US3830591A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Illumination apparatus
Assignee: Eastman Kodak Co
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Filing: 1973-05-04
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Granted: 1974-08-20
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Expires: 1993-05-04
Abstract
Abstract For use in a document reproducing apparatus such as a planetary microfilmer, apparatus is disclosed which compensates for Cos4 theta light intensity fall-off of an illuminated document as projected by an objective lens to thereby produce a uniform exposure of an image of the document to be photographed. The apparatus includes a source of illumination, a light reflecting surface for reflecting light from the source off a document to be photographed to vary the intensity of illumination of the document in a first direction along the document to compensate for Cos4 theta fall-off in such first direction, and a plurality of spaced light blocking bars disposed relative to the light source to vary the intensity of illumination of the document in a second direction along the document to compensate for Cos4 theta fall-off in such second direction.
Inventors
- 👤 R Albrecht
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 21:21
CPC Classifications
G; G03; G03B; G03B27/00; G03B27/32; G03B27/52; G03B27/54; G03B27/542
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
195 words
In a planetary microfilmer having a copyboard defining an area for receiving a document to be reproduced, a source of illumination disposed below said copyboard for illuminating said area and a photographic station located above said copyboard and including a lens disposed optically off-axis from said source and adapted to receive light from said source reflected off the copyboard and project same upon a film plane, the improvement comprising: a. a plurality of light reflecting strips disposed between said source and said area to uniformly vary the intensity of the illumination of light from said source at said area along a first direction to compensate for Cos4 theta fall-off in said first direction as viewed by said lens; b. at least one light attenuator bar disposed relative to said source between said reflecting strips and said source to uniformly vary the intensity of illumination of light from said source at said area along a second direction orthogonal to said first direction to compensate for Cos4 theta fall-off in said second direction as viewed by said lens; and c. a light diffuser disposed between said bar and said light source for diffusing light from said source.
Claim 2
Dependent Claim
195 words
In a planetary microfilmer having a copyboard defining an area for receiving a document to be reproduced, a source of illumination disposed below said copyboard for illuminating said area and a photographic station located above said copyboard and including a lens disposed optically off-axis from said source and adapted to receive light from said source reflected off the copyboard and project same upon a film plane, the improvement comprising: a. a plurality of light reflecting strips disposed between said source and said area to uniformly vary the intensity of the illumination of light from said source at said area along a first direction to compensate for Cos4 theta fall-off in said first direction as viewed by said lens; b. at least one light attenuator bar disposed relative to said source between said reflecting strips and said source to uniformly vary the intensity of illumination of light from said source at said area along a second direction orthogonal to said first direction to compensate for Cos4 theta fall-off in said second direction as viewed by said lens; and c. a light diffuser disposed between said bar and said light source for diffusing light from said source.
Claim 3
Dependent Claim
30 words
The invention as set forth in claim 1 wherein there are three attenuator bars arranged in two rows with two of said bars being disposed in one of said rows.
References Cited (Backward Citations)
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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) | 1977-08-19 | 1978-02-18 | 1978-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-19 | 1982-02-18 | 1982-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-19 | 1986-02-18 | 1986-08-20 | $7700.00 | Window Closed / Lapsed |