The Research On Principle Of Estoppel In Judgment Of Patent Infringement

The judgment of Patent Infringement has been one of the hard issues in judicial practice, while there are still many controversial and urgent questions of theory in the principle of Estoppel, which is one of the key rules in Judgment of Patent Infringement. Although this principle has been adopted in judicial practice, it has not been established in legislation. Enriching the research in it could maturate the theory perspective, and guide both legislative and judicial practice in our country. Principle of Estoppel is rooted in the balance view of common law. it can also be taken as the extension of integrity law in the civil law system. It can be known from the deep research on the principle of Estoppel from jurisprudence perspective, that Prosecution history estoppels not only is a limitation to the equivalent principle, but also has its independent theory foundation and logical system.Based on a great amount of legislation cases adopting the principle of Estoppel, we can see that the principle of Estoppel is not only a tool to limit the equivalent principle, but also a tool to define the extent of patent protection.If the patentee revises the claim of right and application files during the process of patent application and patent checkup, or limit the range of right protection, we can deduce that he has given up the right range between the original rights and the revised rights. But if the patentee can prove that his intention excludes the range of principle of Estoppel raised by accused person, he can conquer his equivalent assumption. In other words, equivalent principle is applicable in principle of Estoppel under such circumstances.Principle of Estoppel is based on balancing the needs of both patentee and public interest, principle of good faith and Credibility of patent documents. Besides the right of defense, principle of Estoppel is brought about to define the range of patent protection.Because of imperfect of legislations, lack of experiences and closure of patent files, the court can't apply the principle of Estoppel freely in cases related to patent infringement.Therefore the revise of patent law is of great urgent to solve the more and more complicate controversy over patent infringement in judicial practice. The related department should keep a close contact with Chinese reality, learn lessons from the legislative and judicial experiences of other countries for selectively, revise the patent law in time and specify the principle of Estoppel as well as other related principles.