Defining Words Appearing In Construction Of A Claim Term, Not The Claim Term Itself, Also Requires Following The Intrinsic Evidence

This article previously appeared in Last Month at the Federal Circuit, May, 2012.

Judges: Lourie (author), Dyk (dissenting-in-part), Prost

[Appealed from N.D.N.Y., Senior Judge Kahn]

In Advanced Fiber Technologies (AFT) Trust v. J&L Fiber Services, Inc., No. 11-1243 (Fed. Cir. Apr. 3, 2012), the Federal Circuit revised the district court's construction of a term appearing only in the court's construction of a claim term, and therefore vacated SJ of noninfringement. The Court declined to address the district court's denial of SJ of no invalidity but affirmed SJ of no willful infringement.

The technology at issue relates to devices used to filter contaminants from paper pulp mixtures known as "stock" by passing the stock through screens with holes. The asserted U.S. Patent No. RE39,940 ("the '940 patent") resulted from a reissue of U.S. Patent No. 5,200,072 ("the '072 patent"). During prosecution of the reissue application, Advanced Fiber Technologies (AFT) Trust ("AFT") argued against a rejection in light of a prior art patent to Gillespie. Specifically, AFT argued that the '072 patent used terms of pulp treatment art and offered definitions from the Handbook of Pulp and Paper Terminology (the "Handbook"). According to the Handbook, "screen" and "screen plate" meant a perforated barrier. AFT further argued that Gillespie taught slots "over three times the size" compared with the size of the slots in the claimed invention. Slip op. at 7. In response, the PTO withdrew the rejection and reissued the patent as the '940 patent.

AFT sued J&L Fiber Services, Inc. ("J&L"), which asserted noninfringement and invalidity based on a number of prior art references. The district court construed "screening medium" and "screening plate" as "a perforated barrier through which stock is passed to remove oversized, troublesome, and unwanted particles from good fiber." Id. at 8 (quoting Advanced Fiber Techs. Tr. v. J&L Fiber Servs., Inc.,

751 F. Supp. 2d 348 361 (N.D.N.Y. 2010)). At AFT's request, the district court further construed "perforated," which appeared in the district court's construction but not the claims themselves. The district court looked to general and technical dictionary definitions to conclude that "perforated" means "pierced or punctured with holes." Id. (citation omitted). The district court observed that the patent specification contains a "one-sentence mention that 'a wedgewire screening plate may be used,'" but viewed the disclosure as...