Patent ID: 7697205

Claim:
An anti-reflection structure, comprising: a plurality of convex parts arranged at pitches, each of which is shorter than a wave length of a visible light ray, each of the convex parts being formed into one of a substantially truncated cone and a substantially truncated pyramid, each including: a base face formed into one of a base circle and a base polygon inscribed in the base circle, the base circle and the base circle circumscribing about the base polygon each having a base diameter Db meeting the following expression: 100 nm<Db<380 nm, an upper face formed into one of an upper circle and an upper polygon inscribed in the upper circle, the upper circle and the upper circle circumscribing about the upper polygon each having an upper diameter Du meeting the following expression: 5 nm<Du<50 nm wherein each of the convex parts has a head end face which is so curved as to define a curvature radius R meeting the following expression: R ≧[{( Du 2 −Du·Db )/(4 ·H )} 2 +( Du/ 2) 2 ] 1/2 where H denotes a height of the each of the convex parts.