US3722998A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid crystal apparatus for reducing contrast
Assignee: Eastman Kodak Co
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Filing: 1970-10-19
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Granted: 1973-03-27
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Expires: 1990-10-19
Abstract
Abstract An apparatus is provided for masking a projected image from a slide transparency which apparatus includes interposing in the projection path a photoconductor-liquid crystal sandwich comprising a layered structure having in order, a first transparent electrode, a transparent layer, a liquid crystal layer and a second transparent electrode, and including means for applying a potential between the transparent electrodes. Upon projection of the transparency image, the lighter areas will cause the photoconductive material to become more conductive than will the darker areas so that the corresponding areas of the liquid crystal layer will become diffuse thereby diffusing some of the light away from the optical system in the brighter areas to provide an image on the photosensitive surface which has less contrast than the original transparency image.
Inventors
- 👤 J Morse
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:30
CPC Classifications
G; G03; G03G; G03G5/00; G03G5/14; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/1313
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
148 words
Apparatus for projecting a slide transparency image, having lighter and darker areas, onto a photosensitive surface at reduced contrast, said apparatus comprising: a mount for supporting a slide transparency in a projection plane; means for supporting the photosensitive surface at an image plane along said projection path; means for projecting the slide transparency image along a projection path onto the photosensitive surface; and a layered photoconductive-liquid crystal sandwich interposed in said projection path, said sandwich having means for applying a potential thereacross so that the lighter areas selectively increase the conductivity of the photoconductive layer to cause corresponding areas of the liquid crystal layer to diffuse light to a greater extent that in those portions corresponding to the darker areas so that the image projected along said projection path through said sandwich to be formed on the photosensitive surfaces has less contrast than the original slide transparency image.
Claim 2
Dependent Claim
173 words
Apparatus for projecting an image onto an image plane including means for supporting an image bearing member in an object plane spaced from said image plane, an illumination source for illuminating a supported image bearing member to form an image pattern, means for projecting the pattern from said illuminated image bearing member along a projection path to said image plane, and intermediate image storage means located between said illumination source and said image plane, said image storage means comprising a layered structure including first and second transparent electrodes, a substantially transparent photoconductive layer and a liquid crystal layer sandwiched between said first and second transparent electrodes, and means for applying a potential between said first and second electrodes to render said storage means capable of storing an image therein, said layered structure being oriented so that said photoconductive layer is positioned to receive the image pattern from a supported, illuminated, image bearing member and, upon application of potential to said electrodes, form a corresponding pattern of light diffusion in said liquid crystal layer.
Claim 3
Dependent Claim
24 words
The apparatus of claim 3 wherein said image bearing member support means is located between said illumination source and said intermediate image storage means.
Claim 4
Dependent Claim
73 words
For use in image projection apparatus, an improved device for imagewise regulating light transmission, said device comprising a layered structure having: a first transparent electrode; a transparent photoconductive layer in contiguous relationship to said first transparent electrode; a liquid crystal layer in contiguous relationship to said photoconductive layer; a second transparent electrode in contiguous relationship to said liquid crystal layer; and means for applying a potential between said first and second transparent electrodes.
Claim 5
Dependent Claim
203 words
Apparatus for forming at an image plane an illumination pattern related to the image pattern on a selected image bearing medium, said apparatus comprising: image storage means spaced from said image plane, said image storage means comprising a pair of transparent electrodes, a liquid crystal layer, a transparent photoconductive layer, said liquid crystal layer and said photoconductive layer being sandwiched between said electrodes, and means for applying an electrical potential between said electrodes, said image storage means being responsive to applications thereto of a radiation pattern corresponding to the image on said image bearing medium while said electric potential is applied to form in said liquid crystal layer an intermediate image pattern of clear and diffuse areas imagewise related to said radiation pattern; and means for applying said radiation pattern from said image bearing medium to said image storage means to form said intermediate image pattern and foR projecting light through said image bearing medium and said intermediate image pattern and along a path to said image plane, including means located in said path between said image storage means and said image plane for imaging the light pattern projected through said image bearing medium and said image storage means at said image plane.
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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) | 1976-03-26 | 1976-09-25 | 1977-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-26 | 1980-09-25 | 1981-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-26 | 1984-09-25 | 1985-03-27 | $7700.00 | Window Closed / Lapsed |