Process for forming reflective polarizer
Assignee3M Innovative Properties Company
InventorsJames M. Jonza, Michael F. Weber, Andrew J. Ouderkirk, Carl A. Stover
Life of this patent
Estimating the term…
Abstract
A method of forming a reflective polarizer comprising orienting a multilayer film formed from alternating layers of a first polymeric material and a second polymeric material in a first in-plane axis direction while allowing dimensional relaxation in an orthogonal second in-plane axis direction to produce specified differences in the refractive indices of the first and second polymeric materials in the first and second in-plane directions and in the thickness direction.
Claims29
A process for forming a reflective polarizer, the process comprising the steps of:
- forming a multilayer film comprising alternating layers of a first stress-induced birefringent polymeric material and second polymeric material, the film being defined in reference to a coordinate system of first and second orthogonal in-plane axes and a third mutually orthogonal axis in a thickness direction of the film;
- and
- stretching the film along the first in-plane axis of the film while allowing dimensional relaxation of the film along the second in-plane axis of the film to achieve a desired relationship among refractive indices of the first and second polymeric material along the first, second and third axes.
A process for forming a reflective polarizer, the process comprising the steps of:
- forming a multilayer film comprising alternating layers of a first stress-induced birefringent polymeric material and second polymeric material, the film being defined in relationship to a coordinate system of first and second orthogonal in-plane axes and a third mutually orthogonal axis in a thickness direction of the film, each material having respective refractive indices along the first, second and third axes;
- and
- stretching the film along the first in-plane axis of the film while allowing dimensional relaxation of the film along the second in-plane axis of the film to produce a difference in the refractive indices of the first and second polymeric materials along the first in-plane axis, the second material being selected such that, after stretching, any difference between the refractive index of the first material along the second in-plane axis of the film and the refractive index of the second material along the second in-plane axis of the film, and any difference in the refractive index of the first material along the third axis of the film and the refractive index of the second material along the third axis of the film are less than 50% of the difference in the refractive indices of the first and second polymeric materials along the first in-plane axis of the film.
Dependencies are inferred from the claim text.