Meaning
The actual employment or sale of a technology or design in the public sphere before its formal patent application. This prior public use constitutes a bar to patentability because the invention is no longer considered novel once it has been disclosed to an unrestricted audience. In the Chinese legal context, this includes products displayed at trade fairs or items sold on e-commerce platforms.
Verification Process
Proving that a technology was in the public domain requires contemporaneous documentation such as sales contracts, shipping invoices or dated photographs. The prior public use must be substantiated with evidence that shows the technical features were accessible to others without a non-disclosure agreement.
Infringement Defense
A party accused of patent infringement can avoid liability by demonstrating that they were already using the technology before the patent was filed. This prior public use defense allows the existing manufacturer to continue their current operations despite the new patent. It does not invalidate the patent for everyone else, but it creates a specific right for the original user to remain in the market.
Boundary Condition
Experimental use in a controlled environment does not typically trigger this status. Any prior public use must involve an actual disclosure that allows a third party to understand the technical details of the invention.
