Partially reflecting multilayer optical films with reduced color

摘要

A multilayer optical film body includes a first and second packet of microlayers. Each packet partially transmits and partially reflects light over an extended wavelength range, such as the visible region, for normally incident light polarized along a first principal axis of the film body. In combination, the first and second packets have an intermediate reflection and transmission (e.g. 5-95% internal transmission, on average) for the normally incident light, and similar intermediate reflection/transmission (e.g. 10-90% internal transmission, on average) for oblique light. The packets are laminated or otherwise connected so that light can pass through the packets sequentially. In at least a first test area of the film body, a high frequency spectral variability of the combination of packets is less than a high frequency spectral variability of the first packet by itself, and may also be less than a high frequency spectral variability of the second packet by itself.

主权项

1. A partially reflective multilayer optical film body having a first principal in-plane axis, comprising:
a first packet of microlayers; and a second packet of microlayers connected to the first packet such that at least some light can pass through the first and second packets of microlayers sequentially; wherein the first and second packets are each configured to partially transmit and partially reflect, over an extended wavelength range, normally incident light linearly polarized along the first principal in-plane axis; wherein the first and second packets, in combination, have a first combined internal transmission in a range from 0.05 (5%) to 0.95 (95%) for the normally incident light when averaged over the extended wavelength range; wherein the first and second packets, in combination, have a second combined internal transmission for oblique light that is (a) incident at 60 degrees in a first principal plane containing the first principal in-plane axis, and (b) linearly polarized in the first principal plane, the second combined internal transmission being in a range from 0.1 (10%) to 0.9 (90%) when averaged over the extended wavelength range; wherein, at least in a first test area of the multilayer optical film body, a combined high frequency spectral variability (Δcomb) of the first and second packets in combination is less than a first high frequency spectral variability (Δ1) of the first packet by itself