Patent ID: 8013950

Claim:
An optical sheet combination structure disposed between a polarizer and a surface emitting unit, comprising: a first optical sheet including a transparent base layer and an array of columnar cubic structures of curing resin integrally laminated on the transparent base layer, a valley portion between adjacent cubic structures contacting a surface of the transparent base; and a second optical sheet disposed nearer to the side of the polarizer than the first optical sheet, having a number of columnar cubic structures arrayed on a surface, and a refractive index of the cubic structures along an extension direction thereof being different from a refractive index of the cubic structures along an array direction thereof, wherein the first and second optical sheets are disposed with prism formed planes faced to a side of the polarizer, and wherein the first and second optical sheets are combined by making the extension directions of the cubic structures of the first and second optical sheets cross at right angles, wherein the transparent base layer has dents corresponding to valley portions between the cubic structures that extend along an extension direction of the cubic structures.