Protecting IP with “First Impression” Court DecisionJuly 16, 2024

June 3, 1988 decision of “first impression” obtained by Ed Sease at the specialized U.S. Court of Appeals for the Federal Circuit (CAFC) in Washington, D.C. It was the first time the CAFC had directly dealt with the issue.

An employee assigned all patent rights in his invention to employer Diamond Scientific. The employee left the company and marketed a product Diamond alleged infringed the patent. The employee answered the lawsuit by challenging the validity of the patent. Called “assignor estoppel”, the CAFC held it would be unfair for an inventor to claim a patentable invention before he assigned it, and then claim the invention was not patentable after. This was an important safeguard for companies or entities that receive assignments and patents.