Patent US4654837A successfully refreshed from Google Patents.
US4654837A
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Magneto-optic transducer with enhanced signal performance
Assignee: Datatape Inc
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Filing: 1985-09-06
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Granted: 1987-03-31
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Expires: 2005-09-06
Abstract
Abstract A magneto-optic transducer for providing an optical indication of variations in magnetization in a magnetic storage medium located along a predetermined path. The transducer has a thin film of magneto-optic material with an edge positionable closely adjacent the storage medium path so that the magneto-optic film is magnetized in accordance with the magnetization in the storage medium. The magneto-optic film is supported such that polarized light projected along an incident optical path, convergent with the storage medium path at an acute angle, intercepts the magneto-optic film substantially normally and is reflected back generally along the incident optical path.
Inventors
- 👤 Lewis B. Browder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:57
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/10532; G11B11/10541; G11B11/10543; G11B11/10547
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
163 words
A magneto-optic transducer for providing an optical indication of variations in magnetization in a magnetic storage medium located along a predetermined path, said transducer comprising: a body portion for contacting the storage medium along the path, said body portion having a radius tip adjacent the storage medium path and a section extending from said radius tip in a direction divergent from the storage medium path; a thin film of magneto-optic material having an edge positioned at said radius tip so that said magneto-optic film is magnetized in accordance with the magnetization in the storage medium adjacent said radius tip; means for directing polarized light along an incident optical path convergent with said body portion section and the storage medium path at an acute angle; and means for supporting said magneto-optic film such that the incident polarized light intercepts said magneto-optic film substantially normally, is modulated in accordance with magnetization in said magneto-optic material, and is reflected generally back along said incident optical path.
Claim 2
Dependent Claim
163 words
A magneto-optic transducer for providing an optical indication of variations in magnetization in a magnetic storage medium located along a predetermined path, said transducer comprising: a body portion for contacting the storage medium along the path, said body portion having a radius tip adjacent the storage medium path and a section extending from said radius tip in a direction divergent from the storage medium path; a thin film of magneto-optic material having an edge positioned at said radius tip so that said magneto-optic film is magnetized in accordance with the magnetization in the storage medium adjacent said radius tip; means for directing polarized light along an incident optical path convergent with said body portion section and the storage medium path at an acute angle; and means for supporting said magneto-optic film such that the incident polarized light intercepts said magneto-optic film substantially normally, is modulated in accordance with magnetization in said magneto-optic material, and is reflected generally back along said incident optical path.
Claim 3
Dependent Claim
38 words
A magneto-optic transducer as defined in claim 1 wherein said thin film of magneto-optic material is of the Kerr effect type, whereby polarized light intercepting said magneto-optic film is reflected therefrom and has its plane of polarization rotated.
Claim 4
Dependent Claim
60 words
A magneto-optic transducer as defined in claim 1 wherein said thin film of magneto-optic material is of the Faraday effect type, and further comprising a reflective surface on said supporting means, whereby polarized light intercepting said magneto-optic film passes through said magneto-optic film, has its plane of polarization rotated, is reflected from said surface, and repasses through said magneto-optic film.
References Cited (Backward Citations)
US3474431A
Cited
US3465322A
Cited
US3636535A
Cited
US3626394A
Cited
US3665431A
Cited
US3739362A
Cited
US4228473A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-03-30 | 1990-09-29 | 1991-03-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-30 | 1994-09-29 | 1995-03-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-30 | 1998-09-29 | 1999-03-31 | $7700.00 | Window Closed / Lapsed |