Color Tele Goes Big (Jul, 1947)

Color Tele Goes Big

COLOR television that can be projected on a large screen is the latest achievement of RCA engineers. At a demonstration in a large auditorium, color images were received and shown on a 7-1/2- by 10-foot screen. The new receiver-projector utilizes the all-electronic system of color transmission (PSM, Feb. ’47, p. 100) in which three separate images in red, green and blue are sent out simultaneously over adjoining channels.

At the receiver, each image is picked up by a separate kinescope and focused onto a concentric mirror that reflects the picture back to the screen. Correcting lenses compensate for mirror distortion, so the three pictures reach the screen in proper focus and proper register.

Although color and picture quality are good, images do not have the brightness and definition achieved by black-and-white receivers. RCA experts say several years will be needed to bring color television up to present monochrome standards.

Because of the cost of three-part receivers and the delicate optical system necessary when using large-screen equipment, the new system is better suited to industrial plants and theaters than the home.

4 comments
  1. DrewE says: October 26, 201210:26 am

    Wouldn’t you need a parabolic mirror, rather than a spherical one? I’m actually a little surprised they used a reflector design at all if image brightness was a major concern; a refractive system would seem to me to be more efficient, given the necessary light loss from the central portion of the reflector due to occlusion by the projector tube. A refractive design would probably be larger, and quite possibly heavier and more expensive.

  2. Hirudinea says: October 26, 20123:28 pm

    The projectors look like reflector telescope in reverse, dosen’t it?

  3. jayessell says: October 26, 20124:19 pm

    This is the principle of the projector TVs of the 1980s.
    3 projector CRTs aimed and a semi parabolic screen.
    The ones I saw were never in perfect registration.
    And yes… Somewhat like a Newtonian telescope.
    Schmidt-Cassegran? That uses spherical components.

  4. quadibloc says: December 16, 20123:37 am

    The optical system here is that of the Schmidt camera, as there’s no secondary mirror. And the curved face of the picture tube makes up for the Schmidt’s one weakness, a curved field.

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