Patent US1952162A successfully refreshed from Google Patents.
Patent US3671101A successfully refreshed from Google Patents.
US3671101A
Expired / Lapsed
US
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Light control material
Assignee: Individual
•
Filing: 1969-07-25
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Granted: 1972-06-20
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Expires: 1989-07-25
Abstract
Abstract A SHEET OF LIGHT TRANSMITTING MATERIAL IS POVIDED ON ITS LIGHT EXIT SIDE WITH A PLURALITY OF GEOMETRIC SURFACES, PREFERABLY RIGHT REGULAR HEXAGINAL PYRAMIDS, WHOSE SURFACES DEFINE AN ANGLE WITH THE PLANE OF SAID SHEET SUFFICIENT TO TOTALLY REFLECT ALL LIGHT RAYS ENTERING THE LIGHT ENTRANCE SIDE AT AN ANGLE OF INCIDENT EXCEEDING A GIVEN ANGLE AND WHICH HAVE NOT PASSED THROUGH THE SHEET.
Inventors
- 👤 Dan M Finch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 18:25
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/12
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-20 | 1975-12-20 | 1976-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-20 | 1979-12-20 | 1980-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-20 | 1983-12-20 | 1984-06-20 | $7700.00 | Window Closed / Lapsed |