Somehow a lawsuit had to be lurking ... Barnes & Noble (NYSE: BKS), which took a spin on the floor with just about everyone before announcing its own e-reader, is being sued by Spring Design for misappropriation of trade secrets and violating a non-disclosure agreement. Cupertino-based Spring claims B&N “copied” features from its dual-screen Alex into the Nook. The Nook has a 6-inch grayscale screen for reading with a 3.5” color LCD below for touchscreen navigation; Alex includes Duet Navigator as a trademark.  Both are based on Android. (Update: We’ve posted the lawsuit.)

SEE ALSO: Marvell Syncs With E Ink On New E-Reader Tech Aimed At Mass Market

Spring Design says it started filing patents on Alex in 2006; the patent on Duet Navigator is pending. Starting on Feb. 12, 2009, spring 2009 (the lawsuit contradicts the press release), Spring says it worked with B&N under an NDA. We haven’t seen the lawsuit yet but the press release claims that through meetings, e-mails and calls, “Barnes & Noble’s marketing and technical executives extolled Alex’s “innovative” features, never mentioning their use of those features until the public disclosure of the Nook.”