A CRT projector is a video projector that uses a small, high-brightness CRT (or picture tube) as the image generating element. The image is then focused and enlarged onto a screen using a lens kept in front of the CRT face. Most modern CRT projectors are color and have three separate CRTs (instead of a single, colour CRT), and their own lenses to achieve colour images. Each of its 3 primary color CRTs (Red, Blue and Green) generates a focused (but otherwise unimpeded) beam of electrons to draw its picture on a perfectly flat, smooth layer of colored phosphor, which is deposited on the inside of its optically clear glass faceplate. Modulating the beam current varies the brightness of each portion of the image - high current for white and no current for black, so the CRT projector emits no extraneous light.

The red, green and blue portions of the incoming video signal are processed and sent to the respective CRTs whose images are
focused by their lenses to achieve the overall picture on the screen. All CRT tubes come in a 4:3 format rather than a 16:9 configuration. Regardless of whether you project in a 4:3 format or a widescreen one, you want to use as much of the tube face as possible to maximize tube life. By using as much of the tube face as possible, you’ll also increase the maximum resolution out of the tube as you’re spreading the image out over a larger area of the tube face.

Projectors 3 tubes in the permanent roof. Unlike LCD projectors, CRT projectors are significantly more robust, more expensive and difficult to adjust. Compared to a Cathode-Ray Tube (CRT) projector, all other display systems create a paint-by-the-numbers type of picture. A CRT projector is the only type of video display that is virtually transparent to the image that it displays on your screen. CRT Video projectors are designed to be positioned a specific distance from the the screen and “square” to it’s surface. CRT projectors have many advantages over less expensive and more portable LCD (Liquid Crystal Display)and DLP (Digital Light Processing) projectors. Unlike these less expensive projectors, CRT projectors offer better resolution and higher quality images. Also, if you select a CRT projector you will not have to replace the light source as often as you would if you had purchased another projection technology.