Rear Projection TVs
Whether CRT, DLP or LCD, there's a rear projector that fits
Rear projection is a method used by manufacturers to present a large display area by projecting the picture onto a screen, like a front projector seen at the theater. The difference is that the rear projector is projecting the images into a mirror and through a series of lenses that put the image onto a screen in front of the viewers. The entire projection is self-contained within the TV.
Conventional projectors are susceptible to light infiltrating the projection, washing out the picture before it hits the screen. Rear projectors are enclosed, so no light can affect the projection process. This is good for viewing when you have little control over ambient lighting such as a living room with large windows. Rear-projection TVs are larger TVs since the box is housing a whole projector, but modern display technologies make for astonishingly small TVs compared to the older CRT rear projectors, which were well-known for being the largest, bulkiest TVs available.
But the smaller footprint on your living room created by the newer display technologies comes at a cost. Larger CRT rear-projection TVs tend to be a lot cheaper because they're heavier and bigger. A 60" Mitsubishi CRT-based rear projector weighs in at almost 500 lbs. Compare that to some of the leaner LCD or DLP rear projectors with a 55"-60" viewing area that weigh less than 200 lbs. The depth of CRT rear projectors is much improved in recent years but still require the most space on the floor. A new Hitachi 50" rear projection TV is a foot thick - incredibly thin compared to the standard of just a few years ago. But some DLP rear-projection designs are just eight inches thick in the middle.
The digital display technologies that employ a rear projection method consist of DLP, LCD and its many variations including LCoS. The fixed-pixel displays project each pixel individually, usually from a reflection into lenses that focus the light into narrow beams onto a screen. The screen that catches the picture from the inside is very much like the screens used for CRT. These are called lenticular screens and specialize in presenting a wide viewing area. The technology behind these screens alone has increased as much as the display development itself. Sometimes when shopping for a TV the front projector can look so lean and slight, presenting a bright clear picture from every angle, that you might be hard pressed to tell the difference between a rear projector and a direct-view TV.Rear Projector Pluses
- The most affordable big-screen HDTVs available.
- A wide variety of display technologies from which to choose.
- The biggest TV sets are rear projection.
- Easier to integrate into your home system than a front projector.
- Limited brightness when viewing at an angle.
- Big TV means a big box in your living-room floor.
- Replacement bulbs can cost $300 for LCD, DLP and LCoS.
Rear projectors are best for viewing spaces that have lots of room for a big TV. The viewable area on a rear projector starts at about 42" and can go up to as much as 70". These are the most affordable of the big screen TVs and probably account for most of the TVs used in home theater systems throughout North America. Rear projectors shouldn't be considered if you have limited space for a TV or don't want a big screen. You should also look out for the peripheral viewing angles; rear-projector technologies have come a long way in recent years but still aren't perfect at presenting a bright image at angles.