Research On The Application Of The Estoppel Principle In Patent Infringement Litigation

At present,the principle of estoppel,although only at the level of judicial interpretation about its provitions in China’s patent system,has gradually become an important principle of patent infringement judgment in judicial practice.However,it is because of the lack of clear regulations and more detailed judicial interpretations and case guidance that different courts apply different standards in China.Cao Guilan,Hu Meiling,etc.v.Chongqing Lifan Automobile Sales Co.,Ltd.,etc.case of infringement of invention patent rights(the following referred to as Lifan case)has also experienced a wave of twists and turns.It can be imagined that the principle of estoppel has many needs to be clarified and improved in patent infringement litigation.Although the theoretical circles have discussed this principle early,they mainly discuss the relationship between the principle of estoppel and the principle of equivalence.Therefore,there is a lack of in-depth study of the principle of estoppel,which leads to difficulties in the independent application of the estoppel principle.The thesis takes the Lifan case as the beginning,analyzes the problem through the way of problem introduction,and finally solves the problem of the application of the estoppel principle..In addition to the introduction and conclusion,this thesis contains the following four parts:The first part briefly introduces the trial situation of the Lifan case and the controversial focus of the case trial,which leads to the issue of the recognition of the abandonment standard and the review of the restriction applicable conditions in the patent infringement lawsuit of the estoppel principle.The second part analyzes the application of the principle of estoppel in patent infringement litigation,first clarifies the disputes that have always existed in the application of the principle of estoppel,that is,the relationship between the estoppel principle and the principle of equivalence,and then analyzes the domestic abandonment standard on this basis that it was mainly divided into two aspects: modification and opinion statement,and finally examined the case of the review of the abandonment standard in the US patent infringement lawsuit..The third part analyzes the application of the prohibition of estoppel principle in patent infringement litigation.The author proposes that pure interpretation and decorative modification will not lead to the narrowing of the scope of protection.Therefore,it is necessary to distinguish between restrictive interpretation and pure interpretation,and examine and confirm decorative modification.At the same time,the explicit negation of the provisions of the judicial interpretation to limit the application of the principle of estoppel,it is also necessary to clarify its identificationThe fourth part discusses the application of the estoppel principle in patent infringement litigation and the application of restrictions.First of all,to accurately locate the judicial function of the principle of estoppel,the principle of estoppel is not only a means of defending the principle of equality,but also an interpretation of the scope of protection of patent rights,and a means of balancing interests between the patentee and the public.Secondly,to interpret the provisions of the judicial interpretation on the principle of estoppel,the provisions of judicial interpretation form a countervailing effect on the application of the principle of estoppel to a certain extent.Finally,the author proposes to refer to the abandonment criteria established in the US festo case,and at the same time,to explicit conditions of investigation of the estoppel principle restriction appliance,and it is necessary to objectively review the nature of the statement and modification,as well as the requirements of the explicit negation.The fifth part responds to the controversial focus of the Lifan case,and sorts out the difficulty of reviewing abandoned standard in the Lifan case.Based on the abovementioned parts,it examines whether the technical solutions implemented by the defendant in this case belong to Jiang’s abandoned protected range from the two aspects of revision and opinion statement.From the perspective of balance of interests,The patentee fully discloses his technical plan in order to obtain exclusive benefits for a certain period of time,and the privileged interests generated by the public based on a comprehensive review of the patent application process and invalidation procedures can be protected.Trust for the sake of out of context should not be protected.