Abstract: Method and apparatus for detecting a reference pattern in a transmitted bit sequence. A duration of a search window used to detect the reference pattern is adaptively adjusted in relation to a previous detection of the pattern. This is preferably carried out by using a first search window to initially detect the pattern, and then adjusting the first search window to provide a second search window to subsequently detect the pattern. Preferably, the search window is an elapsed period of time during which a transducer is swept adjacent a storage medium to detect the reference pattern. Servo data are preferably written as a sequence of adjacent spiral servo patterns, and the reference pattern is preferably detected each time to determine the relative location of the most recently written spiral. Preferably, a larger search window is used for initial spirals and a smaller search window is used for subsequently written spirals.

Abstract: Embodiments of the present invention allow for media erasure. Various embodiments allow for controlling an actuator based on feedback signal measurements and disk phase to seek a head across a surface of a disk systematically for an erasure operation. Also, in various embodiments, a substantially repeatable seek motion of a head across a stroke may be determined, and launch points at which the head is launched over a disk in the seek motion for erasing at least a portion of the disk are determined based on disk phase.

Abstract: A system for generating resonance mode information associated with a servo track writer system comprising a drive VCM, a drive arm assembly, an external VCM, an external arm assembly, and a mechanical connection between the external arm assembly and the drive arm assembly. The system of the present invention comprises a controller, a position sensor, and a processor. The controller is adapted to apply an injection signal to the drive VCM such that the injection signal causes movement of the external arm assembly through the drive arm assembly and the pushpin. The position sensor is configured to generate an output signal indicative of a position of the external arm assembly. The processor generates the resonance mode information based on the injection signal and the output signal.

Abstract: Servo writer apparatus and associated method for writing servo information to a data storage device. The servo writer has an external positioner configured for contactingly positioning the actuator in relation to the storage medium. The servo writer furthermore has a contact torque control with executable instructions stored in memory that operably changes the actuator torque in relation to a change in the external positioner torque.

Abstract: An apparatus is provided for writing reference patterns on a data storage disk of a disk drive. The disk is rotated by a spindle motor. A back EMF sense circuit generates a sequence of zero crossing signals from back EMF sensed on windings of the spindle motor over each revolution of the spindle motor. The sequence of zero crossing signals define a corresponding sequence of zero crossing periods of time between successive zero crossing signals. A Phase Locked Loop (PLL) circuit generates a timing signal in response to comparison of a feedback signal to the zero crossing signals. The PLL circuit also compensates for repeatable variation among the sequence of zero crossing periods over each revolution of the spindle motor so that the timing signal is substantially independent of the repeatable variation among the sequence of zero crossing periods. A recording pattern generator writes reference patterns on the disk in response to the timing signal as the disk is rotated by the spindle motor.

Abstract: The present invention is directed to a method and apparatus for modifying a spiral profile using reference tracks written onto a disk surface of a disk drive. In one embodiment, a disk drive includes a disk surface having both a read head and a write head associated therewith. A servo track writer is provided for moving the write head and the read head relative to the disk surface. The write head, under control of the servo track writer, is used to write both a first reference track near an outer diameter of the disk surface and a second reference track near an inner diameter of the disk surface. The servo track writer is used to move the write head according to a spiral profile when writing spiral servo information onto the disk surface, and the first and second reference tracks are used to modify the spiral profile.

Abstract: An apparatus and associated method for preconditioning an elastomeric stop member to create a stabilized reference position for a moveable member by repetitively biasing the moveable member against the stop member and using the stabilized reference position to initiate a writing of servo data by the moveable member to a storage surface.

Abstract: Embodiments of the present invention allow for media erasure. Various embodiments allow for controlling an actuator based on feedback signal measurements and disk phase to seek a head across a surface of a disk systematically for an erasure operation. Also, in various embodiments, a substantially repeatable seek motion of a head across a stroke may be determined, and launch points at which the head is launched over a disk in the seek motion for erasing at least a portion of the disk are determined based on disk phase.

Abstract: The present invention is directed to a method and apparatus for performing best head detection in a disk drive using reference tracks. In one embodiment, a disk drive includes a plurality of disk surfaces. Each disk surface has a read head and a write head associated therewith. A servo track writer is provided for moving each write head and each read head relative to their corresponding disk surfaces. Reference tracks are written onto each of the disk surfaces. The reference track from each disk surface is read by its corresponding read head to determine a best read head. In one embodiment, the servo track writer sweeps each read head across its corresponding reference track as the reference track is being read. In one embodiment, each reference track includes reference track patterns and the best read head is the read head that detects the most patterns.

Abstract: The present invention is directed to a method and apparatus for reducing velocity errors when writing spiral servo information onto a disk surface of a disk drive. In one embodiment, a servo track writer is provided for moving a write head at a controlled velocity. The write head is used to write spiral servo information onto a disk surface. The write head is moved, using the servo track writer, at an actual velocity trajectory to simulate writing one spiral of spiral servo information. Differences between the actual velocity trajectory and a desired velocity trajectory are measured on a control sample by control sample basis over a window of control samples. The differences are integrated over the window. A gain, associated with the servo track writer controlling the velocity of the write head, is adjusted using the integrated differences.

Abstract: An apparatus and associated method for preconditioning an elastomeric stop member to create a stabilized reference position for a moveable member by repetitively biasing the moveable member against the stop member and using the stabilized reference position to initiate a writing of servo data by the moveable member to a storage surface.

Abstract: Servo writer apparatus and associated method for writing servo information to a data storage device. The servo writer has an external positioner configured for contactingly positioning the actuator in relation to the storage medium. The servo writer furthermore has a contact torque control with executable instructions stored in memory that operably changes the actuator torque in relation to a change in the external positioner torque.

Abstract: Method and apparatus for detecting a reference pattern in a transmitted bit sequence. A duration of a search window used to detect the reference pattern is adaptively adjusted in relation to a previous detection of the pattern. This is preferably carried out by using a first search window to initially detect the pattern, and then adjusting the first search window to provide a second search window to subsequently detect the pattern. Preferably, the search window is an elapsed period of time during which a transducer is swept adjacent a storage medium to detect the reference pattern. Servo data are preferably written as a sequence of adjacent spiral servo patterns, and the reference pattern is preferably detected each time to determine the relative location of the most recently written spiral. Preferably, a larger search window is used for initial spirals and a smaller search window is used for subsequently written spirals.

Abstract: Track pitch for writing tracks on a disk is determined based on an available stroke across the disk. The available stroke is identified by searching across the disk for where information can be written and read. The track pitch is determined for writing tracks on the disk based on the available stroke across the disk. Tracks are written on the disk based on the determined track pitch.