LOW LAYER COUNT REFLECTIVE POLARIZER WITH OPTIMIZED GAIN

摘要

Multilayer reflecting polarizing films are disclosed having increased in-plane refractive index differences between adjacent microlayers along both the pass and block axis, and having negative refractive index differences between adjacent microlayers along the thickness or z-axis. Major front and back surfaces of the film exposed to air provide a Fresnel reflectivity component to the pass axis reflectivity, and the microlayers provide a microlayer component to the pass axis reflectivity, such microlayer component preferably having a reflectivity of p-polarized light that increases with incidence angle faster than the Fresnel reflectivity component decreases so as to substantially avoid off-axis gain peaks for p-polarized light. The films preferably utilize a relatively small total number of microlayers, arranged in a single coherent stack with monotonic optical repeat unit thickness profile, and at least some microlayers preferably include polyethylene naphthalate or a copolymer thereof.