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:
Dec. 10, 1996
Filed:
Jul. 07, 1995
Edward H Phillips, Warren, NJ (US);
Phillips Lens Co., Inc., Middlesex, NJ (US);
Abstract
A monocentric seamless bifocal lens is manufactured by obtaining a lens blank having concentric top and bottom spherical surfaces, and grinding the bottom surface to form a major segment having one spherical radius and a minor segment having a second spherical radius. The lens is then placed on a block having two spherical surface portions whose shape conforms to the shape of the major segment, but differs from the shape of the minor segment. The block also has a slight dihedral angle, so that a space remains between the block and at least part of the minor segment. As it rests on the block, the lens is heated so that it sags under its own weight until its bottom surface assumes the shape of the block, and the radius of curvature of the upper surface becomes non-uniform. Finally the bottom surface of the lens is ground and polished to a uniform spherical radius.