Patent ID: 7944614

Claim:
A light converging sheet unit comprising: a first light converging sheet having a base layer, and a plurality of first light converging micro-prism structures that protrude from a top surface of said base layer and that extend in a first direction; and a second light converging sheet having a base layer, and a plurality of second light converging micro-prism structures that protrude from a top surface of said base layer of said second light converging sheet and that extend in a second direction different from the first direction, said first and second light converging sheets being stacked one on top of the other; wherein said first light converging micro-prism structures have a first average peak-to-peak distance between adjacent ones of said first light converging micro-prism structures, and said second light converging micro-prism structures have a second average peak-to-peak distance between adjacent ones of said second light converging micro-prism structures, at least one of the first and second average peak-to-peak distances being not larger than 35 μm.