Video Projectors: Choosing the Right Technology
A number of video projector technologies are
available today for use in a home theater—including Liquid Crystal Display (LCD), Digital Light Processing (DLP), and Liquid Crystal on Silicon (LCOS, sometimes called D-ILA).
LCD projectors share many of the advantages and limitations of LCD Panel displays. Inexpensive, low performance, high light output models are widely available. Some higher end “three chip” models achieve high image quality, coupled with high light output. Because of their brightness, LCD projectors are widely used in commercial applications. Very inexpensive models designed for power point presentations in small rooms are sometimes marketed as “home theater” projectors, but produce marginal picture quality.
DLP Projectors use a micro-array of movable mirrors to create an image. They generally have lower light output than LCD models, but typically display better contrast and richer (and more accurate) colors. Less expensive models use a single DLP chip to produce the standard red-green-and blue picture elements sequentially, together with a synchronized color wheel to provide the actual colors. Be aware that some people see color fringing with single-chip DLPs. This is experienced as rainbows in their peripheral vision.
More expensive DLPs models use three chips—one each for red, green, and blue colors—then uses a prism to combine the components into a single light beam. These projectors can produce a much brighter image than the single-chip models, without the possibility of color fringing. Most of the high-performance home theater projectors currently available are three-chip DLP models.
D-ILA (or LCOS) Projectors, a reflective micro-array technology like DLP, uses liquid crystals instead of mirrors to form the pixel display. D-ILA technology provides a rich, cinematic image, with high usable contrast, and high resolution, with reduced spacing between the pixel elements that make up a digital display. Light output (brightness) is typically low—more like a movie theater image—requiring that the room be darkened for best results.
LED Lamps. LED lamps use much less energy and last much longer than incandescent bulbs. So manufacturers have begun to redesign their projector lines, using LED light sources instead of incandescent lamps. Unfortunately, this is not a consumer retrofit project: the projector must be designed for LED technology. Whether projector manufacturers will rename their projectors “LED” when they switch over is yet to be seen. If so, it will add to the confusion. See An Insider’s Guide to Home Theater