In order to be eligible for a patent, it is very important to obtain the earliest priority date possible. By being the “first in line,” you improve your chances of obtaining a patent over someone else.
However, filing a patent application is a costly and complex process. It requires drawings, a specification, claims, and payment of a filing fee, as well as maintenance fees after the patent has been issued. The patent prosecution process often takes years, and there is no guarantee that an application will lead to a patent, as many applications are rejected the first time, often on prior art grounds.
Additionally, many inventors are not completely sure if their invention merits the time and expense of prosecuting a patent application. It occurs to me that this is where a provisional application might come in handy.
A provisional application requires only a specification, drawings, and a cover sheet indicating that the application is provisional. A provisional application is not examined by the PTO; it is akin to making a reservation at a restaurant or hotel in that it is valid for a limited time.
After filing a provisional application, you have up to one year to either file a non-provisional patent application, or simply let the provisional application expire. Once the provisional application has expired, it cannot be revived. If an inventor files a non-provisional application prior to the expiration date of the provisional application, then the date the provisional was filed becomes the priority date of the non-provisional application.
A provisional application does not lead to a patent; it only buys an applicant up to 12 months of additional time to conduct further research, testing or marketing of the product and decide whether or not to file a regular (non-provisional) application.
Provisional applications may be converted to non-provisional applications, however, this is not always advised because the priority date becomes the date when the provisional application was converted, not when it was first filed. For this reason it may be better to file a non-provisional application before the 12-month deadline passes.
What do you think about the use of provisional patents? Are they worthwhile to do? If so, when?