APPARATUS FOR AND METHOD OF CONTROLLING LATHED CONTACT LENS THICKNESS

摘要

APPARATUS FOR AND METHOD OF CONTROLLING LATHED CONTACT LENS THICKNESS A device for and a method of controlling the thickness of a contact lens produced on an automatic and computerized numerically controlled (CNC) laths is disclosed. A sensor control device is incorporated on a lens lathing machine for engaging the front surface of a lens button upon which the convex surface of the contact lens is to be machine lathed. Immediately upon contact between the sensor and the front surface, the sensor provides for breaking an electrical circuit in the lathe controller providing for automatic position registration of the lens button front surface relative to the cutting tool and its pivot point, and a lens of desired center thickness and power curve radius is subsequently generated. Close tolerances and high repeatabllity are demonstrated in contact lenses lathed generated by these principles. BACKGROUND OF THE INVENTION 1. Field of the invention: This invention relates to apparatus and techniques for improving the automatic generation of lathed contact lenses and more particularly for controlling the center thickness of lathed lenses.