TV MIRRORS “SEE” ONLY ONE COLOR (Dec, 1950)
TV MIRRORS “SEE” ONLY ONE COLOR
IF YOU would like a mirror that reflects your favorite color and no other, the men to see are the color-television specialists of the Westinghouse Research Laboratories. By depositing ultrathin layers of metallic compounds on clear glass they are able to produce mirrors that reflect only one color—either red, green or blue.
The mirrors are used at both the transmitting and receiving ends of their color-television system. At the transmitting end they pick up the color picture and break it down into its three basic colors — red, blue and green — which are sent in the proper sequence. At the receiving end another set of mirrors “gather” the colors for the picture.
To make one-color mirrors, a clear sheet of glass, photo A, is placed in a big glass-jar “oven” surrounded by a wire cage. This is lowered as shown in photo B, sealed, and evacuated of air. Special metal compounds are heated until they evaporate, and as the vapors rise in the jar they strike the glass sheet to apply a smooth, even coaling. The thickness and number of layers deposited on the glass determine which color the mirror reflects.
The research scientist in photo C is studying how colors change under the influence of electricity. The telescope-like device can produce all colors of the rainbow by changing the voltage applied to a light beam.