Flexible film with surface relief and use thereof in electro-active optical systems
View Patent ↗The present invention relates generally to flexible thin films for use in electro-active optical systems. Embodiments of the invention include thin films having diffractive structures on at least one surface of the film, and methods of making such films. Embodiments of the invention also include lens blanks that comprise such thin films. Embodiments of the invention also include methods of making lens blanks that comprise such thin films.
1. A method of making a film having surface relief features, comprising:
providing a first substrate having a first surface, wherein the first substrate is composed of a water-soluble solid material;
providing a second substrate having a first surface, wherein the second substrate is composed of a solid material and the first surface of the second substrate comprises one or more relief structures;
providing a curable liquid material;
disposing the curable liquid material between the first surface of the first substrate and the first surface of the second substrate, wherein the first surface of the first substrate and the first surface of the second substrate are adjacent to each other;
curing the curable liquid material to form a polymeric film between the first surface of the first substrate and the first surface of the second substrate;
removing the first substrate from the polymeric film; and
incorporating the polymeric film into an electro-active system disposed on a lens or a lens blank, wherein:
the electro-active system has a curved substrate having a concave surface and a convex surface, wherein the concave surface is opposite the convex surface; and
the polymeric film is disposed on the concave surface of the curved substrate such that a naturally curved surface of the polymeric film faces the concave surface of the curved substrate.
2. The method of claim 1 , wherein the water-soluble solid material comprises a water-soluble polymer.
3. The method of claim 2 , wherein the water-soluble polymer comprises polyvinyl alcohol, a polyacrylamide, a polyacrylic acid, a polyisocyanate, a starch, or a cellulose.
4. The method of claim 3 , wherein the water-soluble polymer comprises polyvinyl alcohol.
5. The method of claim 1 , wherein the first surface of the first substrate is a curved surface.
6. The method of claim 5 , wherein the first surface of the second substrate is a curved surface.
7. The method of claim 6 , wherein the radius of curvature of the first surface of the first substrate is within 15% of the radius of curvature of the first surface of the second substrate.
8. The method of claim 7 , wherein one of the first surfaces is a convex surface and the other is a concave surface.
9. The method of claim 1 , wherein the curable liquid material is a liquid monomer, a liquid oligomer, or a mixture thereof.
10. The method of claim 9 , wherein the curable liquid material is a photo-curable material.
11. The method of claim 9 , wherein the curable liquid material is a thermally curable material.
12. The method of claim 1 , wherein the one or more relief structures are inverted diffractive structures.
13. The method of claim 12 , wherein the one or more relief structures have a height that ranges from 1 nm to 500 μm.
14. The method of claim 1 , wherein the first surface of the second substrate comprises a plurality of relief structures, and wherein one or more adjacent pairs of relief structures are separated by a distance ranging from 1 nm to 500 μm.
15. The method of claim 1 , wherein the disposing the curable liquid material between the first surface of the first substrate and the first surface of the second substrate comprises separating the first surface of the first substrate from the first surface of the second substrate by a distance of 1 μm to 1 mm.
16. The method of claim 1 , wherein the curing comprises heating the liquid curable material.
17. The method of claim 1 , wherein the curing comprises exposing the liquid curable material to ultraviolet light.
18. The method of claim 1 , wherein the polymer film is transparent.
19. The method of claim 1 , wherein the removing the first substrate from the polymeric film comprises exposing the first substrate to an aqueous medium.
20. The method of claim 1 , further comprising:
removing the polymeric film from the second substrate.
21. The method of claim 1 , wherein the polymeric film comprises:
a naturally curved first surface; and
a naturally curved second surface disposed opposite the naturally curved second surface, wherein the naturally curved second surface comprises one or more relief structures;
wherein the naturally curved first surface is concave, and the naturally curved second surface is convex, and wherein the radius of curvature of the naturally curved first surface is within 15% of the radius of curvature of the naturally curved second surface.
22. The method of claim 1 , further comprising:
providing a curved substrate of an electro-active system, the curved substrate having a concave surface and a convex surface, wherein the concave surface is opposite the convex surface;
securing polymeric film to the curved substrate such that the naturally curved second surface of the thin film faces the concave surface of the curved substrate and forms a sealed cavity between the thin film and the curved substrate;
injecting an electro-active material into the sealed cavity via an injection site in the thin film.
23. The method of claim 1 , wherein the first substrate and the second substrate are disposed adjacent to each other and the curable liquid material is disposed between the first substrate and the second substrate to fill a space between the first substrate and the second substrate.