Abstract

     In its recent decision in Honeywell Int’l, Inc. v. U.S. Int’l Trade Commission, the U.S. Court of Appeals for the Federal Circuit affirmed a final determination by the U.S. International Trade Commission (“ITC” or “Commission”) that the claims of Honeywell’s U.S. patent (“‘976 patent”) were invalid as indefinite under 35 U.S.C. § 112, second paragraph. Honeywell is unique in that the dispute was not so much over the meaning of the term at issue, “melting point elevation” (“MPE”), as it was over how to determine its value. Finding that where there were multiple methods known in the art for determining the melting point of polyethylene terephthalate (“PET”) yarn, and that different methods yielded significantly different results, the Federal Circuit concluded the claims were indefinite because they failed to reasonably apprise competitors whether their products were within the scope of the claims. This case should serve as a warning to patentees and practitioners to ensure that any quantitative parameters or formulae in their claims have single, well-understood meaning in the art or are clearly defined in the patent or prosecution history, particularly where the patentees have invented that parameter or formula for the purpose of drafting their claims.