KR19990042401A - How to control vertical sync on television - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical synchronization control method in a television, which is capable of preventing the vertical synchronization collapse on the screen caused by distortion of the vertical synchronization when a weak signal is received in a television. If the received reception sensitivity is equal to or greater than the preset reference sensitivity, the vertical synchronization signal included in the broadcast signal is separated and deflected. If the detected reception sensitivity is lower than the reference sensitivity, the period of the vertical synchronization signal separated from the broadcast signal and applied is predetermined. Generates and deflects a pseudo vertical sync signal having an average cycle calculated by counting, storing, counting and storing the average cycle of the stored cycle repeatedly to prevent false detection of the vertical sync signal due to noise when the reception sensitivity is lowered in a television. To prevent the screen's vertical sync from collapsing It is.

Description

How to control vertical sync on television

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical synchronization control method in a television, and more particularly, to a vertical synchronization control method in a television so as to prevent on-screen vertical synchronization collapse caused by distortion of the vertical synchronization when receiving a weak signal in a television.

In general, a sync signal, i.e., a horizontal sync signal, in a typical National Television System Committe (NTSC) broadcast has 30 (frames) X 525 (number of scan lines) = 15750 pulses per second, that is, a frequency of 15.75KHz. The vertical sync signal has a frequency of 60 Hz.

In television, the above-described synchronization signal is separated from the received broadcast signal and used for deflection control of the monitor.

However, when the reception state of the broadcast signal is not good, noise is introduced into the sync signal included in the broadcast signal, particularly the vertical sync signal, so that the sync signal is not clear and the image is deteriorated by bouncing vertically on the screen. There was a problem.

SUMMARY OF THE INVENTION An object of the present invention is to solve the conventional problems as described above. When the sensitivity of a broadcast signal received from a television is not good, the average period is calculated by counting the period of the vertical synchronization signal of the received broadcast signal. The present invention provides a vertical synchronization control method in a television system capable of generating and deflecting a pseudo vertical synchronization signal having a calculated average period to prevent vertical synchronization from collapsing.

The vertical synchronization control method in a television according to the present invention is a method for processing vertical synchronization when a reception sensitivity is lowered in a television, comprising the steps of: detecting a reception sensitivity of a received broadcast signal; If the error is detected, separating and deflecting the vertical synchronizing signal included in the broadcast signal; and if the detected reception sensitivity is lower than the reference sensitivity, counting and storing the period of the vertical synchronizing signal separated and applied from the broadcast signal repeatedly for a predetermined number of times. And generating and deflecting a pseudo vertical synchronizing signal having an average period calculated by calculating an average period of the stored period.

Meanwhile, during period counting and calculation of the vertical synchronization signal, a pseudo vertical synchronization signal according to the standard specification of the broadcast signal is generated and deflected.

1 is a block diagram of a television employed in accordance with the present invention;

2 is a flowchart illustrating a vertical synchronization control process 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: synchronization separation unit

70: deflection processing unit

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.

1 is a block diagram of a television employed in accordance with the present invention, which includes a key input unit 10, a microcomputer 20, a tuner unit 30, a video signal processing unit 40, a monitor 50, and a synchronization separating unit 60. ), And a deflection processing unit 70.

In such a configuration, the key input unit 10 is provided with a plurality of keys for performing the operation of the television outputs a key signal corresponding to the user's key operation, typically using a remote control that can be input from a remote location A key signal corresponding to a key operation is loaded on a predetermined infrared signal and transmitted, the received infrared signal is received, detected, amplified, and waveform-formed to output the received key signal.

In addition, the microcomputer 20 controls the overall operation of the television by controlling the tuner 30 and the image signal processor 40 in response to the key signal from the key input unit 10, and the image signal processor 40 to be described later. If the reception sensitivity of the broadcast signal applied from the preset sensitivity is equal to or less than the preset reference sensitivity, the deflection processing unit 70 outputs a pseudo vertical synchronization signal of the broadcast standard, and at the same time, the vertical synchronization applied from the synchronization separation unit 60 through the A / D port. The period of the signal is counted a predetermined number of times to calculate an average period of the counted period, and a pseudo vertical synchronization signal having the calculated average period is generated and applied to the deflection processing unit 70.

Meanwhile, the tuner unit 30 outputs a broadcast signal received by being tuned to a channel corresponding to the control of the microcomputer 20.

In addition, the image signal processing unit 40 separates the image signal from the broadcast signal from the tuner unit 30, processes the image signal into a displayable signal, and applies the same to the monitor 50. 20).

Then, the monitor 50 synchronizes the video signal from the video signal processor 40 based on the deflection signal from the deflection processor 70 and displays it on the screen.

Meanwhile, the sync separator 60 separates the horizontal sync signal and the vertical sync signal from the broadcast signal applied from the tuner 30 and applies it to the deflection processor 70, and applies the vertical sync signal to the microcomputer 20. .

The deflection processing unit 70 applies a deflection signal for deflection to the monitor 50 based on the horizontal synchronization signal and the vertical synchronization signal from the synchronization separation unit 60 to adjust horizontal and vertical synchronization on the screen. When the vertical synchronization signal is applied from 20), a deflection signal is generated and applied to the monitor 50 based on the vertical synchronization signal from the microcomputer 20 instead of the vertical synchronization signal from the synchronization separation unit 60.

Next, a description will be given in detail with reference to the flowchart of FIG. 2, which attaches a vertical synchronization control process in a television according to a preferred embodiment of the present invention in a television including the above-mentioned component.

First, when a user selects a channel using a predetermined key of the key input unit 10, the microcomputer 20 controls the tuner unit 30 to tune to a channel corresponding to the key signal from the key input unit 10. .

Then, the tuner unit 30 broadcasts the received broadcast signal tuned to the channel corresponding to the control of the microcomputer 20.

Next, the video signal processor 40 separates the video signal from the broadcast signal applied from the tuner 30, processes the video signal into a displayable signal, and outputs the signal to the monitor 50.

In addition, the vertical synchronizing signal and the horizontal synchronizing signal separated by the synchronizing separator 60 are processed as a deflection signal by the deflection processing unit 70 and applied to the monitor 50 so that the user can watch the broadcast through the monitor 50. .

At this time, when the reception state of the broadcast signal is deteriorated and the vertical synchronization signal is not constant, the user may view a deteriorated screen in which the vertical synchronization is broken.

Therefore, in the present invention, first, the broadcast signal received by the image signal processing unit 40 is detected (step 200), and the microcomputer 20 uses the detected reception sensitivity signal to detect the received sensitivity lower than the preset reference sensitivity. (Step 202).

At this time, if the detected reception sensitivity is lower than the preset reference sensitivity, the microcomputer 20 generates a pseudo vertical synchronization signal that matches the standard specification of the broadcast signal and applies it to the deflection processor 70, and the deflection processor 70 Deflection control is performed by using the pseudo vertical synchronizing signal applied from the microcomputer 20 in synchronization with the vertical synchronizing signal from the synchronizing separation unit 60 (step 204).

Next, the microcomputer 20 counts and stores the period of the vertical synchronization signal separated from the synchronization separation unit 60 while performing deflection control with a pseudo vertical synchronization signal conforming to the standard of broadcast signal. (Step 206).

Next, an average value of the counted predetermined number of periods is calculated (step 208) to generate a pseudo vertical synchronizing signal having the calculated average period, and the pseudo vertical perpendicular to the standard of the broadcast signal applied to the deflection processing unit 70. The output of the synchronization signal is stopped (step 210), and a pseudo synchronization signal having a calculated average period is applied to the deflection processing unit 70 (step 212).

Then, the deflection control unit 70 applies the deflection signal to the monitor 50 based on the pseudo vertical synchronizing signal having the calculated average period from the microcomputer 20 (step 214), and the noise is reduced when the reception sensitivity is lowered. This prevents false detection of the vertical synchronization signal.

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, there is an effect that the vertical synchronization of the screen can be prevented from being collapsed irregularly by preventing the false detection of the vertical synchronization signal due to noise when the reception sensitivity is lowered in the television.

Claims (2)

A method for processing vertical sync when reception sensitivity is lowered in a television, Detecting a reception sensitivity of a received broadcast signal; Separating and deflecting a vertical synchronization signal included in a broadcast signal when the detected reception sensitivity is equal to or greater than a preset reference sensitivity; Counting and storing a cycle of the vertical synchronization signal separated from the broadcast signal by a predetermined number of times if the detected reception sensitivity is lower than a reference sensitivity; And generating and deflecting a pseudo vertical synchronization signal having the calculated average period by calculating the average period of the stored period. The vertical synchronization control method of claim 1, wherein a pseudo vertical synchronization signal according to a standard standard of a broadcast signal is generated and deflected during the period count and average period operation of the vertical synchronization signal.