Browse Prior Art Database

DASD with Random Rotational Stopping of Slider on Disk

IP.com Disclosure Number: IPCOM000111920D
Original Publication Date: 1994-Apr-01
Included in the Prior Art Database: 2005-Mar-26
Document File: 2 page(s) / 62K

Publishing Venue

IBM

Related People

Best, GL: AUTHOR

Abstract

The invention disclosed is a disk drive able to stop the slider on the disk at a predetermined "random" rotational position in order to minimize disk wear and wear-induced increases in the stiction between the disk and slider.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

DASD with Random Rotational Stopping of Slider on Disk

      The invention disclosed is a disk drive able to stop the slider
on the disk at a predetermined "random" rotational position in order
to minimize disk wear and wear-induced increases in the stiction
between the disk and slider.

      Current techniques for reducing disk wear involve application
of lubricants or protective overcoats to the disk, or random radial
placement of the slider on the disk to distribute the wear across the
disk.  However, these methods have their drawbacks.  Although
application of a lube decreases disk wear, it has the disadvantage of
increasing stiction.  Overcoats do not necessarily increase stiction,
but usually must be used in conjunction with a lube.  Random radial
placement of the slider on the disk does not spread wear evenly
across the disk, since a "landing" track can be chosen, but a
rotational stopping position can not.  Furthermore, the slider
suspension geometry can actually cause the slider to dig into the
disk if pulled sideways during radial placement.

      The present invention distributes slider to disk wear evenly
over an entire Inner Diameter (ID) track by using random rotational,
rather than radial, slider positioning.  The process may be
implemented in several ways, as described below.

      The stopping position may be determined by using the randomness
of drive turnoff combined with motor cogging.  Random timing of motor
deceleration is provided by the inherent randomness of drive turn off
without any optimization.  Assuming the drive decelerates in a
similar manner each time, the...