High yield bonding process for manufacturing polycarbonate polarized lenses
View Patent ↗The disclosed technique employs a process for mating polarizing wafers to clear lenses using a high-yield bonding process. A thermoformed polarizing wafer is bonded to a clear lens of similar curvature via a solvent bonding process. In one embodiment, a system includes a translation stage configured to press a first lens to a second, with a solvent therebetween, such that a portion of the first lens initially contacts a portion of the second lens. An alignment fixture holding the second lens conforms to the curvature of the second lens, and a deformable sheet mounted proximate to the alignment fixture flexes in response to the force so that either of the first or second lenses conforms to a curvature of the other, and so that the pressure of the first lens against the second lens presses the solvent radially outward to the perimeter of the second lens to bond the first lens to the second lens.
1. A system for bonding lenses, the system comprising:
a translation stage configured to hold a first lens having a complex curvature, wherein the translation stage is configured to provide a force towards a base with a second lens having a complex curvature such that a portion of the surface of the first lens initially contacts a portion of the surface of the second lens;
an alignment fixture mounted on the base and configured to conform to the curvature of the second lens to hold the second lens;
a dispenser for dispensing a solvent between the lenses; and
a deformable sheet mounted on the base proximate to the alignment fixture, the deformable sheet configured to flex in response to the force so that either of the first or second lenses conforms to a curvature of the other, and so that the pressure of the first lens against the second lens presses the solvent radially outward to the perimeter of second lens to bond the first lens to the second lens, wherein the taut portion is substantially planar when the force is not being applied against the deformable sheet.
2. A system according to claim 1 , wherein the translation stage is further configured to hold the first lens against the second lens such that the first lens bonds to the second lens using the solvent.
3. A system according to claim 1 wherein the portion of the surface of the first lens is the apex of the first lens.
4. A system according to claim 1 wherein the portion of the surface of the second lens is the nadir of the second lens.
5. A system according to claim 1 wherein the surface of the first lens is convex.
6. A system according to claim 1 wherein the surface of the second lens is concave.
7. A system according to claim 1 , wherein the solvent softens the lenses at the molecular depth of their surfaces to bond the first lens to the second lens.
8. A system according to claim 1 , wherein the second lens is substantially thinner than the first lens, and wherein the second lens conforms to the curvature of the first lens.
9. A system according to claim 1 , wherein the dispenser is configured to dispense a solvent vapor between the lenses.
10. A system according to claim 1 , wherein the dispenser is configured to dispense one or more droplets of solvent between the lenses.
11. A system according to claim 1 , wherein the dispenser is configured to dispense a slurry having particles of lens material dispensed within a solvent.
12. A system according to claim 1 , wherein the first lens is a clear lens and the second lens is a polarizing lens.
13. A system according to claim 8 , wherein the lenses are polycarbonate lenses.
14. A system according to claim 1 , wherein the solvent comprises a ketone-based solvent.
15. A system according to claim 1 , wherein the deformable sheet is formed from cast silicone.
16. A system according to claim 1 , wherein the translation stage comprises a vacuum chuck to hold the first lens.
17. A system for bonding lenses, the system comprising:
a translation stage having a vacuum chuck configured to hold a first polycarbonate lens having a complex curvature, wherein the translation stage is configured to provide a force towards a base with a second polycarbonate lens having a complex curvature such that an apex of the first lens initially contacts a nadir of the second lens;
an alignment fixture mounted on the base and configured to conform to the curvature of the second lens to hold the second lens;
a dispenser for dispensing an adhesive solvent between the lenses;
a deformable sheet having a taut portion proximate to the alignment fixture and stretched across a jig mounted on the base, the deformable sheet configured to flex in response to the force so that either of the first or second lenses conforms to a curvature of the other, and so that the pressure of the first lens against the second lens presses the solvent radially outward from the nadir to the perimeter of the second lens, wherein the taut portion is substantially planar when the force is not being applied against the deformable sheet; and
wherein the translation stage is further configured to hold the first lens against the second lens with the pressure at the perimeters of the lenses such that the first lens bonds to the second lens using the solvent.