Optical Film Stack for Light Duct

Abstract

A film stack reflects incident light in some areas and transmits incident light in other areas, and it redirects incident light with one or more structured surfaces. The spatially variable reflection and transmission is achieved at least in part with reflective strips, and the reflective strips are attached to a first major surface of a structured optical film in the film stack. A second major surface of the structured optical film, opposite the first major surface, attaches to a substrate. The reflective strips attach to the structured optical film by a first discontinuous adhesive layer, having first adhesive areas. The structured optical film attaches to the substrate by a second discontinuous adhesive layer, having second adhesive areas. A major portion of the first adhesive areas, and a major portion of the second adhesive areas, is circumscribed by the reflective strips. The film stack may be part of a light duct.

Dependencies are inferred from the claim text.