“The district court construed the claims to not have a hierarchical structure and determined that defendants-cross-appellants did not infringe, and the CAFC agreed.”
Last week, the U.S. Court of Appeals for the Federal Circuit (CAFC) affirmed the United States District Court for the Northern District of California’s final judgment of noninfringement of SpeedTrack’s (Plaintiff-Appellant) patent U.S. Patent No. 5,544,360 (the ‘360 patent). SpeedTrack sued online retailers AMAZON.COM, BESTBUY.COM, LLC, OFFICEMAX, INC., MACY’S, INC., MACYS.COM, LLC and many others for infringement of its category-based filing system. The ultimate decision weighed on the district court’s construction of claims and whether or not the ‘360 patent had a hierarchical structure. The district court construed the claims to not have a hierarchical structure and determined that defendants-cross-appellants did not infringe. The CAFC, with Judge Prost writing for the court, agreed.
The ‘360 Patent Discloses a Non-Hierarchical Computer Filing System
The ‘360 patent discloses a “computer filing system for accessing files and data according to user-designated criteria.” ‘360 Patent Abstract. The patent explains that prior art systems emulate common physical filing systems where a document is stored in a file, itself within a file folder. According to the ‘360 patent, this system can become cumbersome when either the number of files becomes too large, or a file could logically be stored in multiple folders at the same time.
The prior art had solutions, but according to the ‘360 patent the previous solutions were clunky. The ‘360 patent discloses a method that uses “hybrid” folders, which “contain those files whose content overlaps more than one physical directory”. Claim 1 of the ’360 patent recites a three-step method. Firstly, a “category description table” containing “category descriptions” is created. The category descriptions have no hierarchical relationships with each other. Secondly, a “file information directory” is created as the category descriptions are associated with files. Finally, a “search filter” is created, which enables searching for files using their category descriptions.
In one embodiment, a user can find a file by clicking on a category description in a pick list (the category description table disclosed in Claim 1). After the first category description is selected, the pick list refines its list to only include category descriptions that would yield a file considering the first selection. This process can be repeated to narrow the selection down to the desired file or list of files.
District Court: Claim Construction Must be Read in Light of Construction During Previous Litigation
In September of 2009, SpeedTrack sued various retailers, including Amazon, BestBuy, OfficeMax, Macy’s, and many others, alleging infringement of the ‘360 patent. The district court hinged its opinion on the claim construction of the hierarchical limitation. It adopted SpeedTrack’s proposed construction—that the category descriptions do not have a predefined hierarchical relationship. The court considered disclaimers made during prosecution, as well as constructions presented in previous litigation. The court rejected Cross-Appellant’s proposed construction, which added a requirement that “[a] data field and its associated values have a predefined hierarchical relationship.” Upon SpeedTrack’s motion, which in part sought to “clarify the district court’s construction regarding prosecution-history disclaimer,” the court clarified “’Predefined’ means that a field is defined as a first step and a value associated with data files is entered into the field as a second step.” After clarification of the definitions, SpeedTrack stipulated to noninfringement because the accused products and services use a hierarchical field-and-value relationship, as defined in the Court’s modified construction. Upon the district court’s entrance of a final judgment for noninfringement, SpeedTrack timely appealed.
CAFC Agrees that Disclaimers Made During Prosecution Carry Over to Later Claim Construction
There was no dispute that Cross-Appellants do not infringe under the district court’s clarified construction. Therefore, the CAFC only needed to determine whether the construction was correct. They concluded that it was.
The words of a claim are generally given their plain and ordinary meaning as they’re interpreted by a person having ordinary skill in the art. The claims will also be read in view of the specification. An applicant can disclaim certain interpretations during the prosecution of the patent, narrowing the scope more than it would normally be interpreted. The CAFC reviews claims construction using a de novo standard.
SpeedTrack acknowledged that the ‘360 patent applicants added the hierarchical limitation during prosecution to overcome U.S. Patent No. 5,047,918 (“Schwartz”). The parties disagreed, however, as to the effect of its history on the claim scope; specifically, they contest whether the claims cover predefined hierarchical field-and-value relationships. The CAFC determined they do not.
In prosecution remarks, the ‘360 patent applicants distinguished their invention from Schwartz, “a system that ‘assigns user-definable attributes to . . . data files,’ where each attribute has ‘a user-defined name,’ such as ‘author,’ and where ‘a user may assign a value to the file attribute,’ such as ‘Smith[.]’” Unlike Smith, the applicant explained that their invention does not require the “2-part hierarchical relationship between fields or attributes, and associated values for such fields or attributes.” The applicants explained that the present invention covered a non-hierarchical filing system that allows for “free-form” reference from category descriptions to files without regard to “rigid definitions of distinct field containing values.” The CAFC noted that “[i]mportantly, there is also a ‘hierarchical’ relationship between values and fields. That is, each value MUST correspond to an associated field type.”
The applicants differentiated their invention from Schwartz by proposing a hypothetical. In this hypothetical, if the word “Language” was presented as a field, possible values could be “French” or “English”. From this structure, the value “French” MUST refer to language, the field that it is associated with. It cannot correspond to other field characteristics “such as food type, culture, travel, etc.” In the ‘360 patent, “French” could correspond to a multitude of these pre-defined characteristics without needing to belong to a rigid field. The invention is described by the applicant as “fieldless,” instead the category descriptions are directly applied to the file.
CAFC Determines that Prosecution History Disclaimers Can Be Applied to Litigation
“Prosecution disclaimer can arise from both claim amendments and arguments,” wrote the CAFC, quoting Tech. Props. Ltd. V. Huawei Tech. Co., 849 F.3d 1249, 1357 (Fed. Circ. 2017). The court agreed with the district court that both were presented in this case. The applicant definitively argued that Schwartz’s hierarchical relationship between fields and values fell outside of the scope of the amended claims. Therefore, the claims excluded predefined field-and-value relationships as explained by the district court. SpeedTrack contested this interpretation. SpeedTrack stated that the applicants indicated merely that the “category descriptions” of the ‘360 patent are not the fields of Schwartz and that the hierarchical limitation precluded predefined hierarchical relationships only among category descriptions. The CAFC was unpersuaded by this argument because the applicant “repeatedly highlighted predefined hierarchical field-and-value relationships as a difference between Schwartz and the ‘360 patent.”
Cross-Appellants also pointed to SpeedTrack’s earlier contradicting statements in other litigation. In a motion, SpeedTrack stated that:
This amendment further distinguished the “category descriptions” from “fields”/“attributes,” which, as the inventors explained, have a “hierarchical” relationship between fields and their values[.]
SpeedTrack contested that the litigation statements “are not inventors’ prosecution statements” and therefore did not demonstrate prosecution-history disclaimer. Although the CAFC ultimately did not decide the case on this issue, they noted that the ultimate goal of prosecution history disclaimer is to ensure that claims are not read one way to gain allowance and read a different way against accused infringers.
For the reasons above, the CAFC held the district court’s claim constructions were correct and therefore affirmed the final judgment of noninfringement.