A monitor is used to display images from the computer. Monitors are important because they are what users interact most with.

When talking about monitors, there are two basic kinds: cathode ray tube (CRT) or flat panel. A CRT monitor works exactly like a television screen.

In the rear of the monitor's housing is an electron gun. The gun directs a beam of electrons through a magnetic coil, which aims the beam at the front of the monitor. The back of the monitor's screen is coated with phosphors (chemicals that glow when struck by electrons). The screen's phosphor coating is organized into a grid of dots. The smallest of these dots is named a pixel (from PICture ELement).

To compose the image displayed on the screen, the electron gun systematically aims electrons on all the pixels on the screen. In a color monitor, the only difference is that there are three electron guns. One for each color (RGB). Although the beams are colorless, the phosphors they hit are aranged in triangles. The combination of these three phosphors make a color pixel.

When Buying a CRT Monitor

• Size
• Resolution
• Refresh Rate
• Dot Pitch

The physical size of a picture tube dirrectly affects how well you can see something. With a larger monitorr, you can make images on the screen look larger, or you could create more work space. Monitors, like televisions are measured diagonally. The picture is samller than the measurement because of the inability to display images in the exact corners.

The resolution of a monitor is classified by the number of pixels on the screen, and is expressed in matrix form. To display at a higher resolution, a more expensive monitor, and more expensive adapter is needed.

A refresh rate is the number of times per second that the electron gun can scan every pixel on the screen. This measurement is expressed in hertz (Hz), or cycles per second. A refresh rate is important, because phosphors fade quickly after the electrons have passed over it. If your monitor has a slow refresh rate you may notice a flicker.

Another important factor is dot pitch. Dot pitch can be defined as the distance between phosphors of a single pixel. The dot pitch of a monitor should be no less than .28 mm.

The quality of the images displayed depends as much on the video adapter as it does on the monitor. A video adapter has its own dedicated memory so that the processing is on the card itself. Today, many manufacturers are making 3D accelerators. These accelerator allow users to render graphics more quickly and more complex.

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