Patent application number | Description | Published |
20110143169 | PERPENDICULAR MAGNETIC RECORDING DISK WITH ORDERED NUCLEATION LAYER AND METHOD FOR MAKING THE DISK - A continuous-media perpendicular magnetic recording disk with an oxide-containing granular Co alloy recording layer (RL) having minimal grain size dispersion has an ordered nucleation layer (ONL) formed below RL. The ONL has ordered nucleation sites arranged in a generally repetitive pattern. The nucleation sites are generally surrounded by non-nucleation regions of a different material than the nucleation sites. The Co-alloy grains of the subsequently deposited RL grow on the nucleation sites and the oxide of the RL become generally segregated on the non-nucleation regions. The ordered nucleation sites may be formed of a Ru-containing material and the non-nucleation regions may be formed of an oxide. The ONL is formed by nanoimprint lithography, preferably by a master mold fabricated with a method using self-assembling block copolymers for creating periodic nanometer scale features. | 06-16-2011 |
20120082015 | THERMALLY-ASSISTED RECORDING (TAR) PATTERNED-MEDIA DISK DRIVE WITH OPTICAL DETECTION OF WRITE SYNCHRONIZATION AND SERVO FIELDS - A thermally-assisted recording (TAR) bit-patterned-media (BPM) magnetic recording disk drive uses optical detection of synchronization fields for write synchronization and optical detection of servo sectors for read/write head positioning. The synchronization fields and servo sectors extend generally radially across the data tracks and are patterned into discrete nondata blocks separated by gaps in the along-the-track direction. A near-field transducer (NFT) directs laser radiation to the disk and generates a power absorption profile on the disk that has a characteristic along-the-track spot size less than the along-the-track length of the gaps between the nondata blocks in the synchronization fields and servo sectors. A sensor provides an output signal in response to radiation from the nondata blocks and gaps in the synchronization fields and servo sectors as the disk rotates to control the timing of the magnetic write field applied to the data islands and to control the positioning of the read/write head on the data tracks. | 04-05-2012 |
20130270221 | METHOD FOR IMPROVING A PATTERNED PERPENDICULAR MAGNETIC RECORDING DISK WITH ANNEALING - A method for making a bit-patterned-media magnetic recording disk with discrete magnetic islands includes annealing the data islands after they have been formed by an etching process. A hard mask, such as a layer of silicon nitride or carbon, may be first formed on the recording layer and a patterned resist formed on the hard mask. The resist pattern is then transferred into the hard mask, which is used as the etch mask to etch the recording layer and form the discrete data islands. After the data islands are formed by the etching process, the patterned recording layer is annealed. The annealing may be done in a vacuum, or in an inert gas, like helium or argon, or in a forming gas such as a reducing atmosphere of argon plus hydrogen. The annealing improves the coercivity, the effective saturation magnetization and the thermal stability of the patterned media. | 10-17-2013 |
20130329315 | SERVO CONTROL IN A PATTERNED-MEDIA MAGNETIC RECORDING DISK DRIVE USING A REFERENCE TABLE - A patterned-media magnetic recording disk drive has head positioning servo sectors on the disk that do not contain special patterns but merely use the same type of dots that are used for data. The “data” dots in angularly spaced sectors of the data tracks function as the servo sectors and are denoted as D-servo regions. The D-servo regions extend across an annular band of the disk, which may be a bootstrap band for self-servowriting. The dots in the annular band are randomly magnetized so that each track in each D-servo region provides a generally random readback signal at the data frequency. The precise radial and circumferential position of the read/write head within a D-servo region is determined by comparing the readback signal with a set of reference signal waveforms from a look-up reference table and finding the reference signal waveform that matches the readback signal. | 12-12-2013 |
20130342931 | MAGNETIC RECORDING DISK DRIVE WITH METHOD FOR DATA PRESERVATION DURING HIGH TRACK MISREGISTRATION (TMR) ENVIRONMENT - A hard disk drive (HDD) has a high track misregistration (TMR) mode of writing data. If the position error signal (PES) from the servo positioning information exceeds a first write inhibit threshold (WI- | 12-26-2013 |
20140139942 | MAGNETIC RECORDING DISK DRIVE WITH METHOD FOR RECOVERY OF DATA FROM FAILED DATA SECTORS - A magnetic recording disk drive determines the locations of defective bits in a failed data sector, and allows for the error correction code (ECC) to correctly decode the data from the sector. After a sector has failed decoding, the digitized waveform and the read channel state from the failed sector are stored in memory. A nondata pattern is written to the failed sector and read back to determine the locations of the defective data bits in the failed sector, which are then used to update the read channel state. The data pattern from the failed sector, with the identified bit error locations, is attempted to be decoded. If the decoding is successful then the sector is marked as bad and the correctly decoded data pattern is written to a different region of the disk, for example physical sectors specifically intended for use as spare sectors. | 05-22-2014 |
20140168807 | TEMPLATED GRANULAR MAGNETIC RECORDING MEDIA - A system and method for recording data to a perpendicular magnetic recording media having a highly ordered granular structure. The method includes the synchronization of write frequency and write phase to the granular structure of the magnetic media optimize performance of the magnetic data recording system by minimizing bit error rate. | 06-19-2014 |