In the second appeal to the US Court of Appeals for the Federal Circuit, the preamble term “three-dimensional spreadsheet” was found to be a limitation in the context of claims directed to organizing and presenting information in electronic spreadsheets based on prosecution disclaimer and arguments made in the first appeal. Data Engine Techs, LLC v. Google LLC, (DET II), Case No. 21-1050 (Fed. Cir. Aug. 26, 2021) (Stoll, J.)

In the first appeal (DET I), the Federal Circuit found that DET’s representative claim was “directed to more than a generic or abstract idea as it claims a particular manner of navigating three-dimensional spreadsheets,” improving on electronic spreadsheet functionality and, therefore, directed to patent-eligible subject matter. The Court reversed and remanded. On remand, Google requested that the district court reopen claim construction and construe the preamble term “three-dimensional spreadsheet” in the representative claim.

The district court found the preamble to be limiting and construed “three-dimensional spreadsheet” to mean a “spreadsheet that defines a mathematical relation among cells on different spreadsheet pages, such that cells are arranged in a 3-D grid.” The district court went on to grant Google’s motion for summary judgment of noninfringement as there was no dispute that the accused product (Google Sheets) did not meet the “three-dimensional spreadsheet” limitation under the court’s construction. DET appealed.

Applying de novo review to the claim construction issue presented, the Federal Circuit noted that in DET I, its conclusion that the asserted claims were directed to improvements in three-dimensional spreadsheets ascribed patentable weight to the preamble term “three-dimensional spreadsheet.” The dispute related to whether the claim requires “a mathematical relation among cells on different spreadsheet pages,” as required by the district court’s construction.

The Federal Circuit found that neither the claims themselves nor the specification provided guidance in construing “three-dimensional spreadsheet.” Turning to the prosecution history, the Court noted that during prosecution, the applicants provided an explicit definition of a “true” three-dimensional spreadsheet and distinguished prior art under this definition. Indeed, as the Court noted, its ruling in DET I expressly relied on that definition from the prosecution history in determining that the claims required a three-dimensional spreadsheet that “defines a “three-dimensional spreadsheet” in support of patent eligibility. Thus, the Court concluded that the preamble term was limiting.

In the present appeal, DET contended that the prosecution history passage defining a three-dimensional spreadsheet did not rise to the level of “clear and unmistakable” disclaimer when read in context of the spreadsheet (Lotus 1-2-3) it was distinguishing. The Federal Circuit rejected the argument noting, “DET cannot escape the import of its statements to the Patent Office by suggesting they were not needed to overcome the Examiner’s rejection. Consistent with the public notice function of the prosecution history, the public is entitled to rely on these statements as defining the scope of the claims.” In rejecting DET’s arguments, the Court again cited to the imagery of twisting claims, “like ‘a nose of wax,’ ‘one way to avoid [invalidity] and another to find infringement.’”