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Interpretation of Means-Plus- Function Limitation Defeats Likelihood of Success on Infringement

January 18, 2001

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Last Month at the Federal Circuit - February 2001

Judges: Dyk (author), Bryson, and Plager

In Globetrotter Software, Inc. v. Elan Computer Group, Inc., No. 00-1110 (Fed. Cir. Jan. 18, 2001), the Federal Circuit affirmed a district court’s denial of the patent holder’s motion for preliminary injunction.

As owner of U.S. Patent No. 5,390,297 (“the ‘297 patent”) directed to a license management system, Globetrotter Software, Inc. (“Globetrotter”) sued Elan Computer Group, Inc. (“Elan”) for infringement of the ‘297 patent and filed a motion for preliminary injunction and partial SJ of infringement of claim 55. Elan filed a cross-motion for partial SJ of noninfringement of claim 55. The license management system claimed in the ‘297 patent controls the number of program copies in use on a computer network based on the number of licenses purchased by a licensee. In one embodiment, each license is stored in a separate license file. When a computer user requests to use a program, the license management system determines whether the corresponding license files contain a license. If the license files do not contain a license, the license management system searches for an available license and transfers the license to the license file and grants the request. In the second embodiment, several licenses are stored in a single license file. When a computer user requests to use a program, the license management system grants the request if the license file contains a license. Each time a request is granted, the license management system decrements by one a counter indicating the number of remaining licenses.

Claim 55 generally recites a “license file means” for storing licenses. After conducting a Markman hearing, the district court had ruled that a “license file means for storing” is defined as an area of memory capable of storing at least one license and containing at least a unique identification (“UID”) assigned to the license file. The district court had further ruled that the UID is a necessary structure to perform the function of storing licenses. Finding that Globetrotter had failed to show that Elan’s license management system included a UID, the district court denied Globetrotter’s motion for preliminary injunction and partial SJ and granted Elan’s motion for partial SJ of noninfringement of claim 55.

On appeal, asserting that a UID is not necessary to perform the function of storing a license, Globetrotter argued that the district court improperly interpreted the “license file means” to include a UID. Globetrotter, relying on the doctrine of claim differentiation, also argued that claim 58, a dependent claim of claim 55, recites “means for assigning a UID” and therefore, claim 55 should not be interpreted to include the UID. The Federal Circuit rejected Globetrotter’s arguments and affirmed the district court’s conclusion that the corresponding structure of the “license file means” is a license file that includes a stored UID. The Federal Circuit also concluded that the holding that the “license file means” includes a UID does not import into claim 55 the “means for assigning a UID” limitation of claim 58.