By Jason Rantanen
Inventio AG v. ThyssenKrupp Elevator Americas Corporation (Fed. Cir. 2011) Download 10-1525
Panel: Lourie (author), Prost, Moore
Patent claims may be indefinite due to their use of functional language untethered to any structure. Prevailing on such an argument, however, can be quite difficult, as Inventio v. ThyssenKrupp illustrates.
The patents in this case relate to a device that allows elevator passengers to enter their floor destination as they call for the elevator. Central to the claimed invention are two components: a "computing unit," which processes the passenger's input, and a "modernizing device," which acts as an intermediary between the computing unit and the elevator control. During claim construction, the district court concluded that both claim terms "lacked sufficient structure to avoid § 112 ¶ 6," slip op. at 7, further holding that they were indefinite because the written description failed to disclose corresponding structure to perform the recited functions. Inventio appealed.
Strong Presumption Against Means Plus Function Construction
Patentees are permitted to include purely functional language in their claims under § 112 ¶ 6. Under that provision, such limitations "shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof." Slip Op. at 9. Whether § 112 ¶ 6 applies depends principally on whether the limitation uses the term "means." When that term is not used, "we presume that the limitation does not invoke § 112 ¶ 6." Id. The presumption "is a strong one that is not readily overcome." Id. at 10.
Presumption Not Overcome
Given the absence of the term "means" in the disputed limitations, the court focused its analysis on whether ThyssenKrupp had overcome the "strong presumption" against application of § 112 ¶ 6, concluding that it had not. In reaching this conclusion, the court agreed with Inventio that it should consider the written description in determining whether the claims recite sufficient structure. "[I]t is proper to consult the intrinsic record, including the written description, when determining if a challenger has rebutted the presumption that a claim lacking the term "means" recites sufficiently definite structure." Slip Op. at 12. Applying this rule, the court found that the terms "modernizing device" and "computing unit" provided, at least in the context of the two patents at issue, sufficient structure:
"In this case  the claims recite a “modernizing device,” delineate the components that the modernizing device is connected to, describe how the modernizing device interacts with those components, and describe the processing that the modern-izing device performs. The written descriptions addition-ally show that the modernizing device conveys structure to skilled artisans. Thus, this is not a case where a claim nakedly recites a “device” and the written description fails to place clear structural limitations on the “device.”"
Slip Op. at 15. The CAFC applied similar reasoning to "computing unit."
Is The Court Effectively Applying a Presumption Against Indefiniteness of Functional Claim Elements?
Under Supreme Court precedent, a claim may be invalid for indefiniteness if it contains functional claim limitations. See General Electric Co. v. Wabash Appliance Corporation, 304 U.S. 364, 371 (1938); United Carbon Co. v. Binney & Smith Co., 317 U.S. 228, 234 (1942); c.f. Halliburton Energy Services, Inc. v. M-I LLC, 514 F.3d 1244, 1255 (Fed. Cir. 2008). Section 112 ¶ 6 provides the exception discussed above.
I question how viable this aspect of the indefiniteness doctrine is in practice, however, at least under the Federal Circuit's current approach. Under cases such as Inventio, the CAFC's framework for analyzing indefiniteness based on functional claiming operates like this: (Question One) Is this a means-plus-function claim element? If No, then it is not indefinite. If Yes, (Step Two) Does the written description recite sufficient structure? If No, the claim is indefinite; if Yes, it is not. Since there is a strong presumption in favor of answering "No" to Question One unless the term "means" is used, the effective result is a strong presumption against indefiniteness unless the patent drafter elects otherwise. This makes it extremely difficult for a party challenging the definiteness of a functional claim element to prevail, and seems somewhat inconsistent with the broader ideas of General Electric and United Carbon.
I could see the CAFC's rule as perhaps being justified on the ground that patents are entitled to a presumption of validity, and the indefiniteness issue is, after all, one type of validity analysis. But that does not appear to be how the court has justified its rule thus far. Instead, it has treated it solely as a claim construction question in which deference is given to the patent drafter's choice of language.
ThyssenKrupp's Motion to Strike
Following the completion of merits briefing, ThyssenKrupp filed a motion to strike portions of Inventio's reply brief on various grounds, including that it contained new and misleading arguments about the disclosure of the '861 and '465 patents. Unimpressed by ThyssenKrupp's motion, the court rejected it. "ThyssenKrupp simply disagrees with Inventio's legal arguments, and its motion seems to us to be an improper attempt to obtain the final word in the appeal, a practice that we strongly discourage." Slip Op. at 3. FIling such a motion, the court commented, "borders on the type of frivolous and wasteful litigation tactics that we have previously frowned upon." Id.
Update: For those interested in reading the offending brief, a copy can be downloaded here: Download SchmitMotionToStrike. Thanks to Hal Wegner for circulating a copy in his email newsletter.