Being the field distinction manner which generates the field distinction signal field distinction

摘要

PROBLEM TO BE SOLVED: To provide a field discrimination method and circuit with a small scale circuit configuration that uniquely decides field discrimination independently of an initial state on the basis of a vertical synchronizing signal and a horizontal synchronizing signal of a received video signal.;SOLUTION: When a pulse signal denoting a vertical synchronizing signal and a pulse signal denoting a horizontal synchronizing signal are active in different timings, a logical value is brought into an L level every time the pulse signal denoting the vertical synchronizing signal is active and the logical value is inverted to the preceding value every time the pulse signal denoting the horizontal synchronizing signal is active and when the pulse signal denoting the vertical synchronizing signal and the pulse signal denoting the horizontal synchronizing signal are active in the same timing, the logical value is brought into an H level every time the pulse signal denoting the vertical synchronizing signal and the pulse signal denoting the horizontal synchronizing signal are active at the same time to generate a state signal and to use the logical value of the state signal when the pulse signal denoting the vertical synchronizing signal is active for a field discrimination signal.;COPYRIGHT: (C)2002,JPO