Amendment To Inventorship Of Patent In Patent Office Does Not Judicially Estop Later Reversal Of Amendment To Inventorship

  • November 5, 2020

By: Gregory K. Gerstenzang

Egenera, Inc. V. Cisco Sys., Inc., No. 19-2015 (Fed. Cir. Aug. 28, 2020)

In Egenera the Federal Circuit held that a petition a company’s petition to remove an inventor from a patent did not judicially estop that company from adding the inventor back to the patent after a later claim construction order and trial on inventorship.

Egenera sued Cisco in the United States District Court for the District of Massachusetts, for infringement of Egenera’s patent directed to a platform for deploying a scalable and reconfigurable virtual network. Prior to claim construction in the District Court, Egenera petitioned the USPTO to remove an inventor from the ’430 patent. The USPTO granted the inventorship petition and removed the inventor from patent. After the inventorship petition was granted, the District Court issued a decision on claim construction and held in a trial on inventorship that found the removed inventor was a true inventor of the claimed matter of the ’430 patent. Egenera then asked the District Court to add the removed inventor back to the patent. The District Court held that judicial estoppel prevented Egenera from relisting the inventor and that the ’430 patent was invalid for failing to name all inventors.

Section 256 of the Patent Act allows for the amendment of inventorship of a patent if through error a person is named as an inventor, or if through error an inventor is not named. Under Federal Circuit precedent, a patent cannot be invalidated over inventorship as long as the inventorship issue can be corrected.

The Federal Circuit found that Egenera was not judicially estopped from adding the inventor back to the patent. Specifically, the court found that the prior removal of the inventor was not inconsistent with adding the inventor back to the patent because until claim construction was performed it was not clear that the removed person was an actual inventor. Egenera did not succeed in persuading a court to accept the earlier position that the removed person was not an inventor because the petition to correct inventorship in the USPTO ministerial in nature and was granted without any adjudication as to the merits as to the change in inventorship. Further, Cisco had not established that Egenera would derive an unfair advantage or impose an unfair detriment on Cisco if not estopped.

Key Takeaway:

Judicial estoppel does not apply to positions taken by a party after taking an inconsistent position during ministerial proceedings in the USPTO in which the position is not adjudicated, especially if a change in circumstances after the proceedings in the USPTO clarified that the prior position was incorrect.


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