KR19990035192A - Noise Reduction Device for Radio Reception System - Google Patents

Abstract

The noise canceling device of the radio receiving system removes the noise component applied when the radio broadcasting signal is received so that only the correct radio broadcasting signal can be heard. The filter circuit (low pass) is provided at the rear of the first filtering unit (band pass filter). Filter and high pass filter), and the operation of this circuit is connected to an external switch, i.e., externally mounted first and second switching units, so that white noise may be increased or hum noise may be generated when a radio broadcast signal is received. When the user operates the first and second switching units to drive the filter circuit in the circuit to remove and output the noise components, the user can only hear the correct radio broadcast signal from which the noise components have been removed.

Description

Noise Reduction Device for Radio Reception System

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio reception system, and more particularly, to a noise canceling device of a radio reception system.

The radio broadcast reception system is a device that allows a consumer to listen to a radio broadcast audio signal through a speaker by receiving a radio broadcast signal transmitted from a radio station.

Hereinafter, signal processing of a radio broadcasting reception system according to the prior art will be described with reference to FIG. 1.

1 is a block diagram illustrating a radio broadcast receiving system according to the prior art. Referring to FIG. 1, a block diagram illustrating a radio broadcasting reception system includes a receiver 10 and a receiver 10 for receiving a radio broadcast audio signal transmitted from a radio station. Band pass filtering of the radio broadcast audio signal received in the band (Band Pass Filtering), the intermediate frequency generator 12 for generating an intermediate frequency of the frequency for the radio broadcast signal, and the filtering unit 11 A mixing unit 13 for mixing and outputting the filtered frequency signal and the intermediate frequency signal generated by the intermediate frequency generating unit 12, and an amplifying unit for amplifying a predetermined level of the mixed signal output from the mixing unit 130 ( 14) and a speaker 15 for finally outputting the amplified signal output from the amplifying unit 14.

Here, the intermediate frequency generated by the intermediate frequency generator 12 is a frequency obtained by mixing a signal received from a super heterodyne receiver (not shown) with a signal of a local oscillator (not shown), and amplified by lowering the received frequency. It is easy to do. This intermediate frequency is usually 455 KHz for radio receivers and 10.7 MHz for FM receivers. In addition, the receiver 10 is an antenna for receiving a radio broadcast signal.

In addition, the first filtering unit 11 is a band pass filter, and passes only the AC signal of a given upper and lower cutoff frequency through a frequency signal for a radio broadcast receiving signal applied through the receiving unit 10. All other AC frequencies are attenuated and applied to the mixing section 13.

Let us look at the operation of the radio broadcast receiving system according to the prior art having such a configuration.

First, a radio broadcast signal transmitted from a radio station is received by the receiver 10, that is, through an antenna.

In this way, the corresponding frequency for the received radio broadcast signal is band-pass filtered as described above by the first filtering unit 11 and output to the mixing unit 13. At this time, the intermediate frequency generator 12 generates an intermediate frequency only to facilitate amplification in the amplifier 14 at a frequency having a lower frequency band than the frequency filtered by the first filtering unit 11. Is applied.

The frequency signal generated by the intermediate frequency generator 12 is mixed with the intermediate frequency applied by the first filtering unit 11 and the frequency signal filtered by the mixing unit 13 to amplify the frequency signal for the mixed radio broadcast signal ( 14)

The amplifying unit 14 amplifies the frequency signal mixed and output from the mixing unit 13 to a predetermined level which can be output to the user through the speaker 15, and outputs the same to the speaker 15. It is output through the speaker 15.

However, in the conventional radio broadcasting reception system, a noise component is mixed and applied through an antenna as described above. When the noise component is applied, the amplification unit amplifies the noise component along with the radio broadcast signal. Because it is output through the user there is a problem that can not hear the right radio broadcast signal. That is, the noise component may generate white noise when a corresponding frequency of an applied radio broadcast signal is a high frequency, and in the case of a low frequency, a hum component is mixed and applied. Therefore, when the user hears the radio broadcast signal, the user cannot hear the correct radio broadcast signal due to the noise component.

Accordingly, the present invention has been made to solve the above-mentioned problems according to the prior art, the object of the present invention is to remove the noise component applied when receiving a radio broadcast signal radio to listen to only the correct radio broadcast signal The present invention provides a noise canceling device for a receiving system.

1 is a block diagram showing a radio broadcasting reception system according to the prior art

2 is a block diagram showing an apparatus for removing noise in a radio reception system according to the present invention.

FIG. 3 is a view illustrating shapes of a first switching unit and a second switching unit illustrated in FIG. 2.

♣ Explanation of symbols for main part of drawing ♣

20: receiver 21, 25, 26: filter

22: intermediate frequency generator 23, 24: switching unit

27: mixing section 28: amplifying section

29: speaker

In order to achieve the above object, there is provided a noise canceling device of a radio reception system according to the present invention, in a radio broadcast reception system having an antenna, an intermediate frequency generator, and a speaker. A plurality of switching units for providing a selection signal for removing noise components in the high frequency band and the low frequency band, respectively, when it is applied; A filtering unit filtering the radio broadcast signals received according to the selection signals of the plurality of switching units to remove noise components; A mixing unit which mixes the radio broadcasting signal filtered by the filtering unit and the noise component is removed with the intermediate frequency generated by the intermediate frequency generating unit; And an amplifier for amplifying and outputting the radio broadcast signal mixed by the mixer.

As another feature of the present invention, the plurality of switching units includes: a first switching unit for switching the radio broadcasting signal to be output to the filtering unit in order to remove a noise component generated in a low frequency band when the radio broadcasting signal is received; And a second switching unit for switching the output of the received radio broadcast signal to the filtering unit in order to remove the noise component of the low frequency, wherein the filtering unit receives the radio broadcast signal received according to the selection of the switching unit. A first filtering unit for filtering a low frequency band of the signal to remove noise components generated in the low frequency band; And a second filtering unit filtering the high frequency band of the radio broadcast signal received according to the selection of the switching unit to remove noise components generated in the high frequency band.

And, the switching unit is a rotary switch, it is characterized in that it is mounted on the outside of the radio system so that the user can directly select arbitrarily.

Hereinafter, an embodiment of an apparatus for removing noise of a radio broadcasting reception system according to the present invention will be described with reference to the accompanying drawings.

FIG. 2 is a block diagram illustrating an apparatus for removing noise of a radio broadcasting reception system according to an embodiment of the present invention, and FIG. 3 is a view showing the first and second switching units shown in FIG.

In the description of the configuration with reference to Figure 2 with respect to the same components that are repeated with the prior art shown in Figure 1 will be omitted and described. In the configuration, the first and second switching units connected to an output terminal of the first filtering unit 21 to provide a switching signal so as to filter out a noise component of a high frequency or a low frequency when a radio broadcast signal is received ( 23 and 24 and the low-pass or low-pass filtering of the band-pass filtered radio broadcast signal by the first filtering unit 21 according to the selective switching signals of the first and second switching units 23 and 24 selectively. Second and third filtering units 25 and 26 output to the mixing unit 27 are further configured.

Here, the first and second switching units 23 and 24 are rotary switches as shown in FIG. 3 and are mounted outside the radio system so that the user can directly select them arbitrarily. The second filtering unit 25 is a low pass filter for filtering only the low frequency band, and the third filtering unit 26 is a high pass filter for filtering only the high frequency band. do.

Let's look at the operation of the noise canceling apparatus of the radio broadcasting receiving system according to the present invention having such a configuration.

First, a radio broadcast signal transmitted from a radio station is received by the receiver 20, that is, through an antenna.

In this way, the corresponding frequency for the received radio broadcast signal is band-pass filtered as described above by the first filtering unit 21 and output to the mixing unit 27. At this time, the intermediate frequency generator 22 generates an intermediate frequency to easily amplify the amplifier 28 to a frequency having a lower frequency band than the frequency filtered by the first filtering unit 21 to generate the mixing unit 27. Is applied.

The intermediate frequency generated by the intermediate frequency generator 22 is mixed with the frequency signal filtered by the first filtering unit 21 in the mixing unit 27 to amplify the frequency signal for the mixed radio broadcast signal ( 28).

The amplifying unit 28 amplifies the frequency signal mixed and output by the mixing unit 27 to a predetermined level that can be output to the user through the speaker 29 and outputs the same to the speaker 29. It is output through the speaker 29.

In this way, when a noise component is applied while receiving a radio broadcast signal and outputting it through the speaker 29, and the user is disturbed when listening to the radio broadcast, the user switches the first switching unit 23 and the second switching unit 24, respectively. Switch to terminal b.

When the switching is performed in this way, the band pass filtered radio broadcast frequency signal is not directly applied to the mixing unit 27, but through the second filtering unit 25 and the third filtering unit 26, respectively. The low pass filtering and the high pass filtering remove the respective noise components (white noise and hum components) in the low band and the band and apply them to the mixing unit 27.

The radio broadcasting signal from which the noise component is removed by the mixing unit 27 is mixed with the intermediate frequency generated by the intermediate frequency generating unit 22 and amplified by the amplifying unit 28 and finally through the speaker 29. Is output.

If the user hears the radio broadcast through the speaker 29, the white noise generated in the high frequency band, that is, the buzzing sound is heard, the second switching unit 24 is switched to a terminal, that is, shown in FIG. When the second switching unit 24 is switched to the 8 KHz stage, only the high frequency band frequency signal of the radio broadcasting signals filtered by the first filtering unit 21 is filtered and other frequency signals and noise components are filtered and mixed unit ( 27). At this time, the terminal of the first switching unit 23 is selected to the b terminal. Here, since the operation | movement after the mixing part 27 is the same as that demonstrated above, the description is abbreviate | omitted.

On the other hand, when the user hears the radio broadcast through the speaker 29, when the noise of the hum component generated in the low frequency band is generated, the first switching unit 23 is switched to the terminal a, that is, the third shown in FIG. When the first switching unit 23 is switched to the 30 Hz stage, the first filtering unit 21 filters only the low frequency band frequency signal and filters other frequency signals and noise components, thereby mixing the mixing unit 27. Will output Here, 30 Hz and 8 KHz shown in the first and second switching units 23 and 24 shown in FIG. 3 are arbitrarily set values.

As a result, the present invention constitutes a filter circuit at the rear end of the first filtering unit 21 in the circuit configuration shown in FIG. 1 to control the operation of the circuit, that is, externally mounted first and second switching units 23, 24), when the white noise is increased when the radio broadcast signal is received or the noise component of the hum component is generated, the user operates the first and second switching units 23 and 24 shown in FIG. The noise components generated by driving (25, 26) are removed and output.

As described above, the apparatus for removing noise of a radio broadcasting reception system according to the present invention comprises a filter circuit (a low pass filter and a high pass filter) at a rear end of a first filtering unit (band pass filter) in the circuit configuration shown in FIG. By connecting the operation of the circuit with an external switch, that is, the externally mounted first and second switching units, if the white noise increases or the hum component noise component is generated when the radio broadcast signal is received, the user is shown in FIG. The first and second switching units are operated to drive the filter circuit in the circuit to remove and output noise components. Therefore, the user can hear only the correct radio broadcast signal from which the noise component is removed through the speaker.

Claims (1)

In a radio broadcasting reception system having an antenna, an intermediate frequency generator and a speaker, A plurality of switching units for providing a selection signal for removing noise components of a high frequency band and a low frequency band when a noise component is applied to a radio broadcast signal received through an antenna; A first filtering unit filtering a low frequency band of a radio broadcast signal received according to the selection of the switching unit to remove noise components generated in the low frequency band; A second filtering unit filtering the high frequency band of the radio broadcast signal received according to the selection of the switching unit to remove noise components generated in the high frequency band; A mixing unit for mixing the radio broadcasting signal filtered by the first and second filtering units and removing the noise component with an intermediate frequency generated by the intermediate frequency generating unit; And amplifying unit configured to amplify the radio broadcasting signal mixed by the mixing unit and output the same through the speaker.