Federal Circuit No 2012-1014

A divided en banc Federal Circuit upheld the rule that claim construction is a question of law which is reviewed de novo on appeal. As a result, the court reinstated the previous panel decision finding the asserted claims invalid for lacking sufficient corresponding structure for claimed means-plus-function elements under 35 U.S.C. § 112. 

In its panel decision, the Federal Circuit applied the Cybor standard of de novo review of claim construction on appeal. In granting Lighting Ballast's petition for rehearing en banc, the Federal Circuit invited supplemental and amicus briefing regarding whether (1) the court should overrule Cybor, (2) whether deference should be afforded to any aspect of a district court's claim constructions, and (3) if so, which aspects should be afforded deference. After reviewing the supplemental briefing and 21 amicus briefs, the court identified three distinct positions. 

The first position identified by the court is that Cybor should be overruled. This position is grounded in the belief that Cybor'sreliance on Markman v. Westview Instruments, Inc., 517 U.S. 370 (1996) is misplaced, as the Court in Markman focused merely on whether questions of claim construction should be subject to jury trial or decided by a judge. Furthermore, it is argued that Cyborcontradicts Federal Rule of Civil Procedure 52(a)(6), which provides that findings of fact must not be set aside unless clearly erroneous. 

The second identified position proposed a mixed or hybrid review of claim construction on appeal. Under this approach, factual aspects of claim construction would be reviewed under the clear error standard while district court claim construction determinations would be reviewed de novo as a matter of law. Included in this position was a proposal that the review standard should be based on whether the district court based its interpretation on intrinsic or extrinsic evidence. For intrinsic evidence, de novo review would apply, whereas clear error would be the standard of review for extrinsic evidence. 

The third position identified by the court is that the existing plenary review standard is correct. The third position believes that Cyborwas correctly decided and that claim construction is a purely legal matter which should receive de novo review. Additionally, this position believes that a changed standard may result in differing district court constructions of the same patent which would then be required to receive deference on appeal, and would raise forum shopping concerns. 

Ultimately, the en banc court affirmed the previous panel decision in a 6-4 split, taking the third position that claim construction is a matter of law subject to de novo review. The majority relied heavily upon the doctrine of stare decisis and fifteen years of decisions applying Cybor. The majority believed that a better alternative to Cybor has not been proposed, and that although controversy exists surrounding Cybor, that "there must be more than controversy [to overturn an en banc ruling that has had long and wide application]." Rather, the majority noted that there must be a compelling justification to overturn Cybor's precedent. 

Judge O'Malley's dissenting opinion in Lighting Ballast (joined by Chief Judge Rader and Judges Reyna and Wallach) advocates for mixed or hybrid review of claim construction on appeal, reviewing district court claim construction de novo while reviewing underlying factual determinations for clear error. 

As a result of Lighting Ballast, Cybor was upheld and claim construction remains a matter of law which is reviewed de novo on appeal. However, there is significant opposition to Cybor amongst the judges at the Federal Circuit. It appears that the majority's reliance on stare decisis was more of a statement of not currently recognizing a more workable alternative than an outright affirmation of Cybor. It is unclear whether the Supreme Court would grant certiorari if Lighting Ballast appeals the en banc Federal Circuit decision, but if granted, Supreme Court guidance regarding the scope of its previous Markman decision and the proper standard of review for claim construction could have major impacts on patent litigation moving forward.