The company operated internationally: in Britain and Germany in the early 1930s, and then in Britain and America in the late 1930s. Their innovative optical-mechanical television systems produced large screen high-definition pictures for both the home and cinema. Scophony was one of the most highly original television manufacturers of the 1930s. The Scophony company no longer exists either. Sadly, none of the TV sets this motor is designed to fit exist today. (Joshua Sieger papers, Science Museum Group collection) This image shows precisely where the high speed scanner motor was positioned in the set. The motors turned a 20-sided stainless steel mirror drum (visible at the top of the unit) at 30375 RPM to reproduce live 405 line pictures being broadcast by the BBC. It actually consists of 2 motors running on the same shaft, a standard induction motor to bring the unit up to speed, and a phonic motor (in reality another synchronous motor, but designed to work with high frequencies) which was synchronised to the line pulses of the incoming signal. A diagram photocopied from a 1938 Scophony advertising booklet. This light was then modulated (controlled) by a Jeffree cell, and scanned across the screen by 2 mirror drums, a small high speed one like this to produce the line scan, and a large slow speed unit to produce the frame scan (12 mirrors rotating at 250rpm). To get a large bright picture, Scophony engineers developed a revolutionary projection system using a high intensity mercury vapour lamp. In the 1930s, television picture tubes (cathode ray tubes) were mainly small and dim, and only suitable for viewing in low light levels. Scophony model 123 high speed scanner motor © Science Museum Group collection. Our line scanning motor and mirror is from a 1938 Scophony optical-mechanical projection television set. What is a high speed scanner motor and how does it work? For one thing, it was a part of the best television made in Britain prior to the Second World War. Generally speaking, we don’t collect electronic parts however, this object is an exception for a number of reasons.Īs I investigated its history further, I discovered that it had a fascinating background. Iain Baird reveals the technology behind our latest television collection acquisition, and explains why the Scophony television scanner is not to be scoffed at.Īt the end of last year I purchased a 1938 electric motor and mirror drum for our collection from a private collector.
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