Plaintiff Parkervision, Inc. filed a patent infringement action against Qualcomm. Qualcomm answered the complaint and alleged an affirmative defense of inequitable conduct and a counterclaim that included a claim for inequitable conduct. Parkervision moved to strike the affirmative defense and the counterclaims pertaining to inequitable conduct, among other defenses and claims.

As explained by the district court, "Qualcomm counterclaims that ParkerVision's '551 patent is unenforceable due to ParkerVision's inequitable conduct and that the other five ParkerVision patents -- '518, '371, '734, '342, and '845 -- are also unenforceable because they stem from the '551 patent. (Doc. No. 91, ¶¶ 69-116.) All six of the inequitable conduct counterclaims thus rest on the factual allegations regarding the '551 patent. Specifically, Qualcomm sets forth three theories of inequitable conduct, alleging that Michael Q. Lee, the '551 patent's prosecuting attorney, and David F. Sorrells, an inventor: (1) "buried" the Patent and Trademark Office ("PTO") with references; (2) belatedly disclosed a material reference to the PTO; and (3) materially misrepresented four references to the PTO. Qualcomm urges the Court to consider the alleged inequitable conduct cumulatively, as a "course of deliberate egregious misconduct." (Id. ¶ 35.)"

Next, the district court addressed the standards for an inequitable conduct defense or counterclaim after Therasense. 'To prevail on the defense of inequitable conduct, the accused infringer must prove that the applicant misrepresented or omitted material information with the specific intent to deceive the PTO. . . . The accused infringer must prove both elements -- intent and materiality -- by clear and convincing evidence.' Therasense, Inc. v. Becton, Dickinson & Co., 649 F.3d 1276, 1287 (Fed. Cir. 2011) (citation omitted). Specific intent to deceive must be "the single most reasonable inference able to be drawn from the evidence. Id. (quoting Star Scientific, Inc. v. R.J. Reynolds Tobacco Co., 537 F.3d 1357, 1366 (Fed. Cir. 2008)). Materiality is but-for materiality. Id. at 1291. When an applicant fails to disclose prior art to the PTO, that prior art is but-for material if the PTO would not have allowed a claim had it been aware of the undisclosed prior art. Id."

With that standard in mind, the district court discussed the allegations of "burying" raised by Qualcomm in support of the inequitable conduct defense. "Qualcomm alleges that ParkerVision, through Lee and Sorrells, 'buried' the PTO examiner 'with hundreds of references so as to distract his attention from highly relevant references.' (Doc. No. 91, ¶ 12.) Qualcomm claims that beneath the numerous references provided to the PTO 'were a handful of highly relevant references . . . that, if they had been called to the [e]xaminer's full attention, would have precluded issuance of the pending claims.' (Id.)"

The district court then determined that specific intent could not be inferred merely from the allegations of burying and that the theory, therefore, failed as a matter of law. "Qualcomm's assertions that ParkerVision provided voluminous references in order to 'distract' the PTO examiner cannot meet this standard. Taking into account the practice of bringing inequitable conduct claims against a patentee for under-disclosing references, an equally if not more reasonable inference is that ParkerVision aimed to insulate itself from such claims by over-disclosing references. See Therasense, 649 F.3d at 1287 (noting that specific intent to deceive must be 'the single most reasonable inference able to be drawn from the evidence' (quoting Star Scientific, Inc. v. R.J. Reynolds Tobacco Co., 537 F.3d 1357, 1366 (Fed. Cir. 2008) (internal quotation marks omitted)). Because specific intent to deceive is not the only or single most reasonable inference to be drawn from the disclosure of voluminous references to the PTO, Qualcomm's pleading of the 'burying' theory fails as a matter of law."

ParkerVision, Inc. v. Qualcomm Incorporated, Case No. 3:11-cv-719-J-37TEM (M.D. Fla. Jan. 22, 2013)