KR20000011165U - External circuit box to convert mono audio signal to stereo audio signal - Google Patents

Abstract

The present invention provides a tuner unit for outputting a broadcast signal received by tuning to a channel corresponding to a user's request, and a voice signal processor for processing and outputting a voice signal from among the broadcast signals applied separately from the tuner unit and outputting the same. An external circuit box connected to a mono television including an audio signal output terminal for transmitting an output signal from an audio signal processing unit to an external device, wherein the FM signal output from the audio signal processing unit of the mono television is transmitted through the audio signal output terminal. It receives and amplifies L + R signal, which is the first voice signal of 4.5MHz, and LR signal, which is the second voice signal of 4.7242MHz, and adds L + R and LR signals in phase, or adds L + R and LR signals in phase. A stereo processor which subtracts the signal out of phase and separates the L and R signals and outputs them as left and right signals; A voice signal amplification unit further amplifies and outputs the output L and R signals, and replaces the current mono television with an expensive new stereo television by receiving the mono audio signal output from the mono television and converting the signal to stereo mode. There is no need to do it.

Description

External circuit box for converting mono voice signal into stereo voice signal

The present invention relates to an external circuit box for converting a mono audio signal into a stereo audio signal, and more particularly, to an external circuit box having a stereo processor for receiving a mono audio signal output from a mono television and converting the signal into a stereo mode. .

In general, a mono television is a television which does not have stereo processing capability and thus always outputs audio only in a mono mode, whether the received broadcast signal is a stereo signal or a mono signal.

FIG. 1 is a block diagram of such a typical mono television, which includes a key input unit 10, a microcomputer 20, a tuner unit 30, a video signal processor 40, a monitor 50, an audio signal processor 60, and a speaker. And 70.

In this configuration, the key input unit 10 is an input means for performing the operation of the television, and has a plurality of keys including a channel switching key, etc., and outputs a key signal corresponding to a user's key operation. For the convenience of the user, the above-mentioned key signal is transmitted on an infrared carrier using a remote controller capable of remote input.

In addition, the microcomputer 20 generates a tuning signal for tuning a channel for controlling the overall operation of the television, a text control signal for displaying text information on a screen, and the tuner unit 30 generates the microcomputer 20. Tunes to the channel corresponding to the tune signal from the "

In addition, the video signal processing unit 40 processes the video signal among the broadcast signals separated and applied from the tuner unit 30 as a displayable signal and outputs it to the monitor 50, and the audio signal processing unit 60 is the tuner unit. The audio signal is separated from the broadcast signal 30 and is processed as an output signal and output to the speaker 70.

However, such a mono television outputs a voice signal only in a mono mode as it is known, so even when broadcasting a voice signal such as a music broadcast, only a mono should be listened to, so there is no stereoscopic and monotonous high-end television capable of stereo stereo. There was a problem that the burden on property, such as replacement.

Accordingly, an object of the present invention for solving the problems of the prior art as described above is to provide an external circuit box having a stereo processor that receives a mono audio signal output from a mono television and converts it into a stereo mode.

1 is a block diagram showing a typical mono television in the prior art;

2 is a block diagram showing an external circuit box for converting a mono voice signal into a stereo voice signal according to a preferred embodiment of the present invention;

3 is a block diagram showing a stereo processor used in the present invention.

<Explanation of symbols for the main parts of the drawings>

10: key input unit 20: microcomputer

30: tuner 40: video signal processing unit

50: monitor 60, 110, 160: audio signal processing unit

70: Speaker 120, 170: Audio signal output terminal

130: stereo processor 140: voice signal amplifier

150: power supply 210: 4.5 MHz filter

220: 4.72MHz filter 230: first voice demodulation unit

240: second speech demodulation unit 250, 260: amplification unit

270: wagon circuit

A feature of the circuit box of the present invention for achieving the above object is a tuner unit for outputting a broadcast signal received by tuning to a channel corresponding to a user's request, and outputs a voice signal of the broadcast signal applied separately from the tuner unit An external circuit box connected to a mono television comprising a voice signal processor for processing and outputting a signal as possible, and a voice signal output terminal for outputting an output signal from the voice signal processor to the outside. The FM signal outputted from the audio signal output terminal is input to extract and amplify the L + R signal, which is the first voice signal of 4.5 MHz, and the LR signal, which is the second voice signal of 4.7242 MHz, and amplify the L + R signal and the LR. Adds the signal in phase or subtracts the L + R and LR signals out of phase to separate the L and R signals, thus allowing left and right signals A stereo processor for document output, to contain voice signal amplifying section for further amplifying outputs the L signal and the R signal output from the stereo processor.

The above object and various advantages of the present invention will become more apparent from the preferred embodiments of the present invention described below with reference to the accompanying drawings by those skilled in the art.

Hereinafter, a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

First, before describing the circuit box of the present invention, a brief description of the operation of a television having a stereo processing function is as follows.

Such a television includes a stereo function and a control means for selecting the same, thereby detecting an audio mode from a received broadcast signal and automatically switching to a stereo mode if the audio mode of the received broadcast signal is a stereo mode. If is a mono mode is provided with an automatic audio mode function to automatically switch to the mono mode so that the user can listen conveniently, and also has the function to switch to the forced mono mode for all channels to listen.

On the other hand, in such a television, the user can reset the audio mode according to the key operation, and when the reception sensitivity decreases during the stereo mode, the user can forcibly switch to the mono mode by the key operation to increase the audio sensitivity and listen. When the channel is switched, it switches back to the automatic audio mode. That is, the above-described conventional audio mode control method is basically equipped with stereo processing so that the stereo mode and the mono mode can be selected and listened to as necessary.

Accordingly, the present invention relates to an external circuit box connected to a mono television in order to implement the functions of the above-described stereo television in a mono television, and FIG. 2 converts a mono audio signal into a stereo audio signal according to a preferred embodiment of the present invention. An external circuit box is shown.

The external circuit box of the present invention includes a stereo processor 130 and an audio signal amplifying unit 140, and outputs an FM signal output from the audio signal processing unit 110 or 160 of a mono television or a mono VCR to an audio signal output terminal 120 or A device which receives the input through the 170 and converts the FM signal into a stereo voice signal and amplifies the result more and outputs it to the speaker, receives a power separate from the mono television or the mono VCR from the power supply unit 150.

Here, the audio signal processing unit 110 or 160 of the mono television or the mono VCR processes the audio signal among the broadcast signals separated and applied from the tuner unit as a signal capable of outputting and outputs the signal in the mono mode through the speaker.

The stereo processor 130 receives the FM signal output from the voice signal processor through the voice signal output terminal, extracts and amplifies the first and second voice signals, and as shown in FIG. 210, the 4.72MHz filter 220, the first and second voice demodulator 230 and 240, the amplifier 250 and 260 and the difference circuit 270 is generally composed.

The 4.5MHz filter and the 4.72MHz filter 210 and 220 receive the FM signal from the audio signal output terminal and pass the first 4.5MHz voice signal and the 4.7242MHz second voice signal, respectively. Here, the 4.5 MHz FM signal, which is the first voice signal, contains an L + R (combined left and right signal) signal, and the 4.7242 MHz FM signal, which is the second voice signal, contains an L-R signal. For reference, when performing two voice broadcasts, the first voice signal may include Korean and the second voice signal may include a foreign language.

In addition, the first and second voice demodulators 230 and 240 demodulate the 4.5 MHz and 4.72 MHz FM signals and convert them into human-readable speech signals, that is, low frequencies of 50 to 15000 kHz. 250 and 260 amplify the audio signal of 50 to 15000 Hz.

The circuit 270 combines (adds) the L + R signal, which is the first voice signal, and the LR signal, which is the second voice signal, in phase, or synthesizes (subtracts) the L + R signal and the LR signal, in phase, to L. Separate the signal from the R signal. This is expressed as follows.

(L + R) + (L-R) = 2L (left signal obtained)

(L + R)-(L-R) = 2R (right signal obtained)

In general, a processor having a stereo function also shares two voice broadcasting functions, but the description thereof is omitted here because it is based on stereo broadcasting.

Finally, the voice signal amplification unit 140 receives the left signal and the right signal output from the stereo processor 130 and amplifies the sound signal to each speaker to listen to the stereo sound according to the taste of the individual. Play a role.

Now, the operation of the external circuit box having the above-described configuration will be described in detail.

First, a broadcast signal transmitted from a television station, that is, a composite signal in which a video signal, a first audio signal, and a second audio signal are mixed, is received through an antenna, tuned by a tuner in response to a user's request, and then subjected to various processes. It is output through the monitor and speakers. In this process, the FM signal in which the first and second audio signals are mixed is input to the stereo processor of the circuit box through the audio signal processing unit and the audio signal output terminal of the mono television to be stereo processed.

That is, the FM signal is inputted to the 4.5 MHz filter and the 4.72 MHz filter of the stereo processor and filtered through the L + R signal, which is the first voice signal of 4.5 MHz, and the LR signal, which is the second voice signal of 4.7242 MHz, respectively. And a low frequency of 50 to 15000 kHz, which is a human-readable audio signal by the second voice demodulator.

Then, each signal converted to low frequency is amplified by the amplification units, and then the first and second voice signals are reversed in phase with each other in the difference circuit to obtain an L signal as a left signal and an R signal as a right signal. Synthesize or add and subtract in phase. The left and right signals obtained as described above are input to the voice signal amplifier and further amplified by a voice signal of a desired level and output to the left and right speakers, respectively.

As described above, the present invention has been described with reference to preferred embodiments, but the present invention is not limited thereto, and the present invention may be embodied in various forms by adding various limitations or additions without departing from the technical spirit of the present invention. It is apparent to those skilled in the art to which the present invention belongs.

The circuit box according to the present invention, which operates as described above, receives the mono audio signal output from the mono television, converts the signal into stereo mode, and outputs the stereo audio, thereby eliminating the need to replace the current mono television with an expensive new stereo television. Have

Claims (1)

A tuner unit for outputting a broadcast signal received by tuning to a channel corresponding to a user's request, a voice signal processor for processing and outputting a voice signal from among broadcast signals separated and applied by the tuner unit as an outputable signal, and the voice signal processor In an external circuit box connected to a mono television comprising an audio signal output terminal for outputting an output signal from an external device: The FM signal output from the audio signal processing unit of the mono television is input through the audio signal output terminal and amplified by extracting the L + R signal, which is the first audio signal of 4.5 MHz, and the LR signal, which is the second audio signal of 4.7242 MHz. A stereo processor that separates the L and R signals by adding the L + R and LR signals in phase or subtracts the L + R and LR signals in phase and outputs the left and right signals as left and right signals, And an audio signal amplifier for amplifying and outputting the L and R signals output from the stereo processor.