Claim Terms Held Are Not Means-Plus-Function Limitations When Claim Language, In View Of Written Description, Recites Sufficiently Definite Structure

Article by Hin M. Au*

This article previously appeared in Last Month at the Federal Circuit Newsletter, July 2011

Judges: Lourie (author), Prost, Moore

[Appealed from D. Del., Judge Robreno]

In Inventio AG v. ThyssenKrupp Elevator Americas Corp., No. 10-1525 (Fed. Cir. June 15, 2011), the Federal Circuit reversed and remanded the district court's grant of SJ of invalidity based on a determination that certain claim limitations were means-plus-function limitations subject to 35 U.S.C. § 112, ¶ 6 and were indefinite for lack of disclosure of corresponding structure.

Inventio AG ("Inventio") sued ThyssenKrupp Elevator Americas Corporation, ThyssenKrupp Elevator Corporation, and ThyssenKrupp Elevator Manufacturing Incorporated (collectively "ThyssenKrupp") for infringement of U.S. Patent Nos. 6,892,861 ("the '861 patent") and 6,935,465 ("the '465 patent"). The patents are directed to a modernized elevator system that allows a passenger at the boarding floor to enter the desired destination when requesting an elevator instead of just pressing an up or down arrow. The patents also disclose a process for modernization that replaces the original floor call transmitters (the "up/down" buttons) with new floor terminals incorporating the modernized elevator system. In addition, the patents disclose the back-end technology ("modernizing device" and "computing unit") that interfaces with both the new floor terminals and the conventional elevator control to operate the modernized elevator system. Specifically, the written descriptions show how the "computing unit" and the internal components of the "modernizing device" are connected to each other and to the elevator control, and how the modernized elevator system functions during operation. During claim construction, the district court concluded that the terms "modernizing device" and "computing unit" were indefinite. In reaching this conclusion, the district court concluded that both terms lacked sufficiently definite structure to avoid 35 U.S.C. § 112, ¶ 6.

On appeal, the Federal Circuit first explained that the word "means" is central to the means-plus-function claim analysis. First, "[t]he use of the term 'means' triggers a rebuttable presumption that § 112, ¶ 6 governs the construction of the claim term." Slip op. at 9 (citing TriMed, Inc. v. Stryker Corp., 514 F.3d 1256, 1259 (Fed. Cir. 2008)). "Conversely, where, as here, the claim language does not recite the term 'means,' [the Court]...