In Aspex Eyewear Inc. v. Clariti Eyewear, Inc., No. 2009-1147 (Fed. Cir. 5/24/2010), Aspex sent Clariti several letters in 2003 alleging infringement of Aspex patents pertaining to eyewear. The last letter from Clariti was sent in June, 2003. Aspex then had no further contact with Clariti until August, 2006, when Aspex again renewed its allegations that Clariti was infringing. Aspex then filed its infringement suit in March, 2007.
Clariti’s defense was that the patents were invalid, and Clariti also moved for dismissal on the grounds of equitable estoppel. The District Court (SDNY, Chin) agreed that equitable estoppel applied and awarded summary judgement in favor of Clariti.
On appeal to the Federal Circuit, (Newman, Rader, Bryson, opinion by Newman, dissent by Rader), the opinion set forth the elements of equitable estoppel:
In the context of patent infringement, the three elements of equitable estoppel that must be established are: (1) the patentee, through misleading conduct, led the alleged infringer to reasonably believe that the patentee did not intend to enforce its patent against the infringer; (2) the alleged infringer relied on that conduct; and (3) due to its reliance, the alleged infringer would be materially prejudiced if the patentee were permitted to proceed with its charge of infringement. Aspex at 6.
Aspex countered that the 2003 letters named no specific alleged infringing products, but the 2006 letters did name a specific product. Aspex also argued that the sales volume of the alleged infringing products was small in 2003 and did not justify a suit. But Clariti argued that it developed its business in the alleged infringing products in part because Aspex seemed to have lost interest in enforcing its patents. Newman concludes (slip op. at 13) that the elements of equitable estoppel were established, so the suit is dismissed.
Rader’s dissent asserts that the court improperly expanded the doctrine of equitable estoppel. Rader would have held that the 2003 letters were not specific enough in listing allegedly infringing products and claims at issue, and did not create a reasonable apprehension of suit. Rader also asserts that Clariti failed to show that it relied on Aspex’s silence in developing the business of the alleged infringing products. Rader concluded that this case “expands the equitable estoppel doctrine beyond this court’s precedent with respect to both misleading conduct and material prejudice,” and was not ripe for summary judgement.