Federal Circuit Holds Use Of A Restrictive Term In An Earlier Application Does Not Apply In A Later Patent That Purposely Deletes The Restriction
On November 1, 2022, the United States Court of Appeals for the Federal Circuit (“CAFC”) issued an opinion reversing-in-part, vacating-in-part, and remanding a summary judgment decision by the United States District Court for the Southern District of California, Judge Cathy Ann Bencivengo, finding asserted claims from a family of related patents indefinite and thus invalid. Finjan LLC, Inc. v. ESET, LLC, No. 2021-2093 (Fed. Cir. Nov. 1, 2022). The CAFC held, inter alia, that the district court’s construction of the term “Downloadable,” appearing in all asserted claims, was improperly restricted to the narrowest of competing definitions provided in the patent family.
In 2017, apellant patentee asserted a family of patents directed to systems and methods for detecting computer viruses in a “Downloadable” through a security profile.
The “Downloadable” term is defined in a common parent provisional application as “an executable application program which is automatically downloaded from a source computer and run on the destination computer. Examples of Downloadables include applets designed for use in the Java™ distributing environment ….”
After conducting a Markman hearing, the district court issued an order construing the term “Downloadable” to mean “a small executable or interpretable application program which is downloaded from a source computer and run on a destination computer.” The district court’s construction was based (i) on a definition provided in non-asserted U.S. Patent No. 6,617,520, which patent issued from an early non-provisional application in the patent family that added the qualifier “small” to the “Downloadable” definition provided in the common parent provisional application, and (ii) on examples included in the various patents across the family tree.
Subsequently, on March 29, 2021, the district court granted apellee’s motion for summary judgment of invalidity, finding the asserted patents indefinite based on the word “small” as used in the court’s construction of “Downloadable.” Appellant patentee appealed both the construction of “Downloadable” as being restricted to “small … programs” and the finding of indefiniteness.
The CAFC concluded that the district court erred in construing “Downloadables” as “small … programs” based on the ’520 patent, even though that patent was incorporated in the subsequently issuing asserted patents, because the asserted patents also included, expressly or by incorporation, competing definitions of “Downloadables” that were not restricted to “small … programs.”
According to the CAFC, the “disclosures of related patents may inform the construction of claim terms common across patents, but it is erroneous to assume that the scope of the invention is the same such that disclaimers of scope necessarily apply across patents.” Consequently, ruled the CAFC, it was error for the district court to view the differing definitions throughout the patent family as competing and to determine that the asserted patents should be limited to the most restrictive definition in the family. To the contrary, observed the CAFC, the use of a restrictive term in an earlier application does not reinstate that term in a later patent that purposely deletes the term, even if the earlier patent is incorporated by reference.
Because the CAFC reversed the district court’s claim construction, it did not need separately to address the issue of indefiniteness, which hinged on the district court’s erroneous construction.