IN SITU BASE CURVE VERTEX DETECTION AND EMPLOYMENT THEREOF IN CONTACT LENS MANUFACTURE

摘要

An apparatus and method for in situ concave base curve detection which is especially useful in the lathe. The apparatus and method utilize a laser beam (33) and a photo-diode detector (46) to effect a precise detection of the vertex (14) of the concave base curve (15) defined on the rear face of lens blank (16), fixed to an arbor (21). Once a reference point corresponding to the vertex has been established, a shaping tool (54) cuts a curve of predetermined radius on the front face of the lens at a precise lens thickness to provide the desired contact lens.