A single packet reflective polarizer having an adjusted thickness profile for low color at an oblique angle

摘要

Multilayer optical film reflective polarizers previously considered to have excessive off-axis color can be used in an " on-glass " configuration in which they are laminated to a back-absorption polarizer of a display, without any light- LC display can provide adequate performance. The reflective polarizer is a TOP (tentered-one-packet) multilayer film that has only one packet of microlayers and is oriented using a standard tenter so that the birefringent microlayers of the film are birefringent birefringent. The thickness profile of optical repeat units (ORUs) in the microlayer packet is adjusted to avoid excessive background color at the vertical and tilt angles. The color at high oblique angles in the white state of the display is determined by locating the thicker ORUs closer to the absorbance polariser and by the average slope from ORU 600 to ORU 645 Is less than 1.8 times the average slope from the ORU 450 to the ORU 600.