Marvell International Limited

Agency for Science, Technology and Research

Jingliang Zhang

Zhimin Yuan

Bo Liu

Guoxiao Guo

Siang Huei Leong

Chun Lian Ong

Anmin Kong

Songhua Zhang

Budi Santoso

Shiming Ang

Linlin Thi

Qing Li

Pantelis Sophoclis Alexopoulos

Wai Ee Wong

Zhimin He

Lin Thi Lin

Lin Lin Thi @ Htwe Htwe Yee

Branislav Hredzak

Abdullah Al Mamun

Weichun Ye

Eng Hong Ong

Lin Lin Thi

Lin Thi @ Htwe Htwe Yee Lin

Magnetic disk, method of track following on a magnetic disk, and method of writing a servo pattern in a dedicated servo layer of a magnetic disk. The magnetic disk comprises a servo pattern in a dedicated servo layer of the magnetic disk, the servo pattern having a first burst A and a second burst B arranged to be within one period of a servo sample, each of burst A and burst B comprising DC+ and DC&#x2212; magnetic bursts; wherein a center of the DC+/DC&#x2212; bursts of burst B is shifted relative to the DC+/DC&#x2212; bursts of burst A in a substantially radial direction of the magnetic disk.

Magnetic disk, method of track following on a magnetic disk, and method of writing a servo pattern in a dedicated servo layer of a magnetic disk

In the present disclosure, a method of operating a data storage apparatus is provided. The method includes writing a data signal into a portion of a data layer in a recording medium of a data storage apparatus. The method further includes determining a data layer coupling interference value arising due to interference from the data layer provided in between a sensor head and a servo layer of the recording medium in reading servo data, the data layer coupling interference value determined based on the data signal. The method further includes writing the data layer coupling interference value onto the recording medium. A corresponding data storage apparatus is provided.

Method of operating a data storage apparatus and data storage apparatus

A hard disk drive device and a method and apparatus for control of the hard disk drive is provided. The hard disk drive includes disk media, a slider head, a head gimbal assembly and a control means. The disk media includes at least two layers for data storage. The slider head flies above the disk media and includes a writer and a reader, and a head gimbal assembly supports the slider head above the disk media. The control means is physically coupled to the head gimbal assembly and electrically coupled to the writer and the reader for reducing write interference from the writer when the writer is writing to the disk media while the reader is reading from the disk media, wherein write interference is reduced in one or more of a time domain and a frequency domain.

Write interference reduction when reading while writing to a hard disk drive media

Various embodiments provide a recording medium. The recording medium may include: a dedicated servo layer for providing servo information, wherein the dedicated servo layer comprises a plurality of tracks, wherein a first track comprises a first servo signal of a first frequency, wherein a second track comprises a second servo signal of a second frequency, and wherein the first servo signal and the second servo signal comprise a common single tone signal.

Data recording medium, method for generating a reference clock signal, and data storage device

Various embodiments provide a recording medium. The recording medium may include a dedicated servo layer for providing servo information. The dedicated servo layer may include a plurality of tracks. A first track may include a first servo signal. A second track may include a second servo signal. The first servo signal and the second servo signal may include a plurality of common transitions. The transitions may be provided at a pre-determined frequency.

Data recording medium and method for generating a reference clock signal

In the present disclosure, a recording medium and a method of preparing a recording medium is provided. In a recording medium, a first annular servo track can be provided on a first layer of the recording medium, and second annular servo track can be provided on the first layer of the recording medium. The second annular servo track can be adjacent to the first annular servo track. In the recording medium, the first annular servo track and the second annular servo track are magnetically polarized and are magnetically opposing in polarity. A corresponding method of preparing a recording medium is provided.

Recording medium, a data storage apparatus and a method of preparing a recording medium

A system for tracking a position error of a read/write head. The read/write head is configured to read data recorded to a data layer of a recording medium and read servo information recorded to a dedicated servo layer of the recording medium. To read the servo information, the read/write head is configured to read, from a first track, a first servo signal including first servo bursts of a predetermined frequency, and read, from a second track adjacent to the first track, a second servo signal including second servo bursts of the predetermined frequency. The first servo bursts are orthogonal to the second servo bursts. A position error signal determination circuit is configured to determine the position error using at least one of the first servo signal and the second servo signal.

Systems and methods for determining a position error of a read/write head

According to embodiments of the present invention, a method for providing a synchronization signal for at least one of a read operation or a write operation carried out by means of a head in a data storage device is provided. The method includes obtaining a readback servo signal from a storage medium of the data storage device by means of the head, the readback servo signal having at least one frequency associated with a servo track of the storage medium, frequency mixing the readback servo signal with a local signal having a local frequency to provide a frequency mixed signal, and filtering the frequency mixed signal to provide the synchronization signal for at least one of the read operation or the write operation. According to further embodiments of the present invention, a data storage device is also provided.

Data storage device and a method for providing a synchronization signal for at least one of a read operation or a write operation carried out by means of a head in a data storage device

Various embodiments provide a data storage device. The data storage device includes a recording medium having a dedicated servo layer for providing servo information. The dedicated servo layer may include a plurality of servo patterns, wherein each servo pattern includes a preamble providing information for synchronization of at least one of a read and a write operation of the data storage device.

Data storage device and method for generating a reference clock signal for data storage device

According to various embodiments, a recording medium may be provided. The recording medium may include a dedicated servo layer configured to provide servo information. The dedicated servo layer may include a plurality of tracks. A first track may include a first servo signal. The first servo signal may include first servo bursts of a pre-determined frequency. A second track adjacent to the first track may include a second servo signal. The second servo signal may include second servo bursts of the pre-determined frequency.

Recording media, data storage devices, and methods for determining a position error signal in a recording medium

In various embodiments, a recording medium having a servo layer configured to provide servo information and a data recording layer configured to record data, wherein the medium comprises a plurality of servo patterns and a plurality of data segment in one sector, each data segment corresponding to each of the plurality of servo patterns, wherein the plurality of servo patterns comprises a first servo pattern comprising an automatic gain control, a second servo pattern comprising a sector address mark, a third servo pattern comprising a GrayCode, and a fourth servo pattern comprising a plurality of servo bursts, wherein the data recording layer is configured to record the data on the data segments corresponding to the first, second, third and fourth servo patterns.

Recording medium

A clock tracking circuit and method uses a clock compensation signal to compensate for timing marks on a media disk. The clock compensation signal may compensate for at least one of improper clock track closure and written-in jitter of the timing marks used to produce the measured clock signal. The clock compensation signal may be used to control a controllable oscillator used to generate the clock signal that thereby provides a compensated clock signal.

Disk drive clock tracking circuit, error compensation circuit and method

A method for computing position error signal information of a transducer in a data storage system provides for different readback signals between adjacent tracks. The method involves a computation to obtain coarse position information from the servo bursts signals for track seeking and a computation to obtain a position indicator from the user data sector for more precise track following within the user data sector.

Detection of track misregistration within user data channel

The present invention relates to controlling an actuator for positioning a read/write head in storage devices such as disk drives. More specifically, the invention relates to using a sensor to detect the disk vibration amplitude perpendicular to the disk surface, and using feed forward control to cancel or counteract the tendency of the read/write head to deviate off-track due to disk vibration. Various approaches are proposed to detect the disk vertical vibration.

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Singapore, Singapore

Jingliang Zhang