A bimodal traffic replacement light for fitting within an existing housing of a traffic signal, the replacement light fitted with light emitting diodes, the replacement light providing for lighting the diodes in the full diode field or selectively lighting a number of diodes in the field to form a shape...http://www.google.es/patents/US7307546?utm_source=gb-gplus-sharePatente US7307546 - Bimodal replacement traffic light
