Federal Circuit Clarifies Means-Plus-Function LimitationsJune 6, 2018

On June 1st, in Zeroclick, LLC v. Apple Inc, the United States Court of Appeals for the Federal Circuit (CAFC) vacated and remanded a district court decision that several patent claims asserted against Apple Inc. were invalid. The district court held that the claims contained means-plus-function limitations and that the specifications did not disclose sufficient structure.

The patent claims in question concern the ability of a graphical user interface to read a certain finger movement made by a user on a touch-screen as a mouse click and then perform a task. An example of this is the swipe method used to unlock many smartphones.

The CAFC found that the district court failed to address the proper question to determine whether a term is a means-plus-function limitation under 35 U.S.C. § 112(f). The CAFC asserted that the proper question is “whether the words of the claim are understood by persons of ordinary skill in the art to have a sufficiently definite meaning as the name for structure”. Further, the CAFC held that since the claims in question did not use the word “means,” there is a rebuttable presumption against terms being characterized as means-plus-function limitations. The district court failed to address this presumption.

The CAFC also found that the district court interpreted certain terms as nonce words, meaning that they can essentially be substituted for the word “means”, and, therefore, held that the terms were means-plus-function limitations under § 112(f). The CAFC found that the district court erred for three reasons:

  1. Terms should not be considered means-plus-function limitations simply because they use functional language.
  2. The district court effectively interpreted certain terms as generic when a person of ordinary skill in the art could reasonably classify them as specific references to items existing in prior art.
  3. The district court made no findings that the terms it treated as nonce words are ordinarily treated as such.

The CAFC clarified that the proper question to determine whether claims recite means-plus-function limitations is whether a person of ordinary skill in the art would classify the words in the claim as having a definite meaning as the name for a structure. Further, the CAFC reiterated the presumption against a term being means-plus-function limitation if the word “means” is not used.

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