Patent application number | Description | Published |
20080219134 | Method for Positioning a Scanning Probe on a Target Track of a Multi-Track Storage Medium, Storage Device, Scanning Device, and Storage Medium - A method for settling on a target track of a servo system in a storage device ( | 09-11-2008 |
20080225677 | Storage device having flexible architecture and free scalability - A storage device according to the invention has flexible architecture and free scalability. It includes an address input and a data input. It also includes an address and data evaluation unit, which is formed in such a way that it controls a controllable switching means, wherein in operation the address and data evaluation unit depends on the signals of said address and data inputs. Finally, a read/write line for a read/write signal is provided, which can be applied to a local probe data storage unit via the controllable switching means. | 09-18-2008 |
20080304379 | Writing and Reading of Data in Probe-Based Data Storage Devices - Methods and apparatus are provided for controlling writing and reading of data in an array of A storage fields of a probe-based data storage device in which data is written to and read from the array of storage fields by a corresponding array of probes. One method uses the concept of sub-arrays to provide variable-rate read/write operation. Input data blocks are received for writing to the A-field array, each input data block being writable in A/k | 12-11-2008 |
20080316905 | Data Storage Device - A storage device including a storage medium for storing data in the form of topographic or magnetic marks. At least one probe is mounted on a common frame, the common frame and the storage medium designed for moving relative to each other for creating or detecting said marks. Each probe includes a tip facing the storage medium, a read sensing element, a write element and a capacitive platform, that forms a first electrode and is designed for a voltage potential applied to it independent from a control signal for said read sensing element and for said voltage potential applied to said capacitive platform being independent from a control signal for said write heating element. It further comprises a second electrode arranged in a fixed position relative to the storage medium forming a first capacitor together wherein said first electrode and a medium between the first and second electrode. | 12-25-2008 |
20090002869 | POSITIONING OF PLANTS IN SERVO SYSTEMS - Apparatus is provided for fast-adjustment of the position of a plant in a servo system in which a servo output indicative of the plant position is provided to a positioning system for positioning the plant in dependence on the servo output. The apparatus includes an adjustment signal generator, operable in a fast-correction mode and a shock-compensation mode, for generating an adjustment signal for supply to the positioning system to effect fast positional adjustment of the plant. The apparatus also has an adjustment controller for receiving the servo output. The adjustment controller is adapted to detect from the servo output occurrence of a disturbance affecting positioning of the plant and, in response, to initiate the shock-compensation mode of the adjustment signal generator. The adjustment controller is further adapted to initiate the fast-correction mode of the adjustment signal generator in response to indication of an error in positioning of the plant. On initiation of each mode, the adjustment controller supplies an input signal dependent on the servo output to the adjustment signal generator. The adjustment signal generator processes the input signal to generate the adjustment signal such that, in the fast-correction mode the adjustment signal effects adjustment of the plant position to correct the positioning error, and in the shock-compensation mode the adjustment signal effects adjustment of the plant position to counter the effect of the disturbance. | 01-01-2009 |
20090003187 | Storage Device and Method for Operating a Storage Device - A method of operating a storage device includes storing data in the form of marks in a storage medium; scanning the storage medium with at least one probe operating in a scanning mode; and utilizing a control unit to provide a pulsed reading signal for data detecting in the scanning mode, and providing the probe with oversampling reading pulses in a clock mark scanning mode, wherein the control unit further comprises an input for a response signal to the oversampling reading pulses, and a determination unit for determining the clock dependent on the response signal; wherein the storage medium comprises marks for determining a clock of the pulsed reading signal. | 01-01-2009 |
20090174964 | SERVO CHANNEL FOR TAPE DRIVE SYSTEMS - Provided are techniques for synchronous servo channel for a data tape drive. A servo reader is configured to read servo bursts from a data tape. An anti-aliasing filter is operable to output a bandlimited signal and is coupled to receive a servo channel signal comprising servo bursts from the servo reader. An analog-to-digital converter (ADC) is operable to output signal samples and is coupled to receive the bandlimited signal from the anti-aliasing filter. An interpolation and control unit is operable to output interpolated signal samples and control signals, has a first input coupled to receive the signal samples from the ADC, and has a second input coupled to receive the correlation signal samples from the dibit correlator. A dibit correlator is operable to output correlation signal samples and is coupled to receive the interpolated signal samples and control signals from the interpolation and control unit. | 07-09-2009 |
20090237832 | ERROR CORRECTION CODING OF LONGITUDINAL POSITION INFORMATION - A sequential data storage medium, comprising a sequence of plurality of servo patterns that provide lateral position information and longitudinal position information, wherein each of the plurality of servo patterns comprises a first burst comprising a first plurality of pulses, a second burst comprising a second plurality of pulses, a third burst comprising a third plurality of pulses, and a fourth burst comprising a fourth plurality of pulses. The spacings between the first plurality of pulses, in combination with the spacings between the second plurality of pulses, encode a first bit without affecting the recovery of lateral position information. The spacings between the third plurality of pulses, in combination with the spacings between the fourth plurality of pulses, encode a second bit without affecting the recovery of lateral position information. The sequence of plurality of servo patterns comprises a sequence of the first bits and a sequence of the second bits to form an error-correction codeword providing error-correction capability. | 09-24-2009 |
20090279201 | JOINT SPECIFICATION OF SERVO FORMAT AND SERVO READER PARAMETERS FOR TAPE DRIVE SYSTEMS - A servo pattern, including stripes arranged in servo bursts for use in position error signal (PES) generation, is provided in which a stripe width is narrower than 1.7 μm and in which the stripes are oriented at an azimuth angle which in absolute value is equal to or larger than 6 degrees. | 11-12-2009 |
20090279202 | HEAD DESIGN FOR WRITING SERVO PATTERNS ON MAGNETIC TAPE - A servo write head is provided and is configured to simultaneously write at least two servo patterns in respective servo bands on linear magnetic tape. Centerlines of the servo patterns are substantially uniformly spaced in the lateral direction. In addition, the servo patterns of all adjacent respective servo bands are displaced relative to each other in a longitudinal direction by an amount that is related to a length of a servo frame and a type of the servo patterns. | 11-12-2009 |
20100073800 | RECOVERING SERVO INFORMATION FROM A SYNCHRONOUS SERVO CHANNEL - Provided are a method, servo channel, and tape drive for recovering servo information from a synchronous servo channel. An interpolator reads samples of a servo signal obtained from a servo reader at a rate of one servo sample per clock interval, to produce up to M interpolated servo samples per clock interval. A first buffer buffers interpolation time instants at which the interpolator generates interpolated servo samples. The interpolated servo samples are buffered in a second buffer and the interpolated servo samples are outputted from the second buffer to a correlator to produce correlation signal samples. | 03-25-2010 |
20100226037 | COMBINING INFORMATION FROM PARALLEL SERVO CHANNELS - A weighted combining scheme exploits information from two servo channels operating in parallel. A timing-based servo module servo module comprises two servo channels coupled respectively to receive two digital servo signals read from a data tape. Both channels have outputs for an unweighted metric and for a measure of the channel reliability. A weight computation module provides first and second weight signals using the measures of channel reliability from the servo channels. A first multiplying node receives a first unweighted metric and a first weight signal and is operable to output a first weighted metric. A second multiplying node receives a second unweighted metric and a second weight signal and outputs a second weighted metric. A summing node receives the first and second weighted metrics and outputs a combined weighted metric to an LPOS word decoder. | 09-09-2010 |
20100226039 | COMBINING INFORMATION FROM PARALLEL SERVO CHANNELS - A weighted combining scheme exploits information from two servo channels operating in parallel. A timing-based servo module comprises two synchronous servo channels coupled respectively to receive two digital servo signals read from a data tape. Both channels have outputs for an unweighted parameter estimate and for a measure of the channel reliability. A weight computation module provides first and second weight signals using the measures of channel reliability from the servo channels. An offset computation module provides first and second offset terms which are summed with the unweighted parameter estimates. Multiplying nodes receive the unweighted parameter estimates and the weight signals and outputs offset weighted parameter estimates. A summing node receives the offset weighted parameter estimates and outputs a combined offset weighted parameter estimate to a servomechanism. | 09-09-2010 |
20100232047 | DATA INTERLEAVING IN TAPE DRIVES - Methods and apparatus for interleaving data in a multitrack tape drive and for writing data on a multitrack tape in the tape drive. One method includes: partitioning the data into m(2 | 09-16-2010 |
20100328803 | COMBINING INFORMATION FROM PARALLEL SERVO CHANNELS - A weighted combining scheme exploits information from two servo channels operating in parallel. A timing-based servo module comprises two synchronous servo channels coupled respectively to receive two digital servo signals read from a data tape. Both channels have outputs for an unweighted parameter estimate and for a measure of the channel reliability. A weight computation module provides first and second weight signals using the measures of channel reliability from the servo channels. An offset computation module provides first and second offset terms which are summed with the unweighted parameter estimates. Multiplying nodes receive the unweighted parameter estimates and the weight signals and outputs offset weighted parameter estimates. A summing node receives the offset weighted parameter estimates and outputs a combined offset weighted parameter estimate to a servomechanism. | 12-30-2010 |
20110007418 | COMBINING INFORMATION FROM PARALLEL SERVO CHANNELS - A weighted combining scheme exploits information from two servo channels operating in parallel. A timing-based servo module comprises two synchronous servo channels coupled respectively to receive two digital servo signals read from a data tape. Both channels have outputs for an unweighted parameter estimate and for a measure of the channel reliability. A weight computation module provides first and second weight signals using the measures of channel reliability from the servo channels. An offset computation module provides first and second offset terms which are summed with the unweighted parameter estimates. Multiplying nodes receive the unweighted parameter estimates and the weight signals and outputs offset weighted parameter estimates. A summing node receives the offset weighted parameter estimates and outputs a combined offset weighted parameter estimate to a servomechanism. | 01-13-2011 |
20110043945 | SERVOMECHANISM WITH ADJUSTABLE PREDICTOR FILTER - A digital control system, and in particular a tape drive system having a track-following servomechanism with a predictor (also referred to herein as a predictor filter), is described. In certain embodiments, the servomechanism includes an actuator, a servo channel, and a predictor coupled to the servo channel. The predictor receives from the servo channel a lateral position estimate signal and determines a modified lateral position estimate signal that reduces a difference, introduced by a tape velocity-dependent delay, e.g., introduced by the servo channel, between the modified lateral position estimate signal and an actual lateral position. The modified lateral position estimate may be used to modify a control signal sent to the actuator. | 02-24-2011 |
20110102927 | MULTILEVEL PULSE POSITION MODULATION FOR EFFICIENT ENCODING OF INFORMATION INTO SERVO PATTERNS - A storage medium on which servo patterns are encoded to provide lateral and longitudinal position (LPOS) information is provided. Each of the servo patterns includes a servo frame, including first through fourth bursts, which are each independently modulated with multi-level pulse position modulation (PPM) to encode at least one independent bit per burst. | 05-05-2011 |
20110134562 | OPERATING A REEL-TO-REEL SYSTEM - A method for operating a reel-to-reel system of a storage device with a first reel, a second reel, a first motor and a second motor, the first motor drives the first reel and the second motor drives the second reel. The system transports a tape supplied by one of the two reels and taken up by the other reel. A tape velocity and tape tension between the first and reels, and a longitudinal displacement are determined. An estimated state vector depends on the tape velocity, tape tension and longitudinal displacement. A reference state vector depends on a predetermined reference tape velocity and a predetermined reference tape tension. A first control signal and a second control signal are generated dependent on the estimated state vector and the reference state vector. The first motor is controlled by the first control signal and the second motor is controlled by the second control signal. | 06-09-2011 |
20110176237 | MAGNETIC TAPE SERVO FORMAT ALLOWING FOR INCREASED LINEAR TAPE DENSITY AND SYSTEMS THEREOF - According to one embodiment, a magnetic recording tape includes a plurality of servo tracks, each servo track comprising a series of magnetically defined bars having an average height of between about 80 microns and about 120 microns, wherein an average stripe angle of the bars is between about 10° and about 25°. A stripe angle is measured between a longitudinal axis of each respective bar and a line oriented perpendicular to a direction of tape travel and parallel to a plane of the tape, wherein an average stripe width of the bars is between about 1.0 micron and about 2.2 microns and an average servo frame length of groups of the bars comprising a servo frame is between about 120 microns and about 180 microns. In more embodiments, a servo format and a system including a servo format are disclosed, along with other embodiments of magnetic tapes. | 07-21-2011 |
20110205657 | SYNCHRONIZATION OF SYMMETRIC TIMING BASED SERVO BURSTS - Timing based servo bursts of servo frames, in which the frames are arranged to be symmetric with the same number of servo stripes in each burst of a frame, are synchronized by shifting selected bits. For example, servo frames are arranged with four servo bursts with an equal number of servo stripes in each burst, the servo frames comprising two symmetric sub-frames, each sub-frame comprising two bursts of servo stripes that are parallel to each other within a burst, and the bursts are non-parallel with respect to each other; each servo burst is arranged to comprise at least one reference servo stripe; and each servo burst is arranged to comprise at least one shifted servo stripe, wherein the shift is in the same longitudinal direction with respect to at least one reference servo stripe for each burst of a frame and the opposite longitudinal direction for bursts of sequentially adjacent frames. | 08-25-2011 |
20110216434 | TIMING ALTERNATIVE INTERVALS WITHIN A TIMING BASED SERVO BAND - An alternative time interval is taken of a timing based servo band to determine lateral position of a servo read head. The servo band is arranged in a sequence bursts with non-parallel servo stripes in sequentially adjacent sub-frames of a linear tape. The timing intervals comprise at least a first time interval (A) between a first pair of non-parallel servo stripes of a sub-frame; and an alternative time interval (C) between a pair of non-parallel servo stripes intermediate the first time intervals (A), the alternative interval servo stripes of sequentially adjacent sub-frames comprising a second servo stripe of the first pair, and a first servo stripe of a sequentially succeeding first pair. Position signals are ratios involving the first and second time intervals. | 09-08-2011 |
20110267717 | LINEAR RECORDING TAPE WITH A REDUCED SERVO BAND WIDTH, AND SYSTEM AND METHOD FOR USING THE SAME - 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. | 11-03-2011 |
20120014010 | DETERMINING A REFERENCE WAVEFORM USED BY A CORRELATOR IN A SERVO CHANNEL - Provided are a method, servo channel, and tape drive for determining a reference waveform used by a correlator in a servo channel. Sequences of servo signal samples are provided from read servo signals read from a servo pattern on a recording medium. A determination is made of a reference waveform based on the sequences of servo signal samples and the reference waveform is forwarded. Interpolated servo signals are generated. The interpolated servo signal samples and the forwarded reference waveform are received to generate correlation output samples. Position and velocity information are calculated from the correlation output samples. | 01-19-2012 |
20120212852 | DETERMINING A REFERENCE WAVEFORM USED BY A CORRELATOR IN A SERVO CHANNEL - Provided are a method, servo channel, and tape drive for determining a reference waveform used by a correlator in a servo channel. Sequences of servo signal samples are provided from read servo signals read from a servo pattern on a recording medium. A determination is made of a reference waveform based on the sequences of servo signal samples and the reference waveform is forwarded. Interpolated servo signals are generated. The interpolated servo signal samples and the forwarded reference waveform are received to generate correlation output samples. Position and velocity information are calculated from the correlation output samples. | 08-23-2012 |
20120268842 | METHOD AND APPARATUS FOR OPERATING A STORAGE DEVICE - Method for operating a storage device with a tape and a head which is operable to read and/or write data from and respectively to the tape. The tape is moveable in a predetermined longitudinal direction. At least two consecutive current lateral tape positions of the tape with respect to a predetermined reference point are determined at a predetermined longitudinal capture position. A tape skew of the tape is determined dependent on the at least two determined lateral positions. The tape skew represents an angle between a current tape motion direction of the tape and the longitudinal direction. A skew control signal is determined dependent on the determined tape skew. A rotational head position of the head is controlled dependent on the skew control signal to align the head to the current tape motion direction in such a way that the head is operable to read and/or write data. | 10-25-2012 |
20130088794 | ROBUST METRIC COMPUTATION OF LONGITUDINAL POSITION (LPOS) DATA SYMBOL DETECTION - 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. | 04-11-2013 |
20130107393 | LONGITUDINAL POSITION INFORMATION ON A MAGNETIC TAPE MEDIA | 05-02-2013 |
20130179754 | DECODING IN SOLID STATE MEMORY DEVICES - In a solid state memory device, codewords stored in a unit of the memory device are decoded using an error correcting iterative decoding process. An average number of iterations needed for successfully decoding codewords of the unit is determined, and the average number of iterations is monitored. The average number of iterations can be taken as a measure of wear of the subject unit. | 07-11-2013 |
20130222940 | MAGNETIC TAPE SERVO FORMAT ALLOWING FOR INCREASED LINEAR TAPE DENSITY AND SYSTEMS THEREOF - In one general embodiment, a magnetic recording tape includes a plurality of servo tracks, each servo track comprising a series of magnetically defined bars, wherein an average stripe width of the bars is between about 1.0 micron and about 2.2 microns, where an average servo frame length of groups of the bars comprising a servo frame is between about 120 microns and about 180 microns. In another general embodiment, a system includes a head having at least one servo reader and an array of data transducers of a type selected from a group consisting of readers and writers; and a controller operative to selectively enable every other transducer of a particular type in the array in a first mode of operation, and operative to selectively enable every transducer of the particular type in the array in a second mode of operation. | 08-29-2013 |
20130321949 | SERVO CONTROL - A tape head includes a set of one or more segments, wherein each segment of the set is individually movable with respect to a frame; each segment of the set comprising at least one of a write element configured to write data to a tape and a read element configured to read data from the tape; and each segment of the set comprising a further read element having a width transverse to a motion direction of the tape being at least a width of the write element of the segment or, in the event that no write element is comprised in the segment, of a write element of a different segment. | 12-05-2013 |
20140002923 | MAGNETIC TAPE MEDIUM | 01-02-2014 |
20140029130 | METHOD AND APPARATUS FOR OPERATING A TAPE STORAGE DEVICE - In a method for operating a tape storage device comprising a tape head for reading and/or writing data from/to a tape in the tape storage device, a first tape skew value concerning a skew of the tape is determined and the first tape skew value is converted into a first skew control signal by means of a skew feedback controller. A second tape skew value concerning the skew of the tape is determined, and the second tape skew value is converted into a second skew control signal by means of feed-forward controller. At least one compensation signal for the second skew control signal is determined, and at least one of a rotational orientation of the tape head and a tape motion direction of the tape is controlled dependent on the second skew control signal and the compensation signal in case the first skew control signal fails. | 01-30-2014 |
20140036382 | ROBUST METRIC COMPUTATION OF LONGITUDINAL POSITION (LPOS) DATA SYMBOL DETECTION - An apparatus according to one embodiment includes a digital correlator configured to compute a correlation signal between a sequence of samples of a readback servo signal and a reference waveform. A timing reference module is configured to provide a reference timing model comprising one or more interpolation instants to the digital correlator, wherein the correlation signal determined at each interpolation instant yields a detection metric for one data symbol. A correlation interpolator is configured to interpolate the correlation signal at the interpolation instants and compute a longitudinal position (LPOS) detection metric according to the interpolated correlation signal samples. | 02-06-2014 |
20140204483 | SERVO CONTROL - In a method for operating a tape storage system, while a tape is being moved in a tape drive across a tape head for one or more of reading and writing user data from/to a data track of the tape, a read element of the tape head, which read element is assigned to the data track, is moved transverse to a moving direction of the tape for a distance of more than a width of the data track. A transverse position of one or more of the following elements is subject to a signal supplied by the read element during its transverse move: The read element; another read element assigned to the data track; and a write element assigned to the data track. | 07-24-2014 |
20140312154 | CONTROLLING THE TRANSPORT OF A TAPE WITHIN A TAPE TRANSPORT SYSTEM - A control device for controlling the transport of a tape within a tape transport system, the tape transport system having a head being operable to read data from and/or write data to the tape, an outboard reel and an inboard reel, wherein the tape is moveable from the outboard reel to the inboard reel in forward direction or from the inboard reel to the outboard reel in reverse direction, wherein the control device is adapted to generate control signals to control the velocity of the outboard reel and the velocity of the inboard reel as a function of a primary velocity of the tape at the head and a secondary velocity of the tape at the inboard reel and/or a secondary velocity of the tape at the outboard reel. | 10-23-2014 |
20140363699 | CURRENT-PERPENDICULAR-TO-PLANE MAGNETORESISTIVE READ SENSOR - A current-perpendicular-to-plane magnetoresistive read sensor includes a stack of layers extending along a stacking direction, and an edge surface parallel to the stacking direction that forms at least part of a bearing surface of the read sensor, the bearing surface designed to face a recording medium. The stack of layers includes a first contact layer, a ferromagnetic free layer whose magnetic orientation varies according to an applied magnetic field, above the first contact layer, a non-magnetic layer above the ferromagnetic layer, a ferromagnetic spin injection layer above the non-magnetic layer, and a second contact layer above the spin injection layer, such that a current can flow between the second contact layer and the first contact layer along a current-perpendicular-to-plane direction, parallel to the stacking direction. The stack of layers further includes a series of structures extending along a direction parallel to the bearing surface and perpendicular to the stacking direction. | 12-11-2014 |
20150062740 | TAPE STORAGE SYSTEM - A tape storage medium includes a tape head for reading/writing data from/to a tape storage medium. At least one servo band along a longitudinal extension of the tape storage medium determines positional information. The servo band includes a set of servo tracks having a width extending along the longitudinal extension and arranged next to each other. A total of two different servo patterns are contained in the set of servo tracks. The tape head includes two servo readers. A width of each servo reader orthogonal to the longitudinal extension of the tape storage medium is at least half the width of a servo track. The two servo readers are offset from each other orthogonal to the longitudinal extension by d*wST+n*wST with wST being the width of the servo track, with 003-05-2015 | |
20150062744 | CONTROLLING THE TRANSPORT OF A TAPE WITHIN A TAPE TRANSPORT SYSTEM - A control device for controlling tape transport within a tape transport system is disclosed. The control device includes a determination unit, which includes at least a first servo channel and a second servo channel for determining a first lateral position of a tape relative to the head, and for determining a difference between the first and second lateral positions. A computing unit computes a number of unsupported wraps of the tape as a function of the lateral position difference, wherein the number of unsupported wraps corresponds to the number of layers of the tape around the take-up reel having air layers in-between, and computes a spring constant of the tape as a function of the number of unsupported wraps, a radius of the take-up reel and a nominal tape path length. A calibration unit calibrates at least one unit of the tape transport system dependent on the spring constant. | 03-05-2015 |