In Patent Cases, What You Say Can Come Back to Haunt You

In a patent infringement action involving a long list of big-name defendants, a plaintiff learned that what you say to the Patent Office during the patent prosecution process can come back to haunt you in court when you try to enforce your patent rights – with fatal consequences.

SpeedTrack owns U.S. Patent No. 5,544,360 (“the ’360 patent”), which discloses a “computer filing system for accessing files and data according to user-designated criteria.” As the Federal Circuit noted:

The patent explains that prior art systems “employ a hierarchical filing structure.” Id. at col. 1 ll. 28–29. Those systems “emulate[] commonly[ ]used paper filing systems” in that they “organize[] data into files (analogous to papers in a paper filing system) and directories (analogous to file folders and hanging files).”

There is, of course, nothing “novel” about commonly used paper filing systems, even when a computer is used to emulate them.

To overcome a prior art reference that leveraged hierarchical field-and-value relationships. SpeedTrack added a limitation that “the category descriptions hav[e] no predefined hierarchical relationship with such list or each other” during prosecution of the patent.

In 2009, SpeedTrack sued various retail website operators, including Amazon, Dell, and HP, alleging patent infringement. The district court adopted SpeedTrack’s proposed construction:

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.

The district court concluded that the patent prosecution history “demonstrate[d] clear and unambiguous disavowal of category descriptions based on hierarchical field-and-value systems.” The court then issued a second claim construction order explicitly disclaiming “predefined hierarchical field-and-value relationships” from the scope of “category descriptions” and clarifying that

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.

The court entered final judgement of non-infringement, and SpeedTrack appealed.

The Federal Circuit noted that it was undisputed that there was no infringement under the district court’s clarified construction. Thus, the only issue was whether that construction was correct. The court concluded that it was.

The court pointed out that

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.’

That is just what SpeedTrack was trying in this case, the court said.

Thus, the court affirmed the district court’s final judgement of non-infringement.

Categories: Patents