A Study Of The Doctrine Of Equivalents In Judging Patent Infringement

The primary purpose of the patent system is to protect the lawful rights of the patentee and to encourage the invention-creation and to advance the science through the publication of patent documents . According to the theory of"balancing of the interests", the most important function of the patent system is to keep the balance between the patentee and the social public interests. Equivalent principle has 200 years history, now it has been widely accepted by international. Its appearance makes the patent system more perfect.This article discussed the concept of equivalent principle, application condition, the decision criteria and the development of equivalent principle in our country starting from the evolution of the equivalent principle, and then put forward some thoughts and suggestions. The paper text had more than twenty thousand words which can be divided into five parts as follows:The first part introduced the necessity of the application of the equivalent principle and then draw into the concept and the significance on the theory of the equivalent principle starting from dicussing the protection scope of the patent. This part also describes the development and establishment of the equivalent principle on the clue of the development of the equivalent principle in America.The second part discussed the application scope and application conditions of the equivalent principle mainly starting from the judge criteria , judge time and the subject of the equivalent principle.The third part mainly discussed several special cases in the judge of the equivalent principle, including changed bad invention, circuitous invention . Because China's existing the application of the redundant designated principle , the redundant designated principle was discussed emphatically.The fourth part mainly discussed the limitation of the equivalent principle which was important to the correct use of equivalent principle and was especially important to the balance between the patentee and the social public interests.In the fifth part the author put forward some ideas about the application of the equivalent principle in china including system construction, legislation and the application of the equivalent principle.