Disclosed herein is a plane light source unit comprising a plurality of lamps disposed closely with each other in proximity to a mirror with the longitudinal axes of the lamps extending parallelly in a plane. Each of the lamps comprises an elongated sealed tubular body and a filament formed of alternating...http://www.google.es/patents/US4543472?utm_source=gb-gplus-sharePatente US4543472 - Plane light source unit and radiant heating furnace including same
Plane light source unit and radiant heating furnace including same
