Abstract: An adaptive velocity profile system is provided for variably controlling a disk drive head in a computer disk drive or the like, to obtain substantially minimum seek times in accordance with variable operating conditions. The system monitors actual performance of the head in the course of a seek step during which the head is displaced relative to a memory storage disk for alignment with a selected track on the disk, and wherein the head performance is variable in response to a range of parameters such as temperature, power supply voltage, mechanical stiffness, etc. The monitored head performance as represented, for example, by head acceleration at the initiation of a seek step and/or by a track address mismatch at the conclusion of a seek step is used, in the preferred form, to select an appropriate one of several available velocity profiles for controlled head deceleration at the conclusion of a subsequent seek step.
Abstract: An offset nulling system is provided for use in computer disk drives to identify and compensate for actuator head position offset errors attributable to dc offsets of the disk drive control circuitry, thereby obtaining improved head alignment wiht a designated track on a memory storage disk or the like. The system includes a microcontroller adapted during a calibration mode to identify the position offset error and direction for selected tracks located respectively at radially inner and radially outer regions of the disk, and to adjust head position incrementally relative to those tracks to subsantially eliminate position offset error. Thereafter, during a normal operation mode of the disk drive, the microcontroller functions at the conclusion of a track seek step to adjust the head through a position offset compensation value and direction derived by interpolation of the position offset compensation value and direction identified during the calibration mode, in accordance with the specific track address.
Abstract: An actuator assembly for a disk drive system includes an actuator pivotally mounted to a shaft, and a coil assembly. A counterbalance portion of the actuator provides a recess wherein a portion of the coil assembly is slidably inserted. The coil assembly includes a bobbin which has a dovetail portion having at least two precision positioning surfaces which, when placed within the counterbalance recess, interact with corresponding precision positioning surfaces provided within the counterbalance recess. In order to accurately position the coil assembly with respect to the actuator, an outward force is applied to the coil assembly perpendicular to the pivot axis to cause facing pairs of the precision positioning surfaces of the coil assembly and the counterbalance recess to bear against one another, and align a dowel/pin alignment passageway extending through the counterbalance with a dowel/pin recess provided in the bobbin.
March 25, 1988
Date of Patent:
November 7, 1989
Joseph M. Sampietro, Khosrow Mohajerani
Abstract: An assembly station is provided for use in the assembly of disk drive units of the type used in microcomputers, such as personal computers and the like. The assembly station comprises a main platform having a head fixture and a disk fixture for respectively receiving and supporting a head actuator subassembly and a disk subassembly of a disk drive unit. The disk fixture supports the disk subassembly for sliding displacement into precision registry with the actuator subassembly to accommodate facilitated mounting of a housing base onto the actuator and disk subassemblies. In the preferred form of the invention, the assembly station is further adapted to receive and support additional disk drive components for mounting within the housing base. The platform is adapted for inversion to expose these additional disk drive components through platform openings for relatively simple attachment to the housing base at predetermined positions.
Abstract: A motor control system and related method are provided for phase and frequency locked operation of multiple spindle motors in a computer disk drive environment or the like, for coupling two or more disk drive units together to provide expanded data storage capability. The control system comprises a hybrid digital and analog network for producing a pulse width modulated control signal to control a disk drive spindle motor in a manner achieving frequency and phase locked relation with a reference signal. Multiple spindle motors are similarly driven in relation with the same reference signal, whereby the spindle motors are frequency and phase locked with respect to each other to permit, for example, parallel data transfer among the multiple disk drive units.