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:
Apr. 02, 1991
Filed:
Mar. 16, 1990
Isao Ishibai, Tokyo, JP;
Hitonobu Otsu, Tokyo, JP;
Hoya Corporation, Tokyo, JP;
Abstract
In an aspherical lens element which has an optical axis, a focal length f, a thickness D along the optical axis, and first and second aspherical convex surfaces defined by first and second predetermined formulae represented as functions of first and second radii r.sub.1 and r.sub.2 of curvature at apexes of the first and the second aspherical convex surfaces and first and second coefficients k.sub.1 and k.sub.2 of cones, the aspherical lens element is formed by a low dispersion glass material which has a refractive index n and an Abbe number .nu. specified by:
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile