Browse Prior Art Database

Power Save Mode in Hard Disk Drive

IP.com Disclosure Number: IPCOM000112553D
Original Publication Date: 1994-May-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 48K

Publishing Venue

IBM

Related People

Asano, H: AUTHOR [+3]

Abstract

This article describes the method to solve the head flying height problem at the landing zone in the modified idle mode. The modified idle mode is well known method to reduce the idle power by moving the head to the inner crash stop and powering off the Voice Coil Motor (VCM) driver.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 71% of the total text.

Power Save Mode in Hard Disk Drive

      This article describes the method to solve the head flying
height problem at the landing zone in the modified idle mode.  The
modified idle mode is well known method to reduce the idle power by
moving the head to the inner crash stop and powering off the Voice
Coil Motor (VCM) driver.

      The Hard Disk Drive (HDD) decreases the head flying height to
the minimum to gain the higher capacity.  The design point is changed
so that the minimum head flying height will be kept at the most inner
data zone.  With this design point, the modified idle mode can not be
implemented in HDD.

      This invention describes the method and the operation process
to realize the modified idle mode for the HDD in which head flying
height is minimum at the most inner data zone.

      If the spindle motor rotates fast, the head flying height will
increase as shown in the Figure.  The relation between the rotational
speed and the flying height can be determined from the mechanical and
head design.

      After the predetermined time has elapsed in the idle mode
without any operational commands issued from the host, the head will
be moved to the most inner data zone and the disk rotational speed
will be increased to the predetermined one.  The head will fly with
the minimum height at the landing zone.  When the disk rotational
speed comes to the predetermined one, the head will be moved to the
inner crash stop for the latch and th...