Philo T. Farnsworth
He is one of several people who can claim to have invented television.  He invented the picture tube and built the first all-electric TV set.  He had built his first prototype in 1927, and presented it in 1928.  For the next few years, Farnsworth fought a battle with RCA over his patents.  By 1936, he was filming television programs.  He did a lot of research in nuclear fusion.  He also invented the modern method of air-traffic control.