The doctrine applies where an element performs substantially the same function in substantially the same way to achieve substantially the same result. It is applied limitation by limitation rather than to the invention as a whole.
Prosecution history estoppel and the all-elements rule limit it.
Alternative Names:
Equivalents|DOE
Why it Matters?
Prosecution history estoppel bars equivalents for limitations narrowed during prosecution for reasons related to patentability, which forecloses the doctrine for most amended claims and is the primary defense. The all-elements rule separately prevents equivalents from vitiating a claim limitation entirely. Disclosure-dedication also bars equivalents covering subject matter disclosed but not claimed, which is an underused defense.
Frequently Confused with
Related terms
Frequently asked questions
What is the primary defense?
What is the disclosure-dedication rule?
