KR100210776B1 - Stereo-mode switching control apparatus for television set - Google Patents

Abstract

The present invention relates to a stereo mode switching control apparatus of a television, wherein the audio signal determines a stereo mode based on the level of the R channel voice and the L channel voice of the audio signal reproduced by the voice multiplexer 14. The stereo mode pilot signal detection result from the discrimination unit 20 and the pilot signal detection unit 18 and the stereo signal discrimination result from the stereo signal discrimination unit 20 are ANDed to control the display of the stereo mode. And a control unit 10 for setting a stereo mode for the voice multiplexer 14, wherein the stereo signal discrimination unit 20 is a first half-wave rectified R channel / L channel voice of the voice signal. And first and second integrators 20 for integrating the second half-wave rectifiers 202 and 206 and the half-wave rectified R channel / L channel voices of the corresponding first and second half-wave rectifiers 202 and 206 to a DC level. 4,208), the differential amplifier 210 differentially amplifies the DC levels of the R channel / L channel voices from the first and second integrators 204 and 208, and compares the differential amplifier amounts of the differential amplifier 210 with a reference voltage. The comparator 212 generates a stereo signal discrimination result.

Description

Stereo Mode Switching Control Unit of TV

The present invention relates to a stereo mode switching control apparatus of a television. More particularly, the amplification amount is obtained by differentially amplifying a DC level obtained by half-wave rectifying the level of an L channel signal and an R channel signal when the stereo mode is switched to an audio signal of a television. In the case of more than this predetermined amount, it is related with the stereo mode switching control apparatus of the television for enabling switching to a stereo mode.

At present, a TV that reproduces a video / audio signal constituting a broadcast program has evolved from a method of simply reproducing an audio signal and delivering it to a viewer, and various processing techniques have been introduced for the audio signal. In other words, in the present television, a multi-language audio signal can be selectively reproduced for the audio signal, a stereo mode for enhancing the realism, and a mono signal is transmitted to either of the R channel voice and the L channel voice. Is a state in which a surround mode function is added to delay the parallax parallax and process it as a pseudo stereo signal.

In addition, the broadcasting station adds a pilot signal that defines the mode of the audio signal (ie, multi-lingual audio / stereo mode / surround mode / mono mode) according to the type of broadcast program to a predetermined frequency band of the composite video signal. In the television equipped with the voice multiple processing function, the pilot signal is detected and displayed to the viewer by, for example, an LED display element or an OSD (On-screen Display) signal.

Therefore, when a command for designating the mode of the audio signal is input from the viewer in response to the mode guidance of the audio signal, the control means of the television controls the audio signal processing system according to the command so that the audio signal is in the mono mode, the stereo mode, It can be played in voice multi mode or surround mode.

However, when the surrounding noise component is mixed with the composite video signal by the video / audio signal of the broadcast program transmitted from the broadcasting station, the pilot signal included in the composite video signal is also greatly affected. In the case of detecting a pilot signal at, an error mode discrimination on the voice signal is performed by the mixed noise component, so that it is impossible to accurately set the mode of the voice signal.

That is, when the voice signal is set to the mono mode and the pilot signal is affected by the noise component during broadcasting, the noise component is misprocessed so that the display of the voice signal in the 'stereo' mode or the 'surround' mode is displayed. As a result, even if the viewer inputs a command for designating the mode of the audio signal, the possibility of a malfunction in which the audio signal is reproduced only in the mono mode is significantly increased. In addition, even in a broadcast program transmitted in stereo mode, a situation in which the display of the 'stereo' mode is flickered due to noise components may occur, causing confusion to the viewer.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances. The present invention has been made by detecting a pilot signal included in a composite video signal and performing a half-wave rectification of the R channel level and L channel level of the audio signal when switching to the stereo mode for the audio signal. It is an object of the present invention to provide a stereo mode switching control apparatus of a television for switching the stereo mode only when the level is differentially amplified and the amplification amount is a predetermined amount or more.

In order to achieve the above object, according to a preferred embodiment of the present invention, an IF processor which obtains an audio IF signal by performing intermediate frequency conversion processing on a composite video signal of a channel tuned by a tuner, and performing audio multiplex processing on the audio IF signal. A television comprising an audio multiple processing unit, an audio output unit for outputting the audio multiplexed audio signal, and a pilot signal detection unit for detecting a pilot signal for an audio signal reproduction mode included in the composite video signal. A stereo signal discrimination unit for discriminating the stereo mode of the audio signal based on the level of the R channel audio and the L channel audio of the audio signal reproduced by the multiple processing unit, a stereo mode pilot signal detection result from the pilot signal detection unit, and The stereo signal discrimination result from the stereo signal discriminating unit is ANDed to display the stereo mode. And a control unit for setting a stereo mode for the voice multiple processing unit, wherein the stereo signal discriminating unit first half-wave rectifies the R channel / L channel voice of the voice signal. And first and second integrators for integrating the half-wave rectified R-channel / L-channel voices of the corresponding first and second half-wave rectifiers to a DC level, and the R-channels / L from the first and second integrators. Provided is a stereo mode switching control apparatus for a television comprising a differential amplifier for differentially amplifying a DC level of a channel voice and a comparator for generating a stereo signal discrimination result by comparing the differential amplifier of the differential amplifier with a reference voltage.

According to the stereo mode switching control apparatus for a television according to the present invention having the above-described configuration, when the pilot signal is detected and the audio signal is switched to the stereo mode, the R channel level and the L channel level of the audio signal are half-wave rectified to adjust the DC level. The DC level of the R-channel and L-channel voices is differentially amplified, and switching to the stereo mode can be performed only when the differential amplification is a certain amount or more relative to the reference level.

1 is a block diagram of a stereo mode switching control apparatus for a television according to the present invention;

2 is a block diagram showing an example of the stereo signal discriminating unit shown in FIG. 1;

3 is a waveform diagram illustrating a processing procedure for an audio signal of an R channel / L channel executed in a stereo mode switching control apparatus of a television according to the present invention;

4 is a flowchart for explaining the operation of the stereo mode switching control apparatus of the television according to the present invention.

* Description of the symbols for the main parts of the drawings *

10: control unit, 12: IF processing unit,

14: audio multiple processing unit, 16: audio output unit,

18: pilot signal detection unit, 20: stereo signal discrimination unit,

202, 206: first and second half-wave rectifiers,

204, 208: first and second integrators, 210: differential amplifier,

212: comparator.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Fig. 1 is a block diagram showing a stereo mode switching control apparatus for a television according to the present invention. Reference numeral 10 denotes a pilot signal and a stereo discriminating signal while performing overall control of a corresponding television, for example, in response to a control signal from a remote controller. In response, the control unit controls the switching operation of the stereo mode of the audio signal, and 12 indicates that the composite video signal RF of a specific channel tuned by a tuner (not shown) under the control of the control unit 10 is an intermediate frequency. An IF processing unit which outputs a video IIIF signal PIF and an audio IF signal SIF by converting the frequency; In addition, 14 denotes a voice multiple processing unit for processing the audio IF signal in stereo mode under the control of the control unit 10 and outputting the audio signal of the R channel / L channel, and 16 denotes the voice multiple processing unit 14 processing. And an audio output unit for amplifying the audio signal of the R channel / L channel so as to be reproduced by the speaker device (not shown) of the R channel / L channel.

18 denotes a pilot signal detector that detects a pilot signal indicating a stereo mode from the composite video signal processed by the IF processor 12 and applies the detection result PD to the controller 10. Half-wave rectifies and integrates the stereo audio signal of the R-channel / L-channel processed by the voice multiplexer 14, differentially amplifies the DC level of the integration result, and compares the amplification amount with a predetermined reference level. It is determined whether the level of the R channel and the L channel of the signal are received in different stereo modes, and indicates a stereo signal discrimination unit for applying the determination result SD to the control unit 10, where 22 is the control unit 10. The mode display unit for visually displaying to the viewer that the voice signal is broadcast in the stereo mode as a result of the determination.

FIG. 2 is a block diagram showing an example of the stereo signal discrimination unit 20. The stereo signal discrimination unit 20 is a first half wave for half-wave rectifying the audio signal of the R channel processed by the audio multiplexer 14. A first integrator 204 for integrating and rectifying the DC signal of the R channel half-wave rectified by the first half-wave rectifier 202 and the L-channel processed by the voice multiplexer 14 A second half-wave rectifying unit 206 for half-wave rectifying the audio signal of the second signal; and a second integrating unit 204 for integrating and DC-leveling the audio signal of the L-channel half-wave rectified by the second half-wave rectifying unit 206. In addition, by differentially amplifying the DC level according to the integration result of the first and second integrators 204 and 208, the difference between the R channel and the L channel of the audio signal (ie, the state in which the audio signal is broadcast in the stereo mode) is obtained. The differential amplifier 210 to detect, the differential amplifier of the differential amplifier 210 to the stereo mode When the R channel / L channel level difference of the voice signal differentially amplified by the differential amplifier 210 is higher than the reference level Vref compared to the reference level Vref for the ring, the current voice signal is in stereo mode. Comparator 212 for generating a detection signal (SD) for the broadcast state to apply to the control unit 10 is configured.

Next, the operation of the stereo mode switching control apparatus of the television according to the present invention having the above-described configuration will be described in detail with reference to the waveform diagram of FIG. 3 and the flowchart of FIG. 4.

First, when a control signal for tuning a channel, for example, is input from the viewer to the controller 10, the controller 10 applies tuning data for a channel to be tuned to a tuner (not shown). Accordingly, the composite video signal RF of the channel tuned by the tuner is applied to the IF processor 12. Then, the IF processor 12 performs an intermediate frequency conversion process on the composite video signal RF to obtain an audio IF signal SIF, and the audio IF signal SIF is applied to the audio multiplexer 14 for reproduction. It is processed and output (Rout / Lout) to a speaker device (not shown) via the audio output unit 16 as an audio signal of the R channel / L channel.

In the meantime, the pilot signal detection unit 18 detects the audio signal reproduction mode (e.g., mono mode / stereo mode / surround mode / 2-language mode) from the composite video signal RF processed by the IF processing unit 12. (Step 300), if the filer signal indicates stereo mode as a result of the detection (i.e., 'YES' in step 302), the pilot signal detection unit 18 reads the high level stereo mode detection signal PD. The control unit 10 is applied.

In addition, the stereo signal discrimination unit 20 receives the R-channel audio and L-channel audio signals (refer to the waveforms of FIGS. 3 (a) and (a ')) which are reproduced and output by the audio multiplexer 14. When the first and second half-wave rectifiers 202 and 206 of the stereo discriminating unit 20 perform half-wave rectification (refer to the waveforms of FIGS. 3 (b) and (b '), respectively, in step 304). It is applied to the corresponding first and second integrators 204 and 208 at the later stages.

Accordingly, the first and second integrators 204 and 208 integrate the R-channel voice and the L-channel voice half-wave rectified by the corresponding first and second half-wave rectifiers 202 and 206 to DC level (Fig. 3 (c)). ), And the DC level of the R channel voice and the L channel voice is applied to the non-inverting terminal (+) and the inverting terminal (-) of the differential amplifier 210 of the rear stage and differentially amplified ( Step 306).

The differential amplification result of the DC level of the R channel voice and the L channel voice in the differential amplifier 210 is applied to the non-inverting terminal (+) of the comparator 212 at the rear end thereof, and the inverting terminal (−) of the comparator 212 is applied. Is compared with the reference voltage Vref set in step S308. As a result of the comparison, when the differential amplification level with respect to the DC level of the R channel voice and the L channel voice is larger than the reference voltage Vref (YES in step 310), the R channel voice and the L channel voice have a level difference. A high level stereo signal discrimination result (SD) is determined to be a stereo sound signal having a and is applied to the controller 10, while the differential amplification level with respect to the DC level of the R channel sound and the L channel sound is equal to the reference voltage. Vref) is small (NO in step 310), the R channel voice and the L channel voice are judged to be mono audio signals with a small level difference, and a low level discrimination result SD is transmitted to the controller 10. Is approved.

Therefore, the controller 10 performs AND processing the stereo pilot signal detection result PD from the pilot signal detection unit 18 and the stereo signal discrimination result SD from the stereo signal discrimination unit 20, for example, and performs the stereo processing. When the signal discrimination result SD is applied at a high level, it is determined that the audio signal included in the composite video signal is in stereo mode so that the 'stereo' mode is displayed by the mode display unit 22 and the stereo mode is displayed from the viewer. When a control signal for switching of is inputted, the voice multiplexer 14 controls to perform a stereo mode processing on the voice IF signal (step 312). On the other hand, if the low level discrimination result SD is applied from the stereo signal discriminating unit 20, it is determined that the audio signal included in the composite video signal is not in the stereo mode, and the flow proceeds to step 314 to enter the stereo mode. The switching is not executed (step 314).

On the other hand, in the above description, when the differential amplification amount of the R channel voice and the L channel voice is large with respect to the reference voltage Vref as described above, the stereo mode is displayed so that the viewer enters the stereo mode. When switching is input, the audio signal is controlled to be processed in the stereo mode. However, the present invention is not limited to such an example, but the pilot signal is detected in the stereo mode and the stereo signal discrimination unit 20 discriminates the high level stereo signal. When the result is applied, the control unit 10 may control the audio multiple processing unit 14 to automatically switch the audio signal reproduction mode to the stereo mode.

As described above, according to the stereo mode switching control apparatus of the television according to the present invention, the stereo mode is detected by the pilot signal included in the composite video signal and transmitted, and the R channel audio and the L channel audio by the stereo signal discrimination unit. When the differential amplification is greater than or equal to the reference voltage, it is possible to determine the stereo mode and to switch the mode manually or automatically. Therefore, the stereo mode setting is more accurate than when the stereo mode is displayed and set only by the pilot signal. It becomes possible.

Claims (2)

An IF processor 12 which obtains an audio IF signal by performing intermediate frequency conversion processing on the composite video signal of the channel selected by the tuner, an audio multiple processing unit 14 which performs audio multiplexing on the audio IF signal, and its audio multiplexing process. A television comprising an audio output unit 16 for outputting an audio signal and a pilot signal detection unit 18 for detecting a pilot signal for an audio signal reproduction mode included in the composite video signal, A stereo signal discriminating unit 20 for determining the stereo mode of the audio signal based on the R channel voice and the L channel voice levels of the voice signal reproduced by the voice multiple processor 14; The audio multiprocessor 14 controls the display of the stereo mode by AND-processing the stereo mode pilot signal detection result from the pilot signal detector 18 and the stereo signal discrimination result from the stereo signal discrimination unit 20. And a control unit (10) for setting a stereo mode for the television. 2. The stereo signal discrimination unit (20) according to claim 1, wherein the stereo signal discrimination unit (20) comprises first and second half wave rectifiers (202, 206) for half-wave rectifying the R channel / L channel voices of the voice signal, respectively. R and L channels from the first and second integrators 204 and 208 and the first and second integrators 204 and 208 for integrating the half wave rectified R channel and L channel voices of the half wave rectifiers 202 and 206 to a DC level. Stereo mode of a television comprising a differential amplifier 210 for differentially amplifying a DC level of a voice and a comparator 212 for generating a stereo signal discrimination result by comparing the differential amplification amount of the differential amplifier 210 with a reference voltage. Changeover control.

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