KR19990039735A - How to remove sound buzz on TV - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing sound buzz in a TV-C, which is capable of removing sound buzz, which is a low frequency noise component, from a TV-C. Determining whether the video power is turned off after the playback stops in the video playback mode, so that the sound buzz generated when the broadcast signal is viewed to the maximum, and is received by the tuner if the video power is not turned off. Determining whether a sound buzz is generated from a voice signal of an output broadcast signal, and performing automatic fine tuning until the sound buzz is removed to the maximum when a sound buzz is generated. Turn off the video after the video has stopped playing. The sound generated buzz without that will automatically remove as much as possible to provide users with high quality voice.

Description

How to remove sound buzz on TV

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing sound buzz in a TV-seal. In particular, the present invention relates to a method for removing sound buzz generated when a broadcast signal is received and viewed without turning off the video after the video is stopped. A method of removing sound buzz from a seed.

In general, a sound buzz is low frequency noise generated in an audio circuit of a television. The sound buzz is caused by a poor receiver, a poor automatic gain adjustment (AGC), or a high frequency image carrier interfering with a low frequency audio carrier.

On the other hand, TV-AL is a composite video device in which a television and a video cassette recorder are integrally formed, and each of them can play or record a video cassette tape through independent power on / off control, and can also receive a broadcast signal.

On the other hand, NTSC (National Television System Committe) FS (Frequency Syncronizing) method adopts AFT (Automatic Fine Tunning) voltage to tune the tuner of the receiver to the carrier frequency of each channel. have. That is, when the PLL data for tuning the frequency of each channel is stored in the memory of the microcomputer of the receiver and the user selects a predetermined channel by dial or the like, the microcomputer applies the PLL data of the selected channel to the tuner.

On the other hand, a phase lock loop is formed in the tuner to control the oscillation frequency of the voltage controlled oscillator according to the PLL data to receive the frequency signal of the channel selected by the user.

However, since the carrier frequency of the signal transmitted from the broadcasting station varies slightly depending on the region or environment, it is necessary to change the oscillation frequency of the voltage controlled oscillator in order to synchronize the carrier frequency with the tuner.

To this end, in the FS scheme, the AFT voltage is output according to the frequency of the IF signal output from the tuner, and the microcomputer is configured to finely change the PLL data according to the AFT voltage.

That is, in the FS method, the local oscillation frequency of the tuner is changed slightly by changing the PLL data output by the microcomputer, and the microcomputer is in an optimal tuning state in response to the output AFT voltage. The frequency of the intermediate frequency (IF) signal output from the tuner by changing the PLL data finely in predetermined step units so that the intermediate voltage rapidly changes within a window range (for example, 2.8 to 3.8 V) in a predetermined step unit is 45.75. MHz (for NTSC).

On the other hand, if the playback stops without turning off the video power when playing the video in the above-described TV with FS, the tuner is tuned to the recently tuned channel, and thus the received broadcast signal is processed and output to the monitor and the speaker. .

However, at this time, there is a problem that the above-mentioned sound buzz occurs to listen to the deteriorated voice.

Disclosure of the Invention An object of the present invention is to remove a sound buzz generated when watching a broadcast signal applied to a tuner without turning off the video after stopping video playback in a TV seed with an FS-type tuner. It is to provide a removal method.

According to the present invention, a method for removing sound buzz in a TV-C is a method of removing a sound buzz generated when a broadcast signal is applied to the tuner without turning off the video after the video is stopped. Determining whether the video power is turned off after the playback stops, determining whether a sound buzz is generated from a voice signal of a broadcast signal received and output by the tuner if the video power is not turned off, and the sound buzz And when performed, performing an automatic fine tuning (AFT) until the sound buzz is removed.

1 is a schematic block diagram of a TV seed employed in accordance with a preferred embodiment of the present invention.

Figure 2 is a flow chart illustrating a sound buzz control process in the TV seed according to a preferred embodiment of the present invention.

<Explanation of symbols for main parts of the drawings>

10: key input unit 20: microcomputer

30: tuner unit 40: video signal processing unit

50: monitor 60: audio signal processing unit

70: speaker 80: buzz detector

90: deck

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

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

FIG. 1 is a schematic block diagram of a TV signal employed according to a preferred embodiment of the present invention, and includes a key input unit 10, a microcomputer 20, a tuner unit 30, an image signal processing unit 40, and a monitor 50. ), A voice signal processor 60, a speaker 70, a buzz detector 80, and a deck unit 90.

In such a configuration, the key input unit 10 is provided with a plurality of keys for performing the operation of the TV seed and outputs a key signal corresponding to the user's key operation, it is usually predetermined by using a remote control that can be input from a remote location The key signal carried on the infrared carrier wave is transmitted / received and applied to the microcomputer 20.

The microcomputer 20 selectively controls the tuner 30, the image signal processor 40, the audio signal processor 60, and the deck unit 90 based on the key signal from the key input unit 10. If the video power is not turned off when playback stops, the tuner 30 is controlled until the buzz is removed based on a detection signal from the buzz detection unit 80 to perform automatic fine adjustment (AFT). do.

On the other hand, the tuner unit 30 outputs a broadcast signal received and tuned to the corresponding channel under the control of the microcomputer 20, and the automatic fine adjustment voltage corresponding to the tuning state based on the automatic fine tuning of the microcomputer 20. Is applied to the microcomputer 20.

In addition, the image signal processing unit 40 separates the image signal from the broadcast signal from the tuner unit 30 and processes the image signal into a displayable signal and outputs it to the monitor 50 or outputs the reproduced image signal from the deck unit 90. A signal that can be displayed is processed and output to the monitor 50.

The voice signal processor 60 separates the voice signal from the broadcast signal from the tuner 30 and processes the voice signal into a signal that can be output and outputs it to the speaker 70, or reproduced voice signal from the deck unit 90. Processes the signal as an output signal and outputs it to the speaker 60.

In addition, the buzz detector 80 detects whether the voice signal from the voice signal processor 60 has a buzz signal, which is a low frequency component, and applies the detection signal to the microcomputer 20 when the filtered low frequency signal is a buzz component. .

Meanwhile, the deck unit 90 reproduces the video signal and the audio signal recorded in the video cassette recorder under the control of the microcomputer 20, so that the video signal is the video signal processing unit 40, and the audio signal is the audio signal processing unit ( 60) respectively.

Next, a detailed description will be given with reference to a flowchart of FIG. 2 attached to a sound buzz removing process in a TV-C according to a preferred embodiment of the present invention including the above-described configuration unit.

First, the microcomputer 20 controls the deck unit 90 to perform video playback (step 200), and determines whether video playback is stopped based on a predetermined key signal from the key input unit 10 (step 202).

At this time, when the video playback is stopped, TV-R will control the tuner 30 to automatically receive the recently tuned channel and output the received broadcast signal.

Next, when the video reproduction is stopped, it is judged whether or not the video power is turned off based on the predetermined key signal from the key input section 10 (step 204).

On the other hand, if the video power is not turned off at this time, the above-described sound buzz is generated. Therefore, the microcomputer 20 determines whether the sound buzz is generated based on the detection signal from the buzz detector 80 (step 206).

At this time, when a sound buzz is generated, the microcomputer 20 controls the tuner unit 30 to maintain an optimal tuning state in which the sound buzz does not occur (step 208).

Then, the process returns to the above-described step 206 to determine whether the sound buzz continues to be generated, and the microcomputer 20 continues to the above-described step 206 until the sound buzz is removed to the maximum and performs automatic fine adjustment. Perform.

On the other hand, if it is determined in step 206 that the sound buzz has been removed to the maximum, the automatic fine tuning ends and the main routine ends.

On the other hand, it will be understood by those skilled in the art that various changes and modifications can be made without departing from the spirit of the present invention.

As described above, according to the present invention, when playing a video on TV, the effect of automatically removing the sound buzz that occurs when the video is not turned off after stopping the video playback to the maximum to allow a user to listen to a good voice. There is.

Claims (1)

As a method of removing the sound buzz generated when watching a broadcast signal applied to the tuner without turning off the video after stopping the video playback in the TV-C, Determining whether the video power is turned off after playback stops in the video playback mode; Determining whether a sound buzz is generated from an audio signal of a broadcast signal received and output by the tuner when the video power is not turned off; When the sound buzz occurs, performing automatic fine tuning until the sound buzz is removed as much as possible.