LCD or liquid crystal display projectors usually contain three separate LCD glass panels, one each for red, green, and blue components of the image signal being fed into the projector. Light passes through these LCD panels, and individual pixels can be opened to allow light to pass or closed to block the light, as if each little pixel were fitted with a Venetian blind. This activity modulates the light and produces the image that is projected onto the screen.
DLP ("Digital Light Processing") is a proprietary technology, it works quite differently than LCD. Instead of having glass panels through which light is passed, the DLP chip is a reflective surface made up of thousands of tiny mirrors. Each mirror represents a single pixel. In a DLP projector, light from the projector's lamp is directed onto the surface of the DLP chip. The mirrors move back and forth, directing light either into the lens path to turn the pixel on, or away from the lens path to turn it off.
