In order to judge whether an accused product infringes a invention patented or not, the claim scope of the invention need to be interpreted to decide the protection scope of the invention under a definite rule considering an equilibrium the interested party. To define clearly the scope of protection of the patented invention, we must determine the of scope of the claims. Actually, interpretation methods and legal theories which have been developed in the United States and Japan have an influence on our patent process concerning the interpretation of the claims. This thesis explores the history and principles of the interpretation of the claims, and studies on the application of the Doctrine of Equivalents on judging a patent infringement. European Patent Treaty and Patent Law Treaty suggest to apply the function/ way/ result test and obviousness of interchangeability as the equivalent criteria for infringement test.
This means that the doctrine of equivalent for finding infringement is a common standard and require for our court to accept the international trends. In this regard, judicial base needs to be established for applying the Doctrine of Equivalents in Korean Patent Law. Furthermore, the scope for application of the Doctrine of Equivalents should be defined through tangible discussions suitable for Korean Patent Law and the Korean technological environment.