US3897140A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multilayer solar filter reducing distortive diffraction
Assignee: Individual
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Filing: 1974-06-14
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Granted: 1975-07-29
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Expires: 1994-06-14
Abstract
Abstract A filter for blocking out harmful solar radiation for direct viewing or for photographic purposes employs a plurality of flexible, transparent resin film layers which are coated with metal to achieve optical clarity and to effectively shield the user from most of the sun''s energy while allowing enough light to pass through the filter. The total thickness of the resin material is not more than approximately 0.002 inch, and the total thickness of the metal on the film layers provides an opaqueness to allow passage of approximately 0.01 percent sunlight.
Inventors
- 👤 Roger W Tuthill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 04:10
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B29; B29D; B29D11/00; B29D11/00634; B32B27/36; G; G02; G02B; G02B5/00; G02B5/20; G02B5/205; B32B2255/00; B32B2255/10; B32B2255/20; B32B2255/205; B32B2367/00; B32B2551/00; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24273; Y10T428/24322
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
113 words
A solar filter for an astronomical optical instrument, the solar filter consisting essentially of a plurality of flexible, transparent resin film layers each having a metal coating, the metal coated film layers overlying each other, the film layers having a total thickness not more than approximately 0.002 inch and the metal coatings having a total thickness to provide an opaqueness to allow passage of approximately 0.01 percent sunlight, each of the film layers being of a thinness so that there are pinholes therein, whereby the possibility of a pinhole in one film layer being aligned with a pinhole in another film layer is minimized thus reducing the distortive diffraction effect of said pinholes.
Claim 2
Dependent Claim
113 words
A solar filter for an astronomical optical instrument, the solar filter consisting essentially of a plurality of flexible, transparent resin film layers each having a metal coating, the metal coated film layers overlying each other, the film layers having a total thickness not more than approximately 0.002 inch and the metal coatings having a total thickness to provide an opaqueness to allow passage of approximately 0.01 percent sunlight, each of the film layers being of a thinness so that there are pinholes therein, whereby the possibility of a pinhole in one film layer being aligned with a pinhole in another film layer is minimized thus reducing the distortive diffraction effect of said pinholes.
Claim 3
Dependent Claim
19 words
A solar filter according to claim 1 wherein the film layers each have a thickness of approximately 0.00035 inch.
Claim 4
Dependent Claim
17 words
A solar filter according to claim 2 wherein each of the film layers is a polyethylene terephthalate.
Claim 5
Dependent Claim
14 words
A solar filter according to claim 1 wherein the metal coatings are of aluminum.
Claim 6
Dependent Claim
23 words
A solar filter according to claim 4 wherein the aluminum coatings provide a resistance of approximately 0.4 to 0.9 ohm per square unit.
Claim 7
Dependent Claim
25 words
A solar filter according to claim 1 wherein the plurality of film layers comprises two film layers each having a coating on one side only.
Claim 8
Dependent Claim
25 words
A solar filter according to claim 6 wherein each metal coating is aluminum having a resistance of approximately 0.8 to 1.8 ohm per square unit.
Claim 9
Dependent Claim
19 words
A solar filter according to claim 7 wherein the film layers each have a thickness of approximately 0.00035 inch.
Claim 10
Dependent Claim
17 words
A solar filter according to claim 8 wherein each of the film layers is a polyethylene terephthalate.
Claim 11
Dependent Claim
113 words
A solar filter for an astronomical optical instrument, the solar filter consisting essentially of a plurality of flexible, transparent resin film layers each having an aluminum coating on one side only, the aluminum coated film layers overlying each other, the film layers having a total thickness not more than approximately 0.002 inch, and the aluminum coatings having a resistance of approximately 0.4 to 0.9 ohm per square unit, each of the film layers being of a thinness so that there are pinholes therein, whereby the possibility of a pinhole in one film layer being aligned with a pinhole in another film layer is minimized thus reducing the distortive diffraction effect of said pinholes.
Claim 12
Dependent Claim
113 words
A solar filter for an astronomical optical instrument, the solar filter consisting essentially of a plurality of flexible, transparent resin film layers each having an aluminum coating on one side only, the aluminum coated film layers overlying each other, the film layers having a total thickness not more than approximately 0.002 inch, and the aluminum coatings having a resistance of approximately 0.4 to 0.9 ohm per square unit, each of the film layers being of a thinness so that there are pinholes therein, whereby the possibility of a pinhole in one film layer being aligned with a pinhole in another film layer is minimized thus reducing the distortive diffraction effect of said pinholes.
Claim 13
Dependent Claim
35 words
A solar filter according to claim 10 wherein there are two aluminum coated resin film layers, and wherein the coating on each layer has a resistance of approximately 0.8 to 1.8 ohm per square unit.
Claim 14
Dependent Claim
17 words
A solar filter according to claim 11 wherein each of the film layers is a polyethylene terephthalate.
Claim 15
Dependent Claim
19 words
A solar filter according to claim 12 wherein the film layers each have a thickness of approximately 0.00035 inch.
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) | 1978-07-28 | 1979-01-27 | 1979-07-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-28 | 1983-01-27 | 1983-07-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-28 | 1987-01-27 | 1987-07-29 | $7700.00 | Window Closed / Lapsed |