This article appears courtesy of Mobile Computing and Communications magazine and Emap-Petersen.

With an active-matrix display, a notebook is able to show off images with great brightness and contrast. Active-matrix screens also offer wide viewing angles and handle the best video output.

Delivering the image - a seemingly complicated process - takes place in the screen itself. In the back panel, a thin fluorescent tube gives off light in all directions. To make the light useful for the display, it passes through a polarizing filter that allows only vertical light to pass through.

The vertical light then passes through two glass layers, which sandwich the liquid-crystal cell. When no current is passing through the liquid crystal, it bends the vertical light 90 degrees, turning it to horizontal light.

On the glass surface are the transistors, which form the pixels that create the image. Each pixel comprises three subpixels; each subpixel is keyed to glow red, green or blue.

In an XGA display, which measures 1,024 pixels by 768 pixels, each pixel will comprise three sub-pixels to form a complete array - yielding a total of 3.1 million transistors. Current passes through the transistors, which deliver it to the liquid crystal.

The pixels can be turned on partially, which alters the current and, thus, the color of the pixel. A color filter then completes the multilayered sandwich that forms the screen, resulting in an image in living color.