US3758207A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Masking printer
Assignee: Eastman Kodak Co
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Filing: 1972-06-14
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Granted: 1973-09-11
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Expires: 1992-06-14
Abstract
Abstract A masking device is provided for reducing contrast of a projected slide transparency image which includes a photoconductive-liquid crystal layer which is exposed to the slide transparency image by a masking light to form a masking image thereon. Subsequently, a projection light is projected through the masking image formed on the sandwich structure and through the slide transparency to form a reduced contrast image on a photosensitive surface.
Inventors
- 👤 E Letzer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:45
CPC Classifications
G; G03; G03C; G03C5/00; G03C5/08; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/135; G03B; G03B27/00; G03B27/32
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
190 words
In an apparatus for projecting a transparency image onto a photosensitive material including a light source, means for supporting a transparency in a projection plane, means for projecting light along a projection path to project the transparency image onto the photosensitive material, and means for supporting the photosensitive material in an image plane, an improvement for reducing contrast of the projected image on the photosensitive member, said improvement comprising: a layered masking means in said projection path including in order: a first transparent electrode adjacent said transparency supporting means; a photoconductive layer positioned between said first electrode and the photosensitive material support means and in contiguous relationship to said first electrode; a liquid crystal layer in contiguous relation-ship to said photoconductive layer; and a second transparent electrode in contiguous relationship to said liquid crystal layer; means for applying a potential between said first and second electrodes; and means for projecting a masking light through said transparency onto said photoconductive layer to form a mask in said liquid crystal layer having light diffusing characteristics which vary in accordance with the amount of light which strikes corresponding portions of said photoconductive layer.
Claim 2
Dependent Claim
157 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 the slide transparency in a projection plane; means for projecting the slide transparency image along a projection path onto the photosensitive surface; means for supporting the photosensitive surface at an image plane along said projection path; a layered photoconductive-liquid crystal 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 to diffuse light to a greater extent than in those portions corresponding to the darker areas when exposed to a masking light so that the projected image formed on the photosensitive surface has less contrast than said slide transparency image; and means for projecting said masking light through said slide transparency onto said sandwich prior to projection of said slide transparency image.
Claim 3
Independent Claim
114 words
A method of reducing the contrast of an image projected along a projection path, said method comprising the steps of: projecting a masking light through a transparency original, having an image with lighter and darker areas, to project the image onto a layered photoconductive-liquid crystal 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 to diffuse light to a greater extent than in those portions corresponding to tHe darker areas; and projecting an image along said projection path using said photoconductive-liquid crystal sandwich as a mask to reduce the contrast of said projected image.
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) | 1976-09-10 | 1977-03-12 | 1977-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-10 | 1981-03-12 | 1981-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-10 | 1985-03-12 | 1985-09-11 | $7700.00 | Window Closed / Lapsed |