JPH08102692A - Receiving system for automobile - Google Patents

Abstract

PURPOSE: To reduce noises and to improve the SN ratio by connecting a filter for attenuating one or more required received frequency bands or required broadcasting frequency bands selected from a specific place to a receiver. CONSTITUTION: An antenna conductor is mounted on a glass plate of a rear window for an automobile, a received signal from the antenna conductor is sent to an AM radio 1 arranged in the vicinity of a driver's sheet through a coaxial cable, a channel is selected by the AM radio 1, and a speaker 3 arranged close to the glass plate of the rear window is driven by a low frequency amplifier part in the AM radio 1. In this case, a filter 2 for attenuating one or more required received frequency bands or required broadcasting frequency bands selected from inputs to the low frequency amplifier part in the receiver 1 is connected between the low frequency amplifier part of the receiver 1 and the speaker 3. Consequently an RF carrier component is attenuated and the probability of radiating the RF carrier component from a speaker cable, a power supply cable or the like as a radio wave can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle receiving system for reducing noise.

[0002]

2. Description of the Related Art An antenna conductor is provided on a glass plate of a rear window of an automobile, a reception signal from the antenna conductor is sent to a receiver provided near a driver's seat by a coaxial cable, and the receiver selects a receiver to select a receiver. A vehicle receiving system for driving a speaker provided in the vicinity of a glass plate of a rear window by the low frequency amplifier is generally known and implemented.

In such a conventional automobile receiving system,
Since the tuning frequency leaks from the connection cable (power cable) between the receiver and the power supply to the input of the low frequency amplification section of the receiver, the tuning frequency is amplified by the low frequency amplification section and the low frequency amplification section of the receiver Is output.

The tuning frequency component (RF carrier component) output from the low frequency amplification unit of the receiver becomes a radio wave from a connection cable (speaker cable) between the low frequency amplification unit of the receiver and the speaker, a power cable, or the like. And fly into the air, and are received by the antenna conductor on the glass plate of the rear window and become a noise component.

Particularly, when the speaker is provided near the glass plate of the rear window, the antenna conductor and the speaker cable are close to each other, so that the noise due to the RF carrier component tends to increase.

When a car is equipped with an audio device such as a CD deck in addition to the receiver, the RF carrier component caused by the receiver also becomes a radio wave from the speaker cable of the audio device. It may fly into the air and be received by the antenna conductor on the glass plate of the rear window, and become a noise component.

[0007]

DISCLOSURE OF THE INVENTION The present invention aims to solve the above-mentioned drawbacks of the prior art, and newly provides a receiving system for an automobile, which has not been heretofore known.

[0008]

DISCLOSURE OF THE INVENTION The present invention provides an automobile receiving system in which an antenna conductor is provided on a glass plate of a window of an automobile and a reception signal from the antenna conductor is sent to a receiver.
One or more desired reception frequency band or desired broadcast frequency selected from between the receiver and the power supply, between the low frequency amplification section of the receiver and the speaker, and the input of the low frequency amplification section of the receiver. Provided is a vehicle receiving system characterized by connecting a filter for attenuating a band.

Further, the present invention provides an automobile receiving system in which an antenna conductor is provided on a glass plate of a window of an automobile and a reception signal from the antenna conductor is sent to the receiver, between the receiver and the power supply and separately from the receiver. Between the provided audio equipment and the power supply, between the low frequency amplification section of the receiver and the speaker, between the low frequency amplification section of the audio equipment and the speaker, the input of the low frequency amplification section of the receiver, and the audio Provided is a vehicle receiving system characterized in that a filter for attenuating a desired reception frequency band or a desired broadcasting frequency band is connected to at least one selected from the input of a low frequency amplification section of the device.

Further, according to the present invention, in an automobile receiving system in which an antenna conductor is provided on a glass plate of a window of an automobile and a reception signal from the antenna conductor is sent to the receiver, a low receiver is provided between the receiver and a power supply. There is provided a receiving system for an automobile, wherein a filter for attenuating a tuning frequency is connected to at least one selected from a frequency amplifier and a speaker and an input of a low frequency amplifier of a receiver.

Further, the present invention is an automobile receiving system in which an antenna conductor is provided on a glass plate of a window of an automobile and a reception signal from the antenna conductor is sent to the receiver. Between the provided audio equipment and the power supply, between the low frequency amplification section of the receiver and the speaker, between the low frequency amplification section of the audio equipment and the speaker, the input of the low frequency amplification section of the receiver, and the audio Provided is a receiving system for an automobile, characterized in that a filter for attenuating a tuning frequency is connected to at least one selected from an input of a low frequency amplifying section of a device.

Further, according to the present invention, a glass plate of a rear window of an automobile is provided with an antenna conductor and an electrically heated defogger having a heater wire and a bus bar for feeding the heater wire, and the defogger is used as an antenna. In addition, the antenna conductor and the defogger are capacitively coupled to each other at a predetermined distance so that direct current is not transmitted and received between the antenna conductor and the defogger, but high-frequency current is transmitted and received. And a battery, and a bus bar on the other side and a ground are connected to a choke coil.

Further, the present invention provides the above-mentioned automobile receiving system, wherein the filter is a low-pass filter.

The present invention will be described in detail below with reference to the drawings.

In the present invention, a filter having a function of attenuating a desired reception frequency band or a desired broadcasting frequency band is used. Such a filter can be used as a filter of any specifications such as a low-pass filter, a band-pass filter, and a band elimination filter as long as it has a necessary function. Of these, the low pass filter is preferable. This is because not only the desired reception frequency band and the like, but also the harmonics of the tuning frequency that can be a noise component can be cut.

When a low-pass filter is used as the filter according to the present invention, it is necessary to use a filter having a function of attenuating substantially the lowest frequency or more such as a desired broadcast frequency band.

When a bandpass filter is used as the filter according to the present invention, a filter having a function of passing a frequency band other than the desired broadcast frequency band and attenuating the frequency band such as the desired broadcast frequency band is used. Need to use.

When a band elimination filter is used as the filter according to the present invention, it is necessary to use a filter having a function of attenuating a frequency band such as a desired broadcast frequency band.

Here, the band elimination filter means the highest frequency (1605 kHz for AM radio broadcasting) and the lowest frequency (500 kHz for AM radio broadcasting) of a desired broadcasting frequency band.
It means a filter that attenuates the frequency sandwiched by z).

FIG. 2 shows an example of the configuration of the low-pass filter. In FIG. 2, the coil 2 is used as the power source of the amplifier in the low frequency amplifier.
7 and capacitors 28 and 29 are connected. Usually, the coil 27 is 1 μH to 1 mH, and the capacitor 28 is 1 to 500.
For the μF and the capacitor 29, 0.001 to 0.1 μF is used. The capacitor 28 is mainly for low frequencies and medium and high frequencies, and the capacitor 29 is mainly for high frequencies.

When a filter that attenuates the tuning frequency is used as the filter according to the present invention, it is necessary to use a filter that has a function of changing the attenuation frequency of the filter. As means for matching the frequency with the tuning frequency, for example,
There are means such as sending a tuning frequency or a signal related to the tuning frequency from the receiver to the filter to control the attenuation frequency.

The filter for attenuating the tuning frequency may be a low pass filter, a band pass filter, a band elimination filter or the like, as long as it has a function of attenuating frequencies near the tuning frequency. Of these, the low pass filter is preferable. This is because not only the desired reception frequency band and the like, but also the harmonics of the tuning frequency that can be a noise component can be cut.

As for the attenuation characteristic of the filter according to the present invention, it is preferable that the attenuation is as large as possible, but normally, if the attenuation gain is larger than 2 to 3 dB, some effect can be expected and the attenuation gain is larger than 4 to 5 dB. Is preferable.

Further, regarding the place where the filter according to the present invention is connected, between the receiver and the power source, between the audio device and the power source when the audio device is provided separately from the receiver, the receiver is connected. Between the low frequency amplification section and the speaker or between the low frequency amplification section of the audio device and the speaker, it may be connected to any of the input of the low frequency amplification section of the receiver and the input of the low frequency amplification section of the audio device, It may be connected to one place (between one) between these, or may be connected to a plurality of places (between a plurality). In addition, it is more desirable for the noise reduction effect to be large when the filter is connected to all the locations between them.

When the filter is connected between the receiver and the power source or between the audio device and the power source, the connection point of the filter is the input end of the power source of the audio device or the like, the internal power line of the audio device or the like, Between the audio equipment and the power supply, such as the end of the power cable or the middle of the power supply, the output end of the power supply, the inside of the power supply, etc., any location may be used as long as the tuning frequency component leaks, only one location Instead, the filters may be connected to a plurality of places.

When the filter is connected between the low frequency amplification section of the receiver and the speaker or between the low frequency amplification section of the audio equipment and the speaker, the connection point of the filter is the low frequency amplification section of the audio equipment. Output terminal, speaker cable end or midway, speaker input terminal, audio equipment, etc., and any location as long as the tuning frequency component leaks between the speaker and only one location. Instead, the filters may be connected to a plurality of places.

The antenna conductor according to the present invention is usually manufactured by printing a glass plate of a window with a conductive metal-containing paste such as a conductive silver paste on the inside surface of the glass plate of the window and baking it. However, the present invention is not limited to this, and a conductor wire, a conductor foil, or the like may be provided on the glass plate of the window.

The receiver according to the present invention refers to a device that causes generation of a tuning frequency component, and corresponds to various receivers, radio receivers, televisions and the like. Further, the audio device according to the present invention includes a tape recorder, a cassette tape recorder,
A device such as a CD deck that drives a speaker to generate sound.

According to the present invention, the effect of the present invention is exerted particularly when the antenna conductor provided on the glass plate of the window of the automobile is close to the speaker, the speaker cable or the audio device and the power cable.

Generally, an antenna conductor is often provided on the glass plate of the rear window of an automobile, and a speaker is provided near the glass plate of the rear window. In such a case, it is provided on the glass plate of the automobile window. Since the antenna conductor and the speaker are close to each other, it becomes easy for the antenna conductor to receive the radio wave of the RF carrier component from the speaker cable or the like, and noise increases. In such a case, the effect of the present invention is particularly exerted.

An electrically heated defogger having a heater wire and a bus bar for feeding the heater wire is provided on the glass plate of the rear window of the automobile, and the defogger is used as an antenna. In this case, when the antenna conductor and the defogger are capacitively coupled in close proximity to each other at a predetermined interval so that direct current is not transmitted and received but high-frequency current is transmitted and received, between one bus bar and the battery. And it is necessary to connect a choke coil between the other bus bar and ground. This is because the defogger is insulated from the ground in the high frequency range by the choke coil.

[0032]

According to the present invention, even if the tuning frequency leaks from the power cable or the like to the input of the low frequency amplifier of the receiver and the tuning frequency is amplified and output from the low frequency amplifier of the receiver, the speaker cable The RF carrier component is attenuated due to the filter connected to, and the probability that a radio wave from a speaker cable, a power cable, or the like jumps out into the air is small, and noise is reduced.

[0033]

【Example】

(Embodiment 1) FIG. 1 is a configuration diagram showing Embodiment 1. In FIG. 1, 1 is an AM radio as a receiver, 2 is a low-pass filter consisting of a capacitor and a resistor, 3 is a speaker,
A battery 10 is a power source. Reference numeral 11 is a CD deck, and 22 is a low-pass filter including a coil. In the first embodiment, the low-pass filter 22 and the CD deck 1 are used.
1 was not set.

The above-mentioned devices and the like are installed inside the automobile. As for the glass antenna, an antenna conductor is provided on a glass plate of a rear window of an automobile, and a received signal from the antenna conductor is sent by a coaxial cable to an AM radio 1 provided near a driver's seat, and the AM radio 1 The low frequency amplifier of the AM radio 1 drives the speaker 3 provided near the glass plate of the rear window.

The antenna conductor provided on the glass plate of the rear window and the speaker 3 were separated by a minimum distance of about 400 mm.

In the first embodiment, the low-pass filter 2 is provided at the output end of the low frequency amplification section of the AM radio 1. The cutoff frequency of the low-pass filter 2 was 20 kHz.
The attenuation gain of the low-pass filter 2 at 526.5 kHz near the lower limit frequency of the AM radio broadcast frequency band (AM band) was about 28 dB.

An automobile receiving system similar to that of Example 1 was manufactured except that the low-pass filter 2 was not provided, and was used as Comparative Example 1. Comparing Example 1 with Comparative Example 1, in Example 1, A
The reception S / N ratio in the M band was improved by an average of about 5 dB as compared with Comparative Example 1.

(Embodiment 2) In Embodiment 2, the low-pass filter 22 and C shown in FIG.
D deck 11 is provided. Other configurations were the same as in the first embodiment. 526.5 kHz near the lower limit frequency of the AM band
The attenuation gain of the low-pass filter 22 at z is about 20.
It was dB.

A comparative example 2 was manufactured by manufacturing an automobile receiving system similar to that of the example 2 except that the low-pass filter 2 and the low-pass filter 22 were not provided. Comparing Example 2 with Comparative Example 2, in Example 2, the reception S / N ratio in the AM band was improved by an average of about 7 dB as compared with Comparative Example 2.

(Example 3) Instead of the low-pass filter 2, a band elimination filter that attenuates the tuning frequency was used. Regarding the tuning frequency attenuated by the band elimination filter, a direct current voltage proportional to the tuning frequency was sent from the AM radio 1 to the band elimination filter to control the frequency to be attenuated. The attenuation gain of the frequency to be attenuated by the band elimination filter was about 15 dB.

Other specifications were the same as those in the first embodiment. Comparing Example 3 with Comparative Example 1, in Example 3, the reception S / N ratio in the AM band is about 4 dB on average as compared with Comparative Example 1.
Improved.

[0042]

According to the present invention, even if the tuning frequency leaks from the power cable or the like to the input of the low frequency amplification section of the receiver and the tuning frequency is amplified and output from the low frequency amplification section of the receiver, the speaker cable or Because of the filter connected to the power cable or the like, the RF carrier component is attenuated, and there is little probability that the RF carrier component becomes a radio wave from the speaker cable, the power cable or the like and jumps out into the air. Therefore, there is little probability that the antenna conductor provided on the glass plate of the window of the automobile will receive the RF carrier component converted into the radio wave, and the noise will be reduced and the S /
The N ratio is improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment.

FIG. 2 is a circuit diagram showing an example of the configuration of a low-pass filter.

[Explanation of symbols]

 1: AM radio which is a receiver 2: Low-pass filter 3: Speaker 10: Battery which is a power source 11: CD deck 22: Low-pass filter consisting of a coil

Claims (6)

[Claims] 1. A vehicle reception system in which an antenna conductor is provided on a glass plate of a window of an automobile and a reception signal from the antenna conductor is sent to a receiver, wherein a low-frequency amplifier section of the receiver is provided between the receiver and a power supply. A filter for attenuating a desired reception frequency band or a desired broadcast frequency band is connected to at least one selected from a speaker and an input of a low-frequency amplification unit of a receiver system. 2. A vehicle reception system in which an antenna conductor is provided on a glass plate of a window of an automobile and a reception signal from the antenna conductor is sent to the receiver, and a voice is provided between the receiver and a power source and separately from the receiver. Between the device and the power supply, between the low frequency amplification unit of the receiver and the speaker, between the low frequency amplification unit of the audio device and the speaker, the input of the low frequency amplification unit of the receiver, and
A vehicle receiving system characterized in that a filter for attenuating a desired reception frequency band or a desired broadcasting frequency band is connected to at least one selected from an input of a low frequency amplification section of an audio device. 3. A vehicle receiving system in which an antenna conductor is provided on a glass plate of a window of an automobile and sends a reception signal from the antenna conductor to a receiver, in a low frequency amplifying section of the receiver between the receiver and a power source. A receiving system for an automobile, characterized in that a filter for attenuating a tuning frequency is connected to one or more selected from a speaker and an input of a low frequency amplifier of a receiver. 4. An audio reception system for an automobile, wherein an antenna conductor is provided on a glass plate of a window of an automobile and a reception signal from the antenna conductor is sent to the receiver, which is provided between the receiver and the power supply and separately from the receiver. Between the device and the power supply, between the low frequency amplification unit of the receiver and the speaker, between the low frequency amplification unit of the audio device and the speaker, the input of the low frequency amplification unit of the receiver, and
An automobile receiving system, characterized in that a filter for attenuating a tuning frequency is connected to at least one selected from an input of a low frequency amplifier of an audio device. 5. An antenna conductor is provided on a glass plate of a rear window of an automobile, and an electric heating type defogger having a heater wire and a bus bar for feeding the heater wire is provided, and the antenna conductor is used for the defogger as an antenna. DC current is not transmitted and received between the defogger and the defogger, so that high-frequency current is transmitted and received, the antenna conductor and the defogger are capacitively coupled close to each other at a predetermined interval, and one of the bus bar and the battery is connected. 5. The vehicle receiving system according to claim 1, further comprising a choke coil connected between the bus bar and the other bus bar and the ground. 6. The vehicle receiving system according to claim 1, wherein the filter is a low-pass filter.