Rear Projection TV's: What to Know

As it sounds, a project television, or more commonly a "rear-projection" TV works by projecting an image from behind the screen itself. Currently, there are three main types of technology used in rear-projection TV's: CRT, LCD, and DLP. Each uses a combination of projection devices, magnification lenses, mirrors, and screens to produce the image seen. However, each takes an alternate approach and each has its own sets of advantages and disadvantages.

CRT

CRT, or Cathode Ray Tube, technology is the most basic and has been around the longest of rear-projection technology. It involves using three CRTs, one for each of the primary colors, to project the image onto the screen. The advantages of this basic technology is that it is the cheapest to manufacture and that it can produce arguably the widest array of colors. Additionally, CRTs can be configured for a broad range of resolutions.

Drawbacks to CRT technology also stem from the fact that it is the oldest and most basic of the rear-projection technology. The projectors are usually large and take up a lot of space and the design of the projection system makes it so that everything needs to be aligned perfectly for the best possible quality. CRTs are also the most prone to "burn-in's," basically images being "burnt" onto the screen due to them being displayed for extensive times without moving.

LCD

LCD, or Liquid Crystal Display, uses very different technology than that of the CRT projection TV. LCD projection TV's utilize a powerful light which is passed through an LCD chip containing the video pixels themselves which are in turned magnified through a lens and then projected onto the screen itself. As it sounds, the strengths of such technology are that it is very compact and portable and uses less power to run. It also has good contrast and brightness capabilities.