DOCTRINE OF PROSECUTION DISCLAIMER ENSURES THAT CLAIMS ARE NOT CONSTRUED ONE WAY TO GET ALLOWANCE AND IN A DIFFERENT WAY TO AGAINST ACCUSED INFRINGERS
| July 8, 2021
SpeedTrack, Inc. v. Amazon.com, Inc. et al.
Decided on June 3, 2021
Prost (author), Bryson, and Reyna
Summary:
The Federal Circuit affirmed the district court’s claim construction orders regarding the hierarchical limitations recited in the SpeedTrack’s ’360 patent based on Applicants’ arguments and claim amendments made during the prosecution of the ’360 patent.
Details:
The ’360 patent
SpeedTrack owns U.S. Patent No. 5,544,360 (“the ’360 patent), which is directed to providing “a computer filing system for accessing files and data according to user-designated criteria.” The ’360 patent discusses that prior-art systems “employ a hierarchical filing structure” which could be very cumbersome when the number of files are large or file categories are not well-defined. In addition, the ’360 patent discusses that some prior-art systems are subject to errors when search queries are mistyped and restricted by the field of each data element and the contents of each field.
However, the ’360 patent discloses a method that uses “hybrid” folders, which “contain those files whose content overlaps more than one physical directory,” for providing freedom from the restrictions caused by hierarchical and other computer filing systems.
Representative claim 1 recites a three-step method: (1) creating a category description table containing category descriptions (having no predefined hierarchical relationship with such list or each other); (2) creating a file information directory as the category descriptions are associated with files; and (3) creating a search filter for searching for files using their associated category descriptions.
1. A method for accessing files in a data storage system of a computer system having means for reading and writing data from the data storage system, displaying information, and accepting user input, the method comprising the steps of:
(a) initially creating in the computer system a category description table containing a plurality of category descriptions, each category description comprising a descriptive name, the category descriptions having no predefined hierarchical relationship with such list or each other;
(b) thereafter creating in the computer system a file information directory comprising at least one entry corresponding to a file on the data storage system, each entry comprising at least a unique file identifier for the corresponding file, and a set of category descriptions selected from the category description table; and
(c) thereafter creating in the computer system a search filter comprising a set of category descriptions, wherein for each category description in the search filter there is guaranteed to be at least one entry in the file information directory having a set of category descriptions matching the set of category descriptions of the search filter.
District Court
In September of 2009, SpeedTrack sued retail website operations for infringement of the ’360 patent. The Northern District construed the hierarchical limitation with the below construction (relied in part on disclaimers made during prosecution):
The category descriptions have no predefined hierarchical relationship. A hierarchical relationship is a relationship that pertains to hierarchy. A hierarchy is a structure in which components are ranked into levels of subordination; each component has zero, one, or more subordinates; and no component has more than one superordinate component.
After that, SpeedTrack moved to clarify the district court’s construction regarding prosecution-history disclaimer.
Subsequently, the district court issued a second claim construction order by adding the following clarification in its first order:
Category descriptions based on predefined hierarchical field-and-value relationships are disclaimed. “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. “Hierarchical relationship” has the meaning stated above. A field and value are ranked into levels of subordination if the field is a higher-order description that restricts the possible meaning of the value, such that the value must refer to the field. To be hierarchical, each field must have zero, one, or more associated values, and each value must have at most one associated field.
In order to support its second claim construction order, the district court analyzed SpeedTrack’s prosecution statements (for their clear disavowal of category descriptions based on hierarchical field-and-value relationships).
The Federal Circuit
The CAFC handled the issue of claim construction.
SpeedTrack acknowledged that the hierarchical limitation was added during the prosecution of the ’360 patent to overcome the Schwartz reference.
During the prosecution, Applicants distinguished their invention from Schwartz by arguing that “unlike prior art hierarchical filing systems, the present invention does not require the 2-part hierarchical relationship between fields or attributes, and associated values for such fields or attributes.”
In addition, Applicants argued that “the present invention is 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.”
Finally, Applicants argued that “this distinction has been clarified in the claims as amended by the addition of the following language in all of the claims: ‘each category description comprising a descriptive name, the category descriptions having no predefined hierarchical relationships with such list or each other.’”).
The CAFC agreed with the district court’s assessment that predefined field-and-value relationships are excluded from the claims.
The CAFC disagreed with SpeedTrack’s argument that the “category descriptions” of the ’360 patent are not the fields of Schwartz and that the hierarchical limitation precludes predefined hierarchical relationships only among category descriptions.
SpeedTrack argued that Applicants distinguished Schwartz on other grounds. However, the CAFC did not agree with this argument.
In addition, the CAFC noted that SpeedTrack’s position contradicts its other litigation statements. “Ultimately, the doctrine of prosecution disclaimer ensures that claims are not ‘construed one way in order to obtain their allowance and in a different way against accused infringers.’” Aylus Networks, Inc. v. Apple Inc., 856 F.3d 1353, 1360 (Fed. Cir. 2017) (quoting Southwall Techs., Inc. v. Cardinal IG Co., 54 F.3d 1570, 1576 (Fed. Cir. 1995)).
Finally, the CAFC noted that both of the first and second construction orders acknowledged the disclaimer.
Therefore, the CAFC affirmed the district court’s final judgement of noninfringement.
Takeaway:
- Applicants need to be careful about claim amendments and arguments made during the prosecution of their patents.
- Litigation statements, while not inventors’ prosecution statements and do not demonstrate prosecution-history disclaimer, can strengthen the court’s reasonings on the prosecution history.
