US3915547A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Objective lens system
Assignee: United States Department of the Army
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Filing: 1974-10-29
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Granted: 1975-10-28
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Expires: 1994-10-29
Abstract
Abstract A refractive lens system in which all the operative lens surfaces are spherical, and which is exceedingly well corrected for the visible and near infrared spectral ranges over a wide field of view so that it matches both the spectral response required and the flat photocathode of an image intensifier tube.
Inventors
- 👤 Wright H Scidmore
- 👤 Robert P O'shaughnessy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 03:26
CPC Classifications
G; G02; G02B; G02B13/00; G02B13/14; G02B13/02; G02B27/00; G02B27/0025
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
202 words
An objective lens system comprising a plurality of lens members, said lens members arranged on the optical axis in the order as named below and comprising a doublet lens having a focal length f1, a triplet lens spaced from said doublet lens and having a focal length f2, a biconcave lens having a focal length f3 and abutting said triplet lens, a biconvex lens spaced from said biconcave lens and having a focal length f4, and a meniscus field flattener lens spaced from said biconvex lens and having a focal length f5 , and wherein a majority of the operative surfaces of the totality of said lenses have numerically equal radii of curvature, the focal lengths have the following comparative values: F focal length of lens system f1 (> ) is greater than F and is positive, f2 (> ) is greater than F and is positive, f3 (< ) is less than F and is negative, f4 (< ) is less than F and is positive, f5 (< ) is less than F and is negative, and said objective lens system is corrected for the visible and near infrared spectral ranges over a field of view in excess of approximately 7*.
Claim 2
Dependent Claim
202 words
An objective lens system comprising a plurality of lens members, said lens members arranged on the optical axis in the order as named below and comprising a doublet lens having a focal length f1, a triplet lens spaced from said doublet lens and having a focal length f2, a biconcave lens having a focal length f3 and abutting said triplet lens, a biconvex lens spaced from said biconcave lens and having a focal length f4, and a meniscus field flattener lens spaced from said biconvex lens and having a focal length f5 , and wherein a majority of the operative surfaces of the totality of said lenses have numerically equal radii of curvature, the focal lengths have the following comparative values: F focal length of lens system f1 (> ) is greater than F and is positive, f2 (> ) is greater than F and is positive, f3 (< ) is less than F and is negative, f4 (< ) is less than F and is positive, f5 (< ) is less than F and is negative, and said objective lens system is corrected for the visible and near infrared spectral ranges over a field of view in excess of approximately 7*.
Claim 3
Dependent Claim
60 words
A lens system as defined in claim 1 wherein said doublet lens is composed of a biconvex lens and a concave-plano lens, said triplet lens is composed of a biconvex lens, a double-concave lens, and a convex-plano lens, and the focal lengths have the following values, in inches: F 7.796 f1 12.224 f2 12.597 f3 -5.963 f4 6.538 f5 -6.646
Claim 4
Dependent Claim
18 words
A lens system according to claim 1 wherein the operative surfaces of all of said lenses are spherical.
Claim 5
Dependent Claim
20 words
A lens system according to claim 3 which is corrected for a spectral range of approximately 0.45 to 1.0 micron.
Claim 6
Dependent Claim
34 words
A refractive objective lens system having a focal plane FP and eight lens elements whose characteristics and relative spacing on the optical axis are substantially as shown by the data in the following table:
Claim 7
Dependent Claim
34 words
A refractive objective lens system having a focal plane FP and eight lens elements whose characteristics and relative spacing on the optical axis are substantially as shown by the data in the following table:
Claim 8
Dependent Claim
30 words
A lens system as defined in claim 4 characterized further by the provision of means between said biconvex lens and said meniscus field flattener lens for folding the optical path.
Claim 9
Dependent Claim
23 words
A lens system according to claim 4 which is corrected for the S20ER response and the flat photocathode of an image intensifier tube.
References Cited (Backward Citations)
US2600805A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-27 | 1979-04-28 | 1979-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-27 | 1983-04-28 | 1983-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-27 | 1987-04-28 | 1987-10-28 | $7700.00 | Window Closed / Lapsed |