Prosecution history estoppel

Prosecution history estoppel, also known as file-wrapper estoppel, is a term used in United States patent law to indicate that a person who has filed a patent application, and then makes amendments to the application to accommodate the patent law, has no cause of action for infringement to the pre-amendment patent claims that were amended.

Although primarily a US term, questions of whether, or the extent to which the prosecution history should be relevant for determining the extent of protection of a patent also arise outside the US.Patent World, June 2007, "For the record" analysis by Richard Ebbink]

United States

The defining case on prosecution estoppel in the United states is "Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co.".

Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co.

Court of Appeals for the Federal Circuit Holding

In November 2000, the Court of Appeals for the Federal Circuit set a complete bar rule. This complete bar rule completely prohibited a patent owner from asserting the doctrine of equivalents for certain elements of his claim in instances where, during his patent prosecution he files:
# an amendment that narrows the scope of a claim for any reason related to the statutory requirements for a patent will give rise to a complete bar with respect to the amended claim element;
# a "voluntary" claim amendment that narrows the scope of the claim for a reason related to the statutory requirements for a patent will give rise to prosecution history estoppel as to the amended claim element; and
# an amendment and fails to explain the reasons for the amendment during prosecution of his patent.

Supreme Court reversal

The Supreme Court, citing the instruction in "Warner-Jenkinson Company, Inc. v. Hilton Davis Chemical Co." that "courts must be cautious before adopting changes that disrupt the settled expectations of the inventing community," overturned the complete bar issued by the Federal Circuit. It also acknowledged that while any narrowing amendment made for a reason related to patentability could give rise to prosecution history estoppel, inventors who amended their claims under the previous case law had no reason to believe that they were conceding all equivalents of amended elements when responding to a rejection. Had they known, the Court stated, they might have appealed the rejection.

With this policy in mind, the Court stated that it preferred a presumptive bar approach to the doctrine of equivalents. This presumptive bar approach holds that where claims are amended, "the inventor is deemed to concede that the patent does not extend as far as the original claim" and the patentee has the burden of showing that the amendment does not surrender the particular equivalent. To succeed, then, the patentee must establish that:
# the equivalent was unforeseeable at the time the claim was drafted;
# the amendment did not surrender the particular equivalent in question; or
# there was some reason why the patentee could not have recited the equivalent in the claim.

Canada

Free World Trust v. Électro Santé Inc. (2000)

This leading case in Canada on the issue of file wrapper estoppel, confirmed the emphatic rejection of this doctrine in Canada, as seen in previous cases, such as "Lovell Manufacturing Co. v. Beatty Bros. Ltd. (1962)". In Canada, no distinction is drawn in this regard between cases involving allegations of literal infringement and those involving substantive infringement. This means that the negotiations that have taken place between the patentee and the Patent Office cannot be used in order to establish a particular equivalent. Similarly, a patentee is barred from using any previous negotiations with the Patent Office in order to determine the scope of the claims of the patent (i.e. the negotiations cannot be used by the patentee or against the patentee in determining the scope of the claims within the patent).

Europe

Germany

The German Supreme Court, the Bundesgerichtshof, clarifyme ruled in 2002 that "For the determination of the extent of protection of a patent, occurrences in the examination proceedings which preceded the grant in principle are irrelevant". [BGH, 12 March 2002, Kunststoffrohtreil]

United Kingdom

The UK Courts have ruled that use of the examination file in aiding construction of a patent should be discouraged [House of Lords, 4 October, 2004, Kirin-Amgen v. Hoescht-Marion-Roussel] except where that file includes "objective information about and commentary on experiments". [UK Court of Appeal, 22 August 2001, Rohm & Haas v. Colla]

Ireland

The Irish Supreme Court has ruled that "evidence from the file which reflects the views of the patentee as to the construction of the claims is inadmissible". [Irish Supreme Court, 2 December 2005, Ranbaxy v. Warner-Lambert]

Netherlands

The Dutch Supreme Court has effectively come to the opposite conclusion to most other countries in Europe. The Dutch Supreme Court has stated that where "a third party invokes the examination file in the course of confirming the interpretation defended by him of a patent, it cannot be seen that that requirement [the reasonable doubt threshold] would force any restriction on involving public data from the examination file with the interpretation of the patent". [Hoge Raad, 22 December 2006, Dijkstra v Saier]

References

ee also

* Prosecution disclaimer