Method and device for positioning a lens member on a manufacturing apparatus

Abstract

This relates to a method including: detecting, using an optical sensor, an intrinsic optical feature of a lens member to be positioned on a manufacturing apparatus configured to apply an optical lens manufacturing operation to the lens member; and determining, using a processing unit, the position or orientation of the lens member in a framework of the manufacturing apparatus based on the intrinsic optical feature. The method can be used to position and block a lens member, i.e. a lens blank or a finished lens, on any type of manufacturing apparatus used for the manufacture of an optical lens. The intrinsic optical features have not been intentionally etched or engraved onto the lens member for the specific purpose of determining the position or orientation of the lens member.

1 . A method comprising:
 detecting, using an optical sensor, at least one intrinsic optical feature of a lens member to be positioned on a manufacturing apparatus configured to apply an optical lens manufacturing operation to said lens member; and   determining, using a processing unit, the position or orientation of the lens member in a framework of the manufacturing apparatus based on said at least one intrinsic optical feature.   
     
     
         2 . The method of  claim 1 , further comprising:
 providing a desired position or orientation of the lens member in the framework of the manufacturing apparatus;   estimating a difference between the desired position and the determined position of the lens member or between the desired orientation and the determined orientation of the lens member; and   adjusting the position or orientation of the lens member on the manufacturing apparatus by moving the lens member translationally from the determined position or rotationally from the determined orientation of the lens member in order to compensate said difference.   
     
     
         3 . The method of  claim 2 , further comprising blocking the lens member on the manufacturing apparatus in the adjusted position or orientation by using blocking means. 
     
     
         4 . The method of  claim 1 , wherein the position of the lens member in the framework of the manufacturing apparatus is characterized by the location of a reference positioning point in the framework of the manufacturing apparatus. 
     
     
         5 . The method of  claim 4 , said at least one intrinsic optical feature including a curvature distribution, wherein the curvature distribution is detected by acquiring, using an image sensor, an image of the lens member, and wherein the position of the lens member in the framework of the manufacturing apparatus is determined as follows:
 providing a theoretical surface characterized by a desired curvature distribution and a location of the reference positioning point on said theoretical surface;   applying a curvature mapping function to the acquired image by the processing unit to generate a map of the curvature distribution of the lens member; and   comparing the desired curvature distribution and the generated map of the curvature distribution of the lens member to determine, based on the location of the reference positioning point on the theoretical surface, the location of the reference positioning point of the lens member in the framework of the manufacturing apparatus.   
     
     
         6 . The method of  claim 1 , said at least one intrinsic optical feature including several distinct characteristics forming a pattern, wherein said distinct characteristics are detected by acquiring, using an image sensor, an image of said lens member, and wherein the position or orientation of the lens member in the framework of the manufacturing apparatus is determined as follows:
 processing, using the processing unit, the acquired image to find the location of a plurality of distinct characteristics; and   deducing therefrom the position or orientation of the lens member in the framework of the manufacturing apparatus.   
     
     
         7 . The method of  claim 6 , wherein the processing of the acquired image comprises the positioning of a predetermined geometrical figure on the acquired image so that said predetermined geometrical figure passes through the plurality of found distinct characteristics, and wherein the position or orientation of the lens member in the framework of the manufacturing apparatus is deduced respectively from the position or orientation of said geometrical figure on the processed image. 
     
     
         8 . The method of  claim 1 , said at least one intrinsic optical feature being a rotation variant of the lens member, wherein the orientation of the lens member in the framework of the manufacturing apparatus is determined on the basis of said rotation variant. 
     
     
         9 . The method of  claim 8 , said at least one intrinsic optical feature including a polarization axis, wherein the polarization axis is detected as follows:
 determining a polarization of a light ray incident on the lens member;   determining a polarization of said light ray after refraction by the lens member; and   deducing therefrom the polarization axis of the lens member by comparing the polarization of said light ray before and after refraction;   wherein the orientation of the lens member in the framework of the manufacturing apparatus is determined on the basis of the polarization axis.   
     
     
         10 . The method of  claims 8 , said at least one intrinsic optical feature including a tint gradient, wherein the tint gradient is detected by acquiring, using an image sensor, an image of a surface of said lens member, and wherein the orientation of the lens member in the framework of the manufacturing apparatus is determined as follows:
 providing a predetermined function of variation of the tint on said surface of the lens member;   processing the acquired image to calculate a function characterizing the variation of the tint on said surface of the lens member; and     1  deducing therefrom the orientation of the lens member in the framework of the manufacturing apparatus by comparing the calculated function with the predetermined function.   
     
     
         11 . The method of  claim 8 , said at least one intrinsic optical feature including a cylinder axis, wherein the cylinder axis is detected as follows:
 placing a pattern image in front of the lens member;   acquiring, using an image sensor, a refracted image of the pattern image through the lens member; and   deducing therefrom the cylinder axis of the lens member by comparing the pattern image before refraction with the refracted image of said pattern image;   wherein the orientation of the lens member in the framework of the manufacturing apparatus is determined on the basis of the cylinder axis.   
     
     
         12 . The method of  claim 1 , wherein the lens member comprises at least one optical element, said at least one intrinsic optical feature including an optical function of said at least one optical element for preventing focusing on the retina of an eye of a wearer under standard wearing conditions, so as to reduce the progression of an abnormal refraction of the eye, wherein said optical function is detected by acquiring, using an image sensor, an image of said lens member, and wherein the position or orientation of the lens member in the framework of the manufacturing apparatus is determined as follows:
 processing, using the processing unit, the acquired image to find the location of the at least one optical element; and   deducing therefrom the position or orientation of the lens member in the framework of the manufacturing apparatus.   
     
     
         13 . A manufacturing process of an optical lens from a lens member comprising one or more optical lens manufacturing operations implemented using at least one manufacturing apparatus, wherein at least one optical lens manufacturing operation is performed using the method of  claim 1 . 
     
     
         14 . A non-transitory computer-readable medium on which is stored a computer program comprising instructions for implementing the method of  claim 1 , when said instructions are executed by at least one processor. 
     
     
         15 . A device comprising:
 an optical sensor configured to detect at least one intrinsic optical feature of a lens member to be positioned on a manufacturing apparatus configured to apply an optical lens manufacturing operation to said lens member; and   a processing unit configured to determine the position or orientation of the lens member in a framework of the manufacturing apparatus based on said at least one intrinsic optical feature.   
     
     
         16 . A non-transitory computer-readable medium on which is stored a computer program comprising instructions for implementing the manufacturing process of  claim 13 , when said instructions are executed by at least one processor.