Abstract: A method and apparatus for aligning and securing a spindle shaft and actuator shaft in a low-density gas-filled hard disk drive and independent of the disk drive cover is provided. A capture plate is positioned above the memory disk(s) and is secured to the base plate. The spindle shaft and, optionally, the actuator shaft are secured between the base plate and capture plate. The capture plate may be configured to reduce vibration. This structure eliminates use of the cover to secure the spindle shaft and actuator shaft and, thereby, eliminates a potential pathway for low-density gas to escape. The capture plate may also be configured to reduce air turbulence created by the rotating disk and reduce track misregistration of the read/write element(s).

Abstract: The present invention is directed to a load/unload disk drive that includes: a rotational arm engaging a slider; a magnetic storage disk, wherein the magnetic head in the slider reads data from and/or writes data to a data zone of the magnetic storage disk; and a ramp positioned next to the magnetic storage disk. The magnetic storage disk includes a slider cleaning zone having a roughness greater than a roughness of the data zone. The slider is periodically contacted with the slider cleaning zone to remove particles collected on the slider.

Abstract: A disk drive includes a rotatable data storage disk, and head, a controller, and a preamplifier. The head is configured to write data to and read data from the disk. The controller is configured to generate a write current command. The preamplifier includes a plurality of write current parameters, and is configured to select among the plurality of write current parameters based on the write current command from the controller, and to generate a write current having a shape that varies based on which of the write current parameters are selected. The write current is provided to the head to write a plurality of data bits on the disk.

Abstract: Compositions and materials for use in load/unload ramps in magnetic disk drive assemblies are disclosed, particularly compositions or materials to improve at least one of the desired characteristics of low wear, low cost, high mechanical stability and high moldability. Thermoplastic polymers, such as acetal homopolymers, acetal copolymers, polyetherimides, polyphenylene sulfides, and polysulfones, are combined with other compositions, such as polyaramides, to improve the characteristics of a load/unload ramp constructed therefrom. Additionally, another material may be added, such as a polytetrafluoroethylene or perfluoropolyether.

Abstract: A circuit assembly for mounting one or more integrated circuits that effectively dissipates heat generated by the integrated circuits, and a corresponding method for fabricating such a circuit assembly. The circuit assembly comprises a substrate, a thermally-conductive adhesive layer and a heat-dissipating layer. The substrate includes an opening extending between a first surface and a second surface of the substrate. An integrated circuit is to be mounted on the first surface of the substrate substantially coincident with the opening. The thermally-conductive adhesive layer is at least partially disposed within the opening in the substrate. The heat-dissipating layer is disposed on the second surface of the substrate and includes a raised portion that at least partially extends through the opening in the substrate.

Abstract: Data recovery, following a read error in a hard disk drive, is provided which includes an adjustment of fly height. In one embodiment, some re-reads are performed by both adjusting the fly height and the off-track positioning of the read head. In one embodiment, two or more fly heights are normally used during read/write operations such as in a zoned manner, and adjustments to fly heights are performed with respect to the fly height for the zone where the error occurred.

Abstract: A disk drive selects seek speed and seek acoustics based on a history of seek requests from a host computer. The history of seek requests can include time intervals between seek requests, seek lengths of seek requests, locations of seek requests, a backlog of seek requests, whether seek requests are read requests or write requests, and whether seek requests are sequential or random.

Abstract: A method is provided for identifying offsets of accelerometers integrated into hard disk drives. More specifically, often, disk drives employ accelerometers that constantly monitor the acceleration felt by the disk drive. Once the accelerations are less than a predetermined threshold, a free fall event is identified and an actuator arm that is generally positioned above the disk is placed in a safe location prior to impact. Accelerometers must be calibrated prior to use such that their inherent errors are identified and factored into the algorithm that identifies free fall. The method provided herein allows for the 0 g offset to be monitored without having to reorient the device being tested, thus saving time and money.

Abstract: A disk drive includes a rotatable data storage disk, a transducer, an actuator, and a controller. The transducer is configured to read and write data on the disk. The actuator is configured to position the transducer relative to defined portions of the disk. The controller is configured to determine how many times data has been written to the defined portions of the disk. The controller is also configured to refresh data residing at a particular one of the defined portions of the disk when the number of times data has been written to the particular defined portion of the disk satisfies a threshold value.

Abstract: A system that produces one or more non-repeating randomizer sequences of up to 2m?1 or more m-bit symbols includes a randomizer circuit that is set up in accordance with a polynomial with primitive elements of GF(2m) as coefficients. The system combines the randomizer sequence with all the symbols of ECC code words that are encoded using a BCH code over GF(2m) to produce a randomized code word. The particular primitive elements used and/or an initial state of one or more registers in the system specifies the particular sequence produced by the system. The initial state of each of the one or more registers is a selected one of the 2m?1 elements of GF(2m), and thus, 2m?1 different sequences may be produced by selecting a different initial state for a given one of the registers. If the coefficients are also selected from, for example, a set of “p” possible values, the system produces p*(2m?1) different sequences.

Abstract: In some embodiments of the present invention, a disk drive includes a rotatable data storage disk, a head, and a controller. The head is configured to fly on an air cushion relative to a data recording surface of the rotating disk while writing data to the data recording surface responsive to a write command from a host device or while reading data from the data recording surface to generate a read signal responsive to a read command from the host device. The controller is configured to measure flying height of the head relative to the data recording surface of the disk in response to sensing power-up of the disk drive and/or a shut-down command from the host device. The controller may measure the flying height in response to sensing power-up of the disk drive and, subsequent to measuring the flying height, may generate a ready signal to the host computer that indicates that the disk drive has powered-up and is ready to receive read/write commands from the host computer.

Abstract: A disk drive includes a rotatable data storage disk, a transducer, an actuator, and a servo burst demodulator. The rotatable data storage disk includes a plurality of servo burst patterns thereon. The plurality of servo burst patterns are substantially radially aligned to each other, and radially adjacent ones of the servo burst patterns are configured to generate contributions to a read signal that are substantially orthogonal to each other. The transducer is configured to read the servo burst patterns on the disk to generate the read signal. The actuator is configured to position the transducer relative to the disk. The servo burst demodulator is configured to identify a separate contribution to the read signal from the radially adjacent servo burst patterns. The servo burst demodulator may be configured to generate transducer position information based on the identified separate contribution to the read signal from the radially adjacent servo burst patterns.

Abstract: A system which includes a disk drive or other storage device coupled to a host system provides for reduction of the amount or rate of drive power consumption using procedures which are at least partially executed on the host. The system can be configured to reduce average power draw, maximum power draw, or both. Host-based procedures can be tailored to specific and/or changing environments and can decrease some or all expenses associated with previous attempts to reduce HDD power consumption.

Abstract: In accordance with various embodiments, initial servo data are written to a storage medium as a series of radially overlapped spiral segments. Final servo data are thereafter written to the medium while concurrently servoing on said overlapped segments.

Abstract: In accordance with various embodiments, a rotatable member is mounted to a spindle hub so that initial servo data previously provided to the rotatable member are eccentrically offset with respect to a rotational center of the spindle hub. Compensation vales are determined to characterize said offset, after which final servo data are provided to the rotatable member in relation to the initial servo data and the determined compensation values. The final servo data are nominally concentric with the rotational center of the spindle hub.

Abstract: Preferred embodiments of the present invention are generally directed to reducing variation in a distribution of transducer fly heights by selectively applying first and second fly height adjustment values to a plurality of transducers, the second fly height adjustment value being a multiple of the first fly height adjustment value.

Abstract: A driver for a voice coil motor in a disk drive includes a sensor that provides a sense current by sensing a coil current in the voice coil motor, a comparator that provides an error current by determining a difference between a command current and the sense current, an integrator that provides an integrated error current by integrating the error current, and an amplifier that provides the coil current by amplifying the integrated error current.

Abstract: A disk drive having a drive housing, a storage disk that is rotatably coupled to the drive housing, and a slider assembly that includes a head and a slider mover. The head reads data from the storage disk during a read operation and writes data to the storage disk during a write operation. The slider mover maintains the head at a read HtD spacing during the read operation, at a pre-write HtD spacing during the read operation prior to the write operation, at a write HtD spacing during the write operation, and at an idle HtD spacing when the drive is not performing the read operation or the write operation. The disk drive includes a drive circuitry that directs a read power level to the slider mover to maintain the head at the read HtD spacing, a pre-write power level to maintain the head at the pre-write HtD spacing, a write power level to maintain the head at the write HtD spacing, and a idle power level to maintains the head at the idle HtD spacing.

Abstract: A magnetoresistive read/write head includes an integral top and side shields deposited on top of and substantially surrounding the multiple layers of the MR sensor stack. Such a design is particularly advantageous in CPP designs in which the only spacing necessary between the side shields and the bottom shield is due to a gap layer. The integral top and side shields design works both with CPP heads having pile bias stabilization as well as those having permanent magnet abutted junctions or patterned exchange bias stabilization. In addition, the design is also advantageous in CIP heads having permanent magnet abutted junctions or patterned exchange bias stabilization. In this latter embodiment, it may be possible to reduce the profile of the permanent magnet and any conductors to increase the efficacy of the side shields.

Abstract: Methods of controlling seeking of a transducer that is adjacent to a rotatable disk in a disk drive include determining a seek time associated with moving the transducer from an initial track on the rotatable disk to a target track on the rotatable disk, detecting a temperature associated with the disk drive, and determining if the detected temperature exceeds a temperature threshold. The methods may further include increasing the seek time to provide an increased seek time in response to the detected temperature exceeding the temperature threshold, generating a current command based on the increased seek time, and seeking the transducer from the initial track to the target track on the disk based on the current command. An apparatus configured to control the seeking of a transducer is also disclosed.