DCT
2:25-cv-00779
NuCurrent Inc v. Hong Kong Ugreen Ltd
Key Events
Amended Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: NuCurrent, Inc. (Delaware)
- Defendant: Hong Kong Ugreen Limited and Ugreen Group Ltd. (Hong Kong)
- Plaintiff’s Counsel: Global IP Law Group, LLC
- Case Identification: 2:25-cv-00779, E.D. Tex., 11/10/2025
- Venue Allegations: Venue is alleged to be proper under 28 U.S.C. § 1391(c)(3), which applies to defendants not resident in the United States.
- Core Dispute: Plaintiff alleges that Defendant’s Qi2-compliant wireless chargers infringe four U.S. patents related to dynamic tuning, power level control, and foreign object detection in wireless power transfer systems.
- Technical Context: The technology at issue involves wireless charging for consumer electronics, specifically relating to the Qi2 standard, which aims to improve the efficiency and interoperability of magnetic wireless chargers.
- Key Procedural History: The complaint alleges that Plaintiff provided Defendant with repeated pre-suit notice of the patents-in-suit beginning in April 2024, including letters with claim charts and multiple offers to license the patents on RAND terms, which Defendant allegedly declined.
Case Timeline
| Date | Event |
|---|---|
| 2012-01-01 | Ugreen Group Limited established |
| 2020-01-03 | Earliest Priority Date for ’084 Patent |
| 2020-04-30 | Earliest Priority Date for ’970 Patent |
| 2021-01-28 | Earliest Priority Date for ’573 Patent |
| 2021-02-10 | Earliest Priority Date for ’470 Patent |
| 2023-09-25 | Ugreen submitted trademark "specimen" to USPTO |
| 2024-04-11 | NuCurrent first contacted Ugreen regarding alleged infringement |
| 2024-05-01 | NuCurrent sent follow-up contact to Ugreen |
| 2024-05-03 | NuCurrent's notice letter delivered to Ugreen |
| 2024-07-26 | Ugreen Group Limited listed on Shenzhen Stock Exchange |
| 2024-12-31 | U.S. Patent No. 12,184,084 Issued |
| 2025-01-23 | NuCurrent sent follow-up contact to Ugreen |
| 2025-02-20 | NuCurrent sent follow-up contact to Ugreen |
| 2025-04-08 | U.S. Patent No. 12,272,970 Issued |
| 2025-07-01 | UGREEN announced first Qi 2.2 certified power bank |
| 2025-10-07 | U.S. Patent No. 12,438,573 Issued |
| 2025-10-21 | Alleged earliest date of Defendant's awareness of ’573 Patent |
| 2025-11-03 | U.S. Patent No. 12,463,470 Issued |
| 2025-11-10 | Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 12,184,084: "Systems and methods for dynamically tuning a wireless power transfer system" (Issued Dec. 31, 2024)
The Invention Explained
- Problem Addressed: The efficiency of wireless power transfer is sensitive to "disturbances" such as varying distance between charging coils, changes in temperature, and altered electrical impedances, which can arise during normal use ('084 Patent, col. 1:61-col. 2:2).
- The Patented Solution: The patent describes a system that employs a "dynamic tuning controller" to actively manage the power transfer process. This controller collects data from various sensors (e.g., temperature, voltage, current) and, based on this information, adjusts "forward gain elements" of the system, such as operating frequency or the configuration of capacitor banks, to compensate for disturbances and maintain optimal power transfer efficiency ('084 Patent, Abstract; col. 2:26-40). The system architecture shown in Figure 8 illustrates a controller receiving multiple sensor inputs to manage tuning elements on both the transmitter and receiver sides ('084 Patent, Fig. 8).
- Technical Importance: This approach enables a wireless charging system to adapt to real-world operating conditions in real time, which may support more reliable and efficient charging performance ('084 Patent, col. 2:5-12).
Key Claims at a Glance
- The complaint asserts independent claim 1 (Compl. ¶51).
- Essential elements of independent claim 1 include:
- A voltage regulator to produce a supply voltage signal.
- An inverter to produce a first AC signal with a configurable frequency and power level based on the supply voltage.
- A capacitor circuit with a "bank of two or more capacitors" operable to tune the first AC signal and produce a second AC signal.
- A transmission antenna to produce a wireless power signal from the second AC signal.
- A controller configured to define the frequency, voltage level, and capacitor configuration state by providing control signals to the respective components ('084 Patent, col. 37:58-col. 38:44).
- The complaint also asserts dependent claims 3-13, 21, and 22 and reserves the right to assert additional claims (Compl. ¶¶51, 53).
U.S. Patent No. 12,272,970: "Operating frequency based power level altering in extended range wireless power transmitters" (Issued Apr. 8, 2025)
The Invention Explained
- Problem Addressed: Traditional wireless chargers have a very limited range (e.g., 3-5 mm). Extending this range requires more sophisticated power control, especially when using common external power sources like USB Power Delivery (USB-PD) adapters, which can provide multiple different voltage levels ('970 Patent, col. 1:50-col. 2:23).
- The Patented Solution: The patent claims a method where the wireless transmitter coordinates with an external power supply. The transmitter's controller first sends a request for the external supply to change its voltage (e.g., from 5V to 9V). After detecting that the voltage level has changed, the controller then causes the transmitter's own operating frequency to change. This sequential process of coordinating a voltage change with a subsequent frequency shift allows the system to adjust its power output granularly ('970 Patent, Abstract; col. 28:1-20).
- Technical Importance: This method allows a wireless transmitter to leverage the capabilities of modern, off-the-shelf external power supplies to achieve extended-range charging, potentially reducing the cost and complexity of the transmitter itself by outsourcing a portion of the voltage regulation function ('970 Patent, col. 3:20-33).
Key Claims at a Glance
The complaint asserts independent claim 1 (Compl. ¶51).
Essential elements of independent claim 1 include:
- A power-supply interface for receiving a supply voltage from an external source.
- A power conditioning system to produce an AC signal.
- A controller configured to:
- Send a request to the external power supply to change its voltage level.
- Detect that the external supply has changed its voltage level.
- After said detection, cause the configurable frequency of its drive signal to be changed ('970 Patent, col. 27:58-col. 28:20).
The complaint also asserts dependent claims 3-7, 11, 12, 14, 16, and 18-25, and reserves the right to assert additional claims (Compl. ¶¶51, 53).
Multi-Patent Capsule: U.S. Patent No. 12,438,573, "Wireless Power Transfer System With Data Versus Power Priority Optimization" (Issued Oct. 7, 2025)
- Technology Synopsis: This patent addresses the technical trade-off between transferring high power and maintaining reliable data communication in a wireless system. The invention describes a transmitter that determines the coupling quality with a receiver, receives a "selected power mode" from the receiver based on that coupling, and then operates according to that mode to optimize for either power delivery or data integrity ('573 Patent, Abstract; col. 4:26-44).
- Asserted Claims: Independent claims 1 and 29 are asserted (Compl. ¶51).
- Accused Features: The complaint alleges that the "Accused Ugreen Qi2.2.1 Wireless Chargers" infringe this patent (Compl. ¶51).
Multi-Patent Capsule: U.S. Patent No. 12,463,470, "Slotted Foreign Object Detection During Wireless Power Transfer" (Issued Nov. 4, 2025)
- Technology Synopsis: This patent relates to Foreign Object Detection (FOD), a safety feature in wireless charging. The invention describes a method where the transmitter temporarily pauses power transmission for a brief "slot" of time to perform an FOD process, such as measuring impedance or quality factor to detect foreign metallic objects that could otherwise overheat ('470 Patent, Abstract; Claim 1).
- Asserted Claims: Independent claim 1 is asserted (Compl. ¶51).
- Accused Features: The complaint alleges that the "Accused Ugreen Qi2.2.1 Wireless Chargers" infringe this patent (Compl. ¶51).
III. The Accused Instrumentality
- Product Identification: The complaint identifies the accused products as the "Accused Ugreen Qi2 Wireless Chargers" and "Accused Ugreen Qi2.2.1 Wireless Chargers" (Compl. ¶¶31, 35, 41).
- Functionality and Market Context: The accused products are accessories that wirelessly charge mobile devices and are alleged to operate in compliance with the Qi2 and Qi2.2.1 Specifications from the Wireless Power Consortium ("WPC") (Compl. ¶¶31, 35). The complaint lists multiple specific Ugreen models sold through various online and retail channels, including Amazon, AliExpress, and Best Buy (Compl. ¶¶24-29). The complaint includes photographs of an accused "2-in-1 Magnetic Wireless Charger," showing the device itself and its packaging, which identifies it as a Qi2-certified product (Compl. ¶¶32-33). Another set of photographs shows an example Qi2.2.1 charger and its packaging (Compl. ¶36).
IV. Analysis of Infringement Allegations
The complaint does not include detailed claim charts but alleges that the Accused Ugreen Qi2 and Qi2.2.1 Wireless Chargers practice each limitation of the asserted claims by virtue of their compliance with the relevant WPC specifications (Compl. ¶¶42, 52).
’084 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a voltage regulator that is operable to... produce the supply voltage signal... | The accused chargers are alleged to contain power regulation circuitry to provide a controlled supply voltage for wireless power transmission. | ¶31, ¶51 | col. 9:43-50 |
| an inverter that is operable to... produce a first AC signal having the configurable frequency and a configurable power level... | The accused chargers allegedly convert DC power to a high-frequency AC signal to drive the transmission coil, a core function of a wireless charger. | ¶31, ¶51 | col. 14:3-11 |
| a capacitor circuit that comprises a bank of two or more capacitors and is operable to... tune the first AC signal... | Qi2-compliant chargers are alleged to use configurable capacitor arrays to tune the resonant circuit and optimize power transfer under varying conditions. | ¶31, ¶51 | col. 21:35-47 |
| a transmission antenna that is operable to... produce a wireless power signal... | The accused chargers contain a transmission coil to generate the magnetic field for wireless power transfer. | ¶31, ¶51 | col. 8:39-42 |
| at least one controller comprising... executable code... to... define the configurable frequency... define the configurable voltage level... define the configuration state... | The accused chargers allegedly use a microcontroller to dynamically manage the frequency, voltage, and capacitor settings in accordance with the Qi2 standard's requirements for power control. | ¶31, ¶51 | col. 20:1-34 |
- Identified Points of Contention: The analysis may focus on whether the specific control logic and hardware architecture for dynamic tuning in the accused products align with the limitations of claim 1. A potential question is whether the term "bank of two or more capacitors" can be construed to read on the specific capacitor arrangement implemented in the accused chargers.
’970 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a power-supply interface that is operable to receive... a supply voltage signal... | The accused chargers are alleged to connect to external power adapters via a physical interface (e.g., USB-C) to receive power. | ¶31, ¶51 | col. 28:1-4 |
| a power conditioning system that is operable to... produce an alternating current ("AC") signal... | The accused chargers are alleged to contain inverter circuitry to generate the AC signal for driving the transmission antenna. | ¶31, ¶51 | col. 23:53-56 |
| at least one controller... to... send, to the external power supply, a request that the external power supply change the configurable voltage level... | Qi2 chargers are alleged to communicate with external power supplies (e.g., via USB-PD protocol) to negotiate and request specific voltage levels. | ¶31, ¶51 | col. 28:5-10 |
| detect that the external power supply has changed the configurable voltage level... | The controller in the accused chargers allegedly monitors or receives confirmation that the external power supply has switched to the requested voltage. | ¶31, ¶51 | col. 28:11-14 |
| after detecting that the external power supply has changed... cause the configurable frequency of the drive signal to be changed... | After the voltage change is confirmed, the controller in the accused chargers allegedly adjusts its own operating frequency to achieve the desired power output level. | ¶31, ¶51 | col. 28:15-20 |
- Identified Points of Contention: A key question will likely be evidentiary: does the control logic of the accused products execute the claimed sequence of operations? Specifically, the analysis will question whether the device performs a distinct "detect" step after requesting a voltage change and before it causes the frequency to change, as the claim language requires.
V. Key Claim Terms for Construction
’084 Patent
- The Term: "bank of two or more capacitors"
- Context and Importance: This term defines a key hardware component of the claimed invention. The infringement analysis will depend on whether the capacitor arrangement within the accused products falls within the scope of this term.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification describes the component as a "dynamic tuning capacitor circuit" having a "plurality of selectable capacitors," which could support an interpretation covering any arrangement of multiple switchable capacitors used for tuning ('084 Patent, col. 3:41-44).
- Evidence for a Narrower Interpretation: The embodiment depicted in Figure 8 shows a specific arrangement of four capacitors (CTXA, CTXB, CTXC, CTXN) that appear to be switched in parallel ('084 Patent, Fig. 8). A party could argue the term should be limited to such parallel configurations or the specific structures disclosed.
’970 Patent
- The Term: "detect that the external power supply has changed"
- Context and Importance: This term describes a critical step in the claimed method, creating a required temporal and causal link between the power supply's action and the transmitter's subsequent action. Practitioners may focus on this term because infringement depends on proving this specific detection step occurs, as opposed to the transmitter simply assuming the change happened after a time delay.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: Claim 1 does not specify the mechanism of detection. This could support a broad reading that covers various methods, such as direct voltage measurement or receiving a digital confirmation message through a communication protocol like USB-PD ('970 Patent, col. 28:11-14).
- Evidence for a Narrower Interpretation: A party might argue that "detect" implies an active measurement by the transmitter itself, rather than passive receipt of a confirmation message. If the accused device relies solely on a protocol handshake without independent verification, it raises the question of whether this meets the "detect" limitation.
VI. Other Allegations
- Direct Infringement: The complaint alleges direct infringement under 35 U.S.C. § 271(a), stating that Defendant "has been, and now is, directly infringing claims of the Patents-in-Suit... by making, using, offering for sale, selling, and/or importing" the accused products (Compl. ¶41).
- Willful Infringement: The complaint alleges that Defendant’s infringement is willful and deliberate (Compl. ¶¶57-58). The basis for this allegation is Defendant’s alleged pre-suit knowledge of the patents, stemming from at least four emails and two letters sent by Plaintiff starting on April 11, 2024, which included license offers and claim charts, and Defendant's subsequent and continuing sale of the accused products despite these notices (Compl. ¶¶43, 44, 49, 58).
VII. Analyst’s Conclusion: Key Questions for the Case
- Claim Scope vs. Industry Standard: A central issue will be whether compliance with the Qi2 standard, as alleged in the complaint, necessarily constitutes infringement of the asserted patent claims. The case will likely require a detailed technical comparison to determine if the specific methods and structures required by the Qi2 standard are coextensive with the patent claims, or if non-infringing implementations of the standard are possible.
- Proof of Operation: For the method claims in patents like the ’970 Patent, a key evidentiary question will be one of operational sequence: can Plaintiff demonstrate that the accused products’ firmware executes the precise sequence of requesting a voltage change, then detecting that change, and only then changing the operating frequency? This will likely depend on technical evidence obtained through discovery and product analysis.
- Definitional Boundaries: The dispute may turn on a question of definitional scope: can terms like "bank of two or more capacitors" ('084 Patent) be construed broadly to cover any switched capacitor array used for tuning, or will the court limit the term to the specific parallel arrangements shown in the patent's figures? The outcome of such claim construction questions will be critical in determining the reach of the patents.