The Doctrine Of Equivalent In Judgment Of Patent Infringement

The Doctrine of Equivalent is a balancer, which balances the relationship of interests between patentee and the public.The Doctrine of Equivalent is the indispensable in judging a patent infringement. Despite the most important role of the Doctrine of Equivalent, it is not easy to apply it in justice practice, because of its own characteristic of uncertainty and subjectivity.In America, the Doctrine of Equivalent has been developing about two hundred years. The establishment of the Court of Appeal of Federal Circuit (CAFC) acts as a direct stimulus to the development of the Doctrine of Equivalent. The American courts have built a set of rules regarding the Doctrine of Equivalent by summarized a series cases in its judicial practice, including the Function-Way-Result Test, All-Elements Rule Prosecution History Estoppel, the State of Prior Art and the Dedication rule.As is mentioned above, though the Doctrine of Equivalent plays a very important role in judging a patent infringement, but there are no provisions on our patent law. However, the Doctrine of Equivalent is admitted by Chinese courts in judicial practice based on some basic principles of Civil Law such as fairness and honesty and credibility. The result is that confusion arises in judicial practice.The goal of the dissertation is to table a proposal by studying the application of the Doctrine of Equivalent in both American courts and Chinese courts, and then build up a model of judgment in patent infringement. In order to reach the goal, the dissertation firstly introduces what the Doctrine of Equivalent is. And then, in the following part, the dissertation introduces how the Doctrine of Equivalent emerged and application and developed in America by selecting several cases judged by American Supreme Court regarding the Doctrine of Equivalent in different period. Thirdly, the domestic situation of legislation and justice relating to the Doctrine of Equivalent is presented. Fourthly, some suggestions are made to perfect the application of the Doctrine of Equivalent in the future in China based on comparing the application of the Doctrine of Equivalent in American judicial practice with the application in Chinese Courts. Lastly, a model is built for the purpose of reducing the uncertainty and subjectivity in judging a patent infringement.