Legal Definitions - public-use bar

The public-use bar is a rule in patent law that prevents an inventor from obtaining a patent for an invention if it was publicly used or sold in the United States more than one year before the inventor filed their patent application. This rule encourages inventors to apply for patents promptly and prevents them from monopolizing an invention that has already been made available to the public or commercialized for an extended period.

Essentially, if an invention has been used publicly, offered for sale, or sold commercially for over a year before the patent application date, it is generally considered part of the "prior art" and cannot be patented. This includes any public demonstration, commercial use, or even a private transfer of the invention without a clear agreement of secrecy.

Here are some examples to illustrate the public-use bar:

• Example 1: Public Demonstration

  An inventor, Maria, develops a new type of self-watering planter. To gather feedback and generate interest, she sets up a booth at a large public home and garden show in April 2022, where she demonstrates the planter's features, allows attendees to interact with it, and openly discusses its design and functionality with hundreds of people. She does not ask anyone to sign a confidentiality agreement. If Maria waits until June 2023 to file her patent application for the planter, her invention would likely be subject to the public-use bar. Her public demonstration and use of the invention at the trade show in April 2022 occurred more than one year before her application date, making it unpatentable.

• Example 2: Commercial Sale

  David invents a unique device that attaches to a bicycle to generate electricity for charging small electronics. To test the market and begin earning revenue, he starts selling a limited number of these devices directly to cyclists through an online store he created in January 2021. He sells several dozen units over the next few months. If David then decides to file a patent application for his bicycle charger in March 2022, the public-use bar would likely apply. His commercial sales and use of the invention in January 2021 occurred more than one year before his patent application, preventing him from obtaining a patent.

• Example 3: Offer for Sale Without Secrecy

  A software engineer, Emily, develops an innovative algorithm for optimizing energy consumption in smart homes. In July 2020, she approaches several major utility companies, providing detailed presentations of her software and offering to license the technology to them. She shares the full technical specifications and even provides a working demo for one company to evaluate for a month, all without requiring any non-disclosure agreements. If Emily decides to file a patent application for her algorithm in August 2021, the public-use bar could prevent her from obtaining the patent. Her open offers to license and the trial use of the software in July 2020 constitute a public offer for sale and use more than a year before her application.