The Court of Appeals for the Federal Circuit is justifiably credited with the restoration of the prestige and enforceability of patents. However, in recent rulings regarding the doctrine of equivalents, it has returned to a realm of uncertainty which had once characterized the law of patents. In its current application, the doctrine of equivalents as a tool of equity is subject to inconsistent standards and rationales. Such inconsistency undermines the equitable underpinnings of the doctrine,· which themselves have for some time been involved in an ideological "tug of war." The task of applying the doctrine of equivalents to determine patent infringement has presented the Federal Circuit with a dilemma by requiring it to ascertain the breadth of a given scientific and technological breakthrough while using a description which is mainly grammatical in form. Unfortunately, the doctrine lacks clear guidelines for implementation from either statutory or common law to overcome this dilemma.
Roy Collins III,
The Doctrine of Equivalents: Rethinking the Balance Between Equity and Predictability, 22 Golden Gate U. L. Rev.