Patent application number | Description | Published |
20100118426 | WRITE CLOCK CONTROL SYSTEM FOR MEDIA PATTERN WRITE SYNCHRONIZATION - A write clock control system comprises a clock controller that determines a phase offset based on a phase difference between a write clock signal and a media pattern corresponding to a given timing synchronization field being read, and a phase interpolator that produces an updated write clock signal by updating the phase of the write clock signal in accordance with control signals that are based on the phase offset signal. | 05-13-2010 |
20100118428 | INTERSPERSED PHASE-LOCKED LOOP FIELDS FOR DATA STORAGE MEDIA SYNCHRONIZATION - Techniques are described for providing media-referenced timing for operations on a data storage medium. In particular, Phase-Locked Loop (PLL) synchronization fields may be interspersed within data fields of the medium and may be read to obtain timing measurements. The PLL fields are illustratively pre-recorded at predetermined intervals on the medium and have a fixed number of dots of the bit patterned medium between the PLL fields. Phase and frequency of a write clock may be controlled based on the read PLL fields to translate the timing measurements from the PLL fields into phase and frequency corrections to synchronize the write clock to the data storage medium, | 05-13-2010 |
20100118429 | REDUCED READ/WRITE TRANSITION OVERHEAD FOR STORAGE MEDIA - A technique is described for reducing overhead in a magnetic medium utilizing interspersed timing synchronization fields. In particular, a reader reads timing synchronization fields interspersed within data fields of the medium to obtain timing measurements. The reader is separated from a writer by a distance greater than a distance of the reader to traverse a select timing synchronization field. As such, the writer may perform a direct current (DC) write to the medium to suspend transitional write operations while the reader is reading the select timing synchronization field, and/or while the writer is over a unipolar field (e.g., a timing synchronization field). | 05-13-2010 |
20100195235 | MEASUREMENT OF TRACK ECCENTRICITY ON BIT PATTERNED MEDIA - The eccentricity of tracks defined on a rotating bit patterned media are measured using a readback signal, and the measured eccentricity may be used to control centering of the disk relative to a rotational spindle and/or to control movement of a read/write head relative to a selected track on the disk. | 08-05-2010 |
20120113539 | SKEW COMPENSATION SIGNAL - The relative trajectory of a transducer head over bit-patterned media (BPM) may be skewed with respect to a down-track direction on the media (i.e., skew error). In order to resolve the skew error, the presently disclosed technology measures the skew error without adding additional patterning on the media. A detector circuit detects a sequential series of data bits on a storage media. The sequential series of data bits alternate between at least two tracks on the storage media. The sequential series of data bits are sent to a timing circuit, which sets a time stamp indicating when each data bit is received using, for example, a delay chain or a voltage ramp. A time elapsed between receiving a first data bit, a second data bit, and a third data bit is tracked. Transducer head skew is adjusted based on a signal containing the time elapsed between the bits. | 05-10-2012 |
20120154949 | BIPOLAR POSITION ERROR BURSTS WITH UNIPOLAR SERVO FIELDS - A storage medium has a first servo field having magnetic lands separated by nonmagnetic areas, the magnetic lands of the first servo field having a unipolar pattern. The medium further includes a second servo field having magnetic lands separated by nonmagnetic areas, the magnetic lands of the second servo field having a bipolar pattern. | 06-21-2012 |
20120273999 | METHOD FOR PATTERNING A STACK - The embodiments disclose a method for patterning a stack, including embedding servo patterns within a final template and creating positions of plural cross-tracked shifted position error signal (PES) fields incrementally from the embedded servo patterns on the final template. | 11-01-2012 |
20130155539 | EXTENDED SERVO MARK - An extended servo mark word is used when an error is detected from a servo mark. For example, a servo mark associated with a disk drive track may be detected during a data access operation. In response to an error in detecting the servo mark, at least one adjacent bit is evaluated together with the servo address mark to overcome the error. | 06-20-2013 |
20130250448 | Servo Grey Code Error Correction - The disclosure is related to systems and methods for servo Gray code error detection and correction. A device may include a circuit configured to 1) selectively implement a quality-based error correction system to determine an error in the servo Gray code and correct the error; 2) selectively implement a trajectory-based error correction system to determine an error in the servo Gray code and correct the error; or 3) implement any combination of a quality-based error correction system and a trajectory-based error correction system to determine an error in the servo Gray code and correct the error. | 09-26-2013 |
20140029396 | HEAT ASSISTED MAGNETIC RECORDING DEVICE WITH PRE-HEATED WRITE ELEMENT - An apparatus includes a write element configured to apply a magnetic field to write data on a portion of a heat-assisted magnetic recording media in response to an energizing current. An energy source is configured to heat the portion of the media being magnetized by the write element. A preheat energizing current is applied to the write element during an interval before writing the data to the portion of the media. The preheat energizing current does not cause data to be written to the media and brings at least one of the write element and driver circuitry into thermal equilibrium prior to writing the data on the portion. | 01-30-2014 |
20140268395 | QUIET FIELD AND SYNCHRONIZATION FIELD DATA FORMAT - Data format that allows for format-efficient data storage, particularly on bit-patterned media. The data format allows for variations in the data storage device, such as reader-to-writer gap variations. A medium can also have at least a pair of a synchronization field and a quiet field with a length greater than a length of the synchronization field. These can be implemented in a bit patterned media system. | 09-18-2014 |
20140268396 | DATA INTERSECTOR GAPS FOR DATA SECTOR FORMAT - A data format that allows for format-efficient data storage, particularly on bit-patterned media. The data format uses an intersector gap that is dimensioned relative to a physical dimension of a transducer. Further described is a data storage medium comprising transducer overhead, such as an intersector gap, interleaved with fragment overhead. Also described is a storage medium comprising intersector gaps that each include a write splice and extra symbols. | 09-18-2014 |
20140281061 | DATA ACCESS FORMATTER - The defined architecture allows for format-efficient data storage on bit-patterned media, while allowing for typical variations in the drive, such as reader to writer gap variations. The defined BPM architecture relaxes some timing requirements on real-time signaling from the formatter to the channel, while enabling bit-accurate alignment between data accesses and the media. | 09-18-2014 |
20150194182 | DESIGN REQUIREMENT RELAXATION FOR MULTIPLE READERS IN PRESENCE OF LARGE SKEW ANGLE RANGE - A readback signal from a first reader and a readback signal from a second reader are received, the first reader and the second reader configured to read two-dimensional data from at least one track of a recording media. A quality metric of the second reader is measured based on the readback signal. It is determined if the quality metric for the second reader is above a threshold. If the quality metric is above the threshold, the first reader and the second reader are used to read the data. | 07-09-2015 |
20150279419 | MULTI-SENSOR MEDIA DEFECT SCAN - Apparatus and method for detecting media defects using a multi-sensor transducer. In some embodiments, a first pattern is written to a first track on a rotatable storage media and a second pattern is written to a second track on the media. A first read sensor of a multi-sensor transducer senses the first pattern from the first track and a second read sensor of the multi-sensor transducer concurrently senses the second pattern from the second track. At least one storage media defect is detected responsive to the sensed first and second patterns. | 10-01-2015 |