| 摘要 |
PURPOSE:To control a position properly and stably by constituting such that write is stopped when the comparison output of a comparing means is out of the prescribed range. CONSTITUTION:When a movable part acts abnormally, the output of the comparing means is out of the prescribed range and re-write by a write means is stopped. Namely, the output V0 of the comparing means 7 is impressed to another window comparator 13.Its comparison level goes to VHB>VHZ and VLB<VLA. When a pickup 3 fluctuates considerably due to an exogeneous parameter and the output V0 of the comparing means 7 goes to V0>VYHB or V0<VLB, the output of a gate 14 goes to 'H' level, and gates 11a and 11b are closed. The value of a counter 8 is held a value immediately before the pickup 3 has fluctuated due to the exogeneous parameter, and simultaneously a switch 6 is switched to a side (b) from a side (a) to stop the drive of a linear motor 4. Thus a position can be controlled properly and stably. |
