Abstract: A method for accurately adjusting skew in the presence of tape motion includes performing a calibration run of magnetic tape in a tape drive. During the calibration run, the method records skew readings at selected intervals. The method then finds a range associated with the skew readings, such as by finding a high and low skew reading. The method then finds a center point of the range, and a difference between the center point and a desired center point. The method applies the difference to each recorded skew reading to generate a target skew reading for each recorded skew reading. The method generates a skew error signal that reflects the difference between each recorded skew reading and each corresponding target skew reading. The skew error signal will generally be consistent even as the tape moves, thereby allowing a technician to easily adjust and optimize the skew.

Abstract: Methods for formatting and using a linear magnetic recording medium. The medium in one embodiment has a servo band having a width b that is less than or equal to about 1.2 B/N, where N is an integer greater than or equal to 2, and B corresponds to a distance between data read/write transducers of a magnetic head usable with the medium in a direction transverse to a longitudinal length of the medium.

Abstract: Magnetic storage tape and techniques for erasing and writing to magnetic storage tape having a perpendicular squareness greater than 50 percent and a longitudinal squareness less than 50 percent are described. In general, the magnetic tape may be biased with a remanence magnetization, or magnetic orientation, in any direction. One or two head systems may use various magnetic field patterns to create the desired remanence magnetization. Servo marks may have a remanence magnetization in an opposite magnetic orientation than that of the remaining bias on the servo track, e.g., substantially perpendicular to the magnetic tape. In some examples, a write head may alternate the direction of the magnetic field to continuously bias and write servo patterns to the magnetic tape. In addition, a symmetrical servo mark may be created in the magnetic tape with a write head having a gap width approximately equal to the length of the servo mark.

Abstract: In at least one embodiment, a data storage system is provided. The system includes a controller that is configured to determine a direction of current flow to a first write element to write first data on a magnetic tape and to determine a direction of current flow to each of a plurality of neighboring write elements to write corresponding data on the magnetic tape. The controller is further configured to compare the direction of current flow to the first write element to the direction of current flow to the plurality of neighboring write elements. The controller is further configured to control the first write element to write the first data in response to comparing the direction of current flow to the first write element to the direction of current flow to each of the neighboring write elements.

Abstract: An assembly comprises a plurality of laterally spaced front blocks, a magnetic post coupling each of the front blocks to a common back bar, and a common front bar magnetically coupled to the back bar. A write gap spacer is positioned between the front bar and each of the plurality of front blocks, and a write gap element comprising write gaps couples the front bar to each front block across the write gap spacer. A coil is configured to generate magnetic flux in each magnetic post, and the front blocks are configured to direct the magnetic flux across the write gaps.

Abstract: Magnetic storage tape and techniques for erasing and writing to magnetic storage tape having a perpendicular squareness greater than 50 percent and a longitudinal squareness less than 50 percent are described. In general, the magnetic tape may be biased with a remanence magnetization, or magnetic orientation, in any direction. One or two head systems may use various magnetic field patterns to create the desired remanence magnetization. Servo marks may have a remanence magnetization in an opposite magnetic orientation than that of the remaining bias on the servo track, e.g., substantially perpendicular to the magnetic tape. In some examples, a write head may alternate the direction of the magnetic field to continuously bias and write servo patterns to the magnetic tape. In addition, a symmetrical servo mark may be created in the magnetic tape with a write head having a gap width approximately equal to the length of the servo mark.

Abstract: Techniques to determine particular bad tapes or tape drives. All tape and tape drive combinations within a system may be obtained. A read error or a write error that occurs with each tape and tape drive combination may be detected, and the read error, the write error, or a parameter may be analyzed to determine the particular tape or the particular tape drive that is bad.

Abstract: Aspects of the present invention relate to an apparatus and corresponding method that includes transitioning from a monitor state to a stop write state when a determined position error is greater than a threshold error value for a first predetermined period, and transitioning from the monitor state to a write state when the determined position error is less than the threshold error value for a second predetermined period. Write operations are enabled and signals are provided to operate an actuator to translate a magnetic head laterally in a manner to reduce the determined position error while in the write state. Write operations are disabled and signals are provided to operate the actuator to translate the magnetic head laterally in a manner to reduce the determined position error while in the monitor state. Write operations are disabled while in the stop write state.

Abstract: In a controller of a tape drive, a CM input-output unit recognizes a tape format; a tape variable acquisition unit acquires tape variables; a setting variable acquisition unit acquires setting variables; and a minimum number calculator calculates a minimum number m of sub datasets, which are to be written to a tape to secure resistance to burst error, by using the tape variables and setting variables. When a command processor receives a synchronization command, the buffer manager generates n sub datasets for storing data in the buffer. If n is smaller than m, m sub datasets are padded out and set as write data. If n is m or more, the n sub datasets are set as write data. Then, the channel input-output unit writes the write data to the tape.

Abstract: An apparatus and method for providing adaptive disturbance compensation with multi-rate synchronized sampling is disclosed herein. The dynamic disturbance occurring in a media drive during read/write operations is attenuated using the adaptive disturbance compensation scheme. A plurality of compensation filters are used, each of the compensation filters configured to attenuate a disturbance caused by a particular source within the media drive. Each of the compensation filters is computed based on a sampling rate relevant to the respective disturbances.

Abstract: In one general embodiment, a system includes a module having multiple transducers; and a sizing mechanism for actively applying a force to at least one lateral side of the module for selectively compressing the module, thereby adjusting a pitch between the transducers, wherein the lateral side of the module intersects an axis of the module oriented parallel to the direction of the force. Additional systems and methods are also presented.

Abstract: Tape media life is increased by dynamically controlling a turn around point (TAP) on the tape media for either an end of a tape wrap or a directional change from a first longitudinal position tape section to a second longitudinal position tape section for reducing damage to the tape media caused by debris by monitoring the TAP for all tape media motion and adjusting tape deceleration for maintaining the TAP to be located at the second longitudinal position tape section.

Abstract: Magnetic storage tape and techniques for erasing and writing to magnetic storage tape having a perpendicular squareness greater than 50 percent and a longitudinal squareness less than 50 percent are described. In general, the magnetic tape may be biased with a remanence magnetization, or magnetic orientation, in any direction. One or two head systems may use various magnetic field patterns to create the desired remanence magnetization. Servo marks may have a remanence magnetization in an opposite magnetic orientation than that of the remaining bias on the servo track, e.g., substantially perpendicular to the magnetic tape. In some examples, a write head may alternate the direction of the magnetic field to continuously bias and write servo patterns to the magnetic tape. In addition, a symmetrical servo mark may be created in the magnetic tape with a write head having a gap width approximately equal to the length of the servo mark.

Abstract: In one embodiment, a linear magnetic recording tape includes at least one servo band having a servo pattern readable by a servo reader of a magnetic head for positioning thereof, wherein the servo pattern is adapted to substantially fill a width b of the servo band, the servo band width h is less than or equal to about 1.2 B/N, N is an integer greater than or equal to 2, and B corresponds to a distance between data read/write transducers of the magnetic head in a direction transverse to a longitudinal length of the tape. In another embodiment, a method includes providing the linear magnetic recording tape, formatting the tape, and positioning the magnetic head within a first lateral tape region. Other linear magnetic tapes, systems, and methods are described according to other embodiments.

Abstract: In one embodiment, a tape drive system includes a magnetic head having at least one servo sensor for track-following at least one defined servo track of a longitudinal tape, a tape motion controller configured to move the longitudinal tape past the magnetic head, a compound actuator configured to translate the magnetic head laterally with respect to the longitudinal tape, and a control configured to track-follow the at least one defined servo track by reducing a position error between the magnetic head and a desired position, transition from a write state to a monitor state when the position error is greater than a threshold, transition from the monitor state to a stop write state when the position error is greater than the threshold for a first period, and transition from the monitor state to the write state when the position error is less than the threshold for a second period.

Abstract: A tape edge sensor system for detecting lateral movement of a storage tape includes a first photo-emitter, a first photo-detector positioned to receive a first light signal from the first photo-emitter, a first aperture disposed between the first photo-emitter and the first photo-detector, and a feedback system connected to the first photo-emitter and the first photo-detector. The first aperture defines a first region at a first tape edge through which the first light signal is received by the first photo-detector with the storage tape blocking a portion of the first light signal. The feedback system determines the first photo-detector's signal amplitude and adjusts the first light signal such that the first photo-detector signal amplitude is within a first average amplitude range. A tape edge sensor system using compensating photo-interrupters is also provided.

Abstract: A method and apparatus for bipolar and self DC-erase write of servo marks. The method includes providing a servo write head having first and second write gaps; and applying a varying current to the servo write head to alternately DC-erase and write sets of servo marks to regions of a servo track of a magnetic storage medium proximate the first and second write gaps, the magnetic storage medium moving with respect to the first and second write gaps. The apparatus includes a bipolar servo erase/write driver configured to generate both negative and positive polarity currents and to generate a varying bipolar current signal and a servo write head having a first write gap and second write gap spaced apart and where the servo write head is an only means for writing servo marks to the magnetic storage medium and for DC-erasing the servo tracks.

Abstract: A servo system according to one embodiment includes a servo control configured to: determine position error between a magnetic head and a desired position related to at least one defined servo track on a longitudinal tape based on at least one servo signal; calculate a first average position of the magnetic head while the longitudinal tape is moved in a first direction; calculate a first offset of the magnetic head while the longitudinal tape is moved in the first direction based on a target position and an assumption that the first average position of the magnetic head occurred when the tape was at a top-most position or a bottom-most position of a supply reel; and operate an actuator to position the actuator substantially at the target position using the first offset and the first average position.

Abstract: Aspects of the present invention relate to an apparatus and corresponding method that includes transitioning from a monitor state to a stop write state when a determined position error is greater than a threshold error value for a first predetermined period, and transitioning from the monitor state to a write state when the determined position error is less than the threshold error value for a second predetermined period. Write operations are enabled and signals are provided to operate an actuator to translate a magnetic head laterally in a manner to reduce the determined position error while in the write state. Write operations are disabled and signals are provided to operate the actuator to translate the magnetic head laterally in a manner to reduce the determined position error while in the monitor state. Write operations are disabled while in the stop write state.

Abstract: Described are embodiments of an invention for customizing the range of acceptable write conditions to a tape of a tape cartridge that contracts or expands laterally based on environmental conditions. The tape drive utilizes servo information to determine if the tape has expanded or contracted from the nominal dimension and to determine the magnitude of the expansion or contraction. In the case of expansion, the magnitude of the determined expansion and the stored maximum amount of contraction must be below a predetermined threshold value to allow a write. In the case of contraction, the magnitude of the determined contraction and the stored magnitude of expansion must be below the same predetermined threshold value to allow a write. If the determined magnitude of contraction or expansion is greater than the stored magnitude of contraction or expansion, respectively, then the new extreme is stored.

Abstract: A method, system, apparatus, and computer readable medium storing instructions for recording data tracks and a method and system for reading data tracks. For recording data tracks, virtual boundary of a first data track recorded on the storage medium is determined. The recording element is positioned based on the determined virtual boundary of the first track and a second data track is recorded by the positioned recording element. For reading data tracks, a first virtual boundary of a first data track and a second virtual boundary of the first data track are determined and a reading element is positioned at a center of the first data track based on the determined virtual boundaries. In the system of reading recorded data tracks, a number of forward reading elements and backward reading elements are provided. The forward reading elements have different pitches.

Abstract: A tape drive (232) that receives a tape cartridge (42) having a tape (256) comprises a tape head (280) and a control system (270). The tape head (280) transfers data between the tape drive (232) and the tape (256). The control system (270) utilizes linear parameterization to control the position of the tape head (280) relative to the tape (256). The control system (270) can include a compensator (J) and a filter (Q). The compensator (J) is a combination of the information contained in a nominal control system (370A) and the information contained in a model of the servo system (370B). The model of the servo system (370B) estimates system disturbances that affect the tracking ability of the control system (270). The filter (Q) filters the estimated system disturbances to generate a filtered system disturbance signal. The filtered system disturbance signal is then used to adjust the output of the compensator (J).

Abstract: In a controller of a tape drive, a command processing unit receives a request to write new data, an offset determination unit determines whether old data is not partially overwritten with new data, and if old data is not partially overwritten with new data, a head position management unit makes a write head offset toward the unoverwritten portion. Then, a channel input/output unit reads pattern data that disables old data from a pattern storage unit and outputs the data to the write head to thereby overwrite the old data with the pattern data. After that, a tape transport management unit rewinds a tape and the head position management unit returns the write head to the original position to overwrite the old data with the new data as usual.

Abstract: According to one embodiment, a method includes sensing a first servo sensor while a longitudinal tape is moved in a first direction; determining position error between the magnetic head and a desired position related to the at least one defined servo track; providing signals to operate a fine actuator to translate the magnetic head laterally in a manner to reduce the determined position error; calculating a first average position of the magnetic head for at least one first run-out cycle while the longitudinal tape is moved in the first direction; calculating a first offset of the magnetic head while the longitudinal tape is moved in the first direction; operating a coarse actuator to position the coarse actuator substantially at a target position using the first offset and the first average position.

Abstract: A method according to one embodiment includes selecting an initial radius value (Rfull) for an outgoing reel, where Rfull is the initial radius of a tape on the outgoing reel; unwinding the tape from the outgoing reel; computing a radius value of the tape on the outgoing reel during the unwinding; adjusting the computed radius with an offset calculated from a direct measurement of velocity from the tape position; and outputting the adjusted computed radius. A method according to another embodiment includes selecting an initial radius value (R0) for an incoming reel, where R0 is the initial radius of the incoming reel; winding the tape onto the incoming reel; computing a radius value of the tape on the incoming reel during the winding; adjusting the computed radius with an offset calculated from a direct measurement of velocity from the tape position; and outputting the adjusted computed radius.

Abstract: A maximum velocity is dynamically determined during a tape drive operation to obtain a statistical standard deviation of a position error signal (PES) that yields an amount of stopwrite (SW) operations that avoids backhitching. The tape velocity is adjusted to the maximum velocity.

Abstract: Controlling positions of storage media heads is disclosed. An example storage media head position controller includes a position error filter to filter a media head position error based on a target position for a storage media head relative to a storage medium and a present media head position to generate a position signal, and a media speed monitor to modify an integration factor in the position error filter based on a media speed to adjust a phase margin of the position control loop.

Abstract: A partitioning format for magnetic tape media that includes at least a first portion (e.g., a file directory) having a plurality of dynamically updateable (e.g., non-shingled) partitions and a second portion (e.g., a data portion) having a plurality of linearly or sequentially written shingled partitions. Use of both shingled and non-shingled partitions on the same length of magnetic tape allows for an increase in capacity over those applications that perform linear recording of non-shingled partitions while allowing for the dynamic updating of a local file directory free of disturbing the linearly written data of the shingled partitions.

Abstract: A tape drive is disclosed. The tape drive determines a current tape width and adjusts the length of a tape head to more closely match the current tape width. The tape drive adjusts the length of the tape head by controlling the power to a heating element coupled to the tape head.

Abstract: A servo track has servo pattern frames including two pairs of parallel transitions, the transitions of each pair spaced apart an equal distance, the first pair at an azimuth angle, the second pair at the opposite azimuth angle. A servo channel receives signals at first times corresponding to a servo read head detecting the transitions of the first pair of parallel transitions of a servo pattern frame, and second times corresponding to the servo read head detecting the transitions of the second pair of parallel transitions. The servo channel determines a relative lateral movement and velocity between the tape and the tape head based on respective functions of the ratio (TD?TC)/(TB?TA), distance d, and constants proportional to the azimuth angle and the trajectory angle.

Abstract: A system provides tape having at least one longitudinal data track and a tape head operative to move along a single axis line lateral to the data track. The storage tape moves across the tape head. The tape head moves along the axis line such that a write element of the tape head intersects the data track and writes data to a section of the data track. A controller determines that the storage tape is skewed. In response to determining that the storage tape is skewed, the controller determines a position along the axis line and a time to move the tape head such that the read elements intersects the section of the data track. At the determined time, the tape head pauses writing of data and moves to the position along the axis line. The tape head reads the section of the data track to verify the written data.

Abstract: A servo track has identical servo pattern frames including two pairs of parallel magnetic transitions, the transitions of each pair spaced apart an equal distance, the transitions of the first pair at an azimuth angle to the longitudinal axis of the tape, the transitions of the second pair at an opposite azimuth angle. A servo channel receives signals at first times corresponding to when a servo read head detects the first and second transitions of the first pair of parallel transitions of a servo pattern frame, and second times corresponding to when the servo read head detects the first and second transitions of the second pair of parallel transitions. The servo channel determines a relative lateral movement and velocity between the tape and the tape head based on the azimuth angle and the ratio of the difference of the first and the difference of the second times.

Abstract: A magnetic tape apparatus performs at least one of data reading processing and data writing processing on LTO wound around a reel. The magnetic tape apparatus causes the reel to rotate and move the LTO to a position at which the data writing processing or the data reading processing can be performed by a magnetic head. The magnetic tape apparatus is arranged along the width direction of the magnetic tape of LTO, which is driven, to detect medium abnormality that occurred in either a start-end or a stop-end in the width direction of the magnetic tape.

Abstract: A servo track has identical servo pattern frames including two pairs of parallel magnetic transitions, the transitions of each pair spaced apart an equal distance, the transitions of the first pair at an azimuth angle to the longitudinal axis of the tape, the transitions of the second pair at an opposite azimuth angle. A servo channel receives signals at first times corresponding to when a servo read head detects the first and second transitions of the first pair of parallel transitions of a servo pattern frame, and second times corresponding to when the servo read head detects the first and second transitions of the second pair of parallel transitions. The servo channel determines a relative lateral movement and velocity between the tape and the tape head based on the azimuth angle and the ratio of the difference of the first and the difference of the second times.

Abstract: Disclosed herein are aspects of optical tape technology, tape manufacturing, and tape usage. Methods and systems of tape technology disclose optical tape media including: configurations, formulations, markings, and structure; optical tape manufacturing methods, systems, and apparatus methods and systems including: curing processes, coating methods, embossing, drums, testing, tracking alignment stamper strip; optical tape methods and systems including: pick up head adapted for the disclosed optical tape; and optical tape uses including optical storage media devices for multimedia applications.

Abstract: A tape drive configured to accurately position a head actuator in the presence of physical disturbances is disclosed. The tape drive includes a track-follow controller to position a head actuator over data tracks on magnetic tape. The tape drive further includes a disturbance observer configured to estimate a vibration disturbance and output a compensation signal to assist the track-follow controller to accurately position the head actuator over the data tracks in the presence of vibration. When estimating the vibration disturbance, the disturbance observer takes into account vibration frequency characteristics, such as frequency characteristics derived from a vibration specification associated with the tape drive, or frequency characteristics derived from known vibration disturbances experienced by the tape drive. A corresponding method is also disclosed.

Abstract: A tape drive system according to one embodiment includes a magnetic head having at least one servo sensor; a tape motion controller; a fine actuator; a skew actuator; a coarse actuator; and a control. The control is configured to perform various operations that help account for vibrations that effect track-following a servo track when operating a tape drive. Additional systems, methods and computer program products are also described.

Abstract: There is described apparatus (800) to decode longitudinal position (LPOS) information from non-shifted servo elements (a1, a4, a7) and an unbroken sequence of plural shifted servo elements (a2-a3, a5-a6), variations in the relative displacement of the non-shifted and shifted elements encoding the LPOS information. The apparatus is operable to receive signals (905) from a transducer head apparatus (131) that detects the servo elements as they move past the transducer head apparatus, and to process the signals to obtain data (L1, L4, L5, L8) related to relative displacement of mutually adjacent shifted and non-shifted elements within respective ones of the servo bursts, and data (L2, L3, L6, L7) related to relative displacement of mutually non-adjacent shifted and non-shifted elements within the respective ones of the servo bursts, and also to process the data to determine LPOS bit values corresponding to the respective ones of the servo bursts.

Abstract: A magnetic tape drive has a drive system to move a magnetic tape longitudinally; servo head(s) for reading servo band information from a magnetic tape as the magnetic tape is moved longitudinally; a magnetic tape read write head configured to read and to write the magnetic tape, having a data write width (w) greater than a normal shingled track pitch width (p) of the magnetic tape; an actuator system for positioning the read write head laterally; and a control. The magnetic tape drive stores an overwrite erase format of non-shingled track pitch longitudinal pattern(s) whose pitch is greater than the normal shingled track pitch width (p); and, the control, in response to activation of overwrite erasure of the tape drive, operates the actuator system and the magnetic tape read write head to write non-data to magnetic tape in the stored overwrite erase format.

Abstract: Method for operating a storage device with a tape and a head wherein the head comprises a first and a second read element. Each read element is operable to detect servo-pattern of a particular servo band. The first and the second read element are arranged such that the tape at first passes one of both read elements and subsequently passes the other of both read elements when the tape moves in a predetermined longitudinal direction. A tape transport direction of the tape along the longitudinal direction is determined. The first read element is selected dependent on the determined tape transport direction, when the determined tape transport direction represents a direction where the tape at first passes the first read element and subsequently the second read element. Otherwise the second read element is selected. A position error signal is determined dependent on the selected read element.

Abstract: Disclosed is a method of storing data on a tape medium in at least one data recording session employing a tape drive apparatus operable to record the data in accordance with a format specifying an unused area of the tape medium. The method comprises formatting the tape medium according to the format, and recording a tape medium identifier in the specified unused area of the tape medium.

Abstract: In one embodiment, a tape drive system includes a magnetic head having a servo sensor for sensing a defined servo track of a magnetic tape and configured to read servo pulses from servo bursts of the servo track while the magnetic tape is moving past the magnetic head with the servo bursts representing an encoded data symbol, an analog-to-digital converter configured to provide a sequence of samples of the readback servo signal, a digital correlator configured to compute a correlation signal between the sequence and a reference waveform, a timing reference module configured to provide a reference timing model having interpolation instants to the digital correlator, a correlation interpolator configured to interpolate the correlation signal at the interpolation instants and compute a longitudinal position (LPOS) detection metric, and an LPOS detector configured to decode the encoded data symbol of the servo bursts using the computed LPOS detection metric.

Abstract: A servo system according to one embodiment includes a servo control configured to: determine position error between a magnetic head and a desired position related to at least one defined servo track on a longitudinal tape based on at least one servo signal; calculate a first average position of the magnetic head while the longitudinal tape is moved in a first direction; calculate a first offset of the magnetic head while the longitudinal tape is moved in the first direction based on a target position and an assumption that the first average position of the magnetic head occurred when the tape was at a top-most position or a bottom-most position of a supply reel; and operate an actuator to position the actuator substantially at the target position using the first offset and the first average position

Abstract: A servo signal in which a magnetic pattern composed of a first portion magnetized in one direction that is one of two opposite thickness directions and a second portion magnetized in a direction opposite to the one direction is repeatedly arranged in a longitudinal direction of the tape at predetermined intervals is read out and a waveform of the servo signal is acquired from the readout servo signal. In the acquired waveform of the servo signal, a unit waveform having a pair of peaks of opposite polarities corresponding to the magnetic pattern appears periodically. A crest or trough portion of the waveform containing one of the peaks located rearwardly in the tape transport direction in a time of writing the servo signal is selected from the unit waveform contained in the acquired waveform of the servo signal. Tracking control or servo signal verification is performed based on the selected portion.

Abstract: A servo system according to one embodiment includes at least one servo sensor for sensing a lateral position of a magnetic head with respect to at least one defined servo track of a longitudinal tape; a fine actuator configured to translate the magnetic head laterally with respect to the longitudinal tape; a coarse actuator configured to translate the fine actuator laterally with respect to the longitudinal tape; and a servo control. The servo control is configured to perform various operations that may be used to estimate a midpoint of lateral tape excursion of a flangeless tape path for calibrating a tape drive. Additional systems are also presented.

Abstract: In one embodiment, a method includes sensing a servo sensor while a longitudinal tape is moved past a magnetic head, determining position error between the magnetic head and a desired position related to the at least one defined servo track; providing signals to operate a fine actuator to translate the magnetic head laterally in a manner to reduce the determined position error; transitioning from a write state to a monitor state when the determined position error is greater than a threshold error value; transitioning from the monitor state to a stop write state when the determined position error is greater than the threshold error value for a first predetermined period; and transitioning from the monitor state to the write state when the determined position error is less than the threshold error value for a second predetermined period.

Abstract: In a controller of a tape drive, a command processing unit receives a request to write new data, an offset determination unit determines whether old data is not partially overwritten with new data, and if old data is not partially overwritten with new data, a head position management unit makes a write head offset toward the unoverwritten portion. Then, a channel input/output unit reads pattern data that disables old data from a pattern storage unit and outputs the data to the write head to thereby overwrite the old data with the pattern data. After that, a tape transport management unit rewinds a tape and the head position management unit returns the write head to the original position to overwrite the old data with the new data as usual.

Abstract: A thin film magnetic recording head is fabricated by forming a substrate from opposing ferrite blocks which have a ceramic member bonded between them. This structure is then diced to form a plurality of columns, wherein each column has a ferrite/ceramic combination. Each column represents a single channel in the completed head. A block of ceramic is then cut to match the columned structure and the two are bonded together. The bonded structure is then cut or ground until a head is formed, having ceramic disposed between each channel. A ferrite back-gap is then added to each channel, minimizing the reluctance of the flux path. The thin film is patterned on the head to optimize various channel configurations.

Abstract: An apparatus includes plural spaced apart sensors arranged along a direction of motion of a medium, and a processing circuit to receive signals from the sensors, determine a difference of the signals, and identify an error built into the medium based on the difference.

Abstract: A pulse mismatch is measured for servo stripes on magnetic tape written with a servo write head having servo head gaps with different physical sizes. The servo head gaps are separately energized to correct the pulse mismatch so servo stripes written on the magnetic tape are within a predefined tolerance.