Mobile Storage Technology, Inc.

Samsung Electronics Co., Ltd.

Integral Peripherals, Inc.

Dan A Hunter

Michael R Utenick

James H Morehouse

James M Jones

Nelson Chenkin

Thomas L Andrews, Jr

A velocity-controlled actuator system and method are usable in low velocity, high load situations such as those encountered in dynamic head loading, and in normal situations. The velocity-controlled actuator system utilizes a self-tuning estimator that is calibrated during operation of said disk drive. Consequently, parameters, characteristics, and any other features of the disk drive that affect operation of the actuator system are compensated for in real time by the calibration process. The velocity-controlled actuator system dynamically adjusts the actuator resistance utilized in the reconstruction of the back EMF voltage by utilizing a self-tuning estimate of the actuator resistance that compensates for any changes in the actuator resistance over time.

Method for precise velocity feedback control in an actuator system of a

An enhanced method and system for unloading magnetic heads are disclosed. The system limits the maximum and minimum speed of the actuator while unloading the heads during a power failure. A BEMF control circuit monitors the velocity of the actuator using the BEMF of the actuator as a gauge of the velocity. The BEMF control circuit uses a sense resistor to remove the inherent resistive component of the actuator from its BEMF measurement. If the velocity of the actuator increases above a safe level the BEMF control circuit decreases actuator current to prevent further acceleration. If the velocity of the actuator decreases below a safe level the BEMF control circuit increases the actuator current to accelerate the actuator to a safe level.

Enhanced method and system of unloading magnetic heads

Time dependent velocity-controlled disk drive actuator system

A method for optimizing the storage capacity of miniature disk drives without affecting reliability or yields of the disk drives uses an iterative seek process to define track zero. Initially, a physical reference point is defined and a transducer is moved in coarse steps from the physical reference point until interference with a stationery loading ramp or other mechanical component, hereinafter, 'ramp,' is detected. Upon detection of interference, the transducer is moved one coarse step away from the ramp and then the transducer is moved in fine steps towards the ramp until interference is again detected. Upon detection of interference, the transducer is moved away from the ramp a predetermined distance. After the transducer is moved the predetermined distance, a check is made for interference. If interference is detected, the transducer is moved in fine step towards the center of the disk until interference is no longer detected. When interference is no longer detected, the transducer is moved a predetermined distance and the resulting location of the transducer is defined as track zero.

Method for optimizing track location during servo writing

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Boulder, CO, United States of America

Dan A Hunter