The U.S. Court of Appeals for the Federal Circuit reversed a district court’s summary judgment ruling that two contested patent claim terms were means-plus-function limitations and that the written description of the patents failed to disclose any corresponding structure.  Inventio AG v. ThyssenKrupp Elevator Americas Corp., Case No. 10-1525 (Fed. Cir., June 15, 2011) (Lourie, J.).

Plaintiff Inventio sued defendant ThyssenKrupp Elevator alleging infringement of two patents relating to a modernized elevator.  The elevator claims are directed to a structure that allows a passenger to call an elevator and request a desired destination, all from the boarding floor.  In relevant part, the patents claim and describe a “modernizing device” and “computing unit” as components that are central to the operation of the claimed modernized elevator system.

After a Markman hearing, the lower court concluded that the terms “modernizing device” and “computing unit” were means-plus-function claim elements, as they did not recite any structure but were purely functional.  The district court then concluded that both claim terms were indefinite because the written descriptions failed to disclose corresponding structure to perform the recited functions.  Inventio appealed.

The issue on appeal was whether the terms in issue are mean-plus-function limitations that fall within the ambit of §112, ¶6.  Given that neither disputed claim term included the word “means,” the Federal Circuit noted that there is a rebuttable presumption that §112, ¶6 does not govern.  This presumption, stated the Court, can only be overcome if ThyssenKrupp demonstrated that the claim terms fail to recite sufficiently definite structure.  The parties disputed whether, for purposes of determining whether sufficient structure was recited, it was proper to view the disputed claim language in light of the written description, as Inventio argued, or whether the analysis is limited to the claim language itself, as ThyssenKrupp argued.

In view of the general principle that claims should always be interpreted in light of the written description, the Federal Circuit concluded that the same holds true for a means-plus-function analysis.  In deciding whether a challenger has rebutted the presumption, the Court stated that “the focus remains on whether the claim as properly construed recites sufficiently definite structure to avoid the ambit of §112, ¶6.”  (Emphasis added.)  Under Phillips, the Court concluded, the proper construction of claim terms necessarily requires analysis of the entire intrinsic record.

Using this approach, the Federal Circuit found that the written description of the patent supported the conclusion that the claimed “modernizing device” was not a purely functional limitation and that ThyssenKrupp failed to overcome the presumption that the claim term was not a means-plus-function limitation.  Similarly, the Court concluded that the claimed “computing unit” was also presumptively not a mean-plus-function claim element and connoted sufficiently definite structure to someone of skill in the art so as to avoid falling under §112, ¶6.

Practice Note:  Prior to addressing the merits, the Court denied the appellee’s motion to strike portions of Inventio’s reply brief, stating that “filing of this motion borders on the type of frivolous and wasteful litigation tactics that we have previously frowned upon.”  The Federal Circuit warned against the practice of appellee’s attempting to obtain the final word in an appeal when an appellee merely disagrees with the appellant’s legal arguments.  The Court noted appellee’s “nasty tone” and excessive use of the terms “blatant” and “blatantly.”