In a decision unsealed on May 3, 2013, Judge Leonard P. Stark rejected both parties’ inequitable conduct defenses, finding that neither proved by clear and convincing evidence that the other intended to deceive the PTO. Power Integrations, Inc. v. Fairchild Semiconductor Int’l Inc., et al., C.A. No. 08-309-LPS (D. Del. Apr. 25, 2013). The Court found that the inventor of the Defendant’s asserted patent “was generally aware of the existence of” two patents allegedly intentionally withheld from the PTO, but that “does not mean he also was aware of those patents’ specific disclosures.” Id. at 7. Quoting the Federal Circuit’s decision in Exergen Corp. v. Wal-Mart Stores, Inc., 575 F.3d 1312, 1330 (Fed. Cir. 2009), Judge Stark explained that “one cannot assume that an individual, who generally knew that a reference existed, also knew of the specific material information contained in that reference.” Id. at 8. Moreoever, the Court noted that the inventor believed his patent was “limited to frequency jitter on the primary side of a power converter,” whereas the allegedly withheld patents, “in [the inventor’s] mind, related to secondary side jitter control.” Id. Although the Court ultimately concluded that the inventor’s patent “was not limited to primary side applications, the Court’s subsequent conclusion does not render [the inventor’s] state of mind in 2004-2007 unreasonable . . . .” Id. Overall, the Court found the testimony of the defendant’s inventor to be credible, and therefore found that the plaintiff failed to show deceptive intent by clear and convincing evidence. Id. at 8-10.
The Court next addressed the defendant’s inequitable conduct defense, which was based on an alleged “misrepresentation” to the PTO during reexamination. Id. at 11. Specifically, the defendant argued that in response to a rejection during reexamination of certain claims as anticipated by a reference, the plaintiff argued that the reference “did not disclose a ‘maximum duty cycle signal provided by an oscillator,’” implicitly asserting that such an oscillator would be novel. Id. at 11-12. According to the defendant, such oscillators were well known in the art, and “the Examiner only withdrew the rejection because he mistakenly believed that an oscillator providing a maximum duty cycle was novel.” Id. at 12. The Court noted, however, that the plaintiff had disclosed other prior art referencing such oscillators, and in any event because the rejection was based on claims initially found to be anticipated, “[t]he arguments [the inventor] presented to the PTO were limited to the specific disclosure of the [specific] reference and focused on the differences between that reference and the claims.” Id. at 13. Accordingly, the Court found that no misrepresentation had been made to the PTO. Further, because the Examiner “identified an oscillator with a maximum duty cycle signal in at least one additional prior art reference,” the Court could not “conclude that the Examiner considered the oscillator to be a point of novelty.” Id. In short, the inventor “credibly testified that he believed the Examiner was aware that oscillators with maximum duty cycle signals were known in the prior art. . . . This belief is more than reasonable given that the Examiner expressly identified such an oscillator in the Office Action and signed several Information Disclosure Statements indicating that he considered the references [the Plaintiff] submitted that disclose this feature.” Id.