On March 15th, in a long-awaited ruling, the Fed. Cir. vacated a panel holding reversing a lower court’s finding that disputed means-plus-function claims met the written description requirement. The Fed. Cir. asked the parties and amici (and there will be many of them) to address the position adopted in the Cybor decision that interpretations of claim meaning and scope by a lower court are questions of law that are properly reviewed de novo by the Fed. Cir. without giving any deference to the fact-finding made by the lower court in support of its decision.
District Courts have long chafed under this decision since they are required to do all the work required to conduct a Markman hearing that may ultimately be completely disregarded by the Fed. Cir. when it reviews verdicts turning on claim construction–as most of them must. However, should even precise fact-finding trump basic rules of claim construction? The outcome of this en banc decision will be as important to patent law as KSR, Markman and Philips defined. In any case, that is what the scholars will be telling us for a year or two to come.