Federal Circuit Invalidates Means-Plus-Function Claims For Computer-Implemented Inventions

Functional claim language—which defines an invention by what it does rather than what it is—can be a powerful claim drafting tool when used carefully. For example, functional language may be advantageous for computer-implemented inventions that are characterized with reference to logical components instead of physical hardware. 35 U.S.C. § 112(f) (formerly § 112¶ 6) expressly permits the use of functional claiming and is traditionally invoked by the phrase "means for" followed by a functional modifier. But even when the term "means" is not used, other terms that are not understood by persons of ordinary skill in the art to indicate structure, such as "module," mechanism," "element," or "device," are likely to invoke § 112(f). See e.g., Williamson v. Citrix Online, LLC, 792 F.3d 1339, 1350 (Fed. Cir. 2015).