Improvement of RRO using hybrid-type STW for hard disk drives

Author

Inoue, Takahiro ; Horisaki, Makoto ; Seo, Yousuke ; Yamazaki, Shizuo

Author_Institution

Data Storage & Retrieval Syst. Div., Hitachi Ltd., Kanagawa, Japan

Volume

37

Issue

2

fYear

2001

fDate

3/1/2001 12:00:00 AM

Firstpage

969

Lastpage

973

Abstract

Accurate servo track writers (STWs) are indispensable for hard disk drives (HDDs) with high track density. We have developed a prototype hybrid-type STW which has two writing stages. In the first stage, master patterns are written on one surface of the master disk prior to drive assembly. In the second stage, the master disk is assembled with several raw disks in a HDD, and the servo patterns are written on the all disks, including the master, based on the master patterns. In this paper, a new servo compensator and a new algorithm to compensate for position signal nonlinearity are proposed. These are necessary items for the hybrid-type STW. Finally, experimental results are described showing that the hybrid-type STW reduces the maximum value of repeatable runout (RRO) and write-to-write track mis-registration

Keywords

compensation; disc drives; hard discs; position control; servomechanisms; HDD; hard disk drives; high track density; hybrid type servo track writers; position signal nonlinearity compensation; repeatable runout reduction; servo compensator; servo patterns; write-to-write track mis-registration reduction; Assembly; Costs; Disk drives; Hard disks; Magnetic heads; Prototypes; Rail to rail outputs; Servomechanisms; Servomotors; Writing;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.917652

Filename

917652