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:
Sep. 19, 2000
Filed:
Oct. 05, 1998
Werner Fiala, Vienna, AT;
Johann Pingitzer, Schattendorf, AT;
Bifocon Optics GmbH, Vienna, AT;
Abstract
A multifocal diffractive lens includes at least two annular zone lenses. Provided between adjacent annular zone lenses is an optical step. Each annular zone lens exhibits a refractive power profile D.sub.g,i (r) wherein i is any i-th annular zone lens and r is the distance between an axis of the diffractive lens and a point on a back surface of the lens. The lens is further characterized in that an average power of zones i,j . . . are given by D.sub.av,i, D.sub.avj . . . respectively, and optical path lengths of light rays extending from an object point to a conjugated image point are different by the optical step for light rays transmitting through adjacent annular zone lenses. The annular zone lenses are shaped and positioned such that all of the average refractive powers D.sub.av,i, D.sub.avj . . . are substantially equal to a single value, D.sub.av.