Sony's no stranger to the odd e-ink device, but its latest prototype creation isn't targeted at the bookworm, it's intended to educate. The e-paper slate is quite a lot bigger than most tablets, let alone e-readers, sporting a 13.3-inch screen (1,200 x 1,600) to match the standard A4 size of normal, boring paper. That display is also an electromagnetic induction touchscreen for poking at menus and scrolling, but more importantly, it supports stylus input for scrawling notes and annotating PDFs (the only file format it currently supports). The prototype device is also only 6.8mm (0.27 inch) thick and weighs 358g (12.6 ounces) -- perfect for slipping into school bags. There's 4GB of on-board storage (with a microSD slot to increase that) and WiFi, which Sony plans to use for sharing notes with those who didn't make it to class on time. With WiFi off, the rechargeable battery inside is expected to last for three weeks of solid learning. These specs are for the prototype, of course, so after the late-2013 field trials at three Japanese universities, we might see some revisions before commercialization goes ahead sometime during the 2013 fiscal year.