Another day, another lawsuit. “PaidContent” (http://macte.ch/I0DtB) reports that Aspen, Colorado resident Jerald Bovino has filed a federal lawsuit against Apple, claiming the company’s Smart Cover for the iPad violates his 2005 patent for a portable computer case.

The US$39.95 iPad Smart Cover snaps onto the Apple tablet via a magnetic hinge. It protects the iPad screen and folds into a typing stand. Close it, and iPad automatically goes to sleep. Open it, and iPad instantly wakes up — no need to press any buttons.

Bovino’s claim is based on US patent 6,977,809 which describes an “integral case” that attaches to a computer. The patent says the invention is useful for situations like airport X-ray lines, notes “paidContent.”