PARALLEL BEAM RADIATION DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a parallel beams radiation device for emitting highly accurate parallel beams. SOLUTION: A Fresnel zone plate 2 is disposed as a condensing part at a position separated a sufficient distance L from a light-emitting part 3b of an LED 3 to the diameter of light-emitting, and a light shielding part 1b composing a total reflection surface around the Fresnel zone plate 2 is provided. A Collimator part 1a which turns a secondary light source to the focus is provided against the secondary light source of the minimum spot formed at the focus of the Fresnel zone plate 2.