DLP Projectors
Digital Light Processing (DLP) projectors were developed in 1987 by Texas Instruments.
DLP technology
The DLP projectors were a completely new concept that shook up the projector industry. The technology made use of micro mirrors. These mirrors were so small that it is perfectly justifiable to compare one mirror to one pixel. The light that fell on these mirrors passed through a rotating color wheel and this caused the mirrors to reflect a different light through the projector lens. While this created a kaleidoscopic effect on a micro scale, in actual practice the hundreds of individual mirrors would reflect a complex pattern of dots that the human eye would recognize as a complete picture. The arrangement of the micro mirrors in DLP projectors is known as the Digital Micro-mirror Device (DMD).
DMD
The DMD has two versions. The "single chip" version is simple where ordinary light passes through the colored wheel before reflecting off the DMD. This design also contains a transparent patch that permits white light to go through in order to increase picture clarity. The "three chip" projectors make use of a prism. Light first passes into the prism that breaks apart the light into the primary colors that are then reflected off the DMD before emerging from the projector lens. DLP projectors are able to project better images because of their construction. Single chip projectors can display 16.7 million colors while the three chip projectors can manage a staggering 35 trillion colors.
Home use
Owners of home theater systems especially love DLP projectors because of the high resolution and color density. While other types of projection systems are also used for reproducing the movie theater in a home, nothing compares to the power and clarity of DLP projectors. The clearest evidence that DLP projectors are the best option for home theater systems is that some movie theaters are using the same type of projectors. These theaters use optical discs, a technology quite similar to DVD, and the DLP projector uses these discs for input and the received images are projected on to the screen. In this way the DLP projector is far superior to DVD.
DLP and LCD
DLP projectors offer superior color accuracy when compared to LCD projectors. Other advantages include the lighter weight, lower power consumption, smaller dimensions, and better brightness and contrast ratios. The DMD in DLP projectors makes certain that LCD projectors will never be able to match that level of resolution and color clarity.
Disadvantages
Though everything looks rosy with DLP projectors there are a few disadvantages. There is a subtle "defect" in the very nature of the DLP and DMD technologies that will cause some people discomfort while watching it though most people will never even notice that anything is amiss. This is known as the "rainbow effect". While scanning the eyes across the screen (left to right or vice versa), some people tend to notice a rainbow like washout effect that trails their vision. As mentioned earlier, most people never notice this as it requires a special kind of visual acuity but the people who do notice it will be extremely annoyed.
Like LCD projectors, even the DLP projectors require a lamp replacement every 1000-2000 depending on usage and manufacturing quality. However, this disadvantage plays itself out because a lamp replacement would be required in any case no matter which projector is involved.
Perhaps that biggest disadvantage to DLP technology is that it is extremely expensive, at least for home use. DLP projectors can cost anywhere from $5000-$10000 in the mid-range. That is the cost of the projector alone, the other equipment for the home theater system will cost extra.