Synhchronizing signal recovery system

PURPOSE: To realize stable synchronizing signal recovery by adding a function stopping an inhibit function for a prescribed time from the moment when an input VBS signal is inputted, to the system. CONSTITUTION: Upon the receipt of an input VBS signal, an input signal detection section 104 gives a signal of input 'presence' to a control section 109 from an input signal detection section 1-4. The control section 109 uses an input detection signal of the input signal detection section 104 as a trigger to generate a pulse for a prescribed time (a time after the operation of a crystal oscillator system AFC section 101 is finished or over). An inhibit pulse generating section 108 resets an inhibit pulse output during pulse period. Thus, a set pulse output of a set pulse generating section 107 keeps setting a 1/910 counter 105 for a prescribed time. After the prescribed time, the inhibit pulse of the pulse generating section 108 is set by a control section 109 and a set pulse is not inputted to the counter 105 of the inhibit section 106. Accurate synchronization coupling is attained by applying inhibit after the AFC operation of the crystal oscillator system AFC section is completely finished. COPYRIGHT: (C)1993,JPO&Japio