US4833507A
Expired / Lapsed
US
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Electron emission device
Assignee: Canon Inc
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Filing: 1988-04-11
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Granted: 1989-05-23
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Expires: 2008-04-11
Abstract
Abstract An electron emission device comprises a P-type semiconductor layer which emits electron injected into the P-type semiconductor layer by utilizing the negative electron affinity state. At least one of said N-type semiconductor layer and the P-type semiconductor layer is made to have a super-lattice structure.
Inventors
- 👤 Akira Shimizu
- 👤 Takeo Tsukamoto
- 👤 Akira Suzuki
- 👤 Masao Sugata
- 👤 Isamu Shimoda
- 👤 Masahiko Okunuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:28
CPC Classifications
H; H01; H01J; H01J1/00; H01J1/02; H01J1/30; H01J1/308
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
54 words
An electron emission device comprising a P-type semiconductor layer formed on a N-type semiconductor layer which emits electrons injected into said P-type semiconductor layer by utilizing the negative electron affinity state, characterized in that at least one of said N-type semiconductor layer and said P-type semiconductor layer is made to have a super-lattice structure.
Claim 2
Dependent Claim
54 words
An electron emission device comprising a P-type semiconductor layer formed on a N-type semiconductor layer which emits electrons injected into said P-type semiconductor layer by utilizing the negative electron affinity state, characterized in that at least one of said N-type semiconductor layer and said P-type semiconductor layer is made to have a super-lattice structure.
Claim 3
Dependent Claim
32 words
An electron emission device according to claim 1, wherein at least said N-type semiconductor is made to have a super-lattice structure and at least a part thereof is formed by selective doping.
References Cited (Backward Citations)
US4163237A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-05-22 | 1992-11-21 | 1993-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-22 | 1996-11-21 | 1997-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-22 | 2000-11-21 | 2001-05-23 | $7700.00 | Window Closed / Lapsed |