Method For Polishing an Optical Surface By Means of a Polishing Tool

Abstract

Polishing method comprising a step of receiving a surface to be polished, a configuration step during which the polishing machine is configured, and a polishing step during which the optical surface is polished, wherein the angle of inclination of the pin is between 2° and 20°, the inner cusp point is between −10 mm and 10 mm, the outer cusp point is between R−15 mm and R−5 mm, the speed of advance is between 100 mm/min and 2000 mm/min; the speed of rotation is between 500 rpm and 3000 rpm; and the bearing force is between 50 N and 180 N.

1 . A method for polishing an optical surface by means of a polishing tool, the polishing method comprising:
 a step of receiving a surface, during which an optical surface to be polished is received;   a configuration step, during which the polishing machine comprising a polishing tool is configured; and   a polishing step, during which the optical surface is polished by means of the polishing machine configured during the configuration step,   wherein during the configuration step, the polishing machine is configured in such a way that:
 the angle of inclination (α) of the pin is greater than or equal to 2° and less than or equal to 20°, 
 the inner cusp point is greater than or equal to −10 mm and less than or equal to 10 mm, 
 the outer cusp point is greater than or equal to R−15 mm and less than or equal to R−5 mm, with R being the half-diameter of the circle circumscribed on the surface to be polished, expressed in millimetres; 
 the speed of advance is greater than or equal to 100 mm/min and less than or equal to 2000 mm/min; 
 the speed of rotation of the surface to be polished is greater than or equal to 500 rpm and less than or equal to 3000 rpm; and 
 the bearing force is greater than or equal to 50 N and less than or equal to 180 N. 
   
     
     
         2 . The method according to  claim 1 , wherein the polishing step has a duration greater than or equal to 20 seconds and less than or equal to 130 seconds. 
     
     
         3 . The method according to  claim 1 , wherein the polishing step has a duration independent of the surface properties and the material of the optical surface to be polished, the duration of said polishing step being greater than or equal to 60 seconds and less than or equal to 80 seconds. 
     
     
         4 . The method according to  claim 1 , wherein the polishing tool comprises:
 a rigid support having a transversal end surface and belonging to a base having a flexible flange surrounding the support;   an elastically compressible interface which is applied against and covers the end surface of the flexible flange located on the same side as said end surface;   a flexible pad which is adapted to be applied against the optical surface and which is applied against and at least partly covers the interface opposite and in line with said end surface, the pad having a so-called central part which lies in line with said end surface and a so-called peripheral part which lies transversely beyond the end surface; and   elastic returning means connecting the peripheral part to the support, the combination of the peripheral part and the returning means forming a means for stabilization of the tool during the polishing.   
     
     
         5 . The method according to  claim 1 , wherein the angle of inclination of the pin is greater than or equal to 5° and less than or equal to 15°. 
     
     
         6 . The method according to  claim 1 , wherein the inner cusp point is non-zero and greater than or equal to −5 mm and less than or equal to 5 mm. 
     
     
         7 . The method according to  claim 1 , wherein the outer cusp point is greater than or equal to R−12 mm and less than or equal to R−8 mm. 
     
     
         8 . The method according to  claim 1 , wherein the speed of advance is greater than or equal to 500 mm/min and less than or equal to 1500 mm/min. 
     
     
         9 . The method according to  claim 1 , wherein the speed of rotation is greater than or equal to 900 rpm and less than or equal to 2100 rpm. 
     
     
         10 . The method according to  claim 1 , wherein the bearing force is greater than or equal to 80 N and less than or equal to 150 N. 
     
     
         11 . A method for surfacing an optical surface, comprising:
 a data reception step, during which surface data defining the optical properties of a surface are received,   a step of machining the optical surface, during which the optical surface is machined as a function of the surface data, and   a polishing step, during which the machined surface is polished by means of a polishing method according to  claim 1 .   
     
     
         12 . A computer program product comprising a series of instructions which, when loaded in a computer, leads to the computer carrying out the steps of the method according to  claim 1 . 
     
     
         13 . A polishing machine configured for carrying out the steps of the method according to  claim 1 .