Patent EP0217526A1 successfully refreshed from Google Patents.
EP0217526A1
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Ultra wide angle micrographic lens
Assignee: 3M Co
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Filing: 1986-08-19
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Granted: —
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Expires: 2006-08-19
Abstract
Abstract A wide-angle lens covering a half angle of 33 degrees and capable of being focussed over a range of 7.4X to 30X, with a satisfactory resolution and distortion at 100% diagonal of under 0.2% at all reductions substantially extends the usefulness of such a micrographic lens.
Inventors
- 👤 John J. C/O Minnesota Mining And Simbal
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 06:26
CPC Classifications
G; G02; G02B; G02B13/00; G02B13/06
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
95 words
An ultra-wide angle micrographic lens comprises ten lens elements comprising at least four groups airspaced from one another, characterized by the feature that the first group comprises a pair of airspaced meniscus lens elements of converging power, the second group comprises a cemented doublet and a biconvex singlet, the third group comprises a plano-concave singlet and a cemented doublet, and the fourth group comprises a cemented doublet, an aperture stop is located between the second and third groups, and said lens elements have a ratio of thickness to diameter equal to or exceeding ten percent.
Claim 2
Dependent Claim
95 words
An ultra-wide angle micrographic lens comprises ten lens elements comprising at least four groups airspaced from one another, characterized by the feature that the first group comprises a pair of airspaced meniscus lens elements of converging power, the second group comprises a cemented doublet and a biconvex singlet, the third group comprises a plano-concave singlet and a cemented doublet, and the fourth group comprises a cemented doublet, an aperture stop is located between the second and third groups, and said lens elements have a ratio of thickness to diameter equal to or exceeding ten percent.
Claim 3
Dependent Claim
77 words
An ultra-wide angle micrographic lens according to claim 1 characterized in that said ten lens elements have a half angle of 33 degrees and an effective focal length of 40.44 mm, and said lens having the characteristics of the lens elements and spacial relationship are substantially as follows: wherein the negative.values for the radii indicate a surface convex to the short conjugate and all dimensions are expressed in proportion to the equivalent focal length of the lens.
References Cited (Backward Citations)
FR1274128A
Cited
DE1497536A1
Cited
DE1804888A1
Cited
FR2108105A1
Cited
DE2359156A1
Cited
US3997247A
Cited
US4099850A
Cited
US4116536A
Cited
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