BRIGHTNESS ENHANCING FILM WITH EMBEDDED DIFFUSER

摘要

Brightness enhancing films with embedded diffusers are described. More specifically, films including a birefringent substrate, a prismatic layer carried by the substrate having linear prisms, and an embedded structured surface disposed between the substrate and the prismatic layer are disclosed. The embedded structured surface may include closely-packed structures. Processes for producing embedded structured surfaces having particular topographies are also disclosed.

主权项

1. An optical film, comprising:
a birefringent substrate; a prismatic layer carried by the substrate, the prismatic layer having a major surface comprising a plurality of side by side linear prisms extending along a same prism direction; and an embedded structured surface disposed between the substrate and the prismatic layer comprising closely-packed structures arranged such that ridges are formed between adjacent structures, the structures being limited in size along two orthogonal in-plane directions; wherein the embedded structured surface has a topography characterizable by a first and second Fourier power spectrum associated with respective first and second orthogonal in-plane directions, and wherein
to the extent the first Fourier power spectrum includes one or more first frequency peak not corresponding to zero frequency and being bounded by two adjacent valleys that define a first baseline, any such first frequency peak has a first peak ratio of less than 0.8, the first peak ratio being equal to an area between the first frequency peak and the first baseline divided by an area beneath the first frequency peak, andto the extent the second Fourier power spectrum includes one or more second frequency peak not corresponding to zero frequency and being bounded by two adjacent valleys that define a second baseline, any such second frequency peak has a second peak ratio of less than 0.8, the second peak ratio being equal to an area between the second frequency peak and the second baseline divided by an area beneath the second frequency peak; and wherein the embedded structured surface is characterized by a total ridge length per unit area in plan view of less than 200 mm/mm2