Sometimes trying to figure out data projector technology is like dealing with the government, with all the TLAs (three-letter acronyms). LED, LCD, DLP…what do they all mean?
First of all, there’s two basic components in a projector: lighting, and the imaging/display device technology, says Joe Gillio, director of product marketing for Casio America Inc., in Dover, N.J.
Traditionally, there’s been one type of lighting source — the lamp — though the technology behind the lamp has improved over time. The move to metal halide bulbs, and then to the ultra-high pressure mercury lamps used today, has both reduced the cost of the bulbs, and improved their lifetimes. The result is that projectors using bulb technology are more reliable today than they ever have been before, says Felix Pimentel, product manager for Optoma Technology Inc., in Fremont, Calif.
But in the past few years, the industry has developed projectors using a different lighting source, the light-emitting diode (LED). LED-based projectors offer a number of advantages over traditional lamp-based systems.
First, they tend to have a longer lifespan — up to 20,000 hours, compared with the mercury vapor lamp, says Gillio. This makes the projectors more reliable, because they fail less often, and don’t “burn out” like lamps do. In addition, the mercury in LCD projectors is environmentally hazardous, he says, which is not a factor with LEDs.
While the LED light sources are more expensive, they save money in the long run because they fail less often, Gillio says. Because lamps aren’t typically the kind you can go down to the corner and buy, a salesman on the road or a teacher in the classroom with a blown bulb faces the cost of the downtime until the bulb can be replaced, he says.
Another advantage of the LED lighting systems is that they provide a larger number of colors, and more saturated colors, on the screen, meaning the LED system “looks” brighter, Pimentel says. LED projectors also tend to have fewer parts because the LED performs some of the functions that require additional parts in lamp-based projectors. This means LED-based projectors can be smaller and lighter than lamp-based ones, he says. They also use as little