Reconstructing Claim Construction: How the Court of Appeals for the Federal Circuit Dismantled Functional Claiming, and How to Bring It Back

A patent’s claims are not interpreted in a vacuum. Rather, they are read in light of the specification. Claims are typically defined in terms of “structure,” i.e., what the invention is; however, a narrow exception—set forth in 35 U.S.C. § 112(f)—allows inventors to define elements of a claim in terms of “function,” i.e., what the invention does. While it is axiomatic that courts should not construe a claim to protect only the embodiments disclosed in the specification, Congress enacted this functional claiming statute as a narrow exception, limiting claims to protect only the structures disclosed in the specification that perform the function recited in the claim. This Note argues that the Court of Appeals for the Federal Circuit effectively rejected Congress’s mandate by blurring its definition of “structure” such that § 112(f) now seldom, if ever, applies. As a result, inventors may use technical definitions devoid of structure or offer a specific solution to a general problem to obtain overly broad patent protection. This Note discusses the evolution of the court’s method of claim construction before discussing the lasting, detrimental effects of two decisions. It then proposes a new analytical framework for the Federal Circuit that both respects the will of Congress and returns claim interpretation to its original legal principles.