Re: Quantum Dot Technology [backlight technology]
Posted: 25 Sep 2014, 19:11
I watched that video posted on the previous page and found it quite informative. Two things I didn't see addressed: the lifetime of a QD backlight, in particular uneven deterioration rates affecting white point, and the possibility of deep blue/UV light coming through to viewer's eyes. I especially wonder about the latter in a display which uses QD directly on the subpixels rather than in the backlight layer.
Otherwise, I learned a lot. My takeaway is that as a backlight layer, they essentially replace the white phosphor in a WLED, and move it from each LED to a layer behind the LC layer (this decouples it from the LEDs, giving more choice in what blue LEDs to use). And further, rather than trying to emit a broad spectrum ("spectra" as the guy kept erroneously saying heh), you only emit peaks at the three primaries, so that little light is wasted being blocked by the color filters in the LCD. This also means that the color filters don't determine spectral purity, as they only have to filter out the other two primaries, not the colors inbetween (it sounds very much like using oversampling, where you don't need such a good analog Nyquist filter, instead moving them way above the passband so a simple filter is sufficient). And as mentioned in the video, this means more efficiency and color purity than even an RGB LED backlight.