US3799647A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Constant visibility electro-optic display
Assignee: Honeywell Inc
•
Filing: 1972-05-24
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Granted: 1974-03-26
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Expires: 1992-05-24
Abstract
Abstract A display utilizing electro-optic (EO) material and having two coincident modes of operation, reflective and emissive. A partially silvered mirror reflects external ambient light and also passes light emitted from an internal source of backlighting. The combined effects of the reflected and emitted light cause the contrast, and therefore the visibility, of the display to be relatively constant even though the ambient light conditions may be varying.
Inventors
- 👤 V Luft
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:49
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/03; G02F1/055; G02F1/0102; G02F1/0105
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
65 words
A display comprises: a first polarizer located toward the front of the display and exposed to ambient light; an electro-optic plate located behind the first polarizer and electroded so that selected areas of the plate can be electrically energized; a diffuse, partly transparent, non-depolarizing reflector located behind the plate; a second polarizer located behind the reflector; and, a light source located behind the second polarizer.
Claim 2
Dependent Claim
65 words
A display comprises: a first polarizer located toward the front of the display and exposed to ambient light; an electro-optic plate located behind the first polarizer and electroded so that selected areas of the plate can be electrically energized; a diffuse, partly transparent, non-depolarizing reflector located behind the plate; a second polarizer located behind the reflector; and, a light source located behind the second polarizer.
Claim 3
Dependent Claim
17 words
The display of claim 1 wherein the first and second polarizers are circular polarizers of opposite handedness.
Claim 4
Dependent Claim
18 words
The display of claim 1 wherein the first and second polarizers are elliptical polarizers and of opposite handedness.
Claim 5
Dependent Claim
15 words
The display of claim 1 wherein the first and second polarizers are parallel linear polarizers.
Claim 6
Dependent Claim
17 words
The display of claim 1 wherein the first pOlarizer is linear and the second polarizer is circular.
Claim 7
Dependent Claim
18 words
The display of claim 1 wherein the electro-optic plate is electroded with a set of parallel, line electrodes.
Claim 8
Dependent Claim
17 words
The display of claim 6 wherein the electrodes are horizontal and form a bar graph type display.
References Cited (Backward Citations)
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US2944463A
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US3501219A
Cited
US3502875A
Cited
US3644016A
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US3724938A
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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) | 1977-03-25 | 1977-09-24 | 1978-03-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-25 | 1981-09-24 | 1982-03-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-25 | 1985-09-24 | 1986-03-26 | $7700.00 | Window Closed / Lapsed |