Original U.S. patent applications can be classified into four groups:

Non-provisional, original provisional, reissue, and international PCT.

1. Non-provisional Patent Applications constitute the vast majority of U.S. patent applications. Often referred to as a “regular” or “formal” application, a non-provisional application is reviewed by a USPTO patent examiner. If it claims a patentable invention, it will ultimately mature into an issued patent.

Non-provisional applications can claim the benefit of the filing date of one or more earlier filed U.S. applications, as well as the date of a foreign patent application filed no more than one year before the non-provisional application’s filing date. A non-provisional application is usually published by the USPTO 18 months after its earliest claimed filing date.

2. Provisional Patent Applications also may be filed with the USPTO. This type of application is used to establish a priority of invention; in other words, to secure a filing date for a given disclosure of the invention. By operation of law, the provisional patent application becomes automatically abandoned on the first anniversary of its filing date, and is never itself either examined or published by the USPTO. To benefit from the filing of a provisional patent application, a non-provisional patent application must be filed no more than 12 months after the provisional patent application’s filing date, and must make an explicit reference to the provisional patent application filed earlier. As long as a non-provisional patent application is properly filed within the 12-month period, the provisional patent application filing date is used as the later application’s effective filing date. That date, however, only applies to inventions adequately described in the provisional patent application.

A word of caution here: To properly serve as a priority document, a provisional patent application must include a written description, perhaps featuring drawings, that enables a person of ordinary skill in the art to understand and practice the invention. The “best mode” requirement also applies and refers to the inventor’s obligation to describe the best way he or she knows for practicing or carrying out the invention. Any additional or new subject matter presented in the later filed non-provisional patent application will not be entitled to the provisional patent application’s earlier filing date.

3. Reissue Patent Applications are patent applications filed to correct a “defect” in an issued patent. A “narrowing” reissue seeks to narrow the scope of one or more claims, such as claiming more than the patentee (patent owner) had a right to claim. It can be filed at any time prior to the expiration of the patent’s term. A “broadening” reissue seeking to expand the claims coverage must be filed with the USPTO no more than 2 years from the date upon which the patent was originally issued.

4. International PCT Patent Applications are patent applications filed under the Patent Cooperation Treaty (PCT). In a PCT application, the applicant designates one or more of the many PCT member countries, encompassing virtually all of the industrialized world, to preserve the option to later file the PCT application in any designated country. The PCT patent application can be filed in any one of the many national patent offices, subject to rules relating to the applicant’s nationality and residency.

The PCT application must be filed no later than the one-year anniversary of the earliest related patent application. If the PCT application designates the United States, then it is deemed by law to be an application for a patent filed in the United States as of its international filing date. The differences between the processing of international PCT patent applications and U.S. non-provisional patent applications is extensive and beyond the scope of this book. It should be noted, however, that an international PCT patent applicant must take further action in the United States and other countries in order to obtain patents in those countries. Generally, those actions must be taken no later than 30 or 31 months from the earliest claimed priority date, depending on the country.

To find out more please access our IP Primer page.