DCT

1:19-cv-02421

ClearOne Inc v. Shure Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:19-cv-02421, N.D. Ill., 12/16/2019
  • Venue Allegations: Venue is alleged to be proper in the Northern District of Illinois because Defendant Shure is headquartered and regularly transacts business in the district.
  • Core Dispute: Plaintiff alleges that Defendant’s professional microphone arrays, when combined with digital signal processors that perform acoustic echo cancellation, infringe a patent on a computationally efficient method for processing audio in conferencing systems.
  • Technical Context: The technology at issue involves digital signal processing in beamforming microphone arrays, a category of high-performance audio equipment used in professional conferencing environments to isolate a speaker's voice and eliminate echo.
  • Key Procedural History: The complaint notes that Defendant previously challenged the patent-in-suit, U.S. Patent No. 9,264,553, in an Inter Partes Review (IPR) proceeding before the Patent Trial and Appeal Board (PTAB). In that proceeding, the PTAB issued a Final Written Decision concluding that Defendant had not demonstrated that the challenged claims were unpatentable, and subsequently denied Defendant's request for rehearing.

Case Timeline

Date Event
2011-06-11 U.S. Patent No. 9,264,553 Priority Date
2016-01-01 Shure announces release of MXA910/MXA310 microphones (approx.)
2016-02-16 U.S. Patent No. 9,264,553 Issues
2016-08-01 Shure begins shipping MXA910/MXA310 microphones (approx.)
2017-04-24 Shure files declaratory judgment action regarding the ’553 Patent
2017-07-14 Shure files petition for Inter Partes Review of the ’553 Patent
2019-01-24 PTAB issues Final Written Decision in IPR, finding claims not unpatentable
2019-03-25 PTAB denies Shure's Request for Rehearing
2019-12-16 Complaint Filed

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 9,264,553 - “Methods and Apparatuses for Echo Cancelation with Beamforming Microphone Arrays”

  • Patent Identification: U.S. Patent No. 9,264,553, “Methods and Apparatuses for Echo Cancelation with Beamforming Microphone Arrays,” issued February 16, 2016.

The Invention Explained

  • Problem Addressed: In audio conferencing systems using microphone arrays, two critical processing steps are beamforming (focusing on a speaker) and acoustic echo cancellation (AEC) (removing sound from the far-end speaker). Performing AEC on every individual microphone signal before beamforming ("AEC first") is computationally expensive and limits the number of microphones that can be used, while performing beamforming first and then AEC on the single resulting audio stream ("beamformer first") can degrade performance, especially when the active speaker changes ('553 Patent, col. 8:14-30; Compl. ¶41-42).
  • The Patented Solution: The patent discloses a "hybrid" method that balances computational load and audio quality. The system first performs beamforming on the signals from "N" microphones to create a smaller number, "M," of combined signals corresponding to different "fixed beams." It then performs AEC on this smaller set of "M" signals before selecting the final audio stream for transmission ('553 Patent, Abstract; Fig. 9). This approach minimizes processing effort by not applying AEC to every raw microphone channel, while maintaining high-quality echo cancellation on pre-formed audio beams (Compl. ¶41, 43).
  • Technical Importance: This hybrid architecture enabled the use of a larger number of microphones for superior audio capture without the prohibitive processing costs associated with the "AEC first" approach (Compl. ¶43).

Key Claims at a Glance

  • The complaint asserts independent claims 1, 8, and 15 (Compl. ¶76).
  • The essential elements of independent method Claim 1 include:
    • sensing acoustic waves with a plurality of microphones;
    • performing a beamforming operation to combine the microphone signals into a smaller plurality of combined signals corresponding to different fixed beams;
    • performing an acoustic echo cancelation operation on the plurality of combined signals; and
    • selecting one or more of the resulting echo-canceled signals for transmission.
  • The complaint reserves the right to assert additional claims ('553 Patent, Claim 1; Compl. ¶76).

III. The Accused Instrumentality

Product Identification

  • The accused instrumentalities are integrated systems comprising Shure’s MXA910 Ceiling Array and MXA310 Table Array microphones used in combination with a digital signal processor (DSP) that provides acoustic echo cancellation (AEC) (Compl. ¶9, 46-47, 73).

Functionality and Market Context

  • The Shure MXA910 and MXA310 are beamforming microphone arrays designed for professional AV conferencing environments (Compl. ¶74). The complaint alleges they perform a beamforming operation by combining signals from multiple microphone elements to produce multiple "highly-directional pickup lobes" (Compl. ¶46).
  • These microphone arrays require, but do not contain, AEC functionality. The complaint alleges that Shure instructs and encourages end users to provide this functionality by connecting the microphones to external DSPs, such as Shure’s own IntelliMix P300 or third-party processors from companies like QSC and Biamp (Compl. ¶47, 73). The complaint alleges that the combination of the Shure microphone and the external DSP creates an infringing system that performs beamforming first, followed by AEC on the resulting combined signals (Compl. ¶74).
  • A system overview diagram from an accused product's user guide illustrates the microphone (1) connected to a network where audio is processed and routed to far-end participants (Compl. Ex. H, p. 2). The complaint alleges that upon their release, Shure became the only U.S. company selling a beamforming microphone array substantially similar to Plaintiff's own BMA product (Compl. ¶48).

IV. Analysis of Infringement Allegations

’553 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
sensing acoustic waves with a plurality of microphones to develop a corresponding plurality of microphone signals; The accused Shure MXA910 and MXA310 are microphone arrays that contain multiple microphone elements to capture audio. ¶73 col. 10:52-54
performing a beamforming operation to combine the plurality of microphone signals to a plurality of combined signals...each...corresponding to a different fixed beam; The accused microphones allegedly "combine '[m]ultiple mic elements together to produce multiple, highly-directional pickup lobes'," which the complaint equates to the claimed "fixed beams." ¶46 col. 10:55-65
performing an acoustic echo cancelation operation on the plurality of combined signals to generate a plurality of combined echo-canceled signals; Shure's microphones are allegedly combined with external DSPs (e.g., Shure IntelliMix P300, QSC Q-SYS) that perform the required AEC on the combined signals received from the microphone array. ¶47, 74 col. 11:1-4
and selecting one or more of the plurality of combined echo-canceled signals for transmission. The integrated system allegedly selects the processed audio from the active beam(s) and transmits it for conferencing purposes. A user guide for the accused MXA910 illustrates the targeted capture of participant audio using up to eight independent lobes (Compl. Ex. I, p. 2). ¶73-74 col. 11:5-8

Identified Points of Contention:

  • Scope Questions: The complaint's theory appears to rely on a combination of products from different manufacturers (e.g., a Shure microphone and a Biamp DSP). This raises the question of liability for divided infringement: can the claim elements, performed by separate devices, be attributed to Shure for purposes of direct or indirect infringement? The complaint alleges Shure instructs customers to create these infringing systems, which may support its claims for indirect infringement (Compl. ¶73, 76).
  • Technical Questions: A potential point of dispute may be whether the accused products' "highly-directional pickup lobes," which product literature describes as "Steerable Coverage," constitute the "fixed beams" required by the claims (Compl. ¶46; Ex. I, p. 2). The analysis may turn on whether a beam that is electronically steerable or configurable prior to operation can be considered "fixed" during operation for the purpose of the claimed invention.

V. Key Claim Terms for Construction

  • The Term: "fixed beam"
  • Context and Importance: This term is central to the infringement analysis. The accused products are marketed as having "Steerable Coverage" with adjustable "lobes." The case may turn on whether these configurable lobes meet the "fixed beam" limitation. Practitioners may focus on this term because if "fixed" is construed to mean immutable or non-steerable, Defendant may argue its technology falls outside the claim scope.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The patent specification describes the "hybrid configuration" as generating "a number of fixed beams followed by echo cancelers for each fixed beam" ('553 Patent, col. 8:38-40). Plaintiff may argue that "fixed" refers to the state of the beams during processing (i.e., applying AEC to a stable set of M beams), not that the beams are incapable of being aimed or configured beforehand.
    • Evidence for a Narrower Interpretation: The patent contrasts its solution with prior art "beamformer first" methods that suffered performance issues due to "changing characteristics of the beamformer" ('553 Patent, col. 8:19-21). Defendant may argue that "fixed beam" was chosen to distinguish the invention from such systems with dynamically changing characteristics, implying a more static configuration.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges both induced and contributory infringement. It alleges inducement based on Shure's instructions, user guides, and marketing materials that allegedly encourage customers to combine the accused microphones with DSPs to perform the patented method (Compl. ¶73, 76). The complaint also cites press releases and articles about Shure's partnerships with DSP manufacturers Biamp and QSC as evidence of intent (Compl. ¶75, Ex. J-O). Contributory infringement is alleged on the basis that Shure's microphones are a material component of the invention, are not staple articles of commerce, and have no substantial non-infringing use without the AEC functionality provided by a DSP (Compl. ¶73, 76).
  • Willful Infringement: The complaint alleges that Shure had knowledge of the ’553 Patent no later than when it filed a declaratory judgment action against ClearOne in April 2017 (Compl. ¶50, 82). It further alleges that Shure's infringement continued even after the PTAB declined to invalidate the patent claims in an IPR that Shure initiated, which may be presented as evidence of objective recklessness (Compl. ¶49, 53, 83).

VII. Analyst’s Conclusion: Key Questions for the Case

  • A central legal issue will be one of divided infringement liability: given that the accused Shure microphones perform the claimed beamforming step while a separate DSP (often from a third party) performs the claimed echo cancellation step, can ClearOne establish that Shure is liable for either direct or indirect infringement of the asserted system and method claims?
  • A key claim construction question will be one of definitional scope: does the claim term "fixed beam," which is central to the patent's "hybrid" processing architecture, read on the electronically steerable and configurable "pickup lobes" of the accused Shure microphone arrays?
  • An underlying evidentiary question will be one of intent: what evidence exists to demonstrate that Shure specifically intended for its customers to combine its microphones with third-party DSPs in a manner that practices all steps of the patented method, particularly in light of the extensive history between the parties?