CALCULATING A HEATER POWER THAT COMPENSATES FOR LASER INDUCED WRITER PROTRUSION FOR A HEAT-ASSISTED MAGNETIC RECORDING DEVICE

    公开(公告)号:US20200058323A1

    公开(公告)日:2020-02-20

    申请号:US16423594

    申请日:2019-05-28

    Inventor: Zhen Wei Hua Liu

    Abstract: A method includes moving a heat-assisted magnetic recording (HAMR) slider relative to a magnetic recording medium. The slider comprises a writer, a writer heater, and a near-field transducer (NFT). For each of a plurality of different head-to media spacings a test tone is written to a track of the medium, the test tone is read and a Discrete Fourier Transform (DFT) of an amplitude of the read test tone is captured. A first DFT curve is generated at a beginning of writing the test tones. A second DFT curve is generated at a saturated state of writing the test tones. An amount of horizontal shift between the first and second DFT curves is computed. The amount of horizontal shift corresponding to writer heater power required to compensate for NFT clearance offset due to laser induced writer protrusion.

    Calculating a heater power that compensates for laser induced writer protrusion for a heat-assisted magnetic recording device

    公开(公告)号:US10607646B2

    公开(公告)日:2020-03-31

    申请号:US16423594

    申请日:2019-05-28

    Inventor: Zhen Wei Hua Liu

    Abstract: A method includes moving a heat-assisted magnetic recording (HAMR) slider relative to a magnetic recording medium. The slider comprises a writer, a writer heater, and a near-field transducer (NFT). For each of a plurality of different head-to media spacings a test tone is written to a track of the medium, the test tone is read and a Discrete Fourier Transform (DFT) of an amplitude of the read test tone is captured. A first DFT curve is generated at a beginning of writing the test tones. A second DFT curve is generated at a saturated state of writing the test tones. An amount of horizontal shift between the first and second DFT curves is computed. The amount of horizontal shift corresponding to writer heater power required to compensate for NFT clearance offset due to laser induced writer protrusion.

    Calculating a heater power that compensates for laser induced writer protrusion for a heat-assisted magnetic recording device

    公开(公告)号:US10319400B1

    公开(公告)日:2019-06-11

    申请号:US16104214

    申请日:2018-08-17

    Inventor: Zhen Wei Hua Liu

    Abstract: A method includes moving a heat-assisted magnetic recording (HAMR) slider relative to a magnetic recording medium. The slider comprises a writer, a writer heater, and a near-field transducer (NFT). For each of a plurality of different head-to media spacings a test tone is written to a track of the medium, the test tone is read and a Discrete Fourier Transform (DFT) of an amplitude of the read test tone is captured. A first DFT curve is generated at a beginning of writing the test tones. A second DFT curve is generated at a saturated state of writing the test tones. An amount of horizontal shift between the first and second DFT curves is computed. The amount of horizontal shift corresponding to writer heater power required to compensate for NFT clearance offset due to laser induced writer protrusion.

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