Patent Infringement Apply The Doctrine Of Equivalents

The doctrine of equivalents, as an important principle to determine scope of patentprotection was founded two hundred years ago in the United States. Because thedoctrine of equivalents is not expressly provided in patent law, combined with thecomplexity of the doctrine of equivalents connotations, the use of the doctrine ofequivalents to determine patent infringement is difficult both in theory and in practice.In addition, the doctrine of equivalents gives judges a lot of discretion in applying thelaw which results in the application standard not uniform, the applicable rules not clear.As a result, the identification of patent infringement is difficult. This paper attempts tostudy doctrine of equivalents of patent infringement, which includes tracing thedevelopment history of doctrine of equivalents, clarifying patent infringement byequivalents. Through three cases, an accurate substance of the doctrine of equivalents isachieved, problems in judicial are provided, the applicable conditions and limitationsare presented. The article deepens our understanding of patent infringement doctrine ofequivalents and improves judicial efficiency of patent infringement cases.There are four parts in the article. The first part is overview of patent infringementof the doctrine of equivalents which defines the concept, the value and the legal basis ofthe doctrine of equivalents. The second part compares foreign legislation and practice ofthe doctrine of equivalents which introduces the generation、 development andapplication of the doctrine of equivalents of the United States、Germany and Japan.Through three cases, the third part discusses the application problems of the doctrine ofequivalents. In the last part, the article proposes an idea for better application of patentinfringement for the doctrine of equivalents.