CIRCUIT FOR PREVENTING OSD TREMBLING ON WEAK SIGNAL IN TELEVISION RECEIVER

摘要

PURPOSE: A circuit is provided to prevent OSD(On screen display) trembling in a television receiver when a level of a received synchronous signal is weak. CONSTITUTION: The circuit comprises: a transistor(Q1) whose base terminal is connected to a synchronous signal input unit and collector terminal is connected to a micom(400); a power input terminal(B+) connected to the collector of the transistor via a resistor(R1); a synchronous signal generating unit(500) for generating a synchronous signal which has the same period with the synchronous signal of the synchronous signal input unit; an inverter for inverting the synchronous signal of the synchronous signal generating unit; and a zener diode(700) of which one end is connected in parallel between the inverter and the micom and the other end is grounded.