LIGHTING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a lighting device configured to effectively obscure speckle, while using light from a light source with a high utilization rate.SOLUTION: A lighting device 40 includes: an irradiation device 70; a diffusion element 50; a first lens array 55; a second lens array 60; and a deflection element 65 along an optical path in this order. Diffusion light that is incident and diffused on a certain region on the diffusion element and the diffusion light that is incident and diffused on another region different from the certain region on the diffusion element advance into a region at least partially overlapped with each other. A diffusion angle &thetas;of the diffusion light emitted from the diffusion element is equal to or less than a prospective angle &thetas;formed between two line segments LS which extend to both ends of a first unit lens of a first lens array 55 from a main point 61a of a second unit lens of a second lens array 60.