Dynamic magnetic information storage or retrieval – Record transport with head stationary during transducing – Drum record
Patent
1988-06-28
1989-09-12
Wolfe, John H.
Dynamic magnetic information storage or retrieval
Record transport with head stationary during transducing
Drum record
360109, G11B 560
Patent
active
048665533
ABSTRACT:
In a magnetic disk apparatus according to the present invention, a slider has a sliding surface and a reflecting surface. The height of the reflecting surface from the magnetic disk is greater than that of the sliding surface from the disk, when the slider flies above the disk, so that there exists a minute difference in level between the sliding surface and the reflecting surface. The flying height of the sliding surface of the slider from the magnetic disk is measured. When the magnetic disk is rotated, the slider flies from the disk. In this state, a reference flying height, i.e., the flying height of the reflecting surface from the magnetic disk is measured by the optical interference process. Then, the minute difference is substracted from the measured reference flying height to obtain the flying height of the sliding surface of the slider from the magnetic disk. According to the invention, even if the minimum flying height of the sliding surface of the slider is shorter than 0.1 micrometer, the measurement can be effected by the optical interference process. In general, moreover, a minute flying height between a fixed datum plane and an object flying above the datum plane can be measured accurately.
REFERENCES:
patent: 3695767 (1972-10-01), George et al.
patent: 3855625 (1974-12-01), Garnier et al.
patent: 4081846 (1978-03-01), Roscamp et al.
patent: 4475135 (1984-10-01), Warner et al.
patent: 4651248 (1987-03-01), Shiiki et al.
patent: 4673996 (1987-06-01), White
Lin, "Techniques for the Measurement of Air-Bearing Separation-A Review", IEEE Transactions on Magnetics, vol. Mag. 9, No. 4, Dec. 1973.
IBM Technical Disclosure Bulletin, vol. 26, No. 9, Feb. 1984, pp. 4822-4823, Armonk, New York, U.S., W. Jaerisch et al., "Interferometric thickness measurement of very thin air gaps or films".
IBM Technical Disclosure Bulletin, vol. 24, No. 7A, Dec. 1981, p. 3174, Armonk, New York, U.S.; N.A. Feliss: "Measurement of Flying Height".
Kubo Masahiro
Ohtsubo Yasuo
Kabushiki Kaisha Toshiba
Wolfe John H.
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