Prosecution disclaimer
Encyclopedia
Under United States patent law
a prosecution disclaimer is a statement made by a patent applicant during examination
of a patent application
which can limit the scope of protection provided by the resulting patent
. It is one type of file-wrapper estoppel, the other being prosecution history estoppel
.
Prosecution disclaimer ensures that an applicant cannot obtain a patent by arguing that its claimed invention is narrow, and then turn around and enforce that patent against competitors with an argument that it is broader.
doctrine that originates in federal court precedent. One discussion and example of prosecution disclaimer is made in the Federal Circuit case Southwall Techs. Inc. v. Cardinal IG Co. This case also cites several other Federal Circuit cases dealing with prosecution disclaimer.
In Southwall, the Court was explicit in defining the principle: "The prosecution history limits the interpretation of claim terms so as to exclude any interpretation that was disclaimed during prosecution". The Court used the principal to prevent the patentee from arguing an interpretation of "sputter deposited dielectric" that would allow it to continue with a patent infringement suit, because the argument was inconsistent with its position during prosecution.
The Court also noted that a given claim term must be interpreted consistently across all claims. Once a term has been given a specific meaning with regard to one claim, the same meaning applies to all claims that include that term.
Another Federal Circuit case using the term "disclaimer" is Standard Oil Co. v. American Cyanamid Co. In Standard Oil, the Court stated that "the prosecution history (or file wrapper) limits the interpretation of claims so as to exclude any interpretation that may have been disclaimed or disavowed during prosecution in order to obtain claim allowance."
, where claim amendments limit a patentee's ability to apply the doctrine of equivalents
, prosecution disclaimer limits the literal scope of the claims and results from applicant argument, rather than amendments. In Loctite Corp. v. Ultraseal Ltd, the judge said that "interpreting claims in view of the prosecution history applies as a preliminary step in determining literal infringement. Prosecution history estoppel applies as a limitation to the doctrine of equivalents after the claims have been properly interpreted and no literal infringement is found".
Even if the literal scope of a claim is narrowed by prosecution disclaimer, the doctrine of equivalents may still be available for the claim terms at issue.
United States patent law
United States patent law was established "to promote the Progress of Science and useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries;" as provided by the United States Constitution. Congress implemented these...
a prosecution disclaimer is a statement made by a patent applicant during examination
Patent prosecution
Patent prosecution describes the interaction between applicants and their representatives, and a patent office with regard to a patent, or an application for a patent...
of a patent application
Patent application
A patent application is a request pending at a patent office for the grant of a patent for the invention described and claimed by that application. An application consists of a description of the invention , together with official forms and correspondence relating to the application...
which can limit the scope of protection provided by the resulting patent
Patent
A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....
. It is one type of file-wrapper estoppel, the other being prosecution history estoppel
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 narrowing amendments to the application to accommodate the patent law, may be precluded from invoking the...
.
In practice
Whenever an applicant makes a clear and unambiguous argument that a claim does not cover a certain feature, this argument becomes binding on the applicant and the applicant cannot later argue in court that the claim would cover such a feature. Coverage of that feature is considered "disclaimed" by the applicant and cannot be recovered. The scope of the resulting patent is narrower than it might be if the applicant had said nothing.Prosecution disclaimer ensures that an applicant cannot obtain a patent by arguing that its claimed invention is narrow, and then turn around and enforce that patent against competitors with an argument that it is broader.
Historical basis and case law
Prosecution disclaimer is a common lawCommon law
Common law is law developed by judges through decisions of courts and similar tribunals rather than through legislative statutes or executive branch action...
doctrine that originates in federal court precedent. One discussion and example of prosecution disclaimer is made in the Federal Circuit case Southwall Techs. Inc. v. Cardinal IG Co. This case also cites several other Federal Circuit cases dealing with prosecution disclaimer.
In Southwall, the Court was explicit in defining the principle: "The prosecution history limits the interpretation of claim terms so as to exclude any interpretation that was disclaimed during prosecution". The Court used the principal to prevent the patentee from arguing an interpretation of "sputter deposited dielectric" that would allow it to continue with a patent infringement suit, because the argument was inconsistent with its position during prosecution.
The Court also noted that a given claim term must be interpreted consistently across all claims. Once a term has been given a specific meaning with regard to one claim, the same meaning applies to all claims that include that term.
Another Federal Circuit case using the term "disclaimer" is Standard Oil Co. v. American Cyanamid Co. In Standard Oil, the Court stated that "the prosecution history (or file wrapper) limits the interpretation of claims so as to exclude any interpretation that may have been disclaimed or disavowed during prosecution in order to obtain claim allowance."
Jurisdictions other than the United States
The doctrine of prosecution disclaimer does not exist in other jurisdictions, such as Europe. In those jurisdictions, claim language stands on its own without reference to the prosecution history of the application.Comparison with prosecution history estoppel
Unlike prosecution history estoppelProsecution 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 narrowing amendments to the application to accommodate the patent law, may be precluded from invoking the...
, where claim amendments limit a patentee's ability to apply the doctrine of equivalents
Doctrine of equivalents
The doctrine of equivalents is a legal rule in most of the world's patent systems that allows a court to hold a party liable for patent infringement even though the infringing device or process does not fall within the literal scope of a patent claim, but nevertheless is equivalent to the claimed...
, prosecution disclaimer limits the literal scope of the claims and results from applicant argument, rather than amendments. In Loctite Corp. v. Ultraseal Ltd, the judge said that "interpreting claims in view of the prosecution history applies as a preliminary step in determining literal infringement. Prosecution history estoppel applies as a limitation to the doctrine of equivalents after the claims have been properly interpreted and no literal infringement is found".
Even if the literal scope of a claim is narrowed by prosecution disclaimer, the doctrine of equivalents may still be available for the claim terms at issue.