Meaning of a Disputed Claim Term Cannot be Determined in a Vacuum

Realsource, Inc., v. Best Buy Co., Inc., [2007-1387, -1439] (June 23, 2008) [YOUNG, Michel, Gajarsa] NON-PRECEDENTIAL The Federal Circuit affirmed summary judgment of noninfringement of U.S. Patent No. 5,732,136 on a merchant specific debit card verification system.
BRIEF: The district court entered summary judgment after the patentee conceded that under the courts construction of two terms there was no infringement literally or under the doctrine of equivalents. The Federal Circuit said that the meaning of a disputed claim term cannot be determined in a vacuum, and that the claims must be read in the context of the written description and the prosecution history. The Federal Circuit found that these two sources, taken together, make clear that the patentee did not regard its invention as encompassing systems such as those used by the defendants, where the card contained no information other than the card number. The Federal Circuit rejected the patentees arguments for a broader definition in line with “information” as defined in the specification, noting that the claim referred to ID information, not merely information. Furthermore, the Federal Circuit rejected a claim differentiation argument first noting that claim differentiation is a guideline, not a rule, and further that claim differentiation may indicate that an independent claim is broader than a dependent claim, but it does not necessarily determine in what way it is broader.