Dynamic magnetic information storage or retrieval – Monitoring or testing the progress of recording
Reexamination Certificate
2008-05-06
2008-05-06
Sniezek, Andrew L. (Department: 2627)
Dynamic magnetic information storage or retrieval
Monitoring or testing the progress of recording
C360S075000
Reexamination Certificate
active
07369341
ABSTRACT:
Firstly, in order to check the noise level of a device, DC erasure is applied to a magnetic recording medium and the magnetic recording medium is read. Then, a test signal including a first order component and a third order harmonic frequency is written into the magnetic recording medium. The written test signal is read and Fourier transform is applied to the read signal to obtain the respective amplitude of the first order and third order harmonic components. Then, it is determined whether the amplitude of the third order harmonic component is sufficiently large compared with the obtained noise level. If the amplitude is sufficiently large, the flying height of the head is estimated using both the first order and third order harmonic components. If the amplitude is not sufficiently large, the flying height of the head is estimated using only the first order component.
REFERENCES:
patent: 4777544 (1988-10-01), Brown et al.
patent: 5410439 (1995-04-01), Egbert et al.
patent: 6894854 (2005-05-01), Carlson et al.
patent: 2005/0152055 (2005-07-01), Biskeborn
patent: 5-20635 (1993-01-01), None
patent: 2004-14092 (2004-01-01), None
B. Liu, et al; “Tribo-Magnetics and Nanometer Spaced Head-Disk Systems;”IEEE Transactions on Magnetics; vol. 37; No. 2; Mar. 2001; pp. 918-923.
Iida Atsuo
Imamura Takahiro
Yokohata Toru
Fujitsu Limited
Kratz Quintos & Hanson, LLP
Sniezek Andrew L.
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