Abstract: An actuator assembly includes a rotatable actuator arm mounted on the base of a disc drive. The actuator arm includes a metallic member seated on a non-metallic body. A proximal end of a load beam is mounted on the actuator arm and a distal end of the load beam supports a head. The actuator assembly also includes a connection between the metallic member and the load beam that secures the load beam to the actuator arm.

Abstract: An actuator retract system and method for moving read/write heads from data regions on discs to non-data locations in a disc drive is disclosed. The non-data locations may be on or in close proximity to the discs. The non-data locations may be a landing zone or a load/unload ramp. At disc drive power-down, power generated from the rotational inertia in rotating discs is used to supply a current to a coil of a voice coil motor operably coupled to the actuator. During such power-down operation, a desired velocity is maintained using acceleration or deceleration, when necessary. The current generates an electric field around the coil that interacts with a magnetic field in the voice coil motor to move the actuator such that the read/write heads are retracted to the non-data location.

Abstract: A disc drive having a pivot cartridge and an actuator assembly. The actuator assembly consists of an actuator body which has a bore therein to receive the pivot cartridge. The actuator body further consists of an opening which serves as a ledge to engage a biased retaining ring. The biased retaining ring couples onto the pivot cartridge and forces the pivot cartridge to contact against one side of the bore of the actuator body.

Abstract: Packaged surface mount (SMT) chips having matched top contacts and bottom contacts are stacked. Chip features are selected to provide the desired connectivity between chip layers with a greater ease of manufacture. In one embodiment, additional spacing and routing layers are optionally provided between layers. In another, chips are differentiated by optionally providing different conductor and/or nonvolatile cell configurations. In yet another, a minority of a substrate's contacts are configured for aligning with a dielectric region of a spacing layer or substrate to create very low capacitance signal paths between stacked chips.

Abstract: A method of handling resonance effects on disc drives includes the steps of monitoring a position error signal (PES) for an actuator arm of a disc drive, generating a feedforward compensation signal from the PES using a bandpass filter, and applying the compensation signal to a servo control signal. The bandpass filter has a center frequency set to a known resonance frequency. A disc drive includes an actuator assembly including an arm for carrying a head in a transducing relation with respect to a disc in response to a control signal, and a controller that monitors a PES for the arm and generates the control signal. The controller includes a servo controller that generates a servo control signal from the PES, and a feedforward compensation element which bandpass filters the PES to generate a compensation signal which is combined with the servo control signal to generate the control signal.

Abstract: An actuator stop for a disc drive having a compliant suspension member joining a rigidly supported stop pin and a noncompliant contact member. The contact member is characterized by a relatively greater compressive yield strength than that of the suspension member so that in response to an abutting engagement with the actuator. The contact member is displaceable relative to the stop pin in relation to the deflection characteristics of the suspension member.

Abstract: A disc drive, includes a base, a disc stack rotatably attached to the base, and an actuator assembly movably attached to the base. The actuator assembly includes an E-block. The E-block for a disc drive includes a metal core and a ceramic coating on the metal core of the E-block. The ceramic coating on the metal core of the E-block is less dense than the metal core. The stiffness of the ceramic coating on the metal core of the E-block is greater than the stiffness of the metal core. In one embodiment, the E-block has a metal core of aluminum. The ceramic coating is may be formed using any method, including an electrochemical process or by depositing the ceramic coating onto the E-block.

Abstract: A pivot cartridge assembly with improved resonance characteristics. One end of the pivot bearing shaft is mounted to the base of the disc drive, and the other end is secured to the cover of the disc drive in such a manner that the resonance characteristics of the pivot bearing assembly is improved in both the axial and radial direction of the pivot bearing shaft.

Abstract: A transducer position sensing system in a disc drive to take frequent data measurements from micro-servo sectors on the disc and to interpret the information to predict recording failures. The disc drive is formatted with many small or micro-servo sectors containing, among other things, a servo address mark, encoded disc location information, and radial track position information. The sensing system frequently retrieves this information through the transducer, compares the measurements to expected values, and given unexpected measurements predicts errors. The time elapsed between the passing of servo address marks can be used to predict adjacent sector overwrites. The radial track position information can be used to predict off-track write errors. The radial track position signal amplitude can be used to predict the transducer moving too far from the disc, resulting in skip write errors.

Abstract: A data storage device control module for controlling operational processes in a data storage device comprises a number of preemptive modules, a number of non-preemptive modules, and a scheduler module operable to schedule the execution of the non-preemptive modules only in the data storage device control module. Preferably included as one of the non-preemptive modules is a queue processor module operable to manage the position and movement of command nodes in multiple command node queues.

Abstract: The present invention offers a time efficient means to determine and eliminate dynamic track squeeze error. The present invention can be used to correct imperfections in tracks written by a conventional servowriter or using self-propagating servo writing. The dynamic track squeeze is determined within a single disc revolution. The read head is positioned half way between two servo tracks. Positioning information for track following is obtained from either track as one disc revolution is completed. During the disc revolution, position measurement is simultaneously collected from both tracks. The difference between the position measurements from each track, which represents the dynamic track squeeze between the two tracks, is determined. An appropriate ZAP correction factor is determined and written to the servo sector of the desired track. The ZAP correction factor is input to the disc drive servo controller and eliminates the dynamic track squeeze.

Abstract: In a disc drive, a voice coil motor is configured to drive an actuator with mainly torque, thereby reducing unwanted vibration of the actuator. The voice coil motor includes a moving coil vertically disposed with respect to a horizontal radial magnetic field provided by a stationary unipolar magnet such that the active portions of the coil are of different radial separation from the actuator pivot. A yoke facilitates closure of the magnetic flux paths.

Abstract: There is provided a pre-amplifier with a baseplate configured for mounting to an actuator in a disc drive. The baseplate is directly fixed to the actuator at one point, with a damping layer between a second surface of the baseplate and the actuator. The damping layer helps to constrain the baseplate from rotational movement relative to the actuator. Preferably, the baseplate is fixed to the actuator by a grounding pin coupled to the baseplate.

Abstract: An actuator assembly of a disc drive having an actuator arm rotatably mounted adjacent a data disc. The actuator arm has a top surface and a bottom surface, and includes a head gimbal assembly support portion located at one end of the actuator arm. The actuator assembly further includes an arm circuit fastened to the top surface of the actuator arm. The actuator assembly may additionally include a head gimbal assembly that electrically couples the data transducer and the arm circuit. The gimbal circuit is partially routed along the head gimbal assembly and over the top surface of the actuator arm. Alignment apertures on the arm circuit and the head gimbal circuit and alignment pins on the actuator arm may be used for positioning of the circuits over the top surface of the actuator arm.

Abstract: A method and apparatus for controlling acoustic noise generated by a seek operation in a disc drive by using a feedback control system to control the seek operation. The feedback control system is excited by a feed-forward signal during execution of the seek operation. An acoustic factor, which defines a seek operation noise level, is selected. The feed-forward signal is generated based, at least in part, upon the selected acoustic factor. The feed-forward signal has a first derivative having a maximum value. The selected acoustic factor is used to select the maximum value of the first derivative of the feed-forward signal.

Abstract: A method and system for managing the transfer of data into and out of a buffer in a disc drive is disclosed. The operation of the vectored buffer management (VBM) system is administered by a software-based control module. The control module creates and maintains a buffer table by dividing the buffer table into buffer sectors. The buffer sectors are further arranged into buffer segments, or circularly linked lists upon which the buffer table is partitioned. The control module effectuates the transfer by implementing an application module across the buffer table. Once the application module is arbitrarily positioned at an index sector by the control module, data transfer is accomplished when the application module walks through a particular buffer segment identified by the index sector. Specific control of the application module across a buffer segment is administered through host and disc address pointers, which are coupled to host and disc next pointers, respectively.

Abstract: An information handling system, such as a disc drive, includes a base, a disc stack rotatably attached to the base, and an actuator assembly movably attached to the base. A region of the disc stack is identified as a parking band, and when power is not provided to the disc drive, the actuator assembly is held in a parked position within the parking band by an actuator latch. The actuator latch and actuator assembly have different resonant frequencies based on several environmental elements near the actuator assembly, including the temperature of the environment in the disc enclosure. The actuator assembly is unlatched by measuring the environmental element near the actuator assembly and applying an alternating current to a voice coil coupled to the actuator. The frequency of the alternating current applied to the actuator assembly during the unlatching procedure is near the resonant frequency of the actuator assembly in the measured environment.

Abstract: The sleeve of an actuator bearing cartridge is provided with an inclined surface on its outer surface. A tolerance ring is placed around the sleeve, and the cartridge and ring are then press-fit into the actuator bore together. Axial slippage of the ring and actuator relative to the cartridge is prevented as the ring is effectively wedged between the inclined surface and the inner surface of the actuator bore.

Abstract: Methods and systems in a data storage device selectively employ a seek time array and/or a seek time list to accurately predict a time required for a seek operation to move a transducer in the data storage device a given seek distance. The seek time list and/or seek time profiles are automatically compiled in the data storage device based on seek time entries located in a servo data table located in the data storage device.

Abstract: The temperature of an actuator voice coil in a disc drive is regulated so as to prevent outgassing. In a preferred embodiment, coil temperature is calculated at the beginning of each long seek. If the temperature is determined to be at or below a predetermined “safe” level, temperature rise is not limited and power may be applied to the coil without additional limitations. If, however, coil temperature is determined to be above the “safe” level, proportional control is used to scale back power generation so as to prevent the coil temperature from exceeding the coil's specified temperature limit.