Erasing disk surface by direct current applied on a helical trajectory to minimize erase time

Abstract

A method of erasing a disk by applying a direct current to a transducer while the transducer is moved in a selected manner relative to the rotating disk. The rotating disk in conjunction with the erasing transducer moving in a first direction in a substantially continuous and smooth manner yields a helical shaped erased path on the disk. Such helical erasure of the disk is faster than conventional erasure method that erases the disk by erasing in concentric circular paths. To erase in circular paths, the transducer needs to be positioned on that circular path, and positioning of the transducer involves a repositioning time that can be significant. The helical erasure method substantially eliminates the repositioning time since the path of the transducer is substantially continuous and smooth. The reduction in erasure time by use of helical erasure method is substantial when compared to the total erasure time.

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