Patent ID: 7614776
Filing Date: 2009-11-10
Classification: G02B

Abstract:
1. A diffusing board in which a synthesized pattern obtained by overlapping a first uneven shape including a plurality of concavities or convexities for diffusing incident light in one plane including the optical axis of said incident light and a second uneven shape including a plurality of concavities or convexities for diffusing the incident light about the optical axis of said incident light is formed on either side of a substrate, light entering the substrate from one side thereof and exiting the same from the other side thereof, wherein the shape of a surface of the synthesized pattern is expressed by: wherein the first uneven shape is formed by periodically arranging linear concavities or convexities which are long in one direction; and the second uneven shape is formed by arranging spherical or conical concavities or convexities in a non-periodic manner such that there are no gaps between the spherical concavities or convexities, and wherein the maximum size of the concavities or convexities forming the second uneven shape is in the range between one-thirds and three times, inclusive, of the period of arrangement of the concavities or convexities forming the first uneven shape when viewed in a direction perpendicular to the substrate.