The folks at iFixit recently tore apart the Barnes & Noble Nook Simple Touch with GlowLight and, as they are wont to do, have offered up a detailed run-down analyzing the device's innards. Obviously the biggest feature that separates B&N's latest e-reader from previous models is its GlowLight technology that allows owners to read in the dark, so the teardown naturally places the most emphasis there.
We already knew LEDs above the display act as the light source, but the process of distributing that light across the Nook's screen is actually quite sophisticated. The glass that sits atop the e-ink panel has been engineered with a diffraction grating, meaning it contains tiny slits or grooves that help cast light over the entire reading area. "Barnes & Noble really did their homework on this one," says iFixit. "Because instead of a simple linear diffraction grating (think of a bunch of parallel slits), it appears that the diffraction grating varies throughout the glass to evenly disperse the light." That sounds like pretty serious science when you step back and remember we're talking about a $139 e-reader.
Other than that, differences between B&N's Nook Simple Touch with GlowLight and the company's previous hardware are fairly minimal. The latest model contains a magnesium internal frame, for instance, whereas the one found inside the non-lit $99 Nook is made from aluminum. If you're thinking of conducting your own teardown, iFixit has awarded the device a repairability score of 7/10, with copious amounts of adhesive and a fused display assembly as the main points of worry. But we get the sense that what you're really after are pictures of the dissembled gadget, and those await you at the source.