| 摘要 |
<p>PURPOSE:To prevent a user from failing to reproduce a recorded picture by automatically stopping recording or stopping recording by the user in response to an alarm at the time when drum phase servo is off and cannot be followed by a servo circuit. CONSTITUTION:A signal CT and a signal SF are supplied to a microcomputer 30, and the phase difference between both signals is detected by a phase difference detecting process 31. A servo off duration discriminating process 32 discriminates whether the absence of the fall of the signal SF is continued for a prescribed time or longer in the width of period OK or not; and if it is discriminated that the servo off state is continued for the prescribed time or longer, the recording mode state is released and tape running is stopped and shut off by the discrimination output, or an alarm tone is emitted or an alarm lamp is lit. Thus, the state that reproduced pictures cannot be obtained at all is prevented.</p> |
