Luminaire with improved light utilization efficiency

Abstract

A lens array 22C has convex lenses 221 and 221C arranged in alternate and staggering manner to one another. In combination with a condenser lens 23, the convex lenses 221 form images of respective convex lenses 211 of a lens array 21 on a plane 24 to be illuminated in overlapping so that an illuminance distribution on the plane 24 is almost uniform, while the convex lenses 221C whose focal length is longer than that of the convex lenses 211 make on the plane 24 an illuminance distribution of a mountain-shape. Flat plate portions and concave lenses may be employed instead of the convex lenses 221C. A polarization conversion element comprises two elements and an element disposed therebetween with its longitudinal direction being perpendicular to the two element. The images of a light emitting part are included in band-shaped useful incident areas. A polarization conversion section comprises a middle part which is thin but has a larger divergent angle and side parts each has a smaller divergent angle and a simpler construction but is thicker with its size larger.

Dependencies are inferred from the claim text.