Bausch-lomb Incorporated

Other

Kenneth L Opdyke

William J Appleton

Jeffrey M Vandewinckel

George L Wickes

Richard J Fleenor

An improved method for forming plastic molds for casting articles having an optical surface such as contact lenses employs a plastic tool having an optically smooth surface.

Method of making plastic molds

Apparatus for making plastic molds

Method of making plastic molds for molding contact lenses

A target surface is photoablated by a laser beam by the steps of (a) directing a beam of pulsed UV radiation at a bisecting line on the target surface; (b) scanning the beam in a direction away from the bisecting line to a first edge of the target surface, (c) rotating the target 180 degrees, (d) returning the beam to the bisecting line on the target surface, (e) scanning the beam in a direction away from the bisecting line to the edge opposing the first edge of the target surface; and repeating steps (c), (d) and (e) such that the entire target surface is scanned. This scanning process simultaneously clears away deposited debris and avoids subsequent debris accumulation during the photoablation process.

Scanning technique for laser ablation

Improved methods of modifying target surfaces through ablation are disclosed resulting in a reduction of debris redeposition on the target surface.

An improved method for generating a toric surface on a molding tool for forming contact lens molds comprises:

Method of generating a toric surface on a molding tool

Improved methods for modifying target surfaces through ablation which result in a reduction of ablation debris redeposition on the target surface are disclosed.

An improved method for generating a toric surface on a molding tool for forming contact lens molds comprises: providing a tool which comprises an elongated body and a molding portion at one end of the tool, wherein the molding portion comprises a surface which is substantially spherical; applying a force to the elongated body so as to distort the spherical surface of the molding portion; machining a substantially spherical curve in the distorted surface while maintaining the applied force; and releasing the applied force, wherein the spherically cut surface assumes a toric shape upon release of the applied force.

Growing community of inventors

Fairport, NY, United States of America

Kenneth L Opdyke