| 摘要 |
PURPOSE:To erase all the data on a floppy disk in a short time by making the travel speed of a magnetic head into a width narrower than the width of the recording track of the floppy disk for one rotation of the floppy disk. CONSTITUTION:The date recorded on a floppy disk 1 are erased by scanning on the floppy disk 1 with the magnetic head to draw a spiral locus 2 and applying a d.c. current to the magnetic head. Further, the spiral locus 2 is realized by continuously and linearly moving the magnetic head from the outer circumference of the floppy disk to the center of the floppy disk with a minute feed while rotating the floppy disk. The feed quantity of the magnetic head at this time is made into the width narrower than the width of the recording track for one rotation of the floppy disk. Thus, a data erasing operation can be executed without any interruption, and all the data on the floppy disk can be erased in a short time. |
