"Equitable estoppel" as a defense to false marking? Nah

Advanced Cartridge Technologies has sued Lexmark here in Tampa for infringement of a handful of patents and false marking. Regarding the false marking allegations, ACT claims that Lexmark lists a bunch of patents on various products, and there are various issues with those patents. ACT also argues that each product is not covered by each patent, and thus it is false marking to include all of them on the packaging. Lexmark responds that it is not subject to false marking liability in part because it includes a disclaimer stating that the product is covered by one or more of the listed patents. Thus, because each product is covered by at least one of the listed patents, Lexmark argues it should not be subject to false marking liability because of its disclaimer. ACT disagrees that the disclaimer shields Lexmark.

In discovery, Lexmark learned that ACT marked a waste bin product with some toner patents. Lexmark asked for leave to file an amended answer so that it could assert the affirmative defenses of unclean hands and equitable estoppel "in light of [plaintiff's] interpretation of the false marking statute."

The Court took a paragraph to deny Lexmark's motion:

The plaintiff asserts a false patent marking claim. Alleging that the plaintiff also engages in false patent marking, the defendant moves (Doc. 105) for leave to file an amended answer asserting “the affirmative defenses of unclean hands and judicial estoppel.” However, the proposed defenses, perhaps legally and factually dubious in this instance, are untimely raised and probably productive of unwarranted delay and unnecessary expense.* The defendant's motion (Doc. 105) to file an amended answer is DENIED.

* The defense of "equitable estoppel" appears meritless in the present circumstances. The defense of "unclean hands," if available, requires a distinct showing of inequitable and pertinent conduct. Interestingly, the defendant identifies no case in which the equitable defense of "unclean hands" has barred a statutory false patent marketing claim.

Advanced Cartridge Technologies, LLC v. Lexmark International, Inc., slip op. Case No. 8:10-cv-0486 (M.D. Fla. Apr. 14, 2011) (J. Merryday)