Merging Civil and Common Law Traditions in the Patent Validity Challenge System: Japanese Experiences

Abstract

This paper compares patent validity challenge systems in Japan and the United States. Japanese courts long followed German tradition of a bifurcation system where accused infringers could challenge the patent validity only through the invalidation proceeding at the Japan Patent Office. Japanese Patent Law was recently revised to adopt a double track system where accused infringers can challenge the validity both in court and at the Japan Patent Office for facilitating a simple and quick disposal of patent disputes. The new system resulted in unexpected problems because of possible conflicting decisions in patent validity from different authorities. In contrast, the United States has been immune to these problems although it has used a double track system since 1980. This paper examines aspects of U.S. double track system that prevent conflicting validity decisions from the United States Patent and Trademark Office and courts and proposes to adopt these aspects in Japanese double track system.