US3773540A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cathodochromic image screen and method for preparing cathodochromic sodalite for said image screen
Assignee: RCA Licensing Corp
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Filing: 1971-05-27
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Granted: 1973-11-20
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Expires: 1991-05-27
Abstract
Abstract An image screen of a dark trace cathode ray tube comprises a substrate having a novel sodalite cathodochromic layer thereon. The novel sodalite is characterized in that it is spherically shaped, porous and contains a sodium halide deficiency of 10 - 20 weight percent. The novel sodalite is prepared by a hydrothermal growth technique employing excess sodium hydroxide and sodium halide and wherein the reaction vessel is heated to a uniform temperature and rapidly cooled to prevent growth of dedcahedral crystals.
Inventors
- 👤 I Shidlovsky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 09:06
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/02; H01J29/10; H01J29/14; C; C01; C01B; C01B33/00; C01B33/20; C01B33/26; C01B33/28; C01B33/2807; C01B33/2892; C09; C09K; C09K9/00; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24355; Y10T428/24372; Y10T428/24413; Y10T428/25; Y10T428/258
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
22 words
The image screen recited in claim 1 wherein said sodalite has a sodium halide deficiency of from 10 - 20 weight percent.
Claim 2
Dependent Claim
40 words
The image screen recited in claim 1 wherein said sodalite particles have a sodium halide deficiency from stoichiometry of from 10 - 20 weight percent and wherein said image screen has a saturation cathodochromic contrast ratio of at least 20:1.
Claim 3
Dependent Claim
28 words
The image screen recited in claim 3 wherein at least 90 percent of said sodalite particles have a particle size of from 4 - 6 microns in diameter.
Claim 4
Dependent Claim
80 words
In a dark trace cathode ray tube, an image screen comprising a substrate having a layer of cathodochromic sodalite particles thereon of the type wherein the halogen ion is a bromide ion, said sodalite characterized in that the particles are spherical in shape having an average particle size of from 4 - 6 microns in diameter and contain less than the stoichiometric quantity of NaBr, said cathode ray tube having a cathodochromic contrast ratio at saturation of at least 20:1.
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) | 1976-11-19 | 1977-05-21 | 1977-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-19 | 1981-05-21 | 1981-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-19 | 1985-05-21 | 1985-11-20 | $7700.00 | Window Closed / Lapsed |