Patent Glossary PQ

The Patent Glossary P for the letters P and Q. So what is patent prosecution, prior art, or a provisional patent?

patent pending

A phrase that often appears on manufactured items. It means that someone has applied for a patent on an invention that is contained in the manufactured item. It serves as a warning that a patent may issue that would cover the item and that copiers should be careful because they might infringe if the patent issues. Once the patent issues, the patent owner will stop using the phrase "patent pending" and start using a phrase such as "covered by U.S. Patent Number XXXXXXX." Applying the patent pending phrase to an item when no patent application has been made can result in a fine.


The inventor to whom the patent is granted and all persons to whom the patent is subsequently assigned. The term is slightly broader than the owner of the patent as the inventor would still be considered a patentee even if he or she has assigned his or her invention to someone else.


The formal introductory clause of a patent claim. Depending on the circumstances, the preamble may or may not define a narrowing element of the claim. The preamble usually only defines the setting or context in which the elements of the claim appear. As a Jepson claim preamble sets forth the setting of the new invention, the use of Jepson format results in an implied admission that what is recited in the preamble is known in the prior art.

preferred embodiment

The preferred embodiment of an invention can usually be interpreted as being recited as the best mode known to the inventor of carrying out the invention.

presumption of validity

A presumption created by statute that a patent is legitimate and sound-in-law. The burden of establishing that a patent is invalid is always on the challenger. The burden of proof on the challenger is to prove invalidity by clear and convincing evidence.

prior art

The existing body of technological information against which an invention is judged to determine if it is patentable as being novel and non-obvious. It must be early enough in time to be cited against the application.

prior-art statement

Also known as an information disclosure statement,or IDS, this is a document filed in the U.S. Patent and Trademark Office by the applicant during the prosecution of a patent application. The statement lists the prior art known by the applicant and/or his or her attorneys that is thought by them to be material to the patentability of the claims.

provisional application

In the US patent office an applicant can file a patent specification complying with U.S. disclosure standards and get the filing date as a priority date for a complete patent application filed within one year thereafter claiming the benefit. The provisional application does not have to contain claims. The effective filing date of the full application for purposes of avoiding prior art will be the filing date of the provisional application, but will have the benefit of the date of filing the full application for purposes of the 20 year patent term.


The administrative process of obtaining a patent from the U.S. Patent and Trademark Office. Prosecution includes filing the application with the U.S. Patent and Trademark Office, office actions, amending the application in response to objections and rejections from the examiner, responding to objections and rejections without amendment to the application, telephone and personal interviews with the examiner, appeals, and timely payment of the appropriate fees.

prosecution history estoppel

When one amends an application during the course of prosecuting a patent application to overcome a prior art rejection by narrowing the claims, one is precluded or estopped from asserting a broader interpretation after the patent issues. This type of estoppel clearly exists in the face of a prior art rejection, but can also exist based upon comments made in writing by the applicant and any other representations, causing one to conclude that the U.S. Patent and Trademark Office relied on certain representations regarding scope of claim in allowing the application. Under current law, file wrapper estoppel does not necessarily totally preclude the use of the doctrine of equivalents in the assertion of an infringement claim, but does substantially restrict the application of the doctrine of equivalents.

public use

A public or commercial use of an invention. If the public use occurred more than one year before the filing date of the patent application, obtaining a U.S. patent would be barred. If a use is experimental, then it is not a public use. Sometimes experimental use is referred to an exception to the public-use bar.Links



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Mike Ervin
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