Convex multilayer reflective polarizer
A multilayer reflective polarizer convex along orthogonal first and second axes orthogonal to an optical axis passing thorough an apex of the multilayer reflective polarizer is described. The multilayer reflective polarizer has at least one first location having a radial distance r 1 from the optical axis and a displacement s 1 from a plane perpendicular to the optical axis at the apex, where s 1 /r 1 is in a range of about 0.2 to about 0.8. The multilayer reflective polarizer may have at least one inner layer substantially optically uniaxial at at least one first location away from the apex. For an area of the reflective polarizer defined by s 1 and r 1 , a maximum variation of a transmission axis of the reflective polarizer may be less than about 2 degrees.
1. A multilayer reflective polarizer convex along orthogonal first and second axes orthogonal to an optical axis passing thorough an apex of the multilayer reflective polarizer, the multilayer reflective polarizer having:
at least one inner layer substantially optically uniaxial at at least one first location on the at least one inner layer away from the apex; and
at least one first location on the reflective polarizer having a radial distance, r 1 , from the optical axis and a displacement, s 1 , from a plane perpendicular to the optical axis at the apex, s 1 /r 1 being in a range of about 0.2 to about 0.8.
2. The multilayer reflective polarizer of claim 1 , wherein for an area of the reflective polarizer defined by s 1 and r 1 , a maximum variation of a transmission axis of the reflective polarizer is less than about 2 degrees.
3. The multilayer reflective polarizer of claim 2 , wherein the maximum variation of the transmission axis of the reflective polarizer is less than about 1.5 degrees.
4. The multilayer reflective polarizer of claim 1 , wherein the at least one inner layer is substantially optically biaxial at at least one second location on the at least one inner layer away from the apex.
5. The multilayer reflective polarizer of claim 1 , wherein s 1 /r 1 is in a range of about 0.3 to about 0.6.
6. The multilayer reflective polarizer of claim 1 , wherein the reflective polarizer has a second location having a radial distance, r 2 , from the optical axis and a displacement, s 2 , from the plane, s 2 /r 2 being at least 0.3.
7. The multilayer reflective polarizer of claim 1 , wherein an azimuthal variation in s 1 /r 1 is less than 2 percent.
8. The multilayer reflective polarizer of claim 1 , wherein an azimuthal variation in s 1 /r 1 is less than 1 percent.
9. The multilayer reflective polarizer of claim 1 comprising alternating polymeric layers.
10. A lens having a surface curved about two orthogonal directions and comprising the multilayer reflective polarizer of claim 1 disposed on and substantially conforming to the surface.
11. A multilayer reflective polarizer convex along orthogonal first and second axes orthogonal to an optical axis passing thorough an apex of the multilayer reflective polarizer, the multilayer reflective polarizer having:
at least one first location on the reflective polarizer having a radial distance, r 1 , from the optical axis and a displacement, s 1 , from a plane perpendicular to the optical axis at the apex, s 1 /r 1 being in a range of about 0.2 to about 0.8,
wherein for an area of the reflective polarizer defined by s 1 and r 1 , a maximum variation of a transmission axis of the reflective polarizer is less than about 2 degrees.
12. The multilayer reflective polarizer of claim 11 , wherein the maximum variation of the transmission axis of the reflective polarizer is less than about 1.5 degrees.
13. The multilayer reflective polarizer of claim 11 comprising at least one layer that is substantially optically biaxial at at least one first location on the at least one layer away from the optical axis and substantially optically uniaxial at at least one second location away from the optical axis.
14. The multilayer reflective polarizer of claim 13 , wherein s 1 /r 1 is in a range of about 0.3 to about 0.6.
15. The multilayer reflective polarizer of claim 11 , wherein the reflective polarizer has a second location having a radial distance, r 2 , from the optical axis and a displacement, s 2 , from the plane, s 2 /r 2 being at least 0.3.
16. The multilayer reflective polarizer of claim 11 , wherein an azimuthal variation in s 1 /r 1 is less than 2 percent.
17. The multilayer reflective polarizer of claim 11 , wherein an azimuthal variation in s 1 /r 1 is less than 1 percent.
18. The multilayer reflective polarizer of claim 11 comprising alternating polymeric layers.
19. A lens having a surface curved about two orthogonal directions and comprising the multilayer reflective polarizer of claim 11 disposed on the surface.
20. A multilayer reflective polarizer convex along orthogonal first and second axes orthogonal to an optical axis passing thorough an apex of the multilayer reflective polarizer, the multilayer reflective polarizer comprising alternating polymeric layers and having:
at least one inner layer substantially optically uniaxial at at least one first location on the at least one inner layer away from the apex; and
at least one first location on the reflective polarizer having a radial distance, r 1 , from the optical axis and a displacement, s 1 , from a plane perpendicular to the optical axis at the apex, s 1 /r 1 being at least 0.3,
wherein for an area of the reflective polarizer defined by s 1 and r 1 , a maximum variation of a transmission axis of the reflective polarizer is less than about 2 degrees.