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Specification and Expert Testimony Supported Construction of “Mean Grain Diameter” to Require Calculation Based on Numbers of Particles, Not Volume

06-1282
October 31, 2007
Wang, Ningling

Decision icon Decision

Last Month at the Federal Circuit - November 2007

Judges: Newman (author), Rader, Dyk (dissenting)

[Appealed from: ITC]

In Osram GmbH v. International Trade Commission, No. 06-1282 (Fed. Cir. Oct. 31, 2007), the Federal Circuit reversed the ITC’s decision of noninfringement because of an incorrect claim construction, and remanded for further proceedings.

Osram GmbH and Osram Opto Semiconductors GmbH (collectively “OSRAM”) requested the ITC initiate an investigation, alleging that Dominant Semiconductors Sdn. Bhd. (“Dominant”) violated section 337 by importing and selling compositions that infringe at least one claim of OSRAM’s five U.S. patents (collectively “the Particle Size Patents”). The Particle Size Patents are directed to wavelength-converting compositions comprising luminous phosphor particles that convert the emitted light of light-emitting diodes (LEDs) to a different wavelength in order to produce the desired white light. The key issue on appeal turned on the construction of the claim limitation, “mean grain [i.e., particle] diameter d50 < 5 μm.”

The ITC deemed it unclear whether the claimed “mean grain diameter” should be measured as the average diameter based on the number of grains or the average diameter based on the volume of grains, because the patent specifications did not indicate how the mean grain diameter is determined. Nevertheless, the ITC selected the volume-based average based on two technical treatises and evidence that it is common for phosphor manufacturers to report phosphor size for sale to customers by volume. After remanding to the ALJ, the ALJ then found that Dominant’s “Fine Series LED” phosphors fell within the scope of the claims and infringed, whereas Dominant’s “Normal Series LED” phosphors did not. Further, the ALJ determined that OSRAM’s own products fell outside the claim limitation when measured by the volume-based method; therefore, OSRAM did not meet the “technical prong” of the domestic industry requirement under section 337. Accordingly, the ALJ held that the imported products did not violate section 337. The ITC affirmed and OSRAM appealed.

The Federal Circuit reversed, concluding that the ITC erred in construing “mean grain diameter” as the volumetric mean, rather than the number-based mean. The Court noted that “[t]he experts for both sides were in full and emphatic agreement that the ordinary meaning of the average diameter of these particles is the number-based average—until Dominant’s expert later changed his position” when it became apparent that this issue could determine liability. Slip op. at 7. The Court also found that the patent specifications were “in accordance with a number-based mean, for the invention stresses the homogeneity of size, not volume, of the phosphor particles.” Id. at 8. And the Court noted that it was not disputed that homogeneity of size is better reflected in a number-based average than a volume-based average.

The Court further reasoned that “[w]hen there is more than one method of measurement and the patent does not explicitly discuss the methods, persons experienced in the field are reasonably deemed to select the method that better measures the parameters relevant to the invention.” Id. at 9. Under this framework, the Court concluded that “[a]ll of the experts agreed that the volume-based measure [was] more sensitive to large particles, which do not function in the invention, and that the number-based measure was more sensitive to the size and distribution of the particles that perform the inventive function.” Id. at 9-10.

The Federal Circuit thus concluded that the ITC “erred in construing the claims as requiring the volume-based method, contrary to the ordinary meaning of the term as reflected in the specification and the testimony, and at odds with the purposes of the invention.” Id. at 10. The Court stated that its conclusion was reinforced by the undisputed fact that the volume-based measure would exclude the OSRAM products that the patents were designed to cover.

Judge Dyk dissented and explained that the number-based method and the volume-based method are used in the industry for different purposes: the number-based method is used for research and development purposes while the volume-based method is used commercially in the sale of phosphor powders. Judge Dyk agreed with the ITC’s claim construction that “mean grain diameter” was a volume-based average, because, in his view, the patent specifications “make it quite clear that a commercial invention is being described.” Dyk Dissent at 3.