metal screen in a cathode ray monitor which reduces the distortion in the displayed picture
The shadow mask is one of two major technologies used to manufacture
cathode ray tube (CRT)
televisions and
computer displays that produce
color images (the other is
aperture grille). Tiny holes in a metal plate separate the colored
phosphors in the layer behind the front glass of the screen. The holes are placed in a manner ensuring that
electrons from each of the tube's three cathode guns reach only the appropriately-colored phosphors on the display. All three beams pass through the same holes in the mask, but the angle of approach is different for each gun. The spacing of the holes, the spacing of the phosphors, and the placement of the guns is arranged so that for example the blue gun only has an unobstructed path to blue phosphors. The
red,
green, and
blue phosphors for each
pixel are generally arranged in a
triangular shape (sometimes called a "
triad"). All early color televisions and the majority of CRT computer monitors, past and present, use shadow mask technology. This principle was first proposed by Werner Flechsig in a German patent in
1938.
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