PTAB

IPR2019-00683

ClearOne Inc v. Shure Acquisition Holdings Inc

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1. Case Identification

2. Patent Overview

  • Title: Microphone Array Systems
  • Brief Description: The ’493 patent discloses microphone array systems for audio conferencing. The claims are directed to two main embodiments: a circular microphone array with multiple concentric, nested rings of microphones, and a microphone array assembly integrated into a housing designed to replace a standard drop-ceiling tile.

3. Grounds for Unpatentability

Ground 1: Obviousness of Claims 1-7, 9-13, 28-31, 33-34, and 37-40 over Tiete in view of Chan

  • Prior Art Relied Upon: Tiete (a 2014 journal article titled SoundCompass: A Distributed MEMS Microphone Array-Based Sensor for Sound Source Localization) and Chan (a 2007 journal article titled Uniform Concentric Circular Arrays with Frequency-Invariant Characteristics).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Tiete disclosed the core limitations of independent claim 1, including a beamforming microphone array with microphones arranged in four concentric rings on a printed circuit board (PCB) substrate. To the extent Tiete did not explicitly teach certain design parameters, Petitioner asserted Chan supplied the missing elements. Specifically, Chan taught the well-known principle of designing concentric circular arrays where ring diameters are based on the desired frequency range, and that adding more rings and microphones improves performance (e.g., signal-to-noise ratio and bandwidth).
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine the teachings of Chan with Tiete’s system to optimize its performance. Tiete itself taught that for sensor arrays, "the bigger, the better," motivating a POSITA to look to established design principles like those in Chan to expand Tiete's four-ring array to the claimed seven rings (claim 7) or increase the microphone count to the claimed range of 113-120 (claims 9-10). Chan's teachings were presented as universally applicable principles for acoustic beamforming arrays like Tiete's.
    • Expectation of Success: A POSITA would have a high expectation of success because both references taught similar concentric circular microphone arrays. Applying Chan's mathematical design principles to modify the scale (number of rings and microphones) of Tiete's physical embodiment was argued to be a straightforward and predictable design choice.

Ground 2: Obviousness of Claims 8, 14-16, 32, and 35-36 over Tiete and Chan in view of Chou, Sawa, Beaucoup, and/or Meyer

  • Prior Art Relied Upon: Tiete and Chan as the base combination, supplemented by Chou (a 1995 conference paper on beamforming), Sawa (Patent 9,826,211), Beaucoup (Application # 2003/0118200), and/or Meyer (Patent 8,903,106).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground addressed dependent claims reciting additional features. Petitioner argued it would have been obvious to add these known features to the base Tiete/Chan array. Chou taught using "harmonically nested" subarrays to cover a large frequency range (claim 8). Sawa taught a system that generates multiple, simultaneous audio outputs for different sound sources (claim 14). Beaucoup taught using LEDs as "external indicators" to show the operating mode (e.g., mute, presentation) of a conferencing system (claim 15). Sawa also taught using multiple peripheral PCBs arranged radially around a central point to build a larger array (claim 16). Finally, Meyer taught adding a "center microphone" to a circular array to improve vertical beamforming and reduce aliasing (claim 32).
    • Motivation to Combine: The motivation was to improve the base Tiete/Chan array by incorporating known, advantageous features from the art. For example, a POSITA would incorporate Chou's harmonic nesting for more efficient frequency coverage, Sawa's multiple outputs to allow individual analysis of sound sources, Beaucoup's status indicators for user convenience, and Meyer's center microphone to enhance audio quality.
    • Expectation of Success: A POSITA would expect success because these were well-known techniques and components being added to a conventional array design. The proposed modifications were presented as predictable integrations of desirable functionalities common in the field of audio conferencing.

Ground 3: Obviousness of Claims 17, 18, 21, and 23-26 over Graham

  • Prior Art Relied Upon: Graham (Application # 2015/0078582).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground targeted the ceiling tile claims. Petitioner argued that Graham disclosed nearly all limitations of independent claim 17 by teaching a beamforming microphone array integrated into a ceiling tile for a drop-ceiling mounting configuration. Graham's tile was described as having a sound-permeable front face and being sized to replace a standard ceiling tile, with microphones embedded to "disguise the... array as a standard ceiling tile." Petitioner contended that Graham's disclosure of using "metals" for the housing would have obviously suggested lightweight aluminum (claim 21) to a POSITA, as it is a common, lightweight metal used for such components. Graham also explicitly taught creating larger arrays spanning multiple ceiling tiles (claim 26).
    • Motivation to Combine: This ground relied on a single reference, obviating the need for a motivation to combine. The argument was that Graham's disclosure was so similar to the claimed invention that the claims were obvious from Graham alone.
    • Expectation of Success: Not applicable for a single-reference ground.

  • Additional Grounds: Petitioner asserted a fourth ground that claims 19-20, 22, and 27 are obvious over Graham in view of Sawa, Berry (WO 2011/104501), or Beaucoup. This ground argued for adding a "control box" (from Sawa), a "honeycomb core" (from Berry), and an "external indicator" (from Beaucoup) to Graham's ceiling tile array.

4. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1-40 of Patent 9,565,493 as unpatentable.