US3718078A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Smoothly granulated optical surface and method for making same
Assignee: Polaroid Corp
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Filing: 1970-12-31
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Granted: 1973-02-27
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Expires: 1990-12-31
Abstract
Abstract A method for forming a light-scattering surface in which the surface, made from a soluble material, is sprayed with droplets of a volatile solvent. After the droplets evaporate, the surface is found to be smoothly perturbated. Molds can be made of the perturbated surface from which duplicates can be pressed in large numbers and in a variety of materials. A surface perturbated according to the present process is useful in optical articles for randomly distributing, within a predetermined solid angle, light incident on said surface. Applications for the lightscattering surface include: focusing screens; fresnel condenser optics; and, non-glare windows.
Inventors
- 👤 W Plummer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:41
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/02; G02B5/0205; G02B5/021; G02B5/0215; G02B3/00; G02B3/02; G02B3/08; G02B5/0221; G02B5/0273; G02B5/0284; G03; G03B; G03B13/00; G03B13/18; G03B13/24; G03B13/26
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
23 words
The improved focusing screen described in claim 1, wherein the slope on the side of said granular shapes does not exceed three degrees.
Claim 2
Dependent Claim
24 words
The improved focusing screen described in claim 1, wherein the height of said granular shapEs is on the order of a wavelength of light.
Claim 3
Dependent Claim
72 words
On a focusing screen characterized by echelon mirror means for reflecting an image of a first aperture stop to a second aperture stop, the improvement comprising: a plurality of smooth granular contours on said echelon mirror means, said smooth granular contours characterized by a maximum slope of three degrees and a peak-to-valley height on the order of a wavelength of light, said contours and the interstices between them being free of cusps.
Claim 4
Dependent Claim
58 words
A fresnel lens, comprising: a first surface; a plurality of echelon rulings situate on said first surface of said fresnel lens; a second surface; and a plurality of smoothly contoured shapes, situate on at least one of said first and said second surfaces and randomly distributed thereon, for randomly dispersing light incident thereon within a predetermined solid angle.
Claim 5
Dependent Claim
46 words
The fresnel lens of claim 5, wherein said smoothly contoured shapes and the interstices between them are free of cusps and said shapes have a maximum peak-to-trough height of one light wavelength with a maximum slope on the sides of said shapes equal to 3* .
Claim 6
Dependent Claim
27 words
The fresnel lens of claim 6, wherein said plurality of smoothly contoured shapes is situated on said first surface as represented by said plurality of echelon rulings.
Claim 7
Dependent Claim
97 words
On a focusing screen, for a camera, having echelon means for forming an image of an aperture stop and specular means, on said echelon means, for reflecting light therefrom, the improvement comprising: granular shapes coextensive with said echelon means and randomly distributed and closely spaced thereon, said granular shapes characterized by smooth contours with both the granular shapes and the interstices between said granular shapes free of cusps, and said granular shapes having a maximum peak-to-trough height of one wavelength of light with a maximum slope on the sides of said granular shapes equal to 3* .
Claim 8
Independent Claim
58 words
A method comprising the steps of: forming an article having a surface made from a soluble material; spraying droplets of a solvent so said droplets impinge upon said surface; and evaporating said droplets which impinge upon said soluble material of said surface prevent said droplets from coalescing with droplets subsequently impinging upon said surface whereby said is reshaped.
Claim 9
Dependent Claim
44 words
The method described in claim 9, further comprising the steps of: changing the distance said droplets travel before they impinge on said surface so as to alter their size at said surface; and modifying said solvent to control its interaction with said soluble material.
Claim 10
Dependent Claim
40 words
The method described in claim 9, further comprising the steps of: dissolving some of said soluble material of said surface into said droplets which impinge upon said surface; and depositing the dissolved material onto said surface as said droplets evaporate.
Claim 11
Dependent Claim
29 words
The method described in claim 9, wherein said solble material is selected from the group consisting of: cellulose acetate butyrate and cellulose acetate propionate; and the solvent is 1,2-dichloroethane.
Claim 12
Dependent Claim
30 words
The method described in claim 9, wherein said soluble material is selected from the group consisting of: cellulose acetate butyrate and cellulose acetate propionate; and the volatile solvent is chloroform.
Claim 13
Dependent Claim
19 words
The method described in claim 9, further comprising the step of: duplicating said article after said surface is reshaped.
Claim 14
Independent Claim
72 words
A method for manufacturing an optical article, comprising the steps of: forming said optical article with a surface made from a soluble material; spraying droplets of a solvent so said droplets impinge upon said surface; and evaporating said droplets which impinge upon said soluble material of said surface prevent said droplets from coalescing with droplets subsequently impinging upon said surface whereby said surface is reshaped having smoothly contoured, randomly placed granular forms.
Claim 15
Dependent Claim
44 words
The method descriBed in claim 15, further comprising the steps of: changing the distance said droplets travel before they impinge on said surface so as to alter their size at said surface; and modifying said solvent to control its interaction with said soluble material.
Claim 16
Dependent Claim
40 words
The method described in claim 15, further comprising the steps of: dissolving some of said soluble material of said surface into said droplets which impinge upon said surface; and depositing the dissolved material onto said surface as said droplets evaporate.
Claim 17
Dependent Claim
29 words
The method described in claim 15, wherein said soluble material is selected from the group consisting of: cellulose acetate butyrate and cellulose acetate propionate; and the solvent is 1,2-dichloroethane.
Claim 18
Dependent Claim
29 words
The method described in claim 15, wherein said soluble material is selected from the group consisting of: cellulose acetate butyrate and cellulose acetate propionate; and the solvent is chloroform.
Claim 19
Dependent Claim
19 words
The method described in claim 15, further comprising the step of: duplicating said article after said surface is reshaped.
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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) | 1976-02-27 | 1976-08-28 | 1977-02-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-27 | 1980-08-28 | 1981-02-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-27 | 1984-08-28 | 1985-02-27 | $7700.00 | Window Closed / Lapsed |