On March 26, 2015, the Patent Trial and Appeal Board (PTAB) issued a decision denying Dell, Hewlett-Packard and NetApp’s (the “petitioner”) petition for inter partes review, finding that petitioner was estopped from requesting a subsequent proceeding. The PTAB has since designated this decision as representative of the application of the estoppel rule. 

Petitioner’s request for review asserts prior art that was asserted by petitioner against the same patent in an earlier request for inter partes review—the ’635 IPR. The same art was asserted in both petitions, but with different arguments—switching between obviousness and anticipation. In the ’635 IPR, the board instituted trial and entered a final written decision finding that the patent had not been shown to be unpatentable. 

In the instant case, the PTAB found that petitioner was estopped from requesting inter partes review under 35 U.S.C. §315(e)(1). The statute allows the board to deny review requests that contain prior art already presented in a proceeding that resulted in a final written decision. The instant request met all the requirements to deny institution under the estoppel statute: (1) the petitioner here and in the ’635 IPR is the same; (2) there was a final written decision in the ’635 IPR; and (3) the prior art petitioner asserts was presented in the initial petition. The board concluded that the differences in the way that the prior art is asserted did not weigh in the board’s determination. What mattered is that the grounds that petitioner raises in the instant petition could have been raised in the ’635 IPR. 

The PTAB also concluded that two claims asserted were not precluded by estoppel because they were not previously reviewed, but they were nonetheless time-barred by § 315(b).  

Dell Inc. v. Elecs. And Telcomms. Research Institute, IPR 2015-00549 (PTAB Mar. 26, 2015).