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Chris Burden
«C.B.T.V. (Chris Burden Television)»
The theory behind television, or the instantaneous transmission of a moving image from one place to another, was known for sixty years before it was physically possible to demonstrate it. In 1924, John L. Baird, a Scottish inventor, succeeded in transmitting shadowy images from one room to another in his home.
Baird's primitive television was mechanical rather than electronic, and employed a rapidly revolving metal disk, perforated with a spiral of holes. Each tiny hole in the disk was able to scan a single line of the picture area. Behind the disk, a condenser lens focused the light passing through the hole on to a single photo electric cell. The photo electric cell could turn on and off very rapidly, corresponding to areas of light and dark. Thus, the image area was «scanned,» or broken down into a discreet number of on and off electronic impulses. The image could be reconstructed when these impulses were transmitted and decoded by a similar mechanism some distance away.
per minute or 20 times each second. There are 45 holes in the disk. Each hole passes the picture area in approximately 1 /1000 of a second. During this time (1 /1000 of a second), the photo cell must turn on and off 50 times. This, in Order that each scan line is broken down into a series of on-off signals. Thus, the photo cell turns on and off 50,000 times per second or 50 Khz.
This on-off signal is sent down the wire or converted into a radio wave. The receiver is almost an exact copy of the camera. A very special light is turned on and off at 50 Khz by the signal originating in the camera. lf the disk in the receiver is turning at the exact same speed and the corresponding hole (i.e., hole #1 in the camera - hole #1 in the receiver) passes the screen area (the flashing neon plate in the receiver) at the same time as the camera, you are able to reconstruct the image originating in the camera.
I believe that as a technological invention this apparatus is of extreme significance, as it is a most successful solution to man's historic desire to «see beyond» his immediate surroundings. As technology becomes more and more complex, fewer and fewer people have any understanding of how anything really works. By reduplicating and demonstrating this apparatus in its original «simple» form, I hope to aid people in understanding this complex instrument, which has made instant visual communication possible.
(Chris Burden, Beyond the Limits, ed. by Peter Noever, MAK, Ostfildern: Cantz 1996, S. 172f.)
Chris Burden