Seagate Technology Incorporated

University of Florida Research Foundation Inc

Puskal Prasad Pokharel

Mustafa Can Ozturk

Riyan Alex Mendonsa

Barmeshwar Vikramaditya

Timothy Francis Ellis

Gary Ernest Hillukka

Jose Carlos Principe

Walter Richard Eppler

Joshua Ward Christensen

Rene Johannes Marinus Van De Veerdonk

Richard Lyle Keizer

Jon David Trantham

David Erich Tetzlaff

Thomas C Zirps

Patrick J Korkowski

Stephanie Hernandez

Rati Agrawal

Systems and methods for servo zone transition optimization are described. In one embodiment, the storage system device includes a disk drive and a controller. In some embodiments, the controller may be configured to assess at least one operation of a read/write head of the disk drive; and format, based at least in part on the assessing of the read/write head, a disk surface of the disk drive with a first servo zone, a second servo zone, and an overlap region extending between a start point of the second servo zone and an end point of the first servo zone. In some cases, the overlap region starts towards a disk inner diameter (ID) and ends towards a disk outer diameter (OD).

Servo zone transition optimization for disk drives

Servo zone transition optimization for magnetic disk recording devices

A hard disc drive includes a slider including a first reader and a second reader. The hard disc drive also includes a magnetic recording medium and a controller. The controller is configured to determine a distance between the slider and the magnetic recording medium based at least in part on amplitudes of read signals from both the first reader and the second reader.

Head media spacing using multiple readers

A servo sector on a disk is read via first and second readers that both span two or more user data tracks. The servo sector has a crosstrack width that spans the two or more user data tracks. The first reader provides a first signal based on detecting a total longitudinal field of the servo sector. The second reader provides a second signal based on detecting a total perpendicular field of the servo sector. A position error of the first and second readers is detected using. A value of the first signal can be used to detect a position error, detect a track-to-track phase error, and/or detect a Gray code error of a track ID field of the servo sector.

Multitrack servo marks with perpendicular and longitudinal magnetic fields

First and second read channel logic circuits are configured to process first and second signals communicated from respective first and second readers that simultaneously read from a magnetic disk. A first servo detection circuit generates a primary servo gate based on timing data from the first reader. The primary servo gate is used for processing the first signal via the first read channel logic. A second servo detection circuit that generates a secondary servo gate based on the primary servo gate and an adjustment value. The secondary servo gate is used for processing the second signal via the second read channel logic.

Primary and secondary servo timing gates used with simultaneously operating readers

At least a portion of a first servo mark is read using a first read head during a rotation of a disk, the rotation comprising no more than 360 degrees. At least a portion of a second servo mark is read using a second read head during the rotation of the disk. Tracking positions of the first read head and the second read head are determined during the rotation based on reading the first servo mark and the second servo mark.

Servo tracking using a single servo writing pass per track for multi sensors

An apparatus and associated methodology providing read channel circuitry having a signal equalizer that sends an equalized signal to a bit detector. The read channel circuitry is capable of sampling values of the equalized signal to identify a bit transition from among a predefined plurality of different bit transitions. The apparatus may have channel optimization (CO) logic that, based on the input signal and the sampling of the equalized signal, defines first values for a programmable parameter of the bit detector that substantially maximizes vector separations among vectors of waveform target samples corresponding to the predefined plurality of different bit transitions, while the CO logic also defines second values for a programmable parameter of the equalizer that substantially minimizes the mean squared separation of the equalized signal segment for each bit transition from the waveform target corresponding to that bit transition.

Jointly optimizing signal equalization and bit detection in a read channel

Implementations described and claimed herein includes a method comprising selecting a zone of one or more tracks on a disk drive having a plurality of magnetic sensors on a transducer head, determining a performance matrix related to the selected track zone, and selecting a first subset and a second subset of the plurality of magnetic sensors based on the determined performance matrix, wherein only the first subset of the plurality of magnetic sensors are used for data recovery in the selected track zone, and the second subset of the plurality of magnetic sensors are used for servo recovery.

Disk drive sensor selection

In a servo control loop, servo burst signals that are read from a plurality of servo burst patterns that include a split servo burst pattern contain frequency acquisition error. The frequency acquisition error is at least partially removed to generate a frequency acquisition error compensated position error signal (PES).

Reducing effect of frequency acquisition error in a position error signal responsive to split servo burst patterns

Two or more signals are read from two or more respective tracks of a disk drive recording medium using respective two or more read transducers co-located on a slider. The slider is aligned to the two or more tracks in response to the correlation between the two or more signals.

Processing servo data from two or more read transducers co-located on a slider

The disclosure is related to systems and methods of compensating for interference via a multi-reader system. A transducer or read/write head may include a write element and multiple read elements. A compensation circuit can be configured to process read signals from the multiple read elements to reduce noise within the read signals, such as caused by the writer being simultaneously active or for other reasons. The read signals may be combined to produce a compensated read signal that has less noise than the original read signals.

Compensating for interference via a multi-reader system

The disclosure is related to systems and methods for achieving improved servo Gray code error detection and correction. A device may include a circuit configured to read servo data that is encoded using a Gray code encoding scheme to produce servo Gray code, read one or more Check bits associated with the servo Gray code, determine whether a read or write head is positioned over a target data track based on the servo Gray code and the one or more Check bits, and execute a read or write operation when the read or write head is positioned over the target data track.

Servo gray code check bits

Servo data of one or more tracks of a disk are collected using first and second read transducers co-located on a slider. Redundant portions of the servo data collected by the first and second read transducers are compared, and at least part of the servo data validating or corrected based on comparing the redundant portions.

Apparatuses, devices, and systems are presented with servo and data pattern formation using multi-dot arrays. In one example, an apparatus may comprise a data storage medium including a first patterned array of dots of magnetic material, a second patterned array of dots of magnetic material, and a non-magnetic space located between the first patterned array and second patterned array. In another example, a system may comprise a processor configured to store data to a data storage medium, the data storage medium including a first dot composite including a first patterned array of dots of magnetic material, a second dot composite including a second patterned array of dots of magnetic material, and a non-magnetic space located between the first dot composite and second dot composite. An order in which a dot composite and a non-magnetic space occur may define the value of one bit.

Data storage mediums and devices having bit patterned media

The disclosure is related to systems and methods for servo Gray code error detection and correction. A device may include a circuit configured to 1) selectively implement a quality-based error correction system to determine an error in the servo Gray code and correct the error; 2) selectively implement a trajectory-based error correction system to determine an error in the servo Gray code and correct the error; or 3) implement any combination of a quality-based error correction system and a trajectory-based error correction system to determine an error in the servo Gray code and correct the error.

Growing community of inventors

Edina, MN, United States of America

Puskal Prasad Pokharel