The Rest of the Story: The Supreme Court's Decision in Festo


On May 28, 2000, the United States Supreme Court issued its unanimous decision, written by Justice Anthony Kennedy, that the patent world had been anxiously awaiting.  In short, the doctrine of equivalents is alive.  The Supreme Court vacated the Federal Circuit’s judgment and remanded the case for further proceedings consistent with its opinion.    In agreement with the Federal Circuit, the Supreme Court held that prosecution history estoppel arises from any amendment that narrows a claim to comply with the Patent Act, not only from amendments made to avoid the prior art.   In other words, “[e]stoppel arises when an amendment is made to secure the patent and the amendment narrows the patent’s scope.”   Cosmetic amendments and other amendments concerning the form of the application do not narrow the patent’s scope and do not raise a prosecution history estoppel.

Email Disclaimer