Defendant was sufficiently prejudiced by plaintiff's ten year delay in filing suit to trigger laches. "If [plaintiff] had claimed that [defendant] infringed the . . . Patent in the 1990s, [defendant] would have stopped producing [the accused products] because it had not invested much money in the products at that time. . . . Although the court found that laches applied, the defendant did not meet the greater standard for equitable estoppel. "While [defendant] manufactured [the accused products] for over ten years, [plaintiff] stood by silently, never threatening to bring suit for infringement of [its] patent or even demanding that [defendant] purchase a license for the patent. . . . Equitable estoppel requires more. It requires that the plaintiff take some misleading action beyond mere silence."
Integrated Cards, L.L.C. v. McKillip Industries, Inc., 1-06-cv-02071
(ILND November 19, 2009, Memorandum Opinion & Order) (Kendall, J.)