US3671104A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for masking images by polarization
Assignee: Minolta Co Ltd
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Filing: 1970-11-12
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Granted: 1972-06-20
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Expires: 1990-11-12
Abstract
Abstract TWO DOUBLY REFRACTING PLATES WHOSE OPTIC AXES ARE AT 45* WITH EACH OTHER AND AN IMAGE-BEARING FILM ARE PLACED BETWEEN TWO OPTICAL POLARIZERS WHICH ARE SO DISPOSED THAT THEIR OPTIC AXES (PINCIPAL CRYSTALLOGRAPHIC AXES) ARE ROTATABLE. BY ROTATING THE OPTICAL POLARIZERS, THE POLARIZERS ARE SET AT SUCH POSITION THAT THEIR OPTIC AXES ARE AT A RIGHT ANGLE OR IN PARALLEL WITH EACH OTHER, WHILE AT THE SAME TIME EITHER ONE OF THE OPTICAL POLARIZERS AND EITHER ONE OF THE DOUBLY REFRACTING PLATES ARE SET IN SUCH POSITION THAT THEIR OPTIC AXES ARE AT AN ANGLE OF 45* WITH EACH OTHER. THUS, PART OF THE IMAGE CAN BE MASKED AS DESIRED.
Inventors
- 👤 Kuniki Seino
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:44
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/28
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 |