Abstract: A magnetoresistive sensor for sensing a magnetic storage medium includes a free layer that has a magnetic anisotropy that supports stable magnetic states. A magnetic field generator biases the stable states of the free layer. The magnetic field generator may permanently bias the free layer through the use of permanent magnets or may intermittently bias the free layer with a magnetic field generated by an alternating current. A magnetic storage medium is located proximate to the magnetoresistive sensor. The magnetoresistive sensor switches between stable magnetic states in response to the data on the magnetic storage medium. The magnetoresistive sensor senses the data stored in sectors on a magnetic medium by magnetically biasing the free layer, positioning the sensor proximate to a sector of the magnetic medium to be sensed, removing the magnetic bias and then sensing the magnetic state of the free layer while the magnetic bias is removed.

Abstract: A method of manufacturing a magnetic recording medium, comprises steps of providing a non-magnetic substrate for a magnetic medium, the substrate including at least one major surface having a contact start/stop (CSS) or landing zone and a data zone; and forming a pattern of recesses in the substrate surface in said CSS or landing zone by embossing utilizing a stamper having a surface including a negative image pattern of said pattern of recesses. Embodiments of the invention include magnetic media comprising a non-magnetic substrate including at least one major surface having a contact start/stop (CSS) or landing zone and a data zone, said substrate surface in said CSS or landing zone comprising an embossed pattern of recesses. In addition, the data zone of the substrate surface may include an embossed servo pattern formed simultaneously with the embossed pattern of recesses formed in the landing zone.

Abstract: A method of manufacturing a magnetic recording medium comprises steps of providing a non-magnetic substrate for a magnetic recording medium, the substrate including at least one major surface; forming a layer of a sol-gel on the at least one major surface; forming a pattern, e.g., a servo pattern in an exposed surface of the layer of said sol-gel; and converting the layer of sol-gel to a glass or glass-like layer while preserving the pattern in an exposed surface of said glass or glass-like layer. Embodiments of the invention include magnetic media including a patterned glass or glass-like layer formed from a layer of a hydrophilic sol-gel with the pattern embossed therein by means of a stamper having a hydrophilic surface including a negative image of the pattern.

Abstract: A disc drive slider test system includes a support structure and a slider test socket carried by the support structure that releasably electrically and mechanically receives a slider for testing. The slider test socket includes a body forming a cavity for receiving the slider and a plurality of spring beams outside a plan area of the body connected to a clamp for releasably securing the slider in the cavity. In some exemplary embodiments, a microactuator is employed to position the slider secured by the slider test socket with high resolution with respect to tracks of the disc.

Abstract: A method of improving the robustness of microcomponents formed of silicon by armor coating the microcomponent with a ductile material, such as a metal. The armored coating may comprise either partial armored coating or total armored coating. Providing the microcomponent with an armored coating reduces chipping and breaking, and likewise reduces contamination problems which arise from chips and breaks.

Abstract: Method and apparatus for accessing a block data storage device through a computer network to carry out remote diagnostic operations. The data storage device includes a data storage medium, a host interface port, a serial communication (COM) port and a programmable controller with associated platform firmware and associated diagnostic firmware. A client computer and a server computer are connected to a computer network, and the data storage device is connected to the server computer via the host interface port. The server computer is used to transmit a first command to cause the controller to execute the platform firmware, while the client computer is used to transmit a second command to the COM port of the data storage device to cause the controller to concurrently execute the diagnostic firmware to monitor operation of the platform firmware.

Abstract: Method and apparatus for accelerating a disc drive spindle motor to an operational velocity at which data are transferred between a host device and a disc rotated by the spindle motor. The spindle motor is initially accelerated from rest to an intermediate velocity at which sufficient back electromotive force (bemf) is generated by the rotation of the spindle motor to enable commutation circuitry of the disc drive to time the application of drive pulses to the spindle motor. The spindle motor is subsequently accelerated from the intermediate velocity to the operational velocity by applying a velocity dependent reference profile which establishes a sequence of reference levels to control the flow of current through the spindle motor during acceleration. The sequence of reference levels have different magnitudes at different velocities of the spindle motor between the intermediate velocity and the operational velocity.

Abstract: A filter for attenuating a resonance mode without substantial phase margin loss. The filter comprises a transfer function having an additional pole, such that the phase of the input signal is advanced. The phase-advanced filter substantially attenuates all frequencies above a selected center frequency while avoiding substantial phase margin loss.

Abstract: A system and method of verifying data transferred along a data path from one buffer, such as a user buffer in the host system to a second buffer, such as a disc drive buffer on a disc drive system by using the receiving device to test the information and provide a confirmation or error signal to the sending device. The system and method appends non-abstract identification tags to the abstract data in the first buffer, i.e., the data to be stored to and/or read from the storage device. The tags are transmitted along with the abstract data and provide unique information that is used by either the disc drive device or the host system to validate data received from the other. The validation is based on a comparison of the tag values to a predetermined control value that may be received prior to receiving the abstract data.

Abstract: A disc head slider includes a slider body having a disc-facing surface, a recessed area positioned on the disc-facing surface, and a raised rail positioned on the disc-facing surface adjacent the recessed area. The raised rail includes a bearing surface and a recessed step surface which is recessed from the bearing surface and is raised from the recessed area. A plurality of bearing pads are formed on the recessed step surface and have upper surfaces that together define the bearing surface. A non-bearing pad is formed on the recessed step surface and has an upper surface, which is generally coplanar with the bearing surface, and a pointed leading pad edge.

Abstract: The present invention is directed to a ramp load disc drive storage system having improved loading performance and a reduced likelihood of failure due to stiction and damage caused by contact between a slider and a disc surface during ramp load operations. The slider generally includes wear-resistive pads which allow for improved loading performance and reduce stiction between the slider and a disc surface. The pads also allow the ramp load disc drive storage system to be operated in a ramp load/unload mode or a contact start/stop mode. Additionally, a method of operating a ramp load disc drive is provided where the slider is loaded above a disc surface from a ramp prior to the disc reaching a full operating speed.

Abstract: A read/write head includes a bottom shield and a shared shield. The shared shield includes a first domain and a plurality of closure domains. The read/write head also includes a magnetoresistive sensor deposited adjacent an air bearing surface between the bottom shield and the shared shield. The magnetoresistive sensor includes a magnetoresistor aligned with the first domain. Non-magnetic material separates the magnetoresistive sensor from the bottom shield and the shared shield. The shared shield includes a shaped feature that defines an unambiguous direction of magnetization for the first domain.

Abstract: A stabilized GMR device includes a GMR stack having a first and a second edge. Stabilization means are positioned adjacent to the first and the second edge of the GMR stack for stabilizing the GMR stack. The GMR stack includes a first layer of ferromagnetic material and a second layer of ferromagnetic material. A spacer layer is positioned between the first and the second ferromagnetic layers. A buffer layer is positioned adjacent to the first magnetic layer and a cap layer is positioned adjacent to the second ferromagnetic layer. The stabilization means include a first coupler layer positioned adjacent to the first edge of the GMR stack and a second coupler layer positioned adjacent to the second edge of the GMR stack. The stabilization means also include a first ferromagnetic layer positioned adjacent to the first coupler layer and a second ferromagnetic layer positioned adjacent to the second coupler layer.

Abstract: An air current diverting apparatus for a data storage device having a rotating data storage medium in operable relation with an actuator assembly reading data from and writing data to the data storage medium. The air current diverting apparatus has an aerodynamic shroud comprising a base having a first end attachable to the actuator assembly, an upstream surface extending upstream of the actuator assembly, and a downstream surface extending downstream of the actuator assembly and substantially non-parallel to the upstream surface.

Abstract: A method of manufacturing a magnetic recording medium comprises steps of providing a non-magnetic substrate for a magnetic recording medium, the substrate including at least one major surface; forming a layer of a sol-gel on the at least one major surface; forming a pattern, e.g., a servo pattern in an exposed surface of the layer of said sol-gel; and converting the layer of sol-gel to a glass or glass-like layer while preserving the pattern in an exposed surface of said glass or glass-like layer. Embodiments of the invention include magnetic media including a patterned glass or glass-like layer formed from a layer of a hydrophilic sol-gel with the pattern embossed therein by means of a stamper having a hydrophilic surface including a negative image of the pattern.

Abstract: A data transducer is used for writing data to a disc and has an air bearing surface. The data transducer also includes a bottom pole and a top pole separated from the bottom pole at the air bearing surface by a write gap. A core is formed between the bottom pole and the top pole and a conductive coil is positioned within the core. The data transducer further includes means for dissipating thennal energy away from the coil.

Abstract: A method of manufacturing a magnetic recording medium, comprises steps of providing a non-magnetic substrate for a magnetic medium, the substrate including at least one major surface having a contact start/stop (CSS) or landing zone and a data zone; and forming a pattern of recesses in the substrate surface in said CSS or landing zone by embossing utilizing a stamper having a surface including a negative image pattern of said pattern of recesses. Embodiments of the invention include magnetic media comprising a non-magnetic substrate including at least one major surface having a contact start/stop (CSS) or landing zone and a data zone, said substrate surface in said CSS or landing zone comprising an embossed pattern of recesses. In addition, the data zone of the substrate surface may include an embossed servo pattern formed simultaneously with the embossed pattern of recesses formed in the landing zone.

Abstract: An apparatus and method for writing servo data to a rotatable disc of a disc drive, the servo data used to control the position of a read/write head adjacent the disc. An internally mounted clock head assembly provides disc angular position information by writing and subsequently reading a clock pattern to and from the disc. A radial position detection assembly identifies the radial position of the head. A control circuit controls the function and position of the head to write the servo data to the disc in response to the disc angular and head radial position information. The clock head assembly and radial position detection assembly remain contained within the disc drive during subsequent field use, and can be configured to detect the application of rotational vibration to the disc drive and to rewrite the servo data.

Abstract: A balancing system for a spindle assembly for compensating for dynamic imbalance of the spindle assembly. The spindle assembly includes a rotor rotatable about a shaft. The rotor includes a plurality of radially concentric channels supporting adjustable eccentric rings for dynamically balancing the spindle assembly. The spindle assembly is balanced by adjusting the balanced of eccentric rings assembled with the spindle assembly based upon a measured balance of the spindle assembly and the eccentric rings.

Abstract: Method and apparatus for controlling a motor. A digital to analog converter (DAC) converts input digital values to corresponding analog voltages over a range of different selectable dynamic operating ranges. A first motor adjustment signal within a first dynamic range of the DAC is generated in relation to a velocity error of the motor, and applied to the DAC to control flow of current through the motor. The DAC is adjusted to a different, second dynamic range when the first motor adjustment signal is proximate an upper end or a lower end of the first dynamic range. Expanding the dynamic range allows greater amounts of current to be applied to the motor; contracting the dynamic range provides higher resolution (volts/count) and greater stability. The different ranges are automatically selected for different motor load conditions.