Patent ID: 7522216
Filing Date: 2009-04-21
Classification: H04N

Abstract:
1. An apparatus including a video synchronization signal detector for detecting occurrences of single and double frequency synchronization signal pulses present during a vertical synchronization interval, comprising: voltage generating circuitry responsive to a reset control signal by providing a generated voltage that alternately charges and discharges to first and second values during first and second states of said reset control signal, respectively; voltage detection circuitry coupled to said voltage generating circuitry and responsive to said generated voltage by providing a reference voltage corresponding to a maximum value of said first generated voltage value attained during one or more earlier ones of said first reset control signal state; and control circuitry coupled to said voltage detection circuitry and said voltage generating circuitry, and responsive to at least said generated voltage, said reference voltage and a horizontal synchronization signal with first and second signal states and one or both of single and double frequency synchronization signal pulses during a vertical synchronization interval, by providing