As dictated by 35 U.S.C. § 311, a petitioner can pursue inter partes review (“IPR”) before the Patent Trial and Appeal Board (“PTAB” or “Board”) based on certain grounds of anticipation or obviousness under 35 U.S.C. §§ 102 or 103, respectively. This prior-art based inquiry generally involves an evaluation of patents or printed publications that the petitioner relies on in an IPR petition. Other potential invalidity theories, such as indefiniteness under § 112, cannot form the basis for instituting an IPR. However, a recent decision from the PTAB illustrates a potential outcome in an IPR where the Board has nonetheless determined, on its own, that the challenged claims are indefinite.

Earlier this month, the PTAB terminated an IPR sua sponte, finding that the challenged claims were indefinite and, therefore, could not be construed – a step that is required before evaluating invalidity for obviousness. Blackberry Corp. v. MobileMedia Ideas, LLC, Case IPR2013-00036, Paper 65 (PTAB Mar. 7, 2014) (“Decision”). At issue in the IPR were claims directed towards a “mobile communication apparatus.” Each of the challenged claims recited a “processing means for encrypting the information signals prior to storage in said memory means.” The Board found that the recitation of this means-plus-function element invoked the requirements of § 112, ¶ 6, which states:

An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.

(emphasis added.)†

Regarding a “processing means for encryption,” the challenged patent’s specification described only a “microprocessor and the like.” The Board found that the disclosure of an apparent general purpose computer, without specifying the implemented algorithm, to be insufficient under § 112, ¶ 6. Decision, p. 13 (citing WMS Gaming, Inc. v. Int’l Game Tech., 184 F.3d 1339, 1349 (Fed. Cir. 1999) (“computer-implemented means-plus-function term is limited to the corresponding structure disclosed in the specification and equivalents thereof, and the corresponding structure is the algorithm.”).

Because the challenged claims were found to be indefinite, the Board determined that the proper scope of the claims could not be established without speculation. The Board, therefore, concluded that “we cannot conduct a necessary factual inquiry for determining obviousness—ascertaining differences between the claimed subject matter and the prior art” (Decision, p. 20), and, pursuant to 37 C.F.R. § 42.72, terminated the IPR without issuing a final written decision.

This decision is notable, because IPRs are recognized as being limited to addressing invalidity based on §§ 102 and 103. Petitioners and patent owners should, however, consider whether other issues, including § 112 indefiniteness, may prevent the Board from properly construing the patent’s claims. Where the Board perceives an inability to determine proper claim scope, the Board may terminate the proceeding without issuing a final decision, or may not institute the proceeding in the first place. It remains to be seen what impact a PTAB finding of indefiniteness could have in co-pending district court litigation, but a decision by the PTAB opining on the indefiniteness of a claim may have persuasive effect. In this case, however, the district court had previously declined to find the claims indefinite (although the court acknowledged the issue), but later granted summary judgment of non-infringement, and the case was dismissed prior to the Board’s decision.