US3961182A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pick up screens for X-ray image intensifier tubes employing evaporated activated scintillator layer
Assignee: Varian Medical Systems Inc
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Filing: 1972-08-18
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Granted: 1976-06-01
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Expires: 1992-08-18
Abstract
Abstract The present invention relates in general to methods for making pick-up screens for X-ray image intensifier tubes and, more particularly, to an improved method wherein the X-ray fluorescent phosphor screen element is formed by evaporation of an alkali metal halide material in vacuum and condensing the evaporated material on an X-ray transparent portion of the X-ray intensifier tube, whereby a curved X-ray image pick-up screen is formed which has improved quantum efficiency and resolution. Such improved X-ray image intensifier tubes are especially useful for, but not limited in use to, X-ray systems and for intensifying gamma ray images obtained in applications of nuclear medicine.
Inventors
- 👤 William E. Spicer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:09
CPC Classifications
G; G21; G21K; G21K4/00; H; H01; H01J; H01J29/00; H01J29/02; H01J29/10; H01J29/36; H01J29/38; H01J29/385; H01J31/00; H01J31/08; H01J31/50; H01J31/501
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
143 words
An evacuated x-ray image intensifier tube of improved conversion efficiency and resolution comprising: evacuated envelope means; an x-ray pick-up screen disposed within said evacuated envelope means for receiving an x-ray image and converting said x-ray image by scintillation into an optical photon image corresponding to the received x-ray image, said x-ray pick-up screen comprising a vacuum vapor deposited polycrystalline layer of alkali metal halide scintillator material, said scintillator material including an activator so as to be x-ray sensitive and selected from the group consisting of CsI, NaI, LiI, KI, CsBr, and RbI, having a density of alkali metal halide material approximately equal to that of the bulk alkali halide material, and having a thickness greater than 0.0005 inch; and a photocathode layer behind said x-ray pick-up screen for converting said photon image to a corresponding electron image for emission into said evacuated envelope.
Claim 2
Dependent Claim
143 words
An evacuated x-ray image intensifier tube of improved conversion efficiency and resolution comprising: evacuated envelope means; an x-ray pick-up screen disposed within said evacuated envelope means for receiving an x-ray image and converting said x-ray image by scintillation into an optical photon image corresponding to the received x-ray image, said x-ray pick-up screen comprising a vacuum vapor deposited polycrystalline layer of alkali metal halide scintillator material, said scintillator material including an activator so as to be x-ray sensitive and selected from the group consisting of CsI, NaI, LiI, KI, CsBr, and RbI, having a density of alkali metal halide material approximately equal to that of the bulk alkali halide material, and having a thickness greater than 0.0005 inch; and a photocathode layer behind said x-ray pick-up screen for converting said photon image to a corresponding electron image for emission into said evacuated envelope.
Claim 3
Dependent Claim
37 words
The x-ray image intensifier tube of claim 1 further including electrode means for focusing said electron image, and an output screen for converting said focused image electron image into a visible intensified image of said electron image.
Claim 4
Dependent Claim
12 words
The apparatus of claim 1 wherein said scintillator layer is activated CsI.
Claim 5
Dependent Claim
24 words
The apparatus of claim 3 wherein said scintillator layer includes an activator material selected from the class consisting of TlI, NaI, Na, and LiI.
Claim 6
Dependent Claim
11 words
The apparatus of claim 1 wherein said scintillator layer is curved.
Claim 7
Dependent Claim
25 words
The apparatus of claim 1 wherein said scintillator layer is a layer of material condensed onto a support member in vacuum from the vapor phase.
Claim 8
Dependent Claim
13 words
The apparatus of claim 3 wherein said photocathode material includes cesium and antimony.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-06-01 | 1979-12-01 | 1980-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-01 | 1983-12-01 | 1984-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-01 | 1987-12-01 | 1988-06-01 | $7700.00 | Window Closed / Lapsed |