Abstract: A head position control device controls the position of a head with respect to a disk where post code is assigned to a servo frame. Servo frames of a disk is constituted by a servo frame not having a post code recorded in an inner side zone and a servo frame having a post code recorded in an outer side zone. The device reads the servo frame, demodulates a current position from the servo frame, drives an actuator according to the modulated position, and controls the position of the head to a target position. While implementing a high TPI, the inspection time for post codes can be decreased with a servo frame occupying ratio in consideration of the data format.

Abstract: A hard disk drive comprises an actuator with independently movable arms and a printed circuit board with custom core electronic architecture. The drive also comprises one or more platters aggregating two or more platter surfaces whereupon data may be read from or written to by corresponding read/write heads. The independent-arm actuator and custom printed circuit board enable alternate or interleaving bits or blocks of data to be read or written simultaneously across a plurality of platter surfaces within the same physical drive.

Abstract: Methods and structures for a general purpose, discrete time sample, interval accumulating filter for measuring any of a plurality of parameters associated with operation of a digital read channel. The general purpose interval accumulating features and aspects hereof permit flexible configuration for measuring a variety of operational characteristics and parameters of a digital, discrete time sample, read channel. The interval accumulating filter may sense harmonic frequencies associated with mechanical and electrical noise in the read channel operation. Other features and aspects hereof permit monitoring of multiple signal frequencies of a read channel in a disk drive, error recovery of a bad sector in a disk drive, and measurement of numerous other operational aspects of a discrete time digital sample read channel.

Abstract: A data reading unit reads inner offset data from an offset reading in an inner direction toward a center of a storage medium and outer offset data from an offset reading in an outer direction toward a circumference of the storage medium. A data comparing unit compares the inner offset data and the outer offset data read by the data reading unit. A data-output control unit that outputs the read-data when a result of comparison by the data comparing unit indicates that the inner offset data matches the outer offset data.

Abstract: A disk drive includes a drive housing, a storage disk, a slider and a drive circuitry. The slider magnetically interacts with the storage disk, and includes a read/write head that is positioned to have an actual head-to-disk spacing greater than zero nanometers during rotation of the storage disk. The drive circuitry can determine and/or monitor the actual head-to-disk spacing at any time during the operation of the disk drive based on an amplitude or a change in the amplitude of a signal such as a variable gain amplifier signal. In one embodiment, the slider includes a slider mover that receives current via the drive circuitry and causes a deformation of a portion of the slider to change the head-to-disk spacing based on the amplitude of the signal.

Abstract: A hard disk drive that includes a voice coil motor controlled by a servo circuit. The servo circuit provides a sinusoidal driving signal that has two different harmonic frequencies. The dual harmonic waveform creates a voice coil motor jerk profile (derivative of acceleration) that is continuous. The continuous jerk profile reduces vibration and seek time of the drive.

Abstract: A calibration method for a fly on demand head of a hard disk drive. The method includes the steps of flying a head over a test track of a disk that is covered with a lubricant. A voltage is applied to a heating element of the head to move the head closer to the disk. The fly height of the head is then determined. The voltage can be incrementally varied until the head makes contact with the disk. This sequence can cause a modulated wear pattern in the lubricant of the disk. The voltage is terminated and the head is allowed to fly over the test track. The head is also moved to adjacent tracks on either side of the test track. A pressure gradient of the flying head moves the lubricant about the disk to mitigate the modulated wear pattern.

Abstract: Exemplary tape library architectures and methods for recording errors in a tape drive are described. One exemplar method may be implemented in a processor a tape drive controller. The method comprises receiving, in a tape drive controller, an external identifier associated with a tape cartridge, recording the external identifier in a memory location associated with the tape drive controller, and associating, in a subsequent error analysis routine, an error in the tape drive with the external identifier of the tape cartridge in the tape drive.

Abstract: A magnetic recording medium includes a servo area where servo data used for detecting a position of a magnetic head on a magnetic recording medium is recorded; and a writable data area, arranged side by side with the servo area in a track direction, on which user data is written by the magnetic head. The servo area includes a preamble area where a preamble recording pattern that represents data used for providing a clock synchronization of the servo data is formed by a plurality of magnetic sections; and a burst area where data used for detecting a relative position of the magnetic head with respect to a track center position of the servo data is recorded and on which a single burst recording pattern which is a layout pattern that tilts to the preamble recording pattern with a predetermined tilt angle is formed by a plurality of magnetic sections.

Abstract: A magnetic recording medium includes a servo area where servo data used for detecting a position of a magnetic head on a magnetic recording medium is recorded; and a writable data area, arranged side by side with the servo area in a track direction, on which user data is written by the magnetic head. The servo area includes a preamble area where a preamble recording pattern that represents data used for providing a clock synchronization of the servo data is formed by a plurality of magnetic sections; and a burst area where data used for detecting a relative position of the magnetic head with respect to a track center position of the servo data is recorded and on which a single burst recording pattern which is a layout pattern that tilts to the preamble recording pattern with a predetermined tilt angle is formed by a plurality of magnetic sections.

Abstract: A magnetic recording medium includes a servo area where servo data used for detecting a position of a magnetic head on a magnetic recording medium is recorded; and a writable data area, arranged side by side with the servo area in a track direction, on which user data is written by the magnetic head. The servo area includes a preamble area where a preamble recording pattern that represents data used for providing a clock synchronization of the servo data is formed by a plurality of magnetic sections; and a burst area where data used for detecting a relative position of the magnetic head with respect to a track center position of the servo data is recorded and on which a single burst recording pattern which is a layout pattern that tilts to the preamble recording pattern with a predetermined tilt angle is formed by a plurality of magnetic sections.

Abstract: A magnetic recording medium includes a servo area where servo data used for detecting a position of a magnetic head on a magnetic recording medium is recorded; and a writable data area, arranged side by side with the servo area in a track direction, on which user data is written by the magnetic head. The servo area includes a preamble area where a preamble recording pattern that represents data used for providing a clock synchronization of the servo data is formed by a plurality of magnetic sections; and a burst area where data used for detecting a relative position of the magnetic head with respect to a track center position of the servo data is recorded and on which a single burst recording pattern which is a layout pattern that tilts to the preamble recording pattern with a predetermined tilt angle is formed by a plurality of magnetic sections.

Abstract: A magnetic recording medium includes a servo area where servo data used for detecting a position of a magnetic head on a magnetic recording medium is recorded; and a writable data area, arranged side by side with the servo area in a track direction, on which user data is written by the magnetic head. The servo area includes a preamble area where a preamble recording pattern that represents data used for providing a clock synchronization of the servo data is formed by a plurality of magnetic sections; and a burst area where data used for detecting a relative position of the magnetic head with respect to a track center position of the servo data is recorded and on which a single burst recording pattern which is a layout pattern that tilts to the preamble recording pattern with a predetermined tilt angle is formed by a plurality of magnetic sections.

Abstract: A magnetic recording medium includes a servo area where servo data used for detecting a position of a magnetic head on a magnetic recording medium is recorded; and a writable data area, arranged side by side with the servo area in a track direction, on which user data is written by the magnetic head. The servo area includes a preamble area where a preamble recording pattern that represents data used for providing a clock synchronization of the servo data is formed by a plurality of magnetic sections; and a burst area where data used for detecting a relative position of the magnetic head with respect to a track center position of the servo data is recorded and on which a single burst recording pattern which is a layout pattern that tilts to the preamble recording pattern with a predetermined tilt angle is formed by a plurality of magnetic sections.

Abstract: A magnetic recording medium includes a servo area where servo data used for detecting a position of a magnetic head on a magnetic recording medium is recorded; and a writable data area, arranged side by side with the servo area in a track direction, on which user data is written by the magnetic head. The servo area includes a preamble area where a preamble recording pattern that represents data used for providing a clock synchronization of the servo data is formed by a plurality of magnetic sections; and a burst area where data used for detecting a relative position of the magnetic head with respect to a track center position of the servo data is recorded and on which a single burst recording pattern which is a layout pattern that tilts to the preamble recording pattern with a predetermined tilt angle is formed by a plurality of magnetic sections.

Abstract: A controller includes a combining module that generates a total control signal for the drive device of a disk drive by combining a feedback control signal and a feedforward control signal. A feedback control module generates the feedback control signal in response to at least one state of the drive device. A feedforward control module generates the feedforward control signal based on a smoothing function and a feedforward control function. The smoothing function is determined by evaluating a plurality of candidate smoothing functions by determining a smoothness factor associated with the control signal that results from each of the plurality of candidate smoothing functions, and selecting the smoothing function as one of the plurality of candidate smoothing functions, based on the smoothness factor.

Abstract: A system and method for determining head-disk contact (HDC) in a disk drive uses the signal from the magnetoresistive (MR) read head and does not require the presence of magnetic transitions on the disk. The method thus has application in head-disk testers or “spin stands” to facilitate the design and testing of slider-suspension assemblies and fly-height actuators, as well as in disk drives to take corrective action before HDC and/or to control fly-height actuators. The invention is also a magnetic recording disk drive that has a fly-height actuator and a low-pass filter and comparator circuit for the MR signal. When the output of the filter exceeds a threshold the comparator circuit output indicates the onset of HDC. The comparator circuit output is input to a digital processor or controller. When the controller determines the onset of HDC or that HDC has occurred, it generates a control signal that can be used to cause the disk drive to take corrective action.

Abstract: A read/write device for a disk drive is disclosed. The read/write device includes a pre-amplifier and a recording head. The read/write device also includes a write signal path between the pre-amplifier and the recording head. The write signal path includes a write current. The read/write device also includes a read signal path between the pre-amplifier and the recording head. The read signal path includes an induced current related to the write current. The read/write device also includes a shunt path in the pre-amplifier to draw a part of the induced current from the read signal path.

Abstract: A disk drive and related methods are provided for tuning the control of an actuator for position mode seeking of a head between tracks on a disk based on a measured open loop response of the actuator. The disk drive includes a rotatable data storage disk, a head, an actuator, and a servo controller. The actuator positions the head relative to the disk responsive to a current command signal. The servo controller carries out a position mode seek of the head between tracks on the disk by generating the current command signal which is varied in response to a current feedforward signal that defines a head position profile during the seek, varied in response to a position response signal that defines an expected actuator movement response of the head to the current feedforward signal, and varied in response to a current feedback signal.

Abstract: A method of controlling a disk drive is disclosed that is capable of precise and real-time detection of an abnormal floating height of a magnetic head over an entire area of a magnetic disk. The method of controlling the disk drive includes the steps of: calculating a servo gain difference between a servo gain value obtained from a servo frame of the disk drive and a normal servo gain value recorded in the servo frame, the normal servo gain value being a servo gain value when a magnetic head flies normally relative to a magnetic disk; and forbidding the magnetic head writing data into the magnetic disk when the servo gain difference is equal to or greater than a predetermined value.