has a discontinuous waveform, the signal is amplified by a low-frequency amplifier 41 via a waveform compensating circuit 40 for correcting the detected signal into a continuous waveform, and is output from a speaker 42 as sound.

[0006]

Conventionally, measures against noise on the radio receiver side have been made using the above-described noise canceller.
It has been performed using circuits, but has the following problems.
Since the noise canceller circuit does not operate unless noise appears at the noise detection point of the noise detection circuit for detecting noise, there is a problem that almost no countermeasures are taken against noise entering from other than the antenna. there were.

Since the noise canceller circuit is designed to take measures against pulse noise, the noise canceller circuit has a noise canceller with respect to continuous noise and irregular noise waveforms.
Since the function is generally turned off, there has been a problem that sufficient measures have not been taken against continuity noise or noise having an irregular waveform.

On the other hand, countermeasures against electric system noise on the vehicle side, for example, noise entering the receiver from the electric system circuit due to the operation of an electric mirror, a power window, etc., are generally implemented by an electric system noise source. Was to insert a filter into the output section. However, there are many electrical noise sources on the vehicle side, and there are many parts where noise sources are uncertain.If filters are inserted in all noise sources, the circuit configuration becomes complicated and large. However, there is a problem that this is not a desirable measure in terms of shape and size and cost.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has as its object to provide a receiver capable of taking measures against electrical noise entering from other than an antenna.

[0010]

In order to achieve the above object, a receiver (1) according to the present invention comprises a receiving section for receiving a radio wave, and a receiving intensity based on an output signal from the receiving section. In a receiver provided with a reception intensity detecting means for detecting the noise level, a noise detection means connected to the reception intensity detection means and detecting a ripple voltage of the reception intensity detection means,
A noise canceling means for forcibly operating based on a noise detection signal output from the noise detecting means.

According to the receiver (1), the noise detection means for detecting the ripple voltage of the reception intensity detection means and the noise canceller means forcibly operating based on the noise detection signal output from the noise detection means are provided. Since the noise detection means detects a ripple voltage of the reception intensity detection means which becomes larger than normal when electric system noise occurs, the noise cancellation means is forcibly activated based on the detection signal. The noise canceller can prevent the noise level from being erroneously detected when a ripple voltage is generated in the reception intensity detector. Then, the noise canceller can be reliably operated, and it is possible to cope with electrical system noise entering from other than the antenna, and the noise can be reliably removed or reduced.

[0012] A receiver (2) according to the present invention is a receiver comprising: a receiving unit that receives a radio wave; and a receiving intensity detecting unit that detects a receiving intensity based on an output signal from the receiving unit. A noise detecting means connected to the receiving intensity detecting means for detecting a ripple voltage of the receiving intensity detecting means; and a soft mute means operating based on a noise detecting signal output from the noise detecting means. It is characterized by:

According to the receiver (2), the noise detecting means for detecting the ripple voltage of the receiving intensity detecting means and the soft mute means operating based on the noise detecting signal output from the noise detecting means are provided. The noise detection means detects a ripple voltage of the reception intensity detection means which becomes larger than normal when electric system noise occurs, and activates the soft mute means based on the detection signal. This can prevent erroneous detection of the electric field level of the soft mute means when a ripple voltage is generated in the reception intensity detection means. Then, the soft mute means can be operated reliably, and it becomes possible to cope with electrical system noise entering from other than the antenna, and the noise can be reliably removed or reduced.

[0014] A receiver (3) according to the present invention is a receiver including a receiver for receiving radio waves, and a power supply circuit for supplying a power supply voltage to the receiver, the receiver being connected to the power supply circuit. A power supply noise detecting means for detecting a power supply ripple of the power supply circuit; and a noise canceller means forcibly operating based on a noise detection signal output from the power supply noise detecting means.

According to the receiver, the power supply noise detecting means for detecting the power supply ripple of the power supply circuit and the noise canceller means forcibly operating based on the noise detection signal output from the power supply noise detecting means are provided. Since the power supply noise is provided, the power supply noise detection unit can detect a power supply ripple when electric system noise occurs, a noise input from a power supply line, or a power supply ripple accompanying a change in a power supply voltage or a load current. The noise canceller means can be forcibly operated based on the detection signal,
It is possible to cope with electrical system noise entering from other than the antenna, and it is possible to reliably remove or reduce the noise.

A receiver (4) according to the present invention is a receiver including a receiver for receiving radio waves, and a power supply circuit for supplying a power supply voltage to the receiver, the receiver being connected to the power supply circuit. Power supply noise detecting means for detecting a power supply ripple of the power supply circuit; and soft mute means operating based on a noise detection signal output from the power supply noise detecting means.

According to the receiver (4), the power supply noise detecting means for detecting the power supply ripple of the power supply circuit, and the soft mute means operating based on the noise detection signal output from the power supply noise detecting means. Since the power supply noise detecting means is provided, the power supply noise detection means can detect a power supply ripple when electric system noise occurs, a noise input from a power supply line, or a power supply ripple accompanying a change in a power supply voltage or a load current. The soft mute means can be operated based on the detection signal, and it is possible to cope with electrical system noise entering from other than the antenna, so that the noise can be reliably removed or reduced.

[0018] A receiver (5) according to the present invention is a receiver provided with a receiver for receiving radio waves, and a battery power supply for supplying a power supply voltage to the receiver, wherein the receiver is connected to the battery power. A battery power supply noise detecting means for detecting a ripple voltage of the battery power supply, and a noise canceller means forcibly operating based on a noise detection signal output from the battery power supply noise detecting means.

According to the receiver (5), a battery power supply noise detecting means for detecting a ripple voltage of the battery power supply, and a noise canceller forcibly operating based on a noise detection signal output from the battery power supply noise detecting means.
Means, the battery power supply noise detection means can detect a battery power supply ripple when electrical system noise occurs, and can operate the noise canceller means based on the detection signal. Therefore, it is possible to cope with electrical system noise entering from other than the antenna, and it is possible to reliably remove or reduce the noise.

A receiver (6) according to the present invention is a receiver including a receiver for receiving radio waves, and a battery power supply for supplying a power supply voltage to the receiver, the receiver being connected to the battery power. A battery power supply noise detecting means for detecting a ripple voltage of the battery power supply; and a soft mute means operating based on a noise detection signal output from the battery power supply noise detecting means.

According to the receiver, the battery power supply noise detecting means for detecting the ripple voltage of the battery power supply, and the soft mute means operating based on the noise detection signal output from the battery power supply noise detecting means. Therefore, the battery power noise detection means can detect the ripple voltage of the battery power when electrical system noise occurs, and operate the soft mute means based on the detection signal. Therefore, it is possible to cope with electrical system noise entering from other than the antenna, and the noise can be reliably removed or reduced.

A receiver (7) according to the present invention is a receiver provided with a receiving unit for receiving radio waves, wherein: an electric system circuit connected to a power supply for supplying a power supply voltage; And a noise canceller for forcibly operating based on an energization detection signal output from the energization detection means.

According to the receiver (7), an electric system circuit connected to a power supply, energization detecting means for detecting energization from the power supply to the electric system circuit, and an energization output by the energization detecting means Noise canceller means for forcibly operating based on the detection signal, so that the noise canceller means interlocks with energization from the power supply to the electrical system circuit.
The means can be forcibly operated, and the electrical system noise entering the receiving circuit can be reliably removed or reduced by the operation of the electrical system circuit. In addition, an effective measure can be taken against electrical system noise entering from other than the antenna without increasing the circuit configuration in complexity and size, and without increasing the cost.

A receiver (8) according to the present invention is a receiver provided with a receiving section for receiving radio waves, wherein: an electrical system circuit connected to a power supply for supplying a power supply voltage; The present invention is characterized in that it comprises an energization detecting means for detecting energization of the power supply, and a soft mute means forcibly operating based on an energization detection signal output from the energization detection means.

According to the receiver (8), an electric system circuit connected to a power supply, energization detecting means for detecting energization from the power supply to the electric system circuit, and energization output by the energization detecting means Since soft mute means forcibly operating based on the detection signal is provided, the soft mute means can be operated in conjunction with energization of the electric circuit from the power supply, and the electric circuit can be operated. By the operation, noise entering the receiving circuit can be reliably removed or reduced. Also, effective measures can be taken against electrical system noise that enters from other than the antenna without increasing the complexity and size of the circuit configuration and without increasing the cost.

The receiver (9) according to the present invention is characterized in that, in the receiver (7) or (8), the electric system circuit is an electric mirror drive circuit. According to the receiver (9), since the electric system circuit is an electric mirror drive circuit, the electric system system enters the reception circuit in conjunction with the operation of the electric mirror drive circuit during operation of the electric mirror. Noise can be reliably removed or reduced.

A receiver (10) according to the present invention is characterized in that, in the receiver (7) or (8), the electric system circuit is a power window drive circuit.
According to the receiver (10), the electric system circuit is powered.
Since it is a window drive circuit, it is possible to reliably remove or reduce the electrical system noise entering the receiving circuit in conjunction with the operation of the power window drive circuit during the operation of the power window.

Further, the receiver (11) according to the present invention is characterized in that, in the receiver (7) or (8), the electric system circuit is a Sanlf drive circuit. According to the receiver (11), since the electrical system circuit is a sun roof driving circuit, the electrical system system enters the receiving circuit in conjunction with the operation of the sun roof driving circuit during the operation of the sun roof. Noise can be reliably removed or reduced.

The receiver (12) according to the present invention is characterized in that, in the receiver (7) or (8), the electric system circuit is a wiper drive circuit. According to the receiver (12), since the electrical system circuit is the wiper drive circuit, the electrical system noise entering the receiver circuit during the operation of the wiper in conjunction with the operation of the wiper drive circuit can be reliably prevented. Can be reduced or reduced.

The receiver (13) according to the present invention is characterized in that, in the receiver (7) or (8), the electric system circuit is a washer drive circuit. According to the receiver (13), since the electrical system circuit is a washer drive circuit, the electrical system noise entering the receiver circuit in conjunction with the operation of the washer drive circuit during the washer-liquid injection is reduced. It can be reliably removed or reduced.

A receiver (14) according to the present invention is characterized in that, in the receiver (7) or (8), the electric system circuit is a power sheet drive circuit. According to the receiver (14), the electric circuit is a power
Since the driving circuit is a self-driving circuit, it is possible to reliably remove or reduce electric system noise entering the receiving circuit in conjunction with the operation of the power sheet driving circuit during the adjustment of the seat position.

The receiver (15) according to the present invention is characterized in that, in the receiver (7) or (8), the electric system circuit is an auto-antenna driving circuit. According to the receiver (15), since the electrical system circuit is an auto-antenna driving circuit, it enters the receiving circuit in conjunction with the operation of the auto-antenna driving circuit during the operation of the auto-antenna. The coming electrical system noise can be reliably removed or reduced.

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the receiver according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of a receiver according to Embodiment (1) of the present invention. Note that, in the embodiment of the present invention, AM
The description will be made by taking an example of an in-vehicle radio receiver that can receive both broadcast waves of FM and FM.

The antenna 1 is for receiving radio broadcast radio waves, and a high frequency signal of a predetermined frequency in the AM broadcast radio waves taken into the antenna 1 is amplified by the AM high frequency amplifier circuit 2. The signal amplified by the AM high-frequency amplifier circuit 2 and the local oscillation signal generated by the AM local oscillation circuit 3 are mixed by the AM mixer circuit 4, converted into an AM intermediate frequency signal having a center frequency of about 450 kHz, and extracted. From the signal output from the AM mixer circuit 4, only an AM intermediate frequency signal in a predetermined frequency band is extracted by an AM bandpass filter 5. The AM intermediate frequency signal extracted by the AM band pass filter 5 is supplied to an AM intermediate frequency amplifier circuit 6.
The amplified signal is detected by the AM detection circuit 7, and the audio signal and noise pulse before modulation are output.
Switch circuit 8 constituting M noise canceller circuit 8
a.

The antenna 1, AM high-frequency amplifier circuit 2, AM local oscillation circuit 3, AM mixer circuit 4,
An AM receiving section 100 is composed of the M band pass filter 5, the AM intermediate frequency amplification circuit 6, and the AM detection circuit 7.

The output side of the AM intermediate frequency amplifying circuit 6 is connected to a high-pass filter 8b which branches and forms an AM noise canceller circuit 8, and an S-meter circuit 9. The AM noise detector 8c is connected to the high-pass filter 8b, and the S-meter circuit 9 is connected to the S-meter for AM.
The S-meter for AM is connected to the
The noise detection circuit 10 is connected via an OR circuit 11 to the AM noise detection section 8c of the AM noise canceller circuit 8. The AM noise detector 8c is connected to the switch circuit 8
a, and a switching pulse corresponding to the noise pulse signal detected by the AM noise detector 8c is output to the switch circuit 8a.

When the intermediate frequency is correctly tuned to a predetermined frequency, the S-meter circuit 9 (not shown) provides an S-meter (not shown).
Is the maximum, and it is intended to detect whether or not the receiving state is the best. The S-meter circuit 9 has an AM
The intermediate frequency signal is amplified and rectified by a voltage doubler circuit to produce a DC voltage, and this DC voltage is passed through a sensitivity adjuster to an S-meter.
(Not shown).

The S-meter noise detection circuit for AM 10
A high-pass filter 10a that passes only high-frequency noise components (ripple voltage) included in the DC voltage of the S-meter circuit 9 and a noise detector 10b that detects a ripple voltage based on a filtered signal filtered by the high-pass filter 10a. It is comprised including. The noise detector 10b may be configured to rectify and smooth the filtered signal with a rectifier / smoothing circuit to detect noise. When noise (generation of ripple voltage) is detected by the noise detection unit 10b, a noise detection signal for forcibly operating the AM noise canceller circuit 8 is output to the AM noise detection unit 8c via the OR circuit 11, and the AM noise canceller is output. The circuit 8 is forcibly operated, and the switch circuit 8a is turned off while noise is detected.

From the AM detection signal that has passed through the switch circuit 8a, a noise component contained in the detection output signal is removed.
Only the AM detection signal from which the noise component has been removed is amplified by a low-frequency amplifier circuit (not shown) and output as a sound from a speaker (not shown).

In the figure, reference numeral 12 denotes an FM high-frequency amplifier circuit for amplifying a high-frequency signal of a predetermined frequency in the FM broadcast radio wave input to the antenna 1. FM high frequency amplifier circuit 1
2 and the local oscillation signal generated from the FM local oscillation circuit 13 are mixed in the FM mixer circuit 14,
It is converted into an intermediate frequency signal of about 10.7 MHz and extracted. From the signal output from the FM mixer circuit 14, only the FM intermediate frequency signal in a predetermined frequency band is extracted by the FM bandpass filter 15. The FM intermediate frequency signal extracted by the FM band pass filter 15 is amplified by an FM intermediate frequency amplifying circuit 16, and the amplified signal is
7, the detected signal is connected so as to be inputted to an amplifier circuit 18a constituting the soft mute circuit 18.

The antenna 1, FM high-frequency amplifier circuit 12, FM local oscillation circuit 13, FM mixer circuit 1
4, an FM bandpass filter 15, an FM intermediate frequency amplification circuit 16, and an FM detection circuit 17 constitute an FM reception unit 101.

The output side of the FM intermediate frequency amplification circuit 16 is branched and connected to the S-meter circuit 20.
The S-meter circuit 20 detects whether or not the output of the S-meter (not shown) is maximized when the intermediate frequency is correctly tuned to 10.7 MHz and the reception state is optimal. The circuit configuration is the S-meter of the AM receiving circuit.
The configuration may be similar to that of the circuit 9.

The S-meter circuit 20 branches to the muting control section 18b of the soft mute circuit 18 and the FM
Connected to the S-meter noise detection circuit 21 for use.
The muting control unit 18b is connected to the amplifying circuit 18a, and controls the muting operation of the detection signal in the amplifying circuit 18a based on the drive signal from the muting control unit 18b.

The FM S-meter noise detection circuit 21
It has a circuit configuration similar to that of the S-meter noise detection circuit 10 for AM, and includes a high-pass filter 21a and a noise detection unit 21b.
It is comprised including. And S-meter for FM
The noise detection circuit 21 is connected to an FM noise detection unit 19c of the noise canceller circuit 19 via an OR circuit 22.

The output side of the amplifier circuit 18a is connected to a switch circuit 19a and a high-pass filter 19b constituting a noise canceller circuit 19, and the high-pass filter 19b is connected to an FM noise detecting section 19c, and is connected to an FM noise detecting section 19c. Is connected to the switch circuit 19a,
The operation of the switch circuit 19a is controlled by a switching pulse output from the FM noise detection unit 19c, and the switch circuit 19a is turned off while noise is detected.

By the FM noise canceller circuit 19,
A noise component included in the detection output signal is removed, and only the FM detection signal from which the noise component has been removed is amplified by a low-frequency amplifier (not shown) and output as a voice from a speaker (not shown). You.

A battery power supply 23 is connected to an AM power supply circuit 25 via a power supply line 24 for supplying power.
It is connected to the M power supply circuit 26. A battery power supply noise detection circuit 27 is connected to the battery power supply 23, an AM power supply noise detection circuit 28 is connected to the AM power supply circuit 25, and an FM power supply noise detection circuit 29 is connected to the FM power supply circuit 26. The AM power supply noise detection circuit 28 and the battery power supply noise detection circuit 27 are connected to the AM noise detection section 8c of the AM noise canceller circuit 8 via the OR circuit 11, and the FM power supply noise detection circuit 29
And the battery power supply noise detection circuit 27
Is connected to the FM noise detection unit 19c of the FM noise canceller circuit 19 via the.

The battery power supply noise detection circuit 27 includes a high-pass filter 1 that passes only a high-frequency noise component (ripple voltage) included in the DC voltage of the battery power supply 23.
0a and a noise detection unit 10b for detecting a ripple voltage based on the filtered signal filtered by the high-pass filter 10a. Similarly, the AM power supply noise detection circuit 28 includes the high-pass filter 28a and the noise detection unit 2
8b, and the FM power supply noise detection circuit 29
Also includes a high-pass filter 29a and a noise detector 29b. Each noise detector 27a to 29a
May be configured such that the filtered signal is rectified and smoothed by a rectifying / smoothing circuit to detect noise.

Before explaining the operation of the receiver shown in FIG. 1, the general relationship between the input electric field level of radio waves received from the antenna and the S level (S meter output voltage) will be described. Explanation will be made based on the schematic diagram shown in FIG.

The S level has a characteristic that increases as the input electric field level increases. Also, noise canceller
The circuit is normally activated when the input electric field level is below a predetermined value. This is because, as the input electric field level is lower, the noise in the audio signal is relatively emphasized, so that the necessity of removing the noise increases.

When the electrical system noise accompanying the operation of the electrical system circuit mounted on the vehicle enters the receiving circuit, the ripple voltage of the DC voltage of the S-meter circuit becomes larger than usual.

When the S-meter circuit is used as a sensor for ON / OFF control of the noise canceller circuit, that is, in the case of a noise canceller circuit that detects the level of the input electric field from the antenna at the S level, for example, the electrical equipment circuit switches to the electrical equipment. When system noise occurs and the ripple voltage in the S-meter circuit increases, the actual input electric field level from the antenna is not high, but only the S level is increased. It is erroneously detected that the input electric field level from the antenna is high. Noise canceller
The circuit is controlled to be OFF and does not operate, and the electrical system noise is mixed into the audio signal, so that harsh audio is reproduced.

In order to prevent this, in the receiver according to the embodiment (1), when the S-meter circuits 9 and 20 detect the ripple voltage, the noise canceller circuits 8 and 19 are forcibly activated. I did it. Similarly, when the power supply ripple of the AM power supply circuit 25 is detected, the FM power supply circuit 2
In order to forcibly operate the noise canceller circuits 8 and 19 even when the power supply ripple in the power supply 6 is detected or the ripple voltage of the battery power supply 23 is detected. The configuration is such that the noise canceller circuits 8, 19, which have been effective against incoming noise, can also be used for measures against electrical system noise entering from other than the antenna 1.

The operation of the receiver according to the embodiment (1) when an electric component mounted on the vehicle, for example, an electric mirror, a power window or the like is operated during reception of a broadcast wave will be described. Note that the method of receiving the broadcast wave from the antenna 1 is the same as that of the conventional receiver shown in FIG. 7, and therefore the description thereof is omitted here, and the operation of the characteristic portion will be described below.

For example, when the AM S-meter noise detection circuit 10 detects a ripple voltage generated in the S-meter circuit 9 during AM broadcast reception, the noise detection signal is output via the OR circuit 11 to AM of AM noise canceller circuit 8
The signal is output to the noise detector 8c. The AM noise canceller circuit 8 which has received the noise detection signal is forced to operate, operates regardless of the detected S level or input electric field level, and reliably removes noise contained in the AM detection signal. become.

When the power supply ripple generated by the AM power supply circuit 25 is detected by the AM power supply noise detection circuit 28, the noise detection signal is output to the AM noise detection section 8c of the AM noise canceller circuit 8 via the OR circuit 11. Then, the AM noise canceller circuit 8 is forcibly operated, and A
Noise contained in the M detection signal is reliably removed.

On the other hand, during the FM broadcast reception, the S-meter circuit 2
When the FM S-meter noise detection circuit 21 detects the ripple voltage generated at 0, the noise detection signal is output to the FM noise canceller circuit 8 through the OR circuit 22.
The signal is output to the noise detector 19c. Upon receiving the noise detection signal, the FM noise canceller circuit 19 is forcibly activated, operates regardless of the detected S level or input electric field level, and reliably removes noise contained in the FM detection signal. Become.

When the power supply ripple generated by the FM power supply circuit 26 is detected by the FM power supply noise detection circuit 29, the noise detection signal is output to the FM circuit via the OR circuit 22.
FM noise detector 19c of noise canceller circuit 19
And forcibly operates the FM noise canceller circuit 19 to reliably remove noise contained in the FM detection signal.

Further, when the battery power supply noise detection circuit 27 detects the power supply ripple generated in the battery power supply 23, if the AM reception is being performed, the noise detection signal is sent to the AM noise canceller circuit 8 of the AM noise canceller circuit 8 via the OR circuit 11.
The signal is output to the noise detection unit 8c, and when FM reception is being performed, the noise detection signal is output to the FM noise detection unit 19c of the FM noise canceller circuit 19 via the OR circuit 22. And AM or FM receiving the noise detection signal
The noise canceller circuit is forcibly activated,
It operates regardless of the detected S level or input electric field level, and reliably removes noise contained in the AM or FM detection signal.

According to the receiver of the embodiment (1), the ripple voltage of the S-meter circuits 9 and 20, which becomes larger than normal when the electrical system noise occurs, is reduced by the S-meter.
The noise canceler circuits 8 and 19 can be forcibly operated based on the detection signals, and when a ripple voltage is generated in the S-meter circuits 9 and 20. Noise canceller circuits 8, 1
9 can prevent erroneous detection of the electric field level.

Further, the power supply noise detection circuits 28 and 29 can detect power supply ripple when electric system noise occurs, noise input from a power supply line, or power supply ripple accompanying a change in power supply voltage or load current. The noise canceller circuits 8, 19 can be forcibly operated based on the detection signal. In addition, the battery power supply noise detection circuit 27 can detect a battery power supply ripple when electrical system noise occurs, and can forcibly operate the noise canceller circuits 8 and 19 based on the detection signal.

Accordingly, it is possible to cope with the electrical system noise entering from other than the antenna 1 so that the noise does not enter, and it is possible to reliably remove or reduce the noise.

Next, a receiver according to Embodiment (2) of the present invention will be described. FIG. 3 is a block diagram showing a schematic configuration of a receiver according to Embodiment (2) of the present invention. Components having the same functions as those of the receiver according to Embodiment (1) shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

The difference between the receiver according to the embodiment (2) shown in FIG. 3 and the receiver according to the embodiment (1) shown in FIG. Is output to the noise canceller circuit 19,
As a configuration for outputting to the soft mute circuit 18 to operate the soft mute circuit 18, the soft mute circuit 18 which has conventionally been effective for countermeasures against noise in a weak electric field is provided.
Can be used also as a measure against electrical system noise entering from other than the antenna 1.

That is, in FIG. 3, the S-mail for FM
The noise detection signals from the noise detection unit 21b of the power noise detection circuit 21, the noise detection unit 27b of the battery power supply noise detection circuit 27, and the noise detection unit 29b of the FM power supply noise detection circuit 29 are soft muted through the OR circuit 22.
The output is provided to the muting control section 18b of the remote circuit 18.

The soft mute circuit 18 includes a muting control section 18b and an amplifier circuit 18a. The muting control unit 18b extracts a carrier from the intermediate frequency signal amplified by the FM intermediate frequency amplifying circuit 16, amplifies the carrier with an amplifier, rectifies the carrier with a rectifier circuit to generate a DC voltage, and mutes the DC voltage with the DC voltage. The driving control circuit is driven to control the operation of the amplifier circuit 18a.

Next, electric components mounted on the vehicle, for example,
The operation of the receiver according to the embodiment (2) when the electric mirror or the power window is activated during reception of FM broadcast radio waves will be described.

During the FM broadcast reception, the ripple voltage generated in the S-meter circuit 20 is reduced by the operation of the electrical system circuit.
When the S-meter noise detection circuit 21 detects the noise, the noise detection signal is output to the muting control section 18b of the soft mute circuit 18 via the OR circuit 22. The soft mute circuit 18, which has detected the noise detection signal, activates the muting control section 18b to amplify the amplifier circuit 18a.
Is controlled (for example, the amplification degree of the amplifier circuit 18a is reduced) to control the level of the FM detection signal after the output of the FM detection circuit 17 to reliably remove or reduce noise included in the FM detection signal.

When the battery power supply noise detection circuit 27 detects a ripple voltage generated in the battery power supply 23, the noise detection signal is output to the muting control section 18b of the soft mute circuit 18 via the OR circuit 22. Then, the soft mute circuit 18 is forcibly operated to reliably remove or reduce noise contained in the FM detection signal.

Further, when the power supply noise detection circuit 29 detects the power supply ripple generated in the FM power supply circuit 26,
This noise detection signal is output to the muting control section 18b of the soft mute circuit 18 via the OR circuit 22, and the soft mute circuit 18 is forcibly operated to reliably remove or reduce noise contained in the FM detection signal. Will be.

As described above, when a ripple voltage or a power supply ripple occurs in any of the S-meter circuit 20, the battery power supply 23, or the FM power supply circuit 26 and is detected as noise by the noise detection circuit, the soft muting is performed. The noise detection signal for driving the gate circuit 18 to the OR circuit 22
The signal is output to the soft mute circuit 18 via the control circuit and the soft mute circuit 18 is operated.

According to the receiver according to the above embodiment (2), the ripple voltage of the S-meter circuit 20, which becomes larger than normal when the electrical system noise occurs, is reduced by the S-meter.
The noise is detected by the noise detection circuit 21 and the soft mute circuit 18 can be forcibly activated based on the detection signal. When the ripple voltage is generated in the S-meter circuit 20, the soft mute circuit 18 is activated. Erroneous detection of the electric field level can be prevented, and the soft mute circuit 18 can be operated reliably.

Further, the FM power supply noise detection circuit 29 can detect a power supply ripple when electric system noise occurs, a noise coming from a power supply line, or a power supply ripple accompanying a change in a power supply voltage or a load current. Then, the soft mute circuit 18 can be operated based on the detection signal. Also, the battery power supply noise detection circuit 27
Accordingly, it is possible to detect the battery power supply ripple when the electrical system noise occurs, and to operate the soft mute circuit 18 based on the detection signal.

Therefore, it is possible to cope with the electrical system noise so that the noise does not enter, and it is possible to reliably remove or reduce the noise.

In the receiver according to the embodiment (2) shown in FIG. 3, both the AM receiving circuit and the FM receiving circuit are substantially the same as the receiver according to the embodiment (1) shown in FIG. As a configuration, a soft mute circuit 1 is provided only on the FM receiving circuit side.
Although a configuration is provided in which the soft mute circuit is provided on the AM receiving circuit side, the same effect can be obtained.

Next, a receiver according to Embodiment (3) of the present invention will be described. FIG. 4 is a block diagram showing a schematic configuration of a receiver according to Embodiment (3) of the present invention. Note that components having the same functions as those of the receiver according to Embodiment (2) shown in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted.

The difference between the receiver according to the embodiment (3) shown in FIG. 4 and the receiver according to the embodiment (2) is that
S-meter circuit 9 of AM receiving circuit, S-meter circuit 20 of FM receiving circuit, AM power circuit 25, FM power circuit 2
6, and the configuration in which the noise detection circuit is provided in each of the battery power supplies 23 is a configuration in which the function is integrated into one noise detection circuit 30.

The following description focuses on differences from the receiver according to the embodiment (2). In FIG. 4, the noise detection circuit 30 can have a circuit configuration substantially similar to the noise detection circuit such as the AM S-meter noise detection circuit 10 in FIG. 3 described above, and includes a high-pass filter 30a and a noise detection unit. 30b.

High-pass filter 3 of noise detection circuit 30
0a denotes an S-meter circuit 9 on the AM side, an S-meter circuit 20 on the FM side, a battery power supply 23, an AM power supply circuit 25, and an FM power supply circuit 26 for detecting a ripple voltage or a power supply ripple. Are connected to each other. The high-pass filter 30a filters only a high-frequency noise component (ripple voltage or power supply ripple) included in the DC voltage from each of the circuits, and based on the filtered signal, performs noise (ripple voltage or ripple voltage) at the noise detection unit 30b. (Power supply ripple), and outputs a noise detection signal to the AM noise canceller circuit 8 or the soft mute circuit 1.
8 to be output.

For example, during AM broadcast reception, the noise detection circuit 30 detects any one of the ripple voltage in the S-meter circuit 9, the power supply ripple in the AM power supply circuit 25, and the ripple voltage in the battery power supply 23. When it is detected, the noise detection signal is output to the AM noise detection unit 8c of the AM noise canceller circuit 8, and the AM noise canceller circuit 8 is forcibly activated, so that the electrical system noise included in the AM detection signal is also reliably removed. Or reduce it.

During FM broadcast reception, the noise detection circuit 30 detects any one of the ripple voltage in the S-meter circuit 20, the power supply ripple in the FM power supply circuit 26, and the ripple voltage in the battery power supply 23. If detected, the noise detection signal is muted by the soft mute circuit 18.
Output to the switching controller 18b, and the soft mute circuit 1
8 is forcibly operated to reliably remove or reduce the electrical system noise included in the FM detection signal.

According to the receiver of the above embodiment (3), the same effects as those of the receivers of the above embodiments (1) and (2) can be obtained, and the noise detection circuit can be obtained. Since the circuits 30 are integrated into one, the circuit configuration does not become complicated and large, the cost can be reduced, and it is possible to cope with electrical system noise, and the noise can be reliably removed or reduced.

Next, a receiver according to Embodiment (4) of the present invention will be described. FIG. 5 is a block diagram showing a schematic configuration of a receiver according to Embodiment (4) of the present invention. The components having the same functions as those of the receiver according to the embodiment (1) shown in FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted. Only the features will be described.

In the receivers according to the above embodiments (1) to (3), a ripple voltage or a power supply ripple generated in each circuit which influences when an electrical system noise occurs is detected, and the noise canceller is forcibly detected. -It was characterized in that the circuit or the soft mute circuit was activated. The receiver according to the embodiment (4) is characterized in that the noise canceller circuit is forcibly operated in conjunction with energization of an electrical system circuit which directly affects the generation of electrical system noise.

As shown in FIG. 5, the electric system circuits mounted on the vehicle include an electric mirror driving circuit 32a, a power window driving circuit 32b, a sun roof driving circuit 32c, a wiper driving circuit 32d, and a washer driving circuit. Circuit 32e,
A power-sheet drive circuit 32f, an auto-antenna drive circuit 32g, and the like are provided. When power is supplied by turning on the operation switches 33a to 33g of each drive circuit as power supply detection means, the power supply detection signal becomes OR. AM via circuit 31
The AM noise detector 8c of the noise canceller circuit 8 or the FM noise detector 1 of the FM noise canceller circuit 19
9c.

The operation of the receiver during AM broadcast reception will be described. For example, when the power window operation switch 33b is turned ON to open and close the window, the power is supplied to the power window drive circuit 32b in conjunction with the power supply. Detection signal is OR
AM of the AM noise canceller circuit 8 via the circuit 31
The signal is output to the noise detector 8c.

Then, the AM noise canceller circuit 8 which has taken in the energization detection signal forcibly enters an operating state, and reliably removes noise entering the AM receiving circuit from the power window driving circuit 23b.

Similarly, during FM broadcast reception,
If any one of the electrical system circuits 32a to 32g is driven by the ON operation of each of the operation switches 33a to 33g, the energization detection signal becomes O in conjunction with the energization to the electrical system circuits 32a to 32g.
The FM noise canceller circuit 19, which is output to the FM noise detector 19c of the FM noise canceller circuit 19 via the R circuit 31 and captures the energization detection signal, forcibly enters an operating state, and receives a signal from the energized electrical system circuit. Therefore, the noise entering the device can be surely removed.

According to the receiver of the above-described embodiment (4), the electrical system circuit 32 connected to the battery power source 23
a to 32 g, and the electrical system circuit 32 a
Switches 33a to 33 that detect energization to
g, and a noise canceller forcibly operating based on the energization detection signals output by the operation switches 33a to 33g.
Since the circuits 8 and 19 are provided, the noise canceller circuits 8 and 19 can be forcibly operated in conjunction with the energization from the battery power supply 23 to the electrical circuits 32a to 32g, and the electrical circuits 32a to 32g can be operated. By the operation described above, the electrical system noise entering the receiving circuit can be reliably removed or reduced. In addition, the circuit configuration does not become complicated and large, and effective measures can be taken at a low cost with respect to electrical system noise entering from other than the antenna 1.

Next, a receiver according to Embodiment (5) of the present invention will be described. FIG. 6 is a block diagram showing a schematic configuration of the receiver according to Embodiment (5) of the present invention. The receiver according to the embodiment (5) is different from the receiver according to the embodiment (4) in that an energization detection signal from each electrical system circuit is transmitted to a noise canceller via an OR circuit.
The output is not output to the circuit, but is output to the soft mute circuit to operate the soft mute circuit.

In FIG. 6, the embodiment shown in FIG. 5 is connected to the soft mute circuit 18 provided only on the FM receiving circuit side so as to receive the conduction detection signal from the OR circuit 31. Since the configuration is the same as that of the receiver according to mode (4), description thereof will be omitted.

The operation of the receiver during FM broadcast reception will be described. For example, when the operation switch 33a of the electric mirror drive circuit 32a is turned on to open and close the electric mirror, the power supply to the electric mirror drive circuit 32a is performed. In conjunction with this, an energization detection signal is output to the muting control section 18b of the soft mute circuit 18 via the OR circuit 31.

The muting control section 18b, which has received the energization detection signal, forcibly enters an operating state, and reliably removes electrical system noise entering the receiving circuit from the electric mirror drive circuit 32a. .

In FIG. 6, during the FM broadcast reception, any one of the electrical system circuits 32a to 32g is activated by the operation switch 33a.
If driven by an ON operation of ~ 33g, the electrical system circuit 32
An energization detection signal is output to the soft mute circuit 18 via the OR circuit 31 in conjunction with the energization of a to 32g.

According to the receiver of the above-described embodiment (5), the electrical system circuit 32 connected to the battery power source 23
a to 32 g, and the electrical system circuit 32 a
Switches 33a to 33 that detect energization to
g, and a soft mute circuit 18 forcibly operating based on the energization detection signals output from the operation switches 33a to 33g. The soft mute circuit 18 can be forcibly activated, and the electrical system noise entering the receiving circuit can be reliably removed or reduced by the operation of the electrical system circuits 32a to 32g. Further, the circuit configuration does not become complicated and large, and effective measures can be taken at low cost even for electrical system noise entering from other than the antenna 1.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of a receiver according to Embodiment (1).

FIG. 2 is a diagram schematically showing a relationship between an antenna input electric field level and an S-meter signal level (output voltage).

FIG. 3 is a block diagram illustrating a schematic configuration of a receiver according to Embodiment (2).

FIG. 4 is a block diagram showing a schematic configuration of a receiver according to Embodiment (3).

FIG. 5 is a block diagram showing a schematic configuration of a receiver according to Embodiment (4).

FIG. 6 is a block diagram showing a schematic configuration of a receiver according to Embodiment (5).

FIG. 7 is a block diagram illustrating a schematic configuration of a conventional receiver.

[Explanation of symbols]

 Reference Signs List 8 AM noise canceller circuit 8a switch circuit 8b high-pass filter 8c AM noise detector 9 S-meter circuit 10 S-meter noise detector for AM 11 OR circuit 18 soft mute circuit 18a amplifier circuit 18b muting control Unit 19 FM noise canceller circuit 19a Switch circuit 19b High pass filter 19c FM noise detection unit 20 S-meter circuit 21 S-meter noise detection circuit for FM 22 OR circuit 23 Battery power supply 24 Power supply line 25 AM power supply circuit 26 FM power supply Power supply circuit 27 Battery power supply noise detection circuit 28 AM power supply noise detection circuit 29 FM power supply noise detection circuit 100 AM receiver 101 FM receiver

Claims (15)

[Claims] 1. A receiver comprising: a receiving unit that receives a radio wave; and a receiving intensity detecting unit that detects a receiving intensity based on an output signal from the receiving unit, wherein the receiving unit is connected to the receiving intensity detecting unit, A receiver comprising: noise detection means for detecting a ripple voltage of reception intensity detection means; and noise canceller means forcibly operating based on a noise detection signal output from the noise detection means. 2. A receiver comprising: a receiving unit that receives a radio wave; and a receiving intensity detecting unit that detects a receiving intensity based on an output signal from the receiving unit, wherein the receiving unit is connected to the receiving intensity detecting unit, A receiver comprising: noise detection means for detecting a ripple voltage of reception intensity detection means; and soft mute means operating based on a noise detection signal output from the noise detection means. 3. A receiver comprising a receiver for receiving a radio wave and a power supply circuit for supplying a power supply voltage to the receiver, wherein the receiver is connected to the power supply circuit and detects a power supply ripple of the power supply circuit. A receiver comprising: power supply noise detection means; and noise canceller means forcibly operating based on a noise detection signal output from the power supply noise detection means. 4. A receiver comprising: a receiving section for receiving a radio wave; and a power supply circuit for supplying a power supply voltage to the receiving section, wherein the receiver is connected to the power supply circuit and detects a power supply ripple of the power supply circuit. A receiver comprising: power noise detection means; and soft mute means operating based on a noise detection signal output from the power noise detection means. 5. A receiver comprising: a receiver for receiving a radio wave; and a battery power supply for supplying a power supply voltage to the receiver, wherein the receiver is connected to the battery power and detects a ripple voltage of the battery power. A receiver comprising: battery power noise detection means; and noise canceller means forcibly operating based on a noise detection signal output from the battery power noise detection means. 6. A receiver comprising a receiver for receiving a radio wave, and a battery power supply for supplying a power supply voltage to the receiver, wherein the receiver is connected to the battery power and detects a ripple voltage of the battery power. A receiver comprising: battery power supply noise detection means; and soft mute means operating based on a noise detection signal output from the battery power supply noise detection means. 7. A receiver provided with a receiving unit for receiving a radio wave, an electric system circuit connected to a power supply for supplying a power supply voltage, and energization detecting means for detecting energization from the power supply to the electric system circuit. And a noise canceller for forcibly operating based on an energization detection signal output from the energization detection means. 8. A receiver provided with a receiver for receiving a radio wave, wherein: an electrical system circuit connected to a power supply for supplying a power supply voltage; and an energization detecting means for detecting energization from the power source to the electrical system circuit. And a software mute unit for forcibly operating based on the energization detection signal output from the energization detection unit. 9. The receiver according to claim 7, wherein the electric system circuit is an electric mirror drive circuit. 10. The receiver according to claim 7, wherein said electric system circuit is a power window drive circuit. 11. The receiver according to claim 7, wherein the electric system circuit is a sun-roof drive circuit. 12. The receiver according to claim 7, wherein said electric system circuit is a wiper drive circuit. 13. The receiver according to claim 7, wherein the electrical system circuit is a washer drive circuit. 14. The receiver according to claim 7, wherein said electric system circuit is a power sheet drive circuit. 15. The receiver according to claim 7, wherein said electrical system circuit is an auto-antenna drive circuit.