What Is 'Patent Misuse'?

"Patent misuse" is perhaps one of the most "misused" phrases in patent law. When faced with a patent lawsuit or even just a cease-and-desist letter, accused infringers who disagree with the patent holder's actions often ask whether they can counter the infringement accusation with a claim of patent misuse.

Which leads to the question: what exactly is "patent misuse" in U.S. patent law?

Patent misuse can occur when a patent holder improperly tries to expand the scope of the patent in a way that has an anti-competitive effect. (See B. Braun Med., Inc. v. Abbott Labs, 124 F.3d 1419, 1426 (Fed. Cir. 1997).) Patent misuse requires more than just aggressive litigation tactics or disagreement as to whether or not an accused product actually infringes: "the defense of patent misuse is not available to a presumptive infringer simply because a patentee engages in some...