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. 24, 2001
Filed:
Feb. 14, 2000
Hiroyuki Mukaiyama, Nagano, JP;
Akira Komatsu, Nagano, JP;
Seiko Epson Corporation, Tokyo, JP;
Abstract
An additional aspherical surface amount is defined by a sum of the optimum amount at a distance portion and the optimum amount at a near portion on a progressive refractive surface. Assuming that the ratio is taken as &agr;:&bgr;, the additional aspherical surface amount is added to the progressive refractive surface in such a manner that &agr; and &bgr; satisfy a relationship of &agr;+&bgr;=1. With this configuration, in the case where an aspherical shape is added to a progressive power lens for correcting visual acuity for the purpose of improving the optical performance and thinning the lens, the optimum aspherical shape can be given not only to a region along a main meridian line but also to the whole of the progressive refractive surface.