Description of "The Invention" Limits Claim Scope

Data Encryption Corporation v. Microsoft Corporation, [2006-1603] (September 6, 2007)[PROST, Rader, Bryson] NON-PRECEDENTIAL The Court of Appeals for the Federal Circuit affirmed summary judgment of non-infringement of U.S. Patent No. 5,584,023.
SIGNIFICANCE: The Federal Circuit agreed that there was an express disavowal of claim scope by a statement in the specification about "the invention".
BRIEF: Plaintiff argued that the District Court erred in narrowly construing the claims, but the Federal Circuit found that language in the specification that "All data subject to encryption by operation of the present invention is maintained in an encrypted state in the buffer pool." (emphasis added) was an intentional disclaimer of claim scope, noting that the language was unambiguous, and disavowed coverage of systems that maintain data subject to encryption in an unencrypted state in the kernel memory buffer pool.