PTAB

IPR2024-00105

InductEV Inc v. WiTricity Corp

Key Events

Petition

petition

Title: Foreign Object Detection in Wireless Energy Transfer Systems
Brief Description: The ’184 patent discloses systems for wireless energy transfer that incorporate a foreign object debris (FOD) detection capability. The technology uses one or more magnetic field sensors to detect perturbations in the oscillating magnetic field generated between coupled resonators, enabling the system to halt or limit power transfer when foreign objects are detected.

Prior Art Relied Upon: Fells (Application # 2010/0084918).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued that Fells taught a complete wireless power system with all the core features of independent claim 1. Fells described a wireless power supply using a resonator (a "tank circuit" comprising a primary coil and capacitor) to generate an oscillating magnetic field. This system included a "sense circuit" that functions as the claimed foreign object detection system. Fells explicitly disclosed that this sense circuit could be a proximity detector, such as a Hall effect sensor or an inductive proximity sensor, which are types of magnetic field sensors. This sensor is coupled with readout circuitry to detect changes in the magnetic field, indicating the presence of an object. Fells also taught verifying the absence of foreign objects both before initiating power transfer (claim 8) and during the power transfer process, with the detection system being part of the power supply itself (claim 11).
- Motivation to Combine (for §103 grounds): This ground was presented as an obviousness challenge, but the arguments asserted that Fells directly taught all limitations. No combination of references was required.

Prior Art Relied Upon: Fells (Application # 2010/0084918) and Cook (Application # 2009/0299918).
Core Argument for this Ground:
- Prior Art Mapping: This ground addressed claims reciting a "vehicle" and related method steps. Petitioner contended that Fells taught the foundational FOD and wireless charging system for a generic "portable device," while Cook taught a highly analogous wireless charging system specifically for an "automobile." The combined teachings would result in a wireless charging station for a vehicle that performs FOD checks before the vehicle arrives, after it is positioned, and during charging, as recited in the dependent and method claims.
- Motivation to Combine: A POSITA would combine Fells’ FOD system with Cook’s vehicle charging application to improve the safety and reliability of electric vehicle charging. Unlike small portable devices, vehicles are charged in less controlled environments (e.g., garages, parking lots) where the risk of foreign debris is higher, making a robust FOD system a desirable and predictable improvement.
- Expectation of Success: A POSITA would have a high expectation of success, as both Fells and Cook disclosed systems based on the same well-understood principles of resonant magnetic coupling and used analogous components (LC resonators for the transmitter and receiver).

Prior Art Relied Upon: Fells (Application # 2010/0084918) and Ono (Patent 6,075,433).
Core Argument for this Ground:
- Prior Art Mapping: Claim 12 adds the limitation of an "enclosure housing" that integrates the wireless energy transfer source and the FOD system. Petitioner argued that while Fells’ own diagrams suggested an integrated enclosure, Ono explicitly taught a non-contact power supply where the primary power coil and a foreign object detector coil are mounted together inside a "primary enclosure."
- Motivation to Combine: A POSITA would be motivated to place the components of Fells’ system within an enclosure as taught by Ono. This was a well-known and obvious design choice to achieve the predictable benefits of protecting sensitive electronic components from environmental contaminants, physical damage, and electrical shorts, while also ensuring user safety.

Prior Art Relied Upon: Fells (Application # 2010/0084918), Cook (Application # 2009/0299918), and Wang Thesis (a 2004 dissertation).
Core Argument for this Ground:
- Prior Art Mapping: Claim 13 required the system to deliver more than 3.3 kW of power. While Fells and Cook did not specify power levels, the Wang Thesis provided a detailed "design methodology," including specific formulas, for engineering an inductively coupled vehicle charging system to achieve a desired power output. As a proof of concept, Wang Thesis detailed the design of a system that delivers 30 kW.
- Motivation to Combine: A POSITA designing the vehicle charging system of Fells and Cook would be motivated to provide power greater than 3.3 kW. This power level was consistent with "Level 2" charging standards of the era and was necessary to charge an electric vehicle in a reasonable timeframe (e.g., overnight). Wang Thesis provided the explicit engineering roadmap to achieve this predictable power-scaling result.

Petitioner argued against discretionary denial under 35 U.S.C. §325(d), asserting that key prior art references, specifically Ono and Wang Thesis, were never presented to or considered by the USPTO during prosecution.
Petitioner contended that discretionary denial under Fintiv was unwarranted because, at the time the petition was filed, no trial date had been scheduled in the co-pending district court litigation.

Petitioner requests institution of an inter partes review and cancellation of claims 1-13 and 16 of the ’184 patent as unpatentable.