Patent US5444268A successfully refreshed from Google Patents.
US5444268A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thin film el device
Assignee: Komatsu Ltd
•
Filing: 1990-11-02
•
Granted: 1995-08-22
•
Expires: 2010-11-02
Abstract
Abstract The present invention relates to a modification of a thin film EL device for performing an EL emission according to an electric field being applied, and in particular to a thin film EL device for providing a stable luminance for a long time and for improving the luminance of a blue color display. Therefore, a light emission layer (4) is composed of a sulfide of an alkaline earth metal as a basic material. Insulation layers (3) and (5) disposed adjacent to the light emission layer (4) are composed of a sulfate or a carbonate of an alkaline earth metal. The light emission layer (4) is composed of SrS as a basic material, Ce as a light emission substance, and a Pb dopant as a coactivator.
Inventors
- 👤 Atsushi Miyakoshi
- 👤 Akira Matsuno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:46
CPC Classifications
H; H05; H05B; H05B33/00; H05B33/12; H05B33/18; C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7715; C09K11/7716; C09K11/7718; H05B33/14; H05B33/22
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
106 words
A thin film EL device, comprising: a pair of opposed electrodes; and a laminate composed of a light emission layer and first and second insulation layers with said light emission layer being positioned between said first and second insulation layers, said laminate being positioned between said electrodes with each one of said first and second insulation layers separating a respective one of said electrodes from said light emission layer; wherein said light emission layer is composed of SrS as a light emission substance, Ce as a light emission substance, and Pb as a coactivator, wherein the amount of Pb coactivator does not exceed 1 atomic %.
Claim 2
Dependent Claim
106 words
A thin film EL device, comprising: a pair of opposed electrodes; and a laminate composed of a light emission layer and first and second insulation layers with said light emission layer being positioned between said first and second insulation layers, said laminate being positioned between said electrodes with each one of said first and second insulation layers separating a respective one of said electrodes from said light emission layer; wherein said light emission layer is composed of SrS as a light emission substance, Ce as a light emission substance, and Pb as a coactivator, wherein the amount of Pb coactivator does not exceed 1 atomic %.
Claim 3
Dependent Claim
27 words
A thin film EL device in accordance with claim 1, wherein the level of Pb in the light emission layer is less than about 0.4 atomic %.
Claim 4
Dependent Claim
25 words
A thin film EL device in accordance with claim 2, wherein the level of Ce in the light emission layer is about 0.1 atomic %.
Claim 5
Dependent Claim
25 words
A thin film EL device in accordance with claim 1, wherein the level of Pb in the light emission layer is about 0.3 atomic %.
Claim 6
Dependent Claim
105 words
A thin film EL device, comprising: a pair of opposed electrodes; a laminate composed of a light emission layer sandwiched between first and second insulation layers, said laminate being positioned between said electrodes, each of said electrodes being separated from said light emission layer by one of said first and second insulation layers; wherein said light emission layer comprises a sulfide of an alkaline earth metal; and wherein each of said first and second insulation layers contains a sulfate of an alkaline earth metal which is the same alkaline earth metal as in the sulfide of the alkaline earth metal in said light emission layer.
Claim 7
Dependent Claim
105 words
A thin film EL device, comprising: a pair of opposed electrodes; a laminate composed of a light emission layer sandwiched between first and second insulation layers, said laminate being positioned between said electrodes, each of said electrodes being separated from said light emission layer by one of said first and second insulation layers; wherein said light emission layer comprises a sulfide of an alkaline earth metal; and wherein each of said first and second insulation layers contains a sulfate of an alkaline earth metal which is the same alkaline earth metal as in the sulfide of the alkaline earth metal in said light emission layer.
Claim 8
Dependent Claim
106 words
A thin film EL device, comprising: a pair of opposed electrodes; a laminate composed of a light emission layer sandwiched between first and second insulation layers, said laminate being positioned between Said electrodes, each of said electrodes being separated from said light emission layer by one of said first and second insulation layers; wherein said light emission layer comprises a sulfide of an alkaline earth metal; and wherein each of said first and second insulation layers consists of a carbonate of an alkaline earth metal which is the same alkaline earth metal as in the sulfide of the alkaline earth metal in said light emission layer.
Claim 9
Dependent Claim
106 words
A thin film EL device, comprising: a pair of opposed electrodes; a laminate composed of a light emission layer sandwiched between first and second insulation layers, said laminate being positioned between Said electrodes, each of said electrodes being separated from said light emission layer by one of said first and second insulation layers; wherein said light emission layer comprises a sulfide of an alkaline earth metal; and wherein each of said first and second insulation layers consists of a carbonate of an alkaline earth metal which is the same alkaline earth metal as in the sulfide of the alkaline earth metal in said light emission layer.
Claim 10
Dependent Claim
51 words
A thin film EL device in accordance with claim 6, further comprising: third and fourth insulation layers, said third insulation layer being disposed between one of said electrodes and said first insulation layer, said fourth insulation layer being disposed between the other one of said electrodes and said second insulation layer.
Claim 11
Dependent Claim
37 words
A thin film EL device in accordance with claim 7, wherein each of said third and fourth insulation layers comprises at least one member of the group consisting of Ta 2 O 5 , SION, and SiN:H.
Claim 12
Dependent Claim
98 words
A thin film EL device, comprising: a pair of opposed electrodes; a laminate composed of alight emission layer sandwiched between first and second insulation layers, said laminate being positioned between said electrodes, each of said electrodes being separated from said light emission layer by one of said first and second insulation layers; wherein said light emission layer comprises strontium sulfide and cerium; and wherein each of said first and second insulation layers comprises at least one material selected from the group consisting of a sulfate of an alkaline earth metal and a carbonate of an alkaline earth metal.
Claim 13
Dependent Claim
98 words
A thin film EL device, comprising: a pair of opposed electrodes; a laminate composed of alight emission layer sandwiched between first and second insulation layers, said laminate being positioned between said electrodes, each of said electrodes being separated from said light emission layer by one of said first and second insulation layers; wherein said light emission layer comprises strontium sulfide and cerium; and wherein each of said first and second insulation layers comprises at least one material selected from the group consisting of a sulfate of an alkaline earth metal and a carbonate of an alkaline earth metal.
Claim 14
Dependent Claim
18 words
A thin film EL device in accordance with claim 9, wherein said light emission layer further comprises chlorine.
Claim 15
Dependent Claim
35 words
A thin film EL device in accordance with claim 9, wherein said light emission layer further comprises lead, with the level of lead in the light emission layer being less than about 1 atomic %.
Claim 16
Dependent Claim
35 words
A thin film EL device in accordance with claim 9, wherein said light emission layer further comprises lead, with the level of lead in the light emission layer being less than about 0.4 atomic %.
Claim 17
Dependent Claim
25 words
A thin film EL device in accordance with claim 12, wherein the level of cerium in the light emission layer is about 0.1 atomic %.
Claim 18
Dependent Claim
25 words
A thin film EL device in accordance with claim 12, wherein the level of lead in the light emission layer is about 0.3 atomic %.
Claim 19
Dependent Claim
31 words
A thin film EL device in accordance with claim 5, wherein said light emission layer comprises strontium sulfide, and wherein each of said first and second insulation layers comprises strontium sulfate.
Claim 20
Dependent Claim
18 words
A thin film EL device in accordance with claim 15, wherein said light emission layer further comprises cerium.
Claim 21
Dependent Claim
35 words
A thin film EL device in accordance with claim 16, wherein said light emission layer further comprises lead, with the level of lead in the light emission layer being less than about 1 atomic %.
Claim 22
Dependent Claim
51 words
A thin film EL device in accordance with claim 5, further comprising: third and fourth insulation layers, said third insulation layer being disposed between one of said electrodes and said first insulation layer, said fourth insulation layer being disposed between the other one of said electrodes and said second insulation layer.
Claim 23
Dependent Claim
37 words
A thin film EL device in accordance with claim 18, wherein each of said third and fourth insulation layers comprises at least one member of the group consisting of Ta 2 O 5 , SiON, and SiN:H.
References Cited (Backward Citations)
JPS58125781A
Cited
JPS61121290A
Cited
US4717858A
Cited
JPS625596A
Cited
US4900584A
Cited
US5101288A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-08-21 | 1999-02-20 | 1999-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-08-21 | 2003-02-20 | 2003-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-08-21 | 2007-02-20 | 2007-08-22 | $7700.00 | Window Closed / Lapsed |