The light passing through the holes was converted into electricity, and the image was reassembled at the receiving end with the help of a similar disk spinning at a synchronized rate. By the time the disk made one complete turn, it had covered the entire image. (See illustration on page 10.) As the disk rotated, each hole in succession swept over one horizontal slice of the image, letting through varying amounts of light. The first one, invented in 1883 by Paul Nipkow of Germany, was to focus a small image near the edge of a much larger disk with a spiral pattern of holes punched in it. All these problems were solved fairly reliably by the 1920s, and if it weren’t for step 4-scanning the image many times per second-we could have had viable commercial television when radio was still in its infancy.Īs different television systems competed for supremacy, fast scanning turned out to be the key technological battleground.
Step 3 can be achieved in various ways phosphorescent materials, like the ones that coat today’s picture tubes, were eventually found to work best. Step 2 follows directly from radio voice transmission. The first such substance to be discovered was selenium, in the 1870s, and while it didn’t work out for television, others eventually came along that did. Step 1 requires a substance that converts light into electrical impulses. The main elements of the problem shaped up as follows: (1) breaking an image into tiny dots of varying brightness and encoding those dots into an electrical signal, (2) transmitting the signal, (3) changing the signal back into dots of light at the other end, and (4) repeating the process dozens of times per second. I’ve already perfected color television.īY 1940 ENGINEERS HAD SPENT more than half a century groping toward the electrical transmission of black-and-white (monochrome) images. Finally he stood and addressed his older colleagues. As a panel chairman on the National Television System Committee (NTSC), he had squirmed in his seat for weeks listening to debates over the merits of the various black-and-white systems available at the time. The voice belonged to Peter Goldmark, CBS’s Hungarian-born Wunderkind, who had emigrated to the United States only seven years before. IN AUGUST 1940, AS AN INDUSTRY COM mittee wrestled with transmission standards for television, a young, accented voice momentarily disrupted the rush toward commercial broadcasting.
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