Phase-coherent in-line VCSEL array with slider trailing mount for HAMR

    公开(公告)号:US12040001B1

    公开(公告)日:2024-07-16

    申请号:US18230018

    申请日:2023-08-03

    发明人: Barry C. Stipe

    IPC分类号: G11B5/48 G11B13/08 G11B5/00

    摘要: The present disclosure relates to pretreating a magnetic recording head assembly for magnetic media drive. The magnetic recording head assembly comprises a slider having a media facing surface (MFS), a top surface disposed opposite the MFS, a trailing edge surface disposed adjacent to the top surface, and an optical grating disposed on the trailing edge surface. A vertical cavity surface emitting laser (VCSEL) device is mounted to the trailing edge surface of the slider. The VCSEL device is aligned with the optical grating. A magnetic recording head comprising a waveguide and a near field transducer (NFT) coupled to the waveguide is disposed on the trailing edge surface of the slider. The VCSEL device is capable of emitting a plurality of lasers that are phase coherent on to the optical grating. The optical grating is capable of directing the emitted lasers about 90 degrees to the waveguide.

    Noncontact communication device, magnetic tape drive, noncontact communication system, method for operating noncontact communication device, and program

    公开(公告)号:US12027186B2

    公开(公告)日:2024-07-02

    申请号:US18173783

    申请日:2023-02-24

    发明人: Eiichiro Kataoka

    IPC分类号: G11B5/00 G11B5/008 G11B15/67

    CPC分类号: G11B5/00813 G11B15/67

    摘要: A noncontact communication device includes a processor, and a transmission and reception device that applies a magnetic field to a noncontact storage medium mounted in a magnetic tape cartridge to induce power in the noncontact storage medium and is coupled to the noncontact storage medium by electromagnetic induction to perform transmission and reception of information with the noncontact storage medium. The noncontact storage medium has a measurement circuit that measures the power, and transmits power information regarding the power measured by the measurement circuit to the noncontact communication device. The transmission and reception device receives the power information, and the processor is configured to execute support processing of supporting the transmission and reception based on the power information received by the transmission and reception device.

    Direct measurement of magnetoresistive head resistance in a storage system

    公开(公告)号:US11978489B1

    公开(公告)日:2024-05-07

    申请号:US18319984

    申请日:2023-05-18

    IPC分类号: G11B5/00 G11B5/03 G11B5/39

    摘要: A computer program product, system, and method are provided for direct resistance measurement of a magnetoresistive (MR) head of a storage drive in a storage system. In one embodiment, a voltage difference across the MR reader head is measured directly by applying an AC current to the MR head to generate an AC voltage across the MR head that can propagate through filter capacitors and be measured. In one embodiment, the voltage difference is amplified and the peak-to-peak voltage at the output of the amplifier is captured. Similarly, a reference voltage difference across a reference resistance is measured directly by applying a reference AC current to a reference resistance. The resistance of an MR reader head may be calculated directly as a function of the respective voltage differences without including the resistance of any bias resistors biasing the MR head.

    Write signal interference cancellation across data/servo clock boundary

    公开(公告)号:US11967341B1

    公开(公告)日:2024-04-23

    申请号:US18344472

    申请日:2023-06-29

    IPC分类号: G11B5/00 G11B5/012 G11B20/10

    CPC分类号: G11B20/10009 G11B5/012

    摘要: A method for cancelling, from servo signals read in a read channel while a write channel is active, interference caused by write signals in the write channel, includes generating a predicted channel response signal from the write signals in a data clock domain, resampling the generated predicted channel response signal using a clock in the data clock domain having a rate corresponding to a servo clock from a servo clock domain, transferring the resampled predicted channel response signal from the data clock domain to the servo clock domain and aligning phase of the transferred resampled predicted channel response signal with phase of the servo clock, determining a domain-boundary-crossing delay incurred in the transferring, based on the domain-boundary-crossing delay, synchronizing the phase-aligned transferred resampled predicted channel response signal with the servo signals, and subtracting the synchronized phase-aligned transferred resampled predicted channel response signal from the servo signals.

    Magnetic recording device
    10.
    发明授权

    公开(公告)号:US11935568B2

    公开(公告)日:2024-03-19

    申请号:US18164120

    申请日:2023-02-03

    IPC分类号: G11B5/00 G11B5/31

    摘要: According to one embodiment, a magnetic recording device includes a magnetic head and a controller. The magnetic head includes first and second magnetic poles, a magnetic element provided between the first magnetic pole and the second magnetic pole, first and second terminals electrically connected to one end and another end of the magnetic element, respectively, and a coil. The controller is electrically connected to the magnetic element and the coil, and performs a recording operation. In the recording operation, the controller supplies a recording current to the coil while applying an element voltage between the first and second terminals. When the applied voltage is changed while the recording current is supplied, a differential resistance of the magnetic element becomes a first differential resistance peak when the applied voltage is a first voltage, and becomes a second differential resistance peak when the applied voltage is a second voltage.