Systems and methods for producing contact lenses from a polymerizable composition

• US 20070035050A1
• Filed: 08/09/2005
• Published: 02/15/2007
• Est. Priority Date: 08/09/2005
• Status: Active Grant

• Current Assignee: Aisin AW Company Limited (Aisin Corp.), Coopervision International Limited (The Cooper Cos., Inc.)
• Original Assignee: CooperVision Incorporated (The Cooper Cos., Inc.)
• Inventors: Rogers, Richard
• Granted Patent: US 7,785,092 B2
• Time in Patent Office: Days
• US Class Current: 264/1.320
• CPC Class Codes: B29D 11/00134 Curing of the contact lens material
• CPC Class Codes: Y10S 425/808 Lens mold

Abstract

Systems and methods of manufacturing ophthalmic lenses, for example, soft, extended wear silicone hydrogel contact lenses, are provided. The systems generally include a housing having an illuminated chamber, a carrier, for example a tray, movable in the illuminated chamber from an inlet portion to an outlet portion of the housing, and the tray configured to carry a plurality of contact lens molds. Polymerizing light energy is provided, for example, by multiple fluorescent lamps, to the molds at an intensity effective to at least initiate polymerization of a monomer composition located in each of the molds. The light may be illuminated onto two opposing sides of each mold. In some cases, the intensity of the light provided to one side of the mold may be different to the light intensity provided to the opposing side of the mold. In addition, the system may include features that are effective to provide for an instantaneous start and an instantaneous end to the light induced cure of the monomer in the molds. The system may include DALI protocol based technology for controlling the fluorescent lamps.

Claims

1. A system for producing contact lenses from a polymerizable composition, the system comprising:

a housing defining a chamber and having an inlet portion and an outlet portion;

a carrier movable in the chamber between the inlet portion and the outlet portion, the carrier being configured to carry a plurality of molds containing a polymerizable composition;

a first light source located in the housing spaced apart from and generally facing a first side of the carrier for providing light effective to facilitate polymerization of the polymerizable composition in the molds;

a second light source located in the housing spaced apart from and generally facing a substantially opposing second side of the carrier for providing light effective to facilitate polymerization of the polymerizable composition in the molds; and

the carrier being configured to allow the plurality of molds carried by the carrier to be exposed to light from both the first light source and the second light source.

2. The system of claim 1 wherein the carrier includes a plurality of through holes, each of the through holes being sized and configured to allow a mold carried by the carrier to be seated therein.

3. The system of claim 1 further comprising a conveyor assembly structured to move the carrier through the chamber.

4. The system of claim 1 which further comprises an optical surface located in the housing and effective in at least one of diffusing light, reflecting light and absorbing light to enhance consistency of the light provided to the molds carried by the carrier.

5. The system of claim 1 wherein the inlet portion of the housing is structured to shield the carrier from receiving effective light when the carrier is located in the inlet portion.

6. The system of claim 5 wherein the inlet portion comprises an enclosable vestibule.

7. The system of claim 1 structured to provide light to the carrier at an intensity in a range of about 100 μ

W/cm² and about 2000 μ

W/cm² when measured using a Spectronics digital radiometer DRC-100X with DIX 365A sensor.

15. The system of claim 5 wherein the inlet portion comprises an enclosable vestibule.

16. The system of claim 1 structured to provide light to the carrier at an intensity in a range of about 100 μ

W/cm² and about 2000 μ

W/cm² when measured using a Spectronics digital radiometer DRC-100X with DIX 365A sensor.

8. A system for producing contact lenses from a polymerizable composition, the system comprising:

a housing defining a chamber having an inlet portion and an outlet portion;

a carrier sized to be received in the housing chamber, the carrier being configured to carry a plurality of molds containing a polymerizable composition useful in forming a contact lens;

a light assembly located in the housing and structured to provide light effective to facilitate polymerization of the polymerizable composition in the molds; and

the system being structured to provide substantially uniform light to the molds while the carrier is moved between the inlet portion and the outlet portion.

9. The system of claim 8 further comprising a conveyor assembly structured to move the carrier through the chamber.

10. The system of claim 8 structured to provide at least one of substantially instantaneous initiation and substantially instantaneous termination of effective light provided to the molds upon the molds entering and exiting the housing chamber.

11. The system of claim 8 wherein the carrier includes a plurality of through holes, each of the through holes being sized and configured to allow a mold carried by the carrier to be seated therein to be exposed to light to which two substantially opposing sides of the carrier is exposed.

12. The system of claim 9 wherein the conveyor assembly comprises a mechanism structured to automatically move the carrier into the chamber and out of the chamber.

13. The system of claim 8 which further comprises an optical surface located in the housing and effective in at least one of diffusing light, reflecting light and absorbing light to enhance consistency of the light provided to the molds carried by the carrier.

14. The system of claim 8 wherein the inlet portion of the housing is structured to shield the carrier from receiving effective light when the carrier is located in the inlet portion.

17. A method for producing contact lenses from a polymerizable composition, the method comprising:

providing a carrier carrying a plurality of molds wherein each mold contains a polymerizable composition;

providing a chamber containing a light source providing light to the chamber effective to facilitate polymerization of the polymerizable composition;

exposing the molds in the carrier to the light in the chamber; and

during the step of exposing, using DALI protocol-based technology to monitor the light source.

18. The method of claim 17 wherein the light source comprises a plurality of UV lamps mounted in the chamber.

19. The method of claim 17 further including the step of collecting light intensity data using a sensor carried on the carrier.

20. The method of claim 17 further including the step of collecting light intensity data using a plurality of sensors carried on different regions of the carrier.