White-Internal-Cavity Spherical Luminaire for Theatrical Lighting

Abstract

Since the adoption of LEDs in theatrical lighting, color mixing has become a widely pursued interest. While many methods used today can output beams with color uniformity of around 3x to 5x MacAdam ellipse distributions, a white internal cavity of a sphere can reduce the color uniformity distribution down to a 1x MacAdam ellipse mix. This white-internal-cavity sphere can serve as a theatrical spherical luminaire that will mix and project different colored sources into a single homogenized beam to serve as a light engine for theatrical fixtures. The idea is derived from the concept of an integrating sphere used for measuring illumination sources. In an integrating sphere, an external source is shone into the sphere which has a hollowed-out cavity painted with a special white paint. The light is then mixed within the sphere by being scattered by the paint. A detector sitting at a different port then measures the light coming out of the sphere.The idea here is that we can take multiple color LED sources and mix them within a sphere that can then project them out to be used in a theatrical lighting system.