On Friday, a divided Federal Circuit confirmed that it will continue to apply a de novo standard of review to claim construction and rejected calls to give more deference to district court decisions.  Lighting Ballast Control, LLC v. Philips Elecs. et al. (No. 2012-1014) (Fed. Cir. Feb. 21, 2014).

The de novo review standard has been much-criticized since the Federal Circuit first put it in place in 1998.  Most notably, it has been blamed for needlessly adding cost and uncertainty to patent litigation.  Litigants frequently go all the way through a costly patent trial, only to have the Federal Circuit revise the claim construction, forcing the parties to start over in district court.  Reflecting the divisive nature of the de novo standard, this case generated a flurry of amici briefs—21 from 38 different organizations.  The amici briefs were divided, with the Patent and Trademark Office, the American Bar Association, and other academics urging a revision of the standard, while some industry amici, such as Google, Amazon, and Yahoo!, urged its retention in the name of certainty.

In a 6-4 en banc decision, the Federal Circuit decided to stick with the established rule—that a district court’s interpretation of claim language is primarily legal and is afforded no deference on appeal.  The Federal Circuit justified its decision by citing the need for “consistency and stability” in the law. It noted that the approach of the last 15 years—de novo review—has not been proved to be “unworkable” and moreover no “consensus” has emerged as to how to fix its perceived flaws.  Thus, the Federal Circuit felt it prudent to apply the principal of stare decisis.

It appears that, for the time being, parties can expect the Federal Circuit’s frequent reversal or revision of district courts’ claim constructions to continue—unless a Supreme Court that has shown an increased interest in patent cases grants a likely petition for a writ of certiorari.