TITLE: "Digital Light ProcessingÔ"

SPEAKER: Dr. Randall Ledford ,

TIME: Thursday, March 18, 1999, starting at 4:00 PM

PLACE: George P. Williams, Jr. Lecture Hall, (Olin 101)

Digital Light Processing (DLPÔ) is an emerging technology based on spatial light modulation using a new semiconductor device developed by Texas Instruments. This device, the DMDÔ (digital micromirror device), is classified as an advanced micro-electromechanical system (MEMS). DLP is the use of one or several DMD's in conjunction with high speed DSP (digital signal processor) processing and optics to process digital information into various images or to perform optical switching tasks. Current applications are focused on digital projection systems which surpass both conventional LCD and CRT techniques. Optical efficiencies of approximately 90% are achievable versus 30% with LCD's. Greater color saturation, 7000 degrees K SMPTE C color balance and greater than 2000 ANSI lumens are possible. Later planned applications include optical switching systems and electro-photography enhancements. DMD's are produced in arrays of 16 micron square pixels. Projection area arrays range from 480x640 VGA arrays to 2048x1156 arrays for HDTV. The latter large array possesses 2.3 million moving parts and 6 million transistors and is generally considered the world's most sophisticated MEMS. A electro-photography DMD is a linear array of 7056x32 pixels and at 5.5 inches is the world's longest semiconductor. A number of advanced semiconductor processes will be reviewed which were required to produce these DMD devices. Several technology breakthroughs were required to produce DMD's and will be discussed. In addition to semiconductor physics, advances were required in metallurgy, low friction chemical polymers, specialized DSP's and optics. These will be reviewed in the context of a necessary technology convergences to enable DMD functionality. The semiconductor design will be discussed in terms of an evolution of different geometric configurations which have led to the current design. A summary of the technical obstacles overcome will be reviewed.