US4411495A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Refractive index switchable display cell
Assignee: AT&T Inc
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Filing: 1981-04-15
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Granted: 1983-10-25
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Expires: 2001-04-15
Abstract
Abstract A display cell having at least two states of different opacity, comprises a first material having a first index of refraction, a second material dispersed within the first material and having a second index of refraction, the difference between the first and the second indices of refraction being variable over a range of values, and means for varying the difference in index of refraction over a portion of the range. When the indices of refraction of the first and second material are substantially the same, the display is substantially transparent. Otherwise it is opaque or substantially less transparent.
Inventors
- 👤 Gerardo Beni
- 👤 Harold G. Craighead
- 👤 Susan Hackwood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:47
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/19; G02F1/195; G02F1/13; G02F1/133; G02F1/1333; G02F1/1334; G02F1/17; G02F1/172
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
110 words
A display cell which comprises: a first optically nonabsorbing material having a first index of refraction; a second optically nonabsorbing material dispersed within said first material and having a second index of refraction, the difference between said first and said second indices of refraction being variable over a range of values; and electrode means disposed about a portion of said first optically nonabsorbing material for establishing an electric field in said first and second optically nonabsorbing materials which changes said difference over a portion of said range, so that said display cell has varying degrees of opacity and each degree of opacity is substantially uniform over the visible light spectrum.
Claim 2
Dependent Claim
110 words
A display cell which comprises: a first optically nonabsorbing material having a first index of refraction; a second optically nonabsorbing material dispersed within said first material and having a second index of refraction, the difference between said first and said second indices of refraction being variable over a range of values; and electrode means disposed about a portion of said first optically nonabsorbing material for establishing an electric field in said first and second optically nonabsorbing materials which changes said difference over a portion of said range, so that said display cell has varying degrees of opacity and each degree of opacity is substantially uniform over the visible light spectrum.
Claim 3
Dependent Claim
16 words
A display in accordance with claim 1 wherein at least one of said electrodes is transparent.
Claim 4
Dependent Claim
17 words
A display in accordance with claim 2 wherein said second optically nonabsorbing material is an anistropic suspension.
Claim 5
Dependent Claim
18 words
A display in accordance with claim 2 wherein said second optically nonabsorbing material is a liquid crystal material.
Claim 6
Dependent Claim
19 words
A display in accordance with claim 2 wherein said second optically nonabsorbing material is a solution of anisotropic molecules.
Claim 7
Dependent Claim
17 words
A display in accordance with claim 2 wherein said second optically nonabsorbing material is a solid material.
Claim 8
Dependent Claim
14 words
A display in accordance with claim 6 wherein said solid material is Lithium Niobate.
Claim 9
Dependent Claim
113 words
A display cell which comprises: a first optically nonabsorbing material having a first index of refraction; a second optically nonabsorbing material dispersed within said first material and having a second index of refraction, the difference between said first and said second indices of refraction being variable over a range of values; electrode means disposed about a portion of said first optically nonabsorbing material for establishing an electric field in said first and second optically nonabsorbing materials which changes said difference over a portion of said range, so that said display cell has varying degrees of opacity; and said second optically nonabsorbing material is an anisotropic suspension comprising TiO 2 in H 2 O.
Claim 10
Dependent Claim
113 words
A display cell which comprises: a first optically nonabsorbing material having a first index of refraction; a second optically nonabsorbing material dispersed within said first material and having a second index of refraction, the difference between said first and said second indices of refraction being variable over a range of values; electrode means disposed about a portion of said first optically nonabsorbing material for establishing an electric field in said first and second optically nonabsorbing materials which changes said difference over a portion of said range, so that said display cell has varying degrees of opacity; and said second optically nonabsorbing material is an anisotropic suspension comprising TiO 2 in H 2 O.
Claim 11
Dependent Claim
116 words
A display cell which comprises: a first optically nonabsorbing material having a first index of refraction; a second optically nonabsorbing material dispersed within said first material and having a second index of refraction, the difference between said first and said second indices of refraction being variable over a range of values, said second optically nonabsorbing material being a liquid crystal material; and means for providing and varying a magnetic field disposed to pass through at least a portion of said liquid crystal material to change said difference over a portion of said range, so that said display cell has varying degrees of opacity and each degree of opacity is substantially uniform over the visible light spectrum.
Claim 12
Dependent Claim
116 words
A display cell which comprises: a first optically nonabsorbing material having a first index of refraction; a second optically nonabsorbing material dispersed within said first material and having a second index of refraction, the difference between said first and said second indices of refraction being variable over a range of values, said second optically nonabsorbing material being a liquid crystal material; and means for providing and varying a magnetic field disposed to pass through at least a portion of said liquid crystal material to change said difference over a portion of said range, so that said display cell has varying degrees of opacity and each degree of opacity is substantially uniform over the visible light spectrum.
Claim 13
Dependent Claim
99 words
A display cell which comprises: a first optically nonabsorbing material having a first index of refraction; a second optically nonabsorbing material dispersed within said first material and having a second index of refraction, the difference between said first and said second indices of refraction being variable over a range of values, said second optically nonabsorbing material being napthalene; and means for applying heat to said first and second optically nonabsorbing materials to cause a phase transition in said napthalene which changes said difference over a portion of said range, so that said display cell has varying degrees of opacity.
Claim 14
Dependent Claim
99 words
A display cell which comprises: a first optically nonabsorbing material having a first index of refraction; a second optically nonabsorbing material dispersed within said first material and having a second index of refraction, the difference between said first and said second indices of refraction being variable over a range of values, said second optically nonabsorbing material being napthalene; and means for applying heat to said first and second optically nonabsorbing materials to cause a phase transition in said napthalene which changes said difference over a portion of said range, so that said display cell has varying degrees of opacity.
References Cited (Backward Citations)
US2953819A
Cited
US3030852A
Cited
US3458249A
Cited
US3390933A
Cited
US3832033A
Cited
US4021846A
Cited
US3951520A
Cited
US3918794A
Cited
US3961181A
Cited
US4097128A
Cited
US4066335A
Cited
US4046456A
Cited
US4214819A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-10-24 | 1987-04-25 | 1987-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-24 | 1991-04-25 | 1991-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-24 | 1995-04-25 | 1995-10-25 | $7700.00 | Window Closed / Lapsed |