THE DLP SEMICONDUCTOR
At the heart of every DLP™ projection system is an optical semiconductor known as the Digital Micromirror Device, or DMD chip.
The DMD chip is probably the world's most sophisticated light switch. It contains a rectangular array of up to 1.3 million hinge-mounted microscopic mirrors; each of these micromirrors measures less than one-fifth the width of a human hair, and corresponds to one pixel in a projected image.
When a DMD chip is coordinated with a digital video or graphic signal, a light source, and a projection lens, its mirrors can reflect an all-digital image onto a screen or other surface. The DMD and the sophisticated electronics that surround it are what we call Digital Light Processing ™ technology.DIGITAL LIGHT PROCESSING I: THE GRAYSCALE IMAGE
A DMD panel's micromirrors are mounted on tiny hinges that enable them to tilt either toward the light source in a DLP™ projection system (ON) or away from it (OFF)-creating a light or dark pixel on the projection surface.
The bit-streamed image code entering the semiconductor directs each mirror to switch on and off up to several thousand times per second. When a mirror is switched on more frequently than off, it reflects a light gray pixel; a mirror that's switched off more frequently reflects a darker gray pixel.
In this way, the mirrors in a DLP™ projection system can reflect pixels in up to 1,024 shades of gray to convert the video or graphic signal entering the DMD into a highly detailed grayscale image.DIGITAL LIGHT PROCESSING II: ADDING COLOR
The white light generated by the lamp in a DLP™ projection system passes through a color wheel as it travels to the surface of the DMD panel. The color wheel filters the light into red, green, and blue, from which a single-chip DLP™ projection system can create at least 16.7 million colors. And the 3-DMD chip system found in DLP Cinema™ projection systems is capable of producing no fewer than 35 trillion colors.
The on and off states of each micromirror are coordinated with these three basic building blocks of color. For example, a mirror responsible for projecting a purple pixel will only reflect red and blue light to the projection surface; our eyes then blend these rapidly alternating flashes to see the intended hue in a projected image.