How does secret use affect public use determinations in patent law?

Secret use of an invention can still constitute public use under certain circumstances, potentially affecting patentability. The MPEP 2133.03(a) states:

“Secret use of an invention by the inventor or his agents for his own profit or advantage prior to the critical date is a bar to a patent […] even though the use may not be a ‘public use’ in the literal sense of the term.”

This means that even if an invention is used in secret, if it’s for commercial purposes or profit, it may be considered a public use that could bar patentability. The key factor is whether the use is for the inventor’s commercial benefit rather than for experimentation.

To learn more:

• secret use
• public use
• commercial use
• patent bar