Nothing new 1: Video discs (1907)

by royalpavilion

I’ve just been reading the 1907 patent for the device that became known as the Spirograph. It was a disc, packaged rather like a 78rpm audio record, that carried a spiral of microscopic images. It was invented by a British media journalist, a precursor of mine. Theodore Brown edited the Kinematograph and Lantern Weekly; I edit Screen Digest. I’ve never invented anything as far as I can recall.

brown_spirographMr Brown was quite a prolific inventor, mainly of mechanical toys, puzzles, games, kaleidoscopes and advertising devices that used changing images or patterns to attract attention. Some of his patents were held jointly with his wife, Bessie Kate Brown. Indeed, for the ‘spirograph’ her name precedes his and she gives her occupation as ‘lady’. However, unlike some pictures promoting home cinema at that time, she was not shown turning the handle to show just how easy it was to use.

The images were reduced through a microscope lens system from 35mm film to form a series of tiny images in a spiral around the disc. That makes it a proto-video disc. The advantage of a disc, of course, it that it can be copied easilywithout having to spool through film or tape.

I first saw this device, or something like it, in 1980 in the Smithsonian in Washington DC but never managed to trace much information about it. Now, courtesy of the excellent European Patent Office site, I can read exactly what Brown had in mind. Which turns out to be even more like a video disc than I realised. As well as (or more accurately, instead of) forming a spiral on the disc, the images can be in the form of concentric rings, with the mechanism moving over by one ring at the end of each revolution. However, as Brown points out, if the disc does not advance, the images can go on repeating themselves. In principle this is exactly the same as the concept used in the Philips VLP/MCA Discovision of the mid 1970s. Discs could be mastered with either constant linear velocity, in which the laser follows the spiral track at a constant rate (the rate of rotation reducing as the laser moves towards the outer edge of the disc), or constant angular velocity, in which the disc rotates at a constant speed and each revolution carries one frame of picture. So if the disc is held on a given revolution, the image on the screen is frozen.

What goes around, comes around.

TTFN

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