Why Do We Need Windows XP Screensavers?

The screen saver, as the name explains, saves the screen. One may wonder what the thing is from which the screen saver protects the screen. To understand this, we'll have to understand how images are displayed on your computer.

There are three types of displays on the marketL CRT (Cathode Ray Tube) monitors used in older desktops, plasma (used in high end systems for very high quality image editing), and LCD (Liquid Crystal Display) used in notebooks. Although these contain different materials, the basics of producing images are same for all three types (Ref Fig 1 below).

You must have come across the term "resolution" many times. You know that higher resolutions offer better image quality. Other than that, you also consider pixel depth while buying a notebook, digital camera, or HDTV. Greater values of pixel depth offer better clarity and more colors. Notebook display carries pixel depth of "eight" to display millions of colors. However, pixel depth is not related to Windows XP screen savers, so we will stop here!

Coming back to resolutions, if your LCD screen has "1280 by 800" resolution, it means that the entire screen is virtually divided into 1280 horizontal and 800 vertical lines. Each intersection of these lines carries a pixel (also called a dot or point). The pixels may be square (PAL) or rectangular (NTSC, 16:9 for Digital Video in HDTVs). PAL and NTSC are also not related to Windows XP screen savers but as the context came through, I thought of informing you that NTSC pixels offer high quality images than PAL on any digital display (TV, camcorder, digital camera, or computers).

Each pixel has three micro-regions, each capable of emitting only one of the following colors: red, blue, and green. Your computer display produces images using these three color combinations. The display receives continuous codes for producing images. Each code triggers photons rays (in CRT) to hit these regions with just enough force to produce light and illuminate the pixel to the desired color. The process is continuous. For a display with "800 by 600" resolution, the rays move from first pixel on the first horizontal line to the last hitting the relevant pixels to create the image. In case of LCD, semi-liquid crystals create thermal power to illuminate the pixels while in case of plasma, there are ions hitting pixels to create the image.

Now that you understand how images are created on digital displays, we will talk about Windows screen savers. It is necessary to keep images moving on your display. This means it is necessary that the different pixels are hit each time. If you keep an image static for long, the same pixels are hit again and again for illumination to create and recreate the image because the pixels cool off within micro-seconds. Constant heating of the same pixels for a considerable period of time burns the interior of the screen where you can see the image (as a watermark) even as you are working on any application. Depending on how long the image was kept constant, the pixels may be damaged extensively rendering your digital display useless.

This is where Windows XP screen savers step in to protect your computer screen. You can configure any of the available Windows XP screen saver to start if the computer is idle for a certain period of time. You can also download different screen savers from the Internet. The ideal "wait time" before activating Windows XP screen saver is five to ten minutes. To select a screen saver and to configure the wait time, use the Display Properties dialog box (See Fig 2).

To summarize, the concept of Windows XP screen savers is to protect your display by keeping the images moving so that pixels are not overheated, which destroys the digital screen.