CAFC Clarifies Analysis of Intrinsic Evidence on Indefiniteness, Affirms PTAB’s Denial of Sanctions

“The Federal Circuit reiterated that a claim term’s mere susceptibility to multiple meanings doesn’t render it indefinite as ‘[s]uch a test would render nearly every claim term indefinite so long as a party could manufacture a plausible construction.’”

indefinite - June 1, the U.S. Court of Appeals for the Federal Circuit issued a precedential decision in ClearOne, Inc. v. Shure Acquisition Holdings, Inc. affirming a final written decision by the Patent Trial and Appeal Board (PTAB), which found that a substituted claim  offered by the patent owner, Shure, was not invalid due to an indefinite claim term. The Federal Circuit also affirmed the PTAB’s decision denying ClearOne’s request to file a motion for sanctions against Shure for the patent owner’s alleged violation of the duty to disclose material prior art.

PTAB Accepts Substituted Claim 57 Having “Self-Similar Configuration” Limitation

The patent-at-issue in ClearOne’s appeal from inter partes review (IPR) proceedings at the PTAB is U.S. Patent No. 9565493, Array Microphone System and Method of Assembling the Same. The ‘493 patent claims an array microphone system comprising a substrate upon which a plurality of microphones is arranged in a number of concentric, nested rings of various sizes, each ring having multiple microphones positioned at predetermined intervals along the ring’s circumference. In July 2019, Shure filed a lawsuit in the District of Delaware asserting the ‘493 patent against ClearOne for marketing an allegedly infringing ceiling tile beamforming microphone array.

In February 2019, about five months prior to Shure’s lawsuit in Delaware, ClearOne filed a petition for IPR proceedings at the PTAB to challenge the validity of the ‘493 patent. In August 2020, the PTAB entered a final written decision that invalidated more than 30 claims of the ‘493 patent, but also accepted 11 substitute claims offered by Shure containing limitations involving a sound-permeable screen covering the microphones and side rails securing two faces of the housing. Then in November 2020, the PTAB denied ClearOne’s request for rehearing of the final written decision, an order which also denied ClearOne’s request to file a motion for sanctions against Shure.

In substituted claim 57 of the ‘493 patent, the claimed microphone array is described as being “arranged in a self-similar configuration.” The PTAB accepted this substituted claim over ClearOne’s arguments that “self-similar” was not a specific term of art from acoustics or microphone design, and that its meaning within the ‘493 patent’s specification was ambiguous. The ‘493 patent’s specification discloses “a plurality of microphone transducers selectively positioned in a self-similar or fractal-like configuration, or constellation.” While ClearOne’s expert testified that the specification equated “self-similar” with “fractal-like” without any explanation of how close “fractal-like” is to an actual fractal, the PTAB found that “self-similar” had a well-known meaning from multiple dictionary sources and that the specification did not create a special meaning for that claim term.

CAFC: Intrinsic Evidence Alone Supports the PTAB’s Ruling of Not Indefinite

On appeal, the Federal Circuit found that the intrinsic evidence of the ‘493 patent’s specification alone provided the scope of the term “self-similar” with reasonable certainty. Disclosures in both the written description and patent drawings showed that the “self-similar” configuration referred to repeating or fractal-like configurations that can be arranged in repeating shapes such as ovals, squares, triangles or other polygons. While ClearOne argued that the ‘493 patent’s disclosures of “fractals” and “concentric circles” should be understood as distinct from “self-similar” configurations, the Federal Circuit ruled that those terms were examples of self-similar configurations and not distinct embodiments.

While the intrinsic evidence alone supported the PTAB’s indefiniteness finding, the Federal Circuit also took the extrinsic evidence of dictionary definitions and expert testimony into account in finding that the PTAB’s ruling was supported by substantial evidence.

“Dr. Begault, ClearOne’s own expert, testified that the term ‘refers to an object that is exactly or approximately similar to a part of itself (i.e., the whole has the same shape as one or more of the parts, which is also a characteristic of a fractal).’ Further, his ability to determine that prior art disclosed a self-similar microphone configuration ‘further supports the conclusion that a skilled artisan did understand the term with reasonable certainty’ (citing to Sonix Technology Co., Ltd. v. Publications International, Ltd., 2017).”

“ClearOne’s arguments for indefiniteness merely identify different ways one could interpret self-similar,” the Federal Circuit opinion authored by Chief Judge Kimberly Moore concluded. Citing to Nevro Corp. v. Boston Scientific Corp. (2020), the Federal Circuit reiterated that a claim term’s mere susceptibility to multiple meanings doesn’t render it indefinite as “[s]uch a test would render nearly every claim term indefinite so long as a party could manufacture a plausible construction.”

No Abuse of Discretion in Denying ClearOne’s Request for Sanctions at the PTAB

Having affirmed the PTAB’s ruling that substituted claim 57 of the ‘493 patent was not indefinite, the Federal Circuit addressed ClearOne’s appeal from the PTAB’s denial of the petitioner’s request to file a motion for sanctions against Shure. In its request to file for sanctions at the PTAB, ClearOne argued that Shure disclosed a pair of prior art references when it petitioned for post-grant review (PGR) of a ClearOne patent that Shure should have disclosed at the motion to amend stage of the IPR challenging the validity of the ‘493 patent. However, the PTAB found no violation of Shure’s duty to disclose material prior art as those references were cumulative of prior art references asserted in ClearOne’s IPR petition.

“The Board reasoned that allowing ClearOne to file its sanctions motion would be little more than a second opportunity at its IPR with the hindsight benefit of knowing the Board’s views of the deficiencies in its invalidity contentions.”

On appeal, the Federal Circuit found no abuse of the PTAB’s discretion in denying ClearOne’s request for sanctions. The PTAB held a hearing on the merits of ClearOne’s sanctions motion and issued an order explaining considerations weighing against ClearOne’s request. During oral arguments at the Federal Circuit, counsel for ClearOne conceded that the arguments in its sanctions motion were identical to arguments raised in ClearOne’s request for rehearing of the PTAB’s final written decision. The Federal Circuit affirmed the PTAB’s denial of ClearOne’s request for sanctions on this ground and did not analyze whether the prior art references raised in Shure’s PGR were cumulative of the prior art references in ClearOne’s IPR petition. The Federal Circuit also briefly addressed a due process argument raised by ClearOne, ruling that the PTAB’s procedures regarding the sanctions denial afforded ClearOne with notice and an opportunity to be heard by a disinterested decision maker.

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  • [Avatar for Peter Kramer]
    Peter Kramer
    June 6, 2022 10:05 pm

    Great article, Steve!