Western Digital Assigned Thirteen Patents

Increasing media absorption efficiency
Western Digital LLC, Fremont, CA, has been assigned a patent (8,670,294) developed by seven co-inventors for systems and methods for “increasing media absorption efficiency using interferometric waveguides in information storage devices.”

The co-inventors are Zhong Shi, Dublin, CA, Shing Lee, Fremont, CA, Hongxing Yuan, San Ramon, CA, Sergei Sochava, Sunnyvale, CA, Ronald L. Allen, San Jose, CA, Yunfei Li, Fremont, CA, and Michael Morelli, San Jose, CA.

The abstract of the patent published by the U.S. Patent and Trademark Office states: “Systems and methods for increasing media absorption efficiency using interferometric waveguides in information storage devices are described. One such system for an interferometric waveguide assembly includes a light source, a first waveguide arm and a second waveguide arm, a splitter configured to receive light from the light source and to split the light into the first waveguide arm and the second waveguide arm, and a near field transducer (NFT) configured to receive the light from the first waveguide arm and the second waveguide arm, where the first waveguide arm and the second waveguide arm converge to form a preselected angle at a junction about opposite the splitter, and where the first waveguide arm and the second waveguide arm are configured to induce a preselected phase difference in the light arriving at the NFT.”

The patent application was filed on Feb. 17, 2012 (13/399,250).

Fabricating disk drive base
Western Digital Technologies, Inc., Irvine, CA, has been assigned a patent (8,667,667) developed by three co-inventors for a method “for fabricating a disk drive base for a disk drive.“

The co-inventors are Diep L. Nguyen, Castro Valley, CA, Jifang Tian, Fremont, CA, and Hongqi Li, Redwood City, CA.

The abstract of the patent published by the U.S. Patent and Trademark Office states: “A disk drive includes a disk drive base comprising a first metal material. The disk drive base may include a first opening and a first attachment feature to which a head actuator assembly pivot may be attached. A motor support may be embedded in the first opening in the disk drive base. The motor support consists of a second metal material having a damping coefficient higher than that of the first metal material. A rotary spindle may be attached to the motor support, and a disk may be attached to the rotary spindle.“

The patent application was filed on Jan. 13, 2011 (13/005,727).

Storage device generating redundancy for data path protection
of a parity sector
Western Digital Technologies, Inc., Irvine, CA, has been assigned a patent (8,671,250) developed by Patrick J. Lee, San Jose, CA, for a “storage device generating redundancy for data path protection of a parity sector.”

The abstract of the patent published by the U.S. Patent and Trademark Office states: “A data storage device is disclosed comprising a non-volatile memory. A write command is received comprising a first logical block address (LBA) and first user data, and a second LBA and second user data. The first LBA is mapped to a first physical block address (PBA) for addressing a first memory segment. The second LBA is mapped to a second PBA for addressing a second memory segment. First redundancy is generated in response to the first user data, second redundancy in generated in response to the second user data, and parity data is generated in response to the first and second user data. Third redundancy is generated in response to the parity data and in response to at least one of the first LBA and the first PBA and at least one of the second LBA and the second PBA.”

The patent application was filed on Dec. 15, 2011 (13/327,326).

Enhanced thermal expansion for HDDs
Western Digital LLC, Fremont, CA, has been assigned a patent (8,670,214) developed by two co-inventors for a method and system “for providing enhanced thermal expansion for HDDs.“

The co-inventors are Neil Knutson, Fremont, CA, and Yu Lo, Foster City, CA.

The abstract of the patent published by the U.S. Patent and Trademark Office states: “A method and system provide a magnetic read and/or write transducer for use in disk drive. A read transducer has an air-bearing surface (ABS) and includes a read sensor, a nonmagnetic gap, a heater, and an expander. The nonmagnetic gap is adjacent to a portion of the read sensor and has a first coefficient of thermal expansion (CTE). The heater heats a portion of the magnetic read transducer. The expander is adjacent to a portion of the nonmagnetic gap and has a second CTE greater than the first CTE. The write transducer includes a pole, a coil, an insulator adjacent to and for insulating the coil, a heater and an expander. The expander has a CTE greater than the insulator’s CTE.”

The patent application was filed on Dec. 20, 2011 (13/332,241).

Disk drive estimating repeatable runout of reference pattern
based on repeatable runout of phase error
Western Digital Technologies, Inc., Irvine, CA, has been assigned a patent (8,670,206) developed by three co-inventors for “disk drive estimating repeatable runout of reference pattern based on repeatable runout of phase error.“

The co-inventors are Siri S. Weerasooriya, Campbell, CA, Yilin Cai, Fremont, CA, and Jiangang Liang, San Jose, CA.

The abstract of the patent published by the U.S. Patent and Trademark Office states: “A disk drive is disclosed comprising head actuated over a disk comprising a reference pattern. The head is positioned at a first radial location, a first phase error is measured in response to the reference pattern at the first radial location, and a first repeatable runout (RRO) of the first phase error is measured. The head is positioned at a second radial location, a second phase error is measured in response to the reference pattern at the second radial location, and a second repeatable runout (RRO) of the second phase error is measured. The first and second RROs are processed to estimate an offset r.sub.0 representing a difference between an axial rotation of the disk and an axial rotation of the reference pattern.“

The patent application was filed on March 27, 2012 (13/431,691).

Hybrid drive changing power mode of disk channel
when frequency of write data exceeds threshold
Western Digital Technologies, Inc., Irvine, CA, has been assigned a patent (8,670,205) developed by two co-inventors for “hybrid drive changing power mode of disk channel when frequency of write data exceeds a threshold.”

The co-inventors are James N. Malina, Irvine, CA, and William B. Boyle, Lake Forest, CA.

The abstract of the patent published by the U.S. Patent and Trademark Office states: “A hybrid drive is disclosed comprising a disk channel including a head actuated over a disk, the disk comprising a plurality of data sectors, and a non-volatile semiconductor memory (NVSM) comprising a plurality of memory segments. Write commands are received from a host, wherein the write commands comprise write data. When a frequency of the write data exceeds a threshold, an operating mode of the disk channel is changed to change a power consumption rate of the disk channel.”

The patent application was filed on Sept. 29, 2010 (12/894,058).

Suspension tail design for HGA
Western Digital Technologies, Inc., Irvine, CA, has been assigned a patent (8,665,566) developed by two co-inventors for a “suspension tail design for a head gimbal assembly of a HDD.”

The co-inventors are Yih-Jen D. Chen, Fremont, CA, and Tzong-Shii Pan, San Jose, CA.

The abstract of the patent published by the U.S. Patent and Trademark Office states: “A method of assembling a head stack assembly of a magnetic storage drive is provided. The method includes attaching a flexible printed circuit (FPC) with a suspension tail of a head gimbal assembly, wherein the suspension tail includes a plurality of discrete segments positioned within a bonding area and other portions of a structural layer outside of the bonding area, and pressing tail bond pads of the suspension tail against corresponding ones of FPC bond pads of the FPC by bringing a single flat surface of a thermode in contact with each of the discrete segments.“

The patent application was filed on Dec. 20, 2011 (13/331,313).

HDD adjusting gain and offset of BEMF velocity sensor
during self writing of spiral tracks
Western Digital Technologies, Inc., Irvine, CA, has been assigned a patent (8,665,551) developed by four co-inventors for a “disk drive adjusting gain and offset of BEMF velocity sensor during self writing of spiral tracks.”

The co-inventors are Siri S. Weerasooriya, Campbell, CA, Brian P. Rigney, Louisville, CO, Edgar D. Sheh, and Brandon P. Smith, San Jose, CA.

The abstract of the patent published by the U.S. Patent and Trademark Office states: “A disk drive is disclosed comprising a disk, a head, and a voice coil motor (VCM) operable to actuate the head over the disk, wherein the VCM generates a back electromotive force (BEMF) voltage. At least one reference track is written on the disk, and the head is positioned near a first diameter of the disk. While moving the head from the first diameter toward a second diameter of the disk, the reference track is read and a first estimated state error is measured. While moving the head from the second diameter of the disk toward the first diameter of the disk, the reference track is read and a second estimated state error is measured. A gain and an offset of a velocity sensor are adjusted in response to the first and second estimated state errors.”

The patent application was filed on Dec. 22, 2011 (13/334,955).

HDD with added external labyrinth path during servo track writing
Western Digital Technologies, Inc., Irvine, CA, has been assigned a patent (8,665,555) developed by six co-inventors for a “disk drive with added external labyrinth path during servo track writing.”

The co-inventors are Dana C. Fisher, Berthoud, CO, John R. Gustafson, Los Gatos, CA, Brian L. Rappel, Lyons, CO, Andrew A. Lucas, Lyons, CO, Scott E. Watson, San Jose, CA, and Lionel Young, San Francisco, CA.

The abstract of the patent published by the U.S. Patent and Trademark Office states: “A disk drive includes an enclosure that has a breather port therethrough. A first labyrinth path may be disposed inside the disk drive enclosure, in fluid connection with the breather port. A second labyrinth path may be temporarily disposed outside the disk drive enclosure, in fluid connection with the breather port. An alternative gas such as helium may be allowed to bleed out through the second labyrinth path during a period of servo track writing. The second labyrinth path may be removed after servo track writing.”

The patent application was filed on June 29, 2010 (12/826,474).

Storage device using metadata and mapping table
to identify valid user data on non-volatile media
Western Digital Technologies, Inc., Irvine, CA, has been assigned a patent (8,667,248) developed by Srinivas Neppalli, Irvine, CA, for a “storage device using metadata and mapping table to identify valid user data on non-volatile media.“

The abstract of the patent published by the U.S. Patent and Trademark Office states: “A data storage device is disclosed including a non-volatile media having a first and a second plurality of physical locations, the first plurality of physical locations storing user data and the non-volatile media storing first metadata associating each of the first plurality of physical locations with a logical block address (LBA), and a mapping table including a mapping of each LBA to a current physical location. The data storage device further includes control circuitry that reads the first metadata to obtain a first plurality of LBAs, reads the mapping table to determine a current physical location for the first plurality of LBAs, and compares the current physical location of each of the first plurality of LBAs to a corresponding one of the first plurality of physical locations to identify valid user data in the first plurality of physical locations for migration into the second plurality of physical locations.”

The patent application was filed on June 16, 2011 (13/162,035).

Head media separation from servo preamble in HDD
Western Digital Technologies, Inc., Irvine, CA, has been assigned a patent (8,654,466) developed by James P. R. McFadyen, Redwood City, CA, for a method of calculating “head media separation from servo preamble in a HDD drive.”

The abstract of the patent published by the U.S. Patent and Trademark Office states: “A method of calculating a Head Media Separation (HMS) from a preamble of embedded servo sectors in a disk drive may include steps of reading the preamble, the read preamble being amplified by a variable gain amplifier (VGA) set at a predetermined gain; transforming samples of the read preamble into a first and a second frequency using a discrete time-to-frequency domain transform such as a Discrete Fourier Transform (DFT); calculating the ratio of the magnitude of the discrete time-to-frequency domain transform of the first frequency to the magnitude of the discrete time-to-frequency domain transform of the second frequency; determining the HMS from the calculated ratio, and enabling the predetermined gain to be updated in synchronism with the transforming step.”

The patent application was filed on Nov. 21, 2011 (13/300,991).

Disk drive multiplexing read signal
and fly height signal to transmission line
Western Digital Technologies, Inc., Irvine, CA, has been assigned a patent (8,665,547) developed by three co-inventors for a “disk drive multiplexing read signal and fly height signal to a transmission line.”

The co-inventors are Piero Giaccone, Khoa Xuan Bui, San Jose, CA, and Teik Ee Yeo, Trabuco Canyon, CA.

The abstract of the patent published by the U.S. Patent and Trademark Office states: “A disk drive is disclosed comprising a disk comprising a plurality of servo tracks defined by servo sectors, and a head actuated over the disk, wherein the head comprises a read element operable to generate a read signal. The disk drive further comprises a fly height sensor operable to generate a fly height signal for the head, and control circuitry comprising a multiplexer operable to multiplex the read signal and the fly height signal to a transmission line. The multiplexer is configured to select the read signal when reading the servo sectors of a servo track, and configured to select the fly height signal when reading a segment of the servo track between consecutive servo sectors.”

The patent application was filed on Aug. 17, 2012 (13/588,999).

Hybrid drive writing extended ECC symbols to disk for data sectors stored
in non-volatile semiconductor memory
Western Digital Technologies, Inc., Irvine, CA, has been assigned a patent (8,683,295) developed by three co-inventors for “hybrid drive writing extended ECC symbols to disk for data sectors stored in non-volatile semiconductor memory.”

The co-inventors are Mei-Man L. Syu, Fremont, CA, Virgil V. Wilkins, Perris, CA, and Alan T. Meyer, Anaheim Hills, CA.

The abstract of the patent published by the U.S. Patent and Trademark Office states: “A hybrid drive is disclosed comprising a head actuated over a disk, and a non-volatile semiconductor memory (NVSM). A write command is received from a host, the write command comprising data. First and second ECC symbols are generated over the data, wherein the second ECC symbols are different than the first ECC symbols. The data and first ECC symbols are written to the NVSM, and the second ECC symbols are written to the disk.”

The patent application was filed on June 22, 2011 (13/166,728).