On The Doctrine Of Equivalents In Patent Infringement

The basic purpose of the patent system is protection of the patentee's legal rights, encouragement of the invention creation,and on this foundation through the publishing patent technique project promote science technique progress and innovation.But,all kinds of the patent infringements is baffling the realization of the patent system,especially equivalent infringement.The doctrine of equivalent(DOE) that balancing the benefits between the patentee and public is established and gradually developed by American courts in its judicial practice.This doctrine have run about 150 years,under this doctrine the scope of patent protection is not only the scope that claims hold,but also the substantial identical elements to the claims.Statute law does not contain DOE,that established from the case law through a series of patent infringement cases.American cases discuss the related issues about DOE profoundly,that deserve the reference for Chinese judge and scholar,investigate the DOE given legislation and judicature guide in theory,broaden study field toward intellectual property,mean a lot for patent law and intellectual property law.The dissertation firstly introduces how DOE emerged and justification of DOE. In the following part,leading cases regarding DOE in different period are selected and summarized,from where the attitude American courts toward DOE can be found in that corresponding period.The biggest problem and challenge,from judicial practice in America,is how to conquer the randomness of DOE.Patent system must balance between monopoly right of Patentee and notice function toward public.The doctrine of equivalents enhances the strength of a patent and fosters the protective function bygiving the courts the flexibility to expand the patent's scope beyond that of its literal terms.However,broad application of the doctrine of equivalents can diminish the notice function of patents by preventing the public from being able to determine the scope of a patent ex ante.For this reason,a series of criteria of and bars to DOE have been formulated by American courts in its judicial practice to make a reasonable result by applying DOE.These criteria and restrictions are elaborated in the present dissertation.Lastly,the domestic situation of legislation and justice relating to DOE is presented,and some suggestions are made to perfect the application of DOE in the future in China.