In one of yesterday’s posts, I mentioned a strategy for improving LCD display gamuts by changing the backlight.
…make the backlight three nearly-spectral colors, so that all the red filter has to do is block the blue and green primaries, all the blue filter has to do is block the red and green primaries, and all the green filter has to do is block the blue and red primaries
Here’s an announcement from a small Palo Alto company, Nanosys, and 3M that may be employing that strategy. It’s hard to tell because the press release is vague.
Here’s what Nanosys has to say about their technology:
Unlike conventional phosphor technologies such as YAG that emit with a fixed spectrum, quantum dots can actually convert light to nearly any color in the visible spectrum. Pumped with a blue source, such as the GaN LED, they can be made to emit at any wavelength beyond the pump source wavelength with very high efficiency (over 90% quantum yield) and with very narrow spectral distribution (only 30 – 40nm FWHM.) The real magic of quantum dots is in the ability to tune the color output of the dots, by carefully controlling the size of the crystals as they are synthesized so that their spectral peak output can be controlled within 2 nanometers to nearly any visible wavelength.
“FWHM” stands for “full width at half maximum”, and is the difference between the lower wavelength where the power is half of the power at the peak wavelength and the upper half-power wavelength. The clue that they’re about three discrete near spectral radiators in the backlight is the phrase “very narrow spectral distribution.”
Here’s a link that spells out what they’re doing.