LIGHTING DEVICE

PROBLEM TO BE SOLVED: To provide a lighting device which can easily be made compact and is capable of irradiation with distortion-free illumination light with uniform illuminance. SOLUTION: Respective lens portions 23b constituting a fly-eye lens 23 are formed in a plane circular shape. Consequently, incoming and outgoing surfaces of each lens portion 23b can be set to have small curvature and a focal length of each lens portion 23b can be set short. The fly-eye lens can, therefore, be made thin and the lighting device can easily be made compact. Further, the respective lens portions 23b are formed in the plane circular shape and then local distortion of luminous flux (l) projected from each lens portion 23b can accurately be suppressed. An area on the fly-eye lens 23 other than the lens portions 23b is shielded from light by a light shield mask 24 and then unnecessary light 41 transmitted through a lens substrate 23a as it is is prevented from being incident on an irradiated area Al. COPYRIGHT: (C)2007,JPO&INPIT