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:
Feb. 13, 2001
Filed:
Oct. 16, 1998
Sandrine Francois, Saint Jacques, FR;
Bernard Bourdoncle, Paris, FR;
Essilor International, Charenton Cedex, FR;
Abstract
The invention relates to a pair of progressive ophthalmic spectacle lenses; each lens has an aspherical surface with a far vision zone, an intermediate vision zone and a near vision zone, and good monocular and binocular foveal vision along the principal meridian. At each point of the aspherical surface there is a mean sphere which is proportional to the half sum of the maximum and minimum radii of curvature expressed in meters, and to the refractive index of the lens material. The invention suggests reducing, for a given direction of sight, the absolute value of the difference between a binocularity parameter for two points in the object space. The binocularity parameter is defined for a point in the object space as the relative difference &Dgr;S of the mean sphere for the points of the aspherical surface of the right and left lenses through which the wearer sees said point.