Patent US3787238A successfully refreshed from Google Patents.
US3787238A
Expired / Lapsed
US
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Fluorescent screens
Assignee: General Electric Co
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Filing: 1971-12-10
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Granted: 1974-01-22
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Expires: 1991-12-10
Abstract
Abstract A fluorescent screen for use as an image intensifying screen is provided having a support, a light reflecting layer, a layer of fluorescent particles and an outer protective coating. The protective coating is a polymeric material having incorporated therein an effective amount of a transparent binary polydimethylsiloxane-polyalkylmethacrylate block copolymer.
Inventors
- 👤 P Juliano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:59
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/02; H01J29/10; H01J29/18; H01J29/28; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31652; Y10T428/31663
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
19 words
The screen of claim 1, having a light reflective layer between the support and the layer of luminescent material.
Claim 2
Dependent Claim
66 words
The screen of claim 2, wherein said film forming polymer is a member selected from the group consisting of a polyalkylmethacrylate wherein the alkyl group contains one to four carbon atoms, a methylmethacrylate copolymer with other alkylmethacrylates wherein the glass transition temperature is in the range of 30*-100*C., cellulose acetate, cellulose propionate, cellulose acetate propionate, cellulose acetate butyrate, nitrocellulose, polyvinylchloride and copolymers of vinylchloride and vinylacetate.
Claim 3
Dependent Claim
32 words
The screen of claim 2, wherein the block copolymer consists essentially of sequentially arranged blocks of polydimethylsiloxane and polyalkylmethacrylate, wherein the block copolymer is substantially free of homopolymerized polyalkylacrylate and homopolymerized polydimethylsiloxane.
Claim 4
Dependent Claim
19 words
The screen of claim 4, wherein the block copolymer consists essentially of sequentially arranged blocks of polydimethylsiloxane aNd polymethylmethacrylate.
Claim 5
Dependent Claim
33 words
The screen of claim 5, wherein the block copolymer consists essentially from about 5-90 percent by weight of the polydimethylsiloxane blocks and correspondingly from about 10-95 percent by weight of the polymethylmethacrylate blocks.
Claim 6
Dependent Claim
26 words
The screen of claim 6, wherein the protective layer consists essentially of a polymethylmethacrylate film having incorporated therein 0.01-5.0 percent by weight of the block copolymer.
Claim 7
Dependent Claim
28 words
The screen of claim 6, wherein the protective layer consists essentially of a cellulose acetate butyrate polymer having incorporated therein 0.5-5.0 percent by weight of the block copolymer.
References Cited (Backward Citations)
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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) | 1977-01-21 | 1977-07-23 | 1978-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-21 | 1981-07-23 | 1982-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-21 | 1985-07-23 | 1986-01-22 | $7700.00 | Window Closed / Lapsed |