DCT
2:25-cv-02261
Shenzhen Yilv Technology Co Ltd v. Hong Kong Xingtai Intl Trade Co Ltd
Key Events
Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Shenzhen Yilv Technology Co., Ltd. (China)
- Defendant: Hong Kong Xingtai International Trade Co Limited (Hong Kong)
- Plaintiff’s Counsel: Glacier Law LLP
- Case Identification: 2:25-cv-02261, W.D. Wash., 11/13/2025
- Venue Allegations: Plaintiff alleges venue is proper because Defendant directed patent enforcement activities, specifically through Amazon’s "Patent Evaluation Express" program, toward Amazon personnel located in the Western District of Washington, with the intended effect of delisting Plaintiff's products.
- Core Dispute: Plaintiff seeks a declaratory judgment that its outdoor solar decorative light products do not infringe Defendant’s patent related to solar-powered lighting systems, and/or that the patent is invalid.
- Technical Context: The technology concerns outdoor decorative light strings powered by a solar collector and a rechargeable battery, designed to operate automatically based on ambient light levels.
- Key Procedural History: The dispute arose from Defendant's accusation of infringement communicated to Plaintiff via the Amazon marketplace, threatening the removal of Plaintiff’s product listings unless Plaintiff engaged in Amazon's "Patent Evaluation Express" process.
Case Timeline
| Date | Event |
|---|---|
| 2008-07-14 | ’545 Patent Priority Date |
| 2010-10-26 | ’545 Patent Issue Date |
| 2025-10-30 | Defendant accuses Plaintiff of infringement via Amazon |
| 2025-11-13 | Complaint for Declaratory Judgment filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 7,819,545 - “Outdoor Solar Decorative Lights,” issued October 26, 2010
The Invention Explained
- Problem Addressed: Conventional decorative outdoor lights require being plugged into a residential electrical outlet, creating risks of electrical shorts from weather exposure, tripping hazards from extension cords, and ongoing electricity costs (’545 Patent, col. 1:35-49).
- The Patented Solution: The invention is a self-contained, solar-powered decorative lighting system. It comprises a flexible light string connected to a solar collector that houses solar panels and a rechargeable battery (’545 Patent, col. 2:24-35). The system includes a switch that automatically activates the lights at dusk and deactivates them at dawn, eliminating the need for external power, extension cords, and manual operation (’545 Patent, col. 2:64-67). Figure 7 provides a flowchart illustrating this automatic switching logic based on the detection of ambient light (’545 Patent, Fig. 7).
- Technical Importance: The invention aimed to provide a safer, more convenient, and cost-effective alternative to traditional electric-powered decorative lights by leveraging solar power and automated control (’545 Patent, col. 2:46-53).
Key Claims at a Glance
- Independent Claim 1:
- a flexible, elongated light string;
- an electrical wire extending through the string;
- a plurality of evenly spaced sockets mounted on the string;
- a plurality of light bulbs mounted to the sockets;
- a solar collector electrically connected to the light string, which includes a housing and at least one solar panel;
- a rechargeable battery contained within the housing and connected to the solar panel; and
- a regulator switch interconnected to the battery and light string for automatically switching the bulbs on and off, where the switch is disposed to the open state from sunrise to sunset and automatically goes to the closed state upon sunset.
- The complaint notes that dependent claims 2-3 incorporate the limitations of claim 1 (Compl. ¶26).
III. The Accused Instrumentality
Product Identification
- Plaintiff’s "outdoor solar decorative light products," also referred to as the "Accused Product" or "Decorative Lights" (Compl. ¶23).
Functionality and Market Context
- The complaint describes the Accused Product as having a control architecture, including a photosensor and IC logic, that operates based on "instantaneous ambient-light conditions" (Compl. ¶23). This functionality permits the lights to illuminate during daylight hours if conditions are dark enough, such as in low-light situations or when the solar panel is covered (Compl. ¶23).
- The Amazon marketplace is alleged to be the Plaintiff's primary sales channel in the United States, making the threatened removal of its product listings a significant commercial harm (Compl. ¶14).
- No probative visual evidence provided in complaint.
IV. Analysis of Infringement Allegations
The following summarizes the non-infringement positions asserted by the Plaintiff in its declaratory judgment complaint.
’545 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a flexible, elongated light string | The Accused Product is a string of outdoor solar decorative lights. | ¶23 | col. 6:3-4 |
| a solar collector electrically connected to the light string | The Accused Product includes a solar collector. | ¶23 | col. 6:11-13 |
| a rechargeable battery contained within the housing | The Accused Product includes a rechargeable battery. | ¶23 | col. 6:17-20 |
| a regulator switch...for automatically switching the light bulbs on and off whereby the switch is disposed to the open state from sunrise to sunset...and automatically going to the closed state upon sunset... | The Accused Product's control architecture (photosensor/IC logic) automatically switches the lights based on ambient light. | ¶23 | col. 6:21-28 |
Identified Points of Contention
- Scope Questions: The central dispute appears to be whether the Accused Product’s control system, which allegedly responds to "instantaneous ambient-light conditions," meets the claim limitation of a "regulator switch" that is specifically "disposed to the open state from sunrise to sunset" (Compl. ¶23). Plaintiff argues that its product's ability to turn on during the day if the panel is covered is inconsistent with the claimed continuous "open state from sunrise to sunset" (Compl. ¶¶ 23-24).
- Technical Questions: What evidence will be presented to establish the precise operational logic of the Accused Product’s control architecture? The case may turn on whether the accused circuitry maintains a state functionally equivalent to being continuously "open" during daylight hours, or if its instantaneous response creates a material difference in operation that falls outside the claim scope (Compl. ¶23).
V. Key Claim Terms for Construction
- The Term: "a regulator switch... disposed to the open state from sunrise to sunset... and automatically going to the closed state upon sunset"
- Context and Importance: The entirety of Plaintiff's non-infringement argument rests on this term. Plaintiff contends its product does not meet this limitation because its lights can activate during the daytime in low-light conditions, which it argues is contrary to a switch that remains in an "open state from sunrise to sunset" (Compl. ¶23). The construction of this temporal and functional language will be dispositive for infringement.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The Defendant may argue that the phrase "from sunrise to sunset" is a general description of the switch's intended daily cycle, not a rigid command that prohibits any activation during daylight. The specification describes the switch's function more broadly as regulating current "through the detection or non-detection of ambient light" (’545 Patent, col. 5:16-18), which could be argued to encompass the accused functionality.
- Evidence for a Narrower Interpretation: The Plaintiff will likely emphasize the explicit language of the claim itself, arguing that "from sunrise to sunset" defines a continuous and unbroken period during which the circuit must remain open, preventing the lights from lighting. The specification's description of the switch maintaining an "open state during periods of daylight" and a "closed state by the non-detection of light (immediately upon sunset...)" may be used to support this stricter temporal requirement (’545 Patent, col. 5:18-22).
VI. Other Allegations
- Indirect Infringement: The complaint asserts that Plaintiff has not induced or contributed to infringement, alleging its product materials describe only non-infringing uses and that the product is a staple article of commerce suitable for substantial non-infringing uses (Compl. ¶25).
- Willful Infringement: The complaint does not contain allegations of willfulness against the Defendant. This section is not applicable.
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of claim scope and temporal definition: Does the claim limitation "disposed to the open state from sunrise to sunset" require the switch to maintain an unbroken open circuit throughout all daylight hours, or can it be construed more broadly to describe a general light-sensing function that primarily operates on a day/night cycle but may react to anomalous darkness during the day?
- A second key question will be one of invalidity based on obviousness: Plaintiff has identified numerous prior art references allegedly disclosing the key elements of the claimed invention, including solar panels, rechargeable batteries, light strings, and automatic light-sensing controllers (Compl. ¶¶ 34-38). The central question for the court will be whether combining these known elements to create the claimed system would have been obvious to a person of ordinary skill in the art at the time of the invention.