US4572984A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Blue luminescent cathode ray tube device with improved color filtering system
Assignee: Philips North America LLC
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Filing: 1984-04-13
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Granted: 1986-02-25
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Expires: 2004-04-13
Abstract
Abstract The invention relates to a cathode ray tube device for generating a bright blue light of the type that is particularly useful for projection color television and information display. To filter out undesired radiation emitted by a silver-activated zinc sulfide phosphor, there is located in the path of blue radiation a concentrated solution of a soluble erbium salt and Methyl Violet 2B.
Inventors
- 👤 Brian J. Fitzpatrick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 10:01
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/86; H01J29/89; H01J29/898
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
115 words
A cathode-ray tube device for generating a bright blue light spot comprising: a cathode-ray tube including an evacuated envelope with a face plate; means, located within said envelope, to generate an electronic beam; a silver-activated zinc sulfide phosphor, which emits blue radiation when excited by electrons from said electronic beam and located within said envelope; and in which device there is positioned outside of the external surface of said face plate and in the path of said blue radiation, a light beam filtering means comprising a container, which at least in the path of said blue radiation is transparent to said radiation, containing a concentrated solution of a soluble erbium salt and Methyl Violet 2B.
Claim 2
Dependent Claim
115 words
A cathode-ray tube device for generating a bright blue light spot comprising: a cathode-ray tube including an evacuated envelope with a face plate; means, located within said envelope, to generate an electronic beam; a silver-activated zinc sulfide phosphor, which emits blue radiation when excited by electrons from said electronic beam and located within said envelope; and in which device there is positioned outside of the external surface of said face plate and in the path of said blue radiation, a light beam filtering means comprising a container, which at least in the path of said blue radiation is transparent to said radiation, containing a concentrated solution of a soluble erbium salt and Methyl Violet 2B.
Claim 3
Dependent Claim
45 words
The cathode-ray tube device of claim 1 wherein the solution contains a solvent which is a mixture of water and an alcohol selected from the group consisting of ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, glycerol, methanol, ethanol, propanol, isopropanol and benzyl alcohol, and mixtures thereof.
Claim 4
Dependent Claim
27 words
The cathode-ray tube device of claim 2 wherein the erbium salt is selected from the group consisting of erbium chloride, erbium bromide, erbium iodide and erbium nitrate.
Claim 5
Dependent Claim
32 words
The cathode-ray tube device of claim 3 wherein the solution contains from 20% to 40% by weight of the erbium salt and 0.0004% to 0.0008% by weight of the Methyl Violet 2B.
Claim 6
Dependent Claim
24 words
The cathode-ray tube device of claim 2 wherein the solvent is a mixture of water and up to 80% by weight of ethylene glycol.
Claim 7
Dependent Claim
24 words
The cathode-ray tube device of claim 3 wherein the solvent is a mixture of water and up to 80% by weight of ethylene glycol.
Claim 8
Dependent Claim
24 words
The cathode-ray tube device of claim 4 wherein the solvent is a mixture of water and up to 80% by weight of ethylene glycol.
Claim 9
Dependent Claim
14 words
The cathode-ray tube device of claim 6 wherein the erbium salt is erbium nitrate.
Claim 10
Dependent Claim
14 words
The cathode-ray tube device of claim 7 wherein the erbium salt is erbium nitrate.
Claim 11
Dependent Claim
34 words
The cathode-ray tube device of claim 9 wherein the solution contains about 28% by weight of erbium nitrate and about 0.0006 by weight of Methyl Violet 2B in a 50% water-50% ethylene glycol solution.
Claim 12
Dependent Claim
22 words
The cathode-ray tube device of claim 1 wherein the light filtering means is sealed to the outer surface of the face plate.
Claim 13
Dependent Claim
22 words
The cathode-ray tube device of claim 2 wherein the light filtering means is sealed to the outer surface of the face plate.
Claim 14
Dependent Claim
22 words
The cathode-ray tube device of claim 8 wherein the light filtering means is sealed to the outer surface of the face plate.
Claim 15
Dependent Claim
22 words
The cathode-ray tube device of claim 10 wherein the light filtering means is sealed to the outer surface of the face plate.
References Cited (Backward Citations)
US3873868A
Cited
GB2098393A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-02-24 | 1989-08-26 | 1990-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-24 | 1993-08-26 | 1994-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-24 | 1997-08-26 | 1998-02-25 | $7700.00 | Window Closed / Lapsed |