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. 28, 1982
Filed:
Dec. 07, 1981
Applicant:
Inventors:
Assignee:
Corning Glass Works, Corning, NY (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C03C / ;
U.S. Cl.
CPC ...
501 74 ; 501903 ;
Abstract
The present invention is drawn to glasses suitable for the fabrication of segments or buttons for multifocal ophthalmic lenses. The inventive glasses have refractive indices ranging between about 1.745-1.771, an Abbe number greater than 29 for a refractive index of 1.771 and greater than 31 for a refractive index of 1.745, a softening point between about 640.degree.-700.degree. C., a coefficient of thermal expansion (25.degree.-300.degree. C.) between about 90-98.times.10.sup.-7 /.degree.C., and satisfactory chemical durability. The glasses consist essentially, expressed in terms of weight percent on the oxide basis, of