District Court Tried Too Hard to Resist Importing Limitations from the Specification

The Chamberlain Group, Inc. v. Johnson Controls Interiors LLC, [2007-1314, 1467](February 19, 2008)[RADER, Clevenger, and DYK] The Federal Circuit reversed the the district court’s claim construction, vacated the preliminary injunction, and remanded the case.
BRIEF: Chamberlain’s exclusive licensee with respect to development of radio frequency transmitters for sale to automotive original equipment manufacturers, sued Lear Corp. charging Lear’s Car2U transmitter with infringement of claim 4 of the ’544 patent. Johnson Controls appealed. Although it is unacceptable to import limitations into a claim from the written description, the specification is always highly relevant to the claim construction analysis. Usually, it is dispositive; it is the single best guide to the meaning of a disputed term. At issue was the term "binary coded trinary number". The Federal Circuit explained the district court's interpretation, and then said: "The district court commendably strove to follow this court’s rules for claim construction. . . . In this regard, the trial court weighed the intrinsic evidence along with the extrinsic evidence and properly sought to avoid importing a limitation from the specification into the claims . . .. Nonetheless, this court discerns that the ’544 patent specification gives particular limiting meanings to the language in the claims. Specifically, the ’544 patent used "binary code" to mean "binary number." While the district court’s construction may represent an ordinary or customary reading of "binary code," the ’544 patent restricts "binary code" to a narrower meaning." The Federal Circuit determined that the errors in claim construction will fundamentally influence the likelihood of success in proving infringement. Thus, Federal Circuit vacated the preliminary injunction and remanded.