On March 15, 2013, the Court of Appeals for the Federal Circuit agreed to rehear a case en banc to revisit an issue that has been percolating in the court for a number of years: what standard should the appellate court apply in reviewing decisions by trial courts on the meaning of claim terms? The case is Lighting Ballast Control LLC v. Phillips Electronic North America Corp. (2012-2014, 2015), and the Court of Appeals has asked the parties to submit briefing on the following issues, which are to be decided by all active members of the court:
(i) whether the court should overrule its decision in Cybor Corp. v. FAS Technologies, Inc., 138 F.3d 1448 (Fed. Cir. 1998);
(ii) whether the court should afford deference to any aspect of a district court’s claim construction; and
(iii) if deference is afforded, which aspects of a district court’s claim construction should be given deference.
In Lighting Ballast, the district court concluded that the claim term “voltage source means” was not a “means-plus-function” claim subject to 35 U.S.C. § 112, ¶ 6, because the district court concluded, on the basis of expert testimony in declaration form and deposition testimony, that the claim term itself denoted sufficient structure to the person of skill in the art. In construing the claim, the district court credited the testimony of Lighting Ballast’s experts and rejected the argument by the alleged infringer that the claim was indefinite for failing to recite a structure. Following a jury trial, Lighting Ballast’s patent was found infringed.
On appeal, a panel of the Federal Circuit Court of Appeals reversed the district court’s decision and held the disputed claim term, “voltage source means”, was indefinite and, therefore, invalid. Applying its standard of review in Cybor, the panel of the Court of Appeals reviewed the district court’s claim construction de novo, without any deference to the decision or the findings of fact made by the district court incident to its claim construction determination. By its order granting Lighting Ballast’s petition for rehearing en banc, the Court of Appeals has not vacated the panel decision holding the claim term indefinite. Briefing on the en banc issues is due to be filed over the next 90 days, but oral argument has yet to be scheduled.
Lighting Ballast presents the Court of Appeals’ first opportunity to revisit the standard of review applied to claim construction decisions since Cybor, which was issued 25 years ago. During that time period, all but one of the judges who make up the active bench of the Federal Circuit Court of Appeals have changed. A decision by the Court of Appeals changing the standard of review for claim construction determinations, an issue presented in nearly every patent action, would have widespread ramifications for patent litigation and the current uncertainty surrounding the likelihood of reversal of claim construction determinations by district courts.