Considering the issue of prosecution disclaimer, the U.S. Court of Appeals for the Federal Circuit found that a patentee’s statements during reexamination did not unambiguously disavow or clearly describe the structure of a claim term in dispute, and thus did not limit the scope of the claim term. Grober et al. v. Mako Products, Inc. et al., Case Nos. 10-1519; -1527 (Fed. Cir. July 30, 2012) (Rader, C. J.).

David Grober won an Academy Award in technical achievements for his platform that stabilizes a camera for filming motion pictures, known in the industry as Perfect Horizon. Grober received a patent that covers his camera stabilizing platform. After Grober filed suit alleging that Mako’s MakoHead product infringed the patent, Mako commenced an inter partes reexamination of the patent at the U.S. Patent and Trademark Office (PTO) and the district court case was stayed. After the reexamination concluded, the district court stay was lifted and claim construction commenced.

The claim term in dispute was “payload platform.” During the reexamination Grober distinguished his invention from the prior art by explaining that the prior art does not teach fixing or mounting sensors to a prior art element that the examiner associated with the claim term “payload platform.” Relying heavily on the reexamination proceedings, the district court construed the term to mean “the horizontal plate, piece of surface upon which the device (e.g., a camera) is direct mounted upon or affixed to.” Based on its claim construction, the district court found that MakoHead did not infringe. Grober appealed.

In reviewing the claim construction de novo, the Federal Circuit vacated the district court’s construction and remanded the case for further proceedings. The Court held that “[w]hen a patentee makes a clear and unmistakable disavowal of scope during prosecution, a claim’s scope may be narrowed under the doctrine of prosecution disclaimer.” However, while the Court acknowledged that this doctrine also applies to statements made during reexamination proceedings, the Court emphasized that the doctrine “only applies to unambiguous disavowals.”

With reference Grober’s statements to the PTO, the Court found that “[t]hese statements do not address the characteristics of the claimed payload platform limitation.” Rather, the Court explained that Grober’s statements referenced the prior art element in discussing the location of the sensors. The Court concluded that Grober’s statements which referenced the prior art are not an unambiguous disavowal that clearly and unmistakably disclaims claim scope or meaning, and thus the district court improperly limited the scope the disputed claim term.