US4916360A
Expired / Lapsed
US
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Thin film electroluminescent device with ZnS as host material
Assignee: Sharp Corp
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Filing: 1988-07-07
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Granted: 1990-04-10
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Expires: 2008-07-07
Abstract
Abstract A thin film electroluminescent (EL) device which emits a luminescence in response to the application of an electric field, and comprises ZnS as a host material and a rare earth element providing luminescent centers.
Inventors
- 👤 Akiyoshi Mikami
- 👤 Takashi Ogura
- 👤 Kouji Taniguchi
- 👤 Masaru Yoshida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:14
CPC Classifications
H; H05; H05B; H05B33/00; H05B33/12; H05B33/14; H05B33/145; Y; Y10; Y10S; Y10S428/00; Y10S428/917
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
69 words
A thin film EL device which comprises an EL film made of ZnS serving as its host material and doped with a rare earth element to provide luminescent centers, the EL film having a ratio of S atoms to Zn atoms (S/Zn) in the controlled range of 1.02≦S/Zn≦1.13, insulating layers sandwiching the EL film and a pair of electrodes provided on the respective outer surfaces of the insulating layers.
Claim 2
Dependent Claim
69 words
A thin film EL device which comprises an EL film made of ZnS serving as its host material and doped with a rare earth element to provide luminescent centers, the EL film having a ratio of S atoms to Zn atoms (S/Zn) in the controlled range of 1.02≦S/Zn≦1.13, insulating layers sandwiching the EL film and a pair of electrodes provided on the respective outer surfaces of the insulating layers.
Claim 3
Dependent Claim
27 words
The EL device of claim 1 in which the rare earth element is selected from the group of those having an atomic number of 59 to 69.
Claim 4
Dependent Claim
25 words
The EL device of claim 1 in which the rare earth element is selected from the group consisting of Tb, Sm, Tm, Eu and Pr.
Claim 5
Dependent Claim
25 words
The EL device of claim 1 in which the concentration of the rare earth element in the EL film is 0.5 to 3 at. %.
Claim 6
Dependent Claim
18 words
The EL device of claim 1 in which the EL film is 0.3 to 1.5 μm in thickness.
Claim 7
Dependent Claim
30 words
The EL device of claim 1 in which the EL film is prepared by a sputtering or vacuum evaporation method using ZnS and a sulfide of the rare earth element.
Claim 8
Dependent Claim
25 words
The EL device of claim 6 in which the rare earth element is selected from the group consisting of Tb, Sm, Tm, Eu and Pr.
Claim 9
Dependent Claim
25 words
The EL device of claim 3 in which the concentration of the rare earth element in the EL film is 0.5 to 3 at. %.
Claim 10
Dependent Claim
30 words
The EL device of claim 8 in which the EL film is prepared by a sputtering or vacuum evaporation method using ZnS and a sulfide of the rare earth element.
Claim 11
Dependent Claim
18 words
The EL device of claim 9 in which the EL film is 0.3 to 1.5 μm in thickness.
Claim 12
Dependent Claim
88 words
A thin film EL device which consists essentially of an EL film made of ZnS serving as its host material and doped with a rare earth element to provide luminescent centers, the EL film having a ratio of S atoms to Zn atoms (S/Zn) in the controlled range of 1.02≦S/Zn≦1.13, insulating layers sandwiching the EL film and a pair of electrodes provided on the respective outer surfaces of the insulating layers, wherein the EL film is prepared by using ZnS and a sulfide of the rare earth element.
Claim 13
Dependent Claim
88 words
A thin film EL device which consists essentially of an EL film made of ZnS serving as its host material and doped with a rare earth element to provide luminescent centers, the EL film having a ratio of S atoms to Zn atoms (S/Zn) in the controlled range of 1.02≦S/Zn≦1.13, insulating layers sandwiching the EL film and a pair of electrodes provided on the respective outer surfaces of the insulating layers, wherein the EL film is prepared by using ZnS and a sulfide of the rare earth element.
Claim 14
Dependent Claim
27 words
The EL device of claim 1 in which the rare earth element is selected from the group of those having an atomic number of 59 to 69.
Claim 15
Dependent Claim
25 words
The EL device of claim 11 in which the rare earth element is selected from the group consisting of Tb, Sm, Tm, Eu and Pr.
Claim 16
Dependent Claim
25 words
The EL device of claim 11 in which the concentration of the rare earth element in the EL film is 0.5 to 3 at. %.
Claim 17
Dependent Claim
18 words
The EL device of claim 11 in which the EL film is 0.3 to 1.5 μm in thickness.
References Cited (Backward Citations)
US4707419A
Cited
US4758765A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-04-09 | 1993-10-09 | 1994-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-09 | 1997-10-09 | 1998-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-09 | 2001-10-09 | 2002-04-10 | $7700.00 | Window Closed / Lapsed |