Specification’s Narrow Description of the Invention Results in Disavowal of Claim Scope

| Karen Cassidy Selvaggio


Before Lourie, Dyk, and Wallach. Appeal from the U.S. International Trade Commission.

Summary: Consistent description in the specification of a particular embodiment as the inventive aspect solving a problem in the prior art may amount to disavowal of claim scope, even in the absence of an express concession excluding alternative embodiments.

The Chamberlain Group filed a complaint at the U.S. International Trade Commission (“Commission”) alleging several companies, including Techtronic Industries, imported products that infringed its patent directed to a garage door opener. Although the Administrative Law Judge (“ALJ”) granted a summary determination of non-infringement, the Commission reversed the ALJ’s claim construction of the claim term “wall console” and vacated the initial determination of non-infringement. The ALJ then found the accused products infringed the patent and the Commission adopted the determination.

At issue before the Federal Circuit was whether the claim term “wall console” included wall-mounted garage door control units without passive infrared detectors. The court found it did not because the patent specification disclosed the invention as an improvement achieved by moving the passive infrared detector from the head unit to the wall console. The court noted the specification’s background section described the problems with the prior art garage door openers having the passive infrared detector in the head unit. The court then found the rest of the specification presented moving the detector to the wall console as the solution to the problem, and that the “entire specification focuses on enabling placement of the passive infrared detector in the wall console.”

The Federal Circuit rejected arguments that the disclosure did not amount to a disavowal when the specification did not state that it was “impossible” or “infeasible” to place the detector elsewhere. The Federal Circuit explained that because the specification “plainly represents the scope of the invention to the exclusion of some embodiments,” such explicit statements were unnecessary to find disavowal. The Federal Circuit then reversed the Commission’s construction of “wall console” and final determination of infringement.

Editor: Paul Stewart