Patent US4907211A successfully refreshed from Google Patents.
US4907211A
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Magneto-optical recording apparatus having an inversion signal detecting means
Assignee: Sony Corp
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Filing: 1987-07-16
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Granted: 1990-03-06
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Expires: 2007-07-16
Abstract
Abstract The present invention relates to a magneto-optical recording apparatus, for example, as shown in FIG. 3, which is capable of rewriting information written in a magneto-optical recording medium by overwriting, wherein the magneto-optical recording medium 1 is irradiated with a laser light LB corresponding to an information signal only when the magneto-optical recording medium 1 is applied with a magnetic field sufficient to invert the magnetizing direction of the magneto-optical recording medium 1, whereby a noise-up region is prevented from being formed and high density recording can be satisfactorily carried out.
Inventors
- 👤 Hideyoshi Horimai
- 👤 Yoshio Aoki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:27
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/10502; G11B11/10528; G11B11/10504; G11B11/1051; G11B11/1053; G11B11/10532; G11B11/10534; G11B11/10536; G11B5/00; G11B5/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
141 words
A magneto-optical recording apparatus for recording and reproducing information on a magneto-optical recording medium having a perpendicular magnetization direction, comprising: Laser means for emitting a light beam onto the recording medium; Magnetic field biasing means, responsive to a magnetic field modulating means, for generating a magnetic field modulated in accordance with binary information signals; A light modulating means, receiving an inversion signal corresponding to an inversion of the magnetic biasing field, for providing a current to drive said laser, only during, the magnetic recording medium is applied with a magnetic field sufficient to invert the magnetization direction of the recording medium but not during the inversion of the magnetic biasing field; A signal inversion detecting means, receiving the binary information signals, for detecting the inversion of the magnetic biasing field and for inputting the inversion signal into the light modulating means.
Claim 2
Dependent Claim
141 words
A magneto-optical recording apparatus for recording and reproducing information on a magneto-optical recording medium having a perpendicular magnetization direction, comprising: Laser means for emitting a light beam onto the recording medium; Magnetic field biasing means, responsive to a magnetic field modulating means, for generating a magnetic field modulated in accordance with binary information signals; A light modulating means, receiving an inversion signal corresponding to an inversion of the magnetic biasing field, for providing a current to drive said laser, only during, the magnetic recording medium is applied with a magnetic field sufficient to invert the magnetization direction of the recording medium but not during the inversion of the magnetic biasing field; A signal inversion detecting means, receiving the binary information signals, for detecting the inversion of the magnetic biasing field and for inputting the inversion signal into the light modulating means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-03-05 | 1993-09-04 | 1994-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-03-05 | 1997-09-04 | 1998-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-03-05 | 2001-09-04 | 2002-03-06 | $7700.00 | Window Closed / Lapsed |