Printing apparatus for making colored contact lenses
View Patent ↗A printing station for producing a layer of coloring for a contact lens, comprising a transport system to carry and transport a molding tool which comprises at least one contact lens forming mold, a pad unit comprising at least one pad, and a blade unit suitable to carry and ink a cliché with an ink. When in use the pad transfers an inked image from the cliché to the contact lens forming mold. The printing station further at least partially cures the inked image after it has been transferred to the mold and cleans the pad.
1. A printing station for producing a layer of coloring for a contact lens, comprising:
a transport system to carry and transport a molding tool which comprises at least one contact lens forming mold;
a pad unit comprising at least one pad for printing an ink image onto the contact lens forming mold;
wherein the pad comprises a depression corresponding to the optical visual zone of a contact lens such that said depression does not contact ink during printing;
a blade unit suitable to carry and ink a cliché with an ink;
wherein when in use the pad transfers an inked image from the clichéto the contact lens forming mold; and
curing means to at least partially cure the inked image after it has been transferred to the mold.
2. A printing station of claim 1 wherein the blade unit comprises an ink supply and a doctoring blade.
3. A printing station of claim 1 wherein one cliché is used for printing more than one color.
4. A printing station of claim 1 wherein the transport system alternates stationary positron and movement within the printing station.
5. A printing station of claim 4 wherein each mold is in one stationary position for no longer than 30 seconds.
6. A printing station of claim 1 , wherein the ink is a water-based ink which has a viscosity greater than 100 centipoise (cps), and comprises at least one colorant, a water-soluble binder polymer having ethylenically unsaturated groups, an initiator, and a surfactant.