Federal Circuit, September 5, 2014, 2013-1330

Pegasus sued EPOS alleging the infringement of several patents related to digitized pens. The district court granted summary judgment of noninfringement for all of the patents.

Claim construction is a legal statement of the scope of the patent right, which the Federal Circuit reviews de novo. Claim terms are given their ordinary and customary meaning as understood by a person of ordinary skill in the art. Summary judgment is appropriate when there is no genuine dispute as to any material fact and the movant is entitled to judgment as a matter of law.

For five of the six patents, the Federal Circuit found that the district court erroneously applied the rules of claim construction and that the district court erred by granting summary judgment. Therefore, on those five patents, the Federal Circuit vacated and reversed the district court's findings of noninfringement.

For the sixth patent, US 6,724,371, Pegasus appealed the district court's grant of summary judgment of noninfringement under the doctrine of equivalents.

When addressing the doctrine of equivalents, a court must ask whether an asserted equivalent is an "insubstantial difference" from the claimed element, or whether it matches the "function, way, and result of the claimed element."

In this case, the pertinent claim language reads, "within the housing, remote from the drawing tip, yet in close proximity…[and] the device being for receiving or transmitting an intermittent ultrasound signal." The district court interpreted the term intermittent to mean "noncontinuous." In other words, the district court held that allowing "continuous ultrasound signals" to be equivalents of "intermittent ultrasound signals" would "eliminate the intermittent limitation entirely." Therefore, the district court granted summary judgment of noninfringement under the doctrine of equivalents.

The Federal Circuit disagreed. The Federal Circuit cautioned courts making determinations under the doctrine of equivalents to "not shortcut the inquiry by identifying a binary choice in which an element is either present or not present." The Federal Circuit held that, in this case, the district court shortcut the inquiry by identifying a binary choice between continuous or intermittent.

Accordingly, the Federal Circuit vacated and remanded to the district court for the court to reconsider the issue.