In general a complete or non-provisional patent application covering a single
invention is filed, reviewed by an examiner and either allowed or rejected.
However,
in
some cases
it may
be desirable to file a continuation patent. A continuation patent application
provides no new information about the invention to
be patented
(referred to
as the “disclosures”);
rather, a continuation application typically broadens the “claims” of the application,
which are the aspects of the invention for which patent protection is sought.
The need for
a continuation
application often arises when a patent application is rejected because the
claims are overly broad and seek protection for aspects of an invention that
may not be patented for one reason or another. In such a case, the patent applicant
will narrow the claims of the original patent in order to satisfy the patent
examiner and then refine the broader claims in the continuation application.
The advantage of a continuation application is that it takes the priority date
that was established by the original (“parent”) application and maintains the
pendency of the patent application during the review process.
A valid continuation application must be filed while the parent application is still pending; thus, a continuation application may not be filed if a patent has been issued under the original application or if the application has been rejected, abandoned, or otherwise terminated. The parent application is still pending if the original application or any previous continuation application is still pending.
A related type of modification to a patent application is called a “continuation-in-part” application, which unlike a continuation application contains new disclosures, or information defining the invention. New claims that are supported by the original disclosures will benefit from the original application’s filing date; however, new claims that depend upon the additional disclosures do not benefit from the original filing date. The claims based on any new disclosures are considered a new patent application and thus receive their own priority date as of the date that the continuation-in-part application is filed.
Another type of continuation application is the divisional application. A divisional application is necessary when the U.S. Patent and Trademark Office (USPTO) determines that a patent application contains more than one distinct invention and issues a restriction requirement, which requires the patent applicant to choose which of the distinct inventions is to be included in the patent application. A new and separate divisional application can be filed for each of the additional distinct inventions at any time while the original application is pending. This mechanism ensures that the USPTO is not overburdened by patent applicants who attempt to patent multiple inventions under one application in order to avoid application fees. As with an ordinary continuation application, the divisional applications receive the same priority date as the original application.