Abstract: An active damping control for a disk drive includes an i.d. crash stop and an o.d. crash stop which constrain the motion of an actuator arm. Each crash stop includes an inner core manufactured from a material that generates current when mechanically strained. The inner core of each crash stop is connected to a circuit that includes an energy dissipating element that dissipates energy received from either crash stop. Thus, when the actuator arm collides with either crash stop, the rebound of the actuator arm off the crash stop is minimized.

Abstract: A device for monitoring lubricant within a disk drive includes a reservoir packet impregnated with lubricant. The reservoir packet is disposed between a first metal screen and a second metal screen such that a lubricant reservoir transducer is created. The capacitance of the lubricant reservoir packet is monitored and when it falls below a predetermined percentage of the initial capacitance, a user is warned to back up the files contained in the disk drive before failure due to lack of lubricant occurs.

Abstract: A disk drive suspension has a longitudinal axis that defines inner and outer edges of the suspension. A flexure having a head gimbal assembly is aligned with the axis and spring-loaded to the suspension. A single limiter extends from the flexure through an opening in the suspension to hook to the suspension. The limiter limits the planar separation between the flexure and the suspension. The limiter is offset from the axis such that it is located much closer to the inner edge. During the unloading of the suspension from the disk, a tab on the suspension engages a ramp to begin to lift the suspension away from the disk. As the suspension is lifted, the flexure and head gimbal assembly have limited planar separation from the suspension due to the limiter. Since the limiter is offset from the axis, the surface of the head gimbal assembly is skewed relative to the disk.

Abstract: The present invention is a magnetic disk drive for reading or writing magnetically, comprising: (i) a base; (ii) one or more magnetic disks; (iii) a hub fixedly attached to the disk(s) for supporting the disk(s); (iv) a motor operable to rotate the hub; (v) a plurality of magnetic read/write heads, each associated with the surface of a disk; (vi) one or more actuators for supporting the heads and moving the heads across the disks, each actuator having a load/unload tab at its distal end adjacent to the inner diameter side of the actuator; and (vii) a load/unload structure for displacing the heads from the disk comprising a plurality of ramps.

Abstract: A slider used in a disk drive apparatus is described which has an air bearing surface and a trailing surface and a plurality of recessed steps at the trailing edge. These steps at the trailing edge greatly reduce stictional forces.

Abstract: A method for controlling the velocity of an actuator arm in a hard disk drive includes moving the actuator arm to an inner limit or outer limit of motion. Then the power to the actuator coil, which drives the actuator arm, is reduced to zero and the actuator arm is released. Bends in the flexible cable connected to the actuator arm can cause the actuator arm to move toward the outer limit of motion. As the actuator arm moves due to the flexible cable, the velocity contribution of the flexible cable is measured and stored. Thereafter, the velocity of the actuator arm, during emergency power shut off, normal unload of the disk drive, or normal load of the disk drive, is decreased or increased by an amount equal to the cable-induced velocity to compensate for the velocity contribution of the flexible cable.

Abstract: A slider burnishing method is introduced, in which the slider is brought into a predetermined surface contact with the rotating disk for a specified period. The predetermined surface contact and the specified time period are selected together with the surface condition of the rotating hard disk, such that smoothened slider surface is abrasively formed. The smoothened slider surface is substantially parallel to the disk surface and thus provides reduced contact pressure during eventual operational contacting. In addition, the smoothened slider surface creates a constant gap together with the disk surface, which enhances the aerodynamic properties of the air bearing surface and stabilizes a small fly height.

Abstract: A method and apparatus for providing predictive failure analysis using the resistance of a sensor such as a MR, GMR, spin valve or wear sensor. A baseline measurement of resistance for at least one sensor of a disk drive is obtained, subsequent measurements of resistance for the at least one sensor of a disk drive are periodically obtained and the subsequent measurements and the baseline measurement to identify a detrimental change to the at least one sensor are processed. The processing further includes comparing a subsequent resistance measurement for the at least one sensor to the baseline measurement of resistance for the at least one sensor to detect a head/disk interface problem and flagging the file for corrective action when the head/disk interface problem is detected. Alternatively, the processing further includes determining a change in stripe height based upon the difference between the baseline measurement of resistance and the subsequent measurement of resistance.

Abstract: An active bypass circuit for use with a battery pack having a plurality of cells and method of operation thereof. The active bypass circuit includes a first switching device that is series-coupled with a cell in the battery pack (a separate active bypass circuit is utilized for each cell in the battery pack). A second switching device is parallel-coupled across the first switching device and the cell. The first and second switching devices are switched, i.e., turned ON and OFF, in a complementary fashion. The active bypass circuit also includes a monitoring circuit for monitoring an electrical characteristic of the cell and generating a switching control signal, in response to the monitored electrical characteristic, to selectively control the operation of the first and second switching devices. In an advantageous embodiment, the electrical characteristic is a voltage across the cell.

Abstract: A method and apparatus for monitoring the quality of the readback signal of data written on a magnetic recording disk in a disk drive and for limiting data loss due to physical damage at a slider/disk interface. The amplitude of a read signal is continuously monitored in the read channel, either by directly measuring the read signal amplitude or by monitoring the amplification level of the automatic gain control (AGC) circuit in the read channel which is inversely proportional to the read signal amplitude. If the amplitude of the monitored read signal decreases below a chosen level, the location of the data on the disk track is flagged as possibly damaged. The data is rewritten at the same location and then reread to see if full recovery of the degraded data is possible. If the amplitude read signal of the rewritten data is greater than a chosen level, the disk track is judged to be usable and normal operation continues.

Abstract: A hard disk drive contains magnetic disks which are accessed by a series of pivotable arms. Each arm has a pair of flexible, cantilevered suspensions and a head gimbal assembly with a magnetic read/write head secured to each suspension. A tab extends from and forms part of the end of each head gimbal assembly. The hard disk drive also has a stationary cam member located near the outer edges of the disks. The cam member has a series of rigid cantilevered fingers with contoured surfaces. Each surface has three spaced-apart detents with a recess located between each adjacent pair of detents. The second recess on each surface has a lubricant-filled reservoir. For the majority of its operation, the drive pivots the arms between an operational range adjacent to the disks, and a park position in the first recess when the drive is not in use. The tabs slide along the support surfaces of the fingers when the arms move to the retracted position.

Abstract: The present invention provides a method and load/unload structure for implementation in a disk drive, whereby debris is prevented from accumulating on the surface of an air bearing slider by moving the slider ABS across a stationary cleaning pad formed integrally with the ramp structure during loading and unloading. As a first aspect of the invention, space at the disk perimeter is used efficiently by providing a stationary cleaning surface integral to the ramp structure. As another aspect of the invention, cleaning may be enhanced by dithering the slider across the stationary pad, e.g., at selected resonant frequencies, to remove a larger volume of debris. As yet another aspect of the invention, baffling may be provided in the disk drive interior to channel the airflow generated by the disk such that it is directed over the cleaning pad in the direction of an air filter.

Abstract: An arrangement for reducing the stiction bond at power-up time between an slider parked on a disk or other magnetic recording medium. A thermally expansive medium such as alumina is included in the slider body thermally adjacent to the write element. At power-up time or when a failure of the disk, etc. to rotate is detected during startup, a current is applied to the write element. The volume expansion resulting from the heat causes a change in the shape and/or location of the slider surface in contact with the disk and thereby breaks or reduces the slider/disk stiction bond.

Abstract: A data storage system has a disk having a first, second and third zone. The first zone has rough texturing to prevent stiction between a slider at rest and the disk. The second zone has intermediate texturing to prevent stiction when a moving slider is in contact with the disk. The third zone has a smooth texture and is used for data recording. A control unit moves the slider between the zones as appropriate on power up and power down of the system. The system has an actuator latch having a bias device. The bias device allows the slider to be positioned between the first and second zones by selective energizing of the actuator while in the latched position.