Poly-America, L.P. v. API Industries, Inc., 2016-1200, 2016 U.S. App. LEXIS 18486 (Fed. Cir. Oct. 14, 2016) (Before Prost, Hughes, and Reyna, C.J.) (Opinion for the court, Reyna, C.J.)
Poly-America sued API Industries, Inc. (API) for infringement of a patent for a trash bag with “short seals” at its upper corners that extend inwardly to narrow the bag’s upper opening. On appeal, the Federal Circuit analyzed the district court’s claim construction de novo and considered Poly-America’s arguments that the district court imported limitations from embodiments in the specification, misread the prosecution history, and ignored principles of claim differentiation.
The Court focused on whether the inventor had disclaimed trash bags with short seals that do not extend inwardly to narrow the upper opening width. The Court reiterated that the standard for such disavowal is exacting, requiring clear and unequivocal evidence that the claimed invention does or does not include a particular feature – although a disavowal need not be explicit.
Disavowal can occur when the specification plainly describes “the present invention” as having that feature. Here, the specification states that an important characteristic of the present invention is a “reduction in upper width … resulting from the extended short seals.” Disavowal can also occur when the specification distinguishes or disparages prior art based on a specified feature. The specification did that here, by stating that prior art bags are difficult to secure over trash receptacle lips and explaining how the described short seals solve this problem.
Finally, the Court considered whether the “inwardly extending” claim construction of “short seals” would render a dependent claim redundant or would implicate the principles of claim differentiation. The Court concluded that construing short seals to require inward extension would provide for a distance less than 100 percent of the bag width. This did not make the more specific range of the dependent claim redundant. Claim differentiation furthermore does not serve to broaden claims beyond their meaning in light of the patent as a whole, and it cannot override clear statements of claim scope found the specification and prosecution history.
Accordingly, the Court held that the patentee had clearly and unequivocally disavowed claims comprising short seals that do not extend inwardly, and it affirmed the district court’s claim construction.
Claim differentiation does not broaden claims beyond their meaning in light of the patent as a whole, and cannot override clear statements of claim scope found the specification and prosecution history.