Synchronization Signal Extraction Device and Related Method

A synchronization signal extraction method comprising:

• receiving a composite video signal;
• adjusting a threshold voltage to a ratio of a first characteristic level and a second characteristic level of the composite video signal according to the first characteristic level and the second characteristic level;
• slicing the composite video signal to extract a synchronization signal in the composite video signal according to the threshold voltage;
• and
• outputting the extracted synchronization signal.

A synchronization signal extraction device comprising:

• a signal reception terminal for receiving a composite video signal;
• a threshold voltage adjuster, coupled to the signal reception terminal, for outputting a threshold voltage according to a first characteristic level and a second characteristic level of the composite video signal, wherein the threshold voltage is a ratio of the first characteristic level and the second characteristic level;
• a multiplexer, having a first input terminal coupled to the threshold voltage, a second input terminal coupled to a predetermined threshold voltage, and an output terminal, for selectively outputting the threshold voltage or the predetermined threshold voltage via the output terminal;
• a slicer, coupled to the signal reception terminal and the output terminal of the multiplexer, for slicing the composite video signal to extract a synchronization signal in the composite video signal according to the threshold voltage or the predetermined threshold voltage;
• and
• a signal output terminal, coupled to the slicer, for outputting the extracted synchronization signal.