US4975338A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thin film electroluminescence device
Assignee: Ricoh Co Ltd
•
Filing: 1989-04-12
•
Granted: 1990-12-04
•
Expires: 2009-04-12
Abstract
Abstract A thin film EL device is disclosed which comprises (a) a substrate, (b) a transparent electrode layer formed on the substrate, (c) one or more insulating layers formed on the transparent electrode layer, with at least one of the insulating layers comprising a crystalline nitride, (d) an electroluminescent emitting layer comprising a luminescent host material consisting of an alkali earth calcogen compound formed on the insulating layers, and (e) a back electrode layer. In the above thin film EL device, it is preferable that the insulating layer in contact with the electroluminescent layer comprise a crystalline aluminum nitride or boron nitride, and that the transparent electrode layer comprise a host material consisting of a C-axis oriented zinc oxide.
Inventors
- 👤 Yoshiyuki Kageyama
- 👤 Seiichi Ohseto
- 👤 Kenji Kameyama
- 👤 Hiroshi Deguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 14:19
CPC Classifications
H; H05; H05B; H05B33/00; H05B33/12; H05B33/14; H05B33/145; H05B33/18; H05B33/22; H05B33/26; H05B33/28
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
125 words
A thin film electroluminescence device comprising: a substrate, a transparent electrode layer formed on said substrate, an insulating layer consisting of one or more constituent layers formed on said transparent electrode layer, at least one of said constituent insulating layers comprising a crystalline aluminum nitride or boron nitride wherein the crystallinity of said crystalline nitride is 1 or more when indicated by a reciprocal number of the half width of the X-ray diffraction pattern, an electroluminescence emitting layer comprising an electroluminescence host material and an activator, formed on said constituent insulating layer comprising a crystalline nitride, said electroluminescence host material being an alkali earth chalcogen compound, and said activator being a rare earth element, and a transparent back electrode layer formed on said electroluminescence layer.
Claim 2
Dependent Claim
125 words
A thin film electroluminescence device comprising: a substrate, a transparent electrode layer formed on said substrate, an insulating layer consisting of one or more constituent layers formed on said transparent electrode layer, at least one of said constituent insulating layers comprising a crystalline aluminum nitride or boron nitride wherein the crystallinity of said crystalline nitride is 1 or more when indicated by a reciprocal number of the half width of the X-ray diffraction pattern, an electroluminescence emitting layer comprising an electroluminescence host material and an activator, formed on said constituent insulating layer comprising a crystalline nitride, said electroluminescence host material being an alkali earth chalcogen compound, and said activator being a rare earth element, and a transparent back electrode layer formed on said electroluminescence layer.
Claim 3
Dependent Claim
54 words
The thin film electroluminescence device as claimed in claim 1, further comprising a second insulating layer comprising one or more constituent layers between said electroluminescence emitting layer and said transparent back electrode layer, at least one of said constituent insulating layers comprising a crystalline nitride and being in contact with said electroluminescence emitting layer.
Claim 4
Dependent Claim
29 words
The thin film electroluminescence device as claimed in claim 2, wherein the thickness of said second insulating layer is in the range of from 1,000 Å to 2 μm.
Claim 5
Dependent Claim
53 words
The thin film electroluminescence device as claimed in claim 2, wherein said constituent insulating layer other than said constituent layer comprising a crystalline nitride comprises a dielectric compound selected from the group consisting of SiO 2 , Al 2 O 3 , Ta 2 O 5 , SrTiO 3 and PbTiO 3 .
Claim 6
Dependent Claim
32 words
The thin film electroluminescence device as claimed in claim 4, wherein the thickness of said constituent layer comprising said dielectric compound is in the range of from 500 Å to 3,000 Å.
Claim 7
Dependent Claim
26 words
The thin film electroluminescence device as claimed in claim 1, wherein said transparent back electrode layer comprises a C-axis oriented zinc oxide as a host material.
Claim 8
Dependent Claim
19 words
The thin film electroluminescence device as claimed in claim 1, wherein said crystalline nitride is a crystalline aluminum nitride.
Claim 9
Dependent Claim
19 words
The thin film electroluminescence device as claimed in claim 1, wherein said crystalline nitride is a crystalline boron nitride.
Claim 10
Dependent Claim
32 words
The thin film electroluminescence device as claimed in claim 1, wherein said alkali earth chalcogen compound is an alkali earth metal sulfide selected from the group consisting of SrS, CaS and BaS.
Claim 11
Dependent Claim
32 words
The thin film electroluminescence device as claimed in claim 1, wherein said alkali earth chalcogen compound is an alkali earth metal selenide selected from the group consisting of SrSe, CaSe and BaSe.
Claim 12
Dependent Claim
29 words
The thin film electroluminescence device as claimed in claim 1, wherein said rare earth element is selected from the group consisting of Ce, Pr, Sm, Eu, Tb and Tm.
Claim 13
Dependent Claim
33 words
The thin film electroluminescence device as claimed in claim 1, wherein said substrate is made of a material selected from the group consisting of soda-lime glass, borosilicate glass, aluminosilicate glass and quartz glass.
Claim 14
Dependent Claim
37 words
The thin film electroluminescence device as claimed in claim 1, wherein said transparent electrode layer is made of a material selected from the group consisting of Al, ITO, Sb-doped SnO 2 , Al-doped ZnO, and Si-doped ZnO.
Claim 15
Dependent Claim
25 words
The thin film electroluminescence device as claimed in claim 11, wherein said Al-doped ZnO and said Si-doped ZnO are of a C-axis oriented crystalline type.
Claim 16
Dependent Claim
29 words
The thin film electroluminescence device as claimed in claim 1, wherein the thickness of said transparent electrode layer is in the range of from 1,000 Å to 5,000 Å.
Claim 17
Dependent Claim
28 words
The thin film electroluminescence device as claimed in claim 1, wherein the thickness of said insulating layer is in the range of from 1,000 Å to 2 μm.
Claim 18
Dependent Claim
53 words
The thin film electroluminescence device as claimed in claim 1, wherein said constituent insulating layer other than said constituent layer comprising a crystalline nitride comprises a dielectric compound selected from the group consisting of SiO 2 , Al 2 O 3 , Ta 2 O 5 , SrTiO 3 and PbTiO 3 .
Claim 19
Dependent Claim
32 words
The thin film electroluminescence device as claimed in claim 17, wherein the thickness of said constituent layer comprising said dielectric compound is in the range of from 500 Å to 3,000 Å.
Claim 20
Dependent Claim
29 words
The thin film electroluminescence device as claimed in claim 1, wherein the thickness of said electroluminescence emitting layer is in the range of from 5,000 Å to 15,000 Å.
Claim 21
Dependent Claim
37 words
The thin film electroluminescence device as claimed in claim 1, wherein said back electrode layer is made of a material selected from the group consisting of Al, ITO, Sb-doped SnO 2 , Al-doped ZnO and Si-deoped ZnO.
Claim 22
Dependent Claim
29 words
The thin film electroluminescence device as claimed in claim 1, wherein the thickness of said back electrode layer is in the range of from 1,000 Å to 10,000 Å.
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) | 1993-12-03 | 1994-06-04 | 1994-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-03 | 1998-06-04 | 1998-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-03 | 2002-06-04 | 2002-12-04 | $7700.00 | Window Closed / Lapsed |