IMPROVED ILLUMINATION SYSTEM FOR SURGERY OPERATION LECTURE HALL, ETC.

摘要

PURPOSE: To provide a very great depth of field so as to perform uniform illumination over a very wide distance range by using a toroidal lens system using a plastic conical Fresnel lens. CONSTITUTION: A lens part of a toroidal lens system is a plastic molding conical Fresnel lens. That is, a luminaire is constructed of a light source 80, a planar field 10 consisting of a plurality of outward curved prisms and serving a radial sector, and the toroidal lens system using a plastic conical Fresnel lens 70, which regulates divergence of light emitted from the light source 80 and transforms it into substantially columnar light so as to radiate it toward the planar field 10. Curvatures of the lateral/outward curved prisms are varied, and a curvature of a prison on the central side of the planar circular prism field 10 is larger than that on the outer circumference side. In this case, divergence of light emitted from a prism in a predetermined radial sector is regulated in the angular direction. In this way, a depth of field can be improved.