| Patent application number | Description | Published |
|---|
| 20090002871 | METHOD AND APPARATUS FOR HEAD POSITIONING USING SPIRAL SERVO PATTERNS IN A DISK DRIVE - According to one embodiment, a disk drive having a disk, a read head, a servo controller, and a CPU. In the disk, a multi-spiral servo pattern is recorded. The read head reproduces a hexagon-shaped detection signal from the multi-spiral servo pattern. The servo controller generates amplitudes values for respective frames, from the multi-spiral servo pattern. The CPU performs positional-error calculation by using the amplitude values for the frames. Upon detecting a positional change of the head is detected, the CPU performs the positional-error calculation by using the amplitude values generated at the time of replacing the frames with other frames, and corrects the positional error by adding an offset determined from the positional change of the head, to the result of the positional-error calculation. | 01-01-2009 |
| 20090002872 | METHOD AND APPARATUS FOR POSITIONING HEAD ON DATA TRACK WITH A VARIABLE TRACK WIDTH IN A DISK DRIVE - According to one embodiment, there is provided a disk drive has a controller that performs positioning control of a head on a data track with a variable track width. The disk drive has a disk in which concentric servo tracks are configured at regular intervals and in which the positions of the individual servo tracks and servo data including position information that enables a position in the range of a servo track width to be detected in units of a specific minimum offset are recorded. The controller performs positioning control of the head on a data track with a variable track width on the basis of the servo track. | 01-01-2009 |
| 20090002876 | METHOD AND APPARATUS FOR WRITING SERVO DATA, USING SPIRAL SERVO PATTERNS IN A DISK DRIVE - According to one embodiment, a servo-writing method for use in a disk drive, in which a CPU causes a head to record final patterns in a disk, by using the multi spiral servo pattern recorded in the disk. The CPU uses a designated spiral servo pattern, positioning the head at a target position, so that the head may write the final patterns at the target position and may read sector-address data contained in the final patterns. | 01-01-2009 |
| 20090003165 | METHOD AND APPARATUS FOR GENERATING SYNCHRONOUS CLOCK FOR WRITE OPERATION IN A DISK DRIVE - According to one embodiment, a disk drive configured to write data to a disk being rotated by a spindle motor has a synchronous clock generator that generates a synchronous clock to use during the write operation. The synchronous clock generator inputs the rotational acceleration of the spindle motor, as feed-forward control value, to the feedback control system provided in the drive disk, thereby generating a clock that is synchronous with the rotational speed of the disk. | 01-01-2009 |
| 20090168218 | DISK DRIVE DEVICE AND SERVO WRITE METHOD - According to one embodiment, a servo write module is configured to write radial servo patterns on the disk media using a first spiral servo pattern of the spiral servo patterns as a base pattern for tracing, to detect a shift amount of a sync mark position in each of other spiral servo patterns with respect to a sync mark position in the first spiral servo pattern, and to adjust, when the base pattern is switched from the first spiral servo pattern to a second spiral servo pattern of the spiral servo patterns, a phase of the servo write clock based on the detected shift amount corresponding to the second spiral servo pattern. | 07-02-2009 |
| 20090168225 | DISK DRIVE DEVICE AND HEAD POSITIONING CONTROL METHOD - According to one embodiment, a disk drive includes a detection signal producing module configured to produce a detection signal by reading each of the spiral servo patterns, the spiral servo patterns being read by a head while the head scans a circumferential direction region on the disk media. A position error computation module is configured to produce servo burst signals A, B, C, and D using a plurality of frames obtained by dividing the detection signal at even time intervals, at least one burst signal of the servo burst signals being produced using at least two frames in the frames, and to compute a position error of the head based on amplitude values of the produced burst signals. | 07-02-2009 |
| 20090168228 | DISK DRIVE HAVING A DISK OF DISCRETE-TRACK MEDIA TYPE - According to one embodiment, a disk drive has a DTM type disk. The DTM type disk has a servo area on one recording surface. In the servo area, a servo pattern is recorded. The servo pattern is composed of a projection-depression pattern and an N- and P-pole magnetic pattern. The N- and P-pole magnetic pattern is recorded in an address-data region that contains a cylinder code. | 07-02-2009 |
| 20100321810 | DISK DRIVE CONFIGURED TO CALCULATE HEAD REBOUND DISTANCE - According to one embodiment, a search module searches for a timing when a moving direction of a head changes in order to detect a first timing when the head collides against a stopper of a ramp during a head unload operation and a second timing when the head rebounds as a result of the collision. A calculation module calculates a rebound distance that the head has rebounded based on the first timing and the second timing. | 12-23-2010 |
