Despite differences in patent law jurisprudence in Germany, the United Kingdom and the United States, the fundamental principles underlying each system serve the same basic purpose: to encourage technological innovation and dissemination of knowledge. In granting exclusive patent rights, it is important that the scope of patent protection not be so broad as to remove existing knowledge from the public domain. The scope of protection should strike a balance between granting adequate patent rights while preserving the public's ownership in the public domain or the prior art. To encourage innovation patentees must attain significant exclusive rights, while potential infringers receive sufficient notice of a patent's scope. To realize patent system goals, the scale measuring adequate patent protection should not be so heavy as to outweigh the public's right to know the scope of a patentee's rights. Several issues in patent law jurisprudence in the aforementioned countries reveal the tension between adequate protection and the rights of the public. Such doctrines include: a) the on-sale bar, b) public use, c) obviousness, and d) the doctrine of equivalents. While all four issues are illustrative, this Article focuses on the doctrine of equivalents[...] In Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., the United States Court of Appeals for the Federal Circuit (Federal Circuit) unraveled centuries of precedent. The court virtually eliminated the doctrine of equivalents as a method of finding patent infringement in routine and conventional situations. Prior to Festo, the doctrine of equivalents was a viable theory for determining patent infringement. After Festo, the policies underlying the doctrine of equivalents have taken a back seat to bright line rules with little substantive basis[...] Part I of this article is a general overview of the history of both the doctrine of equivalents and prosecution history estoppel; Part II discusses Festo and what the case holds; Part III discusses where Festo conflicts with Supreme Court precedent; Part IV articulates the additional factors that encompass public policy concerns regarding scope restraint as the basis for evaluating equivalents; Part V presents and analyzes cases utilizing the Formstein test in their rationales; Part VI explores tangential issues prompted by the Festo decision; and Part VII sets forth the conclusions reached from the analysis.
Katherine E. White,
Festo: A Case Contravening the Convergence of Doctrine of Equivalents Jurisprudence in Germany, the United Kingdom, and the United States,
Mich. Telecomm. & Tech. L. Rev.
Available at: https://repository.law.umich.edu/mttlr/vol8/iss1/1