Patent TW-401522-B (TW)
Title: Method and apparatus for assembling a lens-forming device and gasket therefor
Inventor: SU KAI C
IPC: G02B7/00
Filed: 1998-03-24
Granted: 2000-08-11
Abstract: The present invention encompasses a gasket defining an axially extending bore therethrough, a front mold having an edge circumscribing the front mold, wherein the edge is of a size to be complementarily received within at least a portion of the bore of the gasket so that the edge and the bore form a seal therebetween, and a rear mold having a rim circumscribing the rear mold, wherein the rim is sized to be complementarily received within at least a portion of the bore so that the rim and the bore form a seal therebetween. When the front mold and the rear mold are both disposed within the bore of the gasket, a volume is formed between the back surface of the front mold and the front surface of the rear mold and the interior surface of the gasket. A selected one of the front mold or the rear mold is axially and slidably movable within the bore relative to the other mold disposed within the bore to a desired one of a plurality of axial separation distances between the molds, whereby the volume is different for each separation distance. The different volumes correspond to different lens powers, so that the gasket of the present invention can form different lenses. The present invention includes an apparatus and method for assembling a lens-forming structure having the front mold, the rear mold, and the gasket comprising a collet for supporting the gasket so that at least one of the front mold or the rear mold are insertable into the bore thereof, a robotic arm for inserting the front mold into the bore of the gasket, and a piston for inserting the rear mold into the bore of the gasket. The piston axially moves within the bore of the gasket a selected one of the front mold or the rear mold relative to the other mold to a desired one of a plurality of axial separation distances between the molds. The present invention also includes an apparatus and method for forming a lens using the structure comprising a piston for axially moving within the bore of the gasket a selected one of the front mold or the rear mold relative to the other mold to a desired one of a plurality of axial separation distances between the molds. A needle also preferably also communicates with the bore of the gasket between the molds to provide fluid communication between the outer surface of the gasket and the bore to facilitate axial movement of the molds relative to each other. Another needle is used for injecting a desired amount of a lens-forming fluid into the bore of the gasket intermediate the front and rear molds, in which the fluid is cured to form the lens. Still another aspect of the present invention is a method for curing the lens-forming fluid, comprising exposing the lens-forming fluid to an ultra-violet light, wherein the exposure time is between twenty seconds and thirty minutes, which can completely cure the fluid. The exposure can occur by placing the lens-forming fluid intermediate a plurality of ultraviolet light sources, in which the intensity of the ultraviolet light is at least 1.2x10<-2> watts per square centimeter at a wavelength of 350 nanometers.