Tradtional Rules of Claim Construction Trim Plaintiff's Infringement Claim

Byrne v. The Black & Decker Corporation, [06-1523](May 21, 2007)[GAJARSA.Rader, O'Malley) NONPRECEDENTIAL The Federal Circuit affirmed summary judgment of non-infringement of U.S. Patent No. RE 34,815 on a patent on a flexible flail trimmer
BRIEF: At issue was the term "generally planer surface" which giving the term its ordinary meaning, the trial court found was not met by Black & Decker's U-shaped loop. LOF: While claim construction is a question of law, infringement is a question of fact. The meaning of a claim is determined by using intrinsic evidence which includes the claims, the specification, and the prosecution history and by using extrinsic evidence which includes dictionaries. Extrinsic evidence may be less reliable: "extrinsic evidence may be useful to the court, but it is unlikely to result in a reliable interpretation of patent claim scope unless considered in context of intrinsic evidence. Heavy reliance on the dictionary divorced form the intrinsic evidence risks transforming the meaning of the claim term to the artisan into the meaning of the term in the abstract, out of its particular context, which is the specification. Byrne complained about the use of the accused device in the claim construction, but the Federal Circuit responded that "there is a distinction between performing claim construction and deciding what should be construed." A court may consider the accused device to determine what part of the claim must be construed.
The Federal Circuit held that the district court erred when it found that the accused Black & Decker device did not have a surface, but found that summary judgment was still appropriate because the accused device lacked a generally planar surface.