CURVED LENSES AND RELATED METHODS

• US 20120262669A1
• Filed: 04/16/2012
• Published: 10/18/2012
• Est. Priority Date: 04/15/2011
• Status: Active Grant

• Current Assignee: Safilo SpA (Safilo Group SPA)
• Original Assignee: Polaroid Eyewear US LLC (PLR IP Holdings LLC)
• Inventors: BOINARD, ERIC, BOINARD, PASCAL
• Granted Patent: US 8,556,418 B2
• Time in Patent Office: Days
• US Class Current: 351/159.56
• CPC Class Codes: B29C 43/021 characterised by the shape of the surface
• CPC Class Codes: B29C 43/3697 comprising rollers or belts cooperating with non-rotating mould parts
• CPC Class Codes: B29C 51/14 using multilayered preforms or sheets
• CPC Class Codes: B29C 51/22 rotatable about an axis
• CPC Class Codes: B29D 11/00644 polarizing
• CPC Class Codes: B29D 11/0073 Optical laminates
• CPC Class Codes: B29L 2011/0016 Lenses
• CPC Class Codes: G02B 5/30 Polarising elements light-modulating devices with active elements G02F1/00
• CPC Class Codes: G02B 5/3025 Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state G02B5/3008, G02B5/3016 take precedence
• CPC Class Codes: G02B 5/305 including organic materials, e.g. polymeric layers
• CPC Class Codes: G02C 7/12 Polarisers
• CPC Class Codes: G03F 7/0002 Lithographic processes using patterning methods other than those involving the exposure to radiation, e.g. by stamping

Abstract

Curved lenses and methods for making curved lenses are described. One embodiment of a method of making a curved lens includes curving a lens blank made of a linear polarizer layer laminated together with a plurality of polymeric layers. The lens blank is curved by engendering rotational motion about a rotational axis of a roller having a forming surface thereon and lateral motion of a belt in contact with the forming surface. The lens blank is heated and pressed between the belt and the forming surface at a pressure, the pressure being supplied by tension on the belt. The pressure is maintained for a time sufficient to allow the lens blank to conform to the shape of the forming surface. Methods of the invention may be used to make curved lenses with different polarization properties and curvatures.

Claims

1. A method of making a formed lens, the method comprising:

obtaining a lens blank comprising, in superposed relation, a linear polarizer layer laminated together with a plurality of polymeric layers, the linear polarizer layer having a polarization axis;

engendering rotational motion about a rotational axis of a roller having a forming surface thereon and lateral motion of a belt in contact with the forming surface, wherein the lateral motion is non-parallel to the rotational axis;

heating and pressing the lens blank between the belt and the forming surface at a pressure, the pressure being supplied by tension on the belt;

maintaining the pressure for a time sufficient to allow the lens blank to conform to the shape of the forming surface.

2. The method of claim 1, wherein heating is conducted at about 70°

C. to about 200°

C.

3. The method of claim 1, further comprising cooling the lens blank while maintaining the pressure.

4. The method of claim 3, wherein cooling is conducted at about 20°

C. to about 90°

C.

5. The method of claim 1, further comprising, preheating the lens blank to a temperature of about 20°

C. to about 150°

C. prior to pressing.

6. The method of claim 1, wherein the lateral motion is at a speed of about 0.1 meters/minute to about 10 meters/minute and pressing is achieved during lateral motion.

7. The method of claim 1, wherein at least one of the polymeric layers is an optical wave retarder having a fast axis and the fast axis is aligned at an angle relative to the polarizer axis.

8. The method of claim 7, wherein the angle renders the lens a linear polarizer.

9. The method of claim 7, wherein the angle renders the lens an elliptical polarizer.

10. The method of claim 7, wherein the angle renders the lens a circular polarizer.

11. The method of claim 10, further comprising coating a concave surface and a convex surface of the formed lens with an anti-reflective coating.

12. The method of claim 11, wherein the formed lens has a parallel polarizer transmittance equal to or greater than 90% and a cross polarizer transmittance equal to or less than 0.5%.

13. The method of claim 1, wherein the shape of the roller produces a cylindrically shaped lens having a first radius of curvature and a second radius of curvature perpendicular to the first radius of curvature, wherein the first radius of curvature is non-zero and the second radius of curvature is zero.

14. An eyeglass lens made according to the method of claim 1.

15. A method of making a formed lens, the method comprising:

obtaining a lens blank comprising, in superposed relation, a linear polarizer layer laminated together with a plurality of polymeric layers, the linear polarizer layer having a polarization axis;

placing the lens blank between a continuously rotating cylindrical roller and a belt;

heating the lens blank to a forming temperature by pressing the lens blank at a pressure between the cylindrical roller and belt, the cylindrical roller being at the forming temperature;

maintaining the pressure while heating at the forming temperature for allowing the lens blank to conform to the shape of the cylindrical roller;

reducing the temperature to a reduced temperature while maintaining the pressure for allowing the lens blank to become a rigid lens having a convex side and a concave side; and

removing the rigid lens from between the cylindrical roller and belt.

16. The method of claim 15, wherein the roller and belt are in continuous rotation at a speed of about 0.1 meters/minute and about 10 meters/minute.

17. The method of claim 15, wherein the forming temperature is about 70°

C. to about 200°

C.

18. The method of claim 15, wherein the reduced temperature is about 20°

C. to about 90°

C.

19. The method of claim 15, further comprising, preheating the lens blank to a temperature of about 20°

C. to about 150°

C. prior to applying the pressure.

20. The method of claim 15, wherein at least one of the polymeric layers is an optical wave retarder having a fast axis and the fast axis is aligned at an angle relative to the polarizer axis.

21. The method of claim 20, wherein the angle renders the lens a linear polarizer.

22. The method of claim 20, wherein the angle renders the lens an elliptical polarizer.

23. The method of claim 20, wherein the angle renders the lens a circular polarizer.

24. The method of claim 23, further comprising coating a concave surface and a convex surface of the formed lens with an anti-reflective coating.

25. The method of claim 24, wherein the formed lens has a parallel polarizer transmittance equal to or greater than 90% and a cross polarizer transmittance equal to or less than 0.5%.

26. The method of claim 15, wherein the shape of the roller produces a cylindrically shaped lens having a first radius of curvature and a second radius of curvature perpendicular to the first radius of curvature, wherein the first radius of curvature is non-zero and the second radius of curvature is zero.

27. An eyeglass lens made according to the method of claim 15.

28. A method of making eyewear, the method comprising:

(a) obtaining a first lens and a second lens, the first lens and second lens comprising, in superposed relation, a linear polarizer layer laminated together with a plurality of polymeric layers, the linear polarizer layer having a polarization axis, the first lens and second lens being formed from lens blanks into a desired shape according to the following steps;

(i) engendering rotational motion about a rotational axis of a roller having a forming surface thereon and lateral motion of a belt in contact with the forming surface, wherein the lateral motion is non-parallel to the rotational axis;

(ii) heating and pressing the lens blanks separately between the belt and the forming surface at a pressure, the pressure being supplied by tension on the belt member;

(iii) maintaining the pressure for a time sufficient to allow the lens blank to conform to the shape of the roller; and

(b) placing the first lens and second lens into an eyeglass frame.