| Entries |
| Document | Title | Date |
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| 20080253011 | Signal Processing Device and Signal Processing Method - There is provided a signal processing apparatus and a signal processing method, which can simultaneously perform reduction in jitter components and reduction in error rate. | 10-16-2008 |
| 20080278837 | FREQUENCY, PHASE, AND GAIN ESTIMATION TECHNIQUE FOR USE IN A READ CHANNEL RECEIVER OF A HARD DISK DRIVE - One or more methods and systems are presented for performing gain and timing acquisition of data read from one or more data sectors of a hard disk drive. The gain and timing information may be used to synchronize a read channel receiver of the hard disk drive to the data read from the data sector(s). In a representative embodiment, the one or more methods comprises determining one or more frequency and phase offsets using one or more preambles of one or more data sectors residing in a hard disk drive. In a representative embodiment, the gain of the one or more preambles may be determined. In another representative embodiment, the one or more systems used to determine one or more phase and frequency offsets, and amplitudes, comprise hardware and/or software capable of utilizing a sequence of consecutive samples provided by one or more preambles of one or more data sectors. | 11-13-2008 |
| 20090002862 | FEED-FORWARD DC RESTORATION IN A PERPENDICULAR MAGNETIC READ CHANNEL - A method of feed-forward DC restoration in a perpendicular magnetic read channel is disclosed. The method generally includes the steps of (A) generating a feed-forward signal by performing a first detection on an input signal, wherein a DC component of the input signal was previously filtered out in the perpendicular magnetic read channel, (B) generating a restored signal by summing the input signal and the feed-forward signal, the summing restoring the DC component previously filtered out and (C) generating an output signal by performing a second detection on the restored signal, wherein the first detection is independent of the second detection. | 01-01-2009 |
| 20090052074 | Perpendicular magnetic recording media and magnetic storage apparatus using the same - Embodiments of the present invention provide a perpendicular magnetic recording media having excellent resolution, signal to noise ratio (S/N), and a small adjacent track erasure. According to one embodiment, underlayers for controlling the orientation and segregation of a magnetic layer, a magnetic layer including an oxide and an alloy of magnetic materials mainly composed of Co, Cr, and Pt, and a ferromagnetic-metal layer which does not contain oxygen, are formed over a substrate. The magnetic layer has at least two layers including ferromagnetic grains and oxides, a first magnetic layer, which is the part of the magnetic layer closer to the substrate, has grain boundaries mainly composed of Cr oxide and at least one oxide selected from Si, Ti, Nb, and Ta, and grain boundaries of a second magnetic layer at the ferromagnetic-metal layer side includes at least one oxide selected from Si, Ti, Nb, and Ta in which Cr oxide is less than the first magnetic layer. | 02-26-2009 |
| 20090153998 | STORAGE MEDIUM REPRODUCING APPARATUS AND STORAGE MEDIUM REPRODUCING METHOD - A storage medium reproducing apparatus includes a storage medium that records data; a reproducing head that reads the data recorded in the storage medium; a positioning controlling unit that performs positioning control of the reproducing head with respect to tracks based on servo signals from the servo area included in the storage medium; and a reproducing processing unit that reproduces the data recorded in data area in the storage medium by reading recording dots of the data area using the reproducing head the position of which is decided on the tracks, wherein the reproducing head has a head width capable of simultaneously reading a plurality of servo dots. | 06-18-2009 |
| 20090190246 | METHOD OF READING DATA STORED IN A DATA STORAGE DEVICE AND DATA STORAGE DEVICE THAT PERFORMS A DATA READ RETRY OPERATION - A disk drive includes a disk having a track that includes a data sector divided by a servo sector so that a first data sector portion is on a first side of the servo sector, and a second data sector portion is on a second side of the servo sector. The disk drive reads data by: positioning the head at a first offset position with respect to the track and reading data from the data sector. When a read error occurs between the first and second data sector portions, the disk drive: stores the data from the first data sector portion in memory, moves the head to a second offset position with respect to the track, reads data from the second data sector portion with the head at the second offset position, and stores the data read from the second data sector portion in the memory. | 07-30-2009 |
| 20090231745 | PROGRAMMABLE SOFT-OUTPUT VITERBI ALGORITHM SYSTEM AND METHOD - In a particular embodiment, a channel detector is disclosed that includes a programmable look-up table (LUT) to relate user bits to channel bits. The programmable LUT is adapted to be implemented on a state trellis of arbitrary radix. The channel detector further includes a sectional precoder coupled to a channel and having access to the programmable LUT. The sectional precoder is adapted to map channel bits to user bits and vice versa using a programmable LUT. | 09-17-2009 |
| 20090237825 | STORAGE DEVICE AND CONTROL METHOD THEREOF - A storage device includes an access counter that counts the number of track changes or the number of accessed sectors in accessing the recording medium, an access judgment unit that judges whether the recording medium is accessed successively by a host,
| 09-24-2009 |
| 20090262447 | STORAGE DEVICE - A storage device includes: a storage unit for writing data into a rotating storage medium via a writing head; a nonvolatile memory; a temporary storage memory for storing a plurality of writing commands temporarily; and a controller for executing the plurality of writing commands so as to selectively write data into the storage unit or the nonvolatile memory, rearranging the writing commands stored in the temporary storage memory in accordance with efficiency for executing the writing commands to write data into the storage unit, sequentially executing the rearranged writing commands in descending order, and executing in parallel at least one of the writing commands that has not been executed to write data into the nonvolatile memory until all the data to be written in accordance with the writing commands are stored in either the storage unit or the nonvolatile memory. | 10-22-2009 |
| 20090284859 | DATA STORAGE DEVICE HAVING DIFFERENT CONTROL INFORMATION IN DIFFERENT AREAS AND METHOD OF PROVIDING AND EMPLOYING THE SAME - A data storage device, such as a disk drive unit, includes at least one disk for storing data therein. The disk is divided into a plurality of tracks. The disk has at least a first set of tracks that each have stored therein at least one repeatable runout correction code for at least one area of the track, and a second set of tracks that each do not have stored therein any repeatable runout correction codes. | 11-19-2009 |
| 20090323213 | SERVO SIGNAL RECORDING METHOD AND MAGNETIC DISK APPARATUS - An MCU included in a magnetic disk apparatus determines, as a defective track, a track in which a servo signal abnormality is generated in a servo sector of the magnetic disk, and performs control to rewrite the servo signal to the defective track based on servo signal information for one round of a normal track in which the servo signal is normally written. | 12-31-2009 |
| 20100053793 | Systems and Methods for Adaptive Write Pre-Compensation - Various embodiments of the present invention provide systems and methods for write pre-compensation. For example, various embodiments of the present invention provide methods for modifying magnetic information transfer. The methods include retrieving magnetically represented data from a storage medium, and converting the magnetically represented data to a series of data samples. A preceding pattern and a transition status is identified in the series of data samples, and an equalized channel response is computed based on an estimated NLTS value. An error value is computed that corresponds to a difference between the estimated NLTS value and an actual NLTS value, and a pre-compensation value is computed based at least in part on the error value. | 03-04-2010 |
| 20100097714 | GENERATING PES USING READBACK SIGNAL DISTORTION - A data storage system includes a storage medium having a plurality of data sectors and a head that communicates with the data storage medium. The head produces a readback signal when reading information from the data storage medium. A computation unit extracts a distortion component of the readback signal and generates a position error signal from the distortion component. | 04-22-2010 |
| 20100142075 | Data Storage Drive with Reduced Power Consumption - A data storage drive comprises a storage disk, a read/write head, and signal processing circuitry in signal communication with the read/write head. The read/write head is operative to read data from and write data to the storage disk at a plurality of data transfer rates. Moreover, the signal processing circuitry is powered by a variable power source. The variable power source vanes supply voltage to the signal processing circuitry as a function of a current one of the data transfer rates of the read/wine head. Power consumption is reduced in this manner. | 06-10-2010 |
| 20100157457 | Electrical Interconnect system with integrated transmission- line compensation components - Impedance compensation features are used along the transmission-line path between a transmitter/driver/source and the receiver/transducer to compensate for the impedance discontinuities or mismatches (for example, those caused by physical interconnection features) and/or to improve the frequency response of the signal transfer along the transmission line. The impedance compensation features are non-uniformities with impedance characteristics selected to compensate for the target impedance discontinuities. The compensation features can be non-uniformities (geometric structures designed to have specific impedance characteristics) in the electrically conductive traces that are integrated in the interconnect transmission line between the transmitter/driver/source and the receiver/transducer. The effective impedance level of the transmission line can be lowered or raised using the compensation features. | 06-24-2010 |
| 20100157458 | Systems and Methods for Dibit Correction - Various embodiments of the present invention provide systems and methods for providing a corrected dibit signal. As an example, various embodiments of the present invention provide dibit correction circuits. Such dibit correction circuits include a dibit sample buffer, a maximum sample detector circuit, a side sample detector circuit, and a dibit correction circuit. The dibit sample buffer includes a plurality of samples of an uncorrected dibit signal. The maximum sample detector circuit identifies a maximum sample of the plurality of samples of the uncorrected dibit signal, and the side sample detector circuit identifies a first side sample prior to the maximum sample on the uncorrected dibit signal and a second side sample following the maximum sample on the uncorrected dibit signal. The dibit correction circuit applies a correction factor calculated based at least in part on the maximum sample, the first side sample and the second side sample to at least a subset of the plurality of samples of the uncorrected dibit signals to yield a plurality of corrected dibit signals. | 06-24-2010 |
| 20100172046 | Systems and Methods for Equalizer Optimization in a Storage Access Retry - Various embodiments of the present invention provide data processing circuits that include a multiplexer, a memory buffer, a data processing circuit, and a channel setting modification circuit. A first input of the multiplexer receives an input data set and a second input of the multiplexer receives a buffered data set. The multiplexer provides either the input data set or the buffered data set as a multiplexer output based upon a select signal. The memory buffer receives the multiplexer output and provides the buffered data set. Operation of the data processing circuit is at least in part governed by channel settings. The data processing circuit receives the multiplexer output and performs a data detection process. The select signal is asserted to select the buffered data set when the data detection process fails, and is asserted to select the input data set when the data detection process succeeds. The channel setting modification circuit is operable to modify the channel settings when the data detection process fails. | 07-08-2010 |
| 20100172047 | System, method, and computer program product for characterizing media associated with data storage channels - A system in one embodiment includes multiple analog inputs for receiving readback signals, an analog to digital converter coupled to each of the analog inputs for converting the readback signals to digital signals, a buffer coupled to outputs of the analog to digital converters for at least temporarily storing the digital signals, and a digital processing section also coupled to outputs of the analog to digital converters for processing the digital signals for reconstructing data therefrom. A method in one embodiment includes receiving multiple channels of analog readback signals from a magnetic head, converting the analog signals in each channel to digital signals, buffering the digital signals, and outputting the buffered digital signals. A method in another embodiment includes receiving a readback waveform from a magnetic storage device, reducing a frequency offset of the readback waveform, and generating a synchronized, oversampled waveform from the readback waveform. | 07-08-2010 |
| 20100177420 | REWRITING CODEWORD OBJECTS TO MAGNETIC DATA TAPE UPON DETECTION OF AN ERROR - During a read-after-write operation on magnetic tape, a first SCO is formed which includes two encoded processed user data units and is one of T SCOs in a first SCO set. The user data units are each one of T user data units in first and second user data unit sets, respectively, within the first SCO set. The first SCO set is written to the magnetic tape and is immediately read. When an error is detected in one of the user data units, a second SCO is formed to include the first user data unit and, only if an error is not detected in a user data unit in the other user data unit set, to not include the other user data unit, the second SCO being one of T SCOs in a second SCO set. Then, the second SCO set is rewritten to a later position on the tape later. | 07-15-2010 |
| 20100214682 | DISK DRIVE RETURNING DUMMY DATA TO A HOST WHEN READING AN UNWRITTEN DATA SECTOR - A disk drive is disclosed comprising a disk and a head actuated over the disk. The disk comprises a plurality of tracks, wherein each track comprises a plurality of data sectors. A read command is received from a host to read data from a target data sector. When it is determined that the target data sector has not been written by the host, dummy data is returned to the host. | 08-26-2010 |
| 20100232046 | Methods and Systems for Estimating Time Corresponding to Peak Signal Amplitude - Various systems and methods for peak signal detection. As one example, a method for peak signal detection that includes receiving a signal is disclosed. The received signal includes a signal region where the signal is increasing in amplitude, another signal region where the signal is decreasing in amplitude, and a transitional signal region coupling the first two signal regions. In some cases, the transitional region is of zero duration and the signal transitions directly from the increasing region to the decreasing region. The method further include calculating a distance between the signal region of increasing amplitude and the signal region of decreasing amplitude, and determining a peak of the received signal that is one half the distance from the signal region of increasing amplitude. | 09-16-2010 |
| 20100254037 | INFORMATION PROCESSING SYSTEM AND METHOD FOR ACCESSING INFORMATION PROCESSING DEVICE - According to one embodiment, an information processing system includes a plurality of information processing devices connected to one another and capable of transmitting/receiving data to/from one another. One information processing device includes a determiner configured to determine whether an address level included in a transmission signal transmitted from another information processing device is for specifying the one information processing device based on information on the address level, and a data receiver configured to receive real data included in the received transmission signal when the determiner determines that the address level is for specifying the one information processing device. The another information processing device includes an address-data converter configured to convert address data for specifying the one information processing device to a corresponding address level, and a transmitter configured to transmit the transmission signal including information on the address level obtained by the address-data converter and the real data for the one information processing device. | 10-07-2010 |
| 20100284103 | MAGNETORESISTIVE EFFECT DEVICE, MAGNETIC HEAD, AND INFORMATION STORAGE APPARATUS - A magnetoresistive effect device includes an underlayer, an antiferromagnetic layer, a first ferromagnetic layer, a nonmagnetic layer, and a second ferromagnetic layer which are multilayered in this order on a substrate. The underlayer is formed of a metal nitride, and the antiferromagnetic layer is formed of an antiferromagnetic material including Ir and Mn. | 11-11-2010 |
| 20100290146 | Method for Interfacing Non-Volatile Medium Control System Components - In a method for causing data to be written to a non-volatile medium, first data to be encoded and written in a sector of the non-volatile medium as a codeword is transmitted to a write or read/write channel device, and a write gate signal corresponding to the sector is asserted. Asserting the write gate signal indicates to the write or read/write channel device when to write the codeword to the sector. While asserting the write gate signal to cause the codeword to be written, second data to be encoded and written to the non-volatile medium is transmitted to the write or read/write channel device. | 11-18-2010 |
| 20100302668 | Parallel Information Processing on a Hard Disk Drive - A method of how to perform parallel binary information processing on a hard disk drive with magnetic media is invented. Two or more recording heads synchronously and independently write the binary information in the form of “positive” or “negative” “pulses”. All previous information is erased. Then, the sensors synchronously read the profiles of previously written information. As the result of adding, we obtain the superimposed signals that contain information on logic operations. Such operations can be made in parallel for several independent channels of information and with different groups of binary numbers. | 12-02-2010 |
| 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 |
| 20110007414 | MAGNETIC RECORDING MEDIUM, METHOD OF MANUFACTURING MAGNETIC RECORDING MEDIUM, AND MAGNETIC RECORDING/REPRODUCING APPARATUS - Disclosed is a method of manufacturing a magnetic recording medium capable of effectively and reliably removing foreign materials on the surface of a magnetic recording medium, preventing a mask layer from remaining on the surface of the magnetic recording medium, and forming the pattern of a magnetic layer with high productivity. The method of manufacturing a magnetic recording medium includes: a step of forming a magnetic layer on a non-magnetic substrate; a step of forming a mask layer on the magnetic layer; a step of patterning the mask layer to form a mask pattern; a step of forming a magnetic recording pattern on the magnetic layer using the mask pattern; a step of burnishing the surface of the mask pattern with an abrasive; and a step of removing the mask pattern. | 01-13-2011 |
| 20110019300 | PULSE WRITING FOR BIT PATTERNED AND CONTINUOUS MEDIA RECORDING - Data storage systems are provided. Data storage systems illustratively include a writing element and a recording medium. In some embodiments, the writing element generates first and second magnetization fields that respectively record first and second magnetization patterns to the recording medium. In some embodiments, the writing element is de-saturated between recording the first and second magnetization patterns. | 01-27-2011 |
| 20110019301 | Systems and Methods for High Order Assymetry Correction - Various embodiments of the present invention provide systems and methods for signal offset cancellation. For example, a method for error cancellation is disclosed. The method includes: receiving an input signal that includes a second order error component; applying a transfer function to the processed input to reduce the second order error component; and providing an output signal that is the result of applying the transfer function to the input signal. | 01-27-2011 |
| 20110019302 | METHOD OF REFRESHING DATA STORED ON A DISK - According to one embodiment, a disk comprises an area which comprises a plurality of data tracks and is partitioned into a first segment and a plurality of second segments. A controller detects that a segment to be refreshed next is one of the plurality of second segments. The controller saves data stored in the one of the plurality of second segments into the first segment when a segment to be refreshed next is the one of the plurality of second segments. | 01-27-2011 |
| 20110058271 | SYSTEMS AND METHODS FOR REDUCING CROSSTALK BETWEEN ADJACENT WRITERS - In one general embodiment, a recording system controller includes a controller controlling a timing of flux switching of adjacent pairs of writers such that the writers in a given pair do not switch substantially concurrently, and reducing a current of one of the writers in the pair while the adjacent writer is writing a transition. In another general embodiment, a recording system controller includes a controller controlling a timing of pulse writing of adjacent pairs of writers such that the writers in a given pair do not pulse substantially concurrently. In yet another general embodiment, a method includes controlling a timing of pulse writing or flux switching of adjacent pairs of writers such that the writers in a given pair do not pulse or switch substantially concurrently. | 03-10-2011 |
| 20110063747 | Systems and Methods for Timing and Gain Acquisition - Various embodiments of the present invention provide systems and methods for acquiring timing and/or gain information. For example, various embodiments of the present invention provide data processing circuits that include a sample splitting circuit, a first averaging circuit, a second averaging circuit and a parameter calculation circuit. The sample splitting circuit receives a data input that includes a series of samples that repeat periodically over at least a first phase and a second phase. The sample splitting circuit divides the series of samples into at least a first sub-stream corresponding to the first phase and a second sub-stream corresponding to the second phase. The first averaging circuit averages values from the first sub-stream to yield a first average, and the second averaging circuit averages values from the second sub-stream to yield a second average. The parameter calculation circuit calculates a parameter value based at least in part on the first average and the second average. | 03-17-2011 |
| 20110063748 | HARD DISK DRIVE WITH REDUCED POWER CONSUMPTION, RELATED DATA PROCESSING APPARATUS, AND I/O METHOD - A hard disk drive is disclosed and related methods of reading/writing data are disclosed. The hard disk drive includes a disk serving as a main data storage medium, and first and second buffers storing data to be stored on the disk, as well as a controller defining a data I/O path in relation to a detected operating state of the hard disk drive. | 03-17-2011 |
| 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 |
| 20110102928 | LOW FREQUENCY BOOSTER FOR RV/SHOCK/FRICTON DISTURBANCE REJECTION - A system for removing low frequency disturbance signals from a control system output. The system includes a controller, a mixer, a feedback loop, and a low pass filter. The controller generates a control signal. The mixer is connected to the controller and receives the control signal from the controller. The feedback loop connects an output of said mixer to an input of the mixer. A low pass filter in the feedback loop allows low frequency disturbance signals in the control signal output from the mixer to pass through the feedback loop and to be added to the control signal by said mixer for handling by the controller. | 05-05-2011 |
| 20110181976 | POWER-SAVING METHOD AND OPERATING SYSTEM FOR THE SAME - A power-saving method adapted in a hard disk in a computer system having a CPU and a memory module is provided. The power-saving method comprises the following steps. A data-to-be-written is transferred from the memory module through the CPU to the hard disk filter. A determining module is provided to determine whether a data access frequency of the computer system exceeds a threshold value. When the data access frequency exceeds the threshold value, the determining module further determines whether a request-queuing time exceeds an idle-mode activation time. When the request-queuing time exceeds the idle-mode activation time interval, the data-to-be-written is stored in a temporary storage location by the hard disk filter. When a condition of the computer system is satisfied, the data-to-be-written is written to the hard disk to extend the duration of an idle-mode of the hard disk. A power-saving operating system is disclosed herein as well. | 07-28-2011 |
| 20110205655 | MAGNETIC RECORDING HEAD, MAGNETIC HEAD ASSEMBLY, AND MAGNETIC RECORDING APPARATUS - According to one embodiment, a magnetic recording head includes a main magnetic pole, a shield, and a stacked structure body. The shield is provided to oppose the main magnetic pole. The stacked structure body is provided between the main magnetic pole and the shield. The stacked structure body includes a first magnetic layer, a second magnetic layer, and an intermediate layer. The first magnetic layer has coercivity lower than a magnetic field applied from the main magnetic pole. A size of a film surface of the second magnetic layer is larger than a size of a film surface of the first magnetic layer. The intermediate layer is provided between the first magnetic layer and the second magnetic layer and is made of a nonmagnetic material. A current is configured to pass between the first magnetic layer and the second magnetic layer. | 08-25-2011 |
| 20110216432 | MAGNETIC HEAD COMPRISING TWO MAGNETIC FIELD SENSING PART - A reading element of a magnetic head has a first magnetoresistive effect part (first MR part) and a second magnetoresistive effect part (second MR part), an electrical resistance of the first MR part changing according to an external magnetic field applied to a first magnetic field sense area, an electrical resistance of the second MR part changing according to an external magnetic field applied to a second magnetic field sense area. A width of the second magnetic field sense area in a track width direction of the recording medium is larger than a width of the first magnetic field sense area in the track width direction, and a phase of change in the electrical resistance of the second MR part with respect to the external magnetic field substantially reverses to or substantially the same as a phase in the electrical resistance of the first MR part. The magnetic head produces an output signal that comprises a sum or difference of a first sense signal and a second sense signal, the first sense signal being based on the change of the electrical resistance of the first MR part, the second sense signal being normalized to a predetermined amount and being based on the change of the electrical resistance of the second MR part, and determines the magnetic information written on the recording medium from the output signal. | 09-08-2011 |
| 20110242694 | MAGNETIC HEAD AND DISK DRIVE WITH SAME - According to one embodiment, a magnetic head for perpendicular recording includes a first magnetic core includes a main pole configured to produce a recording magnetic field, and a return pole configured to reflux magnetic flux from the main pole to form a magnetic circuit in conjunction with the main pole, a first coil configured to excite magnetic flux in the magnetic circuit, side shields arranged individually on opposite sides of the main pole transversely relative to a track so as to be magnetically separated from the main pole and formed integrally with the return pole, a second magnetic core configured to form a physically closed magnetic path, a part of which comprises the return pole, and a second coil wound around the second magnetic core and configured to excite magnetic flux in the closed magnetic path. | 10-06-2011 |
| 20110249356 | DISK STORAGE APPARATUS AND METHOD FOR RECORDING DATA - According to one embodiment, a disk storage apparatus includes a data recording module and a controller. The data recording module is configured to record a first sync mark and a second sync mark in each data sector provided on a disk. The controller is configured to control the data recording module, causing the data recording module to omit recording the second sync mark in one of segments into which the data sector is split. | 10-13-2011 |
| 20120014011 | DISK FILE PREAMPLIFIER FREQUENCY-RESPONSE AND TIME DELAY COMPENSATION - An apparatus including one or more reader circuits, one or more writer circuits, and a loopback channel. The one or more reader circuits may be configured to read data from a magnetic medium. The one or more writer circuits may be configured to write data to the magnetic medium. The loopback channel is coupled between the one or more reader circuits and the one or more writer circuits. | 01-19-2012 |
| 20120019946 | Systems and Methods for Adaptive Baseline Compensation - Various embodiments of the present invention provide systems and methods for reducing low frequency loss in a magnetic storage device. For example, some embodiments provide data processing circuits that include: an input circuit, a processing circuit, a data detection circuit, and a baseline compensation circuit. The input circuit receives a first data input and provides a second data input. The input circuit excludes low frequency energy exhibited in the first data input from the second data input. The processing circuit generates a representation of the second data input, and the data detection circuit generates a representation of the first data input based at least in part on the representation of the second data input. The baseline compensation circuit calculates an accumulated difference between the representation of the first data input and the representation of the second data input across a number of bit periods, and calculates a compensation factor based at least in part on the accumulated difference. | 01-26-2012 |
| 20120033319 | READ PATH COMPENSATION FOR SNR AND SIGNAL TRANSFER - A method and apparatus is provided for extending a read bandwidth and increasing a high-frequency signal-to-noise ratio (SNR) of a front-end of a read path of a hard disk drive (HDD) by introducing a high impedance section at the front-end of the read path. The high impedance section may mitigate capacitive effects found at the front-end of the read path, thereby improving signal transfer by extending the read bandwidth. | 02-09-2012 |
| 20120033320 | Systems and Methods for Dynamic Scaling in a Read Data Processing System - Various embodiments of the present invention provide systems and methods for data processing. For example, a data processing system is disclosed that includes a decoder circuit providing a decoded output, and a dynamic scalar calculation circuit that determines a first dynamic scaling value and a second dynamic scaling value based at least in part on the decoded output. A first multiplier circuit multiplies the decoded output by the first dynamic scaling value and provides a first scaled output. A detector circuit receives the first scaled output and provides a detected output. A second multiplier circuit multiplies the detected output by the second dynamic scaling value and provides a second scaled output. | 02-09-2012 |
| 20120087031 | ADAPTIVE DISTURBANCE COMPENSATION WITH MULTI-RATE SYNCHRONIZED SAMPLING - 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. | 04-12-2012 |
| 20120087032 | PULSE POWER DURING A SHUT DOWN IN A HARD DISK DRIVE - A HDD including write components configured to operate within an operating voltage range, charging circuitry comprising a charging capacitor. The charging capacitor includes a higher voltage when charged than the operating voltage range. The HDD also includes pulse circuitry configured to pulse power from the charging circuitry to the write components within the operating voltage range during a controlled shut down of the write components such that remaining data-sector bits are written during the controlled shut down. | 04-12-2012 |
| 20120087033 | Systems and Methods for Identifying Potential Media Failure - Various embodiments of the present invention provide systems and methods for medium utilization control. As an example, a method for identifying potentially damaged media regions is discussed that includes receiving a data set; performing a data detection process on the data set to yield a detected output and a status value corresponding to the data set; performing a data decoding process on the detected output to yield a decoded output; and identifying a region of a storage medium from which the data set was derived as failing based at least in part on the status value. | 04-12-2012 |
| 20120099216 | SYSTEM, METHOD AND APPARATUS FOR STORAGE ARCHITECTURE FOR BIT PATTERNED MEDIA USING BOTH ERASE BAND AND SHINGLED MAGNETIC RECORDING - Storage architecture for bit patterned media uses both erase band and shingled magnetic recording. A hard disk drive may comprise a disk having bit patterned media with a plurality of data tracks arrayed in architecture pages having at least one of erase band mode (EBM), shingled mode (SM) and unallocated space. An actuator has a head for writing data to the data tracks of the bit patterned media. A control system monitors, reallocates and reconfigures the architecture pages from EBM, SM or unallocated space to a different one of EBM, SM or unallocated space to enhance performance of the hard disk drive. | 04-26-2012 |
| 20120194937 | MAGNETIC RECORDING APPARATUS AND RECORDING METHOD OF MAGNETIC RECORDING APPARATUS - According to one embodiment, a magnetic recording apparatus configured to record information onto a magnetic recording medium by a shingled write recording method, the magnetic recording apparatus includes: a recording head configured to cover a plurality of dot arrays and an end portion of which is situated at one dot array of a recording target; an actuator configured to move the recording head by one array after the recording to one dot array by the recording head; and a controller configured to perform recording compensation of the magnetic dot based on prestored recording data of a peripheral dot of a magnetic dot when input user data is recorded to the magnetic dot. | 08-02-2012 |
| 20120212850 | SYSTEM AND METHOD FOR RETENTION MANAGEMENT AND REORDERING THEDATA BASED ON RETENTION TIMES ON TAPE - Retention management for data stored in data blocks on a tape is provided. A block mapping table has entries each of which include an expiration date for data blocks stored on the tape. The entries of the block mapping table may be sorted in accordance with at least one sorting criterion. Data blocks on the tape are rearranged according to the block mapping table. The block mapping table is then stored, either on the tape or in a memory associated with the tape. | 08-23-2012 |
| 20120236430 | Systems and Methods for Auto Scaling in a Data Processing System - Various embodiments of the present invention provide systems and methods for data processing. As an example, a data processing circuit having a data detection circuit is disclosed that includes: a scaling circuit, a soft output calculation circuit, and a factor calculation circuit. The scaling circuit is operable to scale a branch metric value by a scaling factor to yield a scaled output. The soft output calculation circuit is operable to calculate a soft output based at least in part on the scaled output. The factor calculation circuit operable to modify the scaling factor based at least in part on the soft output. | 09-20-2012 |
| 20120300329 | MAGNETIC DISK DRIVE USING A NON-VOLATILE STORAGE DEVICE AS CACHE FOR MODIFIED TRACKS - Provided are a computer program product, system, and method for a magnetic disk drive. The disk drive has at least one disk platter having at least one recordable disk surface having an areal density of at least 200 gigabits per square inch. Either a diameter of the at least one disk platter is greater than 3.5 inches or the at least one disk platter rotates at less than 5400 RPMs. A read/write head reads and writes tracks of data with respect to the at least one disk surface. Modified tracks from write requests to write to the at least one disk surface on the at least one disk platter are cached in a non-volatile storage device for caching modified tracks. Modified tracks are cached in the non-volatile storage device to later destage to the at least one disk surface. | 11-29-2012 |
| 20130003211 | FAST DATA RECOVERY FROM HDD FAILURE - A storage system comprises a first storage device having a first plurality of hard disk drives and a first controller. The first controller stores data in the first plurality of hard disk drives by stripes. Each stripe includes M data and N parity data allocated to M+N hard disk drives of the first plurality of hard disk drives. A first hard disk drive includes data or parity data of both a first stripe of the stripes and a second stripe of the stripes, while a second hard disk drive includes data or parity data of only one of the first stripe or the second stripe. During data recovery involving failure of one of the first plurality of hard disk drives, the data in the failed hard disk drive is recovered for each stripe by calculation using data and parity data in other hard disk drives for each stripe. | 01-03-2013 |
| 20130077187 | Adaptive Correction of Symmetrical and Asymmetrical Saturation in Magnetic Recording Devices - In one embodiment, a read channel comprises: a preprocessor for receiving a first signal and producing a second signal from the first signal using current values of a positive coefficient, a zero coefficient, and a negative coefficient; an interpolator for producing a third signal based on the second signal; and a slicer for producing a fourth signal from the third signal by estimating a level for the third signal. The fourth signal is at one of three levels consisting of a positive level, a zero level, and a negative level. For every n first signals received by the preprocessor, the current value of one of the positive coefficient, the zero coefficient, and the negative coefficient is adjusted depending on which of the three levels the fourth signal is at. | 03-28-2013 |
| 20130083416 | SHINGLED RECORDING SYSTEMS USING MULTIPLE PASS WRITE, SINGLE PASS READ ARCHITECTURE - In one embodiment, a magnetic data storage system includes a bit patterned magnetic medium, wherein centers of bits in adjacent data tracks do not lie on a common line in a cross-track direction, a magnetic head having a writer element having a width greater than a width of a data track in a track width direction adapted for writing data successively to at least two adjacent data tracks of the magnetic medium, and a reader element having a width larger than the width of a data track in the track width direction adapted for reading data concurrently from the at least two adjacent data tracks of the magnetic medium in a single pass, a drive mechanism for passing the magnetic medium over the magnetic head, and a controller electrically coupled to the magnetic head for controlling operation of the magnetic head. | 04-04-2013 |
| 20130100550 | IMPLEMENTING MAGNETIC DEFECT CLASSIFICATION USING PHASE MODULATION - A method, apparatus, and system are provided for implementing magnetic defect classification using phase modulation for hard disk drives. A magnetic media readback signal of a hard disk drive is processed to identify predefined phase modulation (PM) characteristics to implement magnetic defect classification of magnetic media bump and pit defects. | 04-25-2013 |
| 20130100551 | METHOD AND APPARATUS FOR REFLECTION CANCELLATION - A method for calibrating a reflection compensator is provided. A delay is initially set to a predetermined minimum, and an input pulse is transmitted across a transmission line. A compensation current is then applied after the delay. The reflection from the transmission line is digitized to generate a measurement, and a determination is made as to whether the compensation current substantially compensates for the reflection. If the compensation current does not substantially compensate for the reflection, then the delay is adjusted, and the process is repeated until the compensation current substantially compensates for the reflection. | 04-25-2013 |
| 20130107391 | DISK-BASED STORAGE DEVICE HAVING READ CHANNEL MEMORY THAT IS SELECTIVELY ACCESSIBLE TO DISK CONTROLLER | 05-02-2013 |
| 20130107392 | DIGITAL INPUT DETECTOR AND ASSOCIATED ADAPTIVE POWER SUPPLY | 05-02-2013 |
| 20130120867 | Methods and Apparatus for Map Detection with Reduced Complexity - Methods and apparatus are provided for high-speed, low-power, high-performance channel detection. A soft-output detector is provided for processing a received signal, comprising: a forward detector for calculating forward state metrics; a backward detector for calculating backward state metrics; and a current branch detector for calculating a current branch metric, wherein at least two of the forward detector, the backward detector and the current branch detector employ trellis structures with a different number of states. A method is provided for processing a received signal using a soft-output detector, comprising: calculating forward state metrics using a forward detector; calculating backward state metrics using a backward detector; and calculating a current branch metric using a current branch detector, wherein at least two of the forward detector, the backward detector and the current branch detector employ trellis structures with a different number of states. | 05-16-2013 |
| 20130170061 | SYSTEM, METHOD AND APPARATUS FOR SHINGLED MAGNETIC RECORDING IN DISK DRIVES - A method of targeted corruption of user data in a shingled magnetic recording disk includes identifying user data on a Track_N targeted for corruption; identifying a readback centerline of the Track_N; identifying a readback centerline of an adjacent track to Track_N; acquiring user data of the adjacent track; and rewriting the user data of the adjacent track with an offset write centerline to overwrite magnetic material at the readback centerlines of both Track_N and the adjacent track. | 07-04-2013 |
| 20130176639 | PROXIMITY SENSING SYSTEM - A data storage system for detecting a location of a head relative to a magnetic media is described. This system comprises arms, a preamplifier circuit coupled to the arms for controlling the arms, a proximity sensing system positioned within the preamplifier circuit, the proximity sensing system comprising: an input stage for transmitting an input sense signal; a programmable gain stage coupled to receive the input sense signal and operative for transmitting a gain signal in response to receiving the input sense signal; a multiplexer coupled to receive the gain signal and at least one control signal, the multiplexer operative for transmitting a multiplexed signal; a detector coupled to receive the multiplexed signal and a second control signal, the detector operative for transmitting an output signal; wherein an amplitude associated with the output signal enables detecting the location of the head. | 07-11-2013 |
| 20130182347 | SIGNAL PROCESSING APPARATUS, SIGNAL PROCESSING METHOD, AND MAGNETIC DISK APPARATUS - According to at least one embodiment, a signal processor apparatus includes a Viterbi decoder, a processor, and an adjustment module. The Viterbi decoder calculates a branch metric based on an input signal. The processor outputs a processing result correlated with a processing result of the Viterbi decoder. A latency of the processor for the input signal is lower than a latency of the Viterbi decoder. The adjustment module adjusts a first parameter for calculating the branch metric based on the processing result of the processor. | 07-18-2013 |
| 20130194691 | MAGNETIC DISK DRIVE AND METHOD FOR CONTROLLING THE SAME - According to one embodiment, there is provided a magnetic disk device including an acceleration feedforward module, an eccentricity correction module, and a control module. The acceleration feedforward module includes a first amplification module, a second amplification module, and an addition module. The first amplification module amplify a first rotation correlation value according to a rotation component by a first gain. The second amplification module amplifies a second rotation correlation value according to a rotation synchronization component of the rotation component, by a second gain acquired by subtracting the first gain from 1. The addition module adds the first rotation correlation value amplified by the first amplification module and the second rotation correlation value amplified by the second amplification module to obtain the first correction amount. | 08-01-2013 |
| 20130194692 | MAGNETIC DISK DRIVE AND METHOD FOR SERVO PREAMBLE LENGTH ADJUSTMENT APPLIED TO THE SAME - According to one embodiment, a magnetic disk drive includes a disk and a controller. The disk includes a plurality of zones each having a plurality of tracks. The disk is formatted such that a plurality of servo frames are discretely recorded in each of the plurality of tracks. The plurality of servo frames include servo preamble data of a second length which corresponds to the zone having the track and which is less than or equal to a first length serving as a reference. The controller allows a head to read the servo frames from the disk via a read amplifier. | 08-01-2013 |
| 20130235484 | Multi-Path Data Processing System - Various embodiments of the present invention provide apparatuses and methods for processing data in a multi-path data processing circuit. For example, an apparatus is disclosed that includes a first filter operable to process a first digital data stream to yield a first filtered digital data stream, a second filter operable to process a second digital data stream to yield a second filtered digital data stream, wherein the first and second digital data stream are representative of a same data set and wherein the first and second digital data stream have a different phase, a combining circuit operable to combine the first filtered digital data stream and the second filtered digital data stream to yield a combined data stream, and a data detector operable to detect a data sequence in the combined data stream. | 09-12-2013 |
| 20130286497 | MULTI-RATE OVERSAMPLING OF ANALOG SIGNALS IN STORAGE DEVICES - Multi-rate oversampling of analog signals in storage devices is described. A method of processing an analog signal derived from a storage medium in a storage device includes: filtering the analog signal with an anti-alias filter having a fixed cut-off frequency related to a target sampling rate; sampling the analog signal using an over-sampling rate of a plurality of over-sampling rates provided by a variable-rate analog-to-digital converter (ADC) to produce an over-sampled digital signal; and filtering the over-sampled digital signal using a decimation filter of a plurality of decimation filters provided by a digital signal processor (DSP) to produce a digital signal having the target sampling rate. | 10-31-2013 |
| 20130308221 | Systems and Methods for Symbol Re-Grouping Decoding Processing - The present invention is related to systems and methods for applying a data decode algorithm to different rotations or modifications of a decoder input as part of data processing. | 11-21-2013 |
| 20130335845 | ADAPTIVE SOFT-OUTPUT DETECTOR FOR MAGNETIC TAPE READ CHANNELS - In one embodiment, a data storage system includes a tape channel for reading data from a tape to produce a signal, an adaptive noise whitening filter adapted for receiving the signal, the noise whitening filter being adapted for minimizing variance of noise affecting the signal output from the noise whitening filter, a soft DMAX detector adapted for receiving the signal from the noise whitening filter, the soft detector adapted for calculating first soft information about each bit of the signal and sending the first soft information to a soft decoder, and the soft decoder positioned subsequent to the soft detector, the soft decoder being adapted for calculating second soft information about each bit of the signal and sending the second soft information to the soft DMAX detector, wherein one or more noise whitening coefficients used in the noise whitening filter are updated using a noise whitening filter coefficient updater. | 12-19-2013 |
| 20130335846 | ADAPTIVE SOFT-OUTPUT DETECTOR FOR MAGNETIC TAPE READ CHANNELS - In accordance with one embodiment, a data storage system includes a tape channel for reading precoded data from a magnetic tape medium to produce a signal, a soft detector adapted for calculating first soft information about each bit of the signal and sending the first soft information to a soft decoder, and the soft decoder positioned subsequent to the soft detector, the soft decoder being adapted for calculating second soft information about each bit of the signal and sending the second soft information to the soft detector, wherein the precoded data includes a characteristic of being passed through at least one precoder prior to being written to the magnetic tape medium, and wherein the soft detector provides automatic compensation for the precoded data. Other systems, methods, and computer program products for reading data using an adaptive soft-output detector are described according to more embodiments. | 12-19-2013 |
| 20140002917 | MAGNETIC RECORDING MEDIUM AND MAGNETIC STORAGE APPARATUS | 01-02-2014 |
| 20140043708 | STORING RANDOM AND SEQUENTIAL DATA ON DIFFERENT TRACK WIDTHS OF A RECORDING MEDIUM - Host data to be written to a recording medium is categorized as one of sequential data or random data. The sequential data is written to a first track width on the recording medium. The random data is written to a second track width on the recording medium, the second track width being larger than the first track width. | 02-13-2014 |
| 20140063633 | VARIABLE STOPWRITE THRESHOLD USING KURTOSIS - A method according to one embodiment includes measuring a current position error signal; calculating a standard deviation or a variance using the current position error signal sample; calculating a kurtosis value, using the current position error signal sample or derivative thereof; adjusting a threshold value using the kurtosis value; comparing the standard deviation or variance to the threshold value; enabling writing when the standard deviation or variance does not exceed the threshold value. | 03-06-2014 |
| 20140085743 | REAL TIME MRA ESTIMATION AND CORRECTION USING ADC SAMPLES - Methods and systems for estimating MRA for a hard disk drive are described. The methods and systems described herein provide for real time estimating and correcting magneto-resistive head asymmetry (MRA) in a hard disk drive using analog-to-digital convertor (ADC) samples or counts. Generally, ADC outputs may be obtained by injecting MRA at known values, where an estimated MRA may be derived in real time by applying an equation using particular ADC output values. Once an estimated MRA is obtained, MRA correction may be performed when the estimated MRA is larger than a threshold value, such as by adjusting a channel MRA compensation coefficient. | 03-27-2014 |
| 20140104714 | HIGH-RATE REVESE-ORDER RUN-LENGTH-LIMITED CODE - A system and method for encoding a stream of bits with a run-length limited high-rate reverse order encoding schema. According to one embodiment, an RLL encoding block includes a receiver having a precoder operable to receive a stream of N-bits having symbols of M-bits in length, a histogram operable to identify an index symbol of M-bits that does not occur within the received stream of N-bits. It is this index symbol that may be used as the key to encoding a block of symbols so as to ensure unique decodability when RLL decoding. Finally, an encoder operable to perform an exclusive-or operation on each symbol with the next symbol stored in the stream. Such an encoding system only adds one symbol of M bits in length to a block of N bits and still results in a stream of bits sufficient to support high-rate requirements and strict timing loop control. | 04-17-2014 |
| 20140139940 | METHODS FOR READING DATA FROM A STORAGE MEDIUM USING A READER AND STORAGE DEVICES - According to various embodiments, a method for reading data from a storage medium using a reader may be provided. The method may include: reading a first signal with a reader head of the reader at a first position of the storage medium; reading a second signal with a reader head of the reader at a second position of the storage medium; and determining data stored at a pre-determined position of the storage medium based on the first signal and based on the second signal. | 05-22-2014 |
| 20140177082 | OVER-SAMPLED SIGNAL EQUALIZER - An apparatus comprises read channel circuitry and signal processing circuitry associated with the read channel circuitry. The signal processing circuitry is configured to: equalize an oversampled digital data signal to determine an equalized digital data signal, filter the equalized digital data signal, determine a hard decision and reliability of the filtered digital data signal, and decode the filtered digital data signal based at least in part on the hard decision and reliability. The oversampled digital data signal comprises a first set of sampled digital data and a corresponding second set of sampled digital data, each of the samples in the first set of sampled digital data being offset from a corresponding one of the sample in the second set of sampled digital data by a phase difference. | 06-26-2014 |
| 20140185158 | FLY HEIGHT CONTROL FOR HARD DISK DRIVES - A fly height control circuit includes an input node to receive a digital control signal, an output node to output a control current to a resistive heater element to adjust a spacing between a read/write head and a surface of a storage medium, and control circuitry to process the digital control signal and generate the output control current based on the digital control signal. The control circuitry generates a first reference current based at least in part on the control current output from the output node. The control circuitry controls a slew rate of the first reference current to generate a slew rate controlled reference current. The control circuitry generates a second reference current based on a feedback voltage at the output node. The control circuitry compares the slew rate controlled reference current with the second reference current to adjust the control current output from the output node. | 07-03-2014 |
| 20140233129 | NOISE PREDICTIVE FILTER ADAPTATION FOR INTER-TRACK INTERFERENCE CANCELLATION - Systems, methods, devices, circuits for data processing, and more particularly to systems and methods for adapting noise predictive filters for inter-track interference cancellation in a data processing system. | 08-21-2014 |
| 20140233130 | Systems and Methods for Determining Noise Components in a Signal Set - Various embodiments of the present invention provide systems and methods for estimating noise components in a received signal set. For example, one embodiment of the present invention provides a noise estimation circuit that includes a data detector circuit and a noise component calculation circuit. The data detector circuit receives a series of data samples and provides a detected output, and the noise component calculation circuit provides an electronics noise power output and a media noise power output each calculated based at least in part on the detected output and the series of data samples. | 08-21-2014 |
| 20140240863 | MAX-LOG-MAP EQUIVALENCE LOG LIKELIHOOD RATIO GENERATION SOFT VITERBI ARCHITECTURE SYSTEM AND METHOD - A modified soft output Viterbi algorithm (SOVA) detector receives a sequence of soft information values and determines a best path and an alternate path for each soft information value and further determines, when the best and alternate paths lead to the same value for a given soft information value, whether there is a third path departing from the alternate path that leads to an opposite decision with respect to the best path for a given soft information value. The SOVA detector then considers this third path when updating the reliability of the best path. The modified SOVA detector achieves max-log-map equivalence effectively through the Fossorier approach and includes modified reliability metric units for the first N stages of the SOVA detector, where N is the memory depth of a given path, and includes conventional reliability metric units for the remaining stages of the detector. | 08-28-2014 |
| 20140254041 | Servo Marginalization - Servo channel noise limits are defined through Viterbi decisions based on servo gate signals. Y values are used to produce a first Viterbi decision at each servo gate. Viterbi decisions and Y values are used to produce ideal Y values. Y values and ideal Y values are used to produce an error value which is adjusted by a noise factor based on estimated channel characteristics. The noise value is combined with Y values and used to produce a second Viterbi decision at each servo gate. | 09-11-2014 |
| 20140313608 | POWER SUPPLY CIRCUIT - Each of unit blocks (UB | 10-23-2014 |
| 20140334029 | MAGNETORESISTIVE ELEMENT, MAGNETIC HEAD, AND MAGNETIC RECORDING AND REPRODUCING APPARATUS - A magnetoresistive element according to an embodiment includes: a magnetoresistance effect film including: a first and second magnetic films; and an intermediate film disposed between the first and second magnetic films, at least one of the first and second magnetic films being formed of a Heusler alloy expressed as Co | 11-13-2014 |
| 20140347760 | HEAD TRANSDUCER WITH MULTIPLE RESISTANCE TEMPERATURE SENSORS FOR HEAD-MEDIUM SPACING AND CONTACT DETECTION - A head transducer, configured to interact with a magnetic recording medium, includes a first sensor having a temperature coefficient of resistance (TCR) and configured to produce a first sensor signal, and a second sensor having a TCR and configured to produce a second sensor signal. One of the first and second sensors is situated at or near a close point of the head transducer in relation to the magnetic recording medium, and the other of the first and second sensors spaced away from the close point. Circuitry is configured to combine the first and second sensor signals and produce a combined sensor signal indicative of one or both of a change in head-medium spacing and head-medium contact. Each of the sensors may have a TCR with the same sign (positive or negative) or each sensor may have a TCR with a different sign. | 11-27-2014 |
| 20140355149 | ITERATIVE DATA STORAGE READ CHANNEL ARCHITECTURE HAVING DROPOUT MITIGATION - According to one embodiment, a magnetic medium's readback signal samples are processed iteratively to provide dropout mitigation for a read channel by feeding the decoder output decisions back to the read channel front end where they are used to drive the decision-aided digital signal processing functions and control loops. Since data decisions provided by the decoder are typically more reliable than those provided by the detector, a significant performance improvement is obtained. A more reliable operation of the digital front-end signal processing functions in turn allows improvements to the reliability of the decoded data. Usage of Error Correcting Code (ECC) schemes that are soft decodable makes the read channel technique, described according to various embodiments herein, particularly efficient. | 12-04-2014 |
| 20140355150 | HEAD TRANSDUCER WITH MULTIPLE RESISTANCE TEMPERATURE SENSORS FOR HEAD-MEDIUM SPACING AND CONTACT DETECTION - A head transducer, configured to interact with a magnetic recording medium, includes a first sensor having a temperature coefficient of resistance (TCR) and configured to produce a first sensor signal, and a second sensor having a TCR and configured to produce a second sensor signal. One of the first and second sensors is situated at or near a close point of the head transducer in relation to the magnetic recording medium, and the other of the first and second sensors spaced away from the close point. Circuitry is configured to combine the first and second sensor signals and produce a combined sensor signal indicative of one or both of a change in head-medium spacing and head-medium contact. Each of the sensors may have a TCR with the same sign (positive or negative) or each sensor may have a TCR with a different sign. | 12-04-2014 |
| 20140362461 | Systems and Methods for Floating Variance Branch Metric Calculation - The present inventions are related to systems and methods for data processing, and more particularly to systems and methods for data detection. | 12-11-2014 |
| 20150036236 | System and Method for Calculating Data Compression Ratio without Writing Data to Media - An information handling system includes a host processor and a tape drive, which in turn includes a controller and a compression buffer. The controller is in communication with the host processor, and is configured to receive a diagnostic command from the host processor, to switch the tape drive from a normal mode to a diagnostic mode in response to the diagnostic command, and to send a compression ratio for data associated with a write command to the host processor. The compression buffer is in communication with the controller, the compression buffer configured to receive the write command, to compress data associated with the write command while in the diagnostic mode, to calculate the compression ratio for the data associated with the write command, and to delete the compressed data while the tape drive is in the diagnostic mode. | 02-05-2015 |
| 20150062733 | Method for Reading File Using Plurality of Tape Media - A storage system includes a plurality of tape drives connected, to a host, and a buffer configured to temporarily hold data read from the drives. A mechanism loads a plurality of media on which a file has been written to the plurality of drives so as to mount the plurality of media in the plurality of drives and divides the file into a plurality of data portions in an order. The mechanism determines a medium that takes the shortest time to move from a current position of a read head of a corresponding drive to a beginning position of the file and one or more media from which following data portions of the beginning data portion are to be read. The mechanism executes reading of the following data portions from the next media and temporarily holding of the read following data portions in the buffer of the storage system while reading the beginning data portion of the file from the first medium to the host. | 03-05-2015 |
| 20150092288 | SIGNAL NOISE REJECTION - An implementation of a system disclosed herein provides a method of determining a frequency of baseline noise in a target or read sensor signal and rejecting a band of signals from the target or read sensor signal substantially around the frequency of the baseline noise, including devices to implement this method. | 04-02-2015 |
| 20150138662 | TAPE DRIVE BUFFER UTILIZATION - Records or filemarks read from data segments are aggregated into at least one single data segment. The records and the filemarks are padded at an end of the one single data segment, such that the padding of the end of the one single data segment is less than padding of the one of the records and filemarks in the plurality of data segments. | 05-21-2015 |
| 20150325266 | Multi-Dimensional Optimization of Read Channel - Variations of the Nelder-Mead direct search method are employed to find read channel parameter settings in a discrete field having three or more dimensions. The three or more dimensions correspond to read channel parameters, at least some of which are highly correlated. The steps of the Nelder-Mead method are executed according to a methodology to arrive at substantially optimal parameter settings for a read channel, even where a discrete function defining parameter outcomes is noisy. In some embodiments, dimensional collapse, considered inefficient in a two-dimensional field, is allowed in order to reach an optimal solution in a greater-than-two-dimensional field. | 11-12-2015 |
| 20160064016 | DETERMINING OSCILLATION CHARACTERISTIC FOR HIGH-FREQUENCY ASSISTED MAGNETIC RECORDING DEVICE - A magnetic disk device according to an embodiment includes a magnetic head including a write head with a high-frequency oscillator and a read head, a recording medium, a driving unit configured to moves the magnetic head on the recording medium, a measuring unit configured to obtain a first read signal with no current or a smaller current and a second read signal with a normal current supplied in the normal writing operation, a comparison unit configured to calculate comparative data indicating a comparison result between the first and second read signals, and a determination unit configured to determine an oscillation characteristic from the comparative data. | 03-03-2016 |
| 20160071536 | ADJUSTMENT METHOD OF PARAMETERS OF MULTISTAGE NOTCH FILTER - According to one embodiment, a method of adjusting parameters set of a multistage notch filter includes calculating a first value which is a square sum of an error between a frequency response characteristic of a reference notch filter and a frequency response characteristic of the notch filter in evaluation points of a low-frequency band, calculating a second value which is a square sum of an amount in which an open-loop gain response characteristic which is series coupling of the object and the controller is protruded from an inverse gain response characteristic of the notch filter in evaluation points of a high-frequency band, and adjusting the parameters by simultaneously minimizing the first and second values. | 03-10-2016 |
| 20160163351 | WRITE INTERFERENCE REDUCTION WHEN READING WHILE WRITING TO A HARD DISK DRIVE MEDIA - A hard disk drive device and a method and apparatus for control of the hard disk drive is provided. The hard disk drive includes disk media, a slider head, a head gimbal assembly and a control means. The disk media includes at least two layers for data storage. The slider head flies above the disk media and includes a writer and a reader, and a head gimbal assembly supports the slider head above the disk media. The control means is physically coupled to the head gimbal assembly and electrically coupled to the writer and the reader for reducing write interference from the writer when the writer is writing to the disk media while the reader is reading from the disk media, wherein write interference is reduced in one or more of a time domain and a frequency domain. | 06-09-2016 |
| 20160180867 | MICROWAVE-ASSISTED MAGNETIC RECORDING HEAD AND MAGNETIC RECORDING APPARATUS INCLUDING THE SAME | 06-23-2016 |
| 20160189734 | ALLOWING FAST DATA ZONE SWITCHES ON DATA STORAGE DEVICES - Some embodiments described herein are directed to reducing or eliminating latency caused by data zone switches in a rotating magnetic storage device. More specifically, some embodiments described herein are directed to storing parameters associated with different zones in a parameter register in response to one or more received commands. | 06-30-2016 |
