Qualcomm's mirasol display technology brings color and video to eReaders
By Alan Brandon
January 10, 2010
As eReaders such as the Kindle and the Nook establish themselves with consumers, manufacturers are already looking ahead to the next generation of devices. Moving beyond e-ink, tomorrow’s eReaders will feature color displays and the ability to show video as well. To meet the needs of the most demanding users, eReaders will also need to feature long battery life and displays that are bright enough to read even in direct sunlight. Qualcomm’s Mirasol displays, which will begin shipping this year, address these needs using technology that mimics the coloration of a butterfly’s wings.
Mirasol displays are interferometric modulator displays (IMODs), a type of microelectromechanical system (MEMS) that use a tiny moving reflective surface to change color states. Each pixel in an IMOD is individually addressed, similar to the way an LCD works. The pixels in a Mirasol IMOD display mimic the tiny scales on a butterfly’s wings that make it appear to shimmer. In each IMOD picel a miniscule interferometric cavity, made up of a reflective membrane and a thin-film stack, either reflects light or not depending on the state of the membrane. The air gap between the membrane and the film determines the color of the pixel.
IMOD pixels require little power except when their state is being changed. This makes IMODs more energy efficient than LCD-type displays. Because IMODs are reflective displays, they actually become brighter when there is more ambient light. This makes them easier to see in direct sunlight or other bright conditions. E-ink technology is similarly reflective, which is why a Kindle screen can easily be read in sunlight, but not a laptop display. Another plus for the Mirasol technology is that it has a faster refresh rate than e-ink. Not only do static images appear more quickly, says Qulacomm, but Mirasol displays can also show video.
At CES 2010, Qualcomm was demonstrating a 5.7in (14.5cm) Mirasol display running at 1024 by 728 pixels. A 10in (25.4cm) version is in the works. Qualcomm says they won’t be manufacturing eReaders themselves, but are working to supply OEM partners who want an alternative to e-ink and LCDs. Look for the Mirasol-equipped products to begin shipping in late 2010.
For additional information visit mirasoldisplays.com.