An aperture grille is one of two major technologies used to manufacture cathode ray tube (CRT) televisions and computer displays; the other is shadow mask.
Fine vertical wires behind the front glass of the display screen separate the different colors of phosphors into strips. Depending on the size of the display, one or two horizontal stabilizing wires are also used, and may be visible as fine lines across the face of the screen, providing the easiest way to distinguish aperture grille and shadow mask displays at a glance. 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.
The first patented aperture grille televisions were manufactured by Sony under the Trinitron brand name, which the company carried over to its line of CRT computer monitors. Subsequent designs, either licensed from Sony or manufactured after the patent's expiry, tend to use the -tron suffix, such as Mitsubishi's DiamondTron and ViewSonic's SonicTron.
While many considered aperture grille technology to produce superior images, advances in shadow mask and hybrid technologies since the 1990s have made people's preferences more a matter of personal choice or specific application. The arrival of inexpensive liquid crystal display (LCD) monitors and other flat-screen designs now challenges both aperture grille and shadow mask CRTs' long reign as the technology behind the screens we look at.