Continuation application

Under United States patent law, a continuing patent application is a patent application that follows, and claims priority to, an earlier-filed patent application.

A continuing patent application may be one of three types: a continuation, divisional, or continuation-in-part. Although continuation and continuation-in-part applications are generally available in the U.S. only, divisional patent applications are also available in other countries, as such availability is required under Article 4G of the Paris Convention.

From 1838 to 1861, inventors could file patent applications on improvements to their inventions. These were published as "additional improvement patents" and were given numbers preceded by "A.I.". About 300 of these patents were issued.

Under the law in the U.S., inventors may file several different types of patent applications to cover new improvements to their inventions or to cover different aspects of their inventions. These types of patent applications include "continuation", "divisional", "continuation in part", and "reissue".

A "continuation application" is a patent application filed by an applicant who wants to pursue additional claims to an invention disclosed in an earlier application of the applicant (the "parent" application) that has not yet been issued or abandoned. The continuation uses the same specification as the pending parent application, claims the priority based on the filing date of the parent, and must name at least one of the inventors named in the parent application. This type of application is useful when a patent examiner allowed some, but rejected other claims in an application, or where an applicant may not have exhausted all useful ways of claiming different embodiments of the invention.

During the prosecution of a continuation application, the applicant may not add additional disclosure to the specification. If the inventor needs to supplement the disclosure of the earlier parent application, he has to file a continuation-in-part application.

In the typical case, a patent examiner will examine patent claims and amendments in an original patent application for two rounds of "office actions" before ending examination. However, often two office actions are not enough to resolve all of the issues in the patent prosecution.

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