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.

5 comments
  1. Torgo says: November 14, 20083:08 am

    Was there ever a successful color TV system that worked this way?

  2. David Moisan says: November 14, 200810:46 pm

    Those dichroic mirrors were and are used in broadcast cameras up to the present day! Any three-chip camera will have dichroic prisms, same thing.

    I think the guy playing with the color changing optics has reinvented LCD’s.

  3. jayessell says: November 15, 20089:26 am

    On the receiving end, the 3 chip DLP video projectors must use dichroic mirrors/prisms to combine the images before they enter the lens.
    45 kilobucks!?!

    Single chip DLP units use a rotating color wheel to produce the colors in rapid succession.

    The microscopic wobbling mirrors don’t wear out.
    Thanks Nanotechnology!

  4. Anthony says: December 8, 20088:02 pm

    For the “C” panel, it needs a warning, “Do not use telescope-like device with remaining eye!”

  5. Jeff says: August 31, 20107:56 pm

    The color TV cameras used on the Apollo lunar missions used a rotating color wheel.

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