One-year rule is a term relating to patent law. It is also known as one year grace period or on sale bar. The rule states that an inventor must file for patent protection within one year from introduction of an invention by publication to the public. The one year rule prevents an inventor from patent protection if the application is filed after the lapse of more than one year since the occurrence of any of the following:
1.any public use of an invention by an inventor, a sale of an invention, an offer of sale, or public use of an invention in the U.S;
2. any description of an invention by an inventor in a published document in any country.
Failure to file a patent application within the one-year period will result in the invention being passed onto public domain, where it will no longer be eligible for a patent.