TAKEAWAY: It is a well-established presumption that a failure to use “means” does not invoke pre-AIA 35 U.S.C. § 112, para. 6 (now 35 U.S.C. § 112(f)). The recent Federal Circuit Williamson ruling, however, warns patent applicants wishing to steer clear of a means-plus-function claim interpretation to avoid generic words and instead recite sufficiently definite structure for performing a claimed function.

In Williamson v. Citrix Online, LLC, et al., No. 2013-1130 (Fed. Cir. June 16, 2015), the Federal Circuit reviewed the construction of the following claim term in a system for conducting distributed learning among computer systems coupled to a network:

  • a distributed learning control module for receiving communications transmitted between the presenter and the audience member computer systems and for relaying the communications to an intended receiving computer system and for coordinating the operation of the streaming data module.

The district court had construed the term as a means-plus-function term, found that the specification failed to disclose algorithms for performing the claimed functions, and therefore invalidated the claim under 35 U.S.C. § 112, para. 2.

The Federal Circuit affirmed those rulings. An en banc panel first set forth the well-established presumption that failure to use “means” creates a rebuttable presumption that 35 U.S.C. § 112, para. 6, does not apply. The en banc panel then overruled Lighting World, Inc. v. Birchwood Lighting, Inc., 382 F. 3d 1354 (Fed. Cir. 2004), which held that the presumption flowing from the absence of “means” is a strong one that is not readily overcome. The panel stated that this heightened burden is unjustified, and that characterizing the presumption as “strong” should be abandoned. Instead, courts should apply the presumption without requiring any heightened evidentiary showing. The standard is whether the words of the claim are understood by persons of ordinary skill in the art to have a sufficiently definite meaning as the name for structure. The presumption can be overcome if the challenger demonstrates that the claim term fails to recite sufficiently definite structure or else recites function without reciting sufficient structure for performing that function.

The Federal Circuit then held that the claim limitation in question is consistent with traditional means-plus-function format. The Court noted that the term “module” is a well-known nonce word that can operate as a substitute for “means.” It is a generic description for software or hardware that performs a function and, here, it does not indicate any structure because it sets forth the same black box recitation of structure as “means.” The Court also stated that the prefix “distributed learning control” does not impart any structure. The Court further noted that other generic terms–like mechanism, element, and device–do not connote sufficiently definite structure, and therefore may invoke 35 U.S.C. § 112, para. 6. The Court held that the claim limitation does not recite sufficiently definite structure, and the presumption against means-plus-function is rebutted—the limitation is subject to 35 U.S.C. § 112, para. 6. The Court next determined that the specification did not disclose sufficient structure that corresponds to the claimed functions, and therefore held the claim invalid under 35 U.S.C. § 112, para. 2.

The Williamson case reminds practitioners that a patent application should set forth a variety of claim formats and terminology, to obtain a variety of scopes of protection and account for ever-changing law. If a patent applicant wishes to avoid means-plus-function constructions, the applicant should avoid functional language, recite sufficient structure to perform recited functions, and/or avoid generic words, like mechanism, device, module, and element.