aperture mask

Definitions

Computing

  • noun a mask used in colour monitors to keep the red, green, and blue beams separate

Electronics

  • In a picture tube with a three-color gun, a grill with round holes that is placed behind the screen to make sure that each color beam strikes the correct phosphor dot on the screen. It insures, for instance, that the electron beam intended for the red phosphor dots only hits those. Also called shadow mask, or mask (3).
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