Abstract: The invention presents techniques for marking data storage media and responding to disturbances in the marking process. In one embodiment, the invention presents a system that uses a laser to emit a beam to ablate physical marks in a data storage medium. The system includes a sensor such as an optical sensor, configured to detect the position of the data storage medium and to generate a position signal as a function of the position of the data storage medium. An optical device, controlled by an actuator, directs the beam from the laser to an ablation site on the data storage medium as a function of the position signal.

Abstract: A method and an apparatus select the operational spindle rotation rate for a disk drive based on measured performance of the head-disk assembly. The position error values are measured and analyzed to generate a position error metric. Based on the value of the position error metric, an operational spindle rotation rate is selected for use when the head-disk assembly is combined with a controller to produce a disk drive.

Abstract: A tape cassette includes a magnetic tape, a cassette housing in which the magnetic tape is housed, and a memory device attached to the housing. The memory device stores features of data recorded in the magnetic tape. Also, the features include image data, audio data, and control data.

Abstract: A method and apparatus for a variable mode multi-media data object storage device. Large digital objects can be quickly downloaded in approximately a minute. The digital objects can be utilized or played back at real-time speeds. Utilization or playback consumes minimal power, allowing the disk to support portable devices operating on battery power. The storage device uses multiple disk rotation speeds to support multiple modes of operation. The storage device operates in at least two modes of disk drive operation, supporting a fast platter rotation speed for writing and a slower platter rotation speed for reading. The multiple rotation speeds operate in conjunction with a head assembly configured with at least one head for reading and multiple heads for writing. When writing, the disk spins at the faster rotation speed. When in utilization or playback mode, the disk spins at the slower, power conserving rotation speed.

Abstract: In a magnetic tape drive for accessing a magnetic tape contained in a memory built-in cartridge, a logical beginning of tape is assigned and updated for the magnetic tape that is being accessed. The quality of data that is read from the magnetic tape is monitored and the number of times the magnetic tape has been accessed is recorded. It is determined whether the quality of data that is read and the number of times the magnetic tape has been accessed satisfy predetermined criteria. When the criteria are satisfied, the logical beginning of tape is caused to be updated. Information on the logical beginning of tape position of the magnetic tape is stored to the built-in memory. When the magnetic tape is loaded, the information on the logical beginning of tape position of the magnetic tape is read from the built-in memory.

Abstract: The present invention offers a time efficient means to determine and eliminate dynamic track squeeze error. The present invention can be used to correct imperfections in tracks written by a conventional servowriter or using self-propagating servo writing. The dynamic track squeeze is determined within a single disc revolution. The read head is positioned half way between two servo tracks. Positioning information for track following is obtained from either track as one disc revolution is completed. During the disc revolution, position measurement is simultaneously collected from both tracks. The difference between the position measurements from each track, which represents the dynamic track squeeze between the two tracks, is determined. An appropriate ZAP correction factor is determined and written to the servo sector of the desired track. The ZAP correction factor is input to the disc drive servo controller and eliminates the dynamic track squeeze.

Abstract: A hard disk drive that determines a saturation current of a voice coil motor (VCM) during the acceleration portion of a seek operation, and uses the information to advantageously adjust current profile for subsequent portion of the seek. One example of determining the saturation current is utilization of the peak value of the saturated acceleration current whose magnitude depends on operating conditions such as temperature and supply voltage. Traditional hard disk drives use predetermined seek current profiles that are formed conservatively to account for such variations in the available current to the VCM, at the expense of sacrificing some seek performance. By determining the available current for each seek operation, the current profile can be adjusted on the fly so as to improve the seek performance.

Abstract: A magnetic disk drive system having a write head Hw and a read head Hr which can move over a magnetic disk in a radial direction of the disk and are arranged at a distance from each other. At a predetermined write start timing tWG, it writes measurement information by the write head in a specific sector at a first timing tW, then reads the information by the read head, detects predetermined positional information included in the information, and produces a second timing tDA. The system subtracts the interval between the second timing and the start timing from the interval between the first timing and second timing to measure the write/read head distance time difference in the track direction of the magnetic head unit. The write/read head distance information is used for correction and control of the operation of the magnetic head unit.

Abstract: An apparatus and a process for positioning a read/write head in a hard disk drive, and more particularly for using the phenomenon of repeatable run-out to efficiently compensate a servo loop used for positioning the head, is provided. The apparatus includes a processor and a read/write channel for a hard disk drive, wherein the processor is configured to calculate repeatable run-out values using position-error-signal (PES) values. The position-error-signal values are contained within an original servo wedge, which is stored on a disk medium. The original servo wedge includes a sync field, an identification field, and at least one position error field. The identification field includes a sync-mark. The processor is configured to use the at least one set of repeatable run-out values to generate a new servo wedge containing updated position information such that the actuator current is minimized. The processor is also configured to cause the new servo wedge to be written to the disk medium.

Abstract: A lateral tape sensor for a tape drive having a tape head that is not capable of moving vertically as quickly as tape media, wherein the sensor senses lateral movement of tape media as it moves along a tape path between a storage reel and a take-up reel. The lateral tape motion sensor comprising a means for sensing the position of at least one edge of the tape media and a means for comparing the at least one edge position to predetermined thresholds to determine if the tape media moved laterally. When the lateral movement exceeds predetermined thresholds, the tape drive processor and control circuits respond to prevent accidentally overwriting data previously written on an adjacent track during a write operation, to adjust the tape head to locate data being read following lateral tape motion that occurs during a read operation or to warn the user of poor tape media quality.

Abstract: Disclosed is an apparatus for recording and reproducing information and an information reproducing method in which the reproducing operation can be restarted from a position where reproduction was interrupted. The restart is possible for all of information contents recorded on a recording medium and without the need of troublesome operations. For this purpose, reproduction history information representing a reproduction history of each of the information contents recorded on the recording medium is stored in a management memory.

Abstract: A slider for use in a disc drive system that is comprised of a trailing edge, a connection for applying a voltage to the slider, an actuation surface for providing electrostatic control, and a recessed area between the trailing edge and the actuation surface. Applying voltage to the slider provides a method for controlling fly height between the trailing edge of the slider and the disc.

Abstract: Apparatus and method for reducing nonlinearities in a position error signal (PES) of a disc drive data handling system. The disc drive data handling system includes a disc recording surface having a number of tracks and a controllably positionable read/write head. A servo circuit generates a sequence of PES samples indicative of head position with respect to a selected track using servo position data samples transduced from the selected track and a first set of compensation values selected to reduce nonlinearities in said PES samples. The PES samples are combined with the first set of compensation values to generate an updated set of compensation values. This process is preferably repeated a number of iterations to converge to a final set of compensation values which provide a substantially linear PES across the radial width of each track.

Abstract: A method of, apparatus for, and means for controlling pitch of a servowritten track on a disc in a disc drive are disclosed. The disc drive has a head for traversing over a surface of the disc. The head has a read element and a write element separated by a head element offset &Dgr;. A servowriting controller operably connected to the disc drive creates a track k by writing servo information on the disc. The servowriting controller then calculates the head element offset &Dgr; at the track k, [&Dgr;CALC(k)] and determines a skew angle &thgr; at the track k, [&thgr;(k)]. The servowriting controller adjusts a track pitch correction factor based on the &Dgr;CALC(K) and the &thgr;(k) such that the track pitch correction factor is utilized to servowrite a next track.

Abstract: An attenuating filter for the servo control processor of a disc drive data storage device. The filter is constructed by determining the peak resonance in the structure frequency response above a preselected magnitude and computing a digital notch filter to attenuate that peak resonance. The notch filter domain is then summed with the structure frequency response to derive a modified structure frequency response. The modified structure frequency response is substituted for the unfiltered structure frequency response and again the peak resonance in the modified structure frequency response above a preselected magnitude is determined and a notch filter is computed as necessary. This process of summing the structure frequency response with the latest computed notch filter domain to derive a modified structure frequency response continues until the peak resonance of the latest modified structure frequency response is less than the preselected magnitude.

Abstract: A method and apparatus are disclosed which allow for compensation of repeatable runout in a disk drive when an actuator arm assembly has a relatively high friction to inertia ratio in a pivot bearing assembly. The compensation uses one of two initial runout coefficients, based on a seek length. If the seek length is shorter than a predetermined distance, a current runout coefficient is used to compensate for repeatable runout which is continuously updated throughout a previous seek operation. If the seek length is greater than the predetermined distance, a transient runout coefficient is used to compensate for repeatable runout which is updated following the initial revolutions of the hard disk.

Abstract: A microactuating suspension assembly used for a disc drive is disclosed. The microactuating suspension assembly has a suspension load beam and a microactuator placed on the suspension load beam for bending the suspension load beam at the front end thereof during a sustained period of data read/write time and thus achieving a desired average fly-height which is different from an unaltered average fly-height which would have been achieved without the microactuator. In particular, the microactuating suspension assembly can be used to achieve a very low fly-height. Additionally, very large bandwidth and very short seeking time is made possible when a bimorph piezoelectric microactuator is used.

Abstract: A method and apparatus for unlatching a VCM in a disc drive is provided in which a determination is made if the VCM is stationary. A first unlatch current pulse that has a first amplitude and first width is applied to the VCM if the VCM is found to be stationary. An incremented unlatch current pulse is then applied to the VCM if the VCM is found to be stationary after application of the first unlatch current pulse. The incremented unlatch current pulse has at least one of an amplitude and a width that is greater than at least one of the corresponding first amplitude and the first width of the first unlatch current pulse.

Abstract: A system and method to minimize the contribution of head channel spacing to the negative effects of transverse changes in dimensions of recording media having prerecorded servopositioning tracks. Multiple channels on the recording head are separated into multiple groups of head channels, and each group of heads is independently positioned relative to the pre-written servo tracks. The head comprises an actuator for each pair of head groups. The actuator adjusts the relative spacing between members of the pair in response to position error signals indicating misalignment between the heads and the pre-written servopositioning tracks on the medium.

Abstract: According to the invention, techniques for cleaning a rotary magneto-resistive head. Embodiments according to the invention are especially useful in tape drive systems, and the like. Embodiments can provide methods and apparatus for cleaning contaminant from rotary magneto-resistive heads while guarding against damage to the head from excess cleaning, and the like. Specific embodiments can control the rotational speed of a rotary magneto-resistive head in order to facilitate cleaning operations. Embodiments include a cleaning device and a control method, and are suited for use in a magneto-resistive head mounted on a rotary cylinder of a computer tape storage unit, for example, although application of the present invention is not limited to such embodiments.