Patent ID: 6967443

Claim:
A light source comprising: a lamp envelope made of a light transmissive material, wherein the envelope has an ellipsoidal portion disposed centrally between tubular portions disposed on opposite ends of the ellipsoidal portion; a filament centrally disposed within the envelope; an infrared reflective filter coating disposed on at least a portion of the lamp envelope in surrounding relation to the filament, the infrared reflective filter coating having alternate layers of respective high and low refractive indices for selectively passing desired radiation therethrough and reflecting unwanted radiation to the filament; a totally reflecting coating for eliminating infrared loss at wide angle bulb positions disposed on opposite ends of the envelope in surrounding relation to the filament, the totally reflecting coating subtending an angle of approximately 45° and less measured from an axis aligned with the filament for reflecting radiation that would otherwise pass through the infrared reflective filter coating and increasing the efficiency of the light source during continuous operation.