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 in the late 1960s 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.

One significant drawback to the use of aperture grille monitors are the faint lines that appear at 1/3rd and 2/3rds of the screens' height (often at just one location—usually 2/3rds—on smaller displays). These lines are caused by two thin wires that run perpendicular to the grille and are used to maintain equal spacing between the vertical wires of the grille. Enhancements of the technology have reduced the visibility of these lines so that they are almost unnoticeable on modern displays. Users who do notice the faint traces tend to quickly become accustomed to the lines, and soon end up ignoring them. However, a keen eye can still easily still spot the lines.

External links

• Why the lines on my monitor?
• Aperture grille details