Prosecution Disclaimer

A concept related to Prosecution History Estoppel, but which limits literal claim construction (or Literal Infringement) rather than claim construction under the Doctrine of Equivalence. Prosecution disclaimer can arise where an inventor in the course of prosecuting a patent offers a definition of a claim term that narrows the scope of the claim. Prosecution history disclaimer is not as powerful a weapon in narrowing claim construction as prosecution history estoppel because there is customarily a presumption that claim terms carry their normal and ordinary meaning – it is thus most effective when a claim term is not a ‘term of art’ with respect to the relevant technology. Prosecution disclaimer is also applied more narrowly outside the US, for example in Europe.