Seagate Technology Incorporated

Other

Jimmy Tze Ming Pang

Kevin Arthur Gomez

Qiang Bi

Aik Chuan Lim

BengSee Lim

Stephen Kow Chiew Kuan

MengEng Lye

A method of, apparatus for, and means for controlling pitch of a servowritten track on a disc in a disc drive are disclosed. The disc drive has a head for traversing over a surface of the disc. The head has a read element and a write element separated by a head element offset &Dgr;. A servowriting controller operably connected to the disc drive creates a track k by writing servo information on the disc. The servowriting controller then calculates the head element offset &Dgr; at the track k, &lsqb;&Dgr; (k)&rsqb; and determines a skew angle &thgr; at the track k, &lsqb;&thgr;(k)&rsqb;. The servowriting controller adjusts a track pitch correction factor based on the &Dgr; (K) and the &thgr;(k) such that the track pitch correction factor is utilized to servowrite a next track.

Track pitch control using head offset measurement for self-servowriting tracks in a disc drive

A method for optimizing the attenuation of mechanical resonances of actuator driving energy of a disc drive is presented. The method generally involves determining a resonant frequency range of the disc drive, comparing the resonant frequency range to a filter coverage limit, failing the disc drive if the resonant frequency range exceeds the filter coverage limit, and storing notch filter constants in servo flash memory of a servo control processor if the filter coverage limit is not exceeded by the range of resonant frequencies. The notch filter constants configure the notch filter to attenuate the frequencies of the driving energy produced by the servo control processor that are within the resonant frequency range. The notch filter is implemented by the servo control processor each time the disc drive is used. Also presented is a disc drive and a program that are capable of implementing the above-described method.

Notch filtering as used in a disc drive servo

A method of calibrating magnetoresistive (MR) head geometry for a product head in a selfservo writing disc drive includes the steps of writing a first burst at an inner diameter of a disc surface using the write head of the product head. Next, the first burst is read using the MR read head of the product head, and a first read amplitude of the first burst is determined. From the first read amplitude of the first burst, it is determined which one of a multiple different sets of subsequent inner diameter steps to perform. Then, the one of the multiple different sets of subsequent inner diameter steps is performed to determine a read head width, a write head width, and a read-write offset between the read head and the write head.

Method for calibrating MR head geometry in selfservo writing disc drives

Growing community of inventors

Singapore, Singapore

Jimmy Tze Ming Pang