The Application Of The Doctrine Of Estoppel In Judgement Of Patent Infrigement

The doctrine of estoppel is one of the important doctrines injudgment of patent infringement. The courts always actively acknowledgeand apply the doctrine of estoppel to judge lots of patent infringementcases. However, due to lack of the explicit legal provisions, the courtstypically determine whether and how to apply the doctrine of estoppeldepending on the judge’s power of discretion, which usually arouses a lotof controversy in the judgment practice.This paper chiefly introduces the summary and application of thedoctrine of estoppel, and specifically analyses the application of thedoctrine of estoppel in judgment of patent infringement in connectionwith three typical patent infringement cases in China. In Zhongyu vs.Jiuying case, the paper discusses that the doctrine of estoppel may beapplied to the technical solution self-abandoned by the amendment of thepatentee. In Lichanggao vs. Huarunwanjia case, the paper discusses thatthe doctrine of estoppel may be applied to the technical solution excludedby the patentee when filing the patent application. In Nuoboer vs. Jiguang case, the paper discusses that the doctrine of estoppel may be applied tothe technical solution abandoned by the observations stated by thepatentee in the patent invalidation process.Finally, with reference to the application of the doctrine of estoppelin judgment of patent infringement in USA and Japan, the paper proposessome suggestions for the application of the doctrine of estoppel caused bythe amendment in the patent application process, the amendment in thepatent invalidation process and the observation stated by the patentee inour country.In patent infringement cases, the courts should also consider thebalance between individual interests and the public interest. The paperprovides some materials aforementioned, expecting to propose somefeasible solutions in the application of the doctrine of estoppel in the legalpractice.