Process for controlling the polishing process of an optical element

Abstract

The invention concerns a process for measuring and/or controlling a polishing process of an ophthalmic element ( 1 ) comprising the steps of manufacturing at least two cavities ( 2, 3 ) on the surface of the element to be polished, the depth of the first cavity ( 2 ) being smaller than the depth of the second cavity ( 3 ) operating the polishing process considering the element ( 1 ), in order to check that the first cavity ( 2 ) is suppressed and that the second cavity ( 3 ) is present.

1 . Process for measuring and/or controlling a polishing process of an ophthalmic element comprising the steps of
 manufacturing at least two cavities on the surface of the element to be polished, the depth of the first cavity being smaller than the depth of the second cavity;   operating the polishing process; and   considering the element, in order to check that the first cavity is suppressed and that the second cavity is present.   
     
     
         2 . Process for controlling a polishing process of an ophthalmic element according to  claim 1 , comprising the steps of:
 predetermining the reference value (X) of the depth of the material to be suppressed by polishing;   manufacturing at least two cavities on the surface of the element to be polished, the depth of the first cavity being smaller than said reference value and the depth of the second cavity being greater than said reference value, the difference between the depths of the cavities and said reference value (X) being comprised between 0.5 and 50 microns;   operating the polishing process; and   considering the element, in order to check that the first cavity is suppressed and that the second cavity is present.   
     
     
         3 . Process according to  claim 1 , wherein two sets of cavities are manufactured, the constant depth of the first set being smaller than said reference value and the constant depth of the second set being greater than said reference value. 
     
     
         4 . Process according to  claim 1 , wherein a plurality of cavities is manufactured, with different depths according to a predetermined increment. 
     
     
         5 . Process according to  claim 4 , wherein said pitch is comprised between 0.5 and 10 microns. 
     
     
         6 . Process according to  claim 1 , wherein said cavities are holes disposed according a regular geometric form. 
     
     
         7 . Process for controlling a polishing process of progressive lens or mold to manufacture said progressive lens, according to  claim 1 , wherein said cavities are disposed in a near vision zone of said progressive lens. 
     
     
         8 . Process for controlling a polishing process of progressive lens or mold to manufacture said progressive lens, according to  claim 7 , wherein said cavities are disposed in a far vision zone of said progressive lens. 
     
     
         9 . Process for controlling a polishing process of progressive lens or mold to manufacture said progressive lens, according to  claim 8 , wherein said cavities are disposed in a progression corridor, between said far vision zone and said near vision zone of said progressive lens. 
     
     
         10 . Process according to  claim 1 , wherein said cavities are grooves. 
     
     
         11 . Process for measuring a polishing process of an ophthalmic element ( 1 ) according to  claim 1 , comprising the steps of:
 choosing points on the surface of the element;   manufacturing a plurality of holes near each said point, each hole of each plurality of holes having a different depth with a increment equal to the searched precision;   operating a controlled polishing process; and   considering the element, in order to determine the polished depth at each said point.