DCT
2:25-cv-00779
Nucurrent Inc v. Hong Kong Ugreen Ltd
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: NuCurrent, Inc. (Delaware)
- Defendant: Hong Kong Ugreen Limited (Hong Kong)
- Plaintiff’s Counsel: Global IP Law Group, LLC
- Case Identification: 2:25-cv-00779, E.D. Tex., 08/11/2025
- Venue Allegations: Venue is asserted under 28 U.S.C. § 1391(c)(3), which permits a defendant not resident in the United States to be sued in any judicial district.
- Core Dispute: Plaintiff alleges that Defendant’s Qi2-compliant wireless chargers infringe two U.S. patents related to dynamic power control and frequency adjustment in wireless power systems.
- Technical Context: The technology at issue involves methods for optimizing wireless power transfer efficiency and control, particularly for consumer electronics that must operate reliably under varying conditions and with external power sources.
- Key Procedural History: Plaintiff alleges it provided Defendant with notice of the patents-in-suit and offers to license on RAND terms beginning April 11, 2024, including sending a 541-page letter with claim charts. The complaint alleges Defendant did not respond to these communications, which forms the basis for the willfulness allegations.
Case Timeline
| Date | Event |
|---|---|
| 2020-01-03 | U.S. Patent No. 12,184,084 Priority Date |
| 2020-04-30 | U.S. Patent No. 12,272,970 Priority Date |
| 2024-04-11 | Plaintiff first provides notice of infringement to Defendant |
| 2024-05-03 | Plaintiff's infringement notice letter delivered to Defendant |
| 2024-12-31 | U.S. Patent No. 12,184,084 Issues |
| 2025-04-08 | U.S. Patent No. 12,272,970 Issues |
| 2025-08-11 | 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 patent addresses the problem of "disturbances" in wireless power transfer, such as varying coil distances, temperature changes, and altered impedances, which can negatively affect the performance and efficiency of a wireless charging system ('084 Patent, col. 1:60 - col. 2:4).
- The Patented Solution: The invention is a system that uses a "dynamic tuning controller" to actively manage these disturbances. The controller receives data from various sensors (e.g., temperature, current, voltage) and, in response, adjusts "forward gain elements" of the system—such as the operating frequency, the supply voltage from a voltage regulator, or the capacitance of a tuning circuit—to maintain optimal power transfer ('084 Patent, Abstract; col. 2:12-39). Figure 8 illustrates this closed-loop system, where a central controller (350) receives sensor inputs and sends control signals to various tunable components of the transmitter and receiver.
- Technical Importance: This approach allows a wireless charger to maintain high efficiency and operate safely across a wide range of real-world conditions, which is critical for consumer products that may be misaligned or used with accessories like phone cases ('084 Patent, col. 2:5-11).
Key Claims at a Glance
- The complaint asserts independent claim 1 and dependent claims 3-13, 21, and 22 (Compl. ¶34).
- Independent Claim 1 requires:
- A voltage regulator that produces a supply voltage based on a first control signal.
- An inverter that produces a first AC signal with a configurable frequency and power level.
- A capacitor circuit with a "bank of two or more capacitors" that is configured by a second control signal to tune the first AC signal, producing a second AC signal.
- A transmission antenna to produce a wireless power signal from the second AC signal.
- A controller with code to define the configurable frequency, voltage level, and capacitor configuration state, and to provide the corresponding control signals to the voltage regulator and capacitor circuit.
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: The patent identifies the need for more granular power control in wireless transmitters, especially for extended-range applications that charge through surfaces or cases. It notes that achieving this control with conventional internal voltage regulation hardware can be complex and expensive, and seeks a way to work more effectively with common external power supplies ('970 Patent, col. 2:1-24; col. 3:15-33).
- The Patented Solution: The invention describes a method where the transmitter controls its power output by coordinating with an external power supply. The transmitter's controller sends a request for the external supply to change its output voltage to a new base level. After detecting that this voltage change has occurred, the controller then makes fine-tuned adjustments to the power level by altering the frequency of the drive signal sent to its internal inverter. This offloads the coarse voltage regulation to the external supply, simplifying the transmitter's internal design ('970 Patent, Abstract; col. 4:1-14).
- Technical Importance: This method enables the design of less expensive and more versatile extended-range wireless chargers that can leverage common "off-the-shelf" power sources like USB-PD adapters, using frequency shifting as a tool for fine power control ('970 Patent, col. 3:34-40).
Key Claims at a Glance
- The complaint asserts independent claims 1 and 19, and various dependent claims (Compl. ¶34).
- Independent Claim 1 requires:
- A power-supply interface to receive a supply voltage from an external power supply.
- A power conditioning system (including an inverter) to produce an AC signal.
- A capacitor circuit and a transmission antenna.
- A controller with code that causes it to:
- Send a request to the external power supply to change the voltage from a first to a second level.
- Detect that the external supply has made the requested voltage change.
- After detecting the change, cause the frequency of the drive signal to be changed.
III. The Accused Instrumentality
Product Identification
- The complaint identifies a range of "Accused Ugreen Qi2 Wireless Chargers," sold through various channels including Ugreen's website, Amazon, and Best Buy (Compl. ¶¶ 14-19, 21). A screenshot from the Wireless Power Consortium ("WPC") database lists 29 Ugreen products as "Qi2 compliant" (Compl. ¶20, p. 5-6).
Functionality and Market Context
- The accused products are alleged to be wireless charging accessories for mobile devices that operate in compliance with the Qi2 Specification of the WPC (Compl. ¶21). This standard enables magnetic attachment and alignment for devices like iPhones and delivers power up to 15W (Compl. ¶24). The complaint provides a photograph of one such product, the "2-in-1 Magnetic Wireless Charger" (Model #: W710), and its packaging, which explicitly markets the device as "Qi2-certified" and capable of delivering 15W of power (Compl. ¶¶ 23-24, p. 7). The allegations suggest these products are commercially significant, being sold through major U.S. retailers (Compl. ¶¶ 15, 18, 19).
IV. Analysis of Infringement Allegations
The complaint alleges that the Accused Ugreen Qi2 Wireless Chargers meet each limitation of the asserted claims but does not provide a detailed element-by-element breakdown or claim chart exhibit (Compl. ¶35). The infringement theory appears to be that compliance with the Qi2 standard inherently requires the functionality described in the patents.
'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 in accordance with the first control signal | The accused Qi2 chargers are alleged to contain power regulation circuitry that adjusts internal voltage levels based on control signals to manage power delivery. | ¶¶ 22, 35 | col. 20:23-44 |
| an inverter that is operable to... produce a first AC signal having the configurable frequency and a configurable power level | The accused Qi2 chargers allegedly contain an inverter to create the AC field for wireless charging, with its frequency and power being configurable as required for Qi2 operation. | ¶¶ 22, 35 | col. 14:1-11 |
| a capacitor circuit that comprises a bank of two or more capacitors and is operable to... configure the bank... and... tune the first AC signal | The accused Qi2 chargers are alleged to use tunable capacitor circuits to match impedance and optimize power transfer under different conditions, a necessary function for reliable 15W charging. | ¶¶ 22, 35 | col. 21:32-49 |
| a transmission antenna that is operable to... produce a wireless power signal | The accused chargers, such as the one depicted in a photograph, contain a transmission coil to generate the wireless power field. | ¶23 | col. 8:38-44 |
| at least one controller comprising... executable code... that... causes the at least one controller to: define the configurable frequency... define the configurable voltage level... define the configuration state of the bank of two or more capacitors... | The accused Qi2 chargers allegedly include a controller that manages the charging process by defining and sending control signals to the power circuitry to comply with the Qi2 standard's dynamic power requirements. | ¶¶ 21-22, 35 | col. 38:27-44 |
- Identified Points of Contention:
- Technical Question: What evidence demonstrates that the accused chargers use a "bank of two or more capacitors" that is dynamically "configured" by a control signal, as recited in the claim, rather than using a fixed or differently tuned capacitor circuit? The complaint's general allegations of Qi2 compliance may not be sufficient to prove this specific hardware implementation.
- Scope Question: Does the term "dynamically tuning," in the context of the patent, cover the standard power negotiation protocol of Qi2, or does it require a more specific method of disturbance detection and correction as described in the '084 patent's specification?
'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, from an external power supply, a supply voltage signal | The accused Qi2 chargers are alleged to operate with external power supplies (e.g., USB-C adapters) and contain an interface to receive power from them. | ¶¶ 15, 24 | col. 28:1-3 |
| at least one controller... causes the at least one controller to: send, to the external power supply, a request that the external power supply change the configurable voltage level | The accused Qi2 chargers allegedly communicate with external power supplies, such as under the USB Power Delivery protocol, to negotiate and request specific voltage levels for operation. | ¶¶ 21-22, 35 | col. 28:39-44 |
| ... detect that the external power supply has changed the configurable voltage level of the supply voltage signal | The controller in the accused chargers allegedly monitors the incoming voltage to confirm that the external power supply has responded to the request and is providing the new voltage level. | ¶¶ 21-22, 35 | col. 28:45-48 |
| ... after detecting that the external power supply has changed... cause the configurable frequency of the drive signal to be changed | The accused chargers are alleged to adjust their internal operating frequency to fine-tune power delivery after confirming the new base voltage from the external supply, as part of the Qi2 power control scheme. | ¶¶ 21-22, 35 | col. 28:49-56 |
- Identified Points of Contention:
- Technical Question: The core of the claim is the specific sequence: (1) request voltage change, (2) detect voltage change, (3) then change frequency. What evidence will show that the accused chargers perform precisely this sequence, as opposed to changing frequency and voltage simultaneously or based on other control logic?
- Scope Question: What level of sensing constitutes "detect[ing] that the external power supply has changed"? Does simply operating under the new voltage suffice, or does the claim require a discrete verification step by the controller before the frequency is altered?
V. Key Claim Terms for Construction
'084 Patent, Claim 1: "bank of two or more capacitors"
- Context and Importance: The infringement analysis for the '084 patent may depend on whether the accused products contain this specific hardware structure. The definition will determine if any system with switchable capacitance infringes, or only those with a particular arrangement.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The claim language itself does not specify the physical arrangement of the capacitors, only that a "bank" exists and is "operable to... configure" and "tune." This could be argued to cover any circuit with multiple selectable capacitors used for tuning.
- Evidence for a Narrower Interpretation: The specification describes a specific embodiment where the "number of possible switchable states of capacitance will be n² switchable states" for a bank of 'n' capacitors, implying a particular matrix or parallel/series switching configuration ('084 Patent, col. 21:45-49). A defendant might argue this embodiment limits the term to such complex arrangements, not just any two capacitors.
'970 Patent, Claim 1: "after detecting that the external power supply has changed... cause the configurable frequency... to be changed"
- Context and Importance: This temporal and causal language is central to the infringement allegation for the '970 patent. The case may turn on whether the accused products perform this exact sequence of operations. Practitioners may focus on this term because it establishes a required order of operations that may or may not be present in the accused devices.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: A plaintiff might argue that "detecting" is an inherent part of the system's operation; if the circuit's behavior changes due to the new voltage, the controller has functionally "detected" it, and any subsequent frequency change meets the limitation. The patent does not explicitly define the mechanism of detection.
- Evidence for a Narrower Interpretation: The claim structure "after detecting... cause... to be changed" suggests a sequential, two-step process. A defendant could argue this requires the controller to run a specific routine to confirm the voltage change is complete and stable before initiating a separate routine to change the frequency, a more stringent requirement than simply having the two events occur in succession.
VI. Other Allegations
- Indirect Infringement: The complaint makes a general allegation that Defendant acts "directly and/or through subsidiaries and agents (including distributors, retailers, and others)" to make, use, and sell the accused products (Compl. ¶7). However, it does not plead specific facts to support a claim for induced infringement, such as instructing users via manuals to perform an infringing act.
- Willful Infringement: The complaint explicitly pleads willful infringement based on alleged pre-suit knowledge (Compl. ¶¶ 40-41). The basis is a series of alleged communications starting on April 11, 2024, including emails and a 541-page letter with notice and claim charts, to which Defendant allegedly "refused to respond, acknowledge, or engage in any discussion" (Compl. ¶¶ 27-30, 32).
VII. Analyst’s Conclusion: Key Questions for the Case
A central evidentiary question will be one of technical implementation: Do the accused Ugreen Qi2 chargers, by virtue of being "Qi2 compliant," necessarily practice the specific hardware and software steps recited in the claims? For instance, do they utilize a dynamically configured "bank of two or more capacitors" ('084 patent) and execute the precise "request-detect-change frequency" sequence ('970 patent), or do they achieve Qi2 compliance through different means?
The case will also likely turn on a question of claim scope: Can the patents' claims, which describe specific control-loop architectures, be interpreted broadly enough to read on the standardized power management protocols of the Qi2 standard? The outcome may depend on whether the court views the patented methods as a narrow solution or as foundational to the type of dynamic power control required by modern wireless charging.