The Applying And Limit Of Doctrine Of Equivalents In The Affirmation Of Patent Infringement

Doctrine of Equivalents is the major and knotty problem in the affirmation of patent infringement. The first chapter of this thesis recites the concept of the Doctrine of Equivalents, its history and primary theories in some countries; the second chapter analyses the standard of the Doctrine of Equivalents in different period in China, and express author's opinions for some difficult questions in applying the Doctrine of Equivalents in the affirmation of patent infringement in China; the third chapter expound the two limits of applying Doctrine of Equivalents: File Wrapper Estoppel and Existing Art; the fourth chapter discuss the ways for improving the Doctrine of Equivalents in Chinese judgment practices.The Doctrine of Equivalents expands the patent protection to the equal field, which is for maximal benefit between patent protection validity and patent scope specification. The Doctrine of Equivalents was founded and developed through determining infringement of patent in American courts. From the date of its emergence, the Doctrine of Equivalents underwent whole equivalent and all elements rule. The American Doctrine of Equivalents now is applied in justice practice of many countries.After the China judicial interpretation in 2001 defined the Doctrine of Equivalents, some bylaws just for the reference only was published by the district courts. But the applying standard of the Doctrine of Equivalents was still different in many items.The article expresses author's opinions for the time of the Equivalent and some difficult points in applying the Doctrine of Equivalents. The judgment for Equivalent should base on the infringement date as the time of Equivalents. In the justice practices, technology appraisal result should be only used for judge's reference, could not alternate him to judge the cases.File Wrapper Estoppel and Existing Art are two doctrines for the limits of Doctrines of Equivalents.File Wrapper Estoppel rules that prohibit patentee including back the technical features that have been excluded to the scope of patent protection by the patentee statements during the patent application process. Now there is not any formal rule for File Wrapper Estoppel in China.There are two viewpoints for Existing Art, one is Free Existing Art, another one that author agree is including all prior art before filing date (or priority date). Existing Art could apply both in infringement judgments for equivalent and same.The laws for applying Doctrine of Equivalents are laggard in China and there is a lot of blankness in judgment standard and limit conditions. We should develop China law system and justice system to make Doctrine of Equivalents benefit the public more and more in the future.