US4792728A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cathodoluminescent garnet lamp
Assignee: International Business Machines Corp
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Filing: 1985-06-10
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Granted: 1988-12-20
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Expires: 2005-06-10
Abstract
Abstract A cathodoluminescent lamp in the form of a vacuum diode or triode uses a self-supporting YAG crystal as the light emitter. The crystal shape can be selected (spherical, slab, bar) for desired effect and light trapping is turned to advantage by selectively coating the crystal surface to provide for preferential light emission.
Inventors
- 👤 Ifay F. Chang
- 👤 Ronald I. Feigenblatt
- 👤 Webster E. Howard
- 👤 Eugene I. Gordon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:02
CPC Classifications
H; H01; H01J; H01J63/00
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
95 words
An intense light source comprising a coating means to inhibit light transmission from regions of said crystal: an evacuated chamber formed by one or more walls, a self-supporting garnet crystal in said evacuated chamber, a relatively massive heat sink in heat conducting relation to said crystal, excitation means located in said chamber for exciting said garnet crystal simultaneously over a substantial portion of a surface of said crystal, with electromagnetic radiation from many directions, and a light transmitting region in at least one wall of said chamber for transmitting light emitted by said garnet crystal.
Claim 2
Dependent Claim
95 words
An intense light source comprising a coating means to inhibit light transmission from regions of said crystal: an evacuated chamber formed by one or more walls, a self-supporting garnet crystal in said evacuated chamber, a relatively massive heat sink in heat conducting relation to said crystal, excitation means located in said chamber for exciting said garnet crystal simultaneously over a substantial portion of a surface of said crystal, with electromagnetic radiation from many directions, and a light transmitting region in at least one wall of said chamber for transmitting light emitted by said garnet crystal.
Claim 3
Dependent Claim
11 words
The source of claim 1 in which said crystal is spherical.
Claim 4
Dependent Claim
11 words
The source of claim 1 in which said crystal is prismatic.
Claim 5
Dependent Claim
13 words
The source of claim 1 in which said crystal is a circular disc.
Claim 6
Dependent Claim
15 words
The source of claim 1 in which said crystal is a slab of rectangular cross-section.
Claim 7
Dependent Claim
15 words
The source of claim 1 in which said crystal is a rod of rectangular cross-section.
Claim 8
Dependent Claim
11 words
The source of claim 1 in which said crystal is YAG.
Claim 9
Dependent Claim
12 words
The source of claim 7 in which said crystal is cerium doped.
Claim 10
Dependent Claim
18 words
The source of claim 1 which includes a potential source coupled to said crystal via said heat sink.
Claim 11
Dependent Claim
43 words
The source of claim 1 in which said excitation means comprises: a heated conductor located adjacent said crystal, a potential source for providing a potential difference between said crystal and said conductor whereby said crystal is bombarded with electrons emitted by said conductor.
Claim 12
Dependent Claim
12 words
The source of claim 10 in which said conductor is indirectly heated.
Claim 13
Dependent Claim
12 words
The source of claim 10 in which said conductor is directly heated.
Claim 14
Dependent Claim
17 words
The source of claim 1 in which said walls include a region with a condensing lens property.
Claim 15
Dependent Claim
20 words
The source of claim 1 in which at least a portion of said walls are coated to inhibit light transmission.
Claim 16
Dependent Claim
14 words
The source of claim 10 wherein said potential source is an alternating current source.
Claim 17
Dependent Claim
14 words
The source of claim 10 wherein said potential source is a direct current source.
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) | 1991-12-20 | 1992-06-20 | 1992-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-12-20 | 1996-06-20 | 1996-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-12-20 | 2000-06-20 | 2000-12-20 | $7700.00 | Window Closed / Lapsed |