Patent US3687782A successfully refreshed from Google Patents.
US4255481A
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Mask for selectively transmitting therethrough a desired light radiant energy
Assignee: AT&T Inc
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Filing: 1979-09-26
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Granted: 1981-03-10
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Expires: 1999-09-26
Abstract
Abstract A mask for selectively transmitting therethrough a desired light radiant energy is disclosed. The mask comprises a stress-relieved, essentially dimensionally stable base, comprising a copolymer of tetrafluoroethylene and hexafluoropropylene, which is capable of transmitting therethrough the light radiant energy. A blocking film is deposited on at least a portion of the base for blocking the transmission of the light radiant energy through the portion of the base.
Inventors
- 👤 Donald Dinella
- 👤 Ching-Ping Wong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 01:10
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/62; B; B32; B32B; B32B15/00; B32B15/04; B32B15/08; G03F1/50; H; H05; H05K; H05K3/00; H05K3/0002; H05K3/10; H05K3/18; H05K3/181; H05K3/182; H05K3/185; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802; Y10T428/24917; Y10T428/26; Y10T428/266; Y10T428/31504; Y10T428/3154; Y10T428/31544
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
91 words
A mask for selectively transmitting therethrough a desired light radiant energy, which comprises: a stress-relieved base, comprising a copolymer of tetrafluoroethylene and hexafluoropropylene, which has been heat treated for a period of time sufficient to render it essentially dimensionally stable and which is capable of transmittting therethrough the light radiant energy, said copolymer base having a thickness of from 5 to 10 mils; and a blocking film formed on at least a portion of said base for blocking the transmission of the light radiant energy through said portion of said base.
Claim 2
Dependent Claim
91 words
A mask for selectively transmitting therethrough a desired light radiant energy, which comprises: a stress-relieved base, comprising a copolymer of tetrafluoroethylene and hexafluoropropylene, which has been heat treated for a period of time sufficient to render it essentially dimensionally stable and which is capable of transmittting therethrough the light radiant energy, said copolymer base having a thickness of from 5 to 10 mils; and a blocking film formed on at least a portion of said base for blocking the transmission of the light radiant energy through said portion of said base.
Claim 3
Dependent Claim
14 words
The mask as defined in claim 1 wherein said blocking film comprises a metal.
Claim 4
Dependent Claim
12 words
The mask as defined in claim 2 wherein said metal comprises copper.
Claim 5
Dependent Claim
16 words
The mask as defined in claim 1 wherein said blocking film comprises a non-transmitting plastic film.
Claim 6
Dependent Claim
29 words
The mask as defined in claim 4 wherein said non-transmitting plastic film comprises a member of the group consisting of nitrocellulose, lacquer and vinyl chloride resin containing a dye.
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) | 1984-03-09 | 1984-09-08 | 1985-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-09 | 1988-09-08 | 1989-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-09 | 1992-09-08 | 1993-03-10 | $7700.00 | Window Closed / Lapsed |