Washington Law Review


Qing Lin


In patent law, the doctrine of equivalents allows courts to find infringement if one makes or uses a device or process without substantial change from a patented invention. A test that clearly defines the appropriate scope of patent protection is crucial to development in various industries, especially in biotechnology, an industry that requires significant long-term investment. However, the most commonly applied test for determining equivalents is vague and fails to provide practical guidance. The "all elements" limitation to the test causes additional confusion. A more appropriate test for defining the scope of patent protection would be the "nonobviousness test," a test similar to the nonobviousness requirement when inventors first apply for patents. The proposed test would benefit from a rich body of case law on the nonobviousness requirement for obtaining patents, would evaluate inventions as a whole, and would provide appropriate protection to patent owners. This Comment examines the recent development of the doctrine of equivalents, analyzes the problems with the current test that courts use to apply the doctrine, and urges courts to adopt the nonobviousness test to resolve patent infringement cases.

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