Claim construction is perhaps the single most crucial factor in most patent disputes, but it is also one of the most convoluted. Beyond all the other intricacies involved in claim construction, another wrinkle is that the U.S. has two claim construction standards: (1) the “broadest reasonable interpretation” (“BRI”) standard applied by the U.S. Patent and Trademark Office (PTO); and (2) the Phillips standard used in district court litigation.1 The PTO BRI standard, which has now been articulated in the PTO Rules implementing the AIA,2 means that patent claim scope is determined not only on the basis of claim language, but by “giving claims their broadest reasonable construction ‘in light of the specification as it would be interpreted by one of ordinary skill in the art.’”3 On the other hand, the Phillips standard used by district courts gives claim terms “the meaning that the term would have to a person of ordinary skill in the art in question at the time of the invention.”4 Importantly, the district court conducts its analysis on the entire record before the court, which may include both intrinsic evidence (the claims, specification, and prosecution history) as well as extrinsic evidence (dictionary definitions and expert testimony), whereas the Patent Trial and Appeal Board (PTAB) generally affords less weight to extrinsic evidence.5

In the instances where the same claim terms have been construed by both the PTO and the district court, the most practical effect has been the influence on the PTAB of the district court’s proceedings. Sometimes the PTAB has simply adopted a district court’s claim construction.6 In Google v. Simpleair for example, the PTAB looked at the district court’s construction of nine claim terms in the co-pending litigation and determined that each construction was “consistent with their broadest reasonable interpretation in light of the specification.”7 The PTAB thus adopted the district court’s constructions, but perhaps they were inclined to do so as both parties had requested this of the PTAB.8 Even if the PTAB does not adopt the district court’s claim construction, the patent owner’s arguments in the district court can be considered by the PTAB, as discussed more fully below, which in turn can make the PTAB a more favorable forum for the patent challenger.

Furthermore, the PTAB’s claim construction can provide guidance to the district courts, which some jurisdictions are more willing to consider than others. For those jurisdictions willing to consider the PTAB’s construction, this could at least provide early insights for both sides.9 Additionally, the Federal Circuit has noted that “[t]he broadest reasonable interpretation of a claim term may be the same as or broader than the construction of a term under the Phillips standard. But it cannot be narrower.”10 Therefore, a PTAB’s construction can be viewed as setting an outer bound.

Even when the PTAB and the district court take their different analytical pathways, the end result may still be the same. The Federal Circuit noted this would have been true in their first reversal of a PTAB IPR decision this past June.11 In Proxyconn, the Federal Circuit determined that the PTAB under the BRI standard erred as the unpatentability of eight of the claims was based on an “unreasonably broad construction” of certain terms.12

The BRI standard is more favorable to PTAB petitioners as more prior art may be used to invalidate the patent. Additionally, patent owners should proceed with caution in district court when advancing an infringement position that relies on a broad claim construction. Anyone may cite to the PTO “statements of the patent owner filed in a proceeding before a Federal court or the Office in which the patent owner took a position on the scope of any claim of a particular patent.”13 Thus, a patent owner may box themselves into a claim construction position that allows for more prior art in PTO proceedings assessing patentability.

Further variationsin the two standards and the practical implications will become clearer as the PTAB continues its unpatentability rulings. For now, it is vital for practitioners to evaluate planned constructions under each standard early on—especially in the context of parallel proceedings.

- Maureen Urbina