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Justin E. Gray

IP Litigation Attorney at Foley & Lardner LLP

Former Adjunct Professor at Northwestern University School of Law

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Federal Circuit Affirms Construction That Did Not Read Terms Out of the Claims and Covered the Preferred Embodiment

SynQor, Inc. v. Artesyn Technologies, Inc. (Fed. Cir. Mar. 13, 2013)

In this case, the Federal Circuit affirmed the district court's claim construction of "isolation" to be limited to "an input and an output of a particular stage, component, or circuit."  The patents at issue related to high-efficiency DC-DC power converter systems used to power circuitry in large computer systems and telecommunications and data communication equipment.

The district court construed the claim terms "isolation", "isolating", and "isolated" to mean "the absence of an electric path permitting the flow of DC current (other than a de minimus amount) between an input and an output of a particular stage, component, or circuit."  The court went on to grant partial summary judgment of infringement.

On appeal, the defendants argued the the construction should require isolation "between two points" rather than "between an input and an output of a particular stage, component, or circuit", also asserting that "consumers connect the input and output of the claimed system to a common ground such that the system is not isolated."

The Federal Circuit ultimately agreed with the district court's construction, explaining that the term "isolation" was used in the claims "as an adjective describing a stage or converter with the power converter system", citing examples in numerous claims.  The court found that "requiring 'isolation' between every two points in the system would read the terms 'stage' or 'convertor' out of the claims."

The court also stated that while the patent figures "show an isolation stage that has no electrical connection between its input and output" they do not show "the entire power converter system."  Further, the defendants' expert admitted that construing the claims in defendants' fashion would prevent the claims from encompassing the preferred embodiment.

The court held that the district court correctly construed "isolation" and affirmed the grant of partial summary judgment of infringement.