No Summary Judgment on Patent Marking Estoppel Doctrine

The court denied defendant's motion for summary judgment that plaintiff was estopped from asserting noninfringement under the patent marking estoppel doctrine. "[T]he Court is disinclined to estop [plaintiff] from claiming noninfringement based on a doctrine that enjoys questionable endorsement, if any, in the Federal Circuit and only sporadic application in the district courts. . . . Of equal concern is the apparent lack of any specific test or clear standard by which courts determine whether the doctrine applies beyond the general proviso that estoppel be imposed only when the defendant’s conduct is such that it would be 'inequitable' to allow it to assert noninfringement. . . . [E]ven if the doctrine remains viable, there is a triable issue of fact as to whether it applies under the circumstances presented here. . . . Conduct such as deliberate mismarking, attempts to benefit from both patent protection and noninfringement in an inconsistent manner, or conduct that creates a risk of consumer confusion or deception would potentially justify estoppel. The Court finds that the current record does not support such a conclusion in this case."

Ce Soir Lingerie Co. Inc. v. Imagine Enterprises LLC, 2-11-cv-07291 (CACD December 18, 2012, Order) (Gee, J.).