Abstract: A method is used for moving a transducing head between tracks of a disc in a dual-stage actuation assembly. The dual-stage actuation assembly has a main actuator for coarse positioning of the transducing head and a microactuator for fine positioning of the transducing head. The method comprises accelerating the main actuator during coarse positioning of the transducing head and applying control pulses to the microactuator during coarse positioning by the main actuator to eliminate oscillation of the microactuator during and after coarse positioning.

Abstract: A load balancing circuit which operates to balance the output voltages of a dual polarity power supply with single polarity voltage regulation. The power supply outputs a positive voltage at a positive voltage with respect to a reference level and a negative voltage with respect to the reference level. The power supply further applies voltage regulation to a selected one of the positive and negative voltages and leaves the remaining one of the positive and negative voltages in an unregulated state. Positive and negative loads are coupled to receive the positive and negative voltages. The load balancing circuit detects a change in impedance of a selected one of the positive and negative loads and applies a corresponding impedance to the power supply to maintain the power supply in a nominally balanced state.

Abstract: A perpendicular magnetic recording medium includes a hard magnetic recording layer and a soft magnetic underlayer adjacent the hard magnetic recording layer. The soft magnetic underlayer includes first and second ferromagnetically coupled multilayer structures and a coupling layer positioned between the first and second multilayer structures for antiferromagnetically coupling the first and second multilayer structures. A magnetic disc drive storage system incorporating such a perpendicular magnetic recording medium and a method of making such a perpendicular magnetic recording medium are also included.

Abstract: A low noise, high areal recording density, perpendicular magnetic recording medium comprises: (a) a non-magnetic substrate having a surface; and (b) a layer stack formed over the substrate surface, the layer stack comprising, in overlying sequence from the substrate surface: (i) a magnetically soft underlayer; (ii) at least one non-magnetic interlayer; and (iii) a CoCr-based, magnetically hard perpendicular recording layer; wherein the compositions of the at least one non-magnetic interlayer and the CoCr-based, magnetically hard perpendicular recording layer are selected to provide the medium with a negative nucleation field Hn, remanent squareness of about 1, and high coercivity of at least about 5,000 Oe. A method for manufacturing the medium by means of DC magnetron sputtering of layers (i)-(iii) is also disclosed.

Abstract: A magnetic head for use in magnetic data storage systems is provided. The magnetic head includes a substantially non-magnetic writer gap layer and pair of magnetic poles separated by the writer gap layer. A first of the poles includes a first layer formed of a CoNiFe alloy that has a saturation magnetic moment greater than 2.1 Tesla. Methods of fabricating such a head are also disclosed.

Abstract: According to one embodiment of the present invention, a method of counteracting gas ingestion in a hydrodynamic bearing of a spindle motor in a data storage device comprises waiting for activity of a host connected with the data storage device to become idle. When the activity of the host becomes idle, a determination is made whether to release gas from a fluid of the hydrodynamic bearing of the spindle motor. Responsive to determining to release gas from a fluid of the hydrodynamic bearing of the spindle motor a motor spin down routine for the spindle motor is performed.

Abstract: To simplify fabrication of an integral hub piece, the opening between the upper and lower female cones in this hub has sufficient width or radial dimension to allow access to both cones from one side of the hub with the cutting tool. A cutting tool is used which has a width smaller than the opening between the cones. Preferably, the tool has a width which is about equal to or smaller than an angular dimension through this opening which is defined by extending surfaces of the upper and lower female cones. If this limitation is satisfied, both cones can be created with a single machine set up operating from one side of the integrated hub.

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: A method for detaching a suspension assembly adapted to support a head staked to an actuator arm of an actuator block of a disc drive. The method includes the steps of inserting an expandable device having an expandable flanged end, expanding a dimension of the inserted flanged end and moving the device to release the suspension assembly staked to the actuator arm.

Abstract: The present invention provides for the enhancement of the storage capacity of a data disk drive while reducing optical path optics, electronics and/or the mass and complexity of associated read/write heads. The system utilizes light transmitted by optical elements to servo track a data disk and to heat the data disk during reading and writing of data, and magnetic elements for actual reading and writing.

Abstract: It is generally believed that, the more pure the servo pattern timing reference, the better. A system writes a servo clock track on a disc in a disc drive. The clock track is written on the disc and the servo system is configured to reduce a splice error in a timing signal based on the clock track. The system is also configured to reduce phase-locked oscillator (PLO) jitter in the timing signal. In one embodiment, the splice error and PLO jitter are both measured using a single phase measurement circuit.

Abstract: Method and apparatus for improving data transfer rate performance of a disc drive data handling system having a plurality of transducing heads adjacent a corresponding plurality of data recording surfaces. Concentric tracks on each of the recording surfaces are provided with a physical track address determined by servo data written to each track. Logical track addresses are assigned to the tracks by positioning a first head adjacent a selected location on the corresponding recording surface, measuring a head offset value for each of the remaining heads, and assigning the logical track addresses on each data recording surface in relation to the measured head offset values. The logical cylinders include tracks with different physical track addresses, and the tracks in each logical cylinder are nominally aligned with the heads. This reduces the need for corrective seeks after head switching within the same logical cylinder.

Abstract: A slider for use in a disc drive system that is comprised of a trailing edge, a connection for applying a voltage to the slider, an actuation surface for providing electrostatic control, and a recessed area between the trailing edge and the actuation surface. Applying voltage to the slider provides a method for controlling fly height between the trailing edge of the slider and the disc.

Abstract: A vertically-oriented servo track writer assembly and method for recording servo pattern on a disc surface includes a spindle hub assembly that rotates one or more discs in a substantially vertical plane and an actuator assembly that pivots an E-block about a substantially horizontal axis. The E-block includes one or more actuator arms and associated flexures, with each flexure including a servo recording head. Pivoting motion of the E-block moves each servo recording head in a substantially vertical plane adjacent a surface of an associated disc to record servo pattern information on the disc surface. The method further includes laterally moving the actuator assembly into and out of engagement with the spindle hub assembly to simplify loading and unloading discs from the spindle hub assembly.

Abstract: A magnetic head for reading information from a magnetic medium is provided. The magnetic head includes a substrate, having a substrate thermal coefficient of expansion, and a read element positioned above the substrate. The head also includes a shield, positioned above the substrate and adjacent the read element, which has a shield thermal coefficient of expansion that substantially matches the substrate thermal coefficient of expansion. The shield absorbs stray magnetic fields from the magnetic medium, which emanate from stored data that is adjacent to a data element that is directly beneath and read by the magnetoresistive read element. This shield may also serve to provide electrical contact for the read element. The magnetic thermal coefficient of expansion and electrical properties of the shield may be suitably optimized through appropriate choice of component materials and structure.

Abstract: A thin film magnetic recording medium, comprising: at least one ferromagnetic thin film recording layer comprising magnetic particles with substantially uniform barriers to magnetization reversal, formed by a process comprising steps of: (a) providing a precursor structure including at least one ferromagnetic thin film recording layer having a surface and a first, higher coercivity which may be greater than that which permits writing of the precursor structure, comprising magnetic particles having a distribution of energy barriers to magnetization reversal; and (b) uniformly bombarding the entire surface of the precursor structure with particles of sufficient dosage and energy to: (i) substantially equalize the energy barriers to magnetization reversal of the magnetic particles; (ii) lower the coercivity of the at least one ferromagnetic thin film recording layer from the first, higher coercivity to a second, lower coercivity within a range of coercivities permitting writing of the bombarded at least one

Abstract: A magnetic recording head includes a zero throat formed on a bottom pole layer and a dielectric layer formed over a portion of the bottom pole layer and over a portion of the zero throat. A bottom pole extension, a gap layer, and a top pole extension are plated in a pole tip region of the recording head so that the dielectric layer separates the plated layers in the pole tip region from the zero throat. The dielectric layer reduces the magnetic flux leakage between a bottom pole extension and a top pole extension of the recording head.

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: One embodiment of the present invention pertains to a slider that includes an aerodynamic surface which includes a first bearing surface, a cavity floor, and a first recessed pressurization surface. The first bearing surface is disposed on the aerodynamic surface, defining a bearing height. The cavity floor is disposed on the aerodynamic surface at a cavity depth below the bearing height. The first recessed pressurization surface is adapted to provide above-ambient fluid pressure when the slider is in nominal flight, which is greater than fluid pressure provided elsewhere on a trailing half of the aerodynamic surface at a substantial displacement from a longitudinal centerline of the aerodynamic surface. The first recessed pressurization surface is disposed on the aerodynamic surface at a recessed depth which is between the bearing height and the cavity depth.

Abstract: The invention provides a magnetic sensor having a first opposing pair and a second opposing pair of resistive elements configured in a Wheatstone bridge, wherein the resistive elements are a synthetic antiferromagnetic giant magnetoresistive sensor having a reference layer and a pinned layer of different thicknesses, wherein the first opposing pair has a net magnetic moment that is opposite to that of the second opposing pair, and wherein the first opposing pair has a thicker reference layer than pinned layer, and the second opposing pair has a thicker pinned layer than reference layer. Other embodiments of the invention have resistive elements that are opposingly bilayer and trilayer synthetic antiferromagnetic giant magnetoresistive sensors, or opposingly synthetic and standard antiferromagnetic giant magnetoresistive sensors.