On The Application Of The Principle Of Equivalent In Patent Infringement Determination And Their Limitations

Doctrine of Equivalents, which is widely applied in casesregarding copyright infringement, is a general criterion for thedetermination of alleged Infringement. Established and developedin the judicial practice, Doctrine of Equivalents was firstly created tooffset the insufficient of literal doctrine and to avoid the infringers’attempts to evade punishment. However, as a beneficialsupplement for the Principle of Comprehensive Coverage, Doctrineof Equivalents, which aims to protect the patentee more adequatelyand comprehensively, was not an ordinary rule to determinecopyright infringement. But, overemphasizing the protection of thepatent right and neglecting the balance of interests between thepatentee and the public, a unprincipled range for the application ofDoctrine of Equivalents may be triggered, then by so some legalbehaviors may be misjudged as infringements, and consequentlydamage the public’s interest and affect implementing the purposeof the Patent Law.For this reason, Principle of Estoppels and Principle of Prior Art were established to restraint the Doctrine of Equivalents, and bymaking the patent system more reasonable, the patentee’s interestcan be defended as well as the public’s interest can be protected.This paper will set forth with the Doctrine of Equivalents from manyperspectives such as the history, the application and the limitation,and then the author will bring up some viewpoints and suggestionsconcerning these issues. Intention is that hopefully will Doctrine ofEquivalents be well developed in China.