To miniaturize a lens array equipped with a polarized light conversion device.

This device is provided with the polarized light conversion device constituted of polarizing beam splitters 4... on which respective beams from small lens trains (2 (1, 1) to 2 (4, 1)) arranged on the plane 2 of a 1st lens array are made incident, mirrors 5... reflecting reflected light and 1/2 λplates 6... so as to irradiate small lenses 3 (1, 1) to 3 (8, 1) formed on the plane 3 of a 2nd lens array with either polarized wave (s-wave). Since the curved surface of the small lens of the 1st lens array is deformed so that the beams 8 and 8 in an up-and-down direction may be somewhat refracted in an optical axis P direction, the 2nd lens array are arranged so that a gap between the small lens groups of the 2nd lens array may be eliminated. As a result, the polarized light conversion device and the 2nd lens array 3 are made small in size.