No Disclaimer, No Problem – Terms Limited by Consistent Statements

By on April 2, 2020

In an appeal from the Patent Trial and Appeal Board (PTAB), the US Court of Appeals for the Federal Circuit found claim construction error and reversed the PTAB’s finding that all instituted claims were unpatentable. Personalized Media Commc’ns, LLC v. Apple Inc., Case No. 18-1936 (Fed. Cir. Mar. 13, 2020) (Stoll, J.).

The dispute began when Apple filed a petition for inter partes review (IPR) challenging certain claims of a patent owned by Personalized Media Communications (PMC). The construction of the phrase “an encrypted digital information transmission including encrypted information” was of particular import in the ensuing IPR proceeding. Under the broadest reasonable interpretation standard, PMC argued that the phrase was limited to digital transmissions, whereas Apple argued that the phrase “may also include transmissions with information that is not encrypted or digital.” The PTAB adopted Apple’s construction and found the claims invalid. PMC appealed.

Although PMC presented multiple challenges on appeal, the Federal Circuit focused on the construction of the term “an encrypted digital information transmission including encrypted information.” The Court found that the claim language was not dispositive on whether the claims were limited to digital transmissions. Because both PMC’s and the PTAB’s constructions were possible in view of the claim language, the Court looked to the specification.

PMC focused on three specification sections that distinguished digital processes from analog processes in a way that limited the claim term. While the Federal Circuit agreed that the cited sections were consistent with PMC’s construction, it found that the specification fell short of limiting the claim term “to all-digital processes.”

Apple similarly argued that the specification supported its construction, referring to the portions of the specification the PTAB relied on in support of its claim construction. Specifically, the PTAB relied on an exemplary embodiment in the specification that included analog features, meaning the term at issue was not limited to merely digital transmissions.

On that argument, the Federal Circuit found that just as an embodiment is not read into the claims when the claims are broader than the embodiment, an embodiment is not read into the claims when the claims are narrower than the embodiment. Concluding that the specification did not support or refute either claim construction, the Court next looked to the prosecution history.

PMC specifically argued that three parts of the prosecution history supported its construction. In the first two sections, the applicant argued that the claims were patentable because they required a digital process that was not disclosed in the prior art. In the third section, the applicant amended the claims to clarify its position that “encryption requires a digital signal.” Although these sections did not arise to a disclaimer, the Federal Circuit found that the statements nevertheless informed the claim construction.

The Federal Circuit explained that an applicant’s repeated and consistent remarks during prosecution can define a claim term even if such statements do not rise to the level of unmistakable disavowal. Accordingly, the Court concluded that the claims were limited to digital transmissions and reversed the PTAB’s finding of invalidity for the terms containing the disputed phrase.

Practice Note: Even if one or more specific statements in the prosecution history do not constitute a classic prosecution history disclaimer, such statements taken in the context of all intrinsic evidence can still define a claim term, particularly when the statements are consistent throughout the prosecution history.