Addressing the standard to establish a “clear and unmistakable” disclaimer of claim scope during prosecution, the U.S. Court of Appeals for the Federal Circuit reversed the district court’s narrow claim construction and remanded the case for a new trial. Avid Technologies, Inc. v. Harmonic, Inc., Case No. 15-1246 (Fed. Cir., Jan. 1, 2015) (Taranto, J.).

Avid Technologies asserted two patents against Harmonic, both of which relate to data storage systems that allow users to store and retrieve large files, such as movies. The systems included three categories of components: multiple storage units that store data; a client application, which reads data from and writes data to the storage units; and a central controller that can perform various facilitative functions. At trial, the dispute centered on two elements of the asserted claims: how the central controller communicated with the storage units, and how the storage units stored the data. The district court narrowly construed the first disputed element, based on what the court determined to be a disclaimer of claim scope during prosecution, and did not construe the second disputed element. The jury found the patents to be valid but not infringed, and Avid appealed the non-infringement finding based upon alleged error in the district court’s claim construction. Harmonic did not cross-appeal the finding of validity.

On appeal, the Federal Circuit reviewed the district court’s claim construction de novo, as it was based entirely on an intrinsic-evidence determination about the meaning of the prosecution history. The Court concluded that the district court’s narrow construction was improper because the statements Avid made during prosecution did not amount to a “clear and unmistakable” disavowal of subject matter, but instead were “amenable to multiple reasonable interpretations.” Further, because Harmonic did not dispute that its system satisfied the first claim element under Avid’s proposed (and Court confirmed) construction, the Federal Circuit found that “satisfaction of the element [was] now settled.” Instead of entering a judgment of infringement, however, the Court remanded the case for a new trial because, as the Court explained, the evidence did not compel a finding of infringement of the second disputed claim element. Specifically, because the district court had not construed the second disputed term, both Avid and Harmonic were unable to show that the jury was required to find infringement or non-infringement on this element.

Practice Note: This Court should serve as a warning to appellate practitioners that, to the extent possible, they should seek to preserve their alternative positions before the Federal Circuit.