Abstract: A system includes a memory, a processor, an encoder, a head, and a decoder. The memory stores information. The processor processes information and controls operation of other components. The encoder encodes a first portion and a second portion of a servo track to form a first and second encoded values. The second code has a run length associated therewith. The first and second encoded values result in a Gray code. Each bit of the Gray code remains constant for at least a number of tracks corresponding to the run length. The head is configured to write the first and the second encoded values onto a media, and is configured to read the first and the second encoded values from the media. The decoder decodes the first encoded value and the second encoded value. The processor determines a servo track address from the decoded first value and the decoded second value.

Abstract: Systems and methods relating generally to determining flaws on a storage medium.

Abstract: A reproducing device (100) includes (i) an optical pickup (6) for irradiating, with reproduction light, an optical disk (1) which is a super-resolution medium, (ii) an RF signal processing circuit (9) for converting, into a reproduction signal, light which reflected off optical disk (1), (iii) an i-MLSE detecting section (141) for evaluating quality of the reproduction signal, and (iv) a spherical aberration correcting section (142) for correcting a spherical aberration by using a result of evaluation of the quality of the reproduction signal.

Abstract: An apparatus includes a loop filter that receives a plurality of input signals. Each of the input signals is based on a different timing error detector output signal. The apparatus also includes a plurality of read channels, a plurality of interpolation filters, and an array of transducers. Each of the interpolation filters is in communication with a corresponding one of the read channels. Each of the transducers is in communication with a corresponding one of the read channels. The loop filter processes the plurality of input signals, and outputs a different total phase signal for each received input signal. Each of the interpolation filters samples the corresponding read channel based on one of the total phase signals output by the loop filter. The loop filter processes the plurality of input signals by calculating a phase estimate of the samples, and a skew estimate of the samples, relative to written data.

Abstract: An apparatus for storing data includes a storage medium with user data regions and with servo data regions containing preamble patterns. Servo data in the servo data regions is written with a varying clock frequency across the storage medium. The apparatus also includes a head assembly disposed in relation to the storage medium and operable to read and write data on the storage medium. The apparatus also includes a preamble detection circuit adapted to search an input stream derived from the head assembly for the preamble patterns in a number of frequency bins.

Abstract: A storage controller includes a control unit and an interface. The control unit, when write data input as data to be written onto a magnetic disk includes a bit string of a first pattern, inverts one or more bits of the bit string. The write data includes a redundancy bit string used for data error correction. The interface outputs write data including bit inverted by the control unit.

Abstract: In various embodiments, a read assembly for reading a dual-layered medium may be provided. The dual-layered medium may include a servo layer and a data layer over the servo layer. The read assembly may include a data read head configured to read the data layer. The read assembly may also include a servo read head configured to read the servo layer.

Abstract: 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.

Abstract: A plasmon generator generates a surface plasmon, and generates a near-field light from the surface plasmon on a front end surface positioned on an air bearing surface opposing to a magnetic recording medium. The plasmon generator has a first surface that is adjacent to the front end surface and that faces a lower layer where the plasmon generator is deposited, and a second surface at the back side of the first surface relative to a down track direction. The first surface tilts toward a surface that is orthogonal to the down track direction, and, is parallel to across track direction, and the plasmon generator is deposited with a (111) orientation from the first surface toward the second surface.

Abstract: A data storage device is disclosed comprising a disk comprising a plurality of data sectors and a plurality of servo sectors, and a head actuated over the disk, wherein the head comprises a laser configured to heat the disk while writing data to the disk. When the head is over a first data sector not being written, a first prelase bias is applied to the laser, and when the head is over a servo sector, a second, lower prelase bias is applied to the laser. When the head is over a second data sector being written, a write bias higher than the first prelase bias is applied to the laser.

Abstract: A method comprises writing a waveform on a magnetic recording medium using a heat-assisted magnetic recording apparatus which includes a laser. The method also comprises reading back the waveform from the medium, and detecting one or more transition shifts in the readback waveform indicative of a mode hop of the laser. The method further comprises measuring a metric of the one or more transition shifts.

Abstract: Methods of forming a NFT the methods including forming a hard mask positioned over at least a portion of the rod, the hard mask including at least one layer; patterning a resist mask over the hard mask, the resist mask having an edge positioned over at least a portion of the rod; etching a portion of the hard mask to expose a back edge of the rod and to form a back edge of the hard mask, wherein the back edge of the rod is equivalent to the back edge of the peg; and wherein a forward portion of the rod which is the portion of the rod forward of the back edge is covered by the hard mask; forming a disc mask including a void configured to form a disc of a NFT, the disc mask being formed over at least a portion of the hard mask so that the exposed back edge of the rod is within the void configured to form the disc; etching an area exposed in the void of the disc mask to remove both a rear portion of the rod and the surrounding dielectric up to the back edge of the hard mask edge; depositing a disc material in th

Abstract: A read/write head includes two or more first transducers of a first type, the first type selected from a magnetic read transducer and a magnetic write transducer. The read/write head includes one or more switching elements coupled to the two or more first transducers. The switching elements are configured to, in response to a control signal, couple a selected one of the two or more first transducers to a preamplifier circuit and decouple others of the two or more first transducers from the preamplifier circuit.

Abstract: A recording head includes a layer of plasmonic metal deposited on a surface of the recording head. One or more non-self-supporting layers of crystalline material are attached to the plasmonic metal, the one or more layers of crystalline materials configured to form an active region of a laser. A waveguide is configured to receive plasmons from the laser and direct the plasmons to a recording medium.

Abstract: A procedure for detecting the presence of contamination at a head-disk interface in a heat- assisted magnetic recording (HAMR) hard disk drive involves flying a head slider over a magnetic-recording disk at a particular fly height, applying an oscillating signal to a heat source associated with a HAMR near-field transducer (NFT) that is located in the slider to dither the spacing between the NFT and the disk, and determining, based on change to a contact detection signal, that contamination has accumulated on the slider, generally, or on the NFT, specifically. Burnishing the contamination from the slider may then be performed, by bringing the slider into contact with the disk.

Abstract: A heat-assisted magnetic recording (HAMR) disk has multiple independent data layers, each data layer being a continuous non-patterned layer of magnetizable material. Each data layer can store data independent and not related to the data stored in the other data layers. The data layers are separated by a nonmagnetic spacer layer (SL) and each data layer is formed of high-anisotropy (Ku) material so that the coercivities of lower and upper data layers (RL1 and RL2) are greater than the magnetic write field. At a high laser power both RL1 and RL2 are heated to above their respective Curie temperatures and data is recorded in both RL1 and RL2. At low laser power only upper RL2 is heated to above its Curie temperature and data is recorded only in RL2. The SL prevents lower RL1 from being heated to above its Curie temperature at low laser power.

Abstract: A heat-assisted magnetic recording (HAMR) disk drive has a disk with at least two independent data layers (RL1 and RL2), each data layer storing an independent data stream. At a high laser power both RL1 and RL2 are heated to above their respective Curie temperatures and a first data stream is recorded in both RL1 and RL2. At a lower laser power only upper RL2 is heated to above its Curie temperature and a second data stream is recorded only in RL2. The data layers are separated by a nonmagnetic spacer layer (SL) that prevents lower RL1 from being heated to above its Curie temperature at low laser power. The first and second data streams are typically asynchronous. Recorded data is read back from both data streams simultaneously as a composite readback signal. A joint Viterbi detector detects the asynchronous data streams simultaneously from the composite readback signal.

Abstract: A computer-implemented method includes: detecting a read access to one or more data tracks of a target data storage module; and setting a value of one or more bits in response to detecting the read access to the one or more data tracks, each of the one or more bits being associated with one of the one or more data tracks. The value of the one or more bits is set to a value configured to prevent a copy-on-write operation being applied to the one or more data tracks to which the read access was detected. Corresponding systems and computer program products are similarly disclosed, all of which advantageously improve storage system performance by reducing I/O bandwidth via preventing unnecessary copy operations.

Abstract: Method and apparatus for storing and retrieving user data from magnetic recording tracks in a data storage device. In some embodiments, a rotatable data recording medium has a circumferentially extending data track formed from spaced apart embedded servo wedges that extend radially across a recording surface of the medium to define intervening data wedges between each adjacent pair of the servo wedges. Each data wedge along the data track has only a single timing field at a beginning portion of the data wedge immediately adjacent a first servo wedge, followed by a plurality of data sectors that extend across the data wedge to an end portion of the data wedge immediately adjacent a second servo wedge. No inter-sector gaps are provided between the respective data sectors and no additional timing fields are provided between the first and second servo wedges.

Abstract: A method for writing data from a table to a tape includes setting a number of partitions on the tape, where the number of partitions is greater than or equal to a number of columns of the table to be written to the tape, and writing data from each column of the table to at least one partition of the tape, the at least one partition including two or more wraps, the data is written from a top of the two or more wraps towards a bottom of the two or more wraps in a direction of a width of the at least one partition. The written data is reciprocated from a beginning of the tape to an end of the tape in a longitudinal direction of the tape such that writing of a last data entry of one column ends at a beginning of the two or more wraps.