Abstract: A method of manufacturing a disk drive is disclosed in which servo information is written in tracks on a disk surface, the track width performance of the associated read/write transducer is measured, the track width performance is analyzed and a data track pitch is established. Based on the data track pitch established, a track location formula for data tracks on the surface is defined. For a disk drive with a plurality of read/write transducer-media surface combinations, a track location formula for data tracks is established for each combination.

Abstract: A mass moves within a bore defined in a body. During normal operation the axis of the bore is approximately vertical, so that the mass rests at the bottom. A magnet is positioned adjacent the top of the bore and imparts an upwards force on the mass that is less than the downwards force on the mass upwards force on the mass that is less than the downwards force on the mass from gravity. A coil is positioned adjacent the bottom of the bore. When the body is dropped, or tilted beyond a critical angle from vertical, the force from the magnet causes the mass to move upwards in the bore. The upwards movement is sensed as a change in the coil's inductance.

Abstract: A hard disk drive assembly is electrically connected to a printed circuit board assembly motherboard using a connector on the hard disk drive assembly connected with a mating connector mounted on the motherboard. The hard disk drive assembly is secured to standoffs that allow sufficient space between the hard disk drive assembly and the motherboard for an integrated circuit package to be positioned between the hard disk drive assembly and the motherboard.

Abstract: Disclosed is a method to reduce external signal interference with signals in a computer disk storage system including a disk drive. An electrically conductive housing is provided for the disk drive to enclose and support within the housing analog circuitry, a motor for rotating media for the storage of information, and circuitry for converting analog signals to digital signals. Circuitry and conductors which carry analog signals are enclosed within the electrically conductive housing and signal conversion circuitry is provided within the housing to convert analog signals into digital signals before transmission to the exterior of the housing.

Abstract: A method of manufacturing a disk drive which includes a disk having first and second magnetic surfaces and first and second read/write transducers for writing information on and reading information from the magnetic surfaces. The method includes determining a track width performance characteristic to be measured for the read/write transducers, establishing ranges of values for the performance characteristic to define a plurality of performance groups. The performance characteristic is measured for a plurality of read/write transducers from which the first and second read/write transducers for the disk drive are to be selected and the read/write transducers are segregated into groups based on the performance characteristic value falling within the range of the group. The disk drive is assembled using read/write transducers from only one of the groups. The measurement of the performance characteristic is accomplished either electrically or optically.

Abstract: A method for operating a disk drive apparatus in the Idle Mode reduces power consumption while meeting non-operating shock and vibration specifications. This is achieved by operating the disk drive apparatus with the head in the loaded state with the disk rotating at a first rotational speed, unloading the head, and in Idle Mode, rotating the disk at a second rotational speed lower than the first rotational speed, with the electronics depowered.

Abstract: 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.

Abstract: A magnetic recording system utilizing a plurality of surfaces on a magnetic recording disk with recording zone boundaries established on the respective surfaces of the disk based on performance characteristics of the read/write transducer associated with the surface. The performance of the read/write transducer from the aspects of the width of the track written by the transducers as well as the recording performance at the expected recording frequency, are both utilized in building disk drives. Since the zone boundaries are established uniquely for the performance of each transducer, rather than by defining the boundaries of all zones for all surface in advance based on assumed performance characteristics of the heads, the zone boundaries on one surface of the disk will not necessarily align with the zone boundaries on another surface of the disk. Similarly, when a plurality of disks are utilized, the zone boundaries will not necessarily be aligned.

Abstract: In one embodiment, a rigid disk drive including a rotary actuator having a lift tab extending asymmetrically from the end of the load beam which supports a slider with read/write element is disclosed. The free end of the lift tab cooperates with a cam surface on a cam assembly to provide dynamic loading and unloading of the slider while imparting a roll to the slider as it is loaded to and unloaded from the disk. In another embodiment, the lift tab extends from the end of the load beam along an axis generally parallel to the longitudinal axis of the load beam, but the axis of the lift tab is offset from the longitudinal axis of the load beam. In a further embodiment, a disk drive including a rotary actuator having a load beam which includes a lift tab extending from the free end, with the lift tab cooperating with a cam assembly which is located adjacent to the edge of recording media, but not extending over a surface of the media is provided.

Abstract: An acceleration sensing device senses the acceleration of a computer such that the computer is subject to zero support force (i.e., is in a free fall), and a control microprocessor of the disk drive unit determines that such state lasts for longer than a certain minimum of time. Upon these conditions being met, the control microprocessor signals the removal of the heads from the disk to park the heads.

Abstract: A method of manufacturing a rigid disk drive of the dynamic head loading type which includes a rotary actuator, and a load beam having a lift tab which cooperates with a cam surface of a cam assembly to load and unload a read/write recording element with respect to a surface of a disk. The method includes positioning the left tab so that it extends along an axis which is displaced with respect to a center line of the load beam. The method also includes providing the cam surface with a detent. The method of manufacturing further includes providing a portion of said lift tab with a cylindrical shape.

Abstract: In accordance with this invention, an air bearing slider has a mounting side which has a relieved portion formed by a stepped-contour or a tapered contour. The stepped-contour includes an adherent surface adjacent the rear face of the air bearing slider and a notch surface adjacent the front face of the air bearing slider. The notch surface is closer to the air bearing surface than the adherent surface. The tapered contour includes an adherent surface adjacent the rear face and a taper surface adjacent the front face such that the taper surface is at an angle to the adherent surface. The clearance provided by the relieved portion eliminates interference between the air bearing slider and the load beam surround portions which support the air bearing slider. Depth of the relieved portion of the air bearing slider can be altered easily during grinding for customized multiple drive designs without major retooling effort.

Abstract: A magnetic recording system utilizing a plurality of surfaces on a magnetic recording disk with recording zone boundaries established on the respective surfaces of the disk based on performance characteristics of the read/write transducer associated with the surface. The performance of the read/write transducer from the aspects of the width of the track written by the transducers as well as the recording performance at the expected recording frequency, are both utilized in building disk drives. Since the zone boundaries are established uniquely for the performance of each transducer, rather than by defining the boundaries of all zones for all surfaces in advance based on assumed performance characteristics of the heads, the zone boundaries on one surface of the disk will not necessarily align with the zone boundaries on another surface of the disk. Similarly, when a plurality of disks are utilized, the zone boundaries will not necessarily be aligned.

Abstract: In one embodiment, a rigid disk drive including a rotary actuator having a lift tab extending asymmetrically from the end of the load beam which supports a slider with read/write element is disclosed. The free end of the lift tab cooperates with a cam surface on a cam assembly to provide dynamic loading and unloading of the slider while imparting a roll to the slider as it is loaded to and unloaded from the disk. In another embodiment, the lift tab extends from the end of the load beam along an axis generally parallel to the longitudinal axis of the load beam, but the axis of the lift tab is offset from the longitudinal axis of the load beam. In a further embodiment, a disk drive including a rotary actuator having a load beam which includes a lift tab extending from the free end, with the lift tab cooperating with a cam assembly which is located adjacent to the edge of recording media, but not extending over a surface of the media is provided.

Abstract: 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.

Abstract: In accordance with this invention, an air bearing slider has a mounting side which has a relieved portion formed by a stepped-contour or a tapered contour. The stepped-contour includes an adherent surface adjacent the rear face of the air bearing slider and a notch surface adjacent the front face of the air bearing slider. The notch surface is closer to the air bearing surface than the adherent surface. The tapered contour includes an adherent surface adjacent the rear face and a taper surface adjacent the front face such that the taper surface is at an angle to the adherent surface. The clearance provided by the relieved portion eliminates interference between the air bearing slider and the load beam surround portions which support the air bearing slider. Depth of the relieved portion of the air bearing slider can be altered easily during grinding for customized multiple drive designs without major retooling effort.

Abstract: 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.

Abstract: A magnetic recording system utilizing a magnetic recording disk. In some embodiments, one magnetic surface is utilized with an associated read/write transducer supported by a load beam. In other embodiments, the disk has a plurality of magnetic surfaces, each having an associated read/write transducer for reading and writing data in tracks in a plurality of zones and an associated load beam for supporting and positioning the respective read/write transducer at a plurality of locations above the respective surface. In one embodiment, the radial boundaries of the zones and read/write frequency for each zone are defined as a function of the number of available tracks on the recording surface. In another embodiment, the radial boundaries of the zones and read/write frequency for the zones are defined as a function of the read/write performance of the read/write transducer with respect to its associated magnetic surface.

Abstract: A disk drive with a drive motor having a spindle rotatable around an axis of rotation, one or more disks mounted on the spindle separated by annular spacers which have a radial dimension selected to maintain flatness of the disks, an annular ring dimensioned to distribute force evenly to the disks engaging the last mounted disk, a flat annular spring clamp for applying force uniformly to the annular ring, and a retaining member to hold the annular spring clamp in place.

Abstract: A method of recovering a read/write head in a metastable state employs a retry algorithm which uses a combinatorial approach, i.e., parameters are altered step-by-step, and the retry algorithm is operational for a predetermined time. The method also employs an auxiliary write operation that utilizes a predetermined spare data sector on a track, another sector of which includes data. In this spare data sector, the corrective write/cycling operation can occur without requiring any seek operations and without overwriting of prerecorded data. In addition, the present method may include the step of moving the arm on which the head is mounted to a remote or crash position relative to a magnetic medium such as a disk, and, if so chosen, forcing a write operation with the head in that position.