Pioneers of Television
John Logie Baird (1888–1946)
The achievements of Scottish-born inventor John Logie Baird have been committed to a separate section on this site available to view by clicking here.
Vladimir Kosma Zworykin (1889–1982)
In 1923, Vladimir Kosma Zworykin — who trained under Rosing — filed patent application No. 2,141,059 for his 'Iconoscope'. It was the first practical television transmission tube. A demonstration given by Zworykin at the University of Pittsburgh in 1925 showed the inherent possibilities of the Braun tube system. His work on photoelectric cells earned him a PhD in 1926.
After experimenting with an improved cathode ray tube, he filed a patent application in November 1929 for his new receiver which he named 'Kinescope' and introduced it two days later at a convention of the Institute of Radio Engineers. Zworykin soon met David Sarnoff, who employed him in spring 1930 to take charge of television development for RCA in New Jersey.
Zworykin's Kinescope performed well but transmission was still of a mechanical nature. He visited Philo Farnsworth's laboratory in the same year where he was so impressed by Farnsworth's Image Dissector that he incorporated many of its features into his own designs at RCA.
After publication of Hungarian inventor Kálmán Tihanyi's patents in 1928, Zworykin's team adopted his patents in 1930 in order to further develop their new CRT transmitter, and in October 1931, their new camera tube was named the 'Iconoscope'. The system was ready by late 1934 and in early 1935 the tube was introduced and further developed in Germany, being one of several cameras used at the Berlin Olympic Games, along with Farnsworth's Image Dissector.
Kenjiro Takayanagi (1899–1990)
In 1925, a young Japanese lecturer called Kenjiro Takayanagi developed a system similar to Baird's using a Nipkow disk. However, Takayanagi took the important step of using CRT technology, creating the first all electronic television set. On Christmas Day, 1925, he demonstrated his system made up of 40 scan lines by broadcasting images of a Japanese katakana character called 'I'.
Charles Francis Jenkins (1867–1934)
On 13th June 1925, Charles Francis Jenkins set up a demonstration in his laboratory in Washington. He received a transmission from the navy radio station NOF in Anacostia. His guests included George K. Bungeso, head of the Bureau of Standards, and William D. Tennell, chief radio expert of the Department of Commerce. They watched a ten-minute broadcast of a Dutch windmill in motion; the image only appeared in silhouette.
In July 1928 he began regular broadcasts of 'silhouette transmissions' from Washington DC using a spinning disc which provided a one-inch square picture with 48 lines of resolution.
Kálmán Tihanyi (1897–1947)
Hungarian Kálmán Tihanyi was working on the theory of television from as early as 1917, but it wasn’t until March 20th, 1926 that he filed a patent application for his fully electronic television system. Although it employed CRT technology, Tihanyi's system represented a radical departure, building upon what would become known as the 'storage principle'. The result was an effective increase in the picture current by a factor that would equal the number of picture elements. In 1928 he filed two more patents for his system in Germany, France, England and the U.S. Tihanyi went to Berlin, where the manufacture of mechanical television had already begun. His invention was met with enthusiasm but both Telefunken and Siemens opted to persue the development of mechanical television.
Philo T. Farnsworth (1906–1971)
In 1927, American inventor Philo Farnsworth formed a research partnership with George Everson in Salt Lake City in order to develop his ideas. He was soon applying for patents in connection with his 'electronic' television, highlighting his belief that a satisfactory image could never be achieved by mechanical means and that his all-electronic system was a much more effective means of broadcasting an image.
On September 7th 1927, at his laboratory at 202 Green Street in San Francisco, Philo Farnsworth transmitted the first image (a simple straight line backlit from a glass slide) from his Image Dissector camera tube. In response to questions from his backers as to when they would begin to see a return on their investments, to their astonishment, he transmitted a dollar sign in a specially staged demonstration in May of the following year and in 1929, he transmitted the first live human images when he transmitted an image of his wife Pem, though the blinding light required meant that she had difficulty opening her eyes.
In 1934, Farnsworth secured interests in Germany and in 1936 his Image Dissector cameras were used to broadcast the Berlin Olympic Games. His company also continued to transmit regular experimental entertainment programmes.
Boris Pavlovich Grabovsky (1901–1966)
Russian Boris Pavlovich Grabovsky, claimed that he made the first electronic broadcast in 1926. He said: 'Pictures of a bright spot were transmitted and the movement of a hand.' However, it is believed more likely that this did not occur until nearer the date of his patent, which was issued on July 30th, 1928.
René Bartholomew (1889–1954)
French engineer René Barthélemy made the first demonstration of his 30 line mechanical system in France at the Higher School of Electricity in Malakoff. He went on to broadcast 60 lines of definition on 26th April 1935 and 180 lines on 2nd December.