Front-projection televisions: A front-projection television uses a projector and a separate screen to project images onto the front of that screen. This setup is very similar to what you would find in a movie theatre.
Rear-projection televisions: Rear-projection systems look more like traditional televisions. They display images on the back of a screen rather than the front, and the projector is completely contained within the television itself.
This type is specific to large-screen displays. Up until mid-2000s, most of the affordable large screen televisions (up to 100 inches) used this technology. They first appeared in 1970’s but they were outwitted by CRTs. The projection televisions are thicker than LCD and plasma displays; however, newer models are smaller than their predecessors. Earlier models were basically CRT and their picture was fuzzy at close range. Newer models incorporate DLP, LCD, and LCoS (Liquid Crystal on Silicon). LCoS is able to generate 1080p resolution (1080 horizontal lines progressive). In 2005 and 2006, these televisions were much cheaper than LCD and plasma panels. But as the prices on these competitors fell, sales of projection televisions declined dramatically. These televisions are able to display a variety of resolutions, and their blackness and contrast levels are excellent. They also offer better viewing angle than LCDs and have long lives. Older models had limited viewing angle with the optimum viewing position being one directly in front of and eye-level with the unit.
The main drawback for these televisions is their large footprint and glare if a light source is placed at complementary angle to your viewing angle; the problem gets worsened if the television is protected with a screen saver (a clear protective material that covers the fragile screen). Furthermore, price of changing the lamp (every 3-5 years) is substantial compared to the television price itself.
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