How DLP works

To meet these power requirements, designers need to understand the basic working principles of DLP chips and some of the options for providing power in the application.

How DLP Works
A DLP chip is a complex light switch that contains a rectangular array of up to 2 million hinged micromirrors, each measuring 16 microns by 16 microns. When the DLP chip works in conjunction with a digital video or graphic signal, a light source, and a projection lens, its mirrors reflect a pure digital image onto a screen or other surface. Each micromirror in a DLP
chip is mounted on a tiny hinge that allows it to tilt toward the light source when it is in a DLP projection system (on) or away from the projection system (off), making pixels on the projection surface brighter or darker. The image encoding of the bitstream input to the semiconductor instructs each micromirror to switch on and off at a rate of up to thousands of times per second. When a micromirror is turned on more often than it is turned off, it reflects a light gray pixel; when it is turned off more often, it reflects a dark gray pixel. In this way, the micromirrors in a DLP projection system can reflect pixels with up to 1024 shades of gray to convert the video or graphic signal input to the DLP chip into a very complex grayscale image.
The white light produced by the bulb in a DLP projection system passes through a red, green, and blue color image filter as it travels to the surface of the DLP chip. After passing through the filter, the colored light then falls on the DLP chip in sequence to form an image with up to 16.7 million colors. Some DLP projection systems incorporate a three-chip architecture that can project up to 35 trillion colors.
The on and off states of each micromirror are coordinated with these three basic building blocks. For example, the micromirror responsible for projecting a purple pixel will only reflect red and blue light onto the projection surface. Our eyes then mix these rapidly alternating colors to see the expected hue in the projected image (see Figure 1).