| 摘要 |
PURPOSE:To decrease considerably the difference of thickness of a film between the inner and outer circumference parts of a magnetic disk which is produced after the working, by changing the feeding speed of a tape head in order to control freely the working quantity of the magnetic disk. CONSTITUTION:A base 9 which holds a table head 17 moves a tape head 17 toward the radius direction 13 of a magnetic disk 1 by means of revolutions of a lead screw 11 of a servo motor 10 to give the working to the entire surface of the disk 1. A rotary encoder 14 which turns synchronously with the revolution of the motor 10 delivers pulses, and a pulse counting part 15 counts the prescribed pulses. Then a servo motor driving circuit 16 changes the number of revolutions. The relation is set optionally between the pulse count number and the control voltage to change freely the reciprocal motion speed of the base 9. In such a way, the working quantity of the disk 1 can be freely controlled. This can decrease considerably the difference of thickness of a film between the inner and outer circumference parts of the disk 1 which is produced after the working. |
