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US 5,632,936 AGranted
Method and apparatus for molding ophthalmic lenses using vacuum injection
AssigneeCiba-Geigy Corporation
InventorsKai C. Su, Jack C. White, Hans U. Schlapfer
Life of this patent
Estimating the term…
Abstract
A lens mold cavity is formed and then evacuated via a vacuum channel contained within a mold member. A fluid valve is opened to expose the lens mold cavity to liquid lens material, whereby a vacuum of the lens mold cavity draws the liquid lens material to fill the lens mold cavity. The fluid valve is then closed and the liquid lens material within the lens mold cavity is cured to obtain an opthalmic lens such as a contact lens.
Claims22
A method of making a molded ophthalmic lens comprising:
- forming a lens mold cavity having a configuration conforming to the opthalmic lens to be molded;
- evacuating the lens mold cavity to create a vacuum within the lens mold cavity;
- introducing a liquid lens material into the evacuated lens mold cavity by opening a valve having a valve opening at the lens mold cavity, wherein the vacuum within the lens cavity draws the liquid lens material into the lens mold cavity through the valve opening to fill the lens cavity;
- and,
- curing the lens material within the lens mold cavity to obtain the molded opthalmic lens.
2 more elements
A method of making a molded ophthalmic lens comprising:
- placing a first mold member having one of an optically finished convex or concave surface in contact with a second mold member having one of an optically finished convex or concave surface to form a lens mold cavity having a configuration conforming to the ophthalmic lens to be molded;
- evacuating the lens mold cavity to create a vacuum within the lens mold cavity;
- opening a valve having a valve opening at the lens mold cavity to introduce liquid lens material into the evacuated lens mold cavity, wherein the vacuum within the lens cavity draws the liquid lens material into the lens mold cavity via the valve opening to fill the lens cavity;
- closing the valve after the lens mold cavity is filled with liquid lens material;
- curing the lens material within the lens mold cavity to obtain the molded opthalmic lens.
2 more elements
An apparatus for making a molded ophthalmic lens comprising:
- a first mold member having one of an optically finished convex or concave surface and configured to receive a second mold member having one of an optically finished convex or concave surface so as to define a lens cavity therebetween having a configuration conforming to the ophthalmic lens to be molded;
- a vacuum channel communicating with an area between said first mold member and the second mold member received by said first mold member, said vacuum channel connectable to a vacuum pump for evacuating the area between said first mold member and the second mold member received by said first mold member;
- a fluid channel, in fluid communication with the lens cavity defined between said first mold member and the second mold member received by said first mold member, for containing a liquid lens material;
- and,
- a fluid valve, having a valve opening at said lens cavity, operatively interposed in said fluid channel to control a flow of the liquid lens material drawn by a vacuum into the lens cavity defined between said first mold member and the second mold member received by said first mold member.
2 more elements
Dependencies are inferred from the claim text.