Patent US3909111A successfully refreshed from Google Patents.
US3909111A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Controlled angle viewing screens by interference techniques
Assignee: RCA Licensing Corp
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Filing: 1974-02-27
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Granted: 1975-09-30
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Expires: 1994-02-27
Abstract
Abstract A hardened gelatin film on a transparent substrate forms a rear projection viewing screen providing high efficiency and uniformity of illumination with predetermined scattering characteristics over a relatively wide field of view. This is accomplished by the presence within the gelatin film of a scattering pattern corresponding to a certain three-dimensional interference pattern recorded therein. This certain interference pattern results from the exposure of the gelatin film, after light sensitization thereof, with substantially coherent light which has passed through a diffusing medium having a given cross sectional area which is spaced a given distance from the film, followed by the development of the exposed film by a process which includes rapid drying of the film after immersion thereof.
Inventors
- 👤 Dietrich Meyerhofer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:04
CPC Classifications
G; G03; G03B; G03B21/00; G03B21/54; G03B21/56; G03B21/60; G03B21/62
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
130 words
A REAR PROJECTION VIEWING SCREEN COMBINING HIGH EFFICIENCY AND UNIFORMITY OF ILLUMINATION WITH PREDETERMINED SCATTERING CHARACTERISTICS OVER A RELATIVELY WIDE FIELD OF VIEW ABOUT THE NORMAL TO SAID SCREEN, SAID SCREEN COMPRISING: A. A TRANSPARENT SUBSTRATE, SAID SUBSTRATE HAVING A PAIR OF OPPOSING SURFACES, AND B. A HARDENED GELATIN FILM ON ONE OF SAID SURFACES OF SAID SUBSTRATE, SAID GELATIN FILM EXHIBITING A SCATTERING PATTERN CORRESPONDING TO A CERTAIN THREE-DIMENSIONAL INTERFERENCE PATTERN RECORDED THEREIN, THE DISTRIBUTION OF REGIONS OF CONSTRUCTIVE AND DESTRUCTIVE INTERFERENCE OF SAID RECORDED CERTAIN INTERFERENCE PATTERN BEING DISTRIBUTED SUBSTANTIALLY RANDOMLY WITH RESPECT TO THE PLANE OF SAID SCREEN AND IN DETERMINED PREFERRED ORIENTATION WITH RESPECT TO THE NORMAL TO SAID SCREEN, WHEREBY SAID DISTRIBUTION OF SAID RECORDED CERTAIN INTERFERENCE PATTERN PREDETERMINES SAID SCATTERING CHARACTERISTICS OF SAID SCREEN.
Claim 2
Dependent Claim
130 words
A REAR PROJECTION VIEWING SCREEN COMBINING HIGH EFFICIENCY AND UNIFORMITY OF ILLUMINATION WITH PREDETERMINED SCATTERING CHARACTERISTICS OVER A RELATIVELY WIDE FIELD OF VIEW ABOUT THE NORMAL TO SAID SCREEN, SAID SCREEN COMPRISING: A. A TRANSPARENT SUBSTRATE, SAID SUBSTRATE HAVING A PAIR OF OPPOSING SURFACES, AND B. A HARDENED GELATIN FILM ON ONE OF SAID SURFACES OF SAID SUBSTRATE, SAID GELATIN FILM EXHIBITING A SCATTERING PATTERN CORRESPONDING TO A CERTAIN THREE-DIMENSIONAL INTERFERENCE PATTERN RECORDED THEREIN, THE DISTRIBUTION OF REGIONS OF CONSTRUCTIVE AND DESTRUCTIVE INTERFERENCE OF SAID RECORDED CERTAIN INTERFERENCE PATTERN BEING DISTRIBUTED SUBSTANTIALLY RANDOMLY WITH RESPECT TO THE PLANE OF SAID SCREEN AND IN DETERMINED PREFERRED ORIENTATION WITH RESPECT TO THE NORMAL TO SAID SCREEN, WHEREBY SAID DISTRIBUTION OF SAID RECORDED CERTAIN INTERFERENCE PATTERN PREDETERMINES SAID SCATTERING CHARACTERISTICS OF SAID SCREEN.
Claim 3
Dependent Claim
24 words
A viewing screen in accordance with claim 1 wherein the thickness of said gelatin film is in the range of 6 to 20 microns.
Claim 4
Dependent Claim
17 words
A viewing screen in accordance with cLaim 2 in which said gelatin film is a dichromated gelatin.
Claim 5
Dependent Claim
15 words
A viewing screen in accordance with claim 3 in which said film includes ammonium dichromate.
Claim 6
Dependent Claim
94 words
A viewing screen in accordance with claim 1, wherein said certain recorded interference pattern results from the exposure of said gelatin film, after light sensitization thereof, with substantially coherent light which has passed through a diffusing medium having a given cross sectional area which is spaced a given distance from said film, and the development of said exposed film by a process which includes rapid drying of said film after immersion thereof, said preferred orientations being determined by the size of the dimensions of said given area and the size of said given distance.
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) | 1978-09-29 | 1979-03-31 | 1979-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-29 | 1983-03-31 | 1983-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-29 | 1987-03-31 | 1987-09-30 | $7700.00 | Window Closed / Lapsed |