An LCD projector is a type of video projector for displaying video, images or computer data on a screen or other flat surface. It is a modern equivalent of the slide projector or overhead projector. To display images, LCD projectors typically send light from a metal-halide lamp through a prism or series of dichroic filters that separates light to three polysilicon panels – one each for the red, green and blue components of the video signal. As polarized light passes through the panels, individual pixels can be opened to allow light to pass or closed to block the light. The combination of open and closed pixels can produce a wide range of colors and shades in the projected image.
Liesegang LCD Projector
Gene Dolgoff's original LCD Projector prototype.
Typical 3LCDs (RGB) projector showing separated polarizers
A video projector is an image projector that receives a video signal and projects the corresponding image onto a projection screen using a lens system. Video projectors use a very bright ultra-high-performance lamp, Xenon arc lamp, metal halide lamp, LED or solid state blue, RB, RGB or remote fiber-optic RGB lasers to provide the illumination required to project the image. Most modern projectors can correct any curves, blurriness and other inconsistencies through manual settings.
A projector in a standard form factor: The PG-D2870 projector from Sharp, which uses Digital Light Processing technology
An image from a video projector in a home cinema
A Zenith Electronics 1200 CRT-projector-based home theater, ca. 2006