A Research On The Principle Of Prosecution History Estoppel And Its Application

Nowadays, some principles concerning patent trials have been introduced and applied in patent cases in our country, for example, the principle of prosecution history estoppel, the principle of equivalent and so on. The principle of equivalent has been applied widely in patent cases. On the contrary, due to its ambiguous definition and explanation in patent law, administrative regulations and legal explanations, some courts are at a loss to some extent when applying the principle of prosecution history estoppel in design infringement determination. However, just like the principle of equivalent, the principle of prosecution history estoppel plays a significant role in accurately defining patent rights of the patentee and constructing a dynamic balance between the patentee and the public interests. Therefore, it is both meaningful and necessary to carry out a research on the principle of prosecution history estoppel.The thesis begins with the application of the principle of prosecution history estoppel in Festo case in America. The complete bar rule established by CAFC is denied and the flexible bar rule is adopted. The position of American court will have a significant influence on courts and scholars in China.Firstly, the author analyses the definitions of estoppel, distinguishes the definitions of estoppel from several aspects, points out the topic of the research, that is, prosecution history estoppel, and then carries out a brief review of the development of the principle of prosecution history estoppel and gives an initial introduction of the relationship between the principle of prosecution history estoppel and the principle of equivalent. The thesis then discusses the application basis of the principle of prosecution history estoppel and analyses its justification when applying the principle of prosecution history estoppel. The author argues that either the revision of patent documents or the statement of one's views will result in the application of the principle of prosecution history estoppel. Meanwhile, both the principle of prosecution history estoppel and the principle of equivalent play their important roles, but there is not necessarily subordinate relationship between them or priority in their applications. Then the thesis discusses the conditions of applying the principle of prosecution history estoppel from the angles of invention patent, utility model patent and design patent respectively, from which we draw a conclusion that the principle of prosecution history estoppel is applicable in design infringement cases. In the following part we point out some problems concerning the application of the principle of prosecution history estoppel in patent infringement cases in China, propose constructive suggestions, and introduce and analyze briefly applying the principle of prosecution history estoppel in a domestic case about patent infringement, which is followed by a conclusion of the thesis.