Foreseeability as a Bar to Proof of Patent Infringement

The doctrine of equivalents is a rule of equity adopted more than 150 years ago by the U.S. Supreme Court. Prosecution history estoppel is a rule of equity that controls access to the doctrine. In May 2002, the Court was called upon to revisit the doctrine and the estoppel rule in <i>Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co. Ltd.</i> Ultimately the Court reaffirmed the doctrine and expanded the estoppel rule, but not without inciting heated debate over the Court's rationale &mdash; especially since it included a new and controversial foreseeability test in its analysis for estoppel.

22 minute read May 01, 2003 at 01:48 PM
By
Tim L. Burgess
Foreseeability as a Bar to Proof of Patent Infringement

The doctrine of equivalents is a rule of equity adopted more than 150 years ago by the U.S. Supreme Court. Prosecution history estoppel is a rule of equity that controls access to the doctrine.

This premium content is locked for LawJournalNewsletters subscribers only

ENJOY UNLIMITED ACCESS TO THE SINGLE SOURCE OF OBJECTIVE LEGAL ANALYSIS, PRACTICAL INSIGHTS, AND NEWS IN LawJournalNewsletters

  • Stay current on the latest information, rulings, regulations, and trends
  • Includes practical, must-have information on copyrights, royalties, AI, and more
  • Tap into expert guidance from top entertainment lawyers and experts

Already have an account? Sign In Now

For enterprise-wide or corporate access, please contact Customer Service at [email protected] or call 1-877-256-2473.

NOT FOR REPRINT

© 2026 ALM Global, LLC, All Rights Reserved. Request academic re-use from www.copyright.com. All other uses, submit a request to [email protected]. For more information visit Asset & Logo Licensing.

Continue Reading

Agentic AI introduces risks that are novel and complex, but the most effective response is a familiar one. Zero Trust answers the problem of when an AI agent misfires on its own by constraining what an agent can do rather than betting on how it will behave.

July 31, 2026

The outsourcing of office and administrative services is expected to grow 50%-60% in the next five years. Contrary to what decision-makers think, and what the service providers hope you think, the biggest risk in outsourcing isn't choosing the wrong provider. It's outsourcing the wrong process, under the wrong model, with the wrong performance measures and contract terms.

July 31, 2026