LCD Projectors

An LCD projector is a device utilized for displaying video images or data. They are the modern equivalent to the slide projector and overhead projector used in the past. more...

LCD (liquid crystal display) projectors usually contain three separate LCD glass panels, one each for the red, green, and blue components of the video signal. As light passes through the LCD panels, 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.

With a lens that "projects" the image on any flat surface and does not require large "furniture" (like a big TV would), LCD projectors tend to be smaller and much more portable than older systems. The best image quality can be accomplished with a blank white or grey surface to project on, and for this reason dedicated projection screens are often used.

Early systems were often intended to be used with existing overhead projectors, built as a large "plate" that was put on the projector in place of the transparencies. This provided the market with a stop-gap solution in the era when the computer was not yet the universal display medium.

This technology is employed in some sizes of rear projection television consoles, as there are cost advantages when employed in mid size sets (40 to 50 inch diagonal). This is not expected to have much longevity in the "home theater" marketplace due to expected improvements cost/performance of competing technologies, particularly in direct-view LCD panels at the lower range of sizes and DLP projection in the larger sizes.

In 2004 and 2005, LCD front projection has been enjoying a come-back because of the addition of the dynamic iris which has improved contrast up to the levels of DLP.

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