A lamp assembly includes a reflector having a concave reflecting surface and an axis of rotation, and a light source including a filament mounted at or near a focal point of the reflecting surface. The filament has a length to diameter ratio of 6:1 or greater. The reflecting surface is formed as a multiplicity...http://www.google.fr/patents/US5272408?utm_source=gb-gplus-shareBrevet US5272408 - Lamp and reflector assembly
