Excess polymer ring removal during ophthalmic lens manufacture

Abstract

The present invention includes molds for forming ophtalmic lenses, such as contact lens. In particular, the present invention relates to apparatus, molds and methods for fashioning an ophthalmic lens with a mold assembly that includes two or more mold parts with at least one of the mold parts including a flange surface and a static charge differential between each mold part, including the flange surface.

1 . An apparatus for treating an ophthalmic lens mold assembly:
 wherein the mold assembly comprises a first mold part and a second mold part,   wherein each mold part comprises a lens forming surface and a flange surface,   wherein a lens may be molded between the mold parts by inserting a lens forming material between the lens forming surface of the first mold part and the lens forming surface of the second mold part, as well as between the flange surface of each mold part, and curing the lens forming material, and the apparatus comprises:   a static charge apparatus operative to impart a static charge differential between the lens flange surface of the first mold part and the flange surface of the second mold part.   
     
     
         2 . The apparatus for treating an ophthalmic lens mold of  claim 1  wherein the static charge differential between the first mold part and the second mold part is within a range of about 30 kV. 
     
     
         3 . The apparatus for treating an ophthalmic lens mold of  claim 1  wherein the static charge differential between the first mold part and the second mold part is within a range of about 0. 5 kV and 5.0 kV. 
     
     
         4 . The apparatus for treating an ophthalmic lens mold of  claim 1  wherein the static charge differential between the first mold part and the second mold part is within a range of about 0.05 kV and 0.5 kV. 
     
     
         5 . The apparatus of  claim 1  for treating an ophthalmic lens mold additionally comprising a static charge apparatus operative to discharge static charge present in at least one of the first mold part and the second mold part. 
     
     
         6 . The apparatus of  claim 1  for treating an ophthalmic lens mold additionally comprising an automatic lens inspection system operative to ascertain whether a lens formed comprises an excess polymer ring defect. 
     
     
         7 . The apparatus of  claim 1  for treating an ophthalmic lens mold additionally comprising an automatic lens inspection system operative to: a) ascertain how many of a group of multiple lenses formed comprise an excess polymer ring defects; and b) ascertain whether a static charge differential imparted to each of multiple pairs of respective first mold parts and the second mold parts is sufficient to limit excess polymer ring defects in the group of multiple lenses to less than 5% of the lenses. 
     
     
         8 . The apparatus of  claim 1  for treating an ophthalmic lens mold wherein at least one of the first mold part and the second mold part comprises polypropylene. 
     
     
         9 . The apparatus of  claim 1  for treating an ophthalmic lens mold wherein at least one of the first mold part and the second mold part comprises polystyrene. 
     
     
         10 . The apparatus of  claim 1  for treating an ophthalmic lens mold wherein at least one of the first mold part and the second mold part comprises a cyclic olefin copolymer. 
     
     
         11 - 19 . (canceled) 
     
     
         20 . A mold assembly for forming an ophthalmic lens, the mold assembly comprising:
 a first flange surface comprising a first static charge value; and   a second flange surface comprising a second static charge value;   wherein a differential between the first static charge value and the second static charge value is greater than about 1.0 kV.