MEMS Display Consumes Less Than 1 mW of Power

A new low-power MEMS-based display technology is making its mark in a variety of portable applications ranging from candy-bar-style mobile phones to smartphones to GPS-based golf range finders.

Known as a "mirasol(TM) display," the new technology is said to draw just a tiny fraction of the power of liquid crystal displays (LCDs) while offering greater viewability in sunlight. Since January, Qualcomm MEMS Technologies Inc. - maker of the mirasol(TM) display - has announced that Inventec Corp., Cal-Comp Electronics, LG Electronics Inc. and G-Core Co. Ltd. will use the display on their portable products.

"Anything that is portable, needs a display and runs on batteries is a candidate for this technology," says Jim Cathey, vice president of business development for Qualcomm MEMS Technologies.

The mirasol(TM) display technology, which hit the market about a year-and-a-half ago, is considered significant because it draws less than 1 mW of power, whereas conventional LCDs can use 200-250 mW. It works by using MEMS-based (microelectromechanical systems) Interferometric Modules (IMOD) that open and close, allowing light into an optical cavity whenever the appropriate voltage is applied by a driver chip. The key to the process is that the IMOD reflects ambient light into the display and, therefore, needs no backlight. As a result, its power requirements are far lower than those of conventional displays. Moreover, it's more usable in bright daylight.

"As ambient light increases, an LCD does not increase in brightness," Cathey says. "It can't get any brighter and the light washes out the display. Whereas with mirasol(TM), as ambient light increases, so does the light of the display."

Cathey says Qualcomm recently began marketing color mirasol(TM) displays, after initially launching monochrome versions. Portable product manufacturers are using both kinds of technology, he says.

Cathey adds that the Qualcomm has had "nine design wins" of late. In February, LG Electronics said it will begin incorporating color mirasol(TM) displays in its handsets. At the same time, Inventec announced its V112 Smartphone will feature a bichrome mirasol(TM) display as a "secondary screen," which will enable the unit to save power by redirecting content from the higher-power main display. Similarly, Cal-Comp Electronics has said it will use the new displays to reduce power consumption on its iT-810 mobile phones and G-Core announced it will employ the mirasol(TM) technology in its Mini Caddy GPS golf range finder.

"We've had design wins with monochrome," Cathey says. "Now we're starting to take the next step and move to color."

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