Browse Prior Art Database

Partial Head Disk Interface Preload Control to Enhance Shock/Disk-Durability Performance of a Portable Disk Drive

IP.com Disclosure Number: IPCOM000113706D
Original Publication Date: 1994-Sep-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 65K

Publishing Venue

IBM

Related People

Sri-Jayantha, M: AUTHOR [+2]

Abstract

The HDI shock damage and disk durability problems are simultaneously solved by means of a simple electromagnetic solenoid that controls the preload force during CSS. The disclosed invention allows an HDI system to have higher preload in sleep, power-off, or ready-mode and reduced preload during CSS phase only by adding an external force genterating device on to the HSA as shown in Fig. 1. The head remains in contact to avoid "load/unload" related problems.

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This is the abbreviated version, containing approximately 58% of the total text.

Partial Head Disk Interface Preload Control to Enhance Shock/Disk-Durability
Performance of a Portable Disk Drive

      The HDI shock damage and disk durability problems are
simultaneously solved by means of a simple electromagnetic solenoid
that controls the preload force during CSS.  The disclosed invention
allows an HDI system to have higher preload in sleep, power-off, or
ready-mode and reduced preload during CSS phase only by adding an
external force genterating device on to the HSA as shown in Fig. 1.
The head remains in contact to avoid "load/unload" related problems.

      The head-lift acceleration is governed by the mass of
head-suspension assembly (HSA) and preload force.  Increasing the
head preload, with appropriate slider air-bearing stiffness and
fly-height parameters, will proportionally increase the head-lift
acceleration.  However, increasing the preload, accelerates the disk
wear and degrades the CSS life of a disk.  Thereby limiting the
ability of an HDD system to provide effective power-saving (Sleep)
mode.

      A programmed level of current, i, is supplied to the solenoid
during the CSS mode only.  Once the air bearing surface is fully
developed, the current is removed.  The design assumes that the
suspension has ferromagnetic material in it, otherwise a thin film of
such material must be applied.  The partial HSA preload control is
ideally implemented in a single-disk based HDDs as shown in Fig. 2
where the solenoid is carried by...