DCT

6:24-cv-00437

NuCurrent Inc v. OnePlus Technology Shenzhen Co Ltd

I. Executive Summary and Procedural Information

Parties & Counsel:
- Plaintiff: NuCurrent, Inc. (Delaware)
- Defendant: OnePlus Technology (Shenzhen) Co., Ltd. (China)
- Plaintiff’s Counsel: Global IP Law Group, LLC
Case Identification: 6:24-cv-00437, W.D. Tex., 08/26/2024
Venue Allegations: Plaintiff alleges venue is proper because Defendant is a foreign corporation, making venue proper in any judicial district under 28 U.S.C. § 1391(c)(3). The complaint also asserts that Defendant has a regular and established place of business in the district in the form of a national repair center and has committed acts of infringement there.
Core Dispute: Plaintiff alleges that Defendant’s smartphones and wireless chargers infringe eight U.S. patents related to multi-layer, multi-turn inductor structures designed for high-efficiency wireless power transfer.
Technical Context: The technology at issue addresses inefficiencies in wireless charging coils, primarily the "skin effect," by using layered conductor structures to improve the quality factor and overall performance of wireless power systems.
Key Procedural History: The complaint does not mention any prior litigation, Inter Partes Review (IPR) proceedings, or licensing history related to the patents-in-suit.

Case Timeline

Date	Event
2009-03-09	Earliest Priority Date for all Patents-in-Suit
2013-12-17	U.S. Patent No. 8,610,530 Issues
2014-04-08	U.S. Patent No. 8,692,641 Issues
2014-04-15	U.S. Patent No. 8,698,590 Issues
2014-09-02	U.S. Patent No. 8,823,481 Issues
2014-09-02	U.S. Patent No. 8,823,482 Issues
2021-07-09	Accused OnePlus AIRVOOC 50W Charger Certification Date
2022-05-17	U.S. Patent No. 11,336,003 Issues
2022-10-18	U.S. Patent No. 11,476,566 Issues
2023-12-07	Accused OnePlus 12 Smartphone Certification Date
2024-02-27	U.S. Patent No. 11,916,400 Issues
2024-08-26	Complaint Filing Date

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 8,610,530 - "Multi-layer-multi-turn structure for tunable high efficiency inductors"

Issued: December 17, 2013

The Invention Explained

Problem Addressed: The patent family addresses the technical problem of the "skin effect" in electrical conductors at high frequencies (Compl. ¶15; ’003 Patent, col. 2:6-14). This phenomenon concentrates alternating current near the conductor's surface, increasing its effective resistance, causing energy loss, and reducing the efficiency (or "quality factor") of inductors used for wireless power transfer (’003 Patent, col. 1:56-64).
The Patented Solution: The invention proposes an inductor constructed from a multi-layer wire, comprising multiple conductive layers separated by insulating layers (’530 Patent, Abstract). This layered structure creates significantly more surface area for the current to flow compared to a solid wire of the same size, thereby mitigating the skin effect, lowering resistance, and increasing the inductor's quality factor and overall efficiency (’003 Patent, col. 4:25-44).
Technical Importance: This approach enabled the design of more compact and efficient coils, a critical development for integrating wireless charging into space-constrained mobile devices like smartphones (Compl. ¶15).

Key Claims at a Glance

The complaint asserts independent claims 1 and 25 ('530 Patent, Compl. ¶35).
The essential elements of independent claim 1 include:
- An inductor for use in an electrical circuit
- comprising a multi-layer, multi-turn structure
- the structure comprising a plurality of conductor layers, an insulator layer separating each of the conductor layers, and at least one connector connecting two of the conductor layers
- wherein the inductor is constructed to have an electrical resistance that is reduced when an electrical signal is induced in the inductor at a radio frequency
The complaint reserves the right to assert additional claims, including dependent claims (Compl. ¶37).

U.S. Patent No. 8,692,641 - "Multi-layer-multi-turn high efficiency inductors with cavity structures"

Issued: April 8, 2014

The Invention Explained

Problem Addressed: In addition to the skin effect described for the ’530 Patent, this related invention addresses parasitic capacitance that can arise between the multiple conductive layers in a stacked structure (’641 Patent, Abstract). This unwanted capacitance can limit the inductor's performance at higher frequencies by lowering its self-resonance frequency.
The Patented Solution: The patented solution introduces a "cavity" within the inductor structure (’641 Patent, col. 2:38-41). This cavity, which may be an air gap or a region filled with a low-dielectric material, physically separates the conductive layers more effectively, reducing parasitic capacitance and allowing the inductor to operate efficiently at higher frequencies (’641 Patent, col. 23:41-50).
Technical Importance: By providing a method to control parasitic capacitance, the invention allowed for the design of high-quality-factor inductors that could perform effectively across a wider and higher range of operating frequencies (Compl. ¶15).

Key Claims at a Glance

The complaint asserts independent claims 1, 21, and 31 ('641 Patent, Compl. ¶35).
The essential elements of independent claim 1 are similar to claim 1 of the ’530 Patent, with the key addition of:
- wherein the inductor comprises a cavity therewithin
The complaint reserves the right to assert additional claims (Compl. ¶37).

U.S. Patent No. 8,698,590 - "Method for operation of multi-layer-multi-turn high efficiency inductors with cavity structure"

Issued: April 15, 2014 (Compl. ¶18)
Technology Synopsis: This patent focuses on the methods of operating the multi-layer, multi-turn inductor structures with cavities, as described for the ’641 Patent. It claims the steps of using these structures to achieve high-efficiency wireless power and data transfer by managing both resistive losses and parasitic capacitance.
Asserted Claims: Independent claims 1 and 17 are asserted (Compl. ¶35).
Accused Features: The operation of the inductor structures within the Accused OnePlus Devices for wireless charging is alleged to infringe (Compl. ¶24).

U.S. Patent No. 8,823,481 - "Multi-layer-multi-turn high efficiency inductors for electrical circuits"

Issued: September 2, 2014 (Compl. ¶19)
Technology Synopsis: This patent claims the multi-layer, multi-turn inductor structure itself, designed for general use in electrical circuits. The claims focus on the physical arrangement of conductive and insulating layers to reduce electrical resistance at radio frequencies.
Asserted Claims: Independent claims 1 and 17 are asserted (Compl. ¶35).
Accused Features: The inductor structures within the Accused OnePlus Devices are alleged to embody the claimed invention (Compl. ¶24).

U.S. Patent No. 8,823,482 - "Systems using multi-layer-multi-turn high efficiency inductors"

Issued: September 2, 2014 (Compl. ¶20)
Technology Synopsis: This patent focuses on systems that incorporate the multi-layer, multi-turn inductor technology. The claims are directed to complete systems, such as wireless power transmitters or receivers, that use the patented inductor structure to achieve high-efficiency operation.
Asserted Claims: Independent claims 1 and 18 are asserted (Compl. ¶35).
Accused Features: The Accused OnePlus Devices, as complete wireless charging systems, are alleged to infringe (Compl. ¶24).

U.S. Patent No. 11,336,003 - "Multi-layer, multi-turn inductor structure for wireless transfer of power"

Issued: May 17, 2022 (Compl. ¶21)
Technology Synopsis: This more recent patent in the family claims systems for wireless power transfer incorporating the multi-layer, multi-turn inductor structure. The claims specify a first device with a transmitting antenna and a second device with a receiving antenna that uses the patented structure, which includes first and second conductive layers connected in parallel (’003 Patent, col. 36:1-68).
Asserted Claims: Independent claims 1, 8, and 30 are asserted (Compl. ¶35).
Accused Features: The system of a OnePlus charger (first device) and a OnePlus smartphone (second device) is alleged to infringe (Compl. ¶¶ 26, 30).

U.S. Patent No. 11,476,566 - "Multi-layer-multi-turn structure for high efficiency wireless communication"

Issued: October 18, 2022 (Compl. ¶22)
Technology Synopsis: This patent claims the multi-layer, multi-turn structure with a focus on its application in wireless communication. The claims cover the physical structure of alternating conductive and insulator layers connected in a way that reduces resistance at a predetermined frequency (’566 Patent, Abstract).
Asserted Claims: Independent claims 19 and 22 are asserted (Compl. ¶35).
Accused Features: The inductor structures within the Accused OnePlus Devices are alleged to embody the claimed invention for wireless power transfer, which is a form of wireless communication (Compl. ¶24).

U.S. Patent No. 11,916,400 - "Multi-layer-multi-turn structure for high efficiency wireless communication"

Issued: February 27, 2024 (Compl. ¶23)
Technology Synopsis: This patent, like the ’566 Patent, claims the multi-layer, multi-turn inductor structure in the context of high-efficiency wireless communication. The claims focus on the physical arrangement of conductive and insulating layers that enables the efficient transfer of energy and/or data at various magnetic coupling frequencies (’400 Patent, Abstract).
Asserted Claims: Independent claims 1 and 16 are asserted (Compl. ¶35).
Accused Features: The inductor structures within the Accused OnePlus Devices are alleged to embody the claimed invention (Compl. ¶24).

III. The Accused Instrumentality

Product Identification

The complaint identifies the OnePlus Warp Charge 50 Wireless Charger (also referred to as the OnePlus AIRVOOC 50W Wireless Charger) and the OnePlus 12 smartphone as the "Accused OnePlus Devices" (Compl. ¶¶ 26, 28, 30).

Functionality and Market Context

The Accused OnePlus Devices are alleged to be compliant with the Wireless Power Consortium's Qi wireless charging specification (Compl. ¶25). The complaint provides a screenshot from the WPC's product database showing the OnePlus AIRVOOC 50W Wireless Charger was certified as a Qi-compliant transmitting (PTx) device on July 9, 2021 (Compl. ¶26, p. 10).
The OnePlus 12 smartphone is alleged to function as both a receiving (PRx) device, capable of being wirelessly charged, and a transmitting (PTx) device through its "reverse wireless charging" functionality (Compl. ¶¶ 28-30). A second screenshot from the WPC database shows the OnePlus 12 smartphone was certified as a Qi-compliant receiving device on December 7, 2023 (Compl. ¶30, p. 12).
Plaintiff alleges that these products, which are sold and offered for sale in the United States, contain the inductors, electrical circuits, and systems that practice the claimed inventions (Compl. ¶¶ 9, 24).

IV. Analysis of Infringement Allegations

The complaint alleges that Exhibit 1 contains claim charts illustrating infringement, but this exhibit was not filed with the complaint (Compl. ¶36). The narrative theory of infringement is that the Accused OnePlus Devices contain inductors that comprise the multi-layer, multi-turn ("MLMT") structures central to the patents-in-suit, thereby providing increased wireless charging efficiency (Compl. ¶¶ 15, 24).

Identified Points of Contention:
- Structural Identity Questions: The complaint's infringement theory rests on the assertion that the inductors inside the accused products have a specific multi-layer, multi-turn construction. A primary technical question will be what evidence demonstrates that the accused products' inductors are in fact MLMT structures as claimed, rather than alternative technologies like conventional Litz wire which also address the skin effect. The complaint's reliance on the products' Qi-compliance does not, on its face, establish the use of any specific patented inductor structure, as the Qi standard governs interoperability protocols rather than mandating specific component designs.
- Scope Questions: For patents like the ’641 Patent that require additional specific features such as a "cavity," a key question is whether the general allegations of infringement are sufficient. The complaint does not specifically identify a "cavity" or any corresponding feature in the accused products, which may create a point of contention regarding whether infringement of those claims has been plausibly alleged.

V. Key Claim Terms for Construction

The Term: "multi-layer, multi-turn structure"
Context and Importance: This term is the core of the asserted inventions and appears in the independent claims of numerous patents-in-suit. Its construction will be central to the dispute, as it defines the boundary between the patented technology and prior art or alternative inductor designs. Practitioners may focus on this term because the infringement case depends on whether the coils in the accused products fall within its scope.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification describes the structure broadly as comprising "layers of conducting material alternating with layers of non-conducting material" (’003 Patent, col. 4:29-32). This language could support a construction that covers a wide range of stacked-conductor arrangements.
- Evidence for a Narrower Interpretation: The patents provide specific examples and figures showing the structure implemented with planar conductive traces on a printed circuit board (PCB) (’003 Patent, Fig. 19). This could support a narrower construction limited to such planar or PCB-based embodiments, potentially excluding other types of multi-conductor wires.
The Term: "cavity"
Context and Importance: This term is a key limitation in several asserted patents, including the ’641 and ’590 patents. A finding of infringement for these patents will likely require the accused products to contain a structure meeting this definition. Practitioners may focus on this term because the complaint lacks specific allegations identifying such a feature in the accused products.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The term could be construed broadly to mean any void or pocket of air within the inductor's structure, which might occur incidentally in some manufacturing processes.
- Evidence for a Narrower Interpretation: The specification of the parent application for the '641 patent discusses the cavity as a feature introduced to "reduce the substrate effect" and parasitic capacitance, and shows it as a deliberately created region within the inductor volume (’641 Patent, Abstract; col. 23:41-47). This may support a narrower construction requiring an intentionally designed void or a space filled with a specific low-permittivity material, rather than incidental air gaps.

VI. Other Allegations

Indirect Infringement: The complaint does not include counts for indirect or contributory infringement. However, it alleges that Defendant's user manuals instruct users on how to operate the reverse wireless charging feature, a fact that could potentially support a future allegation of induced infringement (Compl. ¶29).
Willful Infringement: The complaint does not contain an explicit allegation of willful infringement, nor does it allege that Defendant had pre-suit knowledge of the patents-in-suit.

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

A core issue will be one of structural proof: What is the actual physical construction of the inductors inside the accused OnePlus products? The case will likely depend on expert analysis and discovery to determine whether these components embody the specific multi-layer, multi-turn configurations required by the claims, or if they utilize an alternative, non-infringing design.
A key pleading and claim scope question will be one of feature presence: Does the complaint provide a plausible basis to infer that every limitation of the asserted claims is met, particularly for patents requiring specific elements like a "cavity" that are not explicitly identified in the accused products? The resolution of this question will determine the scope of patents that remain in the case.
A central legal question will be one of functional equivalence vs. structural identity: Given that other technologies exist to solve the "skin effect" problem, the case may turn on whether the accused devices achieve high efficiency through the patented multi-layer structure, or through an alternative method that is structurally and functionally distinct from what is claimed.