The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 02, 1996
Filed:
Nov. 30, 1993
John J Simbal, Woodbury, MN (US);
Minnesota Mining and Manufacturing Company, St. Paul, MN (US);
Abstract
A stepless zoom lens useful in micrographic applications providing stepless magnfications from 6.8x to 32x, a zoom ratio exceeding 4.7 to 1. Fourteen elements are arranged in three groups. An object to image distance of 1,750 millimeters is maintained. The first group consists of a cemented doublet air spaced from a single meniscus element, for a total of three elements in the group. The second group consists of a meniscus element air spaced from a cemented doublet, which is in turn air spaced from a second meniscus element, a total of four elements in the group. The third group consists of a biconvex element air spaced from a cemented doublet, followed in order by an air space, a meniscus, an air space and a final doublet, for a total of seven elements in the group.