Television signal distinction device and television signal distinction manner

摘要

PROBLEM TO BE SOLVED: To allow a device to discriminate standard/nonstandard television signals without being affected by external disturbance or the like. ;SOLUTION: A horizontal synchronizing signal of a television signal is counted by a counter 3. A window circuit 2A generates a window signal within a range of a prescribed count where vertical synchronizing signals are in existence. A television signal is discriminated as a standard television signal when a number of vertical synchronizing signals are consecutively in existence in a period of the window signal, while it is discriminated as a non-standard television signal when a number of vertical synchronizing signals are not consecutively in existence in a period of the window signal. Since the standard or nonstandard television signal is discriminated with a hysteresis, the television signal is stably discriminated.;COPYRIGHT: (C)1999,JPO