Patent US3922085A successfully refreshed from Google Patents.
US3922085A
Expired / Lapsed
US
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Illuminator for microphotography
Assignee: Tamarack Scientific Co Inc
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Filing: 1974-08-22
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Granted: 1975-11-25
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Expires: 1994-08-22
Abstract
Abstract The disclosure is of a system of microphotography by which photographic transparencies of a scale of the order of 2.5 inches square may be optically projection printed at a reduced scale, e.g., at 10 to 1 reduction, onto a sensitized surface. The system has a present application to production by photoengraving techniques of electronic circuits of the order of 0.25 inch X 0.25 inch, with attainment of improved uniformity of circuit lines throughout. The system includes an arc source, collector, and a double matrix lenticular light integrator for uniform illumination of the transparency, and a 1 to 1 light projection system including an arc-illuminated aperture, and a relay lens for forming an image thereof inside the entrance pupil of the final reduction projection, with the circuit transparency located just beyond the relay lens, where it is very uniformly illuminated. A neutral density (non-color selective) filter has a radial transmission characteristic, and produces extraordinary uniformity in the final printing image.
Inventors
- 👤 Ronald E Sheets
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 05:03
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70058; G03F7/70191; G03B; G03B27/00; G03B27/32; G03B27/52; G03B27/54; G03B27/545; G03F7/70216; G03F7/70241
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
154 words
In an illuminator for microphotography, the combination of: a primary light source in the form of an arc, means for collecting light from said source and directing it to a source image in a focal plane, optical means including a relay lens for collecting divergent light from said source image and directing it toward a focus, means for supporting a photographic transparency forwardly of said relay lens, to be illuminated thereby, a projection lens whose entrance pupil receives said directed light and which forms a real, inverted image of said transparency, to a predetermined scale, in front thereof, and a neutral density filter spaced between said relay lens and said source image, the transmission characteristic of said filter increasing radially outward from its center toward its periphery in a predetermined manner compensating for progressive radially outward decrease in intensity tending to occur in the divergent light between said source image and said relay lens.
Claim 2
Dependent Claim
154 words
In an illuminator for microphotography, the combination of: a primary light source in the form of an arc, means for collecting light from said source and directing it to a source image in a focal plane, optical means including a relay lens for collecting divergent light from said source image and directing it toward a focus, means for supporting a photographic transparency forwardly of said relay lens, to be illuminated thereby, a projection lens whose entrance pupil receives said directed light and which forms a real, inverted image of said transparency, to a predetermined scale, in front thereof, and a neutral density filter spaced between said relay lens and said source image, the transmission characteristic of said filter increasing radially outward from its center toward its periphery in a predetermined manner compensating for progressive radially outward decrease in intensity tending to occur in the divergent light between said source image and said relay lens.
Claim 3
Dependent Claim
20 words
The subject matter of claim 1, wherein said neutral density filter is arranged for adjustment movement in a longitudinal direction.
Claim 4
Dependent Claim
62 words
The subject matter of claim 2, including a fly''s eye light integrator with a first lenticular matrix in said focal plane, and a second lenticular matrix just beyond said focal plane, the lenticules of said second matrix being arranged to form magnified, superimposed images of illuminated lenticules of the first matrix on said transparency on the opposite side of said relay lens.
Claim 5
Dependent Claim
16 words
The subject matter of claim 3, including an aperture plate in front of said light integrator.
Claim 6
Dependent Claim
36 words
The subject matter of claim 4, wherein said relay lens has an image to object ratio, from the aperture in said aperture plate to the entrance pupil of said projection lens, of substantially one to one.
Claim 7
Dependent Claim
57 words
The subject matter of claim 4, wherein the aperture of said aperture plate and the entrance pupil of said projection lens are of such relative size and distance ratio from said relay lens that the cone of light entering the entrance pupil of the projection lens has an area of not over 50% of said entrance pupil.
Claim 8
Dependent Claim
18 words
The subject matter of claim 4, including an adjustable iris diaphragm at said aperture in said aperture plate.
References Cited (Backward Citations)
US3536403A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-24 | 1979-05-26 | 1979-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-24 | 1983-05-26 | 1983-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-24 | 1987-05-26 | 1987-11-25 | $7700.00 | Window Closed / Lapsed |