There are times when a first-filed patent application discloses patentable subject matter that has not been successfully claimed at the end of the prosecution of the first-filed application. A second application containing substantially the same disclosure of the first-filed application may be filed seeking to claim such subject matter as long as the first-filed application is still pending and a proper claim of priority is made back to the first-filed application. Such a second-filed application is called a "continuation application". This post discusses some of the reasons behind pursuing continuation patent applications.

The desirability of a continuation application most often arises when the patent examiner does not agree to issue a patent with claims having the scope of coverage the applicant believes he or she is entitled to. Filing a continuation application allows an applicant to get a first early patent issued with claims having more limited coverage than the patent examiner agrees to, and then continue fighting for the broader coverage in the continuation application.

The original patent application is referred to as the parent and a continuation application of the parent application is referred to as a child. The child patent application of a parent application can itself have a child application (i.e. a continuation is filed for the child application). There is no legal limit on the number of continuation applications that can be filed. Accordingly, an original patent application can have a child application, grand-child application, great grand-child application and so on.

The reason a continuation application is filed instead of simply an independent unrelated application having the same disclosure is to be entitled to the priority date of the parent patent application. This is valuable because it helps to avoid rejections based on references having later dates than the parent application filing date, or rejections that may be based on the parent application itself being considered “prior art”.

There are two types of continuation applications:

REASONS TO FILE A CONTINUATION APPLICATION

As mentioned above a first reason to file a continuation application is to obtain additional patents that claim different scopes of protections for an invention disclosed in the original patent application. The different scope can be broader or narrower. Having such different patents makes it harder for competitors to design around or invalidate all of the patent claims that could be asserted against them if they try to copy the invention.

In line with the first reason, a second reason to file a continuation is to maintain the ability to seek the issuance of new patents that claim the invention in ways that are better suited to enforcement against competitors in the marketplace. When a patent application is pending, the scope of all the claims that could issue is indeterminate. This prevents competitors from knowing exactly how to avoid infringing claims that may issue in the future from a continuation application. When a patent issues its claims must by law lay out the clear boundaries of that patent. A patent attorney can assist a competitor in designing around the claims of an issued patent to avoid infringement of that patent. However, if a continuation is pending, then there is uncertainty for claims that have not yet issued. This can deter competitors from attempting to design around.

A third reason to file a continuation is to put a patent portfolio in a more attractive condition for licensing or sale (a patent portfolio is often a significant asset for a company). A potential licensee or purchaser may be more interested in a patent family that includes at least one issued patent and at least one pending continuation application. An issued patent demonstrates that the invention disclosed in the application is patentable. A pending continuation enables a licensee of purchaser to take the patent claims in a direction the licensee or purchaser wants to go. This is a desirable situation in patent monetization.

DEADLINE TO FILE A CONTINUATION APPLICATION

A continuation application must be filed before the patenting or abandonment of or termination of proceedings on the first application or on an application similarly entitled to the benefit of the filing date of the first application. Accordingly, in most cases a decision to file a continuation application should be made well in advance of the parent application issuing as a patent or becoming abandoned.

For more information about continuation applications please discuss the matter with attorney David M. Kleiman.