DCT

2:26-cv-00133

Shenzhen Tongmingkai Technology Co Ltd v. Divevolk Zhuhai Intelligence Tech Co Ltd

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Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:26-cv-00133, W.D. Wash., 01/14/2026
  • Venue Allegations: Plaintiffs allege venue is proper in the Western District of Washington because Defendants purposefully availed themselves of the forum by using Amazon's patent enforcement procedures to delist products, and Amazon is a resident of the district where the alleged injury occurred.
  • Core Dispute: Plaintiffs seek a declaratory judgment that their waterproof smartphone cases do not infringe Defendant's U.S. Patent No. 10,761,628, alleging that Defendants have wrongfully used Amazon's internal patent dispute process to remove Plaintiffs' products from the online marketplace.
  • Technical Context: The technology concerns waterproof cases for electronic devices that enable touchscreen functionality in underwater environments, a key feature for consumers using smartphones for photography and other applications during aquatic activities.
  • Key Procedural History: The complaint states that this lawsuit was precipitated by Defendants' initiation of an Amazon Patent Evaluation Express (APEX) proceeding on December 25, 2025, which resulted in Amazon threatening to delist Plaintiffs' products based on Defendants' infringement allegations.

Case Timeline

Date Event
2016-06-30 '628 Patent Priority Date
2020-09-01 '628 Patent Issue Date
2025-12-25 Defendant initiated Amazon APEX proceeding
2026-01-14 Complaint Filing Date

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

U.S. Patent No. 10,761,628 - *Touch Control System of Electronic Product in Underwater Environment*

  • Patent Identification: U.S. Patent No. 10,761,628, “Touch Control System of Electronic Product in Underwater Environment,” issued September 1, 2020.

The Invention Explained

  • Problem Addressed: The patent’s background section identifies a technical challenge with using common capacitive touch screens underwater, as water's conductivity interferes with the screen's sensing mechanism, rendering it inoperable or unreliable (’628 Patent, col. 1:36-44). Conventional waterproof cases often fail to solve this, being either too rigid to allow touch input or too flimsy to resist water pressure (’628 Patent, col. 1:48-67).
  • The Patented Solution: The patent describes a sealing device featuring a “sealed chamber interlayer” filled with a non-conductive, “insulated fluid material” (’628 Patent, Abstract). This design isolates the phone’s screen from water. When a user applies external pressure, the fluid displaces, allowing the flexible interlayer to approach or contact the screen and register a touch input (’628 Patent, col. 7:29-36). A key embodiment also discloses an “air clearance” between the interlayer and the screen that connects to a “charging/discharging device” (e.g., an airbag) to equalize pressure at varying water depths (’628 Patent, col. 3:31-35; Claim 1).
  • Technical Importance: This approach aims to provide reliable, high-accuracy touchscreen operation underwater by combining the robust protection of a sealed case with a fluid-based, pressure-sensitive interface (’628 Patent, col. 2:19-24).

Key Claims at a Glance

  • The complaint’s non-infringement analysis focuses exclusively on independent claim 1 (Compl. ¶¶17, 35).
  • The essential elements of Claim 1 include:
    • A sealing device comprising a “sealed chamber interlayer” and a “sealed shell.”
    • The interlayer is filled with an “insulated fluid material.”
    • An “air clearance with uniform thickness” is arranged between the interlayer and the touch screen.
    • The air clearance “communicates with a charging/discharging device outside the sealing device.”

III. The Accused Instrumentality

Product Identification

  • The accused products are waterproof smartphone cases sold by the four plaintiffs through Amazon storefronts branded "Transy," "Ruihong-us," and "AlwaysDryGear," among others (Compl. ¶¶4, 7, 10, 13).

Functionality and Market Context

  • The products are marketed as waterproof cases compatible with various smartphones (Compl. p. 3). The complaint asserts that these products function differently from the patented invention, alleging that the device's touch screen is in "close contact with the sealed chamber interlayer," thereby lacking the claimed "air clearance" (Compl. ¶19). Further, the complaint states the products "do not require, include, or communicate with any charging/discharging device during operation" (Compl. ¶18). The Amazon marketplace is identified as the Plaintiffs' "primary sales channel into the United States" (Compl. ¶16).

IV. Analysis of Infringement Allegations

The complaint provides a side-by-side image comparing patent figures with a photograph of an accused product's cross-section, intended to illustrate the alleged lack of an "air clearance" in the latter (Compl. p. 10). The following chart summarizes the Plaintiffs' arguments for non-infringement of Claim 1 of the ’628 Patent.

'628 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality (as argued by Plaintiffs for non-infringement) Complaint Citation Patent Citation
an air clearance with uniform thickness is arranged between a surface of the sealed chamber interlayer close to the touch screen and the touch screen Plaintiffs' products lack an air clearance; the touch screen is alleged to be in "close contact with the sealed chamber interlayer." ¶¶18, 19, 36 col. 14:56-61
and the air clearance communicates with a charging/discharging device outside the sealing device Plaintiffs' products do not include or communicate with any charging/discharging device. ¶¶18, 36 col. 14:61-64
  • Identified Points of Contention:
    • Scope Questions: The dispute centers on the presence of two limitations in the accused products: the "air clearance" and the communicating "charging/discharging device." The complaint’s position is that these claim elements are entirely absent from the accused products (Compl. ¶36). The primary legal question will be whether any feature or structure in the accused products can be construed to meet these limitations, either literally or under the doctrine of equivalents.
    • Technical Questions: A dispositive factual question will be whether a material gap exists between the accused products' protective layer and the smartphone screen that could constitute an "air clearance." The complaint's assertion of "close contact" (Compl. ¶19) suggests a direct physical interface, a fact that would need to be verified through technical inspection of the products themselves.

V. Key Claim Terms for Construction

  • The Term: "air clearance with uniform thickness"

    • Context and Importance: This term is foundational to the dispute, as Plaintiffs' non-infringement case is predicated on the absence of this structure in their products (Compl. ¶¶18, 36). Its construction will determine whether any incidental or microscopic gap satisfies the limitation.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: A party seeking a broader definition might argue that any intentionally created and maintained separation between the interlayer and the screen constitutes a "clearance," and that "uniform" does not require mathematical perfection but rather a generally consistent spacing.
      • Evidence for a Narrower Interpretation: The patent consistently links the "air clearance" to the function of pressure equalization via a "charging/discharging device" (’628 Patent, col. 3:31-35; Claim 1). This functional relationship suggests the term describes not just any gap, but an engineered component of a pressure-balancing system. The specification also provides a preferred thickness range of "0-0.8 mm," implying a tangible, measurable space designed for a specific purpose (’628 Patent, col. 12:66-67).

  • The Term: "communicates with a charging/discharging device"

    • Context and Importance: This limitation is the second pillar of Plaintiffs' non-infringement argument (Compl. ¶18). If a structure is found to be an "air clearance," the infringement analysis will then turn on whether that structure is connected to a component meeting the definition of a "charging/discharging device."
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The specification discloses embodiments where the device is one or more "sealed and soft airbags" (’628 Patent, col. 12:15-17). A broad reading might assert that any flexible, air-filled component of the case that has an effect on the pressure within the clearance "communicates" with it.
      • Evidence for a Narrower Interpretation: The detailed description portrays a specific system where an airbag connects to the clearance via an "air pipe" and "connectors" to actively manage pressure (’628 Patent, col. 12:20-25). This may support a narrower construction requiring a dedicated and direct fluidic connection for the purpose of active pressure regulation.

VI. Other Allegations

  • Indirect Infringement: The complaint seeks a declaratory judgment of non-infringement as to inducement and contributory infringement, based on the predicate argument that there is no direct infringement by any party (Compl. ¶37).
  • Willful Infringement: While Plaintiffs are not accused of willfulness in this declaratory judgment action, they have lodged allegations of bad faith against the Defendants. The complaint includes counts for "Patent Misuse" and "Common Law Tortious Interference with Contractual Relations," alleging Defendants knew their infringement claims were baseless and initiated the APEX proceeding with the intent to harm Plaintiffs' business by having their products delisted from Amazon (Compl. ¶¶41-42, 55).

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

  • A core issue will be one of structural presence: do the accused products, as a matter of fact, incorporate a physical gap between their protective screen and the device that meets the definition of the claimed "air clearance," or is the interface one of direct contact as Plaintiffs allege?
  • A key legal question will be one of functional scope: does a proper construction of Claim 1 require the "air clearance" and "charging/discharging device" to be interpreted as an integrated, active pressure-balancing system, as detailed in the patent’s preferred embodiments, or can the claim language read on structures that lack this specific functionality?
  • Finally, the case raises a significant question of proper enforcement: did the Defendants engage in patent misuse or tortious interference by leveraging Amazon's APEX program to assert a patent they allegedly knew, or reasonably should have known, was not infringed by the accused products?