A provisional patent application is a special type of application for patent available in the US, Australia, India and some European countries such as the UK. A provisional application can be a useful tool for applicants to manipulate certain patenting strategies for their inventions, provided that it has been used in an appropriate way. US provisional patent applications, which have been widely used since its introduction in 1995, will be taken to discuss some basic concepts of a provisional patent application.
In essence, a provisional patent application, which is used as a temporary and transitional means, will not directly result in issue as a patent. Rather, a provisional application establishes an effective filing date for its subsequent non-provisional patent application. In this way, if the applicant is ready to obtain a patent, a corresponding non-provisional application can be filed within 12 months pendency period of the provisional application, claiming the priority of the provisional application. In addition, the provisional application for patent is well recognized internationally by major countries all over the world so its benefit can also be claimed in corresponding foreign or PCT patent applications within the pendency period for 12 months.
Compared with a non-provisional application, a provisional application generally incurs lower application costs and has lower requirements. Particularly, a provisional application does not require any claims, abstract, oath, declaration, information disclosure statement or other format requirements of application documents. Instead, only a brief written description to explain the essence of the invention shall be sufficient, and if necessary, drawings may be provided for illustrative purpose. No examination will be conducted for the provisional application at all, and publication of the provisional application will not happen. The patent term of the corresponding non-provisional application is counted from a filing date of the subsequent non-provisional patent application, and the filing date of the earlier provisional application is not counted as a part of the 20-year patent term of the patent, which brings about extra 1 year of protection period for the invention. Besides, the applicant is allowed to use the term "patent pending" on the invention which is described to fall within the scope of description of the provisional patent application as submitted.
The reduced filing threshold of a provisional patent application offers a number of significant advantages, including low application costs, simple application documents and short preparation time. Therefore, provisional patent application filings are very useful for some circumstances where applicants may have to disclose their inventions, for example to reveal their inventions during commercial exhibitions, academic seminars or when raising funds from outside parties. Then there is a need for filing patent applications to establish a filing date (i.e. priority date) for their inventions within a definite date. At this juncture, very often, there is no sufficient time for the applicants to file a well prepared patent application before the appointed date of public disclosure. In certain circumstances, some applicants may need some time for business planning and evaluation of their inventions before they can decide to pursue a patent or not, whilst they want to secure an earlier filing date of patent application to ensure a priority right for their inventions in the first place. Yet in other situations, some applicants would like to keep improving their delicate inventions while they want the existing core technologies of the inventions to be protected. In the above-mentioned circumstances, a provisional patent application shall be the way to go, especially when the patent systems in the world are dominated by first to file doctrine.
In spite of the above, the reduced filing threshold of a provisional patent application sometimes leads to potential problems associated with non-provisional patent applications at later stage. Some applicants may consider that the written description prepared for the provisional application may be amended and replaced by a complete well-prepared description of the subsequent non-provisional application. That being said, the provisional patent application shall fulfill the requirement that the inventions must be disclosed in the provisional application in a complete and clear manner to an extent that the inventions can be reproduced, and the incomplete written description may be detrimental to the subsequent non-provisional application. This is because the originally filed insufficient disclosures may lead to less coverage of core technical features of the inventions or unfair generalization of the invention to encompass potential variations of the invention. Accordingly, when new matters or new variations, which are not supported by the provisional application, are added into the corresponding non-provisional application, these newly added matters or variations cannot enjoy the priority benefit for going beyond the scope of the provisional application. Worse still, these new matters or variations may have been disclosed to the public by the applicants during the pendency of the provisional application owing to business needs or academic activities. Consequently, the public disclosure of the invention per se becomes prior art against the novelty of these new matters, as a consequence, the non-provisional application is not granted a patent right.
In view of the above potential pitfalls, it is recommended to make the description as complete and clear as possible further in consideration of fair generalization of potential variations of the invention to guarantee the priority of core matters of the invention in a broad sense. A complete and clear disclosure of invention should be adequate for those skilled in the art to understand and therefore implement the invention. Furthermore, since there is no examination for the provisional application, the applicants may not realize if there are any deficiencies in the application documents until they are discovered in corresponding non-provisional application at later stage. Therefore, it is preferable to prepare a provisional application in the same way as a non-provisional application so as to avoid the problems of insufficient disclosure. In addition, urgent and reckless filing of provisional patent application should be avoided if possible for the above reasons.
We may say a provisional patent application is like a double-edged sword, and it is a powerful tool of patent strategy but only works when used properly. To be on the safe side, it is advisable to consult your patent attorneys about the suitable routes to obtain a patent.