Hitachi Global Storage Technologies Netherlands B.v.

Hgst Netherlands, B.v.

Maxtor Corporation

Kezhao Zhang

Shanlin Duan

Jane Jie Zhang

Zhupei Shi

Zhen Jin

Erhard Theodor Schreck

Don Brunnett

Gang Herbert Lin

Duc H Banh

Jizhong He

Jingbo Yu

John Vicars

Suet Teo

Nick Warner

Kurt Rusnak

Approaches for a testing device for selecting a discrete track media (DTM) format for use with a particular head of a hard-disk drive (HDD). The testing device comprises a continuous magnetic-recording disk, rotatably mounted on a spindle, which stores data using a continuous media format. The testing device also comprises a testing module configured to simulate reading data, stored using a discrete track media (DTM) format, from the continuous magnetic-recording medium. Advantageously, testing time and cost is reduced as both discrete track media (DTM) disks and expensive discrete track media (DTM) recording testing hardware are not required to select the optimal a discrete track media (DTM) format for use with a particular head of a hard-disk drive (HDD). In addition, embodiments may be used to optimize features of the tracks of the DTM disk, such as the land to groove ratio.

Simulating discrete track media with continuous media for head evaluation

Magnetic disk drive systems and associated methods are described for testing magnetic disk performance for certification with a plurality of magnetic disk drive systems prior to installation. The test system may position a slider at a first spacing between the magnetic disk in the slider and simulate the recording performance of a disk drive system with the magnetic disk at the first spacing. The disk drive test system may then transfer a control signal to a heating element in the slider to move the slider to a different spacing between the magnetic disk and the slider to simulate the recording performance of another disk drive system. The test system may, thus, use a single slider to certify a magnetic disk with a plurality of disk drive systems.

Testing magnetic disk performance with a single slider simulating sliders of various disk drive systems

Track pitch in a hard disk drive is selected to satisfy the requirements of both off-track capacity (OTC) and adjacent track interference (ATI). The invention separately measures the track pitch requirements for OTC and ATI. The track pitch for the drive is set with the larger of the OTC and ATI track pitches. The OTC track pitch is measured with a 747 curve, and the ATI track pitch is measured by the positions of adjacent tracks at which the on-track error rate is not worse than a given value after the targeted number of adjacent track writes in the ATI requirement.

System, method and apparatus for determining track pitch in a hard disk drive to satisfy the requirements of both off-track capacity and adjacent track erasure

Methods and test systems are disclosed for determining the quality of an erase process for perpendicular magnetic recording (PMR) disks. After performing an erase process on a PMR disk and before the PMR disk is assembled into a hard disk drive, a first test pattern of magnetization pulses is written to a region of the PMR disk. A second test pattern is subsequently read from the region of the PMR disk. The second pattern of magnetization pulses is analyzed in relation to the first test pattern and measured to determine the quality of the erase process.

Determination of the quality of an erase process for perpendicular magnetic recording disks

A method of determining side track erasure in a disk drive having a disk and a transducer. A target track and one or more side tracks proximate to the target track on the disk are selected, and recording parameters for recording signals on the target track and each side track with the transducer are selected. Thereafter, signals are recorded on each side track and then signals are recorded on the target track multiple times. A reduction in the integrity of the recorded signals on each side track due to recording signals on the target track multiple times is detected, and the detected reduction in the integrity of the recorded signals on each side track represents the amount of the erasure of the recorded signals on the side track. Recording parameters are changed based on the signal integrity reduction to minimize side track erasure.

Method of determining side track erasure in a disk drive

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Fremont, CA, United States of America

Kezhao Zhang