Plaintiff's patent was not unenforceable due to prosecution laches. Although "[plaintiff] waited more than six years after filing the parent patent application before telling the PTO it had claims to 'automatically complet[ing] an on-line purchase' . . . [d]uration of prosecution . . . does not provide a bright-line rule as to the reasonableness of prosecution. . . . The court must look to the prosecution history of the patent family as a whole. During the period [defendant] contends constitutes undue delay, however, [plaintiff] was prosecuting other applications in the patent family. [Plaintiff] also explains that '[a]s with most small technology companies with limited resources, [plaintiff] had to be selective in filing patent applications, and [plaintiff's] five applications were filed in 1996, 1996, 1998, 2000, and 2002, respectively' . . . That explanation is reasonable . . . Moreover, the court notes that [plaintiff's] patents were all filed after June 1995, and, therefore, was not extending its patents’ term by delaying to file the claims of the [patent-in-suit]."
Cordance Corp. v. Amazon.com Inc., 1-06-cv-00491
(DED June 30, 2009, Memorandum and Order) (Thynge, J.)