Vladimir K. Zworykin

Vladimir Kosma Zworykin (1888/1889 – July 29, 1982) was a Russian-American inventor, engineer, and pioneer of television technology. Zworykin invented a television transmitting and receiving system employing cathode-ray tubes. He played a role in the practical development of television from the early thirties, including charge storage-type tubes, infrared image tubes and the electron microscope.

Early life and education Vladimir Zworykin was born in Murom, Russia, in 1888 or 1889, to the family of a prosperous merchants. He had a relatively calm upbringing, and he rarely saw his father except on religious holidays. He studied at the St. Petersburg Institute of Technology, under Boris Rosing. He helped Rosing with experimental work on television in the basement of Rosing's private lab at the School of Artillery of Saint Petersburg. They worked on the problem of "electrical telescopy," something Zworykin had never heard of before. At this time, electrical telescopy (or television as it was later called) was just a dream. Zworykin did not know that others had been studying the idea since the 1880s, or that Professor Rosing had been working on it in secret since 1902 and had made excellent progress. Rosing had filed his first patent on a television system in 1907, featuring a very early cathode-ray tube as a receiver, and a mechanical device as a transmitter. Its demonstration in 1911, based on an improved design, was the world's first demonstration of TV of any kind. Zworykin married Tatiana Vasilieva in 1916, they had two daughters (the couple separated in the early 1930s).

Career Zworykin graduated in 1912. He then studied X-rays under professor Paul Langevin in Paris. During World War I, Zworykin was enlisted and served in the Russian Signal Corps. He then worked testing radio equipment that was being produced for the Russian Army. Zworykin left Russia for the United States in 1918 during the Russian Civil War. He left through Siberia, travelling north on the River Ob to the Arctic Ocean as part of an expedition led by Russian scientist Innokenty P. Tolmachev, eventually arriving in the U.S. at the end of 1918. He returned to Omsk, then capital of Admiral Kolchak's government in 1919, via Vladivostok, then to the United States again on official duties from the Omsk government. These duties ended with the collapse of the White movement in Siberia at the death of Kolchak. Zworykin then decided to remain permanently in the United States.

Once in the U.S., Zworykin found work at the Westinghouse laboratories in Pittsburgh where he eventually had an opportunity to engage in television experiments. Zworykin applied for a television patent in the U.S. in 1923. He summarized the resulting invention in two patent applications. The first, entitled "Television Systems", was filed on December 29, 1923, and was followed by a second application in 1925 of essentially the same content, but with minor changes and the addition of a Paget-type RGB raster screen for color transmission and reception. He was awarded a patent for the 1925 application in 1928, and two patents for the 1923 application that was divided in 1931, although the equipment described was never successfully demonstrated. Zworykin described cathode-ray tubes as both transmitter and receiver. The operation, whose basic thrust was to prevent the emission of electrons between scansion cycles, was reminiscent of A. A. Campbell Swinton's proposal published in Nature in June 1908.

The demonstration given (sometime in late 1925 or early 1926) by Zworykin was far from a success with the Westinghouse management, even though it showed the possibilities inherent in a system based on the cathode-ray tube. He was told by management to "devote his time to more practical endeavours," yet continued his efforts to perfect his system. As attested by his doctoral dissertation of 1926, earning him a PhD from the University of Pittsburgh, his experiments were directed at improving the output of photoelectric cells. There were, however, limits to how far one could go along these lines, and so, in 1929, Zworykin returned to vibrating mirrors and facsimile transmission, filing patents describing these. At this time, however, he was also experimenting with an improved cathode ray receiving tube, filing a patent application for this in November 1929, and introducing the new receiver that he named the "kinescope", reading a paper two days later at a convention of the Institute of Radio Engineers. Having developed the prototype of the receiver by December, Zworykin met David Sarnoff, who eventually hired him and put him in charge of television development for the Radio Corporation of America (RCA) at its factories and laboratories in Camden, New Jersey. The move to the RCA's Camden laboratories occurred in the spring of 1930, and the difficult task of developing a transmitter could begin. There was an in-house evaluation in mid-1930, where the kinescope performed well (but with only 60 lines definition), and the transmitter was still of a mechanical type. A "breakthrough" would come when the Zworykin team decided to develop a new type of cathode ray transmitter, one described in the French and British patents of 1928 priority by the Hungarian inventor Kálmán Tihanyi whom the company had approached in July 1930, after the publication of his patents in England and France. This was a curious design, one where the scanning electron beam would strike the photoelectric cell from the same side where the optical image was cast. Even more importantly, it was a system characterized by an operation based on an entirely new principle, the principle of the accumulation and storage of charges during the entire time between two scansions by the cathode-ray beam.

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