Shenzhen Zhiying Technology Co Ltd v. Hong Kong Xingtai Intl Trade Co Ltd

I. Executive Summary and Procedural Information

• Case Name: Shenzhen Zhiying Technology Co., Ltd. v. Hong Kong Xingtai International Trade Co Limited
• Parties & Counsel:
  • Plaintiff: Shenzhen Zhiying 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-02263, W.D. Wash., 11/13/2025
• Venue Allegations: Venue is based on Defendant’s patent enforcement activities directed into the district, specifically by initiating an Amazon "Patent Evaluation Express" proceeding and sending communications to Amazon personnel located in Seattle, Washington.
• 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 dispute concerns solar-powered decorative string lights, a consumer product category that utilizes small solar panels and rechargeable batteries to power lights automatically at night.
• Key Procedural History: The complaint states that this action was precipitated by Defendant's enforcement of its patent through Amazon's "Patent Evaluation Express" (APEX) program, which threatened the removal of Plaintiff's product listings from the e-commerce platform. The case is a declaratory judgment action, where the accused infringer (the Plaintiff) has preemptively sued the patent holder (the Defendant).

Case Timeline

Date	Event
2008-07-14	’545 Patent Priority Date
2010-10-26	’545 Patent Issue Date
2025-10-30	Defendant allegedly reports infringement to Amazon
2025-11-13	Complaint Filing Date

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

U.S. Patent No. 7,819,545 - Outdoor Solar Decorative Lights

• Patent Identification: U.S. Patent No. 7,819,545, titled “Outdoor Solar Decorative Lights,” issued October 26, 2010 (the “’545 Patent”).

The Invention Explained

• Problem Addressed: The patent’s background section describes problems associated with conventional outdoor decorative lights, which require external power from residential electrical outlets. This presents "the very real danger of electrical shorts and shocks" and creates trip hazards from extension cords exposed to outdoor conditions. (’545 Patent, col. 1:33-49).
• The Patented Solution: The invention is a self-contained, solar-powered decorative lighting system. It comprises a string of lights electrically connected to a solar collector that contains solar panels and a rechargeable battery. (’545 Patent, Abstract). A key feature is an automatic switch that regulates power from the battery, turning the lights on at dusk and off at dawn, thereby eliminating the need for external power cords and manual operation. (’545 Patent, col. 2:63-67; Fig. 7).
• Technical Importance: The described technology provides a safer and more convenient alternative to traditional decorative lights by obviating the need for "long and cumbersome electrical extension cords," reducing electricity costs, and automating the on/off cycle. (’545 Patent, col. 2:50-58).

Key Claims at a Glance

• The complaint asserts that claims 1-3 of the ’545 Patent are at issue (Compl. ¶38). Independent claim 1 is the focus of the non-infringement allegations (Compl. ¶21).
• Independent Claim 1 requires:
  • A flexible, elongated light string with evenly spaced sockets and light bulbs.
  • A solar collector with a housing and at least one solar panel for collecting radiant energy.
  • A rechargeable battery contained within the housing.
  • A "regulator switch" that is electrically interconnected to the battery and light string.
  • The switch automatically switches the lights on and off, specifically being "disposed to the open state from sunrise to sunset" and "automatically going to the closed state upon sunset."
• The complaint notes that dependent claims 2 and 3 incorporate the limitations of claim 1 (Compl. ¶26).

III. The Accused Instrumentality

Product Identification

• The accused products are Plaintiff's "outdoor solar decorative light products," identified in the complaint by a list of Amazon Standard Identification Numbers (ASINs) (the "Accused Product") (Compl. ¶¶1, 11).

Functionality and Market Context

• The complaint describes the Accused Product as having a "control architecture (including photosensor/IC logic and user controls)" that operates based on "instantaneous ambient-light conditions" (Compl. ¶23). This functionality allegedly allows the lights to illuminate during daytime hours if the solar panel is covered or in other low-light scenarios (Compl. ¶23).
• Plaintiff alleges that the Amazon marketplace is its "primary sales channel in the United States" and that Defendant's enforcement actions threaten to remove its listings and cut off access to its customers (Compl. ¶14).
  No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint seeks a declaratory judgment of non-infringement. The analysis below summarizes the Plaintiff’s arguments for why its product does not meet at least one key limitation of the asserted patent claim.

• ’545 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Non-Infringing Functionality	Complaint Citation	Patent Citation
a regulator switch ... whereby the switch is disposed to the open state from sunrise to sunset ... and the switch automatically going to the closed state upon sunset thereby closing the circuit and causing the light bulbs to light.	The Accused Product’s control architecture operates on instantaneous ambient-light conditions and permits illumination during daylight low-light scenarios, rather than maintaining an open circuit continuously "from sunrise to sunset" and only closing "upon sunset."	¶23	col. 6:20-27

• Identified Points of Contention:
  • Scope Questions: A primary dispute appears to concern the temporal and operational requirements of the "regulator switch." The complaint raises the question of whether the claim language "disposed to the open state from sunrise to sunset" requires a continuous, uninterruptible "off" state during all daylight hours, or if it can be interpreted to read on a system that is simply designed to be off during the day but may activate in response to transient low-light events (Compl. ¶¶23, 24).
  • Technical Questions: The infringement analysis may turn on the structural and functional differences between the patent's described "regulator switch" and the Accused Product's "control architecture (including photosensor/IC logic)" (Compl. ¶23). The complaint suggests a distinction between a single, dedicated switch with a defined temporal state and a more dynamic, logic-based control system, raising the question of whether these are technically or legally equivalent structures.

V. Key Claim Terms for Construction

• The Term: "a regulator switch ... disposed to the open state from sunrise to sunset"
• Context and Importance: The construction of this term appears central to the non-infringement argument. Plaintiff contends that its products, which react to instantaneous light levels, do not meet this limitation because they do not maintain a continuous "open state" throughout the entire period from sunrise to sunset (Compl. ¶23). Practitioners may focus on this term because its interpretation—whether it implies a continuous state or a general mode of operation—could be dispositive of infringement.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: A patentee might argue the phrase describes the system's intended function—to be off during the day and on at night—and should not be read so rigidly as to exclude activation during anomalous daytime darkness. The patent's stated objective is to "come on automatically at dusk and turn off automatically at dawn," which could be argued as a general goal rather than a strict command for every second of the day (’545 Patent, col. 2:65-67).
  • Evidence for a Narrower Interpretation: The Plaintiff will likely emphasize the specific claim language "disposed to the open state from sunrise to sunset" (’545 Patent, col. 6:23-24). This position may be supported by the specification, which states "the switch 66 is maintained in an open state during periods of daylight (detection of light between sunrise and sunset adjusted seasonally)" (’545 Patent, col. 5:17-20), language that suggests a continuous, maintained condition for a defined period.

VI. Other Allegations

• Indirect Infringement: The complaint affirmatively pleads non-infringement for both induced and contributory infringement. It alleges that the Accused Product is "a staple article of commerce suitable for substantial non-infringing uses" and that Plaintiff has not encouraged or instructed customers to practice every element of the asserted claims (Compl. ¶¶25-26).

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

This declaratory judgment action will likely focus on two central issues for the court to resolve:

• 1. Claim Construction: A core issue will be one of definitional scope: does the claim term "disposed to the open state from sunrise to sunset" require a continuous and uninterrupted state of being "off" during daylight hours, or can it be construed to cover a system that responds to instantaneous ambient light levels, even if that results in the lights activating during the day under certain conditions?
• 2. Invalidity: A second critical question will be one of obviousness: do the prior art references cited in the complaint, which allegedly disclose various solar-powered lighting systems with automatic on/off controls, render the specific switching behavior and overall combination of Claim 1 of the ’545 Patent obvious to a person of ordinary skill in the art at the time of the invention?