The Court of Appeals for the Federal Circuit affirmed the need for corresponding structure to be set forth in the specification to support a means-plus-function claim in order to avoid indefiniteness.  Function Media appealed the district court’s finding that a method claim was indefinite for lack of corresponding structure in the specification.  The Federal Circuit held that a patentee cannot rely on what is knowledge of one skilled in the art to fill in the gaps left by a lack of structure.

Function Media, LLC V. Google, Inc.