Main Page | See live article | Alphabetical index

Vladimir Zworykin

Vladimir Kosma Zworykin (1889-1982) is a pioneer of television.

Zworykin invented the iconoscope, a television transmitting tube and the kinescope, a cathode ray tube that projects pictures it receives onto a screen. He also invented an infrared image tube and helped develop an electron microscope.

Zworykin was cursed with living in interesting times, born in Russia in 1889, he studied at the St. Petersburg Institute of Technology. He was eventually hired by one of his instructors, Boris Rosing, who was seeking ways of extending mans vision. By 1907 Rosing had developed a television system which employed a mechanical disc system as a camera and a glass tube (cathode ray tube) as a receiver. The system was primitive but it was more electronic than mechanical. With the Russian Revolution, Rosing went into exile and died. Zworykin carried on his work.

With the outbreak of World War I, Zworykin decided to leave Russia for the United States. Zworykin found work with Westinghouse. Based on their pioneering efforts in radio, he tried to convince them to do research in television. Turning down an offer from Warner Brothers, Zworykin worked nights, fashioning his own crude television system. In 1923, Zworykin demonstrated his system before officials at Westinghouse and applied for a patent. All future television systems would be based on Zworykin's 1923 patent. Zworykin describes his 1923 demonstration as "scarcely impressive".

Westinghouse officials were not prepared to base an investment in television on such a flimsy system. The company's suggestion was that Zworykin devote his time to more practical endeavours. Undeterred, Zworykin continued in his off hours to perfect his system. He was so persistent that the laboratory guard was instructed to send him home a 2:00 in the morning if the lights of the laboratory were still on. During this time,. Zworykin managed to develop a more sophisticated picture tube called the Kinescope, which serves as the basis of the television display tubes in use today.

In 1929, Vladimir Zworykin invented the all electric camera tube. Zworykin called his tube the Iconoscope (literally "a viewer of icons"). He demonstrated both the iconoscope and kinescope to the Institute of Radio Engineers. Zworykin's all electronic television system demonstrated the limitations of the mechanical television system. In attendance was David Sarnoff who eventually hired Zworykin to develop his television system for RCA.

Under Sarnoff's watchful eye, Zworykin continued to develop the electronic system. When Zworykin started at RCA his system was scanning 50 lines. Experimental broadcasts started in 1930 first using a mechanical camera transmitting at 120 lines. By 1933 a complete electronic system was being employed with a resolution of 240 lines. Zworykin had originally told Sarnoff it would cost $200,000 to develop a television system, the final cost was estimated to cost RCA about $50,000,000. Zworykin was not alone. By 1934 two British electronic firms, EMI and Marconi, created an all-electronic television system. They used the Orthicon camera tube invented by an American company, RCA. This electronic system was officially adopted by the BBC in 1936. It consisted of 405 scanning lines, changing at twenty five frames per second.