DCT
1:25-cv-22599
Shenzhen Hehong Technology Co Ltd v. Luo
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Shenzhen Hehong Technology Co., Ltd. and Shenzhen Dushu Culture Advertising Co., Ltd. (People's Republic of China)
- Defendant: Xiaohua Luo (People's Republic of China)
- Plaintiff’s Counsel: Law Firm of Rubio & Associates, P.A.
- Case Identification: 1:25-cv-22599, S.D. Fla., 06/18/2025
- Venue Allegations: Plaintiffs allege venue is proper because the Defendant’s patent enforcement actions, initiated through Amazon's APEX procedure, target product listings accessible for sale within the Southern District of Florida, and a substantial part of the events giving rise to the action will occur in the district.
- Core Dispute: Plaintiffs seek a declaratory judgment that their decorative string-light controller products do not infringe Defendant’s patent related to edge-triggered computing circuits, and further seek a declaration that the patent is invalid.
- Technical Context: The technology at issue concerns electronic circuits that use a single power supply line to transmit both electrical power and control signals, a method significant for simplifying wiring and reducing costs in consumer electronics like LED lighting systems.
- Key Procedural History: The dispute arose after the Defendant, Xiaohua Luo, initiated an enforcement action through Amazon's Patent Evaluation Express (APEX) procedure, alleging that Plaintiffs' products infringe the patent-in-suit. This action prompted Plaintiffs to file for a declaratory judgment of non-infringement and invalidity.
Case Timeline
| Date | Event |
|---|---|
| 2014-10-10 | U.S. Patent No. 9,723,679 Priority Date |
| 2017-08-01 | U.S. Patent No. 9,723,679 Issues |
| 2025-03-31 | Defendant executes APEX Agreements against Plaintiffs |
| 2025-06-18 | Complaint for Declaratory Judgment Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 9,723,679 - "Computing Apparatus and LED Driver"
- Patent Identification: U.S. Patent No. 9,723,679, "Computing Apparatus and LED Driver," issued August 1, 2017 (’679 Patent).
The Invention Explained
- Problem Addressed: The patent addresses the limitations of conventional LED control systems, which typically require one or more dedicated signal lines in addition to the power and ground lines to control lighting effects. This complexity is unsuitable for applications where only a power supply line and a ground line are available. (’679 Patent, col. 1:47-53).
- The Patented Solution: The invention discloses a computing apparatus that can be controlled using only the power supply line. It achieves this with three core components: an "edge-triggered computing device" that performs computations based on rising or falling voltage edges on the power line, a "charging device" that draws power from the same line to run the circuit, and an "initialization device" that resets the computing device based on the stored voltage. (’679 Patent, Abstract; Fig. 1). This architecture enables both power and data to be transmitted over the same two wires.
- Technical Importance: This design facilitates the on-chip implementation of LED driving circuits and simplifies the overall system architecture, which is valuable for reducing cost and complexity in mass-market consumer electronics. (’679 Patent, Abstract).
Key Claims at a Glance
- The complaint asserts non-infringement and invalidity of independent claim 1 (Compl. ¶¶10, 18, 25).
- Essential elements of Claim 1 include:
- A computing apparatus configured to be triggered by input signal edges from a power supply line, comprising an edge-triggered computing device, a charging device, and an initialization device;
- The edge-triggered computing device is configured to be triggered to perform computing by the input signal edges from the power supply line;
- The charging device is configured to supply power to the edge-triggered computing device based on the input signals from the power supply line;
- The charging device is charged when the input signal from the power supply line is at a high voltage, and is discharged when it is at a low voltage;
- The initialization device is configured to initialize the edge-triggered computing device based on the voltage of the power supplied by the charging device.
- The complaint does not explicitly reserve the right to address dependent claims but focuses its analysis entirely on Claim 1.
III. The Accused Instrumentality
Product Identification
Plaintiffs’ decorative string-light controller products, identified as "RGB music-sync changing lights" and sold on Amazon under ASINs B08BJ5Y4PN, B0DFCJR3YN, and B0D3QNSK9N (the "Accused Products") (Compl. ¶17).
Functionality and Market Context
The complaint alleges the Accused Products operate on a "fundamentally different architecture" from the patented invention (Compl. ¶13). Instead of detecting signal edges, the products are alleged to perform "level-duration decoding" by comparing the line signal to a stable reference voltage and measuring the duration of high and low voltage states to decode pulse-width-modulated signals (Compl. ¶¶13, 20). The power-on-reset function is allegedly implemented with a "simple RC network (resistor and capacitor)," and the charging device allegedly uses actively regulated PMOS-controlled circuits (Compl. ¶¶13, 21).
IV. Analysis of Infringement Allegations
The complaint seeks a declaratory judgment of non-infringement. The following table summarizes the Plaintiffs’ arguments for why their products do not meet the limitations of Claim 1.
No probative visual evidence provided in complaint.
’679 Patent Non-Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Non-Infringing Functionality of Accused Products | Complaint Citation | Patent Citation |
|---|---|---|---|
| an edge-triggered computing device... configured to be triggered to perform computing by the input signal edges from the power supply line | The products allegedly do not trigger on signal edges. Instead, signal decoding is performed by a clock generator and logic modules that decode pulse-width-modulated signals by measuring the duration of high/low voltage levels. | ¶¶13, 20 | col. 2:40-43 |
| a charging device... is charged when the input signal from the power supply line is at a high voltage, and is discharged when... at a low voltage | The charging device allegedly includes actively regulated PMOS-controlled circuits and MOS capacitors, which differs from the passive diode-capacitor configuration described in the patent and allows for logic-controlled power gating. | ¶21 | col. 6:32-40 |
| an initialization device... configured to initialize the edge-triggered computing device based on the voltage of the power supplied by the charging device | The products allegedly use a logic-driven reset architecture with a "simple RC network" employing Schmitt triggers and oscillator timing. This is alleged to be fundamentally different from the patented passive, voltage-initialized device. | ¶¶13, 22 | col. 7:24-30 |
Identified Points of Contention
- Scope Questions: A primary dispute may center on the meaning of "triggered by input signal edges." The case will question whether a system that measures the duration of a voltage level (pulse-width decoding) to interpret a signal can be considered to be "triggered by" the rising and falling edges that define that level's duration.
- Technical Questions: The analysis will raise questions about structural and functional differences between the accused components and the claimed elements. What evidence exists to show that the Accused Products' "logic-driven reset architecture" (Compl. ¶22) operates differently than the claimed "initialization device"? Similarly, does the "actively regulated" PMOS charging circuit (Compl. ¶21) in the accused products function in a substantially different way than the claimed "charging device"?
V. Key Claim Terms for Construction
The Term: "edge-triggered computing device"
- Context and Importance: This term is central to the dispute. Plaintiffs contend their products perform "level-duration decoding" and are not "edge-triggered" (Compl. ¶¶13, 20). The construction of this term may be dispositive of infringement.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification states the device performs operations like "counting, arithmetic, logic or bit shift operations" and that the "transition either from low to high or from high to low of the input signal... is the input signal edge" (’679 Patent, col. 2:29-35). This functional language could support a construction that covers any computation initiated by a change in signal voltage.
- Evidence for a Narrower Interpretation: The patent’s primary embodiments describe the device as an "edge counting device" comprising a "plurality of D flip-flops connected in series" (’679 Patent, col. 2:45-52; Fig. 2). A party could argue the term should be limited to this specific counter-based architecture built with flip-flops, which Plaintiffs allege their products do not use (Compl. ¶19).
The Term: "initialization device"
- Context and Importance: Plaintiffs explicitly argue their products use a "simple RC network" and "logic-driven reset architecture," which they contrast with the claimed device (Compl. ¶¶13, 22). The scope of this term is a key element of the non-infringement argument.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: Claim 1 defines this element functionally: it "is configured to initialize the edge-triggered computing device based on the voltage of the power supplied by the charging device" (’679 Patent, col. 14:18-21). This could be interpreted to cover any circuit that performs this reset function based on the power state.
- Evidence for a Narrower Interpretation: The specification discloses a detailed embodiment of the initialization device comprising four specific MOSFETs and two inverters (’679 Patent, Fig. 4; col. 7:24-49). This specific circuit could be used to argue for a narrower construction that excludes the simple resistor-capacitor network Plaintiffs allege they use (Compl. ¶15).
VI. Other Allegations
The complaint is a declaratory judgment action and as such does not make affirmative allegations of infringement against the Defendant.
- Indirect Infringement: The complaint does not provide sufficient detail for analysis of potential indirect infringement theories, as it is focused on securing a declaration of non-infringement for Plaintiffs' own acts.
- Willful Infringement: The complaint does not provide sufficient detail for analysis of willfulness.
VII. Analyst’s Conclusion: Key Questions for the Case
The resolution of this declaratory judgment action may turn on the following central questions:
- A core issue will be one of definitional scope: Will the term "edge-triggered computing device" be construed broadly enough to encompass the "level-duration decoding" and "pulse width decoding" functionalities that Plaintiffs allege their products perform? This claim construction dispute appears to be the central point of contention.
- A key evidentiary question will be one of structural and functional non-equivalence: Can Plaintiffs demonstrate that their accused circuits—specifically the alleged "simple RC network" for initialization and the "actively regulated" PMOS circuit for charging—are substantially different, both structurally and functionally, from the apparatuses required by Claim 1, particularly when viewed in light of the detailed embodiments disclosed in the ’679 Patent?