Patent US3694054A successfully refreshed from Google Patents.
US3694054A
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Color display system utilizing plural birefringent elements having different retardances
Assignee: HAMPTON-HADDEN MARKETING Corp A CORP OF
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Filing: 1970-11-27
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Granted: 1972-09-26
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Expires: 1990-11-27
Abstract
Abstract A color-display system embodied in a clock mechanism wherein the face of the clock constantly changes color. A pair of transparent, light-polarizing sheets are arranged parallel to one another with one of the sheets forming the face of the clock. A pair of birefringent sheets are positioned between the polarizing sheets with one of the sheets having a greater retardance than the other. This one sheet is arranged with one of the principal axes at a fixed 45* angle relative to each of the polarizing axes. The other birefringent sheet is supported for rotation about an axis normal to the first birefringent sheet. Rotation of this birefringing sheet by the clock mechanism effectively changes the color of the clock face.
Inventors
- 👤 Jordan Kirsch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 23:13
CPC Classifications
G; G04; G04B; G04B45/00; G04B45/0023; G02; G02B; G02B27/00; G02B27/28; G02B27/288; G04B19/00; G04B19/30
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
105 words
A color-display system comprising a pair of lighttransmitting, polarizing sheets arranged parallel to one another, and each having a polarizing axis, a pair of birefringent sheet means, each interposed between said polarizing sheets and each having a set of principal axes, one of said birefringent sheet means having greater retardance than the other, said one sheet means being fixed relative to said polarizing sheets with one of its principal axes at an angle of 45* to the polarizing axes of each of the said polarizing sheets, and means for rotating said other birefringent sheet means about an axis normal to said one birefringent sheet means.
Claim 2
Dependent Claim
105 words
A color-display system comprising a pair of lighttransmitting, polarizing sheets arranged parallel to one another, and each having a polarizing axis, a pair of birefringent sheet means, each interposed between said polarizing sheets and each having a set of principal axes, one of said birefringent sheet means having greater retardance than the other, said one sheet means being fixed relative to said polarizing sheets with one of its principal axes at an angle of 45* to the polarizing axes of each of the said polarizing sheets, and means for rotating said other birefringent sheet means about an axis normal to said one birefringent sheet means.
Claim 3
Dependent Claim
20 words
A color display as set forth in claim 1 wherein said polarizing sheets have their axes perpendicular to each other.
Claim 4
Dependent Claim
20 words
A color display as set forth in claim 1 wherein said polarizing sheets have their axes parallel to one another.
Claim 5
Dependent Claim
21 words
A color display as set forth in claim 2 wherein said one birefringent sheet means has a retardance of 560 millimicrons.
Claim 6
Dependent Claim
21 words
A color display as set forth in claim 3 wherein said one birefringent sheet means has a retardance of 840 millimicrons.
Claim 7
Dependent Claim
32 words
A color display as set forth in claim 1 wherein said birefringent sheet means comprises a pair of birefringent sheets with each laminated, one to each of said pair of polarizing sheets.
Claim 8
Dependent Claim
36 words
A color display as set forth in claim 1 wherein said one birefringent sheet has a retardance which is a multiple of a half-cycle of phase delay for light at the center of the visible band.
Claim 9
Dependent Claim
40 words
A color display as set forth in claim 7 wherein said polarizing sheets have their axes fixed at angles of 90* relative to one another and said one birefringent sheet corresponds to even multiples of said half-cycle and below 6.
Claim 10
Dependent Claim
41 words
A color display as set forth in claim 7 wherein said polarizing sheets have their axes fixed at angles parallel to one another, and said birefringent sheet corresponds to odd multiples of said half-cycle above 1 and not higher than 7.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-09-26 | 1976-03-27 | 1976-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-26 | 1980-03-27 | 1980-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-26 | 1984-03-27 | 1984-09-26 | $7700.00 | Window Closed / Lapsed |