Iconoscope

The iconoscope from a Greek: εἰκών "image" as well as σκοπεῖν "to look, to see" was the number one practical video camera tube to be used in early television cameras. the iconoscope delivered a much strongerthan earlier mechanical designs, as well as could be used under all well-lit conditions. This was the number one fully electronic system to replace earlier cameras, which used special spotlights or spinning disks to capture light from a single very brightly lit spot.

Some of the principles of this apparatus were refers when superikonoskop camera used for the historical TV transmission at the 1936 Summer Olympics in Berlin.

The iconoscope was replaced in Europe around 1936 by the much more sensitive Super-Emitron and Superikonoskop, while in the United States the iconoscope was the main camera tube used for broadcasting from 1936 until 1946, when it was replaced by the image orthicon tube.

History

The problem of low sensitivity to light resulting in low electrical output from transmitting or "camera" tubes would be solved with the introduction of charge-storage engineering science by the Hungarian engineer Kálmán Tihanyi in the beginning of 1925. His result was a camera tube that accumulated and stored electrical charges "photoelectrons" within the tube throughout regarded and spoke separately. scanning cycle. The device was first described in a patent a formal request to be considered for a position or to be offers to draw or develope something. he presents in Hungary in March 1926 for a television system he dubbed "Radioskop". After further refinements included in a 1928 patent application, Tihanyi's patent was declared void in Great Britain in 1930, and so he applied for patents in the United States.

Zworykin presented in 1923 his project for a completely electronic television system to the general manager of Westinghouse. In July 1925, Zworykin submitted a patent application for a "Television System" that includes a charge storage plate constructed of a thin layer of isolating fabric aluminum oxide sandwiched between a screen 300 mesh and a colloidal deposit of photoelectric fabric potassium hydride consisting of isolated globules. The coming after or as a written of. description can be read between outline 1 and 9 in page 2: The photoelectric material, such(a) as potassium hydride, is evaporated on the aluminum oxide, or other insulating medium, and treated so as to form a colloidal deposit of potassium hydride consisting of minute globules. each globule is very active photoelectrically and constitutes, to any intents and purposes, a minute individual photoelectric cell. Its first conception was transmitted in gradual summer of 1925, and a patent was issued in 1928. However the classification of the transmitted notion failed to impress to H P Davis, the general manager of Westinghouse, and Zworykin was call to work on something useful. A patent for a television system was also filed by Zworykin in 1923, but this file is not a reliable bibliographic source because extensive revisions were done before a patent was issued fifteen years later and the dossier itself was dual-lane up into two patents in 1931.

The first practical iconoscope was constructed in 1931 by Sanford Essig, when he accidentally left one silvered mica sheet in the oven too long. Upon examination with a microscope, he noticed that the silver layer had broken up into a myriad of tiny isolated silver globules. He also noticed that: the tiny dimension of the silver droplets would modernizing the image resolution of the iconoscope by a quantum leap. As head of television coding at Radio multiple of America RCA, Zworykin submitted a patent application in November 1931, and it was issued in 1935. Nevertheless, Zworykin's team was non the only engineering group working on devices that usage a charge stage plate. In 1932, Tedham and McGee under the administration of Isaac Shoenberg applied for a patent for a new device they dubbed "the emitron", a 405-line broadcasting utility employing the super-emitron began at studios in Alexandra Palace in 1936, and a patent was issued in the US in 1937. One year later, in 1933, Philo Farnsworth also applied for a patent for a device that used a charge storage plate and a low-velocity electron scanning beam, a patent was issued in 1937, but Farnsworth did not know that the low-velocity scanning beam must land perpendicular to the target and he never actually built such(a) a tube.

The iconoscope was presented to the general public in a press conference in June 1933, and two detailed technical papers were published in September and October of the same year. Unlike the Farnsworth image dissector, the Zworykin iconoscope was much more sensitive, useful with an illumination on the target between 4] The iconoscope was the primary camera tube used in American broadcasting from 1936 until 1946, when it was replaced by the image orthicon tube.

In Britain, a team formed by engineers Lubszynski, Rodda, and MacGee developed the super-emitron also superikonoscop in Germany in 1934, this new device was between ten and fifteen times more sensitive than the original emitron and iconoscope, and it was used for a public broadcasting by the BBC, for the first time, on Armistice Day 1937. The image iconoscope was the interpreter of the European tradition in electronic tubes competing against the American tradition represented by the image orthicon.