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Microelectromechanical Systems
MEMS have a movable or deformable reflective surface on top of a semiconductor chip. The chip generates voltages in response to digital information. The voltages change the shape of the reflective surface rapidly and in a controlled way to produce the image that was encoded by the digital information. The projected light bounces off the reflective surface and gets collected by the projector lens.Digital Micromirror Devices (DMD)
 Photo courtesy Texas Instruments SXGA DMD (1280 x 1024 pixels, 1,310,720 mirrors) |
DMDs, also called digital light processing (DLP), were developed by Texas Instruments. The DMD is a chip that has anywhere from 800 to more than 1 million tiny mirrors on it, depending upon the size of the array.
 Photo courtesy Texas Instruments Micrographic photo of ant leg on the DMD surface: Each mirror is 16 µm2, with 1 µm separation between pixels. |
Each mirror rests on support hinges and electrodes.
 Photo courtesy Texas Instruments The top left view shows nine mirrors. In the top right, one central mirror was removed to expose the underlying hidden-hinge structure. The bottom right shows a close-up view of the mirror substructure. The mirror post, which connects to the mirror, sits directly on the center of this underlying surface. The bottom left shows several pixels with the mirror removed. |