Process and holder for production of spectacles lens - has holder in three parts enabling lens blank to be completely processed without re-mounting

摘要

Spectacle lenses are stocked as circular blanks which are finished on one side. The remaining side is finished and the edge ground to the required profile against an optician's specification. The blank is mounted in a holder, permitting finishing of the remaining lens surface and production of the edge profile without the need for remounting of the lens between operations. The finished side (31) of the lens blank is fastened by adhesive film (2) to a holder consisting of a central part (12) which has to surrounding semi-circular rings (11',11") secured to it by bridge pieces (13). The method of holding permits regrinding of the lens edge followed by finishing of the lens surface to prescription and edge polishing. ADVANTAGE - Method lends itself to NC controlled processing and optimisation of lens critical thickness. Rigid support to lens. Reduced production cost.