US4249796A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Projection display device
Assignee: International Business Machines Corp
•
Filing: 1979-06-21
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Granted: 1981-02-10
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Expires: 1999-06-21
Abstract
Abstract A projection display device is provided in which variation in the index of refraction is used to modulate attenuated total reflection.
Inventors
- 👤 Glenn T. Sincerbox
- 👤 II Joseph G. Gordon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 03:20
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/19; G02F1/195
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
107 words
A projection display device comprising: (a) a prism having a base; (b) a thin film of material having a negative dielectric constant and having one side in optical contact with the base of said prism, and a second side; (c) a medium of variable refractive index in contact with said second side of said film; (d) means to pass a beam of light which is plane polarized in the plane of incidence onto the base of said prism at an angle to excite a surface electromagnetic wave at the interface between said medium and said film; and (e) means to vary the refractive index of said medium.
Claim 2
Dependent Claim
107 words
A projection display device comprising: (a) a prism having a base; (b) a thin film of material having a negative dielectric constant and having one side in optical contact with the base of said prism, and a second side; (c) a medium of variable refractive index in contact with said second side of said film; (d) means to pass a beam of light which is plane polarized in the plane of incidence onto the base of said prism at an angle to excite a surface electromagnetic wave at the interface between said medium and said film; and (e) means to vary the refractive index of said medium.
Claim 3
Dependent Claim
22 words
A device as claimed in claim 1 wherein the refractive index of the medium is varied by means of an electrochemical reaction.
Claim 4
Dependent Claim
22 words
A device as claimed in claim 1 wherein the refractive index of the medium is varied by means of a photochromic reaction.
Claim 5
Dependent Claim
20 words
A device as claimed in claim 1 wherein the refractive index of the medium is varied by means of electrochromism.
Claim 6
Dependent Claim
20 words
A device as claimed in claim 1 wherein the refractive index of the medium is varied by means of electrophoresis.
Claim 7
Dependent Claim
21 words
A device as claimed in claim 1 wherein the refractive index of the medium is varied by means of molecular reorientation.
Claim 8
Dependent Claim
16 words
A device as claimed in claim 1 wherein said surface electromagnetic wave is a surface plasmon.
Claim 9
Dependent Claim
16 words
A device as claimed in claim 1 wherein said surface electromagnetic wave is a surface polariton.
References Cited (Backward Citations)
DE674294C
Cited
US2185379A
Cited
US3307897A
Cited
US3476460A
Cited
US3612653A
Cited
US3730608A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-02-10 | 1984-08-11 | 1985-02-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-10 | 1988-08-11 | 1989-02-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-10 | 1992-08-11 | 1993-02-10 | $7700.00 | Window Closed / Lapsed |