KR940023200A - On-screen display method and device therefor - Google Patents

Abstract

The present invention relates to a method and an apparatus for preventing the shaking of an on-screen display signal generated during no signal, comprising: a synchronous separator for separating a first synchronous signal from a composite video signal; Switching ON / OFF according to the control signal of the non-signal detection unit and the non-signal detection unit which detects whether or not the composite video signal is non-signaled using the synchronization signal, and generates a control signal corresponding to the detection result. When the first synchronous signal is applied from the synchronous separator, the second synchronous signal and the deflection signal which are phase-locked to the first synchronous signal are generated, and the first synchronous signal is not applied, and the third synchronous signal and the deflection by the self oscillation are generated. A deflection signal generator for generating a signal and an OSD unit for outputting an on-screen display signal in synchronization with a synchronization signal applied from the deflection signal generator.

Description

On-screen display method and device therefor

Since this is an open matter, no full text was included.

2 is a block diagram illustrating an embodiment of an on-screen display device according to the present invention.

Claims (5)

An on-screen display device for synthesizing and displaying an on-screen display signal to a composite video signal, the on-screen display device comprising: a sync separator for separating a first sync signal from the composite video signal; Converts the first synchronization signal applied from the synchronization separator into a voltage value of a DC component, and generates a first control signal when the voltage value has a value between a plurality of reference voltage values having different values; A signal-free detector for generating a second control signal when the reference voltage value of the signal is out of the range; A switching unit connected between the synchronization separating unit and the deflection signal generating unit, turned on by a first control signal of the non-signal detecting unit, and turned off by a second control signal; When the first synchronization signal is applied from the synchronization separator, a second synchronization signal and a deflection signal phase-locked to the first synchronization signal are generated. If the first synchronization signal is not applied, the third synchronization signal and A deflection signal generator for generating a deflection signal; And an OSD unit configured to output an on-screen display signal in synchronization with a synchronization signal applied from the deflection signal generator. 2. The apparatus of claim 1, wherein the signal-free detection unit comprises: means for converting the first synchronization signal applied from the synchronization separation unit into a constant voltage value in proportion to frequency; A reference voltage setting unit configured to apply a predetermined first reference voltage and a second reference voltage greater than the first reference voltage; A comparator including a first comparator for comparing the voltage of the first synchronization signal and the first reference voltage, and a second comparator for comparing the voltage of the first synchronization signal and the second reference voltage; And a control unit generating a first control signal when the voltage of the first synchronization signal is between the first reference voltage and the second reference voltage, and generating a second control signal when the two reference voltages deviate from each other. On-screen display device. The on-screen display device according to claim 2, wherein the controller controls an output of an on-screen display signal from the OSD unit. An on-screen display method for synthesizing and displaying an on-screen display signal to a composite video signal, comprising: dividing a first synchronization signal from the composite video signal; Detecting whether a composite video signal is free from the first synchronization signal; Blocking transmission of the first synchronization signal when the composite video signal is detected as no signal; Generating a second synchronization signal phase-locked to the first synchronization signal when the first synchronization signal is applied, and a third synchronization signal when transmission of the first synchronization signal is interrupted; And outputting the on-screen display signal in synchronization with one of the second and third synchronizing signals. 2. The method of claim 1, further comprising: converting the no signal detection step into a voltage value proportional to the frequency; Comparing the voltage value with a plurality of preset reference voltage values; And determining that the composite video signal is no signal when the voltage value is detected as a value between a plurality of reference voltage values. ※ Note: The disclosure is based on the initial application.