The best potential advantage of quantum dot LEDs (QD-LEDs) is that they use much less power than LCDs. In LCDs, a backlight illuminates every pixel on the screen. Dark pixels are simply blocking this light, in effect wasting energy. In part because quantum dots emit light rather than filtering it, a QD-LED display could potentially use one-30th the power of an LCD. Coe-Sullivan of QD Vision, says he expects that it will be about four years before the company has its first commercial product — probably a small display for a cell phone. But he says the colorful images will be worth the wait.