2797results about "Disposition/mounting of recording heads" patented technology

A magnetic head includes a slider body having a trailing surface meeting an air-bearing surface at a trailing edge, with a thin-film transducer disposed on the trailing surface of the slider body near the trailing edge. The thin-film transducer includes a coil embedded between first and second poles. A resistive heating element is disposed adjacent and electrically insulated from, the coil. Application of power to the resistive heating element causes expansion of at least the first and second poles.

A magnetic head includes a slider having an air bearing surface (ABS) and a trailing surface, with a transducer fabricated on the trailing surface. The transducer includes an adjunct pole disposed in a first general plane, the adjunct pole having a front edge that is recessed from the ABS and a rear edge. A main pole of the transducer is formed adjacent the adjunct pole, the main pole having a write tip that extends approximately to the ABS. A write coil having a first layer of turns is disposed in a second general plane below the adjunct pole. The magnetic head further includes a heating element, a portion of the heating element being disposed in the first general plane behind the rear edge of the adjunct pole.

A read / write head for use in a data storage device to control the low dynamic flying height in order to achieve high data recording storage capacity of magnetic hard drives. The read / write head is designed for use in a data storage device that includes a storage medium having a recording surface. The head comprises a pole tip region and an actuator. In turn, the actuator includes an excitation source for generating a magnetic field, and a magnetostrictive plate for expanding in response to the magnetic field, resulting in a protrusion in a section of the pole tip region along a direction towards the recording surface, so that the head flies above the recording surface at a flying height lower than a nominal flying height.

A magnetic recording head includes a recording magnetic pole, and a spin oscillation device including a first magnetic layer having at least one magnetic material layer, a second magnetic layer having at least one magnetic material layer, and a first nonmagnetic layer provided between the first magnetic layer and the second magnetic layer. The first magnetic layer and the second magnetic layer are antiferromagnetically coupled and / or magnetostatically coupled to each other. The first magnetic layer and the second magnetic layer are laminated in a direction generally parallel to a medium facing surface and generally parallel to a side surface of the recording magnetic pole intersecting with the medium facing surface.

A compact write element includes a conductive shield layer, an insulating write gap layer, a pole pedestal, a coil, and a conductive pole layer, and, in some embodiments also includes a backgap. The pole pedestal and the coil, and, in some embodiments the backgap, constitute a self-aligned array of components that may be formed in a single masking operation to allow for very tight tolerances between the components for a shorter yoke length. The pole layer is substantially flat and parallel to the conductive shield layer, providing for a shorter stack height. Also, a compact MR read / write head includes such a write element and a magnetic data storage and retrieval system includes the compact MR read / write head having such a write element.

A system and method for the production level screening of low flying magnetic heads in the manufacture of disk drive head disk assemblies (HDAs) is disclosed. A test disk is provided and has a plurality of bumps extending from at least one surface thereof. The test disk is rotated to fly a head of a head gimbal assembly selected from the group adjacent the surface of the test disk. An interaction of the head with one or more of the plurality of bumps may be sensed and the head gimbal assembly may be screened out from the group in response to the sensing of the interaction.

A disk drive is disclosed which executes a rotational position optimization (RPO) algorithm to select a next command to execute from a command queue relative to an estimated access time. If an external vibration is detected, the RPO algorithm increases at least one of an estimated seek latency, an estimated settle latency, and an estimated rotational latency for each command in the command queue.

A disk drive is disclosed comprising a head, a disk and a spindle motor for rotating the disk. An internal supply voltage is generated from a back EMF (BEMF) voltage across the windings of the spindle motor. The internal supply voltage is applied to a voice coil motor for use in parking the head during a spin-down mode. The internal supply voltage is compared to a threshold in order to activate a demand limit control signal. A periodic signal periodically disconnects the internal supply voltage from the VCM while the demand limit control signal is active.

Provided are a magnetic recording medium, in which a magnetic layer includes ferromagnetic hexagonal ferrite powder, a binding agent, and an oxide abrasive, an intensity ratio Int(110) / Int(114) obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, a vertical squareness ratio of the magnetic recording medium is 0.65 to 1.00, a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding a surface of the magnetic layer is equal to or smaller than 0.050, and an average particle diameter of the oxide abrasive obtained from a secondary ion image obtained by irradiating the surface of the magnetic layer with a focused ion beam is 0.04 μm to 0.08 μm, and a magnetic recording and reproducing device including this magnetic recording medium.

A disk drive is disclosed comprising a pulse width modulated (PWM) signal generator for generating PWM control signals applied to the driver switches of a voice coil motor (VCM). The PWM control signals comprise a PWM cycle time, a Tforward time interval of the PWM cycle time wherein a positive control voltage is applied to the VCM, a Treverse time interval of the PWM cycle time wherein a negative control voltage is applied to the VCM, and a Tdead time interval of the PWM cycle time wherein a substantially zero control voltage is applied to the VCM. The Tdead time interval is adjusted to control a magnitude of an actual ripple current flowing through the VCM.

A thin film magnetic head includes first and second shield layers that are positioned on both sides of a magnetoresistive (MR) stack with respect to a film surface orthogonal direction; a first exchange-coupling layer that is positioned between the MR stack and the first shield layer and that generates an exchange-coupling between a first magnetoresistive (MR) magnetic layer and a first magnetic control layer of the first shield layer; a second exchange-coupling layer that is positioned between the MR stack and the second shield layer and that generates an exchange-coupling between a second magnetoresistive (MR) magnetic layer and a second magnetic control layer of the second shield layer; a bias magnetic field application layer that is disposed at an opposite surface of the MR stack from an air bearing surface (ABS) and that applies a bias magnetic field to the MR stack in a direction orthogonal to the ABS; and pair of side shield layers that are positioned at both sides of the MR stack with respect to a track width direction. Each of the side shield layers includes a pair of magnetic layers that are antiferromagnetically exchange-coupled through a side shield ruthenium layer.

A disk drive is disclosed employing either back electromotive force (BEMF) spindle speed control or wedge spindle speed control. The BEMF spindle speed control is used to calibrate a reference time period representing an accumulation of a predetermined number of wedge-to-wedge times. During wedge spindle speed control, a wedge time period representing an accumulation of a predetermined number of wedge-to-wedge times is measured, and a wedge speed error is computed as the difference between the reference time period and the wedge time period.

Provided is a thin-film magnetic head that can stably generate electromagnetic field with a desired frequency, even under the existence of significantly strong write field with frequently reversed direction. The head comprises an electromagnetic-field generating element between the first and second magnetic poles. The electromagnetic-field generating element comprises a spin-wave excitation layer provided adjacent to the first magnetic pole and having a magnetization with its direction varied according to external magnetic fields, for generating an high frequency electromagnetic field by an excitation of spin wave. And a magnetization of the spin-wave excitation layer is biased in a direction substantially perpendicular to its layer surface by a portion of magnetic field generated from the first magnetic pole, and pin-wave excitation current flows in the electromagnetic-field generating element in a direction from the second pole to the first pole.

An apparatus that provides for rotation about two axes orthogonal to each other includes a gimbal having two arms adjoining a portion that is mounted to a base for rotation about a first axis. A shaft defining a second axis orthogonal to the first pivotally couples a mounting plate to the arms. The mounting plate has an arcuate edge with first and second parallel grooves therein adapted to receiving a drive cable. A drive cable that is engaged with a drive pulley is aligned by at least one idler pulley with the first and second grooves of the mounting plate. The drive cable has opposing free ends that are received in the first and second grooves of the mounting plate. A motor is coupled to the drive pulley for controlling the drive cable travel, to accordingly rotate the mounting plate to provide for orientating a device in a desired direction.

Methods and systems for write compensation for optimizing the performance of a data storage or communication channel are disclosed. In one embodiment, a method comprises determining channel sensitivity to modifications in write signal parameters, detecting systematic errors in a read signal recovered from data written with a first set of write parameters, and adjusting the write signal parameters by an amount determined from the channel sensitivity such that the systematic errors are reduced when data are written with the adjusted write parameters.

Provided is a magnetic recording medium exhibiting good electromagnetic characteristics in high-density recording The magnetic recording medium employed for magnetically recording signals with a track width equal to or less than 2.0 μm and reproducing the magnetically recorded signals, wherein said magnetic recording medium comprises a magnetic layer comprising a hexagonal ferrite ferromagnetic powder and a binder or comprises a nonmagnetic layer comprise a nonmagnetic powder and a binder and a magnetic layer comprising a hexagonal ferrite ferromagnetic powder and a binder in this order on a nonmagnetic support. Said magnetic layer has a thickness equal to or less than 0.2 μm, and said hexagonal ferrite ferromagnetic powder has an average plate diameter being 1 / 30 or less of the magnetically recorded track width as well as ½ or less of the thickness of the magnetic layer.

Provided are a magnetic tape, in which a magnetic layer includes a ferromagnetic powder, a binding agent, and an oxide abrasive, ΔSFD in a longitudinal direction of the magnetic tape calculated by Expression 1, ΔSFD=SFD25° C.−SFD−190° C., is equal to or smaller than 0.50, a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding a surface of the magnetic layer is equal to or smaller than 0.050, and an average particle diameter of the oxide abrasive obtained from a secondary ion image obtained by irradiating the surface of the magnetic layer with a focused ion beam is 0.04 μm to 0.08 μm, and a magnetic recording and reproducing device including this magnetic tape.

A disk drive that includes a base, a magnetic disk, a rotary actuator that carries a head for reading and writing data from the disk in a track-following mode under the control of a servo control system, and at least two sensors--one fixed sensor rigidly coupled to the overall disk drive and one mobile sensor mounted to the rotating actuator--for differentially detecting accelerations of the rotary actuator relative to the overall disk drive and its disk. The disk drive detects and actively compensates for accelerations imparted to a balanced actuator that has an effective imbalance. The fixed sensor is preferably mounted to a PCBA that is secured to the base. The mobile sensor is preferably mounted to an actuator arm of the rotary actuator, as far outboard as possible, and so as to align with the fixed sensor as the rotary actuator swings through its range of travel. The preferred sensors are linear accelerometers.

The present invention provides an improved method and apparatus for independently controlling phase and frequency using an oscillator having a plurality of stages in combination with a phase selector within a digitally controlled phase-locked loop, preferably, a read phase locked loop. The present invention provides a digitally controlled variable phase of the read timing loop in read channel integrated circuits associated with data storage devices. The phase selector has a digitally controlled fine interpolator with 12 states for further fine interpolation between at least two multiplexer phase outputs to provide a single phase output selected from a range comprising at least 2pi in selectable variable phase increments of 2pi / 96 radian. The combined oscillator with the phase selector within a phase locked loop controls phase by exact fractional increments of equally space phases of the operating frequency within the phase locked loop, therein controlling phase at all operating frequencies.

An MR element includes an MR stack disposed between first and second main shield portions, and a pair of side shields disposed on opposite sides of the MR stack in the track width direction. The first main shield portion includes a first exchange coupling shield layer that is exchange-coupled to a first antiferromagnetic layer. The second main shield portion includes a second exchange coupling shield layer that is exchange-coupled to a second antiferromagnetic layer. The MR stack includes a spacer layer, and first and second free layers with the spacer layer therebetween. The direction of magnetization of the first free layer is controlled by the first exchange coupling shield layer. The direction of magnetization of the second free layer is controlled by the second exchange coupling shield layer. Each side shield includes at least one shield-coupling magnetic layer that is in contact with and magnetically coupled to one of the first and second exchange coupling shield layers.

Provision is made to perform a write trial process in a stable manner at all times in a write trial area for the purpose of determining optimum recording power. Sub-areas of the write trial area are used successively from an inner circumference side of the medium to an outer circumference side of the medium with respect to the spiral direction that extends from the outer circumference side of the medium to the inner circumference side of the medium, and the sub-areas of the write trial area are used successively from the outer circumference side of the medium to the inner circumference side of the medium with respect to the spiral direction that extends from the inner circumference side of the medium to the outer circumference side of the medium With this provision, the write trial process is performed by accessing a sub-area portion of interest without accessing the sub-area portion having undergone the write trial, no matter which record layer is used. Servo control and address read can thus be stabilized. As a result, a seek operation toward the sub-area of interest is also stabilized, thereby achieving a stable write trial process.

A method for manufacturing a magnetic disk comprises the steps of depositing NiP (20) on a substrate (22); depositing NiNb (24) on the NiP; and laser texturing the NiNb. "Sombrero" shaped texture features are more easily formed on the substrate / NiP / NiNb structure than a substrate / NiP structure. The disk is completed by depositing an underlayer (e.g. sputtered Cr or NiP), a magnetic layer (e.g. a Co alloy) and a protective overcoat (e.g. by hydrogenated carbon).

An environmental control system, or data pack, is provided in accordance with embodiments of the present invention. The system allows for audio and video recording on hard drive media in situations where temperature, vibration and humidity would otherwise have prevented the use of such technology. The system can be used in conjunction with an event recorder for use in motor vehicles, trains and the like. The environmental control system includes a thermoelectric module connected to the hard drive and to a housing. The thermoelectric module is for transferring heat between the hard drive and the housing in response to an applied voltage in order to maintain a hard drive temperature within a hard drive operable temperature range. The vehicle operating temperature range includes temperatures outside the hard drive operable temperature range.

In an optical disc in / from which data is recorded or reproduced by irradiating a storage area on the optical disc with a laser, information containing recording velocity information (RVI) for recording / reproduction, which represents a linear velocity different from the standard linear velocity, and write strategy information (WSI) corresponding to the recording velocity information is stored in a land pre-pit or the like on the optical disc.

A system provided for protecting a disk drive from impact damages. More specifically, a disk drive is provided that includes an accelerometer interconnected to a printed circuit board that detects free fall of the disk drive. In addition, the velocity of spinning disks of the disk drive is also monitored to assess changes in velocity thereof that may indicate the presence of a tumbling condition. Furthermore, the change in acceleration measured by the accelerometer is monitored to prevent false indications of free fall due to common vibrations. Thus an enhanced system is provided that protects disk drives from the effect of free falls under a wide variety of conditions and allowing for drops from shorter distances to be identified.

Disk drive spin-up is staggered to reduce peak power requirements. Spin-up of the drives is controlled by selectively delaying voltage inputs to the disk drives. Alternately, spin-up of the drives is controlled by staggering the timing of communications to the disk drives.