Addressing both the circumstances that lead to a claim limitation invoking a means-plus-function construction and indefiniteness issues for means-plus-function claims, the US Court of Appeals for the Federal Circuit affirmed the district court’s finding that the term “symbol generator” invoked means-plus-function claiming and was indefinite because the specification failed to disclose a corresponding algorithm for performing the claimed function. Advanced Ground Info. Sys., Inc. v. Life360, Inc., Case No. 15-1732 (Fed Cir., July 28, 2016) (Wallach, J).

Life360 is a startup company and creator of a Life360 mobile app that allows users to view each other on a map, communicate and receive alerts when other users arrive at designated locations. Advanced Ground Information Systems, Inc., (AGIS) filed a complaint in district court alleging that Life360’s mobile app infringed several claims of its patents. In response, Life360 alleged that the terms “symbol generator” and “CPU software” in the asserted claims invoke means-plus-function claiming under 35 USC § 112, ¶ 6 and were indefinite for failure to disclose adequate structure. After the district court agreed with Life360, AGIS appealed to the Federal Circuit.

The Federal Circuit first analyzed whether the term “symbol generator” invoked § 112, ¶ 6, noting that it need not independently address the term “CPU software” if it found the term “symbol generator” indefinite. In this case, although the asserted claims do not include the word “means,” the Federal Circuit nevertheless affirmed the district court’s finding that AGIS intended to invoke § 112, ¶ 6. According to the Federal Circuit, the combination of the terms “symbol” and “generator,” as used in the context of the relevant claim language, simply describes the function being performed—the generation of symbols. The term “symbol generator” does not, by itself, identify a structure by its function, nor do the asserted claims suggest that the term connotes a definite structure. 

Next, the Federal Circuit analyzed whether the specifications adequately describe what is meant by the term “symbol generator” in the claims. In this case, the patents-in-suit do not describe this component other than to specify the medium through which the symbols are generated. The Court found the specifications’ description insufficient, explaining that simply disclosing a general-purpose computer as the structure designed to perform the necessary function is insufficient to overcome an indefiniteness challenge. According to the Court, the specifications should have disclosed an algorithm for the claimed “symbol generator.” Finding that the specifications failed to disclose the required operative algorithm for this term, the Federal Circuit affirmed the district court’s conclusion that the claims were indefinite.