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:
Jun. 08, 2010
Filed:
Jun. 22, 2006
Akira Kitani, Tokyo, JP;
Takashi Hatanaka, Tokyo, JP;
Yoshihiro Kikuchi, Tokyo, JP;
Hoya Corporation, Tokyo, JP;
Abstract
There is provided a group of bi-aspherical type progressive-power lenses for which the processing costs are reduced. In a bi-aspherical type progressive-power lens(es), the relationships DHf+DHn<DVf+DVn and DHn<DVn or further, DVn−DVf>ADD/2 and DHn−DHf<ADD/2 are satisfied; DHf and DVf are designated respectively as a surface refractive power in a horizontal direction and a surface refractive power in a vertical direction at a far vision power measurement position Fon a first refractive surface that acts as an object-side surface; with DHn and DVn are designated respectively as a surface refractive power in a horizontal direction and a surface refractive power in a vertical direction at a near vision power measurement position Non the first refractive surface; a surface astigmatism component at Fand Nof the first refractive surface is canceled by a second refractive surface of the eye-side surface; and the first and second refractive surfaces are combined to provide a far vision power (Df) and an addition (ADD) on the basis of a prescription; wherein the same first refractive surface is used for at least two or more kinds of different addition power.