The U.S. Court of Appeals for the Federal Circuit reversed the claim construction ruling of the International Trade Commission (ITC), concluding that in light of the correct construction, the ITC’s determination of non-infringement and lack of domestic industry was in error. OSRAM GmbH v. International Trade Commission, Case No. 06-1282 (Fed. Cir., Oct. 31, 2007) (Newman, J.).
OSRAM’s patents are directed to compositions, methods and uses wherein luminous pigment powders contain phosphors that produce a spectral shift in the light emitted by electroluminescent components such as LEDs. The administrative law judge in the case determined that the claim limitation "mean grain diameter d50 < 5 um" was invalid for indefiniteness since the symbol "d" is commonly defined as "median," while the claim uses the term "mean." The ITC disagreed, finding that the claim limitation meant "mean" or "mathematical average," citing the general rule that words prevail over symbols. The ITC further held that the "mean" should be calculated based on the volume of grains rather than the number of grains. Based on this construction, the ITC held that the respondent’s products did not infringe and that OSRAM did not satisfy the domestic industry requirement of § 337. OSRAM appealed
The Federal Circuit reversed, ruling that the claim term "mean" should be calculated based on the number of grains, not the volume. The Court primarily relied on the testimony of the parties’ experts, who initially agreed that the number-based average was appropriate. Given that the specification did not provide any guidance on the method of measurement, the Court found it appropriate to rely on the testimony of those experienced in the field. The Court also noted that the number-based method was a more accurate method of measuring the existence of small particles that are beneficial to performance, while the volume-based method was a more accurate way of measuring the existence of large particles that are detrimental to performance. Thus, according to the Court, the number-based method was the correct choice, since the purpose of the claim limitation was to state the parameters of the products that work in the desired way, not those that may not. Using the number-based method of measuring, the Court found the claims were infringed and that OSRAM did meet the domestic industry requirement.
Practice Note
: Where a patent specification is unclear as to the method of calculating a measurement required by a claim limitation, so long as the claim is not "insoluably ambiguous," extrinsic evidence, such as expert testimony, will often determine the method that should be used.The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.