In re Power Integrations, Inc., No. 2017-1304, 2018 (Fed. Cir. Mar. 19, 2018) (Before Moore, Mayer, and Stoll, J.) (Opinion for the court, Mayer, J.)
The Court reversed a PTAB decision invalidating Power Integrations’ U.S. Patent No. 6,249,786 (“the patent”) as anticipated because the Board’s decision was based on an unreasonably broad claim construction.
The patent covers a circuit that reduces electronic magnetic interference by “jittering the switching frequency of a switched mode power supply.” At issue was the term “coupled,” which had been construed previously in a reexamination proceeding and in district court.
In 2014, the patent was asserted against Fairchild Semiconductor in the Delaware, where the court construed “coupled” to require two circuits to be connected in a manner “such that voltage, current or control signals pass from one to another” and that coupling is “present for the purposes of control.”
The PTO instituted ex parte reexamination in 2006, while the district court litigation was pending, and rejected the relevant claims as anticipated, which the Board affirmed. The Board’s construction of “coupled” merely required the “[components] functioning together” as “joined into a single circuit.” The Board rejected arguments that the references failed to disclose a “coupled” circuit as claimed, because “they disclose a ROM separating a counter from a digital to analog converter.” (The interjected ROM would control signals, not the coupled circuits.) The Board also rejected a similar argument that another reference failed to anticipate because it used an EPROM between the counter and the digital to analog converter.
In 2015, the Court vacated the Board’s rejection because the claim construction, using a generalist dictionary, “failed to provide a full and reasoned explanation of its decision.” On remand, the Board acknowledged the Court’s concern regarding “coupled,” but ultimately determined that consideration of the district court’s claim construction was “unwarranted.” It affirmed its rejection of the claims.
On its second review, the Court took issue with the PTO’s construction of “coupled.” While the “broadest reasonable interpretation” applies at the PTO, that interpretation must be consistent with the specification, and does not allow “unfettered license to interpret the words in a claim.” The Court pointed to several portions of the specification that support a narrower construction of “coupled”, noting that the patent “strives to eliminate unnecessary components and create a more compact circuit.”
The Court also rejected the Board’s reasoning that the specification failed to “proscribe or preclude” the Board’s construction. Instead, “a proper claim construction analysis endeavors to assign a meaning to a disputed claim term that corresponds with how the inventor describes his invention in the specification.” The Court adopted the construction applied by the district court, and found that “[i]n short, because the prior art relies on an intervening memory to adjust the control input, it does not disclose a counter which is ‘coupled’ to a digital to analog converter and ‘caus[es]’ it ‘to adjust the control input and to vary the switching frequency of the power supply.’”
The broadest reasonable interpretation of a claim term does not allow “unfettered license” to disregard “how the inventor describes his invention in the specification.”