Samsung Electronics Co., Ltd.

Seung-chul Park

Kwang-jo Jung

Chang-ik Kang

Kyoung-Soo Kim

A method of calibrating a parameter to measure the back electromotive force (BEMF) of a voice coil motor (VCM), and a method and apparatus to use the calibrating method to perform unloading control. The calibration method includes: reading servo data and measuring a BEMF value while seeking two predetermined points on a disk, and storing the servo data and the BEMF value, generating an actual velocity curve of a head using the stored servo data, and an estimated velocity curve of the head using the stored BEMF value and adjusting a parameter related to a BEMF measurement to align the actual velocity curve of the head with the estimated velocity curve of the head.

Back electromotive force (BEMF) calibration method, method of controlling unloading of disk drive apparatus using BEMF calibration method, and disk drive apparatus using the same

An optimal track zero determination method used in a hard disk drive and a hard disk drive using the method. The method has the operations: (a) performing a sequential seek operation on target tracks of a disk, in units of predetermined numbers of tracks, outwardly, from a track separate from a physical track zero position obtained in a servo track write operation, by a predetermined distance toward the physical track zero position; (b) determining whether the target tracks belong to a region where a track-following operation is normally performed, and determining whether an actuator arm connected to a transducer is in contact with a mechanical buffering unit during the sequential seek operation of operation (a); and (c) selecting as a logical track zero, the target track belonging to the region where the track following operation is normally performed and the actuator arm is not in contact with the mechanical buffering unit.

Track zero determination method used in data storage system and disk drive using the same

A method and apparatus for controlling a track seek servo of a disk drive. The method of controlling the track seek servo of the disk drive having a transducer and a disk with a plurality of tracks, includes moving a transducer to a space over a target track of the plurality of tracks according to a track seek controlling process in which an asymmetrical sine wave acceleration trajectory a(t) is used in a track seek mode.

Method and apparatus for controlling track seek servo of disk drive

A head of a disc drive is decelerated after being accelerated, according to a desired deceleration profile for minimizing damage to the head. The desired deceleration profile is determined from an acceleration profile used for accelerating the head before decelerating the head. With such a desired deceleration profile the head is parked with substantially zero speed by an end of the desired deceleration profile to minimize damage to the head.

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Suwon-si, South Korea

Seung-chul Park