Patent that took down Barnes and Noble's Nook revealed

Spring Design received patent 7,926,072 for multiple-screen technology covering APIs that enable single applications to communicate with complementary displays like LCD and E-Paper. Spring Design sued Barnes and Noble over the Nook e-reader's similar dual-screen design after debuting its Alex device one day before Barnes and Noble's 2009 Nook announcement. The companies settled last month, requiring Barnes and Noble to become a Spring Design licensee for the patented technology.