A nonimaging optical system for processing a first and second light distribution. The nonimaging optical system includes at least two refractive surfaces, at least one reflective surface nearer to the first light distribution along at least one ray path than the nearer of the two refracting surfaces...http://www.google.es/patents/US7068446?utm_source=gb-gplus-sharePatente US7068446 - Compact non-imaging light collector
