On The Doctrine Of Equivalents In Patent Infringement Litigation Applicable

The doctrine of equivalents was established in America about two hundred years ago. Under the influence of America, many developed countries, such as England, Germany and Japan have adopted the doctrine of equivalents in the patent infringement action. So has the World Intellectual Property Organization. So, the doctrine of equivalents has become an international principle on judging the infringement of patent.In our China, some judicial interpretations have given comparatively explicit provisions on the application of the doctrine of equivalents, but in these documents still exist many defects which need clarifying and perfecting.This paper consists of five parts:Part Ⅰ: The author mainly introduces the basic theory of the doctrine of equivalents, and studies its historical process in America and its economical and social reasons. On the basis of analysis of the essential reasons why finally England and Germany both choose the doctrine of equivalents, the author proved that the scope of patent should be adjusted on the basis of the claim of rights.Part Ⅱ: This Part discusses on the jurisprudence basis of the doctrine of equivalents — the theory of balancing interests, and points out that the system of patent should be adapted to its social background, i.e. the design of the system of patent should pay attention to every interested party , and keep the balance of interests of patent holders, the society and the nation in order to realize its greatest value pursuit according to the characteristics of the times and the country's general technical level.Part Ⅲ: This part contains four divisions: at first, through the investigation of the vicissitudes in the system of patent, the author believes that the essential reason for the vicissitudes is the consideration of national economic benefits. Besides, the author argues that the starting point and goal of our country's system of patent is also increasingeconomic benefits. In addition, considering the fact that the patent market has been mostly monopolized by foreign enterprises, the author indicates that in China, the intensified protection for patented technology is mainly the protection for foreign patented technology in essence, which may hinder the development of domestic technology. Finally, according to the historical experience of international economical development, if the level of domestic technology is low, the protection for patented technology should be correspondingly low. Chinese economy and technology is far lower than the level required by TRlPs, so implementing the intensified protection for patent according to TRIPs, will inevitably become an obstacle of Chinese technology innovation. Consequently, the author comes to a conclusion: when applying the doctrine of equivalents, the protection for patent holders should not been intensified excessively.Part Ⅳ: This part demonstrates that the doctrine of equivalents should be applied in strict criteria. Directed by this thought, the author discusses about that problem from three perspectives: the first is the methods of judging the infringement of equivalents; the second is the premise of applying the doctrine of equivalents — defining the scope of patent protection; the last one is the subjects, objects, scope and time criterion of applying the doctrine of equivalents. Finally, the author points out the defects of the current laws, and put forward his suggestion.Part V: the author discusses about how to restrict the doctrine of equivalents by applying file wrapper estoppel and so on , which should be regarded as not only the methods of counterplea, but also the constructional conditions, so that the court can apply the foresaid principles actively , ensuring the balance of the interests of patent holders, the society and the nation.