PTAB

IPR2019-00502

Murata Mfg Co Ltd v. InerGeTic Ab

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Arrangement for Measuring Angular Velocity
  • Brief Description: The ’349 patent discloses a sensor for detecting rotation, primarily for use in micro-electromechanical systems (MEMS). The sensor includes a central beam with two attached inertia masses, which are excited to produce a first oscillation; when the sensor is rotated, a Coriolis force induces a second, perpendicular oscillation, the magnitude of which is measured to determine the rate of angular velocity.

3. Grounds for Unpatentability

Ground 1: Claims 20, 22-25, and 31 are obvious over Nose

  • Prior Art Relied Upon: Nose (Patent 5,889,208).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Nose, an angular velocity sensor, discloses all limitations of independent claim 20 and the relevant dependent claims. Nose teaches a sensor body formed from a planar substrate with a central support beam fixed at its ends. This beam supports two vibrators (the claimed "inertia mass means") that are excited to oscillate. When subjected to rotation, a Coriolis force induces a second oscillation that is detected by strain gauges (a form of the claimed "means for detecting"). Petitioner asserted Nose's disclosure of driving the vibrators "in anti-phase" meets the final limitation of claim 20. For dependent claims, Nose's symmetrical and identical vibrators were argued to meet the limitations of claims 22 and 23, and its silicon substrate was argued to meet the limitation of claim 31.
    • Motivation to Combine (for §103 grounds): As a single-reference ground, the motivation was inherent. Petitioner contended that Nose taught all elements of the claimed invention. For any minor variations, such as the specific means for exciting the oscillation, Petitioner argued it would have been obvious to a person of ordinary skill in the art (POSITA) to substitute one known drive mechanism disclosed in Nose (e.g., piezoelectric) for another (e.g., electromagnetic coils) to achieve the same predictable function.
    • Expectation of Success (for §103 grounds): A POSITA would have had a high expectation of success because Nose itself teaches the interchangeability of different drive mechanisms and describes a fully functional sensor possessing all the claimed structural and functional elements.

Ground 2: Claims 20, 22-25, and 30-31 are obvious over Nose in view of Yamashita

  • Prior Art Relied Upon: Nose (Patent 5,889,208) and Yamashita (Patent 5,952,572).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground used Nose as the primary reference and supplemented it with Yamashita. Yamashita was cited for its teachings on forming MEMS sensors from a "substantially planar" and "mono-crystalline" silicon substrate, addressing limitations in claims 20 and 30, respectively. Yamashita also explicitly taught using electrostatic force via capacitative plates to excite oscillation, which Petitioner argued was an obvious alternative to the drive mechanisms in Nose and corresponded directly to structures disclosed in the ’349 patent.
    • Motivation to Combine (for §103 grounds): A POSITA would combine these analogous references to achieve predictable benefits. Yamashita's teaching of using flat, polished, single-crystal silicon substrates was known to improve sensor performance (e.g., higher Q-factor, higher sensitivity) and facilitate inexpensive mass production. A POSITA would have been motivated to apply these known fabrication benefits to Nose's sensor design. Furthermore, substituting Yamashita's electrostatic drive would predictably result in a more compact sensor with lower power consumption compared to Nose's electromagnetic coil embodiment.
    • Expectation of Success (for §103 grounds): The combination involved substituting known elements (e.g., electrostatic drive for electromagnetic drive) and applying a known, beneficial material (single-crystal silicon) to a known sensor design, all of which would have yielded predictable improvements in performance and manufacturability.

Ground 3: Claim 33 is obvious over Nose in view of Mattes

  • Prior Art Relied Upon: Nose (Patent 5,889,208) and Mattes (WO 97/33774).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground addressed claim 33, which adds the limitation of mounting the sensor "on a motor vehicle to control deployment of a safety device." Petitioner asserted that Nose taught the base sensor, while Mattes explicitly taught the claimed application. Mattes discloses a method for detecting vehicle rollovers using a "rotation rate sensor" to improve the reliability of activating safety mechanisms like airbags and belt tensioners.
    • Motivation to Combine (for §103 grounds): A POSITA would have been motivated to use Nose's high-detectivity angular velocity sensor as the "rotation rate sensor" in the vehicle safety system described by Mattes. Mattes teaches the desirability of using such sensors to prevent false rollover detections and improve safety. The combination was presented as a straightforward application of a known sensor (Nose) into a known system (Mattes) to achieve an improved, more reliable result.
    • Expectation of Success (for §103 grounds): A POSITA would expect the combination to work for its intended purpose, as Nose provides the precise type of angular velocity data that Mattes requires for its rollover detection algorithm.

  • Additional Grounds: Petitioner asserted that claims 20, 22-25, and 31 are anticipated by Nose, arguing that Nose expressly discloses all claim elements. Petitioner also asserted claim 33 is obvious over the three-way combination of Nose, Yamashita, and Mattes, relying on the same design modification theories.

4. Key Claim Construction Positions

  • "inertia mass means" (claim 20): Petitioner argued this phrase is not a means-plus-function term under §112, ¶ 6 because no function is recited for the "means." It contended the term simply refers to the structure of the inertia masses themselves. Alternatively, if construed as means-plus-function, the function is "to oscillate" and the corresponding structure is the arms and connecting bars that form the masses.
  • "means for exciting a first oscillation..." (claim 20): Petitioner argued this is a means-plus-function term. The recited function is to "excite a first oscillation." The corresponding structures disclosed in the ’349 patent were identified as capacitative plates, thermal films, piezoelectric films, and their equivalents. This construction was central to Petitioner's argument that drive mechanisms in the prior art, like Nose's piezoelectric elements or Yamashita's electrostatic plates, met this limitation.
  • "means for detecting a second oscillation..." (claim 20): Petitioner also argued this is a means-plus-function term. The function is to "detect a second oscillation." The corresponding structures from the ’349 patent were identified as capacitative plates, resonant stress sensors, piezoelectric sensors, piezo-resistive sensors, and equivalents. This construction allowed Petitioner to argue that Nose's piezoresistive strain gauges were a structural equivalent that met this limitation.

5. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 20, 22-25, 30-31, and 33 of the ’349 patent as unpatentable.