In a new precedential Federal Circuit decision, Kyocera Senco Industrial Tools Inc. v. ITC, that impacts both patent prosecutors and litigators, the court again demonstrated the reach of its recent expansion of language that might render claim language as a “means plus function” limitation.  The decision provides further evidence that those drafting patent applications will need to take greater care in crafting language to support claims with this new standard in mind, and intellectual property litigators will need to more carefully examine claims they seek to assert or defend against in court.

Section 112(f) ¶ 6 of Title 35 (previously section 112 ¶ 6) provides that a patent claim may be drafted “as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof.”  Such “means plus function claims” are limited in scope to the structure, materials or acts described in the patent specification as corresponding to the claimed function.  In this way, means plus function claims typically have a narrower reach than other claims.

With its decision in Williamson v. Citrix Online, LLC, 792 F.3d 1339 (Fed. Cir. 2015) (en banc), the Federal Circuit established the current framework for determining whether a properly construed claim falls within section 112 ¶ 6.  Departing from previous standards, the court held that a claim may be given a mean plus function construction even if it does not use the word “means” or “steps.”  The absence of such words creates a “rebuttable presumption” that a claim is not a means plus function claim, but the presumption can be overcome by a showing that “the claim term fails to recite sufficiently definite structure or else recites function without reciting sufficient structure for performing that function.”  Id., at 1348.  Since the Williamson holding, courts have construed a variety of terms as creating means plus function limitations where the term “means” is not recited in the claims.  See, e.g., MTD Prods. Inc. v. Iancu, 933 F.3d 1336, 1345 (Fed. Circ. 2019) (“mechanical control assembly”); Diebold Nixdorf, Inc. v. ITC, 899 F.3d 1291, 1302 (Fed. Cir. 2018) (“cheque standby unit”); Advanced Ground Info., Sys. Inc. v. Life360, Inc., 830 F.3d 1341, 1347-48 (Fed. Cir. 2016) (“symbol generator”).

In a recent precedential decision, the Federal Circuit again took up the issue of whether to treat a claim limitation that does not use the word “means” as a means plus function limitation under 35 U.S.C. § 112 ¶ 6.  Kyocera Senco Industrial Tools Inc. v. ITC, — F. 4th —, 2022 WL 189822 (Fed. Cir. Jan. 21, 2022).  Kyocera initiated the case by filing a complaint with the ITC claiming that Koki Holdings America Ltd. infringed five patents generally relating to gas spring nailer products.  After protracted proceedings, the Commission ultimately found that Koki infringed the Kyocera patents and that the patents were not invalid.  Both parties appealed.  In an opinion that addressed a number of issues, including the qualifications of one of Kyocera’s experts and several of the Commission’s claim constructions, the Federal Circuit vacated and remanded the Commission’s findings.

Of particular interest, the court concluded that section 112, ¶ 6 should be applied to the claim term “lifted member” and reversed the ITC’s contrary decision.  Applying the guidance from Williamson, the court stated:

A person of ordinary skill in the art would not understand the claimed “lifter member” to have “a sufficiently definite meaning as the name for a structure.” See Williamson, 792 F.3d at 1349. That phrase, alone, does not connote structure. It is a non-structural generic placeholder (member) modified by functional language (lifter).

Kyocera, 2022 WL 189822, at *7.  The court further noted that “[n]othing in the written description [of the patents] provides a clear and unambiguous definition of ‘lifter member.’”  Id., at *8.  Accordingly, the court held that “§ 112 ¶ 6 applies to the ‘lifter member’ limitation, and it must be construed to cover only ‘the structure, materials, or acts described in the specification as corresponding to the claimed function and equivalents thereof.’”  Id.  Because the parties had not fully briefed the section 112 ¶ 6 issue, the court remanded the case to the ITC.

The Kyocera case is the latest example of the Federal Circuit’s renewed scrutiny of claims for means plus function treatment.  Because of the court’s position on means plus function claims, prosecutors need to exercise greater care to either avoid the broader applicability of section 112 ¶ 6 or to ensure that the specification sufficiently describes one or more corresponding structures to support the means plus function claim language, and clearly associates the claimed functions with the structures in the specification.  Likewise, litigation counsel should carefully evaluate asserted patent claims to identify terms that may be subject to means plus function treatment and to ascertain whether those terms are supported by a corresponding structure disclosed in the specification.