Patent attributes
A high-efficiency lamp, emitting light from a front surface, and having a high-efficiency light source, producing a first light beam. An iris assembly has an annular body that defines a first annulus and has iris blades which can be extended into the annulus to form a second, smaller, annulus. This iris assembly is positioned relative to the light source so that the iris blades are in front of the high-efficiency light source. The annular body and therefore the first annulus have finite depth from back to front. A light guide is placed immediately behind the iris blades and defines a channel that is open at its back and its front and has a reflective interior surface, with the open back being transversely coincident to the light source so that light from the light source can travel through the channel to and out from the open front.
