Series for progressive spectacle lenses

US5880810A · kind A · utility

Assignee

• Optische Werke G. Rodenstock · DE

Inventors

• Helmut Altheimer · Munich, DE
• Rudolf Barth · Hohenkirchen, DE
• Peter Baumbach · Hersbruck, DE
• Jochen Brosig · Grünwald, DE
• Gregor Esser · Munich, DE
• Gunther Guilino · Munich, DE
• Christine Meixner · Munich, DE
• Herbert Pfeiffer · Munich, DE
• Manfred Rohrbach · Hebertshausen, DE

Key dates

• Filing date: Jun 28, 1996
• Grant date: Mar 9, 1999
• Expiry date: Jun 28, 2016

Classification

• Technology area (CPC G): Physics
• CPC primary: G02C2202/08
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A series of progressive ophthalmic lenses, each having a varying surface power in a distance part and/or a varying increase in surface power from a distance part to a near part, includes a front surface having a continuously varying surface power and an eye-facing surface, principal sections of which have varying powers and at least one of which deviates from a circular form. The lenses have astigmatic power and are distinguished by a deviation (dz) between an apex circle and a sagitta of each principal section, as given by the equation: EQU dz=a.sub.j *r.sup.2 +b.sub.j *r.sup.4 with coefficients EQU .vertline.a.sub.j .vertline..ltoreq.2*10.sup.-4 mm.sup.-1 EQU .vertline.b.sub.j .vertline..ltoreq.1*10.sup.-6 mm.sup.-3 and where coefficients a.sub.j2 and b.sub.j2 are yielded by the following functionals: EQU a.sub.j =f.sub.j1 (sph,zyl)=a.sub.j1 (sph)+b.sub.j1 (sph)*zyl EQU b.sub.j =f.sub.j2 (sph,zyl)=a.sub.j2 (sph)+b.sub.j2 (sph)*zyl with coefficients a.sub.j2 and b.sub.j2 being a function of a second order.