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. 21, 1998
Filed:
Mar. 14, 1997
Gerhard Kelch, Aalen, DE;
Hans Lahres, Aalen-Wasseralfingen, DE;
Konrad Saur, Aalen-Waldhausen, DE;
Helmut Wietschorke, Aalen-Wasseralfingen, DE;
Carl-Zeiss-Stiftung, Heidenheim, DE;
Abstract
A multifocal spectacle lens has two optically effective surfaces with powers in the far reference point from -4.0 dpt to +4.0 dpt in the stronger principal section. The spectacle lens has cylinders from 0.0 dpt to 4.0 dpt and an addition of 1.00 dpt to 3.00 dpt. The multifocal area is at least aspherical and can be differentiated continuously at least twice and is not axial symmetrical. The multifocal surface includes a far vision zone, a near vision zone and a progression zone lying between the near and far vision zones. The lens body is configured to incorporate a plurality of features within an elliptical region on the surface of the lens body extending 50 mm measured horizontally and 40 mm measured vertically from the measurement point. These features are all satisfied together within the elliptical region. One of the features is that the near-reference point is at most 21 mm perpendicularly below the far-reference point and displaced by about 2.5 mm toward the edge. Also, a principal viewing line interconnects the far-vision zone and the near-vision zone and the principal viewing line defines a curve swung toward the edge more or less in dependence upon the dioptric power of the far-vision zone and the addition. A predetermined region is formed in the progression zone on both sides of the principal viewing line wherein astigmatic deviation is less than 0.75 dpt.