Federal Circuit Decreases Strength of Presumption Against Treatment of Patent Claims as Means-Plus-Function

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Accused infringers challenging patent claims now have a new arrow in their quiver as a result of yesterday's holding in Williamson v. Citrix Online, et al.1 In an en banc decision, the Federal Circuit replaced an earlier three-judge panel opinion and construed the patent claim term "distributed learning control module" as an indefinite means-plus-function limitation. In its ruling, the Federal Circuit considered the burden to rebut one of two presumptions created by 35 U.S.C. § 112, para. 62 that functional claim limitations without the word "means" are not means-plus-function limitations. Prior to the decision in Williamson, this presumption was a strong one that was seldom rebutted. Under this standard, patent drafters avoided the use of the term "means," and challengers faced a difficult burden in arguing indefiniteness.

Yesterday, the majority reverted to its previous precedent and refused to apply a heightened standard in determining whether a claim term that does not use the word "means" can nonetheless be interpreted as a means-plus-function limitation. Prior Federal Circuit precedent emphasized whether the words of a claim would be "understood by persons of ordinary skill in the art to have a sufficiently definite meaning as the name for structure."3 The Williamson holding reinstates this standard.

Background of the Case

Owned by Richard A. Williamson as trustee for the At Home Corporation Bondholders' Liquidating Trust, U.S. Patent No. 6,155,840 (the "'840 patent") describes a system and method for distributed learning that uses standard computer hardware and software connected over a network to construct a "virtual classroom" environment. The aim of the invention is to link one or more presenters with a geographically remote audience.

Independent claim 8 from the '840 patent claims a "distributed learning control module" that receives communications between the presenter and audience computer systems, relays those communications to a receiving computer, and coordinates the operation of a streaming data module. At the district court level, the defendants argued that this term was a means-plus-function limitation under 35 U.S.C. § 112, para. 6. The district court agreed and held that claim 8 and its dependent claims were invalid as indefinite under § 112, para. 2. Williamson conceded to this ruling and stipulated to the entry of final judgment.

Williamson appealed, challenging the court's claim construction. Last November, a three-judge Federal Circuit panel reversed the district court's construction, finding that the failure to use the word "means" in the limitation created a strong rebuttable presumption that the term was not a means-plus-function limitation. Yesterday, the Federal Circuit withdrew this opinion and substituted a new one, addressing en banc the § 112, para. 6 issue.

The Federal Circuit's Analysis of the Functional Claiming Standard

Patent claims drafted in a particular manner invoke the application of 35 U.S.C. § 112, para. 6, which provides that when "[a]n element in a claim for a combination [is] expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, [] such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof." Put simply, if a patentee elects to express a claim limitation as a function rather than a structure for performing a function, the limitation is construed narrowly to only cover that disclosed in the specification and equivalents.

The use of the term "means" in a claim element creates a rebuttable presumption that the statute applies. The absence of the term creates a converse rebuttable presumption—that § 112, para. 6 does not apply.

Starting with Lighting World, Inc. v. Birchwood Lighting, Inc.,4 the Federal Circuit has slowly heightened the standard applied to the presumption flowing from the absence of the term "means." In Lighting World, the Federal Circuit characterized the presumption as "a strong one that is not readily overcome." The appellate court reiterated this standard in Inventio AG v. ThyssenKrupp Elevator Americas Corp.5 One year later, the Federal Circuit raised the bar even higher, declaring that "[w]hen the claim drafter has not signaled his intent to invoke § 112, ¶ 6 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."6 Finally, just a year ago, the court noted that it has "'seldom' held that a limitation without recitation of 'means' is a means-plus-function limitation."7

These cases established a heightened bar to overcome the presumption that a functional limitation expressed without using the word "means" is not subject to § 112, para. 6. Finding this heightened standard "unjustified," "unwarranted," "uncertain in its meaning and application," and with the "inappropriate practical effect of placing a thumb on what should otherwise be a balanced analytical scale," the Williamson en banc court overruled its precedent in an 11-1 decision. The panel emphasized a return to the application of the presumption prior to the Lighting World ruling.

Pre-Lighting World cases emphasized whether the words of a claim would be "understood by persons of ordinary skill in the art to have a sufficiently definite meaning as the name for structure."8 Where a claim term lacks the word "means," § 112, para. 6 will apply if the challenger demonstrates that a functional limitation "fails to 'recite sufficiently definite structure' or else recites 'function without reciting sufficient structure for performing that function.'"9

In applying the standard to the disputed claim phrase "distributed leaning control module," the Federal Circuit affirmed the district court's finding of invalidity due to indefiniteness. The majority observed that the phrase replaces the term "means" with the well-known nonce word "module" that can operate as a substitute for § 112, para. 6 purposes. Other generic terms like "mechanism," "element," and "device" operate similarly and are "nothing more than verbal constructs . . . tantamount to using the word 'means.'"

Practical Effects

In her dissent, Judge Newman declared that the majority's decision creates a "litigator's delight" of § 112, para. 6. Judge Newman urged the adoption of a simpler standard.

Uncertainty exists regarding the application of this new standard; however, the majority did create an inroad for patent challengers. Refusing to construe the presumption as a strong one lessens the standard and may make functional claim limitations more susceptible to invalidation under § 112, para. 6. Additionally, the Williamson decision states that certain nonce words used by patent drafters, such as "module," "mechanism," "element," and "device," may be used "in a claim in a manner that is tantamount to using the word 'means'" because the words typically do not "connote sufficient definite structure."10 Issued patent claims are left subject to attack while drafters adjust to the change.

Functional claiming is common in software patents. While patents drafted in the last 10 years potentially now will be challenged under the new rule, many software patents were written in the 1990s, prior to Lighting World. Thus, the Federal Circuit's holding may affect some existing patents, and a larger group of pending patent applications.

 

1 No. 13-1130, slip op. (Fed. Cir. June 16, 2015).

2 After the filing of the '840 patent, the statute was amended to 35 U.S.C. § 112(f).
3 Slip op. at 14.
4 382 F.3d 1354, 1358 (Fed. Cir. 2004).
5 649 F.3d 1350, 1358 (Fed. Cir. 2011).
6 Flo Healthcare Solutions, LLC v. Kappos, 697 F.3d 1367, 1374 (Fed. Cir. 2012).
7 Apple Inc. v. Motorola, Inc., 757 F.3d 1286, 1297 (Fed. Cir. 2014).
8 Williamson, slip op. at 14.
9 Id. (citation omitted).
10 Williamson, slip op. at 17.

DISCLAIMER: Because of the generality of this update, the information provided herein may not be applicable in all situations and should not be acted upon without specific legal advice based on particular situations.

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