US3768898A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Continuously-variable, solid-angle filter
Assignee: Spectral Data Corp
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Filing: 1969-10-29
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Granted: 1973-10-30
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Expires: 1989-10-29
Abstract
Abstract A pair of coaxially mounted, cylindrical, neutral-density filter members geared together for counterrotation, one member being of linearly increasing density clockwise and the other member being of linearly decreasing density clockwise. An arrangement similar to (1) in which parallel linear filter members replace the coaxial cylindrical filter members. A rheostat-controlled light source, a slit mask, a pair of movable beds, gears for driving the beds past the slit at prescribed speeds, and a pair of light-sensitvve film strips respectively mounted on the beds for making the filter members. An arrangement of the filter members in a spectral zonal color reconnaissance viewer.
Inventors
- 👤 E Yost
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:12
CPC Classifications
G; G03; G03B; G03B33/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
259 words
A spectral zonal photographic method of discovering information about a scene comprising the steps of making black and white representations of said scene at different zones of the actinic electomagnetic spectrum using a multi lens camera respectively illuminating each of a plurality of black - and white photographic representations of the scene with each of a plurality of illuminating lights, projecting images of said respective representations on a viewing screen in superimposed relation, filtering the lights respectively illuminating each of said representations using a first set of filter elements associated with the lights so that each of said illuminating lights are respectively of uniform intensity over the area of each of said representations, varying the said first set of filter elements so that the intensity of the illumination of each representation is continuously varied, individually coloring said illuminating lights using color means to impart a desired hue to said projected images, respectively superimposing white desaturating lights on the projected representation to desaturate the color of said projected representations thereby varying the saturation without changing the hue, and filtering each of said desaturating lights using a second set of filters associated with the desaturating lights to vary the intensity of said desaturating lights so that said lights are of uniform intensity over the area of each of said representations, and varying the said second set of filter elements so that the intensity of each desaturating light is continuously varied, whereby the brightness and saturation of each of said projected images are continuously and independently adjustable without alteration of color temperature.
Claim 2
Dependent Claim
259 words
A spectral zonal photographic method of discovering information about a scene comprising the steps of making black and white representations of said scene at different zones of the actinic electomagnetic spectrum using a multi lens camera respectively illuminating each of a plurality of black - and white photographic representations of the scene with each of a plurality of illuminating lights, projecting images of said respective representations on a viewing screen in superimposed relation, filtering the lights respectively illuminating each of said representations using a first set of filter elements associated with the lights so that each of said illuminating lights are respectively of uniform intensity over the area of each of said representations, varying the said first set of filter elements so that the intensity of the illumination of each representation is continuously varied, individually coloring said illuminating lights using color means to impart a desired hue to said projected images, respectively superimposing white desaturating lights on the projected representation to desaturate the color of said projected representations thereby varying the saturation without changing the hue, and filtering each of said desaturating lights using a second set of filters associated with the desaturating lights to vary the intensity of said desaturating lights so that said lights are of uniform intensity over the area of each of said representations, and varying the said second set of filter elements so that the intensity of each desaturating light is continuously varied, whereby the brightness and saturation of each of said projected images are continuously and independently adjustable without alteration of color temperature.
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) | 1976-10-29 | 1977-04-30 | 1977-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-29 | 1981-04-30 | 1981-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-29 | 1985-04-30 | 1985-10-30 | $7700.00 | Window Closed / Lapsed |