Until recently, it was generally acknowledged that claims are interpreted more broadly during patent prosecution than in patent litigation.  The rationale was that a patent applicant can amend the claims but a patentee cannot.  But the law was not entirely clear on how much more broadly claims can be interpreted.  The US Court of Appeals for the Federal Circuit provided guidance yesterday holding that even in an inter partes review  (IPR), the USPTO cannot construe patent claims in a manner that ignores general claim construction principles. Microsoft Corp. v. Proxyconn Inc., No. 2014-1542 (Fed. Cir. June 16, 2015) (reversing the Patent Trial and Appeal Board’s (PTAB) decision to invalidate claims of a data access patent using an “unreasonably broad” claim construction).  Part of the problem is that while courts regard Phillips v. AWH, 415 F.3d 1303 (Fed. Cir. 2005)as the most seminal decision on claim construction, the USPTO never fully applied the shift in doctrine thatPhillips demanded.  Phillips instructs courts to use the intrinsic evidence (specification, claims, and prosecution history) as the principal source for claim interpretation and deemed extrinsic evidence (such as dictionaries) as less relevant and cautioned that it cannot be used to contradict the intrinsic evidence.

In contrast, the USPTO has continued to apply the “broadest reasonable interpretation in light of the specification” standard.  See, e.g., MPEP §2111.  The legal test is frequently cited, but its application tended to be incomplete and outdated.  MPEP §2111 reflects the USPTO’s guidance to Examiners for interpreting patent claims.  This section provides claim construction doctrine, but seven out of the nine cited cases were court decisions rendered before Phillips.  Moreover, the MPEP §2111 section heading reads “Claim Interpretation; Broadest Reasonable Interpretation.”  But even the heading omits the second half of the appropriate standard – “broadest reasonable interpretation in light of the specification.”  The remaining discussion focuses on a claim term’s “plain meaning” and cautions not to “import claim limitations from the specification,” but there is little guidance on how to interpret the claim in view of the specification.  

Proxyconn’s main argument on appeal was that the broadest reasonable interpretation standard of claim construction should not apply during IPRs because the patentee has limited ability to amend its claims in such proceedings.  The Federal Circuit disagreed, noting that it already settled this issue in In re Cuozzo Speed Techs., LLC, 778 F.3d 1271, 1282 (Fed. Cir. 2015). (The broadest reasonable interpretation standard in IPRs was “properly adopted by PTO regulation.”)  But the court cautioned the PTAB, saying, “That is not to say, however, that the Board may construe claims during IPR so broadly that its constructions are unreasonable under general claim construction principles.”  Proxyconn Slip Op. at 6.  The Federal Circuit held that the “protocol of giving claims their broadest reasonable interpretation” does “not include giving claims a legally incorrect interpretation.”  Slip Op. at 6. 

What exactly does this mean for the USPTO (in IPR proceedings or otherwise)?  The Federal Circuit set forth three key guidelines, citing to three post-Phillips cases:

  1. The “claims should always be read in light of the specification and teachings in the underlying patent.” Slip Op. at 7 (citing In re Suitco Surface, Inc., 603 F.3d1255, 1260 (Fed. Cir. 2010)).
  2. “The PTO should also consult the patent’s prosecution history in proceedings in which the patent has been brought back to the agency for a second review.”  Slip Op. at 7 (citing Tempo Lighting Inc. v. Tivoli LLC, 742 F.3d 973, 977 (Fed. Cir. 2014)).
  3. “Even under the broadest reasonable interpretation, the Board’s construction “cannot be divorced from the specification and the record evidence…” Slip. Op. at 7 (citing In re NTP, Inc., 654 F.3d 1279, 1288 (Fed. Cir. 2011)).

To dispel any ambiguity, the court held that a construction that is “unreasonably broad” and which does not “reasonably reflect the plain language and disclosure” will “not pass muster.” Slip. Op. at 7 (citing In re Suitco Surface, 603 F.3d at 1260.)  In sum, the general claim construction principles as settled by Phillips apply, even to the USPTO.  For patent practitioners, this guidance bolsters against a patentability challenge based on an unreasonably broad claim interpretation, particularly when noting that the Federal Circuit reversed the PTAB under an AIA review.