Recently, the U.S. Court of Appeals for the Federal Circuit issued an opinion in SpeedTrack, Inc. v. Amazon.com, Inc., No. 20-1573 (June 3, 2021), affirming the Northern District of California’s reliance on prosecution history disclaimer in construing claims of SpeedTrack’s U.S. Patent No. 5,544,360.
The ’360 patent discloses a computer filing system and method that uses “hybrid” file folders with overlapping content. During prosecution, the applicant amended the patent claims to include the following limitation: “category descriptions having no predefined hierarchical relationship with such list or each other.” The applicant argued that the amended claims distinguished the prior art Schwartz reference because Schwartz disclosed a “hierarchical” field and value system (such as a “Language” field with a “French” category).
After the ’360 patent issued, SpeedTrack sued Amazon for infringement. In the litigation, the district court held that category descriptions based on hierarchical relationships were disclaimed during prosecution and construed the claims, accordingly, to exclude predefined hierarchical field-and-value relationships. Based on the district court’s claim construction, SpeedTrack stipulated to judgment of noninfringement. Judgment was entered, and SpeedTrack appealed.
The Federal Circuit affirmed. The Court rejected SpeedTrack’s argument that the prosecution history reflected only disavowal of predefined hierarchical relationships among category descriptions. The Court explained that applicant’s arguments “repeatedly highlighted predefined hierarchical field-and-value relationships” as features of the prior art from which the ’360 patent’s claims were distinct. Indeed, the applicant had specifically argued during prosecution that the claims of the ’360 patent were directed to “a non-hierarchical filing system that allows essentially ‘free-form’ association of category descriptions to files without regard to rigid definitions of distinct fields containing values.” The Court also rejected SpeedTrack’s argument that there was no clear and unmistakable disavowal of claim scope because the applicant had also made arguments distinguishing the prior art on other grounds. The Court explained that “[a]n applicant’s argument that a prior art reference is distinguishable on a particular ground can serve as a disclaimer of claim scope even if the applicant distinguishes the reference on other grounds as well.” Finally, the Court held that prior claim constructions in other litigation and in reexamination did not undermine the district court’s holding in the present case because these prior constructions involved stipulations or otherwise did not address the issue now presented.
This blog post was co-authored by Dan McDonald and Marra Clay.