Legal Definitions - public-use bar

A public-use bar is a legal term that refers to a rule that prevents an inventor from obtaining a patent for an invention that has been publicly used or sold in the United States for more than one year before the application date. This rule is stated in 35 USCA § 102(b).

For example, if an inventor publicly demonstrates their invention at a trade show or sells it to the public, they may be barred from obtaining a patent for that invention if they wait too long to file their patent application.

The public-use bar applies to any public use, commercial use, sale, or offer of sale of the invention. It also applies to private transfers made without a pledge of secrecy. This means that if an inventor shows their invention to a friend without requiring them to keep it a secret, that could trigger the public-use bar.

The purpose of the public-use bar is to encourage inventors to promptly file their patent applications and to prevent them from delaying the process while they test the market or refine their invention.