By Nika Aldrich

In a recent case, Williamson v. Citrix Online, LLC, — F.3d —, (Fed. Cir. June 16, 2015) (“Williamson II”), the en banc Federal Circuit overruled several prior opinions and lowered the standard used to determine whether a claim term is subject to Section 112(f).[1] As a result, the original panel reversed itself and found that a patent claim limitation using the word “module,” but not the term “means,” was subject to Section 112(f), and invalidated the claims. A subsequent panel held that a term in a different patent using the word “mechanism” was subject to Section 112(f), and invalidated the claims. These decisions mark a change in Federal Circuit jurisprudence regarding attempts by patentees to avoid articulating the structures covered by their patents.

The issue relates to so-called “nonce” terms in claims — words that do not connote a specific structure, such as “unit,” “device,” “mechanism,” “module,” “component,” “element,” “member,” “apparatus,” “machine,” or “system.” Patentees may use these nondescript terms in their claims to broaden the scope of the claims to cover any structure for performing a particular function. But, as with the term “means,” these terms may not connote sufficiently definite structure to those with ordinary skill in the art, and the patent office and the courts may limit the breadth of these terms to the associated structures in the specification under Section 112(f).

The Requirement That Claim Terms Recite Structure, Either Directly Under § 112(b) or Indirectly Under § 112(f)

The patent system represents a quid pro quo with the government: In exchange for fully disclosing a new invention, the inventor is granted monopoly rights to his idea for a period of time.[2] But the inventor “must describe the exact scope of an invention and its manufacture to secure to the patentee all to which he is entitled, and to apprise the public of what is still open to them.”[3] Thus, the claims must “particularly point[] out and distinctly claim[] the subject matter which the inventor … regards as the invention.”[4] To achieve this, a patentee must draft claims that put the public on notice of the structure of the device itself, not merely its function.[5]

Generally, it is in patentees’ best interests to seek broad claims that cover as much as possible; thus, the requirement to identify specific structures is limiting. Patentees would prefer to claim any and all ways of performing a particular task, not just the specific structure that the inventor identified at the time of his invention. Accordingly, a common approach is to claim, rather than a specific structure, any means for performing a given function. And the patent laws allow “means-plus-function” claims drafted in this format as an alternative to naming the specific structures in the claims. But “[i]n exchange for being able to draft a claim limitation in purely functional language, the applicant must describe in the patent specification some structure which performs the specified function.”[6] Moreover, “the functional claim language covers only the corresponding structure, material, or acts described in the specification and equivalents thereof.”[7]

Additionally, some terms that are subject to § 112(f) are subject to a further requirement. For claims in which the function is performed by a specially programmed computer, “the structure disclosed in the specification [must] be more than simply a general purpose computer or microprocessor.”[8] Instead, “the specification [must] disclose an algorithm for performing the claimed function.”[9] Section § 112(f) then limits the claim term to use of the algorithm (the corresponding structure) for performing the claimed function.

Claim limitations that are not drafted in “means-plus-function” language are not subject to such treatment. There is no “algorithm” requirement for non-means-plus-function claim terms and, other than for means-plus-function claim terms, it is in fact improper to “import[] limitations from the specification into the claims.”[10]

Thus, inventors often aim to cover the greatest breadth in a claim without having it subject to Section 112(f), which limits the claim to the structures disclosed in the specification.

Generic Claims Terms Other Than “Means” May Invoke § 112(f)

To avoid having claims subject to Section 112(f), some patentees have used nondescript words other than “means” in their claims. This is because the Federal Circuit “has long recognized the importance of the presence or absence of the word ‘means.'”[11] Under Federal Circuit precedent, “the use of the word ‘means’ in a claim element creates a rebuttable presumption that § 112[f] applies” and that “the failure to use the word ‘means’ also creates a rebuttable presumption … that § 112[f] does not apply.”[12]

Thus, rather than reciting “means for” performing a function, patentees have come to use terms such as “element for” or “device for” performing the function instead. The list of such generic terms has grown over the years. And although the Manual of Patent Examining Procedure notes that “mechanism for,” “module for,” “device for,” “unit for,” “component for,” “element for,” “member for,” “apparatus for,” “machine for,” or “system for” are “nonstructural generic placeholders that may invoke … 35 U.S.C. [§] 112[f],”[13] the presumption is still that § 112(f) does not apply.

The Federal Circuit has addressed the use of these “nonce” terms on multiple occasions. In Mass. Inst. of Tech., v. Abacus Software, 462 F.3d 1344 (Fed. Cir. 2006) (“MIT”), the Court held that “[t]he generic terms ‘mechanism,’ ‘means,’ ‘element,’ and ‘device,’ typically do not connote sufficiently definite structure,” and are therefore subject to Section 112[f].[14] In subsequent cases, the court also found § 112[f] to apply in Welker Bearing Co. v. PHD Inc., 550 F.3d 1090, 1096-97 (Fed. Cir. 2008) (“mechanism for moving said finger” subject to § 112 ¶ 6); Aspex Eyewear Inc. v. Altair Eyewear Inc., 288 Fed. Appx. 697, 703-4 (Fed. Cir. 2008) (“retaining mechanism” subject to § 112 ¶ 6).

Recently, in Robert Bosch LLC v. Snap-On Inc., 769 F.3d 1094 (Fed. Cir. 2014), the Federal Circuit held that “program recognition device” and “program loading device” were subject to § 112(f). The court noted that the specification did “not contain a single reference to the structure of the claimed “devices” — that the specification referred only to the function of these “devices.”

But, consistent with the presumption from not using the word “means,” in most cases to address such terms, courts have found that § 112(f) does not apply.[15]

For example, in Personalized Media Comms. v. Int’l Trade Com’n, 161 F.3d 696 (Fed. Cir. 2004), the court held that the term “digital detector” was not a means-plus-function claim term subject to § 112[f]. The court held that the presumption from not having the word “means” was not overcome: “‘Detector’ is not a generic structural term such as ‘means,’ ‘element,’ or ‘device’; nor is it a coined term lacking a clear meaning, such as ‘widget’ or ‘ram-a-fram.'”[16] Likewise, in Lighting World Inc. v. Birchwood Lighting Inc., 382 F.3d 1354 (Fed. Cir. 2004), the Federal Circuit held that “connector assembly” was not a means-plus-function term subject to Section 112[f].[17] In most cases to address the issue, nonce terms were not subject to § 112(f).[18]

The Increasing Burden to Prove Claim Terms are Subject to 112(f)

Over time, the Federal Circuit has also increased the burden on defendants seeking to show that claim terms not including “means” are subject to 112(f). In Lighting World, decided in 2004, the court held that “the presumption flowing from the absence of the term ‘means’ is a strong one that is not readily overcome.”[19] In Inventio AG, the court held that, to rebut this strong presumption, it must be demonstrated that “skilled artisans, after reading the patent, would conclude that [the] claim limitation is so devoid of structure that the drafter constructively engaged in means-plus-function claiming.”[20] And in Flo Healthcare, decided in 2012, the court held that “[w]hen the claim drafter has not signaled his intent to invoke § 112[f] by using the term ‘means,’ we are unwilling to apply that provision without a showing that the limitation essentially is devoid of anything that can be construed as structure.”[21]

The Federal Circuit Reverses Course in Williamson, Reducing the Burden

Applying this heightened standard, in Williamson v. Citrix Online LLC, 770 F.3d 1371, 1378 (Fed. Cir. 2014) (“Williamson I”), a three-judge panel of the Federal Circuit held that “distributed learning control module” was not subject to § 112[f].

On a motion for rehearing en banc, the Federal Circuit reversed. The court observed that the result of creating a “strong” presumption was “a proliferation of functional claiming untethered to § 112[f] and free of the strictures set forth in the statute.” The en banc held that “such a heightened burden is unjustified” and it “expressly overrule[d] the characterization of that presumption as ‘strong.'”

The court noted that “the essentially inquiry is not merely the presence or absence of the word ‘means’ but 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.”[22]

On Rehearing, the Panel Applied § 112[f]

Revisiting the case with the new standard, the panel majority in Williamson II reversed itself, holding that “distributed learning control module” was subject to § 112[f]. The court found that the claim term was part of a longer phrase that recited functions performed by the “distributed learning control module,” and was therefore drafted “in a format consistent with traditional means-plus-function claim limitations.”

The court further found that the word “means” was merely replaced with the term “module,” and that the use of the word “module” merely sets forth “the same black box recitation of structure for providing the same specified function as if the term ‘means’ had been used.” Relying on MIT, the court also observed that the term “‘[m]odule’ is a well-known nonce word that can operate as a substitute for ‘means’ in the context of § 112[f]. Moreover, the prefix “distributed learning control” did “not impart structure into the term ‘module.'”

The court noted that there were some indications of structure in the claim and in the specification. For example, the court noted that “portions of the claim do describe certain inputs and outputs at a very high level,” and that the module was “described in a certain level of detail in the written description.” In Williamson I, these indications of structure were enough to rebut the presumption that § 112[f] applied.[23] There, the court held that “proper weight [must be given] to the surrounding context of the rest of the claim language and the supporting text of the specification,” and “[w]hile the supporting specification describes the claimed expression “distributed learning control module” in a high degree of generality, in some respects using functional expressions, it is difficult to conclude that it is devoid of structure.”

On rehearing, however, the panel majority held that “the written description fail[ed] to impart any structural significance to the term” and that the claim language did not “inform the structural character of the limitation-in-question or otherwise impart structure” to the term. Thus, the lowered presumption was significant: although the descriptions of the module in the specification showed that the term was not “devoid of structure,” which was enough to avoid § 112(f) under the stronger presumption, it was not enough to “inform the structural character” of the term, as required following the en banc decision.

The court also considered a declaration of an expert in the field, who testified that the term “distributed learning control module” connoted a structure. The court, however, was unpersuaded. The expert “fail[ed] to describe how the distributed learning control module, by its interaction with the other components in the [system], is understood as the name for structure.” The expert also said that the structure could be computer hardware or software, but the court held that “the fact that one of skill in the art could program a computer to perform the recited functions cannot create structure where none otherwise is disclosed.”

Holding that § 112[f] applies, the court considered whether there was a corresponding algorithm to provide the requisite structure. Finding none, the panel held the claims were indefinite.

In a Subsequent Case, the Panel Followed Williamson and Applied § 112[f]

Shortly after Williamson II was decided, a separate panel of the Federal Circuit, in Media Rights Techs. v. Capital One Financial Corp.[24] considered whether the claim term “compliance mechanism” is subject to § 112[f]. The court noted that “‘compliance mechanism’ has no commonly understood meaning and is not generally viewed by one skilled in the art to connote a particular structure.”[25]

The court also distinguished the term “compliance mechanism” from the term “modernizing device,” which was found to connote structure in Inventio. The court held that, unlike in Inventio, “compliance mechanism” was not a “substitute for an electrical circuit, or anything else that might connote a definite structure.” And, although the specification explained how the “compliance mechanism” was connected to other components of the system, it did not explain how the “compliance mechanism” and the other components operated collectively as a circuit, as did the specification in Inventio. The court also noted that Inventio was decided under the older standard, which had been superseded in Williamson.[26]

The court also noted that it had never found the term “mechanism” to be an identifiable structure, and that merely adding the modifier “compliance” was not enough imbue it with structure. Applying § 112[f], the court considered whether there was a corresponding algorithm to provide the requisite structure. Finding none, as in Williamson II, the claims were held indefinite.

Conclusion

Williamson marks an important turn for the Federal Circuit in addressing the use of “nonce” terms in patent claims to avoid treatment under § 112(f). Moreover, the contrast between the two panel decisions, before and after the en banc ruling, and the subsequent Media Rights case illustrate how the different levels of presumption apply in practice. No longer does a claim term with a nonce word need to be “devoid of structure” for § 112(f) to apply. Instead § 112(f) should apply unless a term is understood by those of ordinary skill in the art as “the name for [a] structure.”[27]

As published in Law 360, September 28, 2015.