Abstract: A hard disk drive that includes a head that is coupled to a disk. The head has a flying height and an inductance. The disk drive also includes a circuit that detects a change in the flying height by sensing a change of head inductance. The circuit can inhibit a write operation if the change in inductance exceeds a threshold.

Abstract: Perpendicular recorded servo patterns are used such that a first and second servo fields can be positioned with a common border to define a desired track position.

Abstract: The minor coherence-errors suffered during servowriting of bursts in a phase burst servo pattern may contribute to significant written-in runout of the resulting pattern. Embodiments of the present invention enables the servowriting of both the zig/zag bursts and/or the digital information of the phase burst pattern all in one single revolution so that the common coherence errors of the zig/zag bursts can be canceled during demodulation. Such single pass servowriting of both zig/zag bursts can be accomplished by either using additional phase-adjustment circuitry or by shifting the phase of the write clock to allow servowriting of the bursts and/or digital information all at edges of (different) integer clock cycles. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures, and the claims.

Abstract: The minor coherence-errors suffered during servowriting of bursts in a phase burst servo pattern may contribute to significant written-in runout of the resulting pattern. Embodiments of the present invention enables the servowriting of both the zig/zag bursts and/or the digital information of the phase burst pattern all in one single revolution so that the common coherence errors of the zig/zag bursts can be canceled during demodulation. Such single pass servowriting of both zig/zag bursts can be accomplished by either using additional phase-adjustment circuitry or by shifting the phase of the write clock to allow servowriting of the bursts and/or digital information all at edges of (different) integer clock cycles. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures, and the claims.

Abstract: A storage device is configured to read and write data from one or more storage media. The storage device includes an actuator which reads and writes data. The actuator includes two or more read leads that connect to a pre-amp and run parallel to a write lead. The read leads are configured such that they cross at the middle, thus mostly canceling out the differences in induced voltage between the two read leads and reducing cross-talk.

Abstract: A storage device is configured to read and write data from one or more storage media. The storage device includes an actuator which reads and writes data. The actuator includes two or more read leads that connect to a pre-amp and run parallel to a write lead. The read leads are configured such that they cross at the middle, thus mostly canceling out the differences in induced voltage between the two read leads and reducing cross-talk.

Abstract: A method of determining the write head capacity during self test of a hard disk drive is described. Information related to the dynamic coercivity of the disk service is obtained. In one embodiment, a DC erase condition is produced onto the disk surface. An AC signal is provided to a write head such that a region on the disk surface is put into a state of substantially no direction of magnetization. The AC signal to cause this state will be related to the coercive current. The coercive current can be used to estimate the required write current at low temperatures and thus determine whether to reject the hard disk drive.

Abstract: Perpendicular recorded servo patterns are used such that a first and second servo fields can be positioned with a common border to define a desired track position.

Abstract: The gap of a write head on an arm of a rotating media storage device is positioned at an angle off perpendicular from an arm chord, which is a line defined from the center of the gap to the center of the pivot of the arm. This increases the skew for a written field on a disk. This increased skew can narrow the tracks and/or allow the use of a wider, less expensive write head.

Abstract: A servo method and system for generating a position error signal in a disk drive including a magnetic data storage disk rotating relative to a base, a data transducer assembly positioned at concentric data tracks by a rotary actuator referenced to the base and controlled by a digital servo system, the data transducer assembly having a magnetoresistive (MR) read element, the digital servo system employing multiple servo bursts in servo sectors embedded within the data tracks. During servo track positioning/following for each target head position relative to a track, a plurality of the servo bursts are selected, and combinations of the burst amplitudes of the selected servo bursts are obtained. A substantially continuous position error signal (C_PES) is generated based on the combinations of the burst amplitudes, indicating radial position of the read head relative to the target position.

Abstract: An optical servo head and method for reading position information on a medium, such as a magnetic disk, having a plurality of optical servo tracks in the form of relatively nonreflective regions on a reflective surface of the medium. With a magnetic disk, the nonreflective regions comprise concentric grooves etched in the disk surface and the reflective regions comprise the land areas between the grooves. The optical servo head is mounted on a carriage/head assembly of a disk drive and comprises an infrared light emitting diode, a collection lens, a routing mirror and a multicell photodetector.

Abstract: An optical servo head and method for reading position information on a medium, such as a magnetic disk, having a plurality of optical servo tracks in the form of relatively nonreflective regions on a reflective surface of the medium. With a magnetic disk, the nonreflective regions comprise concentric grooves etched in the disk surface and the reflective regions comprise the land areas between the grooves. The optical servo head is mounted on a carriage/head assembly of a disk drive and comprises an infrared light emitting diode, a collection lens, a routing mirror and a multicell photodetector.