Patent ID: 7110643

Claim:
A micro lens array comprising: a plurality of micro lenses that are formed protrusively substantially in a shape of a hemisphere, and having one of a circular or a noncircular bottom face, said micro lenses being closely arranged in two dimensions, and a plurality of convex sub-lenses that are protrusively formed along the surface of said each micro lens so as to have one of a circular or a noncircular bottom face, said sub-lenses having a smaller curvature radius than that of said micro lenses, wherein said micro lens array is configured so that D sav /D is in a range from 0.1 to 0.3, where D is a micro lens bottom face width obtained by halving the summation of the maximum and the minimum width which are measured along a line passing through the center of the bottom face of said micro lens when the bottom face of said micro lens is not circular, or is a micro lens bottom face diameter when the bottom face of said micro lens is circular; D s is a sub-lens bottom face width obtained by halving the summation of the maximum and the minimum width which are measured along a line passing through the center of the bottom face of said sub-lens when the bottom face of said sub-lens is not circular, or is a sub-lens bottom face diameter when the bottom face of said sub-lens is circular; and D sav is an average sub-lens bottom face width obtained by averaging a plurality of said sub-lens bottom face widths D s , or is an average sub-lens bottom face diameter obtained by averaging a plurality of said sub-lens bottom face diameters Ds.