A Patentee's Definition of a Claim Term Governs, Even if it is Contrary to the Ordinary Meaning

Honeywell International, Inc. v. Universal Avionics Systems Corp., [2006-1406, 1435] (July 3, 2007) [BRYSON, Plager, Gajarsa] The Federal Circuit affirmed the district courts interpretation of the U.S Patent No. 4,914,436 and affirmed the finding of infringement.
SIGNIFICANCE: A patentee's redefinition of a claim term need not be explicit, and it controls even if it is contrary to the ordinary meaning. It takes an unambiguous statement in the prosecution history to disclaim claim scope.
BRIEF: At issue was the use of the term "heading of the aircraft". The Federal Circuit found that the specification and prosecution history make clear, that the patentees used the term in a manner different from its ordinary meaning, and that "When a patentee defines a claim term, the patentee's definition governs, even if it is contrary to the conventional meaning of the term." The Federal Circuit further observed that "[a] claim term may be defined in a particular manner for purposes of the patent even 'without an explicit statement of redefinition.'" The Federal Circuit thus concluded that heading, as used in the patent, meant bearing, stating "to hold otherwise would not include within the scope of the claim a preferred embodiment that the patentees labeled an 'important feature of the present invention' and would ignore the patentees' definition of the term "heading" and their consistent use of that term throughout the prosecution history." With respect to another disputed claim term, the Universal argued that term had been defined in the prosecution history. However the Federal Circuit concluded that "[b]ecause the passage is ambiguous, we conclude that it does not constitute a sufficiently clear and deliberate statement to meet the high standard for finding a disclaimer of claim scope. Because the only challenge to the infringement determination relate to claim scope, the Federal Circuit affirmed the finding of infringement as well.