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Browse Prior Art Database

Simple Head Positioning Method

IP.com Disclosure Number: IPCOM000117838D
Original Publication Date: 1996-Jun-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 4 page(s) / 73K

Publishing Venue

IBM

Related People

Endoh, T: AUTHOR [+3]

Abstract

Fig. 1 shows a graph showing the velocity of a head in each position on a disk in a sweep mode. This new method can achieve to sweep all tracks by a head Air Bearing Surface (ABS) edge.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Simple Head Positioning Method

Fig. 1 shows a graph showing the velocity of a head in each position
on a disk in a sweep mode.  This new method can achieve to sweep all
tracks by a head Air Bearing Surface (ABS) edge.

      Disclosed is a simple head positioning method.  Conventionally,
Voice Coil Motor (VCM) current has to be calculated and adjusted to
achieve a desired head motion.  Some complicated calculations must be
executed by micro-code.

      New method achieves a desired head motion in a simple and
effective way.  This head motion control is executed by specifying
the number of tracks to skip and the duration of a constant head
speed.

      Conventionally, for sweeping the entire disk surface with a
head, the head speed has to be kept at or below certain speed.
Conventionally, an ideal sweep speed or a constant sweep speed is
determined by microcode.

      This method does not need any complicated calculation by
microcode.  It only requires a table specifying the number of tracks
to skip and a duration of maintaining a constant velocity of the
head.  This is a simple and easy method compared to the current
method.

Fig. 2 shows a graph showing Number (#) of tracks to skip in each
position on a disk.  Advantages using this new method are:
  (A) Easiness in implementation, modification.
  (B) Reduction of time for a head positioning.

Application

This new method can also be used for eliminating Thermal Asperity
(TA) on a disk.