DOUBLE-SIDED OPTICAL FILM WITH LENSLETS AND CLUSTERS OF PRISMS

摘要

An optical film has a structured surface with elongated lenslets formed therein and an opposed structured surface with elongated prisms formed therein. The lenslets extend parallel to each other and to an elongation axis which is generally parallel to the film plane, and the prisms also extend parallel to each other and to the elongation axis. The prisms are grouped into separated clusters of adjacent prisms. Each prism cluster is associated with a corresponding one of the lenslets, and has at least 3 prisms. Each lenslet defines a focal point and a focal surface. Vertices of the prisms in a prism cluster are disposed at or near the focal surface of the associated lenslet. When illuminated with oblique light, each lenslet/prism cluster pair, and optionally the optical film as a whole, may produce N angularly separated light beams, N being the number of prisms in each prism cluster.

主权项

1. An optical film having opposed first and second structured surfaces, the optical film comprising:
a plurality of elongated lenslets formed on the first structured surface, the lenslets being elongated along respective lenslet axes which are parallel to an elongation axis; and a plurality of elongated prisms formed on the second structured surface, the prisms having respective elongated prism vertices which are also parallel to the elongation axis; wherein the prisms are grouped into prism clusters that are separated from each other, each prism cluster having at least three of the prisms, and each prism cluster being associated with a corresponding one of the lenslets; wherein each lenslet defines a focal surface, and wherein for each lenslet, the prism vertices of the prisms in the prism cluster associated with the lenslet are disposed at or near the focal surface.