Active Matrix
CD switching method using 'active' devices, i.e. TFTs (Thin Film Transistors).

Access Bus
Serial communication protocol allowing a computer host to communicate with external peripherals and on-board devices. Largely superseded by USB.

ADB
Serial port for Apple Macintosh computer.

AGP
Accelerated Graphics Port: High speed internal bus used to transfer data to a computer's graphics card.

AGRAS
(Anti-glare, anti-reflective, anti-static) coating on CRT faceplate to improve the quality of the image.

ANSI
American National Standards Institute: American standards setting body. Standards include some relevant to the display industry.

Aperture Grille
A wire frame strung with thin vertical metal wires located in the picture tube behind the faceplate, ensures electrons from the red gun will only illuminate the red phosphor stripes, similarly for green and blue. Also called a stripe mask. Produces brighter images with richer, more saturated colours.

Auto-sizing
Auto-sizing occurs when a monitor can maintain a constant image size across different video modes. Two common ways of achieving auto-sizing are mode sensing, pre-programmed factory settings and user defined modes (Rosch, 1991). See also GTF

Bandwidth
The capacity of a channel to handle data.

Barrel
A type of distortion in which an image's sides or top and bottom (or both) appear to bulge outward (Rash, 1992).

Bezel
A frame of plastic or metal, fitting around the LCD glass, to protect the edges of the glass.

Blooming
When image brightness increases, the CRT's electron beam tends to spread out and lose focus. This loss of focus in bright portions of an image makes the image appear to expand, or "bloom," and lose detail (Rash, 1992).

Bow
A type of distortion in which opposite sides of the screen image curve in the same direction (Rash, 1992).

Cell
See Subpixel.

Cell Gap
The space containing liquid crystal fluid between the two pieces of glass. (LCD)

Cold Cathode Backlight (CCFT)
In LCD graphic modules, a type of fluorescent backlighting or edge lighting. One or more fluorescent lamps behind the LCD panel that provides the light that is either blocked (black) or passed (white) by the LCD cell.

Contrast Ratio
The difference in luminance between a white square centred on the screen and the black surrounding area.

Convergence
The ability of a CRT monitor to correctly align the red, green and blue components of an image on the screen. Convergence problems are often visible as fringes of colour at the edge of the screen or colour around text or graphics where it should be white (Rash, 1992).

CRT
A cathode ray tube (CRT) is the picture tube used to create images in most desktop monitors. In a CRT, three electron guns shoot electrons at red, green or blue phosphor dots inside the surface of the monitor screen. When the phosphor dots glow red green or blue, an image is produced.