The Doctrine of Equivalents and Interchangeability in the United States, Taiwan and China

Abstract

The United States, Taiwan and China have similar systems for determining patent infringement under the doctrine of equivalents. The courts in these countries apply the test of interchangeability in finding infringement under the doctrine of equivalents. However, the courts in the United States, Taiwan and China evaluate interchangeability in different ways. In the United States, the interchangeability is one important factor for determining equivalent infringement in addition to the function, way and result factors in the triple identity test. Nevertheless, the court does not necessarily have to consider interchangeability and can’t rely only on the interchangeability factor to find equivalent infringement. In Taiwan, the triple identity test is a comprehensive test for determining equivalent infringement. Although interchangeability is not provided in the Guideline for Patent Infringement Analysis, some decisions by Taiwan’s Supreme Court treat the interchangeability as an independent and comprehensive test for finding equivalent infringement. In China, neither the SPC Provisions nor the SPC Interpretation provides interchangeability, but the Supreme People’s Court considered interchangeability in some of its decisions. The Court assessed the interchangeability by determining whether one skilled in the art could contemplate without creative work, followed the standard in the SPC Provisions and the SPC Interpretation, and treated the “creative work” as an necessary factor in addition to the function, way and result factors in the triple identity test for determining the equivalent infringement.