It took a long time for traditional slide projectors and transparency projectors to die away, mostly because it took a long time for product engineers to figure out how to project a computer image onto a large screen. Digital LCD projectors are finally on the market, however, and are getting more affordable each year.

Varieties of LCD Projectors

If you're unfamiliar with the term LCD, it actually stands for "liquid crystal display," and it is the same technology that was used in the first digital watches. LCD quality has obviously improved over the years, incorporating millions of colors and much higher resolutions. Inside each digital LCD projector, however, is a tiny LCD screen not much bigger than those on the first digital watches.

LCD projectors work by transferring the image on the tiny LCD screen (produced from your computer's display output, much like a normal monitor) into a beam of light that expands and lands on a large projection screen. Standard LCD projectors use a single LCD chip that tends to get very hot after hours of operation. This means that the picture quality will eventually deteriorate if the projector is left on.

A newer and more advanced type of LCD project is the polysilicon LCD projector. Polysilicon projectors use three separate LCDs (one for each primary color) and they can generate a much better color saturation than traditional LCD projectors. They are also less prone to picture degeneration.