Posts Tagged: assignor estoppel


Industry Commenters Say Minerva Ruling is a Win for Employee Mobility

Yesterday, the U.S. Supreme Court ruled 5-4 in Minerva Surgical, Inc. v. Hologic, Inc., Cytyc Surgical Products, LLC that the doctrine of assignor estoppel”—which bars …
By IPWatchdog
3 months ago 2

Assignor Estoppel: Can’t We Just Leave It To Congress? (Answer: Not Really)

On Wednesday, April 21, the U.S. Supreme Court heard oral arguments in Minerva Surgical, Inc. v. Hologic, Inc., which concerns the doctrine of assignor estoppel. Generally speaking, …
By William H. Milliken
5 months ago 2

Justices Lean Toward Limiting, Not Eliminating, Assignor Estoppel Doctrine in Minerva v. Hologic

The U.S. Supreme Court heard oral arguments today in Minerva Surgical, Inc. v. Hologic, Inc., Cytyc Surgical Products, LLC, which essentially asks the Court to decide …
By Eileen McDermott
5 months ago 2

NYIPLA Tells SCOTUS to Scrap CAFC’s ‘Per Se’ Approach to Assignor Estoppel in Minerva v. Hologic

Minerva Surgical, Inc. petitioned the Supreme Court of the United States (SCOTUS) in September 2020 to consider the question “whether a defendant in a patent infringement action who …
By La'Cee Conley
7 months ago 0

Supreme Court Will Review Doctrine of Assignor Estoppel

On Friday, the U.S. Supreme Court granted a petition for certiorari filed by Minerva Surgical, Inc. asking the Court to clarify questions around the doctrine of …
By Eileen McDermott
9 months ago 3

CAFC: Inability to Challenge Claims in District Court is No Impediment to PTAB Challenge

The CAFC explained that the doctrine of assignor estoppel does not bar an assignor from filing a petition for IPR to challenge the validity of the assigned …
By Rebecca Tapscott
1 year ago 1

Assignor Estoppel and IPRs: Possible Impact of Arista v. Cisco on Employment or Assignment Agreements

The doctrine of assignor estoppel has been around for over a century and most often applied in the U.S. International Trade Commission (ITC) and U.S. …
By J. Derek Mason
3 years ago 2

Federal Circuit says Assignor Estoppel Has “No Place” in IPR Proceedings

The Federal Circuit recently found that assignor estoppel has “no place in IPR proceedings,” affirming a holding of the Patent Trials and Appeal Board (“Board”) that assignor …

Hologic Wins $4.8M in Jury Verdict After Judge Determines Assignor Estoppel BarredPatent Invalidity Defenses

On July 27th, a jury verdict entered in the District of Delaware awarded $4.8 million in lost profit and reasonable royalty damages to Marlboro, MA-based medical technology company …
By Steve Brachmann
3 years ago 0

Mentor Graphics v. Synopsys: Affirmed-in-Part, Reversed-in-Part, Vacated-in-Part, and Remanded

Various Synopsys parties and EVE-USA, Inc. (collectively “Synopsys”) sued Mentor Graphics, seeking a declaration that Mentor’s ’376, ’531, and ’176 patents were invalid and not infringed. Mentor counterclaimed for …

Federal Circuit Affirms District Court on Finding of Assignor Estoppel

The Court affirmed that B/E could not challenge the validity of MAG’s patents, because of assignor estoppel. In this case, MAG acquired the patents by …

Semiconductor Energy Laboratory v. Yujiro Nagata: Assignor Estoppel is Affirmative Defense, No Supplemental Jurisdiction

Semiconductor Energy Laboratory (“SEL”) appealed the decision of the District Court of California that dismissed with prejudice SEL’s complaint versus Yujiro Nagata (“Nagata”) due to a …
By Jason Williams
9 years ago 0