As a 14 year old farm boy plowing his family's fields in Rigby Idaho, Philo T. Farnsworth of was thinking of electron beams and Einstein's theory of relativity. He science teacher recognized that Philo had an unusual intellect and helped him learn as much about science as he could. As he plowed his fields he concieved of drawing a picture with an electron beam just like he was plowing the field, one line at a time, from top to botton and side to side.
After two years of high school, and after finishing two years of college at Brigham Young University, he turned to designing his television system, including an electronic camera, a transmitter, a reciever, and a screen. By 1927 he had built the components of his sytem and successfully demonstrated them to investors. He filed a patent on the working system in 1927.
The problem was that Russian immigrant Vladimir Zworykin was working on the same problem, and filed a patent on parts of his system in 1923. However, his device did not work. Zworykin worked for RCA, and in later years as Farnsworth technology developed, RCA used Zworkykin's filing date as the basis of its claim that RCA should not have to pay royalties to Farnsworth. Farnsworth's patent issued in 1930, and that same year Zworykin visited Farmsworth's lab and was heard to say "I wish that I might have invented it." However, RCA claimed that Zworykin's Iconoscope preceded Farnsworth.
Both sides presented their case for priority to the U.S. Patent Office in a proceeding called an Interference. Farnsworth's evidence for priority of invention was ruled clear evidence of earliest conception.
However, during WWII the government suspended development of television, and by the time the war was over Farnsworth's patents were almost expired.