Disclosed Embodiment Does Not Necessarily Limit Scope of Means-Plus-Function Limitation

The U.S. Court of Appeals for the Federal Circuit has held that a means-plus-function claim limitation need not necessarily be construed to include all the attributes of the corresponding structure recited in the specification. Instead, a court should look to only so much of the structure as is needed to perform the claimed function. Golight, Inc. v. Wal-Mart Stores, Inc., Case No. 02-1608 (Fed. Cir. Jan. 20, 2004).

Golight sued Wal-Mart for infringing its patent on a wireless, remote-controlled, portable search light. One limitation of the claim at issue required a "horizontal drive means for rotating said lamp unit in a horizontal direction." The only structure in the specification corresponding to a "horizontal drive means" was in the description of the preferred embodiment, which the specification explicitly stated must be capable of rotating through 360°. At trial, Wal-Mart argued its product did not infringe because it was incapable of moving through a full 360°. The trial