What is the prosecution history of a patent?

In the U.S., a prosecution history of a patent (i.e., the proceedings between the patent applicant and the USPTO from application filing to patent issuance) comes into play in the context of claim construction (for example, before a district court, before the PTAB in a post-grant proceeding, or in the eyes of a third …

What is patent estoppel?

“Estoppel” in patent law is a legal term meaning that a second argument is barred if it is inconsistent with a first argument. In a patent context, it bars an inventor from admitting something to the Patent and Trademark Office and later contradicting that admission, whether before the PTO or before a court.

Is prosecution history estoppel an affirmative defense?

In cases in which the patent holder claims indirect infringement under the doctrine of equivalents, the defendant may raise prosecution history estoppel as an affirmative defense to block the infringement claims.

What does the term prosecution history estoppel mean?

Prosecution history estoppel, also known as file-wrapper estoppel, is a term used to indicate that a person who has filed a patent application, and then makes narrowing amendments to the application to accommodate the patent law, may be precluded from invoking the doctrine of equivalents to broaden the scope…

When did the Federal Court of Justice rule on estoppel?

More than a decade later, the Federal Court of Justice ruled on 14 June 2016 that statements made during prosecution may indicate how the skilled person construes a patent. At the same time, the Federal Court of Justice set forth that such indications must not readily be relied on as the sole basis of claim construction.

Is the prosecution history of a patent relevant?

Although primarily a U.S. 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 U.S.

Can a file wrapper estoppel be used in Canada?

Patents in Canada are subject to a purposive construction, which relies on reading both the claims and the specifications to determine the scope of a patent, and extrinsic evidence is not permitted. Therefore, the Canadian courts emphatically reject what they refer to as “file wrapper estoppel”.