Novartis AG
Method and device for determining whether or not a single use mold is acceptable

Abstract:

A method for determining whether or not a single use mold is acceptable, comprises providing a closed lens mold (1) comprising two lens mold halves, and having a first and a second optical lens molding surface forming a molding cavity (15) and defining a molding cavity thickness therebetween, providing at least one interferometer (3), each having at least one thickness measurement beam (31), providing a lens mold holder (2), positioning the lens mold (1) such that the thickness measurement beam (31) of the interferometer (3) impinges on the lens mold (1) for measurement of the distance between the two molding surfaces surrounding the molding cavity (15), measuring the thickness profile of the molding cavity (15) with the interferometer (3) on at least three positions of the molding cavity (15) of the lens mold (1), comparing the measured thickness profile with a predetermined thickness profile to determine whether or not the lens mold (1) is acceptable.