In MasterMine Software, Inc., v. Microsoft Corp., [2016-2465](October 30, 2017), the Federal Circuit affirmed the court’s claim construction, but reversed the court’s indefiniteness determination, and remanded for proceedings consistent with its opinion.

U.S. Patent Nos. 7,945,850 and 8,429,518 describe a process by which an electronic worksheet is automatically created. The district court construed the term “pivot table,” resulting in a stipulation of non-infringement. The district court also agreed with Microsoft that certain of the claims were indefinite for improperly claiming two different subject-matter classes.

On appeal, MasterMine argued the district court’s construction of pivot table was incorrect because it excludes tables that do not display data. However, the Federal Circuit found that each time the claims recite the generation of a pivot table, they further recite within the same limitation that the generated pivot table contains data or presents data. The Federal Circuit further found that the specification further supports the district court’s construction, noting that in the context of the invention is to display data that can be viewed, summarized, and manipulated by users, and such user action is available upon the generation of the pivot tables. The Federal Circuit further found that prosecution history of the patents provides additional support for the district court’s construction. Finally, the Federal Circuit found that MasterMine’s arguments in support of its contrary claim construction were not compelling.

With respect to the finding that claims 8 and 10 of the ’850 patent and claims 1, 2, and 3 of the ’518 patent were invalid for indefiniteness, the Federal Circuit noted that while a claim directed to both a method and an apparatus may be indefinite, apparatus claims are not necessarily indefinite for using functional language. The Federal Circuit disagreed with the district court, finding the claims were simply apparatus claims with proper functional language, like HTC and MEC and UltimatePointer. The Federal Circuit said that like the claims in MEC, HTC, and UltimatePointer, the claims at issue merely claim that the system possesses the recited structure which is capable of performing the recited functions.

Further, the Federal Circuit distinguished IPXL Holdings and Katz, as the claims at issue do not claim activities performed by the user; they do not explicitly claim the user’s act of selection, but rather, claim the system’s capability to receive and respond to user selection.

Because these claims inform those skilled in the art about the scope of the invention with reasonable certainty, the Federal Circuit reversed the district court’s determination that claims 8 and 10 of the ’850 patent and claims 1, 2, and 3 of the ’518 patent are invalid as indefinite.