A Preamble That Saves May Be a Preamble That Limits
Before Reyna, Hughes, and Stoll. Appeal from the United States District Court for the District of Delaware.
Summary: A patentee that relies on language in the preamble to successfully argue that its claims are directed to patent eligible subject matter cannot later assert that this preamble language has no limiting effect for the purposes of determining infringement.
Data Engine Technologies (DET) sued Google in the District Court of Delaware for infringement of a patent owned by DET. The patent at issue described the use of tabbed navigation of pages in three-dimensional spreadsheets. Google asserted that the claims were invalid under 35 U.S.C. § 101. The District Court agreed and found that the claims were directed to the abstract idea of using notebook-style tabs to label and navigate spreadsheets. DET appealed to the Federal Circuit, relying on the preamble of the claims to argue that the innovation of the patent was in providing a user-friendly navigation specifically in the context of three-dimensional spreadsheet applications. The Federal Circuit agreed with DET and remanded for further proceedings.
After remand, Google sought to reopen claim construction and asked the District Court to construe the preamble of the claims as limiting. The District Court agreed and found that Google did not infringe DET’s patent because Google’s allegedly infringing spreadsheet application did not provide three-dimensional spreadsheets. DET appealed to the Federal Circuit, which affirmed, stating “where … a patentee relies on language found in the preamble to successfully argue that its claims are directed to eligible subject matter, it cannot later assert that the preamble term has no patentable weight for purposes of showing infringement.”
Editor: Paul Stewart