The Festo decision was a threat to the US doctrine of equivalents, or DOE. This doctrine has been relied upon for years by patent owners to stop copycat products that use technology similar to their original. Basically, the doctrine says that if a product or process is not substantially different from the elements of a patented invention, it is considered to be infringing.
Festo Corporation is a robotics company in Long Island, New York. It challenged a Japanese rival, Shoketsu Kinzoku Koygo Kabushiki, alleging patent infringement. The federal court ruled that there was no infringement. Significantly, it added that Festo lost certain rights in its technology as soon as it narrowed its original claim for a patent.
Until the Festo case, elements of an invention stripped from a patent claim during amendment were still considered the property of the inventor under US law, even if they did not appear in the formal patent description. Very few US patent applications succeed without some degree of amendment, so the decision in November 2000 made inventors nervous. It threatened to render thousands of patents worthless.
However, the Supreme Court yesterday limited the scope of that decision in a unanimous ruling.
Justice Anthony Kennedy’s opinion, released yesterday, said that amending patent claims does not automatically strip patent-holders of equivalence protection. However, the opinion adds that amending a patent claim does create a presumption that the amendment was intended to narrow the claim. If that presumption is not rebutted, the protection of the equivalents doctrine will fall.
Kennedy explained that a patent owner could rebut the presumption by claiming that the amendment involved a feature that was “unforeseeable at the time of the application” or “for some other reason” could not be included in the original claim.
According to American Lawyer Media, US patent experts consider that the ruling puts new burdens on those applying for patents “to justify amendments in ways that won’t leave their claims vulnerable to attack.”
The journal quotes Gregory Castanias of US firm Jones Day Reavis & Pogue who points out that the Festo decision was “tweaked,” not reversed. Instead of an absolute ban on the doctrine of equivalents, there is now a presumption that “will be difficult to overcome, except perhaps in areas of technology where growth is fast and advancements not easily foreseen.”
As regards the circumstances of the original Festo dispute, the Federal Court has been ordered to reconsider the matter in light of its ruling.