Western Digital Technologies, Inc.

Robert Lee Smith

Sukumar Rajauria

Erhard Theodor Schreck

Shaomin Xiong

John Thomas Contreras

Barry C Stipe

Takuya Matsumoto

Joey Martin Poss

Rehan Ahmed Zakai

Sripathi Vangipuram Canchi

Na Wang

Wan Kuang

Taiebeh Tahmasebi

The present disclosure generally relate to tape assembly implementations for magnetic recording devices, such as tape embedded drives (TEDs). In one or more embodiments, a first reel and a second reel are mounted at stationary positions. One or more of the first reel and/or the second reel includes a hub mounted to a spindle, and a single flange extending relative to the hub. In one or more embodiments, one or more of a first reel and/or a second reel each includes a flangeless hub mounted to a spindle.

Tape assemblies having flangeless reel configurations and single flange reel configurations for magnetic recording devices

The present disclosure generally relates to a multi-disk drive comprising a plurality of media surfaces and a plurality of heads, wherein a head of the plurality of heads is configured to be actuated over each surface of the plurality of media surfaces. The multi-disk drive further comprises control circuitry configured to write data to a first media surface of the plurality of media surfaces using a first head of the plurality of heads, and after all of an available memory of the first media surface has been filled, write data to a second media surface of the plurality of media surfaces using a second head of the plurality of heads. The control circuitry is further configured to permanently disable write access to one or more media surfaces of the plurality of media surfaces, while continuing to permit read access to the plurality of media surfaces.

Full disk serpentine write path for tamper-proof disk drive

Various illustrative aspects are directed to a data storage device, comprising one or more disks; a head, configured to be positioned proximate to a disk surface among the one or more disks; a temperature sensor; and one or more processing devices. The one or more processing devices are configured to: detect, via the temperature sensor, a non-nominal heat dissipation of a portion of the head; and, in response to detecting the non-nominal heat dissipation of the portion of the head, mitigate the non-nominal heat dissipation of the portion of the head.

Data storage device with detection and mitigation of non-nominal head heat dissipation

The present disclosure generally relates to using a data timestamp and/or a read counter to prevent data from being re-read and signal that the data has been accessed. The write assist element in the write head can be utilized to degrade the data or an allocated marker after the data has been read. The degradation functions as a read counter to indicate how many times the data has been read. Additionally and/or alternatively, a timestamp can be utilized. The timestamp is updated each time that the data has been accessed. In so doing, it is possible to determine whether data in a data storage device has been accessed.

Data timestamp and read counter for magnetic recording devices

The present disclosure generally relates to tape assembly implementations for magnetic recording devices, such as tape embedded drives (TEDs). In one or more embodiments, one or more of a first reel and/or a second reel is laterally movable relative to a side wall of a casing of the tape assembly. In one or more embodiments, a drive assembly laterally moves the first reel and the second reel substantially simultaneously such that a spindle distance between a first spindle and a second spindle is substantially constant.

Tape assemblies having movable reel configurations for magnetic recording devices

A data storage device is disclosed comprising a head actuated over a magnetic media, wherein the head comprises a write element, a read element, a laser, and a near field transducer. An operating thermal gradient of the magnetic media is periodically measured at an operating power setting for the laser that achieves a target magnetic write width. When a slope of the operating thermal gradient exceeds a threshold, a test thermal gradient and magnetic write width of the magnetic media is measured at multiple power settings for the laser in order to detect a contamination of the near field transducer.

Data storage device detecting NFT contamination by measuring thermal gradient and magnetic write width

A method and system for determining slider-disk contact in a hard-disk drive (HDD) that has dual independent heaters for thermal fly-height control, and dual embedded contact sensors, includes dithering power to the two heaters at different frequencies. The HDD has the two contact sensors electrically connected to provide a single combined output signal in response to the dithering. The single combined output signal is analyzed to detect two signals at the two different frequencies. When either detected signal exceeds a predetermined touchdown threshold value, the values of heater power for the two heaters are recorded, indicating that that combination of heater power values corresponds to slider-disk contact.

Method and system for determining slider-disk contact in a magnetic recording disk drive with dual fly-height actuators

A system, according to one embodiment, includes: a near field transducer, a return pole, a main pole, a waveguide adjacent the near field transducer, wherein the waveguide extends away from the near field transducer along a direction perpendicular to a media facing surface, at least one cladding layer adjacent to the waveguide, an underlayer positioned behind the near field transducer with respect to the media facing surface, the underlayer extending away from the near field transducer along the direction perpendicular to the media facing surface, and a fill material at least partially surrounding the underlayer, the waveguide and the at least one cladding layer. The underlayer has a lower coefficient of thermal expansion than the fill material. Other systems, and methods are described in additional embodiments.

Using window underlayer structures to protect near field transducers on heat assisted magnetic recording heads

Disclosed herein are write heads for data storage devices, methods for making and using such write heads, and data storage devices comprising such write heads. A write head comprises a near-field transducer (NFT), a thermal sensor, and a shield disposed between the NFT and the thermal sensor, wherein the shield comprises a magnetic or conductive material, such as, for example, Cu, Ag, Au, Al, Rh, Ti, Cr, Mo, Fe, Co, or Ni or an alloy that includes Cu, Ag, Au, Al, Rh, Ti, Cr, Mo, Fe, Co, and/or Ni. In some embodiments, the thermal sensor comprises a first lead and a second lead, and the shield is connected to the first lead but not the second lead to provide heat sinking for the shield.

Electromagnetically-shielded near-field transducer thermal sensor for heat-assisted magnetic recording

A data storage device is disclosed comprising a head actuated over a disk, wherein the head comprises a fly height actuator (FHA). An FHA control signal is applied to the FHA, wherein the FHA control signal comprises a rectangular wave having a duty cycle in the range of ten percent to thirty percent. While applying the FHA control signal to the FHA, the head touching down onto the disk is detected.

Data storage device employing low duty cycle square wave to detect head touchdown

A data storage device is disclosed comprising a head actuated over a disk, wherein the head comprises a first sensor element and a second sensor element. When configured into a first single-ended mode, a bias signal is applied to the first sensor element to generate a first single-ended output signal based on a response of the first sensor element, and when configured into a second single-ended mode, the bias signal is applied to the second sensor element to generate a second single-ended output signal based on a response of the first sensor element. When configured into a differential mode, the bias signal is concurrently applied to the first sensor element and the second sensor element to generate a differential output signal based on a response of the first sensor element and the second sensor element.

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San Jose, CA, United States of America

Robert Lee Smith