A New Restriction on Equivalent DoctrineClaim Vitiation Doctrine

The patent vitiation doctrine has developed in the United States more than 20 years, which roots in all elements rule of equivalent infringement. The original intention of patent vitiation doctrine is to impose further restriction on the application of the equivalent doctrine, emphasizing the limitation role of claim elements. Through the analysis of several cases in the United States, the article introduces the origin, definition and function of the patent vitiation doctrine, and summarizes the application of patent vitiation doctrine. The doctrine is deficient of self-consistent and there is no uniform standard and logic in application. The application of patent vitiation doctrine lacks predictability. Its function is not to impose further restriction on the equivalent doctrine but to negate it completely. The transplantation of that doctrine will break the balance between the doctrine of literal infringement and equivalent infringement, affecting the stability of the patent system, making the patent infringement judgment just a literal infringement. Patent vitiation doctrine is neither in line with China’s national conditions, nor serving the Chinese patent system.