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 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 disk drive includes a rotatable data storage disk, an interface, a transducer, a write buffer, an actuator, and a controller. The transducer is configured to read and write data on the disk. The interface is configured to receive data with associated write commands and a park signal. The write buffer is configured to temporarily store the data and associated write commands while the data waits to be written on the disk via the transducer. The actuator is configured to move the transducer between a parked position and tracks on a disk where data is read and written. The controller is configured to execute the buffered write commands by positioning the transducer relative to tracks on the disk while writing data from the write buffer to the disk, and is configured to respond to the park signal, which is indicative of an imminent transducer to disk contact condition, by moving the transducer to the park position without completing execution of the buffered write commands.

Abstract: A disk drive includes a drive housing, a storage disk, a slider and a drive circuitry. The storage disk has an inner and an outer diameter. The slider includes a read/write head and a slider mover that receives power from the drive circuitry to position the read/write head at a predetermined head-to-disk spacing during radial movement of the slider relative to the storage disk. The drive circuitry can direct a varying level of power to the slider mover during radial movement of the slider. In addition, the drive circuitry can increase the power to the slider mover as the read/write head nears a target track in order to decrease the head-to-disk spacing at the appropriate time. The drive circuitry can adjust the power to the slider mover so that the head-to-disk spacing remains within a predetermined range as the slider moves radially relative to the storage disk.

Abstract: A disk drive includes a drive housing, a storage disk, a slider and a drive circuitry. The slider magnetically interacts with the storage disk, and includes a read/write head that is positioned to have an actual head-to-disk spacing greater than zero nanometers during rotation of the storage disk. The drive circuitry can determine and/or monitor the actual head-to-disk spacing at any time during the operation of the disk drive based on an amplitude or a change in the amplitude of a signal such as a variable gain amplifier signal. In one embodiment, the slider includes a slider mover that receives current via the drive circuitry and causes a deformation of a portion of the slider to change the head-to-disk spacing based on the amplitude of the signal.

Abstract: A storage disk for a hard disk drive includes a homogeneously-formed body region, a first side region and a second side region. The body region includes a first body side and a second body side opposite the first body side. The first side region is secured to the first body side and the second side region is secured to the second body side. In one embodiment, the first side region is adapted to store data and the second side region is not adapted to store data. The first side region includes a plurality of layers formed from different materials relative to one another. The first side region has a first density that is different than a second density of the second side region. In one embodiment, the first side region has a mass that is different than a mass of the second side region. In an alternative embodiment, the first side region has a thickness that is different than a thickness of the second side region.

Abstract: Systems and methods from loading/unloading a data head for a disk drive provide for more efficient use of disk space. A method of loading/unloading a data head for a disk drive comprises determining a disk phase of a spinning disk arrangement, determining a loading/unloading position based on the disk phase, and loading or unloading the data head on or from, respectively, the spinning disk arrangement based on the determined disk phase. The determining a disk phase may be based on zero crossing of voltages for a three-phase motor associated with the spinning disk arrangement.

Abstract: Various embodiments of the present invention are directed to substantially eliminating transient changes in a flying height of a head during read-to-write and write-to-read transitions. In various embodiments, flying height transient compensation is provided to substantially maintain a desired flying height during one or both of read-to-write and write-to-read transitions.

Abstract: Detection of contact between a sensor, such as a data head or a slider, and a surface, such as the magnetic surface of a disk is achieved using the efficiency of actuator associated with the sensor. In this manner, the fly height of the sensor can be calibrated substantially continuously.

Abstract: A controller for a disk drive measures track misregistration, extracts non-repeatable runout from measured track misregistration, determines one or more components of non-repeatable runout at various radial locations of a disk, and compares the determined components to known values at different altitudes to determine an operating altitude of a disk drive.

Abstract: A disk drive for storing data includes a drive housing and an asymmetrical storage disk. The storage disk includes a body region, a first side region, and an opposed second side region. The side regions are asymmetrical relative to the body region. Various structures can be, alternately or in combination, incorporated into the second side region. For example, the second side region can include one or more stiffeners that increase the rigidity of the storage disk, a plurality of projections that improve fluid flow within the disk drive, a damping layer for damping vibration of the storage disk, and/or a constraining layer that enhances the damping properties of the damping layer. In other embodiments, the second side region includes a supplemental layer that balances the storage disk, an adsorption layer that adsorbs impurities, and/or a diffusion layer that filters unwanted particles.

Abstract: A method of determining side track erasure in a disk drive having a disk and a transducer. A target track and one or more side tracks proximate to the target track on the disk are selected, and recording parameters for recording signals on the target track and each side track with the transducer are selected. Thereafter, signals are recorded on each side track and then signals are recorded on the target track multiple times. A reduction in the integrity of the recorded signals on each side track due to recording signals on the target track multiple times is detected, and the detected reduction in the integrity of the recorded signals on each side track represents the amount of the erasure of the recorded signals on the side track. Recording parameters are changed based on the signal integrity reduction to minimize side track erasure.

Abstract: A disk drive includes a rotatable data storage disk, a transducer, and a controller. The transducer is configured to write data on the disk. The controller is configured to receive data from a host device, to measure at least one parameter that is indicative of a time varying characteristic associated with the disk drive, and to write the measured parameter and the data on the disk through the transducer. The time varying characteristic that is measured may include temperature, air pressure, flying height of the transducer relative to the disk, and/or a position error signal (PES) that is indicative of a radial location of the transducer relative to a desired location along a track on the disk. The measured parameters may be embedded within the data that is written on the disk, they may be written in a same track and/or sector as the data, and/or they may be written on a reserved portion of the disk.

Abstract: A method and apparatus for generating high quality real random numbers is provided. In particular, the present invention enables a hard disk drive of a computer to function as a generator of high quality real random numbers by monitoring one or more of a disk drive's parameters, wherein such parameters are subjected to environmental effects. The system of the present invention does not require the addition of any hardware not normally associated with a computer. According to one embodiment of the present invention, a parameter of the disk drive is monitored, and after processing and filtering the parameter is provided to an application as a random number. Monitored parameters may include the position error signal of a transducer head with respect to a track, temperature, channel gain, transducer head flying height, etc. According to one embodiment of the present invention, the various other parameters may be combined or used in concert to provide high quality real random numbers.

Abstract: A method and apparatus for providing a user selectable start-up current in a disk drive are provided. A user may select a relatively high start-up current to provide a relatively fast start-up time in a disk drive. Alternatively, the user may select a relatively low maximum current draw by the hard drive to enable a relatively low power, low cost power supply to be used in connection with the hard drive, for use with applications in which a relatively long start-up time is acceptable. In connection with applications in which a low cost power supply is to be used, the maximum current drawn by the disk drive may be limited to the amount of current required by the disk drive during seek operations.

Abstract: A method and system control the flight height of a transducer element of a slider mechanism operating in association with a storage disk. The invention adjusts the flight height of transducer element to a first flight height using an electromechanical control mechanism. The flight height of transducer element then achieves a second flight height using a thermal control mechanism. The thermal control mechanism is associated with a thermally responsive portion of transducer element. By heating the thermally responsive portion, a portion of transducer element becomes sufficiently proximate to the storage disk for the transducer element to respond to physical forces arising from electrostatic induction between transducer element and the storage disk. Flight height adjustment of transducer element from the second flight height to a third flight height may then occur using an electrostatic control mechanism which generates a physical force through electrostatic induction.

Abstract: The present invention generally relates to a disk drive and methods for operating the same. A venting assembly of this disk drive generally includes a slider having an air bearing surface system for generating positive pressure to urge the slider away from a data storage disk, and a suction cavity for generating negative pressure to urge the slider toward the surface of the disk. The slider of the venting assembly also generally includes a first venting hole extending through the slider within the suction cavity. A first valve of the venting assembly is generally associated with the first venting hole to at least assist in controlling airflow through the same. Contact between a load beam of the venting assembly and a corresponding load/unload ramp of the disk drive during unloading of the slider generally tends to open the first valve and substantially dissipate the negative pressure within the suction cavity.

Abstract: A PTP test subsystem of a magnetic disk drive identifies an undesired pole tip protrusion (PTP) condition, and takes steps to prevent problems associated with PTP. A PTP stressing mechanism stresses the disk drive during a PTP test mode to induce a PTP condition. A disk contact detection circuit detects when a head of the disk drive contacts the disk. A PTP write current determining circuit is also provided which comprises a write current level detector to ascertain a write current level at which the disk contact detection circuit detects when the head of the disk drive contacts the disk while the disk drive is stressed during the PTP test mode.

Abstract: A personal computer hard disk has disk media that comprises a primary portion and a backup portion; both portions are in the same hard disk housing. The backup portion is logically separate from the primary portion, and access to the logically separate backup portion is controlled by a backup access control mechanism. The backup access control mechanism may comprise a manually-actuable mechanism, such as a switch or a jumper, or it may comprise software provided in an ROM forming part of the internal memory of the hard disk.

Abstract: A PTP test subsystem of a magnetic disk drive identifies an undesired pole tip protrusion (PTP) condition, and takes steps to prevent problems associated with PTP. A PTP stressing mechanism stresses the disk drive during a PTP test mode to induce a PTP condition. A disk contact detection circuit detects when a head of the disk drive contacts the disk. A PTP write current determining circuit is also provided which comprises a write current level detector to ascertain a write current level at which the disk contact detection circuit detects when the head of the disk drive contacts the disk while the disk drive is stressed during the PTP test mode.