Patent ID: 6857762

Claim:
A ring illuminator, comprising: a light source that includes a plurality of light emitting elements that are arranged around an optical axis of an optical system, the light emitting elements including at least two groups of light emitting elements having light emitting colors different from each other, each group of light emitting elements that emit the same color light being arranged in a substantially ring shaped configuration around the optical axis on a ring plane oriented substantially orthogonally to the optical axis; a combining unit that combines light beams radiating from the light emitting elements and having light emitting colors different from each other to generate illumination light having a given hue, the combining unit located downstream from the light emitting elements along light emitting directions of the light emitting elements; and a focusing unit that focuses the illumination light at a given position along the optical axis, the focusing unit located downstream from the combining unit along an advancing direction of the generated illumination light from the combining unit, the advancing direction extending substantially parallel to the ring plane, the focusing unit including a reflection mirror that reflects and focuses the illumination light from the combining unit to the given position.