Apple is being sued by a man in Colorado over claims that the company’s $39 iPad Smart Covers violate a “Portable Computer Case” patent originally filed in 2003 and issued in 2005. PaidContent obtained a copy of the lawsuit.

The United States patent in question is 6,977,809. A Colorado man owns it, Jerald Bovino, who is seeking royalties for sales of Smart Covers’ using his invention. An excerpt from the patent seems to describe functionality that is quite similar to Apple’s Smart Covers—at least the ribbed design:

an openable case defining an exterior surface for holding the computer; and a plurality of resilient ribs positioned on said exterior surface of said case wherein said resilient ribs protects said computer from wear and tear during the transporting and use of the computer.

Perhaps coincidental timing, Apple was granted a design patent for its iPad Smart Covers this week (as reported by PatentlyApple).