The Study of Determination of Infringement under the Doctrine of Equivalents: From the Clarification of the Reflection of the All Elements Rule

The Doctrine of Equivalents (DOE), a common law creation that allows a court to expand patent scope beyond the rights literally claimed in the patent, might be the most controversial doctrine in patent law despite nearly two hundred years of development. There is without doubt that the DOE, when applied broadly, conflicts with the definitional and public notice function of the statutory claiming requirement. To avoid this conflict, the court adopted the rule that the DOE must be applied to individual claim elements rather than to the invention as a whole. Recent decisions from the Intellectual Property Court (IP court) and the Supreme Court, however, appear to be in conflict. In one of the most controversial court cases concerning an eye massage device, despite the IP Court has continued to use the ""element by element"" approach, the Supreme Court clearly stated that the Doctrine of Equivalents should be applied on an ""as a whole"" basis. Are these two equivalency tests in conflict or in harmony with each other? The issue is about whether we should apply the All Elements Rule or not. Although the need for the DOE is recognized in developed patent systems, the parameters of the doctrine and its appropriate application are still widely debated. This article will compare and contrast the doctrines applied in the U.S. and Germany. Each of these jurisdictions balances the interests between the patentee and the public differently, and each protects the patentee from non-literal infringement in a slightly distinct manner. Facially, each jurisdiction''s implementation of the doctrine of equivalents appears distinct, but closer comparative analysis reveals striking similarities between the application of these doctrines. This Article based on the fair and adequate protection of patent, tries to suggest an optimal legal model for application of the DOE, through the comparative approach. Part II of the article reviews the legal frameworks for determining the protection scope of the patent in the U.S, German and Taiwan. Part III of the article examines the DOE used in the U.S. and Germany including the applications of the All Elements Rule in the U.S. Part IV of the article tries to provide an adequate model for application of the DOE in Taiwan, through clarifying the policy behind the DOE with the patent policy and theory. The Article finishes with a brief conclusion.