Federal Circuit Summaries

Before Moore, Wallach, and Stoll. Appeal from the Patent Trial and Appeal Board.

Summary: The PTAB is entitled to weigh the credibility of expert witnesses, and attorney argument cannot be used as evidence to rebut actual admitted evidence.

Elbit sought inter partes review, challenging various claims of Thales’s patent as being obvious. In response, Thales argued that the limitation of calculating the “relative angular rate signal” was not explicitly disclosed in the prior art. Thales’s expert explained that this limitation is a two-step method and the prior art uses a three-step method. Elbit’s expert testified that two- and three-step methods are “mathematically equivalent” and have no practical difference. However, the PTAB found that Elbit’s expert testimony was unsupported and entitled to little weight because he did not address this limitation anywhere in his opinion. In contrast, the PTAB credited the testimony of Thales’s expert and concluded that Elbit had failed to meet its burden of proving the asserted claims were unpatentable.

The Federal Circuit affirmed, stating that Thales’s expert testimony constitutes substantial evidence that the prior art does not teach the “relative angular rate signal” limitation. The Federal Circuit explained that the PTAB is entitled to weigh the credibility of witnesses and declined to disturb those credibility determinations. Elbit also argued on appeal that the PTAB failed to credit the knowledge of a person of ordinary skill, but the Federal Circuit found that Elbit relied solely on attorney argument, which is not evidence and cannot rebut the admitted evidence.