EQUIVALENT INFRINGEMENT
'Doctrine of Equivalents'
- Substantially same function
- Insubstantial differences
- Elements in an accused product that are “substantially equivalent” and still be ‘present’
- If a claim limitation is not literally met, but the corresponding structure in the accused product, or the corresponding step in the accused process, “performs substantially the same function, in substantially the same way, to achieve the same result,” the claim may still be infringed.
THE FESTO CASE
- The Court of Appeals for the Federal Circuit (CAFC) has created Festo (Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., Ltd., 234 F.3d 558 [Fed. Cir. 2000])
- Eliminated ALL equivalents of any claim limitation that had been amended during prosecution.
- Effectively eliminated the doctrine of equivalents with respect to any claim limitation that was amended during the course of prosecution of the patent.