Phonovision, 1920s video disc, coloured photograph. This is a standard 78 rpm (revolutions per minute) gramophone disc, used by the Scottish engineer

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Phonovision, 1920s video disc, coloured photograph. This is a standard 78 rpm (revolutions per minute) gramophone disc, used by the Scottish engineer John Logie Baird (1888-1946) to record the output from his television system. The principle is the same as a gramophone, with an electromagnetic needle used instead to detect and convert the indentations on the disc back into light and sound on a television screen. Baird was granted a patent on his Phonovision system in 1928, but the image quality was poor compared to cinemas. Original photograph published in Television (Dinsdale, 1928).

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Size: 4131px × 4310px
Photo credit: © SHEILA TERRY/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No

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