Patent application number | Description | Published |
20090009904 | Method for forming servo pattern and magnetic disk drive - Embodiments of the present invention provide a method of forming an initial servo-pattern for self servowrite, insusceptible to constraints of an output resolution of a driver circuit for driving an actuator, and a dynamic range. According to one embodiment, a cluster pattern made up of pattern blocks, each including a burst pattern, is written by use of a write element by pressing a head-support mechanism to a crash-stop, and a pattern block is newly written with a read element in states of being positioned at an inner peripheral side edge of the cluster pattern, an outer peripheral side edge thereof, and the center of two burst patterns included in the cluster pattern, respectively, thereby increasing a width of the cluster patterns in stages, so that an initial servo pattern for use in a propagation action is formed. | 01-08-2009 |
20100033868 | METHOD FOR WRITING SERVO PATTERNS AND DISK DRIVE INCLUDING A CONTROLLER FOR WRITING SERVO PATTERNS ACCORDING TO THE METHOD - A method for writing servo patterns onto a disk of a disk drive. The method includes providing a plurality of different drive currents for an actuator while pushing the actuator into a crash stop defining a swing range of the actuator. The method also includes performing a write operation for at least one of the plurality of different drive currents to write a plurality of servo pattern tracks including a plurality of separate servo pattern sectors. Furthermore, the method includes gradually changing a drive current of the plurality of different drive currents while pushing the actuator into the crash stop so as to gradually move a read element in searching for a servo pattern track to a radial position different from a radial position of the write element. Moreover, the method includes positioning the read element at one of the plurality of servo pattern tracks. | 02-11-2010 |
20110063751 | METHOD AND APPARATUS FOR POSITIONING A MAGNETIC-RECORDING HEAD - A method for positioning a magnetic-recording head. The method includes correcting amplitude of each burst signal of a plurality of burst signals read out with the magnetic-recording head from each respective burst pattern of a plurality of burst patterns. In addition, the method includes computing a deviation of the magnetic-recording head from a track based on corrected amplitudes of the plurality of burst signals. Moreover, the method includes positioning the magnetic-recording bead on the track based on the deviation of the magnetic-recording head. | 03-17-2011 |
20110080672 | METHOD FOR WRITING SERVO DATA TO A DISK AND DISK DRIVE CONFIGURED TO WRITE SERVO DATA UTILIZING THE METHOD - A method for writing servo sector sets that include a plurality of separate servo sectors on a disk so that servo sectors are present at same circumferential positions but different radial positions. The method includes reading a first servo sector set in a track with a read element such that the track includes first, second and third servo sector sets. The method also includes writing the third servo sector set with a write element at a different radial position from the read element with positional control and timing control using the first servo sector set while skipping the second servo sector set if all servo sectors of the first servo sector set are non-defective. Moreover, the method includes using positional control and timing control using the second servo sector set in the writing of the third servo sector set if the first servo sector set includes a defective servo sector. | 04-07-2011 |
20110141599 | Disk Drive And Method Of Writing Servo Write Tracks To A Disk - A system and method of writing servo write tracks to a rotating disk using a head having a read/write offset is disclosed. One embodiment utilizes a write element on the head to write the servo write tracks. A read element on the head is then positioned over the servo write tracks. The phase of a specific frequency component of the track shape error in the servo write track is measured during the positioning of the read element over the servo write track. A sine wave having a specific frequency and a phase is selected based on the measurement results. The sine wave is then applied to a servo system as a correction signal. A new servo write track is then written with the write element. | 06-16-2011 |
Patent application number | Description | Published |
20110188149 | SERVO PATTERNING COMPATIBLE WITH PLANARIZATION OF PATTERNED MAGNETIC DISKS - Embodiments herein illustrate patterned servo data that allows the patterned disk to be planarized with a relatively simple planarization process. A magnetic disk, in this regard, includes a data region having a plurality of tracks. The magnetic disk also includes a plurality of servo bursts patterned in the magnetic disk at a plurality of locations in each track. The servo bursts are operable to direct a controller to center a write head over a track in the data region and write a track identification. The servo bursts include magnetic lands and nonmagnetic grooves. The magnetic lands of the servo burst are generally configured with a uniform polarity of magnetization and a first uniform width. The nonmagnetic grooves are configured with a second uniform width. | 08-04-2011 |
20130010382 | PATTERNED MEDIA WITH AN ALTERNATING SERIES OF CONCENTRIC SERVO ZONES AND OVERLAP ZONES - Embodiments described herein provide for patterned media concentric zones with an alternating series of concentric servo zones and overlap zones. The overlap zones facilitate the writing of servo data between servo zones of different servo frequency. The overlap zones may be dual frequency zones. The dual frequency zones have a first set of overlap patterns with the substantially identical pattern as the bordering lower frequency servo zone and a second set of overlap patterns with the substantially identical pattern as the bordering higher frequency servo zone. A bootstrap zone can be included near the inner diameter to assist initial servo writing. Alternatively the overlap zones are bootstrap zones. Such bootstrap zones have both bootstrap patterns and overlap patterns, the overlap patterns have the substantially identical pattern as a bordering servo zone. Bootstrap patterns only require DC magnetization for servo operability. | 01-10-2013 |
20130010383 | PATTERNED MEDIA WITH AN ALTERNATING SERIES OF CONCENTRIC SERVO ZONES AND OVERLAP ZONES - Embodiments described herein provide for patterned media concentric zones with an alternating series of concentric servo zones and overlap zones. The overlap zones facilitate the writing of servo data between servo zones of different servo frequency. The overlap zones may be dual frequency zones. The dual frequency zones have a first set of overlap patterns with the substantially identical pattern as the bordering lower frequency servo zone and a second set of overlap patterns with the substantially identical pattern as the bordering higher frequency servo zone. A bootstrap zone can be included near the inner diameter to assist initial servo writing. Alternatively the overlap zones are bootstrap zones. Such bootstrap zones have both bootstrap patterns and overlap patterns, the overlap patterns have the substantially identical pattern as a bordering servo zone. Bootstrap patterns only require DC magnetization for servo operability. | 01-10-2013 |
20130010384 | SERVO PATTERN COMPATIBLE WITH PLANARIZATION CONSTRAINTS OF PATTERNED MEDIA AND USE OF A SINGLE MASTER TEMPLATE - Embodiments described herein provide for robust servo patterns that comply with planarization constraints and also allow use of a single master template for manufacture of both the front and back of a magnetic disk. Planarization constraints are met because only a portion of servo data is hard patterned on the magnetic disk and the hard patterned servo data areas comply with planarization constraints. The servo pattern has two symmetrical servo write assist patterns, one on each side of a central burst pattern. The servo sync, SAM, track-ID, sector-ID, and/or RRO values can be written magnetically by the write head onto these servo write assist patterns after the completion of the planarization process. The symmetric design of the servo pattern allows both a left-to-right and a right-to-left servo write and read back, thereby enabling use of a single master template in magnetic disk manufacture. | 01-10-2013 |
20130010385 | SERVO PATTERN COMPATIBLE WITH PLANARIZATION CONSTRAINTS OF PATTERNED MEDIA AND USE OF A SINGLE MASTER TEMPLATE - Embodiments described herein provide for robust servo patterns that comply with planarization constraints and also allow use of a single master template for manufacture of both the front and back of a magnetic disk. Planarization constraints are met because only a portion of servo data is hard patterned on the magnetic disk and the hard patterned servo data areas comply with planarization constraints. The servo pattern has two symmetrical servo write assist patterns, one on each side of a central burst pattern. The servo sync, SAM, track-ID, sector-ID, and/or RRO values can be written magnetically by the write head onto these servo write assist patterns after the completion of the planarization process. The symmetric design of the servo pattern allows both a left-to-right and a right-to-left servo write and read back, thereby enabling use of a single master template in magnetic disk manufacture. | 01-10-2013 |
20130010389 | PATTERNED MEDIA WITH AN ALTERNATING SERIES OF CONCENTRIC SERVO ZONES AND OVERLAP ZONES - Embodiments described herein provide for patterned media concentric zones with an alternating series of concentric servo zones and overlap zones. The overlap zones facilitate the writing of servo data between servo zones of different servo frequency. The overlap zones may be dual frequency zones. The dual frequency zones have a first set of overlap patterns with the substantially identical pattern as the bordering lower frequency servo zone and a second set of overlap patterns with the substantially identical pattern as the bordering higher frequency servo zone. A bootstrap zone can be included near the inner diameter to assist initial servo writing. Alternatively the overlap zones are bootstrap zones. Such bootstrap zones have both bootstrap patterns and overlap patterns, the overlap patterns have the substantially identical pattern as a bordering servo zone. Bootstrap patterns only require DC magnetization for servo operability. | 01-10-2013 |