Patent US4547702A successfully refreshed from Google Patents.
US4547702A
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Thin film electroluminscent display device
Assignee: Osram Sylvania Inc
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Filing: 1983-10-11
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Granted: 1985-10-15
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Expires: 2003-10-11
Abstract
Abstract An improved dark field material for use in a thin film electroluminescent display device that typically includes a transparent electrode layer, a segmented electrode layer and an electroluminescent phosphor layer between the electrode layers. The improved dark field layer is of a composition of a dielectric material such as the preferred magnesium oxide and a noble metal, which is preferably gold co-evaporated by way of an electron beam deposition technique. The preferred range of noble metal by volume is 6%-10%. By varying the noble metal content within this range, there is provided control of the operating temperature of the electroluminescent display device.
Inventors
- 👤 Martin P. Schrank
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:39
CPC Classifications
H; H01; H01B; H01B3/00; H01B3/02; H01B3/12; H05; H05B; H05B33/00; H05B33/12; H05B33/22
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
100 words
An electroluminescent display device comprising a transparent electrode layer, a segmented electrode layer, an electroluminescent phosphor layer disposed between said electrode layers, and a dark field layer of a composition of a dielectric material with a noble metal, wherein the percentage of noble metal by volume is in the range of 6%-10%, said dark field layer being interposed between said electroluminescent phosphor layer and said segmented electrode layer, said dark field layer having a film thickness in the range of about 5,000 to about 9,000 Angstroms, said noble metal controlling the opacity and operating temperature of said dark field layer.
Claim 2
Dependent Claim
100 words
An electroluminescent display device comprising a transparent electrode layer, a segmented electrode layer, an electroluminescent phosphor layer disposed between said electrode layers, and a dark field layer of a composition of a dielectric material with a noble metal, wherein the percentage of noble metal by volume is in the range of 6%-10%, said dark field layer being interposed between said electroluminescent phosphor layer and said segmented electrode layer, said dark field layer having a film thickness in the range of about 5,000 to about 9,000 Angstroms, said noble metal controlling the opacity and operating temperature of said dark field layer.
Claim 3
Dependent Claim
22 words
An electroluminescent display device as set forth in claim 1 including only a single transparent dielectric layer adjacent the electroluminescent phosphor layer.
Claim 4
Dependent Claim
21 words
An electroluminescent display device as set forth in claim 1 wherein the device has a contrast ratio of at least 2:1.
Claim 5
Dependent Claim
25 words
An electroluminescent display device as set forth in claim 1 wherein the composition of the dark field layer is deposited by co-evaporation from separate sources.
Claim 6
Dependent Claim
16 words
An electroluminescent display device as set forth in claim 1 wherein the noble metal comprises gold.
Claim 7
Dependent Claim
23 words
An electroluminescent display device as set forth in claim 1 wherein said dielectric material of the dark field layer comprises a metal oxide.
Claim 8
Dependent Claim
17 words
An electroluminescent display device as set forth in claim 6 wherein said metal oxide comprises magnesium oxide.
Claim 9
Dependent Claim
22 words
An electroluminescent display device as set forth in claim 1 wherein said dielectric material of the dark field layer comprises silicon dioxide.
Claim 10
Dependent Claim
22 words
An electroluminescent display device as set forth in claim 1 wherein said dielectric material of the dark field layer comprises germanium dioxide.
Claim 11
Dependent Claim
22 words
An electroluminescent display device as set forth in claim 1 wherein said dielectric material of the dark field layer comprises aluminum nitride.
Claim 12
Dependent Claim
26 words
An electroluminescent display device as set forth in claim 1 wherein said dielectric material is comprised of a metal oxide, a metal nitride or a semiconductor.
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) | 1988-10-14 | 1989-04-15 | 1989-10-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-14 | 1993-04-15 | 1993-10-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-14 | 1997-04-15 | 1997-10-15 | $7700.00 | Window Closed / Lapsed |