Patent ID: 9614136
Date: 2017-04-04
CPC Classifications: H01L

Claim:
1. An optical substrate that includes a substrate and a concave-convex structure which is formed in a part or a whole of a surface of the substrate, wherein at least one region of the concave-convex structure includes a plurality of convex portions arranged apart from each other, wherein the plurality convex portions are arranged in the form of a triangular lattice, a square lattice or a hexagonal lattice or an arrangement where their lattice number is regularly varied, wherein the plurality of convex portions include a plurality of first convex portions, each having a first height, and a plurality of second convex portions, each having a second height lower than the first height, wherein each of the first convex portions is adjacent to at least one other of the first convex portions without any of the second convex portions provided therebetween, wherein the following formulas (1), (2) and (3) are satisfied: P H hn designates the second height of each of the second convex portions, N N