Abstract: A light converging sheet unit includes first and second light converging sheets stacked one on top of the other. The first light converging sheet has first light converging micro-prism structures with a first average peak-to-peak distance between adjacent ones of the first light converging micro-prism structures. The second light converging sheet has second light converging micro-prism structures with a second average peak-to-peak distance between adjacent ones of the second light converging micro-prism structures. At least one of the first and second average peak-to-peak distances is not larger than 35 ?m.

Abstract: A light converging sheet unit includes first and second light converging sheets stacked one on top of the other. The first light converging sheet has first light converging micro-prism structures with a first average peak-to-peak distance between adjacent ones of the first light converging micro-prism structures. The second light converging sheet has second light converging micro-prism structures with a second average peak-to-peak distance between adjacent ones of the second light converging micro-prism structures. At least one of the first and second average peak-to-peak distances is not larger than 35 ?m.

Abstract: An optical film includes a substrate unit and a light collecting layer. The substrate unit includes a substrate, and a light diffusing layer that is formed on the substrate, and that has a matrix body with a bottom surface contacting the substrate and a plurality of diffusing particles distributed in the matrix body. The percentage of an area of the diffusing particles projected onto a projection plane based on 100 percent of an area of the bottom surface of the matrix body projected onto the projection plane is greater than 25%. The light collecting layer is formed on the light diffusing layer.