A patent cannot be acquired for an invention that has been in public use for more than one year at the time of application.

Question

Quizplus · Accepted Answer

This is known as the one year grace period rule, and it is a requirement of patent law in the United States. If an invention has been in public use for more than one year prior to the filing of a patent application, it is considered to be in the public domain and cannot be patented.

A Patent Cannot Be Acquired for an Invention That Has