Abstract: A write-inhibit signal is generated by a head-disk interaction sensor during a write process that is integrated with a suspension of a hard disk drive (HDD) when fly-height modulation of the slider is detected during a write process The suspension load beam includes a dimple and a laminated flexure. The laminated flexure includes a surface that is adapted to receive a slider and a surface that is adapted to contact the dimple. The head-disk interaction sensor is fabricated as part of the laminations of the flexure. The head-disk interaction sensor can be an accelerometer that senses an acceleration of the flexure when the slider contacts the disk of the disk drive and/or a pressure sensor that senses a pressure between the flexure and the dimple when the slider contacts the disk. A write-inhibit circuit is responsive to the sensor signal by inhibiting the write process.

Abstract: A system and method for performing write operations in a disk drive having a write stack drive is disclosed. The disk drive has two drives, a normal drive and a write stack drive. The write stack receives a write command from an array controller and performs write stack operations to store data from the write operations of the write command. The write stack drive includes a non-volatile stack cache memory comprising tracks to store the data. A metadata file identifies the current data stored within the write stack drive. The normal drive then executes the write operations of the write command.

Abstract: Rotary positioners integrally and pivotally stack a read magnetic head for reading a master disk and servo heads for writing to each surface of magnetic disks, the master disk and magnetic disks being stacked on a shaft of a spindle motor. Every surface of every magnetic disk is written by the servo heads in parallel while sharing a range of tracks. Simultaneously with the writing, checking magnetic heads stacked on a checking-dedicated rotary positioner read written data on the master disk and on each surface of the magnetic disks. A comparison logic circuit compares the read data from the magnetic disk surfaces with the data from the master disk. If an inconsistency is found, the contents of the master disk are overwritten on the corresponding magnetic disk surface through a correction servo pattern generator by the checking magnetic head.

Abstract: The invention provides a method insuring that each read channel optimization step is controllable in terms of quality divergence, that a systematic response can be made which can be readily automated. The method is applicable to a pre-existing read channel optimization (RCO) script. The method includes the following operations. Acquiring a first quality measure and a first parameter list. Performing the pre-existing RCO script creating a second quality measure and a second parameter list based upon the first parameter list. Convergence processing the first and second quality measures and parameter lists.

Abstract: A micro-actuator is comprised of a piezoelectric motor mounted on a flexure tongue with offsetting hinges, to perform a fine positioning of the magnetic read/write head. The substantial gain in the frequency response greatly improves the performance and accuracy of the track-follow control for fine positioning. The simplicity of the enhanced micro-actuator design results in a manufacturing efficiency that enables a high-volume, low-cost production. The micro-actuator is interposed between a flexure tongue and a slider to perform an active control of the fly height of the magnetic read/write head. The induced slider crown and camber are used to compensate for thermal expansion of the magnetic read/write head, which causes the slider to be displaced at an unintended fly height position relative to the surface of the magnetic recording disk. The enhanced micro-actuator design results in reduced altitude sensitivity, ABS tolerances, and reduced stiction.

Abstract: Provided are a method, system, and program for performing error correction in a storage device having a magnetic storage medium. A plurality of zones are defined in the magnetic storage medium, wherein each zone comprises a plurality of addressable locations in the magnetic storage medium. A determination is made as to whether a change of a signal-to-noise ratio for one subject zone of the plurality of zones exceeds a threshold. An operation is performed to improve the signal-to-noise ratio with respect to the subject zone of the magnetic storage medium after determining that the change of the signal-to-noise ratio exceeds the threshold.

Abstract: In a first mode, an R/W channel starts to monitor read information to thereby detect a servo mark contained in servo information, each time a servo controller generates a servo gate pulse. Upon detecting the servo mark, the R/W channel detects, from the read information, position information contained in the servo information and following the servo mark, at a timing determined by the detection timing of the servo mark. When the first mode has been switched to a second mode, the R/W channel detects the servo mark and position information using the synchronous method.

Abstract: Method and apparatus for detecting defects in a magnetic medium of a data handling system. The magnetic medium includes a number of user data wedges each disposed between an adjacent pair of servo data wedges. A predetermined data sequence is written to the user data wedges, and subsequently read to generate a readback signal. A sequence of discrete time sample values are generated from the readback signal. Defects in the medium are detected in relation to the magnitudes of the discrete time samples. A media scan controller outputs a first multi-bit information record having at least one bit composing the address of the user data wedge containing a defect, and a second multi-bit information record having at least one bit composing an address of the defect within the user data wedge. No information is written to the buffer when no defects are identified.

Abstract: A method (and structure) senses a rotational vibration of a disk drive. The disk drive includes a rotating disk. The disk includes a plurality of reference bits across a surface thereof. The method (and structure) includes detecting the reference bits across a pattern on the rotating disk, and analyzing a time interval between adjacent ones of the reference bits.

Abstract: Methods are provided for improving servo-demodulation robustness. SAM pattern detections are characterized as either good SAM detections or bad SAM detections. Further servo functions are then based on whether the detection of the SAM pattern in a servo wedge was characterized as a good SAM detection or characterized as a bad SAM detection.

Abstract: Position information PosN and PosQ are compared and position information Pos1 and Pos2 in which influences of an error of a position sensitivity gain appear oppositely are calculated. Subsequently, a weight gain G1=M and a weight gain G2=(1?M) are obtained from the position information Pos1. A multiplication value obtained by multiplying the third position information Pos1 by the weight gain G1 and a multiplication value obtained by multiplying the fourth position information Pos2 by the weight gain G2 are added and synthesized, thereby calculating a decoded position.

Abstract: An acoustic emission sensor is mounted on a flying slider opposed to a rotating recording medium, for example. The acoustic emission sensor outputs a detection signal in response to the sound of collision. When a protrusion exists on the recording medium, the flying slider is expected to collide against the protrusion at a predetermined fixed angular position. A variation is induced in the detection signal based on the collision between the flying slider and the protrusion in synchronization with the rotation of the recording medium. Specifically, when a variation is synchronized with the angular position signal of the recording medium, the variation should correspond to a protrusion existing on the surface of the recording medium. If the component corresponding to the variation is extracted out of the detection signal, a protrusion on the recording medium can be determined at a higher accuracy.

Abstract: A plurality of redundant sets of servo data are recorded on a magnetic hard disk. The set meeting a predetermine criteria is employed when the hard disk is assembled into a hard disk drive. The determination of which set has the criteria may be conducted by the disk drive itself. The criteria may include a determination the set of servo data having meeting a minimum quality criteria or the fewest errors. The criteria may include a selection of a set of servo data having a specific pattern where the prerecorded sets may comprise a differing servo patterns that may be used by disk drives requiring specific servo patterns. The servo data are printed onto the hard disk by means of a stamper or mask having all the sets of servo data.

Abstract: An information recording system includes a storage medium, such as a magnetic or an optical medium, that is formed to have a plurality of adjacent tracks. Each track includes a plurality of storage elements that are arranged substantially along the track in a regular manner. A head disposed in proximity to the storage medium and has a width that spans at least two adjacent tracks. The storage elements are further arranged substantially along first and second axes, such that the first and second axes are substantially perpendicular to each other and are each substantially oriented 45° from an along-track direction associated with a track. The head reads and/or writes information from at least two adjacent tracks spanned by the head.

Abstract: Method of accurately measuring various kinds of non-linear transition shifts (NLTSs) in the magnetic recording/reproduction using an MR-type reproducing head is provided. According to the method, the data of a reference bit-string pattern are sent, as reference signals, to a magnetic disk 2 via a head IC 5 and a magnetic head 3 so as to be magnetically recorded. A first predetermined harmonic component Vnref is measured from the reproduced signals of the record data detected by the magnetic head 3, a bit-string pattern is selected from plural kinds of predetermined bit-string patterns, the data of the selected bit-string pattern are sent, as to-be-measured signals, to the magnetic disk 2, a second predetermined harmonic component Vnpat is measured from the reproduced signals, and the NLTS is calculated from Vnref and Vnpat.

Abstract: A magnetic head is disposed opposite to a magnetic disk having a first recording area capable of facilitating writing information to the magnetic disk when the surrounding temperature is low, and a second recording area capable of surely holding information written to the magnetic disk when the surrounding temperature is high. Information is written to the first recording area when the surrounding temperature is low and is transferred later to the second recording area.

Abstract: A method of encoding and decoding data involving the simultaneous application of pulse width modulation and pulse position modulation systems to data intended for storage on a magnetic disk medium.

Abstract: A processor processes data read from plural data tracks on a data-containing medium. The data tracks include markers. The processor determines if markers are detected in a predetermined number of the tracks within a predetermined time interval starting with detection of a first marker. In first and second embodiments, the number equals all the read tracks and less than all the read tracks. In the second embodiment, the processor asserts the markers into the data associated with the tracks that do not have detected markers.

Abstract: By bring a master carrier and a slave medium into close contact with uniform force when executing magnetic transfer by applying transfer magnetic field in the state that the master carrier and slave medium is in confronted close contact and received within a holder, inferiority of transfer such as omission of signals is prevented and quality of transfer signals is enhanced. The magnetic transfer apparatus executes magnetic transfer by applying transfer magnetic field by means of a magnetic field applying apparatus 5 after a master carrier 3, 4 bearing transfer information and a slave medium 2 to be transferred are brought into confronted close contact and received within a holder 10, wherein said holder 10 has a substantially circular shape and in particular, the circularity of holder is not less than 98%, wherein the flexural rigidity=Ed3/12 determined by Young's modulus E and thickness d of the holder is in the range of 0.

Abstract: A master carrier for magnetic transfer is equipped with a substrate having a land/groove pattern. The land/groove pattern is formed from a magnetic material and corresponds to information that is transferred to a magnetic recording disk. Each land in the land/groove pattern has four round corners whose radius is from 1% through 47% of the width of a data track on the disk.