Term of the Week - DMD (Digital Micro-Mirror Device)

The chip in a DLP video projector or DLP rear-projection television, that produces the image to be projected. The letters DMD stand for Digital Micromirror Device. Every pixel on a DMD chip is a reflective mirror. The video image is displayed on the DMD chip. The micromirrors on the chip (remember: each micromirror represents one pixel) then tilt very rapidly as the image changes. This process produces the grayscale foundation for the image.

In a single chip projection system, color is added as light passes through a high-speed color wheel and is reflected off of the micromirrors on the DLP chip as they rapidly tilt towards or away from the light source. The degree of tilt of each micromirror coupled with the rapidly spinning color wheel determines the color structure of the projected image. As the amplified light bounces off the micromirrors, it is sent through the lens and can be projected on a large screen.

In more advanced projection systems that use a 3-Chip design (one chip for Red, one chip for Green, and one Chip for Blue) the spinning color wheel is not required.