DLP (Digital Light Processing)

Digital Light Processing (DLP) is a technology patented by Texas Instruments, a technology used in projectors. This technology is used in front projection and rear projection televisions. It is also one of the leading technologies used in digital cinema projection.

Digital Micro-mirror Device
In DLP projectors, there is an array of small mirrors (microscopic) that are positioned on a semiconductor chip called Digital Micro-mirror Device (DMD). Each mirror produces one or more pixels in the image. The number of mirrors is the maximum resolution attainable by the display, e.g. 800×600, 1,204×768, 1,280×720, and 1,920×1,080. The mirrors can either pass the light through the lens (On) or completely block the light (Off) and they can switch positions quite rapidly. Controlling the on and off times can produce different shades of grey.

How colour is produced in DLP projectors?
There are three methods available to DLP projectors for colour production:

• Single-chip DLP projectors
• Three-chip DLP projectors
• Sequential illumination by three LEDs (light emitting diodes) (still in development, only in select Samsung models)
  

Single-Chip Projectors
In single-chip projectors, colours are either produced by a colour wheel between the lamp and the DLP chip or by using individual light sources to produce primary colours (e.g. LEDs).

Three-Chip Projectors

In three-chip projectors, a prism is used to split light from the lamp and each primary colour is projected to its own chip, then recombined and routed out through the lens. These are used in higher end projectors. They are capable of producing 35 trillion colours. It is suggested that the human eye can detect around 16 million colours


Digital Cinema
DLP is the current market-share leader in professional digital movie projection, largely because of its high contrast ratio and available resolution as compared to other digital front-projection technologies. As of December 2008, there are over 6,000 DLP-based Digital Cinema Systems installed worldwide.

Pros

• High resolution images (up to 1,080p)
• Perfect geometry and excellent greyscale linearity achievable
• High contrast
• No possibility of burn-in
• DLP rear projection televisions are considerably cheaper than LCD or plasma flat-panel displays and can still offer 1,080p resolution
• DLP Projectors can process up to 7 separate colours giving them strong colour performance
• DLP projectors do not suffer from “Colour Decay” often seen with LCD projectors in which the image on the screen turns yellow after extended periods of usage
  

Cons

• Not as thin as LCD or plasma flat-panel displays
• Dithering noise may be noticeable, especially in dark image areas. Newer (after 2004) chip generations have less noise than older ones
• Lower viewing angle than direct-view technologies such as CRT, plasma, and LCD