US 12,405,486 B2
Method of generating virtual surface data of a progressive addition lens
Cyril Guilloux, Charenton le Pont (FR); Gilles Le Saux, Charenton le Pont (FR); and Olivier Roussel, Charenton le Pont (FR)
Assigned to Essilor International, Charenton-le-Pont (FR)
Appl. No. 17/416,259
Filed by Essilor International, Charenton-le-Pont (FR)
PCT Filed Dec. 9, 2019, PCT No. PCT/EP2019/084255
§ 371(c)(1), (2) Date Jun. 18, 2021,
PCT Pub. No. WO2020/126621, PCT Pub. Date Jun. 25, 2020.
Claims priority of application No. 18306775 (EP), filed on Dec. 20, 2018.
Prior Publication US 2022/0075209 A1, Mar. 10, 2022
Int. Cl. G02C 7/06 (2006.01); G02C 7/02 (2006.01)
CPC G02C 7/068 (2013.01) [G02C 7/028 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A method, comprising:
acquiring prescription data including at least a sphere value, a cylinder value, and an addition value;
generating virtual surface data of a progressive addition lens for a further operation of surfacing of a lens blank, the operation of surfacing being configured to transform the lens blank into a surfaced lens satisfying the prescription data, the generating the virtual surface data comprising:
obtaining a virtual base surface in a virtual base surface database storing at least one virtual progressive base surface so that the virtual base surface is obtained without reference to or reliance upon the prescribed addition value,
processing the selected virtual base surface according to the prescribed addition value to obtain a modified virtual base surface providing at least a part of the prescribed addition value,
selecting a virtual adjusting surface in a virtual adjusting surface database storing a plurality of virtual adjusting surfaces at least on the basis of a value of a parameter relative to the modified virtual base surface, and
combining the modified virtual base surface and the selected virtual adjusting surface to form a virtual progressive adjusted surface;
selecting a semi-finished lens in a semi-finished lens database on the basis of the prescribed sphere value and the prescribed cylinder value, the semi-finished lens having a first surface which is a finished surface and a second surface which is an unfinished surface; and
surfacing the second surface of the semi-finished lens on the basis of the virtual surface data so that the second surface of the semi-finished lens, after the surfacing, corresponds to the virtual progressive adjusted surface, wherein
each virtual progressive base surface stored in the virtual base surface database corresponds to a virtual front progressive surface so that the virtual progressive adjusted surface formed from the combination of the virtual base surface with the virtual adjusting surface is a virtual progressive front surface, and
the method further comprises:
performing a reversing operation to transform the virtual progressive front surface into a virtual reversed progressive adjusted surface;
generating a virtual sphero-toric surface on the basis of the prescribed sphere value, the prescribed cylinder value and the finished front surface of the selected semi-finished lens; and
combining the virtual reversed progressive adjusted surface with the virtual sphero-toric surface to form a final virtual progressive back surface.