Broadcom Corporation

Samsung Electronics Co., Ltd.

Maxtor Corporation

Benjamin Geunbae Ryu

Ara W Nazarian

Richard Koonwai Wong

King Wai Thomas Lau

Maxim Roth

A method determines RW head radial position relative to tracks within a magnetic data disc. This involves sensing both a S-burst signal and a P-burst signal with the RW head. The S-burst signal and P-burst signal are associated with a two-burst servo pattern on the magnetic disc. The S-burst pattern has a phase that remains constant radially across tracks within the magnetic disc. The P-burst has a second phase that rotates radially across tracks within the magnetic disc. By determining a phase difference between a sensed S-burst signal and P-burst signal, it is possible to determine the RW head radial position relative to the tracks on the magnetic disc.

Method for determining read/write head position based on phase detection of a servo pattern

A disk drive that contains a fly on demand head (FOD) and a process for determining contact between the FOD head and a disk. The head includes a heating coil that can receive various levels of power. The process may include a routine to determine head position estimate error data. Variance values for the estimate error data are generated for different power values and used to determine a contact point between the head and the disk. The process may also collect a plurality of signal amplification gain control (SAGC) signal values and compute an average of the SAGC values. Average SAGC values for different power levels can be generated and used to determine a contact point between the head and the disk.

Algorithm to detect the touch down of the flying head on disk

The present invention provides a method of generating magnetic reference patterns on a disk or other magnetic media. This involves writing a first magnetic reference pattern to the disk with a servo writer. The disk may then be transferred to a hard disk drive. Control circuitry within the hard disk drive may recognize the first magnetic reference pattern and then position a RW head within the hard disk drive based on the first magnetic reference pattern. As the RW drive is accurately positioned based on the first magnetic reference pattern a second magnetic reference pattern may be written to the disk using the RW head. The RW head location is determined based on the velocity and phase between the read-write head and servo setter marks contained within the first magnetic reference pattern.

Read write (RW) head position control for self servo writing process

A disk drive that contains a fly on demand head (FOD) and a process for determining contact between the FOD head and a disk. The head includes a heating coil that can receive various levels of power. The process includes using a routine to obtain head position estimate error data. A standard deviation of the estimate error data is then determined. Standard deviation values for estimate error data are generated for different power values and used to determine a contact point between the head and the disk.

Method to detect the touch down of the flying head on disk

A servo method and system for generating a position error signal in a disk drive including a magnetic data storage disk rotating relative to a base, a data transducer assembly positioned at concentric data tracks by a rotary actuator referenced to the base and controlled by a digital servo system, the data transducer assembly having a magnetoresistive (MR) read element, the digital servo system employing multiple servo bursts in servo sectors embedded within the data tracks. During servo track positioning/following for each target head position relative to a track, a plurality of the servo bursts are selected, and combinations of the burst amplitudes of the selected servo bursts are obtained. A substantially continuous position error signal (C_PES) is generated based on the combinations of the burst amplitudes, indicating radial position of the read head relative to the target position.

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Cupertino, CA, United States of America

Benjamin Geunbae Ryu