US4720436A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electroluminescence devices and method of fabricating the same
Assignee: Ricoh Co Ltd
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Filing: 1986-09-05
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Granted: 1988-01-19
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Expires: 2006-09-05
Abstract
Abstract A thin film electroluminescent device is disclosed which includes an electroluminescent emitting layer comprising an alkaline-earth selenide, such as SrSe (strontium selenide) and calcium selenide (CaSe), or an alkaline-earth sulfide, such as CaS (calcium sulfide) and strontium sulfide (SrS), as the luminescent host material, and a lanthanoid rare-earth element as an activator, and a method of fabricating the same is also disclosed.
Inventors
- 👤 Seiichi Ohseto
- 👤 Yoshiyuki Kageyama
- 👤 Kenji Kameyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:31
CPC Classifications
H; H05; H05B; H05B33/00; H05B33/10; C; C09; C09K; C09K11/00; C09K11/08; C09K11/88; C09K11/881; C09K11/886; C23; C23C; C23C14/00; C23C14/06; C23C14/0623; H05B33/12; H05B33/22; Y; Y10; Y10S; Y10S428/00; Y10S428/917
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
28 words
A thin film electroluminescent device including an electroluminescent emitting layer which comprises a luminescent host material consisting of SrSe or CaSe, and a lanthanoid rare-earth element as activator.
Claim 2
Dependent Claim
28 words
A thin film electroluminescent device including an electroluminescent emitting layer which comprises a luminescent host material consisting of SrSe or CaSe, and a lanthanoid rare-earth element as activator.
Claim 3
Dependent Claim
26 words
The thin film electroluminescent device as claimed in claim 1, wherein said lanthanoid rare-earth element is selected from the group consisting of Ce, Eu and Tb.
Claim 4
Dependent Claim
60 words
A thin film electroluminescent device comprising: a substrate, a transparent electrode layer formed on said substrate, an electroluminescent emitting layer comprising a luminescent host material consisting of SrSe or CaSe, and a lanthanoid rare-earth element as activator, formed on said transparent electrode layer, an insulating layer formed on said electroluminescent emitting layer, and an electrode formed on said insulating layer.
Claim 5
Dependent Claim
60 words
A thin film electroluminescent device comprising: a substrate, a transparent electrode layer formed on said substrate, an electroluminescent emitting layer comprising a luminescent host material consisting of SrSe or CaSe, and a lanthanoid rare-earth element as activator, formed on said transparent electrode layer, an insulating layer formed on said electroluminescent emitting layer, and an electrode formed on said insulating layer.
Claim 6
Dependent Claim
37 words
The thin film electroluminescent device as claimed in claim 3, wherein another insulating layer which may be identical with or different from said insulating layer is interposed between said transparent electrode layer and said electroluminescent emitting layer.
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) | 1991-01-18 | 1991-07-20 | 1992-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-18 | 1995-07-20 | 1996-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-18 | 1999-07-20 | 2000-01-19 | $7700.00 | Window Closed / Lapsed |