How to Invent and Protect Your Invention: A Guide to Patents for Scientists and Engineers

6.2 THE PROVISIONAL PATENT APPLICATION

In 1995, in order to harmonize U.S. patent procedures with international (mainly European and Japanese) practices, a new rule was added to the Patent Law: the provisional patent application to lock in the filing date.

First a warning: The term “provisional patent application” is a misnomer if there ever was one. The provisional application is by no means an “application” but an interim document that establishes the inventor's priority to invention, provided that a regular patent application is filed within one year. The provisional application is not examined and expires after one year; in other words, the PTO doesn't do anything with the provisional application except keep it on file. The provisional patent application is and remains secret. It is not published like a regular patent application, which is published 18 months after it is filed with the PTO. The actual document is rather simple; it describes the invention clearly and fully, but no claims, abstract, summary, or background will be needed!. It must be sufficiently detailed to enable technical people to repeat and use the invention and must include the best mode. The best mode is the best experimental condition the inventor has found to carry out the invention at the time the application is filed.

A provisional patent application provides important advantages to the inventor. The greatest advantage is that it proves completion of invention, so that after filing, the inventor is ...