Synchronizing signal detection protective circuit

A synchronizing signal detection protective circuit for detecting a synchronizing signal on a recording medium with information to be recorded and the synchronizing signal being consecutively recorded thereon, comprising:

• a first time gate circuit for generating a first time gate signal at a first predetermined time before an expected occurrence of said synchronizing signal;
• a second time gate circuit for generating a second time gate signal at a second predetermined time before said expected occurrence of said synchronizing signal, said second predetermined time occurring before said first predetermined time;
• a time gate signal switching circuit connected to said first and second time gate circuits and adapted to generate selectively one of said first time gate signal and second time gate signal;
• a synchronizing signal gate circuit connected to said time gate signal switching circuit and adapted to control the gating time for detecting said synchronizing signal in response to one of said first and second time gate signals;
• a compensatory synchronizing signal generating circuit for generating a compensatory synchronizing signal;
• and
• a synchronizing signal switching circuit which conducts the synchronizing signal when said synchronizing signal has been detected by said synchronizing signal gate circuit in response to either one of said first and second time gate signals, and conducts said compensatory synchronizing signal when the synchronizing signal has not been detected by said synchronizing signal gate circuit in response to said first time gate signal.