Much discussion has followed the PTAB’s June 11, 2013 opinion in Idle Free Systems, Inc. v. Bergstrom, Inc., IPR2012-00027, Paper 26. The main controversy has been the language included in the opinion stating that in motions to amend, the burden is on the Patent Owner to show a “patentable distinction over the prior art of record and also prior art known to the patent owner” (emphasis added). In the flurry of discussion and debate that has followed, the focus has been on what prior art is “known to the patent owner.” How much prior art does that include? Was this a new duty to search for prior art? How much knowledge of prior art might be imputed to the Patent Owner?

For Petitioners and Patent Owners, the phrasing led to much consternation over a potential corresponding duty to search for and disclose prior art in motions to amend. Fortunately, on July 15, 2015, the Board clarified the Idle Free language in another case, MasterImage 3D, Inc., et al. v. RealD Inc., IPR2015-00040, Paper 42. In MasterImage, the Board said “prior art known to the patent owner” simply means “no more than the material prior art that the Patent Owner makes of record in the current proceeding pursuant to its duty of candor and good faith to the Office under 37 C.F.R. § 42.11, in light of a Motion to Amend,” which should be an already familiar standard. Thus, the Board clarified that the obligation on the Patent Owner is no more than what the duty of candor and good faith has always been, and the Idle Free language was not intended to create an additional affirmative duty for the Patent Owner.

Since the MasterImage decision, the Board has been vocal about the importance of this clarification. On August 20, 2015, the acting chief judge of the PTAB, Nathan Kelley, said he hopes the MasterImage decision “gives people a little bit more of a sense of comfort when they make such a motion.” See R. Davis, Don’t Be Shy In Seeking AIA Amendments, PTAB Chief Says, Law360, available at Judge Kelley clarified that there is no “affirmative duty to search the prior art and go find for us something that you’re not aware of.”

While Judge Kelley’s remarks are not official decisions of the PTAB, they do shed light on the Board’s position in MasterImage and Idle Free. The Board seems to be encouraging motions to amend when supported with the appropriate prior art disclosures. So far, the Board “ha[sn’t] seen a huge number of them,” according to Judge Kelley, but perhaps the new MasterImage decision will change that.

For more information on motions to amend and new developments, join us for a Norton Rose Fulbright webinar focused on motions to amend on October 8, 2015. To request an invitation, please contact Stacey Hall at