Patent ID: 7010214

Claim:
An apparatus for detecting a VCR signal comprising: a horizontal tracking portion for receiving a synchronous signal of an image signal and a system clock signal, for determining and outputting a phase error between the synchronous signal and a standard horizontal synchronous signal generated by the system clock signal, and for generating a horizontal synchronous signal and a vertical synchronous signal in response to the system clock signal; and a VCR signal detecting portion for receiving the vertical synchronous signal, the horizontal synchronous signal, and the phase error, and for detecting a video cassette recorder (VCR) signal, wherein the horizontal tracking portion comprises: a phase comparator for receiving the synchronous signal and the system clock signal, and for generating the phase error as a phase difference between the synchronous signal and the standard horizontal synchronous signal at every horizontal line; a pixel counter for receiving and counting the system clock signal; and a timing generator for receiving an output of the pixel counter, and for generating the horizontal synchronous signal and the vertical synchronous signal; and wherein the VCR signal detecting portion comprises: a head switch pulse period generator which is reset by the vertical synchronous signal, receives the horizontal synchronous signal, and determines a specific pulse period as a head switch pulse period; and a VCR signal detector for receiving the phase error during the head switch pulse period, and for detecting the synchronous signal as the VCR signal if the phase error exceeds a specific standard phase error value.