| ahzhuo |
2007-11-27 10:34 |
High-Definition TV from your Cell Phone (fw)
A cell phone that can project a high-definition television image could soon be possible, say researchers at Cornell University who have developed a new microelectromechanical system (MEMS) for rapidly scanning wide areas with a laser. A projector based on the device would be about the size of dime and could cast a meter-wide image on a surface only half a meter away. ~h)@e\Kc
The key is a small mirror, about half a millimeter across, suspended by carbon fibers -- rolled-up sheets of crystalline carbon commonly used to reinforce materials. The fibers amplify the vibrations of a piezoelectric motor, moving the mirror. This movement deflects a laser at different angles, causing it to sweep back and forth across a surface. While the current device only moves the laser side to side, the researchers say it can be easily mounted on a stage that tilts up and down to allow the device to sequentially draw each line of an image, using complex electronics that turn the laser on and off as it is directed across the screen to create the light and dark pixels. A full-color display would mix light from red, green, and blue lasers. 5: daa
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MEMS-based displays already exist in commercial products. Texas Instruments, based in Dallas, TX, for example, has developed a chip that uses millions of tiny mirrors, each of which turns pixels on and off by either turning toward or away from a light source (see "May the Micro Force Be with You"). This chip is now used in a variety of televisions and movie projectors. Another company, Microvision, in Redmond, WA, uses a single mirror MEMS device more like the one being developed at Cornell, but without the carbon fibers. The company is developing a full-color display. ~u
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