| 摘要 |
PURPOSE:To reduce metallic sounds produced in both the lock and lock release modes and to prevent a case where the door of a floppy disk is opened by malfunction, by performing the intermittent locking actions with no lock start nor release action against the intermittent lock actions carried out within a prescribed period of time. CONSTITUTION:A head drive starting signal 11 produced at the rise of the second command signal C is supplied to an FF2 and a timer 1 at a time point t5 before the count value of the timer 1 reaches (n). The count value of the timer 1 is set again at the initial value 0 and the counting action of the timer 1 is stopped. Then the drive of an electromagnetic solenoid 4 is continued together with the output of an output signal 14 of the FF2. While a head drive stop signal 12 produced at the falling of the signal C is supplied to the timer 1 at a time point t7 and the timer 1 restarts its counting action at a time point t8. When the count value of the timer 1 exceeds (n) at a time point t9, an output signal 13 is supplied to the FF2 at a time point t10. Thus the FF2 is reset. As a result, the supply of the signal 14 to a driver circuit 3 is stopped and the drive of the solenoid 4 is discontinued. Then the lock is released for the door of a floppy disc.
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