Invention Grant
- Patent Title: Proximity detection method for magnetic head and recording medium
- Patent Title (中): 磁头和记录介质的接近检测方法
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Application No.: US12504430Application Date: 2009-07-16
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Publication No.: US08018669B2Publication Date: 2011-09-13
- Inventor: Richard M. Ehrlich , Craig L. Tomita
- Applicant: Richard M. Ehrlich , Craig L. Tomita
- Applicant Address: JP Tokyo
- Assignee: Kabushiki Kaisha Toshiba
- Current Assignee: Kabushiki Kaisha Toshiba
- Current Assignee Address: JP Tokyo
- Agency: Patterson & Sheridan, LLP
- Main IPC: G11B27/36
- IPC: G11B27/36 ; G11B21/02

Abstract:
Touchdown between a read/write head of disk drive and a recording medium is detected based on the variance in the frequency domain of position error signals (PES), each of which is measured after incrementally positioning the read/write head closer to the recording medium, from a baseline PES. The synchronous portion of the baseline PES is quantified and removed from the baseline PES and subsequent PES measurements to remove the effect of the synchronous portion of the baseline PES. The non-synchronous portion of the PES measured at a particular read/write head position may also be removed by synchronously averaging multiple PES measurements for each read/write head position. Detection of touchdown may be based on the rate of change of the variance in the frequency domain of PES relative to a baseline PES, instead of the absolute value of the variance.
Public/Granted literature
- US20110013305A1 PROXIMITY DETECTION METHOD FOR MAGNETIC HEAD AND RECORDING MEDIUM Public/Granted day:2011-01-20
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