Question: Who invented the first efficient incandescent light bulb that was later used in projectors?
Disambiguated questions and answers: question: Who invented the first efficient incandescent light bulb that was used in projectors?
Who invented the first efficient incandescent light bulb that was later improved and eventually used in projectors?
answer: Koninklijke Philips N.V.
Philips
Thomas Alva Edison
Edison
Thomas Edison
Natural Questions answer: Thomas Edison (from the Wikipedia article "Incandescent light bulb")