Patent US5200277A successfully refreshed from Google Patents.
US5200277A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electroluminescent device
Assignee: Hitachi Ltd
•
Filing: 1989-12-22
•
Granted: 1993-04-06
•
Expires: 2009-12-22
Abstract
Abstract An electroluminescent device including dielectric films each of which consists of first regions made of a material with a strong self-healing type dielectric breakdown characteristic, second regions made of a material with a strong propagating type dielectric breakdown characteristic, and mixed regions consisting of a mixture of these two materials, the first and second regions being arranged alternately in the film thickness direction with the mixed regions therebetween, the mixing ratio of these two materials in the mixed regions changing in such a manner that the ratio of one material gradually decreases from a region of this material toward the adjacent region of the other material, that is, the ratio of the other material increases. Thus, the changes in the mixing ratio of these two materials of the dielectric films in the film thickness direction are continuous and periodic. These dielectric films, with a high breakdown field strength, make it possible to obtain an electroluminescent device having a large drive voltage margin and providing a luminescence of high brightness.
Inventors
- 👤 Takahiro Nakayama
- 👤 Kenichi Onisawa
- 👤 Katsumi Tamura
- 👤 Kazuo Taguchi
- 👤 Akira Sato
- 👤 Kenichi Hashimoto
- 👤 Yoshio Abe
- 👤 Masanobu Hanazono
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:55
CPC Classifications
H; H05; H05B; H05B33/00; H05B33/12; H05B33/22; C; C23; C23C; C23C14/00; C23C14/06; C23C14/08; H05B33/10; Y; Y10; Y10S; Y10S428/00; Y10S428/917; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/24975; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
174 words
An electroluminescent device comprising: a substrate: first electrodes formed on said substrate; a first dielectric film formed on said first electrodes; an active layer formed on said first dielectric film; a second dielectric film formed on said active layer; and second electrodes formed on said second dielectric film; said first and second dielectric films including first regions made of a material with a strong self-healing type dielectric breakdown characteristic, second regions made of a material with a strong propagating type dielectric breakdown characteristic, and mixed region consisting of a mixture of these two materials, said first and second regions being arranged alternately in the film thickness direction with said mixed regions therebetween, the mixing ratio of these two materials in said mixed regions changing in such a manner that the ratio of one material gradually decreases from a region of this material toward the adjacent region of the other material, the changes in the mixing ratio of these two materials of the dielectric films in the film thickness direction being thus continuous and periodic.
Claim 2
Dependent Claim
174 words
An electroluminescent device comprising: a substrate: first electrodes formed on said substrate; a first dielectric film formed on said first electrodes; an active layer formed on said first dielectric film; a second dielectric film formed on said active layer; and second electrodes formed on said second dielectric film; said first and second dielectric films including first regions made of a material with a strong self-healing type dielectric breakdown characteristic, second regions made of a material with a strong propagating type dielectric breakdown characteristic, and mixed region consisting of a mixture of these two materials, said first and second regions being arranged alternately in the film thickness direction with said mixed regions therebetween, the mixing ratio of these two materials in said mixed regions changing in such a manner that the ratio of one material gradually decreases from a region of this material toward the adjacent region of the other material, the changes in the mixing ratio of these two materials of the dielectric films in the film thickness direction being thus continuous and periodic.
Claim 3
Dependent Claim
38 words
An electroluminescent device according to claim 1, wherein said material with a strong self-healing type breakdown characteristic is one selected from the group consisting of SiO 2 , Si 3 N 4 and Ta 2 O 5 .
Claim 4
Dependent Claim
78 words
An electroluminescent device according to claim 2, wherein said material with a strong propagating type dielectric breakdown characteristic is one selected from the group consisting of Y 2 O 3 , Sm 2 O 3 , TiO 2 , HfO 2 , Al 2 O 3 , ZrO 2 , X-TaO 3 , X-NbO 3 and X-TiO 3 , where X represents a metal selected from the group consisting of Sr, Ba, Pb, Sn, Mg, Zn and Cd.
Claim 5
Dependent Claim
41 words
An electroluminescent device according to claim 1, wherein the deposition period in the film thickness direction of said regions made of any one of the two materials forming said dielectric films being in the range of 0.5 nm to 30 nm.
Claim 6
Independent Claim
189 words
A method of manufacturing electroluminescent devices, comprising the steps of: forming first electrodes on a substrate; forming a first dielectric film by depositing alternately on said first electrodes first regions made of a material with a strong self-healing type dielectric breakdown characteristic and second regions made of a material with a strong propagating type dielectric breakdown characteristic, some of the particles of one material in one of the first and second regions sinking into an adjacent, previously formed region, which is made of the other material to provide a mixed region therebetween, the mixing ratio of these two materials in said mixed regions changing in such a manner that the ratio of one material gradually decreases from a region of this material toward the adjacent region of the other material, the changes in the mixing ratio of these two materials of the dielectric films in the film thickness direction being thus continuous and periodic; forming an active layer on said dielectric film; forming a second dielectric film in the same manner as in the case of said first dielectric film; and forming second electrodes on said second dielectric film.
Claim 7
Independent Claim
189 words
A method of manufacturing electroluminescent devices, comprising the steps of: forming first electrodes on a substrate; forming a first dielectric film by depositing alternately on said first electrodes first regions made of a material with a strong self-healing type dielectric breakdown characteristic and second regions made of a material with a strong propagating type dielectric breakdown characteristic, some of the particles of one material in one of the first and second regions sinking into an adjacent, previously formed region, which is made of the other material to provide a mixed region therebetween, the mixing ratio of these two materials in said mixed regions changing in such a manner that the ratio of one material gradually decreases from a region of this material toward the adjacent region of the other material, the changes in the mixing ratio of these two materials of the dielectric films in the film thickness direction being thus continuous and periodic; forming an active layer on said dielectric film; forming a second dielectric film in the same manner as in the case of said first dielectric film; and forming second electrodes on said second dielectric film.
Claim 8
Dependent Claim
19 words
A method according to claim 5, wherein radio-frequency sputtering is applied for the steps of forming said dielectric films.
Claim 9
Dependent Claim
19 words
A method according to claim 5, wherein vacuum evaporation is applied for the steps of forming said dielectric films.
Claim 10
Dependent Claim
20 words
A method according to claim 5, wherein molecular beam epitaxy is applied for the steps of forming said dielectric films.
Claim 11
Dependent Claim
20 words
A method according to claim 5, wherein chemical vapor deposition is applied for the steps of forming said dielectric films.
Claim 12
Dependent Claim
213 words
An electroluminescent device comprising: a transparent, electrically insulating substrate; first electrodes formed on said substrate; a first transparent dielectric film formed on said first electrodes; an active layer formed on said first transparent dielectric film and adapted to generate electroluminescence when voltage is applied thereto; a second transparent dielectric film formed on said active layer, and second electrodes formed on said second transparent dielectric film; voltage being applied to said active layer from said first and second electrodes arranged face to face with each other, at least one of said first and second electrodes being transparent, said first and second dielectric films being formed by alternately arranging in the film thickness direction regions containing SiO 2 and having a thickness of about 3 nm and regions containing TiO 2 and having a thickness of about 1 nm, with mixed regions consisting of a mixture of SiO 2 and TiO 2 and having a thickness of about 1 nm being arranged therebetween, the mixing ratio of SiO 2 and TiO 2 of said mixed regions being such that TiO 2 increases from a SiO 2 region toward a TiO 2 region, the changes in the film thickness direction of the mixing ratio of these materials in said dielectric films being thus continuous and periodic.
Claim 13
Dependent Claim
213 words
An electroluminescent device comprising: a transparent, electrically insulating substrate; first electrodes formed on said substrate; a first transparent dielectric film formed on said first electrodes; an active layer formed on said first transparent dielectric film and adapted to generate electroluminescence when voltage is applied thereto; a second transparent dielectric film formed on said active layer, and second electrodes formed on said second transparent dielectric film; voltage being applied to said active layer from said first and second electrodes arranged face to face with each other, at least one of said first and second electrodes being transparent, said first and second dielectric films being formed by alternately arranging in the film thickness direction regions containing SiO 2 and having a thickness of about 3 nm and regions containing TiO 2 and having a thickness of about 1 nm, with mixed regions consisting of a mixture of SiO 2 and TiO 2 and having a thickness of about 1 nm being arranged therebetween, the mixing ratio of SiO 2 and TiO 2 of said mixed regions being such that TiO 2 increases from a SiO 2 region toward a TiO 2 region, the changes in the film thickness direction of the mixing ratio of these materials in said dielectric films being thus continuous and periodic.
Claim 14
Independent Claim
182 words
A method of manufacturing electroluminescent devices, comprising the steps of: forming first electrodes on a substrate; alternately providing on an above said first electrodes SiO 2 and TiO 2 regions by radio-frequency sputtering at deposition rates of 5.5 nm/min and 1.1 nm/min respectively, some of the particles of one material in one of the SiO 2 and TiO 2 regions sinking into an adjacent region of the other material formed previously to provide a mixed region therebetween, the mixing ratio of these two materials in said mixed regions changing in such a manner that the ratio of one material gradually decreases from a region of this material towards the adjacent region of the other material, the changes in the mixing ratio of these two materials of the dielectric films in the film thickness direction being thus continuous and periodic, thus forming a first dielectric film; providing an active layer on said first dielectric film forming a second dielectric film on said active layer in the same manner as informing said first dielectric film; and forming second electrodes on said second dielectric film.
Claim 15
Independent Claim
182 words
A method of manufacturing electroluminescent devices, comprising the steps of: forming first electrodes on a substrate; alternately providing on an above said first electrodes SiO 2 and TiO 2 regions by radio-frequency sputtering at deposition rates of 5.5 nm/min and 1.1 nm/min respectively, some of the particles of one material in one of the SiO 2 and TiO 2 regions sinking into an adjacent region of the other material formed previously to provide a mixed region therebetween, the mixing ratio of these two materials in said mixed regions changing in such a manner that the ratio of one material gradually decreases from a region of this material towards the adjacent region of the other material, the changes in the mixing ratio of these two materials of the dielectric films in the film thickness direction being thus continuous and periodic, thus forming a first dielectric film; providing an active layer on said first dielectric film forming a second dielectric film on said active layer in the same manner as informing said first dielectric film; and forming second electrodes on said second dielectric film.
References Cited (Backward Citations)
US4670355A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-04-05 | 1996-10-05 | 1997-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-04-05 | 2000-10-05 | 2001-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-04-05 | 2004-10-05 | 2005-04-06 | $7700.00 | Window Closed / Lapsed |