"Edison was legally attributed with most of the inventions produced there, though many employees carried out research and development under his direction. His staff was generally told to carry out his directions in conducting research, and he drove them hard to produce results."

So, when you read "Edison invented such and such", it really means that the people working under him invented such and such. So, it really is similar to the way "Google" is inventing lots of interesting things. The difference is Larry and Sergey refrain from claiming that they personally invented everything that comes out of Google.