PTAB

IPR2025-00842

Suzhou Mojawa Intelligent Electronic Co Ltd v. Shenzhen Shokz Co Ltd

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Loudspeaker Apparatus
  • Brief Description: The ’084 patent discloses a modularly designed bone conduction headphone apparatus featuring an ear hook, a core housing for an earphone core, and a separate circuit housing for a control circuit or battery.

3. Grounds for Unpatentability

Ground 1: Obviousness over Li and Fujita - Claims 1 and 11 are obvious over Li in view of Fujita.

  • Prior Art Relied Upon: Li (CN Application # 107454492A) and Fujita (WO 2008/007666).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Li disclosed the overall structure of a bone conduction earphone, including an ear hook assembly connecting a speaker housing and a circuit/battery housing. However, Li lacked specific details on the bone conduction speaker's vibration mechanism. Fujita allegedly supplied these missing details by teaching a bone conduction speaker with a multilayer piezoelectric element that generates vibrations and a cushion that transmits the vibrations to the user's head. Petitioner asserted that the combination meets all limitations of claim 1, including the driving force being not parallel to a normal line of the housing panel, as shown in Fujita's figures.
    • Motivation to Combine: A POSITA would combine Li and Fujita to improve Li's general earphone structure with Fujita's detailed and efficient bone conduction speaker design. Both references are in the same field of bone conduction audio devices and address similar design objectives. A POSITA reading Li would have looked to contemporaneous references like Fujita for specific implementation details of the vibration mechanism.
    • Expectation of Success: A POSITA would have had a reasonable expectation of success because combining the teachings involved applying a known speaker technology (Fujita) to a known earphone structure (Li). The interchangeability of such components was well-understood in the art, and the combination would yield predictable results.

Ground 2: Obviousness over Li, Fujita, and Fukuda - Claims 12-15 are obvious over the combination of Li and Fujita, further in view of Fukuda.

  • Prior Art Relied Upon: Li (CN Application # 107454492A), Fujita (WO 2008/007666), and Fukuda (Patent 9,253,563).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground built upon the Li-Fujita combination and argued for replacing Fujita’s piezoelectric vibration mechanism with Fukuda's magnetic circuit system. Fukuda disclosed a bone conduction speaker using a voice coil and a magnetic circuit system. Petitioner contended this substitution would result in a device meeting the limitations of claims 12-15, which relate to the transmission connection between the earphone core and housing panel (claim 12), the angle of the driving force (claim 13), and the use of a coil and magnetic circuit system (claim 14).
    • Motivation to Combine: A POSITA would have been motivated to substitute Fukuda’s magnetic driver for Fujita’s piezoelectric driver to achieve superior performance. Petitioner argued that magnetic circuit systems were known to provide higher quality sound and simpler construction than piezoelectric drivers. Fukuda explicitly taught an improved, simple, and low-cost magnetic system for bone conduction speakers, providing a clear reason to incorporate it into the Li-Fujita design.
    • Expectation of Success: Success was predictable due to the known interchangeability of different driver types in speaker design. A POSITA would have understood that replacing one type of vibration mechanism with another was a routine design choice to improve performance, and both Fukuda's and Fujita's systems were designed for the same purpose in bone conduction speakers.

Ground 3: Obviousness over Li, Fujita, Wang, Xu, and Nielsen - Claims 16-20 are obvious over the combination of Li and Fujita, further in view of Wang, Xu, and Nielsen.

  • Prior Art Relied Upon: Li (CN Application # 107454492A), Fujita (WO 2008/007666), Wang (CN Utility Model # 205356672U), Xu (CN Utility Model # 205017577U), and Nielsen (WO 2009/086838).

  • Core Argument for this Ground:

    • Prior Art Mapping: Claims 16-20 recite specific features of a magnetic circuit component, including multiple magnetic units and magnetically conductive units arranged to create a strong magnetic field in a gap. Petitioner argued that Wang, Xu, and Nielsen collectively disclosed these specific structural arrangements. For example, Wang taught a magnetic circuit with multiple magnetic steels and pole cores, while Xu disclosed an arrangement of inner and outer annular magnets to increase magnetic flux density in the gap. Nielsen taught adding a conductive layer to reduce inductive reactance.
    • Motivation to Combine: A POSITA seeking to build an improved bone conduction speaker based on the Li-Fujita framework would have looked to references like Wang, Xu, and Nielsen for state-of-the-art magnetic circuit designs. These references taught specific improvements in magnetic circuit efficiency, magnetic field strength, and overall performance. The motivation was to combine these known, compatible improvements to create a more powerful and efficient speaker.
    • Expectation of Success: The combination was predictable because Wang, Xu, and Nielsen all operate in the same field of loudspeaker magnet systems. A POSITA would have understood that the disclosed components were interoperable and could be combined using standard engineering practices to achieve the cumulative benefits of a stronger, more efficient magnetic field.

  • Additional Grounds: Petitioner asserted additional obviousness challenges, including grounds based on Li, Fujita, and Asaka (for claims 2-6 related to wiring and fixed sleeves) and on Li, Fujita, and Numata (for claims 7-10 related to plug and socket connection features).

4. Key Claim Construction Positions

  • Petitioner argued that the term in claim 5, "the second wiring channel includes a second wiring groove and a second wiring hole connecting the second wiring groove and the outer end surface of the first plug end," contains a clear typographical error.
  • It was proposed that "first plug end" should be construed to mean "second plug end." This construction is necessary for claim coherence, as the preceding limitations address the "first" plug end, and parallel structure dictates that this limitation addresses the corresponding "second" plug end.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-10 and 12-20 of the ’084 patent as unpatentable.