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How DLP Sets Work


DLP Resolution and Reliability
Red, green and blue light emitting diode.
Red, green and blue light emitting diode.
Photo courtesy of PiccoloNamek

In the fast-paced world of improving technology, some manufacturers of the newer DLP TVs have replaced the color wheel, as well as the projection lamp, with light emitting diode (LED) technology to give a higher quality to the image on the screen. LED technology uses illuminated lights in red, green and blue to provide the color, as opposed to a color wheel. DLP is the only technology to use LED.

Some of the benefits include:

  • Wider color scale for more accurate and true-to-life colors. LED illumination increases the color saturation to nearly 140 percent of the standard and delivers a color refresh rate of up to 48 times the standard.
  • Higher level of brightness.
  • Contrast ratio up to 100,000 to 1. The simpler optical system reduces the unwanted effect of 'stray' light, allowing for better contrast ratios, which mean sharper, more detailed images.
  • Instant on and off functionality. There is better motion reproduction because pixel switching speeds in DLP technology are faster, allowing more accurate reproduction of fast-moving action without smearing.
  • Consistent picture. The on-screen image is always precisely converged, without the misalignment that can occur because there is only one screen panel, as opposed to three.
  • Longer-lasting light source (up to 60,000 hours).

There are also many other differences between DLP and other types of TVs, that make DLP a higher-quality product. In a traditional CRT TV, there are three "guns," or tubes, that can become misaligned. This causes the image to go out of alignment and appear fuzzy. You would need to have a trained technician come in and realign the tubes to restore a clear picture.

DLP is also insusceptible to phosphor burn-in, which can occur in plasma and CRT TVs. Phosphor burn-in is a permanent disfigurement of areas on the screen caused by still images being displayed continuously for long periods. For example, if you leave the TV on a channel that has a logo constantly showing, you may still be able to see the shadow of that logo when you change the channel.

Another advantage of DLP is the reduction of the "screen door" effect, also known as pixilation. Pixilation occurs when fine lines separate the projector's pixels and they are visible in the projected image. Because the space between each DMD mirror is microscopic, it is virtually impossible for pixilation to be visible.

Newer DLP sets can now be mounted on the wall.
Newer DLP sets can now be mounted on the wall.
Photo courtesy of OptomaUSA

The structure of a DLP also makes it one of the most reliable TVs on the market. What keeps a DMD from breaking or falling apart? There are three major components that keep it together:

  • The hinges that support the mirrors are made of a very thin, flexible film that is unlikely to break instead of a rigid substance
  • An anti-stick layer and spring-like contacts keep the mirrors from adhering to the landing surface
  • Hermetic seals keep particles of dust from getting into the DMD

DLP sets are much more affordable than the other plasma and LCD sets. They also come in larger screen sizes, yet remain slim and lightweight. Newer models are as small as 7 inches. In 2007, DLP wall-mounted sets were introduced to compete with the plasma and LCD screens, which provide increased contrast performance beyond 100,000 to 1.