District Court’s Failure to Consider Unrebutted Expert Testimony and Surrounding Claim Context Fatal to Means-Plus-Function Analysis

In Dyfan, LLC v. Target Corp., No. 21-1725 (Fed. Cir. Mar. 24, 2022), the Federal Circuit reversed the district court’s determination that certain claim limitations were in means-plus-function format, and its resulting determination that the claims were indefinite because the specification failed to disclose sufficient corresponding structure.

Dyfan asserted two patents against Target describing systems for delivering messages to users based on their locations. The asserted claims included several “code”/”application” terms and “system” terms. The district court held the “code”/”application” terms were means-plus-function terms and assigned a “special purpose computer function” as their corresponding structure. The court nevertheless held that the claims were indefinite because the specification failed to recite an algorithm for that “special purpose computer.” The court also found the “system” terms were means-plus-function terms because they recited purely functional language, and it was “unclear which of the recited components perform[ed] the specified function.” The court held the relevant claims were also indefinite for lack of corresponding structure in the specification.

The Federal Circuit reversed and held neither the “code”/”application” terms nor the “system” terms were means-plus-function terms. For the “code”/”application” terms, the Federal Circuit found the district court erred by ignoring unrebutted expert testimony showing that the skilled artisan would have understood these terms to be structural. In particular, the expert opined that “application” is commonly understood to mean a “computer program intended to provide some service to a user,” and developers could have selected off-the-shelf software to perform specific services/functions. The expert also opined that “code,” when coupled with language describing its operation, connotes structure, i.e., “a bunch of software instructions.” For the “system” terms, the Federal Circuit acknowledged, “in a vacuum, the term ‘system’ may well be a nonce term.” But in this case, the claim language defined the “system” to include specific structure (including a building having a first broadcast short-range communications unit, a second broadcast short-range communications unit, code executed by at least one mobile device, at least one server), bringing it beyond the purview of means-plus-function claiming.