IP Law Daily Computer network system patentee not estopped from changing list of inventors
Friday, August 28, 2020

Computer network system patentee not estopped from changing list of inventors

By Kevin M. Finson, J.D.

Judicial estoppel did not prevent a change to a patent’s list of inventors because the proposed change was consistent with the court’s claim determination and did not contradict a position previously taken before a court or other tribunal.

The owner of a patent for a computer network system should not have been precluded by a district court from modifying the list of inventors in its asserted patent, the U.S. Court of Appeals for the Federal Circuit has held. The patentee had removed an inventor during an inter partes review proceeding in what appeared to be an attempt to claim a priority date before that inventor was hired, then sought to add him back to the list of inventors after the trial court’s claim determination found this person was an inventor. The trial court subsequently invalidated the patent for not listing all inventors. However, the appellate court decided that judicial estoppel did not bar the patentee from adding an inventor to match the district court’s construction of a key claim term, which involved a structure for which the additional inventor was responsible (Egenera, Inc. v. Cisco Systems, Inc., August 28, 2020, Prost, S.).

Patent-in-suit. Egenera, Inc., owned a patent for a platform for automatically deploying a scalable and reconfigurable virtual network. This included, among other things, "at least one control node . . . including logic to modify . . . received messages to transmit said modified messages to the external communication network." The control node logic was to take messages created by processors inside the network and modify them so that they would be understandable to computers outside the network.

Infringement action; review proceeding. In August 2016 Egenera sued Cisco Systems, Inc. (Cisco) for infringement of that patent. Cisco filed a petition for inter partes review (IPR), which was denied by the Patent Trial and Appeal Board. After the IPR petition was filed, Egenera indicated that upon review it had determined that one of the listed inventers, Peter Schulter, had been hired after all the claim limitations had been conceived, and separately petitioned the USPTO to remove him as an inventor. The USPTO allowed this petition. The district court later found that the "logic to modify" language in the patent application was means-plus-function language under 35 U.S.C. § 112(f), and that the corresponding structure to that function was the so-called tripartite structure—the combination of a virtual LAN proxy, a physical LAN driver, and a virtual LAN server. The court also found that Schulter was an inventor of that tripartite structure. As a result, the trial court held the patent was invalid for failing to list all inventors and refused to allow Egenera to add Schulter as an inventor again because Egenera was judicially estopped by its previous petition removing Schulter from the list of inventors.

Means-plus-function analysis. The court found that 35 U.S.C. § 112(f) applied to the claims for "logic to modify." The word "logic" was being used as a generic "black box" referring back to some structure without actually explaining what that structure was. The three components of the tripartite structure—virtual LAN proxy, physical LAN driver, and virtual LAN server—all functioned in concert to carry out the function described, namely, modifying messages travelling outside the virtual network so that they would be understandable to computers outside the network. There was no dispute that Schulter was an inventor of the tripartite structure, so for that reason the Federal Circuit affirmed the claim construction of the trial court, determining that Schulter should have been listed as an inventor on the patent application.

Judicial estoppel. The court then turned to the question of whether Egenera could now modify its patent application to re-list Schulter as an inventor, despite having already removed him. The court determined that Egenera had not advanced clearly inconsistent positions. When Egenera contended that Schulter was not an inventor, it also contended that the tripartite structure for which he was responsible was not part of the claimed invention. It was only upon a judicial determination that the tripartite structure was in fact part of the claim that Egenera attempted to change the list of inventors to match the court’s claim construction. Additionally, the procedure Egenera followed to have Schulter removed from the list of inventors was not a judicial one, or even a court-like administrative proceeding, but was merely a ministerial correction of which no substantive analysis was done by the USPTO. Finally, the court noted that no prejudice would result from refusing to deem Egenera estopped from correcting the list of inventors to match the claim construction which had been imposed by the trial court. For that reason, the appellate court overturned the trial court’s decision on judicial estoppel and remanded for further proceedings.

This case is No. 19-2015.

Attorneys: Dan L. Bagatell (Perkins Coie LLP) for Egenera, Inc. E. Joshua Rosenkranz (Orrick, Herrington & Sutcliffe LLP) for Cisco Systems, Inc.

Companies: Egenera, Inc.; Cisco Systems, Inc.

MainStory: TopStory Patent GCNNews FedCirNews

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