US4482841A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composite dielectrics for low voltage electroluminescent displays
Assignee: Texas Instruments Inc
•
Filing: 1982-03-02
•
Granted: 1984-11-13
•
Expires: 2002-03-02
Abstract
Abstract The dielectric, which is provided on either side of the active phosphor in an AC-driven electroluminescent display, is formed of a composite material which has both high dielectric constant and high resistivity. Preferably, a composite of titanum dioxide and alumina is used.
Inventors
- 👤 Shiban K. Tiku
- 👤 Milo R. Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:16
CPC Classifications
H; H05; H05B; H05B33/00; H05B33/12; H05B33/22
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
121 words
A thin film electroluminescent display, comprising: an active phosphor layer; first and second dielectric layers, adjacent to said phosphor layer and on opposite sides thereof; first and second conductor layers respectively adjacent to said first and second dielectric layers and not in contact with said phosphor layer; a substrate adjacent to said first conductor layer; and an encapsulation layer adjacent to said second conductor layer; wherein at least one of said dielectric layers consists essentially of a uniform mixture of a first dielectric material and a second dielectric material, said first dielectric material having a dielectric constant which is more than twice the dielectric constant of said phosphor, and said second dielectric material having a dielectric loss less than said phosphor.
Claim 2
Dependent Claim
121 words
A thin film electroluminescent display, comprising: an active phosphor layer; first and second dielectric layers, adjacent to said phosphor layer and on opposite sides thereof; first and second conductor layers respectively adjacent to said first and second dielectric layers and not in contact with said phosphor layer; a substrate adjacent to said first conductor layer; and an encapsulation layer adjacent to said second conductor layer; wherein at least one of said dielectric layers consists essentially of a uniform mixture of a first dielectric material and a second dielectric material, said first dielectric material having a dielectric constant which is more than twice the dielectric constant of said phosphor, and said second dielectric material having a dielectric loss less than said phosphor.
Claim 3
Dependent Claim
14 words
The display of claim 1, wherein said second dielectric material also has good transparency.
Claim 4
Dependent Claim
24 words
The display of claim 1, wherein said first dielectric material is selected from the group consisting of titanium oxide, zirconium oxide, and hafnium oxide.
Claim 5
Dependent Claim
24 words
The display of claim 1, wherein said second dielectric material is selected from the group consisting of aluminum oxide, scandium oxide, and yttrium oxide.
Claim 6
Dependent Claim
24 words
The display of claim 1, 3, or 4, wherein the fraction of said first dielectric material in said mixture is between 1% and 49%.
Claim 7
Dependent Claim
13 words
The display of claim 5, wherein said first dielectric material is titanium dioxide.
Claim 8
Dependent Claim
12 words
The display of claim 4, wherein said second dielectric material comprises alumina.
Claim 9
Dependent Claim
13 words
The display of claim 7, wherein said first dielectric material comprises titanium dioxide.
Claim 10
Dependent Claim
14 words
The display of claim 7, wherein said uniform mixture comprises approximately 80% of alumina.
Claim 11
Dependent Claim
22 words
The display of claim 1, wherein said phosphor comprises ZnS, and said composite dielectric material has a dielectric constant of approximately 20.
Claim 12
Dependent Claim
15 words
The display of claim 1, wherein one of said conductor layers comprises indium tin oxide.
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) | 1987-11-13 | 1988-05-14 | 1988-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-11-13 | 1992-05-14 | 1992-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-11-13 | 1996-05-14 | 1996-11-13 | $7700.00 | Window Closed / Lapsed |