Last week, the U.S. Court of Appeals for the Federal Circuit issued an order in Finjan LLC v. Eset LLC, et. al. No. 21-2093 (Nov. 1, 2022), reversing and remanding the district court’s claim construction for the term “Downloadable” and vacating the grant of summary judgment of invalidity.
Finjan’s patents concern methods and systems for detecting computer viruses in a “Downloadable” through a security profile. Two of the asserted patents, U.S. Patents Nos. 6,154,844 and 6,804,780, define “Downloadable” as “an executable application program, which is downloaded from a source computer and run on the destination computer.” But these patents also incorporate by reference an earlier, non-asserted patent, which defined “Downloadable” as “a small executable or interpretable application program which is downloaded from a source computer.” The three remaining asserted patents do not offer in their text a definition of “Downloadable”, but instead incorporate by reference multiple patents that provide these two different definitions of “Downloadable.”
The district court read these the two definitions of “Downloadable” as competing, and gave “Downloadable” its narrowest construction: “a small executable or interpretable application program which is downloaded from a source computer and run on a destination computer.” Based on this construction, the court granted Defendant ESET’s motion for summary judgment that the asserted patents were indefinite because it was unclear what “small” entailed. Finjan appealed.
On appeal, the Federal Circuit held the district court erred by reading the restrictive term “small” into the definition of a “Downloadable.” The Court explained that, although patents incorporated by reference are part of the host patents as if they had been included explicitly, “incorporation by reference does not convert the invention of the incorporated patent into the invention of the host patent.” The Court concluded it was improper to restore the word “small” into the definition of “Downloadable”, in part because the subsequent patents’ definitions of “Downloadable” deleted the term “small”. The Court further concluded that the context of the asserted patents confirmed the claimed invention was not restricted to “small” Downloadables (i.e. applets). Having concluded that the district court applied an incorrect claim construction to the claim term “Downloadable”, the Court vacated the district court’s judgment of invalidity due to indefiniteness and remanded for further proceedings.