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:
Jul. 01, 1997
Filed:
Mar. 27, 1995
Seiko Epson Corporation, Tokyo-to, JP;
Abstract
A variable focus type eyesight correcting apparatus in which a plurality of optical lenses are superimposed on each other and in which a refracting power is changed by relatively sliding the lenses in the direction of the superimposed surfaces, achieves a reduction of astigmatism, assurance of uniform refracting power, prevention of diffused reflection, which could be caused if a plurality of refractive surfaces are present, and miniaturization of lens system. When a change of astigmatism in each constituent lens in the variable focus type eyesight correcting apparatus is expressed by contours spaced at intervals of arbitrary diopter, the contours are arranged to be substantially linear and parallel to the principal meridian. The astigmatism becomes absent and the refracting power becomes constant in the region where the eyeglass lenses of the present invention are superimposed on each other, whereby the lenses of the invention can have the optical performance identical to that of single focal lens.