Novel NRRO minimization algorithm for an ultra-high-density servo track writer

Author

Noda, Kohki ; Naoe, Masahiko

Author_Institution

IBM Japan Ltd., Yamato, Japan

Volume

33

Issue

5

fYear

1997

fDate

9/1/1997 12:00:00 AM

Firstpage

2626

Lastpage

2628

Abstract

Since the introduction of magnetoresistive (MR) heads, the areal density of hard disk drives (HDDs) has been increasing at a rate around 60% a year, and the track density is increasing at roughly half that rate. The servo track writer (STW), which is used to write accurate servo patterns for head positioning on the surfaces of disks in the HDD, is a key instrument in this regard. A novel algorithm for the STW of the sector-servo architecture, using an accurate air-bearing motor and rotary-positioner, and a repeatable runout (RRO) compensation method, is proposed in order to minimize the effects of nonrepeatable runout (NRRO) components, which are generated by a spindle motor and other mechanical components of the HDD, and have a dominant influence in retarding track density growth

Keywords

hard discs; minimisation; servomechanisms; NRRO minimization algorithm; air-bearing motor; areal density; hard disk drive; magnetoresistive head; nonrepeatable runout; rotary positioner; spindle motor; track density; ultra-high-density servo track writer; Hard disks; Instruments; Magnetic heads; Magnetoresistance; Minimization methods; Rail to rail outputs; Rough surfaces; Servomechanisms; Servomotors; Surface roughness;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.617429

Filename

617429