| 摘要 |
PROBLEM TO BE SOLVED: To provide a circuit for detecting video signal level detecting accurately only a normal channel having an accurate reception enable level in the automatic channel retrieval and storage mode. SOLUTION: A composite video signal S1 is separated into a synchronizing signal S2 and a color burst signal S4 at a synchronizing separator circuit 12 and a color burst signal separate circuit 24. Then a level of each signal is detected and when each signal level is a reference voltage (VREF1 , VREF2 ) or over respectively, a logic gate 31 provides an output of a signal. |
