By Courtney Seams, GW Law, J.D. 2022
The U.S. Court of Appeals for the Federal Circuit recently reversed a District Court’s claim construction opinion relating to Nintendo’s alleged infringement of Genuine Enabling’s patent on data streams. Genuine alleges that Nintendo’s Wii remote, Wii nunchuck, Switch Joy-Con Controller and Switch Pro controller are infringing its data stream patent that describes a method and device for streamlining and combining various data streams to conserve computer resources. In front of the District Court, Genuine and Nintendo disputed the breadth of Genuine’s patent, specifically disagreeing over what range of signals are covered by the patent’s term “input signal.”
Nintendo alleged that Genuine’s patent only covered signals above 500 Hertz. Nintendo’s argument was based on the patent prosecution of the Genuine patent, during which the inventor specifically disclaimed any signals that were described in a piece of prior art. Nintendo, using an expert, argued that a person of ordinary skill in the art would have known that the piece of prior art described frequencies of at least 500 Hertz, so when the inventor specifically disclaimed the frequencies described by the prior art, the inventor disclaimed only the frequencies of 500 Hertz and above.
Genuine, however, argued that the inventor only disclaimed those frequencies that were not within the frequency range able to be heard by humans and, thus, only disclaimed those frequencies lower than 20 Hertz or greater than 20,000 Hertz. Thus, Genuine argued that the meaning of “input signal” in the patent should be given a broader construction. The District Court, however, agreed with Nintendo granting summary judgment for Nintendo and its construction of the term “input signal,” finding that the Genuine patent only included signals greater than 500 Hertz.
The Federal Circuit disagreed with the District Court finding that the lower court relied too heavily on the extrinsic record in construing the claim. The extrinsic record of a patent includes expert opinions and external literature, while the internal record of a patent includes the patent prosecution history and the patent claims and specification. According to the Federal Circuit, the extrinsic record is less reliable for claim construction than the internal record. Extrinsic evidence should only be relied on to understand the patent and not change or contradict its terms. Therefore, expert testimony should not be used by the court to depart significantly from what is mentioned in the internal history of the patent. The Federal Circuit found that the District Court violated this rule by relying on Nintendo’s expert’s opinion to define “input signal” in a way that disagreed with the internal record of the patent. During the prosecution of Genuine’s patent, there was not a specific range of frequencies disclaimed, only those frequencies outside the range of human hearing were disclaimed. Thus, the District Court’s decision that Genuine had disclaimed only those frequencies above 500 Hertz was not contained anywhere in the internal record and was purely based on the opinion of Nintendo’s expert.
As a result, the Federal Circuit found that the District Court erred in constructing the claim and that “input signal” includes signals whose frequencies are within the audio spectrum for human hearing, which includes some frequencies lower than 500 Hertz.
The Federal Circuit’s strong stance on claim interpretation will likely affect future claim construction decisions and future litigants can expect that extrinsic evidence will not be the focus of the court in defining claims. Patent owners will need to ensure that their preferred definition of the claim can be supported by the internal record of the patent going forwards.
