US3706885A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photocathode-phosphor imaging system for x-ray camera tubes
Assignee: General Electric Co
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Filing: 1971-01-29
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Granted: 1972-12-19
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Expires: 1991-01-29
Abstract
Abstract An improved system for emission of electrons in response to xrays comprises a phosphor layer separated from a photocathode layer by a light transparent barrier layer which protects the phosphors and the binders in the phosphor layer from attack by the chemicals in the photocathode layer. The system is useful in various types of camera tubes including image orthicons and intensifier vidicons as well as direct view tubes to convert a light image of X-rays into a corresponding electron emission pattern.
Inventors
- 👤 Karoly G Fister
- 👤 Martin D Gibbons
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:03
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/02; H01J29/10; H01J29/36; H01J29/38; H01J29/385; G; G21; G21K; G21K4/00
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
15 words
The device of claim 1 where said phosphor layer is carried on a glass substrate.
Claim 2
Dependent Claim
112 words
The process of forming a device capable of emitting electrons in response to light energy of X-ray wavelength imaged thereon comprising: a. forming a first phosphor layer comprising phosphors capable of emitting visible light in response to X-ray stimulation and bonded in a silicon resin binder; b. forming a barrier layer on said phosphor layer comprising a 200- 10,000 angstrom layer of visible light transparent material consisting essentially of an alkali metal aluminum fluoride capable of providing resistance to chemical attack on said binder and said phosphors by alkali metal; and c. forming a photocathode layer on said barrier layer comprising at least one alkali metal in combination with a second metal.
Claim 3
Independent Claim
109 words
A device capable of emitting a pattern of electrons from an alkali metal photocathode layer in response to light energy of X-ray wavelengths imaged on an adjacent phosphor layer comprising: a. a phosphor layer comprising phosphors capable of emitting visible light in response to X-ray stimulation and a silicon resin binder; b. a protective, visible light transparent, layer of sodium aluminum fluoride of about 200- 10,000 angstrom thickness on said phosphor layer to protect said phosphors and said silicon resin binder from chemical attack by said alkali metal; and c. a photocathode layer on said protective layer comprising at least one alkali metal in combination with a second metal.
References Cited (Backward Citations)
US2798823A
Cited
US3436550A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-12-19 | 1976-06-19 | 1976-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-19 | 1980-06-19 | 1980-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-19 | 1984-06-19 | 1984-12-19 | $7700.00 | Window Closed / Lapsed |