KR0164559B1 - Multiple sound signal processing circuitry - Google Patents

Abstract

In color television and FM radio applying voice multiple system,

For voice multiplex signal processing, the IF IC for voice multiplex signal processing must be used, thereby reducing the compatibility of component devices.

Therefore, the intercarrier output demodulated by the SIF demodulation circuit 210 has a 5.5 MHz filter 130 and a 5.74 MHz filter 230 to apply an IF IC used for mono sound to a stereo television to perform a stereo function. After each pass through), the FM1 sound demodulator 120 and the FM2 sound demodulator 220 are configured to be demodulated as a sound signal and applied to the stereo decoder 70.

It is applied to mono television or stereo television by increasing the compatibility between components.

Description

Multiple voice signal processing circuit

1 is a conventional voice multiple signal processing circuit diagram.

2 is a voice signal processing circuit diagram according to the present invention.

* Explanation of symbols for main parts of the drawings

20: VIF SAW Filter 30: SIF SAW Filter

70: stereo decoder 100: VIF signal demodulation and FM1 demodulation unit

110: VIF demodulation circuit 120: FM1 sound demodulator

130: 5.5 MHz filter 200: SIF signal demodulation and FM2 demodulation unit

210: SIF demodulation circuit 220: FM2 sound demodulator

230: 5.74 MHz filter

In the present invention, video and audio equipment, such as color television and FM radio, to which a voice multiplexing system is applied, voice multi-voice capable of processing stereo sound using an IF IC developed for mono sound. It relates to a signal processing circuit.

The conventional voice multiplex signal processing circuit is used as shown in FIG.

A preamplifier 10 that amplifies the IF signal forces tuned by the tuner, and a VIF SAW filter 20 and SIF, which are separately installed and separated into an image intermediate frequency (VIF) and an audio intermediate frequency (SIF). SAW filter 30,

A VIF demodulator 40 for demodulating the VIF signal passing through the VIF SAW filter 20 and applying the composite video signal to a video process at a rear end thereof;

A SIF demodulator for demodulating the SIF signal passing through the SIF SAW filter 30 and outputting it to the filter unit 60 as an intercarrier signal and outputting a sound signal applied from the filter unit 60 to the stereo decoder 70 ( 50).

Here, the configuration of the SIF demodulator 50 and the filter unit 60 is essential for processing the voice multiple signals separated by the SIF SAW filter 30.

A stereo decoder 70 for processing the sound signal demodulated by the SIF demodulator 50 as a stereo or voice multiplex signal should be configured.

The SIF demodulation unit 50 and the filter unit 60 must constitute a separate SIF signal processing circuit essentially for a voice multiple system configuration, which is completely separate from the VIF signal processing circuit.

In other words, the SIF demodulation unit 50 and the filter unit 60 must be configured completely separate from the VIF signal in order to configure the voice multiple system. Therefore, the IF IC developed for mono sound cannot be used, and the high cost developed for the voice multiple system is required. IF IC must be used.

This in turn reduced the compatibility of the products as a whole and resulted in an increase in manufacturing costs.

Therefore, in view of the above problems, the present invention is to apply the IF IC, which is used for mono sound, to a stereo television to perform a stereo function.

A filter for separating only the voice multiple signal band among the intercarrier outputs demodulated by the SIF demodulator

An FM sound demodulator for demodulating the signal separated by the filter;

And a stereo decoder which processes the sound signal of the FM sound demodulator.

Referring to the present invention in detail based on the accompanying drawings as follows.

2 is a voice signal processing circuit diagram according to the present invention.

The present invention provides a signal processing circuit for separating an IF signal tuned by the tuner 5 and amplified by the preamplifier 10 into a VIF signal and a SIF signal by the VIF SAW filter 20 and the SIF SAW filter 30.

A video signal demodulation and FM1 detector 100 for demodulating the VIF signal into a composite video signal and outputting a mono sound FM1 sound;

A sound signal demodulation and FM2 detector 200 for demodulating the SIF signal into an intercarrier signal and outputting an FM2 sound which is a stereo sound;

And a stereo decoder 70 for processing the sound of the video signal demodulation and the FM1 detector 100 and the sound of the sound signal demodulation and the FM2 detector 200.

Here, the video signal demodulation and FM1 detector 100 includes a VIF demodulation circuit 110 for demodulating the VIF signal into a composite video signal.

A 5.5 MHz filter 130 for separating the FM1 signal among the intercarrier signals applied from the SIF demodulation circuit 210,

And an FM1 sound demodulator 120 for demodulating and outputting the intercarrier signal separated by the 5.5MHz filter 130 into a sound signal.

The sound signal demodulation and FM2 detector 200 includes an SIF demodulation circuit 210 for demodulating the SIF signal into an intercarrier signal,

A 5.74 MHz filter 230 for separating the FM2 signal among the intercarrier signals applied by the SIF demodulation circuit 210;

And an FM2 sound demodulator 220 for demodulating and outputting the intercarrier signal separated by the 5.74 MHz filter 230 into a sound signal.

The present invention thus constructed shows a signal processing procedure from a tuner section to a stereo decoder section in a color television for voice multiplexing.

First, among the RF signals inputted to the antenna AN, the IF signal of the desired broadcast signal is tuned by a tuning system known in the tuner 5.

The IF signal tuned by the tuner 5 is applied to the preamplifier 10 and amplified to compensate for several tens of dB forces to be attenuated in the next stage SAW filter.

The IF signal amplified by the preamplifier 10 is applied to the VIF SAW filter 20 and the sound signal is output as the attenuated VIF signal, while the video signal is applied to the SIF SAW filter 30 to the attenuated SIF signal. do.

That is, the VIF SAW filter 20 separates the picture signal, and the SIF SAW filter 30 separates the sound signal and outputs the sound signal.

The VIF signal passing through the VIF SAW filter 20 is demodulated in the VIF demodulation circuit 110 of the video signal demodulation and FM1 detector 100 and output as a composite video signal and output from the VIF demodulation circuit 110. The composite video signal is signaled in a video process (not shown) and then displayed on the CRT.

The SIF signal passing through the SIF SAW filter 30 is demodulated by the SIF demodulation circuit 210 of the sound signal demodulation and FM2 detector 200 and output as an intercarrier signal.

The intercarrier output output from the SIF demodulation circuit 210 is applied to the FM1 sound demodulator 120 only with a 5.5 MHz signal through the 5.5 MHz filter 130, while the 5.74 MHz through the 5.74 MHz filter 230. Only the signal is applied to the FM2 sound demodulator 220.

Here, the FM1 sound demodulator 120 and the FM2 sound demodulator 220 demodulate and output the sound signal applied through the 5.5 MHz filter 130 and the 5.74 MHz filter 230, respectively.

The sound signal output from the FM1 sound demodulator 120 is an FM mono sound signal, which is applied to the stereo decoder 70 at the rear end and is output as an audio signal through a de-emphasis process.

The sound signal output from the FM2 sound demodulator 220 is applied to the stereo decoder 70 to demodulate 54.7 MHz and then separate into 117 MHz and 274 MHz, where 117 MHz is stereo broadcasting and 274 MHz It is judged that the bilingual broadcasting is performed, and after switching the system according to the broadcasting method, it is output as an audio signal.

The audio signal output from the stereo decoder 70 is applied to an audio process (not shown), is adjusted through volume, treble, balance, bass, etc., and then amplified by the amplifier and output to the speaker.

Therefore, the present invention can be used for mono sound by applying an IF IC composed of VIF demodulation circuit 110 and FM1 sound demodulator 120 to a stereo television to perform a stereo function.

On the other hand, when the present invention is applied to a mono television rather than a stereo television, the FM1 sound demodulation is not required without configuring the SIF SAW filter 30, the SIF demodulation circuit 210, the 5.74 MHz filter 230, and the stereo decoder 70. Since the grandfather 120 demodulates and outputs the mono sound, it is possible to construct the mono television at low cost.

As described above, in the present invention, in color television using a voice multiple system, the IF IC used for mono sound can be applied as it is, thereby increasing component compatibility between products and reducing manufacturing costs.

Claims (3)

A signal processing circuit for separating the IF signal tuned by the tuner 5 and amplified by the preamplifier 10 into a VIF signal and a SIF signal by the VIF SAW filter 20 and the SIF SAW filter 30. A video signal demodulation and FM1 detection unit 100 for demodulating a composite video signal and outputting a mono sound FM1 sound, and a sound signal demodulation and FM2 detection for demodulating the SIF signal into an intercarrier signal and outputting a stereo sound FM2 sound. And a stereo decoder 70 for processing the sound of the video signal demodulation and FM1 detector 100 and the sound of the FM signal detector 200 and the sound of the FM2 detector 200. Voice signal processing circuit. The video signal demodulation and FM1 detection unit 100 of claim 1, wherein the video signal demodulation and the FM1 detection unit 100 demodulates the VIF signal into a complex video signal. And a FM1 sound demodulator 120 for demodulating and outputting the intercarrier signal separated by the 5.5MHz filter 130 into a sound signal. Voice signal processing circuit. The SIF demodulation circuit 210 of claim 1, wherein the sound signal demodulation and FM2 detection unit 200 demodulates the SIF signal into an intercarrier signal, and FM2 of the intercarrier signals applied from the SIF demodulation circuit 210. A multiple voice, characterized in that it consists of a 5.74MHz filter 230 for separating the signal, and an FM2 sound demodulator 220 for demodulating and outputting the intercarrier signal separated by the 5.74MHz filter 230 into a sound signal. Voice signal processing circuit.