Scophony
Encyclopedia
Scophony was a sophisticated mechanical television
system developed in Britain
by Scophony Limited, which used mirrors mounted on high-speed rotating drums to project an image upon a screen.
The company Scophony Limited was established by entrepreneur Solomon Sagall in the early 1930s to exploit the patents of inventor George William Walton. In 1932 Ferranti
invested £3,500 in the company, however in 1934 Ferranti turned down the option to invest a further £10,000 to re-structure Scophony Limited, and in 1935 EKCO
replaced Ferranti as the company's main investor.
In 1938 the Scophony company demonstrated three types of 405 line mechanical television receivers at the Radiolympia exhibition in London: a home receiver, with a picture area of approximately 24" x 22" and two systems intended for theater operation, one producing a 6ft x 5ft image and the other a 9ft x 12ft image.
Several of the theater systems were installed and operated successfully but none of the receivers were sold as production was halted due to the impending war.
Scophony's system used several innovative devices:
Mechanical television
Mechanical television was a broadcast television system that used mechanical or electromechanical devices to capture and display video images. However, the images themselves were usually transmitted electronically and via radio waves...
system developed in Britain
Great Britain
Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...
by Scophony Limited, which used mirrors mounted on high-speed rotating drums to project an image upon a screen.
The company Scophony Limited was established by entrepreneur Solomon Sagall in the early 1930s to exploit the patents of inventor George William Walton. In 1932 Ferranti
Ferranti
Ferranti or Ferranti International plc was a UK electrical engineering and equipment firm that operated for over a century from 1885 until it went bankrupt in 1993. Known primarily for defence electronics, the Company was once a constituent of the FTSE 100 Index but ceased trading in 1993.The...
invested £3,500 in the company, however in 1934 Ferranti turned down the option to invest a further £10,000 to re-structure Scophony Limited, and in 1935 EKCO
EKCO
EKCO from Eric Kirkham Cole Limited was a British electronics company producing radio and television sets from 1924.Expanding into plastic production for its own use, Ekco Plastics produced both radio cases and later domestic plastic products; the plastics company became Lin Pac Mouldings...
replaced Ferranti as the company's main investor.
In 1938 the Scophony company demonstrated three types of 405 line mechanical television receivers at the Radiolympia exhibition in London: a home receiver, with a picture area of approximately 24" x 22" and two systems intended for theater operation, one producing a 6ft x 5ft image and the other a 9ft x 12ft image.
Several of the theater systems were installed and operated successfully but none of the receivers were sold as production was halted due to the impending war.
Scophony's system used several innovative devices:
- A split focus optical system invented by Walton, developed specially for use with mirror scanning systems. Light beams were focused by crossed cylindrical lenses, concentrating the light in two planes. This allowed the use of smaller lenses and mirrors, thus reducing size and cost. This was particularly important to Scophony since they intended to produce extremely large images.
- A light modulator developed by J.H. Jeffree in 1934 and known as the Jeffree cellJeffree cellThe Jeffree cell was an early acousto-optic modulator, best known for its use in the Scophony system of mechanical television. It was invented by J.H...
, a cell filled with a transparent fluid which used mechanical oscillations to modulate the light beam passing through it. It was a substantial improvement over the previous Kerr cell, 200 times as much modulated light being available at the screen.
- High speed synchronousSynchronization (alternating current)-Electricity generation:Electricity generation requires the connection of large numbers of alternators in parallel and additional alternators must be switched in when demand rises....
motors which could be relied on for 1000 hours of use, some lasting longer without noticeable wear. The Scophony system used two: a low speed scanner which operated at 240 RPM and a high speed scanner which ran at 30,375 RPM for 405 line transmissions or 39,690 RPM for the American 441 line system.