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Circuitry Components May Be “Coupled” Without Existing Entirely Outside of One Another

July 06, 2012

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Last Month at the Federal Circuit - August 2012

Judges: Rader, Newman (author), Linn

[Appealed from: ITC]

In General Electric Co. v. International Trade Commission, No. 10-1223 (Fed. Cir. July 6, 2012), the Federal Circuit overturned a portion of an ITC decision finding that General Electric Company (“GE”) did not prove a violation under Tariff Act section 337. Specifically, the Federal Circuit (1) vacated the ITC’s ruling with respect to the first patent-at-issue because it had since expired; (2) affirmed the ITC’s ruling that the accused products do not violate section 337 with respect to the second patent-at-issue; and (3) reversed the ITC’s ruling that there is no domestic industry corresponding to the third patent-at-issue, remanding the case for further proceedings on the third patent.

The technology-at-issue relates to wind turbines. The asserted patents—U.S. Patent Nos. 5,083,039 (“the ’039 patent”); 7,321,221 (“the ’221 patent”); and 6,921,985 (“the ’985 patent”)—are directed to
wind-turbine generators and their interaction with the utility grid. In particular, the ’039 patent relates to control systems that allow variable-speed wind turbines to output the fixed-frequency alternating current required by power grids. The ’221 patent relates to a protective circuit called a “crowbar circuit,” which decouples particular components of the turbine when grid voltage varies, thereby protecting the circuitry of the wind turbine. The ’985 patent is directed to circuitry that allows wind turbines to remain connected to the grid during low-voltage events.

GE initiated an ITC investigation against Mitsubishi Heavy Industries, Ltd. and Mitsubishi Power Systems Americas, Inc. (collectively “Mitsubishi”), alleging that Mitsubishi’s wind turbines infringed the three asserted GE patents. In an Initial Determination, the ALJ held that the imported Mitsubishi turbines violated section 337, and held the asserted patents valid and infringed. Both parties requested review by the ITC. The ITC held by Final Determination that the ’039 and ’221 patents are not infringed, the ’039 patent is not invalid, and that the domestic industry requirement is not met as to any of the patents. Accordingly, the ITC found no violation of section 337. GE appealed this decision to the Federal Circuit.

The Federal Circuit first noted that the ’039 patent had expired after the ITC’s decision was appealed, and dismissed that portion of the appeal as moot.

With respect to the ’221 patent, the issue of infringement revolved around the construction of the term “predetermined value” in the context of “the currents generated in the rotor windings.” The parties disagreed over whether the term “predetermined value” includes not only a value of current, but also a predetermined period of time. The Court agreed with the ITC that the patentee described the invention as the resumption of current feed after the current is restored to the predetermined value, not after a fixed period of time. Because the Mitsubishi wind turbines use a predetermined period of time rather than a predetermined current value, the Court found that the ’221 patent is not infringed, affirming the ITC’s holding.

Turning to the ’985 patent, the Court addressed the construction of the claimed “circuit . . . to shunt current from the inverter and generator rotor.” The issue of claim construction was whether the asserted claim required the circuit that shunts current to be located entirely outside of the inverter, or whether it could be within the inverter. The Court disagreed with the ITC, holding that the function of the shunt circuit does not depend on whether the shunt circuit is entirely outside of the inverter, and that the ’985 patent specification does not require separation of the inverter and the shunt circuit. The fact that the claim recites the circuit “coupled” to the inverter was not persuasive, as the term “coupled” generically describes a connection and does not require one component to be entirely outside of the other.

The Court found that the asserted claim, correctly construed, covers GE’s domestic industry turbines, even though GE’s domestic industry turbines use a shunt circuit that is not separate from the inverter. The Court rejected the argument that the GE turbines embody a modification of the circuitry system in the ’985 patent that is separately patented in a different GE patent. In addressing this argument, the Court stated that “[t]he domestic industry requirement is not negated if the technology as employed in the domestic industry has been modified from its form when the patent was obtained.” Slip op.
at 21. Accordingly, the Court remanded for further proceedings with respect to the ’985 patent.

The Court’s opinion replaced an earlier panel decision in the appeal, issued on February 29, 2012.
The replacement opinion omitted a portion of the February decision that criticized the ITC for addressing only one dispositive issue with respect to the ’985 patent and reserving other related issues for potential remand.

Summary authored by Armon B. Shahdadi, Esq.