Better focusing allowed the size of the holes in the shadow mask to increase in proportion to the opaque area, which improved display brightness.
42.
The major disadvantage was the difficultly in correctly focussing the beam on the correct color, a problem RCA solved with their shadow mask system.
43.
The disadvantage of this approach was that for any given amount of gun power, the shadow mask filtered out the majority of the energy.
44.
Stencils are also used in micro / nanotechnology, as miniature shadow masks through which material can be deposited, etched or ions implanted onto a substrate.
45.
Additionally, aperture grille displays tend to be vertically flat and are often horizontally flat as well, while shadow mask displays usually have a spherical curvature.
46.
Problems with doming were addressed through the use of invar shadow masks that were mechanically robust and attached to the tube using a strong metal frame.
47.
A shadow mask is a metal plate punched with tiny holes that separate the colored phosphors in the layer behind the front glass of the screen.
48.
The main purpose of the grille is to ensure that each beam strikes only the phosphor stripes for its color, much as does a shadow mask.
49.
The shadow mask is a thin metal foil with small holes photoetched into it, positioned so the holes lie directly above one triplet of colored phosphor dots.
50.
The shadow mask consists of a thin sheet of steel with tiny holes photo etched into it, placed just behind the front surface of the picture tube.
