How a Projection TV Works

The Basics

A projection television uses an internal projector to cast a small image onto the much larger screen of the TV. There are three different types of projection TVs available today. The first is the CRT, or "cathode ray tube" television. In the case of a CRT projection TV, the internal projector shoots a beam of electrons at a screen that is coated in phosphor. The beam is then projected onto the TV's screen. A standard CRT TV could generally only be about 40 inches in size. Because of the nature of a projection TV, CRT projection TVs have the ability to be much larger.

LCD

An LCD (short for "liquid crystal display") projection TV uses a series of small computer chips to display an image on the screen. In this case, the internal projector uses tiny mirrors to transmit beams of light onto the computer chips. The strength of the beams of light manipulates the chips in such a way as to alter the brightness, contrast, and colors of the image being displayed. The light passing through the chips displays the image onto the TV screen.

DLP

A DLP (short for "digital light projection") TV takes a video source and projects it directly onto thousands of tiny mirrors. One pixel of the finished image represents each one of these mirrors. The overall resolution of the television represents the total number of mirrors. Once the video source has been successfully projected onto the mirrors, a computer chip then aids in projecting them directly onto the TV's screen.