US5459701A
Expired / Lapsed
US
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Magneto-optical recording method
Assignee: Ricoh Co Ltd
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Filing: 1992-06-17
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Granted: 1995-10-17
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Expires: 2012-06-17
Abstract
Abstract A magneto-optical recording method is capable of carrying out overwriting on a magneto-optical recording medium including a single perpendicular magnetic layer serving as a recording layer, by applying laser beams thereto, thereby controlling the formation and erasure of magnetic domains, in which a magnetic domain with a desired length can be formed or erased by the application of a plurality of laser beams during the formation and erasure of the magnetic domains.
Inventors
- 👤 Toshiaki Tokita
- 👤 Motoharu Tanaka
- 👤 Atsuyuki Watada
- 👤 Yoshiko Kurosawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:14
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/10502; G11B11/1053; G11B11/10517
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
75 words
A magneto-optical recording method for overwriting on a magneto-optical recording medium comprising a single perpendicular magnetic layer serving as a recording layer, said method comprising applying, to said magnetic layer, laser beam pulses for forming and erasing magnetic domains, in which a plurality of laser beam pulses are applied to form a magnetic domain having a desired length and a plurality of laser beam pulses are applied to erase a region having a desired length.
Claim 2
Dependent Claim
75 words
A magneto-optical recording method for overwriting on a magneto-optical recording medium comprising a single perpendicular magnetic layer serving as a recording layer, said method comprising applying, to said magnetic layer, laser beam pulses for forming and erasing magnetic domains, in which a plurality of laser beam pulses are applied to form a magnetic domain having a desired length and a plurality of laser beam pulses are applied to erase a region having a desired length.
Claim 3
Dependent Claim
32 words
The magneto-optical recording method as claimed in claim 1, wherein a plurality of one type of laser pulses is applied during each of the formation or the erasure of said magnetic domain.
Claim 4
Dependent Claim
73 words
The magneto-optical recording method as claimed in claim 2, wherein the formation of said magnetic domain and the erasure thereof satisfy the relationships tw≧te, and Pw·tw>Pe·te, wherein Pw is the intensity of a laser pulse applied during the formation of said magnetic domain, tw is the pulse width thereof, and Pe is the intensity of a laser pulse applied during the erasure of said magnetic domain, and te is the pulse width thereof.
Claim 5
Dependent Claim
34 words
The magneto-optical recording method as claimed in claim 1, wherein a plurality of two types of laser pulses is combined and applied during each of the formation or the erasure of said magnetic domain.
Claim 6
Dependent Claim
30 words
The magneto-optical recording method as claimed in claim 4, wherein a first laser pulse of said laser pulses applied and a second and subsequent laser pulses are of different types.
Claim 7
Dependent Claim
122 words
The magneto-optical recording method as claimed in claim 5, wherein when the intensity of said first laser pulse applied during the formation of a magnetic domain is Pw1 and the pulse width thereof is tw1, and the intensity of said second and subsequent laser pulses applied during the formation of magnetic domains is Pw2 and the pulse width thereof is tw2, and when the intensity of said first laser pulse applied during the erasure of said magnetic domain is Pe1 and the pulse width is tel and the intensity of said second and subsequent laser pulses applied during the erasure of said magnetic domains is Pe2 and the pulse width thereof is te2; the relationships: Pw1<Pe1 Pw1·tw1>Pel·te1 Pw2=Pe2, and tw2=te2 are satisfied.
Claim 8
Dependent Claim
94 words
A magneto-optical recording method for overwriting on a magneto-optical recording medium comprising a single perpendicular magnetic layer serving as a recording layer, said method comprising applying, to said magnetic layer, a laser beam while varying the application conditions thereof in such a manner that the laser beam application interval (D) with respect to the moving direction along a track on the magneto-optical recording medium and the width (W) of a magnetic domain on the magneto-optical recording medium are in the relationship of 0.1 W≦D≦2.0 W, under the application of a predetermined external magnetic field.
Claim 9
Dependent Claim
94 words
A magneto-optical recording method for overwriting on a magneto-optical recording medium comprising a single perpendicular magnetic layer serving as a recording layer, said method comprising applying, to said magnetic layer, a laser beam while varying the application conditions thereof in such a manner that the laser beam application interval (D) with respect to the moving direction along a track on the magneto-optical recording medium and the width (W) of a magnetic domain on the magneto-optical recording medium are in the relationship of 0.1 W≦D≦2.0 W, under the application of a predetermined external magnetic field.
References Cited (Backward Citations)
US4610009A
Cited
US4907211A
Cited
US5170382A
Cited
US5200935A
Cited
US5323366A
Cited
US5218591A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-10-16 | 1999-04-17 | 1999-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-10-16 | 2003-04-17 | 2003-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-10-16 | 2007-04-17 | 2007-10-17 | $7700.00 | Window Closed / Lapsed |