Diffusely reflecting multilayer polarizers and mirrors
AssigneeMinnesota Mining and Manufacturing Company
InventorsSanford Cobb, Jr., Brian D. Cull, Andrew J. Ouderkirk, Michael F. Weber, David L. Wortman
Life of this patent
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Abstract
Highly efficient diffusely reflecting multilayer mirrors diffusely reflect light incident upon them. Highly efficient diffusely reflecting multilayer polarizers diffusely reflect light of one polarization while diffusely transmitting the other polarization. The diffusely reflecting mirror includes a light diffusing element and a multilayer mirror element. The diffusely reflecting polarizer includes a light diffusing element and a multilayer reflective polarizing element.
Claims31
A diffusely reflecting polarizer, comprising:
- a diffusing element adapted to alter direction of and to substantially maintain polarization of light incident upon it;
- and
- a reflective polarizing element, wherein the reflective polarizing element reflects light of a first polarization and transmits light of a second polarization;
- such that the light of the second polarization is diffusely transmitted by the diffusely reflecting polarizer.
A diffusely reflecting mirror, comprising:
- a diffusing element adapted to alter the direction of and to substantially maintain the polarization of light incident upon it;
- and
- a reflective mirror element which reflects light of a first and second polarization;
- wherein said diffusing element is an adhesive.
A diffusely reflecting mirror, comprising:
- a diffusing element adapted to alter the direction of and to substantially maintain the polarization of light incident upon it;
- and
- a reflective mirror element which reflects light of a first and second polarization;
- wherein the reflective mirror element comprises a plurality of layers, and further wherein a refractive index difference between at least two adjacent layers in a first in-plane direction and a refractive index difference between the at least two adjacent layers in a second in-plane direction are greater than a refractive index difference between the at least two adjacent layers in a third out-of-plane direction.
A diffusely reflecting polarizer, comprising:
- a diffusing element having a reflectivity of less than 20%, said diffusing element adapted to alter the direction of light incident upon it;
- and
- a reflective polarizing element which reflects light of a first polarization and transmits light of a second polarization;
- wherein the reflective polarizing element comprises a plurality of layers, wherein a refractive index difference between at least two adjacent layers in a first in-plane direction and a refractive index difference between the at least two adjacent layers in a second in-plane direction are greater than a refractive index difference between the at least two adjacent layers in a third out-of-plane direction, and wherein at least 70% of the light transmitted by the diffusing element is in its initial state of polarization.
Dependencies are inferred from the claim text.