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US4532454A
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US
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Electroluminescent display having dark field semiconducting layer
Assignee: Verizon Laboratories Inc
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Filing: 1983-09-16
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Granted: 1985-07-30
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Expires: 2003-09-16
Abstract
Abstract An electroluminescent display is constructed as a laminate with a transparent front electrode and a metallic rear electrode sandwiching a layer of electroluminescent phosphor. A layer of light absorbing semiconducting material is interposed between the phosphor layer and the rear electrode. The semiconducting layer functions as a dark field increasing the contrast of the display. Furthermore, the semiconducting layer may be used in the fabrication of driver circuits integral to the display.
Inventors
- 👤 Mohamed I. Abdalla
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:18
CPC Classifications
H; H05; H05B; H05B33/00; H05B33/12; H05B33/22
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
64 words
An electroluminescent display comprised of: a transparent substrate; at least one transparent electrode supported by said substrate; an electroluminescent laminate deposited over said transparent electrode; a polycrystalline semiconducting layer of Si, GaAs, Ge, or InP deposited upon said electroluminescent laminate; and at least one rear electrode deposited upon said semiconducting layer; said rear electrode optically isolated from said electroluminescent laminate by said semiconducting layer.
Claim 2
Dependent Claim
64 words
An electroluminescent display comprised of: a transparent substrate; at least one transparent electrode supported by said substrate; an electroluminescent laminate deposited over said transparent electrode; a polycrystalline semiconducting layer of Si, GaAs, Ge, or InP deposited upon said electroluminescent laminate; and at least one rear electrode deposited upon said semiconducting layer; said rear electrode optically isolated from said electroluminescent laminate by said semiconducting layer.
Claim 3
Dependent Claim
26 words
The device of claim 1 which includes at least two of said rear electrodes separated by a groove etched through one or more of said layers.
Claim 4
Dependent Claim
24 words
The device of claim 1 wherein the resistivity of the semiconducting layer is selected to reduce haloing and crosstalk by the addition of dopants.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-07-29 | 1989-01-28 | 1989-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-07-29 | 1993-01-28 | 1993-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-07-29 | 1997-01-28 | 1997-07-30 | $7700.00 | Window Closed / Lapsed |