Electronic Television

The first man to envision an electronic television system was a British electrical engineer named A. Cambell Swinton. In a speech he gave in 1911, Swinton described a design using cathode-ray tubes to both capture the light and display an image. A cathode-ray tube was a glass bottle with a long neck on one end and a flattened screen on the other. The bottle was pumped clear of air so that an "electron gun" in the neck could shoot a stream of electrons toward the flattened end of the tube which was covered with a coating of phosphor material. When the electrons hit the material it would glow. By sweeping the electron stream back and forth in rows from top to bottom and varying the intensity of the stream, Swinton reasoned, an image could be drawn in the same manner that Nipkow's disks did.

A modified version of the tube could also be used as a camera. If the flattened end could be given a sandwich of metal, a non-conducting material and a photoelectric material, light focused on the flattened end with a lens would produce a positive charge on the inside of the surface. By sweeping the electron stream across the flattened end, again in rows, the charges could be read and the image could be turned into a signal that could be sent to the display screen to be seen.

Swinton's idea almost exactly describes the way modern electronic television works. While his forevision was near perfect, Swinton, nor anyone else at the time, knew how to actually engineer such a system and make it work. An electronic system, if it could be made to work, however, would operate at much faster speeds than any mechanical system could and would allow the picture to be composed of more rows, therefore increasing the quality of the image.

It was eleven years after Swinton's lecture that a teenager from Utah became interested in electronic television. Philo T. Farnsworth had read about Nipkow's disc system and decided it would never produce a high quality picture. After experimenting with electricity, he declared to one of his high school teachers that he thought he could devise a better system. He proceeded to lay it out for the surprised man on the classroom blackboard. The teacher encouraged Farnsworth and Farnsworth set out to California to build a laboratory where he could experiment with his ideas. Working in darkened rooms in Los Angeles and later San Francisco, Farnsworth kept his work so secret that his laboratory was once the subject of a raid by police, who thought that he was using a still to produce illegal alcoholic beverages.

By September of 1927 Farnsworth was transmitting a sixty line picture from camera to screen using an entirely electronic system. It was at this point in time his work drew the attention of David Sarnoff. Sarnoff was chief of the Radio Corporation of America (RCA): the leader in supplying radios and radio parts to the United States.

Many of RCA's radio patents would soon expire, so Sarnoff was searching for another market he could corner and television was the obvious choice. After hiring Vladimir Zworykin, a Russian immigrant who had been experimenting with mechanical television for a decade, Sarnoff sent him to California to look at Farnsworth's work. Later Sarnoff would visit Farnsworth's laboratory himself.

Sarnoff and Zworykin quickly realized the value of Farnsworth's invention and Sarnoff tried to buy the young man out for $100,000. Farnsworth, thinking he could make more in collecting patent royalties from RCA than selling his invention to them, refused. Sarnoff, miffed, said, "Then there's nothing here we'll need" and sent Zworykin off to build their own version of the technology.

Farnsworth's designs kept showing up in Zworykin's work and lawsuits between the two companies followed. Eventually RCA was forced to pay Farnsworth $1,000,000 in licensing fees, but the onset of WW II delayed the introduction of television to most of the United States and the market for electronic television did not really take off until after the war. By then many of Farnsworth's key patents had expired and he never made the money he probably really deserved for his contributions to electronic television.