Patent ID: 9075177
Filing Date: 2015-07-07
Classification: G02B

Abstract:
1. An optical member comprising an array of total internal reflection structures, the optical member comprising: an optically transmissive film having a surface; a first plurality of non-intersecting elongate features formed in the surface; and a second plurality of non-intersecting elongate features formed in the surface, the first plurality of non-intersecting elongate features being oriented at an angle with respect to the second plurality of non-intersecting elongate features that is less than 30°, wherein each of the non-intersecting elongate features in the first plurality extends across the multiple non-intersecting elongate features in the second plurality thereby defining the total internal reflection structures, and at least one of the total internal reflection structures comprises a prism having facets having rounded edges, wherein at least a portion of the second plurality of nonintersecting elongate features has a height or depth that is smaller than a height or depth of at least a portion of the first plurality of non-intersecting elongate features but that is greater than 50% of the height or depth of the portion of the first plurality of non-intersecting elongate features, wherein a thickness of the optically transmissive film is selected based at least partly on a pitch of at least some non-intersecting elongate features of the first plurality or the second plurality so as to provide a desired on-axis luminance enhancement of light passing through the film.