Abstract: A method and data storage device are provided that reduce off-track motion due to resonant modes in the storage device. The off-track motion is reduced by sensing movement with a sensor located on a suspension assembly of the storage device. Based on this sensed movement, the sensor generates a signal that is used to drive a control system to minimize the off-track motion.

Abstract: A magnetic storage medium formed on a front major surface of a tape substrate defines a multiplicity of longitudinal data recording and playback tracks, each track having a nominal lateral location relative to the other tracks: and a predetermined optically manifested track servo pattern defined on the back major surface of the tape for indicating lateral displacement of the tape from a nominal lateral location of the track during tape movement across a read/write head. A magnetic tape recording and playback system employing the magnetic storage medium is also disclosed.

Abstract: A system and methods for efficiently performing media writing functions is disclosed. The system and methods include: detecting media movement with respect to a base and heads during reading and writing, and moving the heads in response; using an interferometer, such as a dual beam differential interferometer, to dynamically monitor disk position and address perceived errors; and minimizing repeatable and non repeatable runout error by writing data, such as servo bursts, in multiple revolutions to average adverse runout conditions. The present system has the ability to use an interferometer to enhance media certification and perform on line, in situ monitoring of the media, and includes shrouding, head mounting, disk biasing, and related mechanical aspects beneficial to media writing.

Abstract: A magneto-optical clock head is disclosed. The magneto-optical clock head allows a longitudinally recorded clock track to be read from a disk surface from a position outside of a head-disk assembly (HDA). The clock track has sections of alternating magnetization which define transitions. Importantly, the magneto-optical clock head is used to sense the transitions using the transverse Kerr effect, as opposed to the longitudinal Kerr effect as used in one prior technique. In one embodiment, the magneto-optical clock head includes a light source for generating a p-polarized beam which is aligned in such a manner that it strikes the clock track. A reflected beam is then produced which has an intensity that varies based upon the direction of the magnetization of the sections of alternating magnetization of the clock track due to the transverse Kerr effect.

Abstract: A method of correcting a position detection signal with a high precision in a short time and a position detection device able to be made compact and low cost, comprising detectors for outputting position detection signals including two signals having a phase difference of 180 degrees along with movement of an object to be detected and a signal processor for obtaining an offset voltage level by averaging the position detection signals and shifting a position detection signal so that a reference voltage level of a center of amplitude matches the voltage level. Also, the signal processor corrects an amplitude of a position detection signal by using two signals having a phase difference of 90 degrees.

Abstract: A method for detecting head-to-disk interference events in a disk drive is provided. The invention comprises coupling a transducer to an air filter in the disk drive, wherein the transducer detects changes in magnetic readings due to debris produced by physical contact between a read/write head and a magnetic storage medium (head crash). The recirculation filter is monitored during disk drive operations and comparing magnetic readings from the transducer with defined parameters. If the transducer readings exceed the defined parameters, the spindle motor of the disk drive is shut off, thus stopping the rotation of the disk and minimizing data loss and damage due to the head crash.

Abstract: A thermal-assisted magnetic storage device includes a magnetic recording media of a transparent material, a first marker of a material that is optically singular compared with materials therearound, and a magnetic head disposed on a magnetic head slider facing a recording surface of the magnetic recording media. A light-beam pickup faces the other surface of the magnetic recording media, so as to emit light therefrom to the surface of the magnetic recording media. A second marker is disposed on the magnetic head slider for roughly guiding the light to the first marker. An alignment between the light and the magnetic head is performed in accordance with the light reflected from the first marker.

Abstract: A device and a method are provided in which stable tracking control can be carried out even in an arbitrary phase by optically reading pits provided in a disk when information is recorded on and reproduced from the disk with a magnetic head. With respect to difference signals obtained from a main beam signal and sub-beam signals obtained through three-beam type photodetectors, gain correction is executed in variable gain amplifiers, respectively, so that output signals therefrom have same amplitude levels and are different in phase by 90 degrees in a track crossing direction, and thus a tracking error signal is generated by being synthesized from the output signals. Based on the tracking error signal, tracking control is carried out.

Abstract: The present invention offers an apparatus and associated method to detect a skip write error occurring during a data storage device write process. The capacitance between the read/write head and the disc surface, called the “parasitic capacitance,” is used to determine whether a skip write error has occurred. The amount of parasitic capacitance is determined by monitoring the frequency change at the input of an oscillator of test circuit. A change in the read/write head fly height causes a change in the parasitic capacitance and a corresponding change in the frequency. The parasitic capacitance is compared to a threshold limit to determine whether a skip write error has occurred. The write operation is suspended when a skip write error is detected and a rewrite procedure is instituted.

Abstract: A method for writing servo information to a disc rotatably mounted to a spindle motor. A measured cage frequency is obtained from a written reference track, from which an actual cage frequency is predicted. The predicted cage frequency is then used to derive compensated position commands. During a servo write interval, the compensated position commands are used to control the head such that the head follows the disc movements caused by the cage frequency.

Abstract: A positioning mark of a soft magnetic film is provided at the center of a master disk, and a beam from a light source irradiates the position of the mark. When a optical reception sensor using a CCD recognizes the mark, the recognizability of the positioning mark can be improved by using a wavelength selective filter or a laser as the light source. Additionally, the recognizability of the positioning mark can be improved by forming the positioning mark using a material other than a soft magnetic material.

Abstract: A disk drive apparatus. The apparatus has a first drive device and a support member coupled to the first drive device. The support member has a tongue portion and a gimbal portion. The tongue portion is coupled the gimbal portion. A fixed drive device is formed within a first portion of the tongue portion. A movable drive device is operably coupled to the fixed drive device and formed within a second portion of the tongue portion. A read/write head is coupled to the movable drive device. A voltage source is coupled between the fixed drive device and the movable drive device to cause movement of the read/write head by forming an interaction between the fixed drive device and the movable drive device.

Abstract: A disk drive apparatus. The apparatus has a platter operably coupled to a servo drive device. The servo drive device is adapted to rotate the platter about a fixed axis. The apparatus also has a support member operably coupled to the platter to move the support member about one or more active regions on a surface of the platter. The apparatus has a read/write head including an active portion and a support portion. The support portion is coupled to the support member. The active portion is operably coupled to the platter to read and/or write information to the surface of the platter. A piezo electric actuating material is coupled between the support portion of the read/write head and the support member. A first electrode is coupled to a first side of the piezo electric actuating material. A second electrode is coupled to a second side of the piezo electric actuating material.

Abstract: An optical disc player, which compensates for an eccentricity, is provided including: a spindle controller, a pickup, an RM amplifier, a focusing servo, a tracking servo and an eccentricity compensator. The spindle controller rotates an optical disc. The pickup has a focusing actuator and a tracking actuator and reads information on the optical disc. The RF amplifier detects and amplifies a focusing error signal and a tracking error signal from information on the optical disc obtained from the pickup. The focusing servo controls the focusing actuator in response to the amplified focusing error signal. The tracking servo outputs a tracking control signal in response to the amplified tracking error signal. The eccentricity compensator outputs a signal which compensates for the eccentricity of an optical disc in response to the output signal of the spindle controller, the amplified tracking error signal and the amplified tracking control signal.

Abstract: A system and methods for providing offset information on a storage medium are provided by writing at least one unalterable mark on the storage medium during a manufacturing formatting process. The unalterable mark(s) are variably offset from a fixed position. The amount of offset represents a first source of unique information. The unalterable mark(s) themselves comprise a second source of information. Both sources of information are combinable and may be utilized in connection with the generation of a unique serial number for the storage medium or for other digital rights management purposes.

Abstract: A magnetic-disk evaluation apparatus includes a magnetic head positioned relative to a magnetic disk including temporary servo signals. Fluctuation of a magnetic head in a seek direction is measured using a measurement device. A measuring rotating arm moves in tandem with a rotating stage holding a rotary positioner. The measurement device is on the measuring rotating arm. The rotary positioner is controlled on the basis of temporary servo signals to position the magnetic head on a circle, concentric from a center of a spindle motor. Fluctuation of the magnetic head in the seek direction is measured to detect the displacement of the magnetic head and to determine whether the temporary servo signals are acceptable based upon the displacement and an outside standard.

Abstract: A device for monitoring lubricant within a disk drive includes a reservoir packet impregnated with lubricant. The reservoir packet is disposed between a first metal screen and a second metal screen such that a lubricant reservoir transducer is created. The capacitance of the lubricant reservoir packet is monitored and when it falls below a predetermined percentage of the initial capacitance, a user is warned to back up the files contained in the disk drive before failure due to lack of lubricant occurs.

Abstract: A magnetic recording apparatus includes a laser light source (132), a recording magnetic head (131) and a magnetoresistive element. The recording magnetic head includes a pair of magnetic poles (100 and 101), between which the magnetoresistive element is interposed. A rotary actuator (Sa) positions the recording magnetic head at a desired track of a magnetic recording medium. A laser beam can be radiated onto the magnetic recording medium to raise the temperature of a region (302) of the medium. This region has a width of the order of the track width. The raised temperature lowers the coercive force of this region, where a recording magnetic field can be applied for high density recording. The rotary actuator may form a yaw angle (&thgr;) with a track of the magnetic recording medium. Even in this case, the recording magnetic head (131) and the reproducing element have no tracking offset from the code track.

Abstract: A hard disk device includes a servo control unit that constitutes a servo loop for a head seek for performing read/write of data from/to a recording medium, a correction signal generation unit for generating a correction signal for correcting a control by the servo control unit based on an output of a predetermined sensor, and a correction signal control unit for estimating an effect of supplying the correction signal to the servo loop and for controlling whether or not the correction signal is to be supplied to the servo loop in response to a result of the estimation. Moreover, the gain of the sensor is dynamically controlled in response to the above estimation result.

Abstract: A method and apparatus for positioning a transducer relative to a storage medium in a storage device. The storage medium is moved relative to the transducer by a motor at a rated storage medium velocity. The storage medium has a plurality of tracks, each having a first edge and a second edge. The first edge and the second edge respectively comprise surface profile variations having a temporal frequency at the rated storage medium velocity. The surface profile variations of the first and second edges are phase modulated, i.e., have a phase difference relative to one another. First and second responses, e.g., thermal responses, are respectively induced in the transducer by the phase modulated surface profile variations of the first and second edges. The transducer may be positioned by a controller, for example, based on at least one of the first and second thermal responses. A storage medium having phase modulated surface profile variations is relatively easy to fabricate.

Abstract: A method for writing servo information to a disc rotatably mounted to a spindle motor. A measured cage frequency is obtained from a written reference track, from which an actual cage frequency is predicted. The predicted cage frequency is then used to derive compensatedposition commands. During a servo write interval, the compensated position commands are used to control the head such that the head follows the disc movements caused by the cage frequency.

Abstract: Magnetic alignment marks are recorded on a recording surface of a magnetic hard disk to mark the location where the disk is abutted against the hub of the spindle of a multiple-disk servo-writer. The alignment marks for each recording surface may be different so as to distinguish between top and bottom disk surfaces so that when the discs are assembled onto the spindle of a disk drive they may be assembled with the proper orientation, i.e., the top surface is mounted “up.” The marks may be large, low frequency patterns that are both written and detected by non contact means other than the servo-track writer's or the disk drive's heads.

Abstract: A magnetic tape has a guide track for optically obtaining a tracking signal and an independent information track for storing information. The magnetic tape is partitioned into different kinds of zones. The guide tracks are provided with grooves or pits serving as tracking marks, and the tracking marks are selectively located in the zones depending on the kind of zone. Thus, the track spacing of the guide tracks in each zone can be increased, so that a tracking control can be performed for a high density recording medium without reducing the spot size of the light.

Abstract: An apparatus having a first system for forming a composite light beam of two light beams to be made to interfere with each other, a splitting member for amplitude-splitting the composite light beam into three or more split light beams in the same area, and a second system for obtaining interference light beams of different phases from the plurality of split light beams.

Abstract: A system for reading data from recording media having topographical features readable with a slider-mounted non-magnetic transducer sensitive primarily to changes in local aerodynamic boundary conditions.

Abstract: An apparatus for detecting the relative displacement of a surface to be detected, and an apparatus and method for recording information on a hard disc of a hard disk drive using such a detecting apparatus, the detecting apparatus comprising an interference optical system for condensing a light beam on the surface to be detected, and making the reflected light from the surface to be detected interfere with the condensed light beam to thereby form an interference light beam, light receiving means for receiving the interference light beam and outputting bright and dark signals attributable to the relative displacement of the surface to be detected, and condensed light information supplying means for separating part of the reflected light from the surface to be detected from the optical path until the reflected light arrives at said light receiving means, and utilizing the separated light beam to detect the condensed state of the incident light beam onto the surface to be detected or make the condensed state obse

Abstract: A position sensor includes a stationary platform and a moveable platform. The position sensor further includes at least one beam coupling the moveable platform to the stationary platform. The at least one beam includes piezoresistive material that is positioned tolprovide an indication of a movement of the moveable platform relative to the stationary platform.

Abstract: An active control mechanism and method for stabilizing a servo-controlled actuator system such as an actuator system in a data recording disk drive by compensating the vibrational modes of the actuator's arm assembly. The control mechanism has a sensing arrangement which can include one or more individual sensors attached to the actuator at locations where they generate signals in phase with the vibrational modes, and especially with all the low-frequency major vibrational modes, of the arm assembly. A control mechanism derives from the signals an adjustment signal consisting of three corrective terms—a stiffening correction, an active damping correction, and an inertia correction by a phase correction. Furthermore, high-frequency out-of-phase modes can be stabilized by appropriately shifting the phase of the signals. The adjustment signal is used in the feedback control loop to stabilize the actuator system.

Abstract: A servo track writing apparatus (10) for writing servo tracks (16) on a media disk (14) of a disk drive assembly (12) having a Positioning arm (22) with a through hole (28) therein. The writing apparatus (10) has a laser source (29) which directs a source beam (30) through a polarizing beam splitter (32) and a quarter-wave plate (34) to either pass through the through hole (28) and reflect off of the media disk (14) as a reflected beam (38), or to be reflected from regions of the positioning arm (22) proximate to the through hole (28) as a reflected beam (56). The writing apparatus (10) further has a remote tracking arm (42) with two photodiodes (40a, 40b) suitably mounted thereon to receive the reflected beams (38, 56). The tracking arm (42) is caused by a motive means (54) to precisely track the positioning arm (22) of the disk drive assembly (12).

Abstract: A disk drive with a detector circuit is connected to the distal end of a two-stage actuator. The actuator has a micro actuator for fine track positioning of a read/write head relative to a disk. Intermittent contact between the head and the disk produces forces that are detected and measured by the micro actuator drive circuitry. These measurements are used to determine if excessive contact is occurring between the head and the disk. Alternatively, the present invention also uses a differential method where the output signals from multiple micro actuators are compared to improve noise immunity. In addition, comparisons between the forces at the proximal and distal ends of the micro actuators are used to better identify the source of such forces. For example, this allows the system to distinguish between common mode forces such as those generated by windage and flex cable bias, from forces generated by intermittent head-disk contacts.

Abstract: This specification discloses an apparatus comprising a first system for forming a composite light beam of two light beams to be made to interfere with each other, a splitting member for amplitude-splitting the composite light beam into three or more splitted light beams in the same area, and a second system for obtaining interference light beams of different phases from the plurality of splitted light beams.

Abstract: In a magnetic memory drive, a diffraction grating 16 receives a beam emitted by a light source 1 to generate three beams of 0th-order and ±1st-order light beams, and a condensing system 17 converges the beams on a magnetic recording medium 4. The beams reflected from the medium is received by a photodetector 15 which outputs signals corresponding to quantities of the received beams, and a signal processor 61 processes the signals to output a tracking error. The photodetector comprises a plurality of light-receiving sections.

Abstract: A time-based optical servo system includes at least one optical indicator mark located on at least one servo track of a data storage medium. Alternatively, a pattern of optical indicators is repeatedly recorded in the at least one servo track. A servo read head assembly coupled to a transducing head assembly includes two elongate and non-parallel detection devices having a known relative geometry. The detection devices are adapted to detect the optical indicator marks and determine the time period required for each optical indicator mark to pass between the detection devices. This time period is used to calculate the location of the transducing head assembly relative to the storage medium in a translating direction and produce a position error signal (PES) based thereon.

Abstract: An improved servo system having an optical head array integrated into the magnetic head, and optical servo tracks incorporated on the magnetic side of a medium. The optical head array includes a light source array that individually illuminates the optical servo tracks through a beam splitter array and a lens array. Light beams incident on the optical servo tracks are individually reflected back through the lens array and beam splitter array to respective bi-cell photo detectors. The signals from the bi-cell photo detector are amplified by respective differential amplifiers to produce error signals indicative of the alignment of the magnetic head with the optical servo tracks. The error signals are combined by a circuit to produce a position error signal.

Abstract: In an information recording method of the present invention by carrying out recording data while carrying out tracking servo accurately, high density recording of signals at a good S/N can be carried out, and high density recording by a vertical magnetic recording system can be carried out. A magnetic disk comprises a magnetic recording layer, and the magnetic recording layer is magnetized in advance such that magnetized regions A and B having different magnetization directions are formed. At a time of recording data, vertical magnetic recording is carried out by a magnetic head while carrying out accurate tracking servo by optically tracking by a magneto-optical effect utilizing a difference in the magnetization directions of the magnetized regions A and B. Therefore, high-density recording at a good S/N is possible.

Abstract: An apparatus is constructed to record and/or reproduce information through a head on or from a disk which is an information recording medium. The apparatus has a first driving motor for supporting and rotationally driving the disk; a second driving motor for supporting and rotationally driving the head; a detection unit for detecting a nonsynchronous deflection component of a rotating part of the first driving motor; and a control unit for controlling the second motor, based on detection of the detection unit, so as to make the head track the nonsynchronous deflection component.

Abstract: A disk drive system includes a light source (110), such as an LED, mounted on the magnetic head. The LED (110) is patterned to form a fine pitched mask. The diverging light off the LED radiates toward a fixed, faceted optical reflector (112). The faceted array includes a plurality of spaced aspherical reflectors. The faceted array projects a portion of the light to a diffraction limited focus detector (114).

Abstract: A head-controlling device of a disk apparatus is provided that can precisely move a head stepwise to the position of each track on a recording surface of a disk. When detection output values A1 and B1 of phases A and B that are out of phase satisfy a relational value, a determination is made that a magnetic head is aligned with the position of a track. The calculation of the relational value of the phase A and the phase B detection values makes it possible to reliably align the head with each track position even when the phase difference of the two phases is not correct.

Abstract: In order to position a rotary actuator, a positioning device is coupled to the actuator. The positioning device has a coupling shaft and springs which respectively surround top and bottom portions of the shaft and are coupled thereto by respective coupling rings. The springs apply oppositely directed torques to the shaft such that one spring urges the shaft in a clockwise direction towards a stop position and the other spring urges the shaft in a anticlockwise direction towards that stop position. The stop position corresponds to an intermediate rotary position of the actuator.

Abstract: A magnetic disk unit which can provide a sufficient PD output of laser beams for optical tracking. The magnetic disk unit comprises a diffraction grating for splitting laser beams from a laser source into a plurality of beams; an aperture for narrowing a plurality of laser beams from the diffraction grating and light beams reflected from the recording medium; an objective lens for converging a plurality of laser beams, radiating the laser beams onto the recording medium, and guiding light beams reflected from the recording medium to the aperture; a beam splitter for splitting the reflected light beams having passed through the aperture; and a light receiver for receiving light beams split by the beam splitter. The objective lens is an objective lens telecentric to the image side.

Abstract: A method of refreshing magnetization of a servo pattern in a magnetic medium within a disc drive is provided, wherein the servo pattern is at least partially defined by physical features of the medium. The method includes reading servo information through a transducer in the disc drive from a first portion of the servo pattern. The transducer is positioned at a radial position relative to the medium based on the servo information. The magnetization of a second portion of the servo pattern is then refreshed at the radial position with a magnetic field generated by the transducer.

Abstract: A method and apparatus for detecting a topographic feature on a media is described. More particularly, a light scatter detector is coupled to an atomic force microscope. The detector is used detect scattered optical energy reflected from the surface of the media to identify the topographic feature. The atomic force microscope may then be positioned in response to the topographic feature identified.

Abstract: An apparatus and method for determining and adjusting the static attitude of a head suspension or a head suspension assembly for use in a dynamic storage device. An apparatus in accordance with the present invention includes a workpiece support and an adjust device, operatively positioned with respect to the workpiece support, for adjusting the head suspension. The adjust device includes first and second clamp portions for restraining a gimbal arm and an adjust body for deforming the restrained gimbal arm while the gimbal arm is restrained by the first and second clamp portions.

Abstract: An HDA includes a base, a disc stack coupled to a spindle rotatably attached to the base by a spindle shaft and spindle bearing. An actuator assembly is pivotally attached to the base at a pivot shaft. Attached to one end of the actuator assembly proximal the disc stack is one or more transducers for reading/writing information from/to the discs. A servo writer includes a controller for moving the actuator during the servo writing process. The controller moves the servo writer at the cage frequency of the spindle bearing to lessen the relative motion between the transducer head and the disc as the servo information is written to the disc. The controller also may be programmed to move the transducer at both the spindle rotation frequency and the cage frequency of the spindle bearing to lessen the relative motion between the transducer and the disc during the servo writing process.

Abstract: A method for evaluating head flight characteristics in a disc drive includes placing a non-contact voltmeter (NCV) probe into close proximity to a disc, the probe sensing disc potential in relation to a quantity of electrical charge present on the disc. The disc is accelerated with the head initially remaining in contact with the disc, and the disc potential is monitored until a rotational velocity is achieved sufficient to cause the head to separate from the disc. A head take off velocity is thereafter determined in relation to a detected change in the measured disc potential. A head touchdown velocity is similarly determined by initially accelerating the disc to separate the head therefrom, and then monitoring the disc potential as the disc is decelerated to bring the head back into contact with the disc.

Abstract: A driving device for performing a recording and/or reproducing operation for a recording medium, such as a flexible disc, and a fixed speed movement servo method carried out on such driving device. A head for recording and/or reproducing the information for a recording medium is run at a fixed speed using initial servo parameters as certain fixed values to calculate optimum servo parameters. Using the calculated servo parameters, constant speed servo is executed to realize the head running at a fixed speed. This achieves constant speed movement at a certain speed within a pre-set speed range regardless of individual characteristics or occasional posture of the recording/reproducing apparatus.

Abstract: A magnetic storage medium formed on a front major surface of a tape substrate defines a multiplicity of longitudinal data recording and playback tracks, each track having a nominal lateral location relative to the other tracks: and a predetermined optically manifested track servo pattern defined on the back major surface of the tape for indicating lateral displacement of the tape from a nominal lateral location of the track during tape movement across a read/write head. A magnetic tape recording and playback system employing the magnetic storage medium is also disclosed.

Abstract: The diffraction-based monitoring techniques described herein can be used, for example, as quality assurance measure in manufacture of magnetic recording media with servo tracking. In one embodiment, the invention presents a system comprising a light source such as a laser that directs light upon a surface of a magnetic recording medium. The magnetic recording medium has two or more physical marks, and the light striking the magnetic recording medium produces a diffraction pattern. A light detector such as a photodiode detects some or all of the diffraction pattern. The physical marks may be servo tracks on the magnetic recording medium, and the detected diffraction pattern is a function of the characteristics of the servo tracks.

Abstract: An eccentricity compensating apparatus of a disk drive servo system using frequency response characteristics of an actuator actuating a head to a position on a disk to read data on or reproduce data from the disk. The apparatus includes an error detector that detects a position error between a reference head position and an actual position of the head on the disk and a first compensation controller that receives the position error from the error detector and changes the actual position of the head to compensate for the position error.

Abstract: A magnetic disc apparatus comprises a magnetic disc and a magnetic head for recording and/or playing back an information signal on the magnetic disc. A control signal is generated on the basis of a servo signal recorded on the magnetic disc. The position of the support arm is detected by a hologram grating provided on the support arm and by a hologram sensor unit mounted on a base, whereby a position signal is generated. The control signal is corrected on the basis of the position signal. The actuation of the support arm is controlled based on the corrected control signal, such that the magnetic head can be positioned with respect to the magnetic disc with high accuracy.