DCT

1:19-cv-02421

ClearOne Inc v. Shure Inc

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Key Events
Amended Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:19-cv-02421, N.D. Ill., 07/30/2020
  • Venue Allegations: Venue is based on Defendant Shure having its corporate headquarters and regularly transacting business in the Northern District of Illinois.
  • Core Dispute: Plaintiff alleges that Defendant’s ceiling and table array microphones, when combined with digital signal processors for acoustic echo cancellation, infringe a patent related to audio conferencing technology.
  • Technical Context: The dispute involves digital signal processing techniques used in high-end audio-visual conferencing systems to improve audio clarity by forming directional microphone beams and eliminating echo.
  • Key Procedural History: The complaint alleges a significant history between the parties regarding the patent-in-suit. Defendant Shure previously filed a declaratory judgment action seeking to invalidate the patent and declare non-infringement. Shure also initiated an Inter Partes Review (IPR) proceeding before the Patent Trial and Appeal Board (PTAB). The complaint states the PTAB issued a Final Written Decision finding that Shure had not demonstrated the challenged claims were unpatentable, and subsequently denied Shure's request for rehearing. Plaintiff asserts that this history establishes Defendant's knowledge of the patent and may create an estoppel preventing Defendant from re-litigating certain invalidity arguments.

Case Timeline

Date Event
2011-06-11 ’553 Patent Priority Date
2012-01-01 Plaintiff ClearOne first markets its BMA product (approximate date)
2016-01-01 Defendant Shure announces release of accused MXA910/MXA310 products (approximate date)
2016-02-16 ’553 Patent Issued
2016-08-01 Defendant Shure begins shipping accused products (approximate date)
2017-04-16 Plaintiff files for reissue of the ’553 Patent
2017-04-24 Defendant files declaratory judgment action regarding the ’553 Patent
2017-07-14 Defendant files Inter Partes Review (IPR) petition against the ’553 Patent
2018-01-29 PTAB institutes IPR proceedings for the ’553 Patent
2018-03-16 Court declines jurisdiction over Defendant's declaratory judgment claim
2019-01-24 PTAB issues Final Written Decision in IPR, finding claims not unpatentable
2019-02-22 Defendant files Request for Rehearing of PTAB decision
2019-03-25 PTAB denies Defendant's Request for Rehearing
2020-07-30 Plaintiff files Second Amended Complaint

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 "’553 Patent") (Compl. ¶4; Ex. A).

The Invention Explained

  • Problem Addressed: In audio conferencing, sound from a far-end participant is played through local loudspeakers. Local microphones can pick up this sound and transmit it back, creating an undesirable echo for the far-end participant (Compl. ¶37). With advanced microphone arrays, two primary methods for solving this existed, each with significant drawbacks. The "AEC first" approach (performing Acoustic Echo Cancellation on every individual microphone signal before combining them) was computationally expensive and complex. The "beamformer first" approach (combining microphone signals into a single beam and then performing AEC) suffered from poor performance, as the echo canceller had to constantly re-adapt whenever the active speaker, and thus the beam's direction, changed (’553 Patent, col. 8:10-34; Compl. ¶¶39-40).
  • The Patented Solution: The ’553 Patent discloses a "hybrid" method that seeks to balance performance and computational efficiency. The system first performs a beamforming operation, combining signals from a large number ('N') of microphone elements into a smaller, intermediate number ('M') of distinct, fixed beams (’553 Patent, Fig. 9). Then, it performs acoustic echo cancellation separately on each of these 'M' fixed beams. Because the beams are fixed, the echo cancellers do not need to constantly re-adapt, and because 'M' is much smaller than 'N', the computational load is significantly reduced compared to the "AEC first" method (Compl. ¶¶39, 41; ’553 Patent, col. 9:50-col. 10:11).
  • Technical Importance: This approach enabled the use of sophisticated multi-microphone arrays to achieve superior audio quality without the prohibitive processing costs or performance flaws of prior art methods (Compl. ¶41).

Key Claims at a Glance

The complaint asserts independent claims 1, 8, and 15 (Compl. ¶¶75, 76).

  • Independent Claim 1 (Method):
    • Sensing acoustic waves with a plurality of microphones.
    • Performing a beamforming operation to combine the microphone signals into a plurality of combined signals, where the number of combined signals is between one and the number of microphone signals, and each combined signal corresponds to a different fixed beam.
    • Performing an acoustic echo cancellation operation on the plurality of combined signals.
    • Selecting one or more of the resulting echo-canceled signals for transmission.
  • Independent Claim 8 (Apparatus):
    • A plurality of microphones.
    • A processor configured to perform the beamforming, acoustic echo cancellation, and selection steps as recited in method claim 1.

The complaint reserves the right to assert additional claims (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 separate digital signal processors (DSPs) that provide Acoustic Echo Cancellation (AEC) (Compl. ¶¶21, 46, 73). Alleged DSPs include Shure's IntelliMix P300, QSC’s Q-SYS platform, and Biamp’s Tesira/TesiraFORTE audio processors (Compl. ¶¶45, 73). The complaint includes an image of Plaintiff's own Beamforming Microphone Array product for market context (Compl. p. 3).

Functionality and Market Context

  • The Shure MXA910 and MXA310 are described as "premium networked array microphone[s] for AV conferencing environments" (Compl. Ex. H at 1; Ex. I at 1). They perform beamforming to create multiple "highly directional pickup lobes" (e.g., 8 lobes for the MXA910) to capture audio from conference participants (Compl. ¶44; Ex. I at 1).
  • The complaint alleges these microphones require external AEC functionality for conferencing applications, and that Shure instructs and encourages customers to use third-party DSPs for this purpose (Compl. ¶¶45, 74). The combination of the Shure microphone (performing beamforming) and the external DSP (performing AEC on the microphone's lobe outputs) allegedly creates an infringing system (Compl. ¶74). A diagram from Shure's user guide illustrates the MXA910 ceiling microphone projecting these distinct lobes onto a conference table (Compl. Ex. I at 2).

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 Shure MXA910 and MXA310 microphone arrays sense acoustic waves in a conference room environment. ¶¶44, 73 col. 9:61-63
performing a beamforming operation to combine the plurality of microphone signals to a plurality of combined signals that is greater in number than one and less in number than the plurality of microphone signals, each of the plurality of combined signals corresponding to a different fixed beam; The Shure microphones' internal processing combines signals from their internal microphone elements to produce a smaller number of discrete, fixed, "highly-directional pickup lobes" (e.g., 8 lobes for the MXA910) as output channels. ¶¶44, 74 col. 9:64 - col. 10:2
performing an acoustic echo cancelation operation on the plurality of combined signals to generate a plurality of combined echo-canceled signals; Shure instructs users to connect the lobe outputs from its microphones to external DSPs (e.g., Biamp Tesira), which then perform AEC on each of those individual lobe signals. ¶¶45, 74, 76; Ex. N at 1 col. 11:1-4
and selecting one or more of the plurality of combined echo-canceled signals for transmission. The external DSPs utilize automatic mixing functionality to select the echo-canceled lobe signal(s) with active speech for transmission to the far end. ¶73; Ex. I at 2 col. 11:5-7

Identified Points of Contention

  • Scope Questions: The core of the dispute may involve divided infringement. Apparatus claim 8 requires "a processor" configured to perform both beamforming and AEC. The complaint alleges these functions are performed by two separate devices: Shure's microphone and a third-party DSP. A central question will be whether these physically separate components can be considered parts of a single infringing "apparatus" or "system" for which Shure is liable. The complaint's allegations of inducement and joint enterprise directly address this issue (Compl. ¶¶75, 76).
  • Technical Questions: A potential point of contention is whether the accused integrated systems perform the claimed steps in the required sequence. The complaint provides evidence, such as an article from partner Biamp, that appears to confirm the alleged operation. The article includes a screenshot of Biamp's software with a specific "SHURE Mics" module designed to take in multiple channels from a Shure microphone and apply processing, which seems to support the allegation that AEC is performed on the "plurality of combined signals" (the lobes) as the patent requires (Compl. Ex. N at 2).

V. Key Claim Terms for Construction

  • The Term: "a processor operably coupled... and configured to... perform a beamforming operation... and perform an acoustic echo cancelation operation" (from independent claim 8)
  • Context and Importance: The definition of "a processor" is critical to the divided infringement issue. If construed to mean a single, unitary component, it could present a challenge to the infringement case, as the accused system uses separate devices for beamforming (Shure mic) and AEC (third-party DSP). If construed more broadly as a "processing system," it may support the plaintiff's theory.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification describes the system in functional blocks. The block diagram in Figure 1 refers to "Processor(s) 110," suggesting the possibility of more than one processor working in concert (’553 Patent, Fig. 1). The patent also states that its illustrative blocks may be implemented with various hardware combinations, including "a plurality of microprocessors" (’553 Patent, col. 4:62-65).
    • Evidence for a Narrower Interpretation: The claim language recites "a processor" in the singular. A defendant might argue that the grammatical structure, which ties both the beamforming and AEC functions to this single antecedent, implies a single, integrated processing unit is required to meet the limitation, even if it is not a single silicon chip.

VI. Other Allegations

  • Indirect Infringement: The complaint places heavy emphasis on indirect infringement. It alleges Shure induces infringement by actively encouraging and instructing customers to combine its microphones with specific third-party DSPs to create the allegedly infringing system. Evidence cited includes press releases announcing partnerships with DSP manufacturers like QSC and Biamp, and technical articles guiding users on system integration (Compl. ¶¶75-76; Exs. J-N). Contributory infringement is also alleged, on the basis that the Shure microphones are a material component of the invention and have no substantial non-infringing use in a conferencing environment without AEC (Compl. ¶76).
  • Willful Infringement: Willfulness is alleged based on Shure's pre-suit knowledge of the ’553 Patent. The complaint asserts that Shure not only knew of the patent but actively challenged its validity in a federal court action and an IPR proceeding. Plaintiff alleges that Shure’s continued sales after the PTAB upheld the validity of the patent claims constitute willful and egregious infringement (Compl. ¶¶47-52, 83).

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

  • A central legal issue will be one of divided infringement: Can Plaintiff prove that Defendant is liable for infringement when the claimed method and apparatus require functions performed by two separate products—Defendant's microphone and a third-party processor? The outcome may depend on the specific facts surrounding the relationship between Defendant and its partners, and the degree of direction and control it provides to end users.
  • A critical procedural question will be the scope of IPR estoppel: Following the PTAB's Final Written Decision confirming the patentability of the challenged claims, to what extent is Defendant precluded from asserting invalidity defenses it raised, or reasonably could have raised, during the IPR? The court's interpretation of this statutory estoppel could significantly narrow the available defenses.
  • The primary technical question will be one of operational correspondence: Does the evidence confirm that the accused integrated systems, as promoted and configured by Defendant and its partners, perform acoustic echo cancellation on the plurality of combined signals (i.e., the fixed lobe outputs), as strictly required by the claims, or is there a functional or sequential variance in the signal processing chain that takes the system outside the claim scope?