DLP Projector Technology
Digital Light Processing (DLP) is a trademark owned by Texas Instruments, representing an intelligent display technology that is used in a variety of display applications from traditional static display to interactive display and also non-traditional embedded applications including medical, security, and industrial uses. It was originally developed in 1987 by Dr. Larry Hornbeck of Texas Instruments.
DLP technology can be found in DLP front projectors (standalone projection units for classrooms and business primarily) as well as DLP rear projection television sets and digital signage.
Single-chip DLP projectors
In a projector with a single DLP chip, colors are produced either by placing a color wheel between a white lamp and the DLP chip or by using individual light sources to produce the primary colors. The color wheel is divided into multiple sectors: the primary colors: red, green, and blue, and in many cases secondary colors including cyan, magenta, yellow and white. The use of the secondary colors is part of the newer color performance system called BrilliantColor which processes the primary colors along with the secondary colors to create a broader spectrum of possible color combinations on the screen.
Three-chip DLP projectors
A three-chip DLP projector uses a prism to split light from the lamp, and each primary color of light is then routed to its own DLP chip, then recombined and routed out through the lens. Three chip systems are found in higher-end home theater projectors, large venue projectors and DLP Cinema projection systems found in digital movie theaters.
According to DLP.com, the three-chip projectors used in movie theaters can produce 35 trillion colors. The human eye is suggested to be able to detect around 16 million colors, which is theoretically possible with the single chip solution.
DLP Technology Advantages
- Smooth (at 1080p resolution), jitter-free images
- Perfect geometry and excellent grayscale linearity achievable
- Usually great ANSI contrast
- No possibility of screen burn-in
- Less "screen-door effect" than with LCD projectors
- DLP projection display is typically much less expensive than LCD or plasma flat-panel displays and can still offer 1080p resolution.
- New LED and laser DLP display systems eliminate the need for lamp replacement.
- DLP projectors do not suffer from "color decay", often seen with LCD projectors in which the image on the screen yellows after extended periods of usage.
DLP Technology Disadvantages
- Some viewers are bothered by the "rainbow effect" - particularly in older models.
- Replacement of the lamp / light bulb in lamp based units. The average life span of a mercury lamp averages 2000–5000 hours and the replacement cost for these range from $99 – 350, depending on the brand and model.
- Some viewers find the high pitch whine of the color wheel to be an annoyance though the drive system can be engineered to be silent and some projectors don't produce any audible color wheel noise.
- Dithering noise may be noticeable, especially in dark image areas. Newer (post ~2004) chip generations have less noise than older ones.
- Error-diffusion artifacts caused by averaging a shade over different pixels, since one pixel cannot render the shade exactly
- May use more electricity, and generate more heat, than competing technologies.
- Some people may be able to observe a phenomenon in which the projected contents appear to be cycling through it colours for the duration of the presentation. This is most easily seen by using a camera's 'live view' mode on projected content.