| 摘要 |
PURPOSE:To prevent a nozzle generated on an screen during a head moving period by inserting the preceded video signal duing the head moving period. CONSTITUTION:An operator depresses a button to output head acess indication signal for a fixed period. The initial synchronizing clock pulse after the output of the access indication signal outputs a pulse from an AND gate 16 and an RSFF 17 is set up to turn a Q output to a high level. During the high level period, a head access control circuit 18 controls a pulse motor 19 to move the head in a prescribed direction at a fixed speed. An access position setting circuit 191 set up the time and direction of head access before the access, and after passing said setting time from the trigger of a timer 21 by an output pulse from an AND gate 16, the time 21 outputs a pulse with the high level and the pulse resets the RSFF 17, turns the Q output to the low level and stops the head at a specified track position. The output pulse of the gate 16 resets an FF 22 and turns switches 4, 8 to the (a) sides respectively. |
