Method for computing a progressive spectacle lens and methods for manufacturing a spectacle lens of this kind

US6832834B2 · kind B2 · utility

Assignee

• RODENSTOCK GMBH · DE

Inventors

• Walter Haimerl · Munich, DE
• Herbert Pfeiffer · Munich, DE
• Gregor Esser · Munich, DE
• Helmut Altheimer · Munich, DE

Key dates

• Filing date: Oct 25, 2002
• Grant date: Dec 21, 2004
• Expiry date: Dec 11, 2022

Classification

• Technology area (CPC G): Physics
• CPC primary: G02C7/061
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A method for computing a spectacle lens, which includes a region (distance portion) designed for viewing at large distances and in particular “to infinity”, a region (near portion) designed for viewing at short distances and in particular “reading distances,” and a progressive zone disposed between the distance portion and the near portion, in which the power of the spectacle lens increases, from a value at a distance reference point located in the distance portion to a value at the near reference point located in the near portion along a curve (principal line) veering towards the nose, by an amount designated as addition power. The method includes the steps of stipulating as initial parameters a course of a projection x0(y) of the principal line on an x,y plane, and also properties of the spectacle lens along the principal line whilst taking into account spherical, cylindrical, and possibly also prismatic prescription values and the addition power, as well as an interpupillary distance, and computing with these stipulations at least one strip of second order on a progressive surface of the spectacle lens, stipulating an object-distance function Al(y) which …