Interior illumination apparatus using sunlight

Abstract

An apparatus for collecting sunlight and directing the collected sunlight into the interior of the building to provide illumination, so that the energy used for artificial illumination can be conserved, includes a collector, a light pipe, and a diffuser. The collector includes an immovable flared trumpet-like hollow tube having a highly reflective interior surface and having its larger aperture oriented to maximize the sunlight received at a particular time of day. The larger aperture is closed by a transparent cap which supports a secondary reflector that extends forward of the larger aperture. The secondary reflector serves to reflect into the hollow tube light travelling at a low angle of incidence with respect to the larger aperture to compensate for the reduced efficiency of the larger aperture to low-angle light. The apparatus also includes a sprinkler for washing dust and other deposits from the transparent cap, and further includes a servo-controlled light valve for maintaining, to the extent possible, a constant level of illumination at a work station within the building.

Dependencies are inferred from the claim text.