The US Court of Appeals for the Federal Circuit again reversed a district court’s summary judgment determination (on remand) that liability was precluded by intervening rights and found that district courts must account for the differences between claim construction standards when relying on the findings of an examiner during reexamination. Convolve, Inc. et al. v. Compaq Computer Corp., et al., Case No. 14-1732 (Fed. Cir., Feb. 10, 2016) (Hughes, J).

The present case was back before the Federal Circuit after a district court, on remand, granted summary judgment of no infringement a second time, albeit on alternative grounds. While the Federal Circuit affirmed the grant of summary judgment of no direct infringement by Seagate (one of the named defendants), it reversed the district court’s grant of summary judgment of non-infringement by Compaq on nine of the 12 claims, finding that the district court’s claim construction was unduly narrow. In reversing, the Federal Circuit addressed and reversed the district court’s grant of summary judgment based on a determination that liability was precluded by intervening rights.

The intervening rights doctrine states that a patentee of a patent that survives reexamination is only entitled to infringement damages for the time period between the date of issuance of the original claims and the date of the reexamined claims if the original and reexamined claims are substantially identical. In determining the scope of the “before and after” claims, the court must apply the traditional claim construction principles set forth in Phillips. Under this standard, the specification is the single best guide to the meaning of the claim terms. In addition to consulting the specification, the court should consider the patent’s prosecution history. Specifically, the court should pay attention to the examiner’s finding during reexamination. The examiner’s findings are not dispositive, however, as the court must account for the differences between the broadest reasonable interpretation standard and the Philips standard.

In this case, the patentee added the modifier “seek” to the claimed “acoustic noise” limitation during a reexamination proceeding. The question presented was whether the pre-reexamination claims were limited to “seek acoustic noise” or whether the original claims covered both seek and spindle acoustic noise. The Federal Circuit found that the addition of the word seek during reexamination did not alter the scope of the claims, as the pre-reexamination claims were already limited to seek acoustic noise.

The Federal Circuit found that the claims on their face recited only “acoustic noise,” which could encompass both seek and spindle acoustic noise. Looking at the specification, the Court noted that while the specification did not use the term seek acoustic noise, neither did it expressly exclude spindle acoustic noise. The Court concluded, however, that the specification was focused on the seek process and the noise it generates.

Next, the Federal Circuit examined the prosecution history before the reexamination and found that it limited the claimed acoustic noise to only seek acoustic noise. In making this determination, the Federal Circuit relied on an office action response where the applicant made it clear that the acoustic noise problems addressed by the claims and the specification were limited to those generated by the seek function, not the spindle motor. Then, examining the prosecution history of the reexamination, the Court found that it did not compel a different result.

Practice Note: In order to avoid intervening rights, it may be useful (when possible) to  characterize amendments made during reexamination as merely clarifying terms in accordance with their appropriate interpretation under Phillips.