Ultraviolet cycling oven for polymerization of contact lenses

Claim 2

An apparatus according to Claim 1 wherein said mold is transparent to ultraviolet radiation, and said source emits ultraviolet radiation.

Claim 3

An apparatus according to Claim 2 wherein said source comprises a plurality of bulbs disposed on said longitudinal axis, wherein each of said bulbs emits ultraviolet radiation, wherein the ultraviolet radiation emitted from regions adjacent the ends of each of said bulbs is of lesser intensity and the ultraviolet radiation emitted from a region between said ends is of greater intensity.

Claim 4

An apparatus according to Claim 3 wherein at least 3 of said bulbs are disposed on said axis.

Claim 5

An apparatus according to Claim 3 wherein said source further comprises a second plurality of said bulbs disposed on a second longitudinal axis parallel to said longitudinal axis.

Claim 6

An apparatus according to Claim 5 wherein at least 3 of said bulbs are disposed on each longitudinal axis.

Claim 7

An apparatus according to Claim 3 wherein the temperature at which said heater maintains said polymerizable composition is in a range above the softening point of said composition.

Claim 8

An apparatus according to Claim 3 wherein the distance between said transport apparatus and said source is adjustable.

Claim 9

An apparatus according to Claim 3 wherein the intensity of the ultraviolet radiation emitted at any point of any given bulb is constant.

Claim 10

An apparatus according to Claim 3 further comprising structure which maintains an atmosphere free of oxygen around said mold while said polymerizable composition is polymerized in said apparatus.

Claim 11

A process for forming a contact lens comprising providing a mold assembly comprising a front mold half and a back mold half which together form a cavity therebetween in the shape and size of a contact lens, the mold cavity further comprising a composition disposed in said cavity which is polymerizable upon exposure thereof to polymerization-initiating radiation, wherein at least one of said mold halves is transparent to said radiation; providing a source of polymerization-initiating radiation, said source having a longitudinal axis, wherein the intensity of said radiation transmitted to a given plane parallel to said axis exhibits maximal values, sufficient to initiate polymerization of said composition, within at least two regions of maximal intensity along said axis and values less than said maximal values in regions of lesser intensity between each adjacent pair of said at least two regions and at each end of said axis, wherein the intensity of said radiation varies smoothly between said maximal and lesser intensities; providing a source of heat to said polymerizable composition in said cavity while said composition is being exposed to said radiation from said source, said heat being sufficient to promote the propagation of said polymerization and to minimize shrinkage of said composition upon polymerization thereof; and exposing said polymerizable composition to radiation from said source while moving said mold assembly relative to said source in said plane along a line equidistant from said longitudinal axis from one end thereof to the other at a distance from said source such that said polymerizable composition is exposed to radiation sufficient to initiate polymerization of said composition at a first initiation rate when said mold assembly is adjacent to said regions of maximal intensity and at a second initiation rate less than said first initiation rate when said mold assembly is adjacent said regions of lesser intensity while controlling the rate of said movement and the amount of heat supplied to said composition from said source of heat so as to cause complete initiation of polymerization of said composition and to cause said composition to polymerize into a body useful as a contact lens.

Claim 12

A process according to Claim 11 further comprising maintaining an oxygen-free atmosphere around said polymerizable composition while irradiating it with said polymerization-inducing radiation.

Claim 13

A process according to Claim 11 further comprising, prior to exposing said polymerizable composition to radiation from said source, irradiating said composition with polymerization-inducing radiation effective to initiate polymerization sufficient to cause said mold halves and said composition to adhere together.

Claim 14

A process according to Claim 13 further comprising maintaining an oxygen-free atmosphere around said polymerizable composition while exposing it to said radiation from said source.

Claim 15

A process according to Claim 11 wherein at least one of said mold halves is transparent to ultraviolet radiation, said composition disposed in said cavity is polymerizable upon exposure to ultraviolet radiation, and said polymerization-initiating radiation is ultraviolet radiation.

Claim 16

A process according to Claim 15 further comprising, prior to exposing said polymerizable composition to radiation from said source, irradiating said composition with ultraviolet radiation effective to initiate polymerization sufficient to cause said mold halves and said composition to adhere together.

Claim 17

A process according to Claim 15 wherein said source comprises a plurality of bulbs disposed on said longitudinal axis, wherein each of said bulbs emits ultraviolet radiation, wherein the ultraviolet radiation emitted from regions adjacent the ends of each of said bulbs is at a lesser intensity value and the ultraviolet radiation emitted from a region between said ends is at a greater intensity value.

Claim 18

A process according to Claim 17 wherein at least 3 of said bulbs are disposed on said axis.

Claim 19

A process according to Claim 17 wherein said source further comprises a second plurality of said bulbs disposed on a second longitudinal axis parallel to said longitudinal axis.

Claim 20

A process according to Claim 19 wherein at least 3 of said bulbs are disposed on each longitudinal axis.

Claim 21

A process according to Claim 17 wherein the temperature at which said source of heat maintains said polymerizable composition is in a range above the softening point of said composition.

Claim 22

A process according to Claim 17 wherein the distance between said mold assembly and said source of radiation is adjustable.

Claim 23

A process according to Claim 17 wherein the intensity of the ultraviolet radiation emitted at any point of any given bulb at a given time remains constant.