An illumination system includes optics capable of adjusting the size of a beam of light and adjusting the focus of the beam of light. Spot size control optics adjusts the overall size of the beam of light and separately adjusts the ellipticity of the beam, primarily in one dimension. Light from the spot...http://www.google.de/patents/US6426840?utm_source=gb-gplus-sharePatent US6426840 - Electronic spot light control
