Doctrine of Equivalents After Hilton Davis: A Comparative Law Analysis

This Article will address a number of major topics. First, it discusses the Federal Circuit\u27s renewed interest in Graver Tank and the merger of the infringement test with the patentability test established by the Supreme Court in Graham v. John Deere Co. Then, this Article responds to the dissenting judges in Hilton Davis who emphasized the danger of uncertainty that stems from the in-principle application of the doctrine of equivalents. This response explains that the application of the doctrine does not increase the uncertainty in determining infringement but, rather, encourages clear, definitive claim drafting. It then examines the relationship between the uncertainty in determining infringement and the patent laws of foreign jurisdictions, and it demonstrates that the application of the doctrine proffered by the Hilton Davis majority will increase the legal certainty of infringement determinations. This Article also contends that the test for infringement under the doctrine of equivalents should parallel the standard for nonobviousness. Whether there is a substantial difference between a claimed invention and an accused device or process is a question of law to be determined by judges on the basis of a jury\u27s factual findings. To enable juries to make reasonable decisions, more detailed jury instructions than those given in Hilton Davis are necessary. In conclusion, this Article proposes a method for restructuring U.S. patent claim interpretation theory under a central claiming principle