DCT

1:26-cv-11783

Shenzhen Lingyi Innovation Technology Co Ltd v. Shenzhen Benks Technology Co Ltd

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Complaint
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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:26-cv-11783, N.D. Ill., 09/25/2026
  • Venue Allegations: Venue is alleged to be proper because all defendants are foreign corporations not resident in the United States, and thus may be sued in any judicial district under the alien-venue rule. The complaint also alleges venue is proper and convenient due to defendants' sales and shipments into the Northern District of Illinois.
  • Core Dispute: Plaintiffs allege that Defendants’ BENKS-branded smartphone protective cases infringe two U.S. patents related to a precision camera-ring mounting architecture and a multi-layer case construction for magnetic charging.
  • Technical Context: The lawsuit concerns the highly competitive market for premium smartphone cases, where technical innovations in camera protection, slim profiles, and compatibility with accessories like magnetic chargers are key differentiators.
  • Key Procedural History: The complaint alleges that Plaintiffs have complied with statutory marking requirements for their own products. It also alleges a complex corporate structure for the defendants, operating as a "common enterprise" to manufacture, import, and sell the accused products in the U.S. through various Amazon storefronts.

Case Timeline

Date Event
2022-08-11 '528 Patent Priority Date
2023-09-07 '787 Patent Priority Date
2024-04-30 U.S. Patent No. 11,973,528 Issued
2025-02-11 U.S. Patent No. 12,224,787 Issued
2026-06 Accused Product ordered by Plaintiffs' agent for delivery to Illinois Compl. ¶14
2026-07 Accused Product ordered by Plaintiffs' agent for delivery to Illinois Compl. ¶14
2026-09-24 Accused Product ordered by Plaintiffs' agent for delivery to Illinois Compl. ¶14
2026-09-25 Complaint Filed

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

U.S. Patent No. 11,973,528 - "Protective Case for Portable Electronic Device"

Issued on April 30, 2024.

The Invention Explained

  • Problem Addressed: The patent’s background section describes an issue with multi-part protective cases where a separately installed camera decorative ring protrudes from the inner side of the case, causing deformation that can compromise the fit on the electronic device and interfere with accessories like chargers or brackets '528 Patent, col. 1:28-46
  • The Patented Solution: The invention proposes a two-part construction where the main rear shell has a groove around its camera opening, and the separate camera ring has a corresponding "limit part" that embeds into that groove '528 Patent, col. 3:20-46 A key aspect is that the inner surface of the camera ring is designed to be "evenly aligned with or lower than the inner surface of the back plate," which prevents the ring from protruding inward and causing the problematic deformation '528 Patent, abstract '528 Patent, Fig. 8
  • Technical Importance: This mechanical interlocking design aims to create a more stable and precise fit for protective cases with large, separate camera rings, improving both device protection and compatibility with other accessories '528 Patent, col. 3:1-19

Key Claims at a Glance

  • The complaint asserts infringement of at least independent claim 11 Compl. ¶46
  • Claim 11 requires:
    • A rear shell and a camera decorative ring.
    • The rear shell has a back plate with an avoidance hole, and a "first limit part" is formed between the outer surface of the back plate and the inner wall of the avoidance hole.
    • The camera decorative ring has an outer peripheral surface with a "retention groove," in which the "first limit part" is embedded.
    • The inner end surface of the camera decorative ring is "lower than the inner surface of the back plate."
    • The inner peripheral surface of the camera decorative ring has a "first avoidance surface" that is "tapered from inside to outside."

U.S. Patent No. 12,224,787 - "Protective Case for Electronic Device"

Issued on February 11, 2025.

The Invention Explained

  • Problem Addressed: The patent’s background section explains the difficulty in creating thin phone cases that can securely hold magnets for wireless charging '787 Patent, col. 1:19-24 If magnets are simply glued into a groove, they can be pushed out; adding a protective layer like flannel to hold them in place adds undesirable bulk '787 Patent, col. 1:25-44
  • The Patented Solution: The invention describes a multi-layer case comprising a decorative outer layer, a functional inner layer with an embedded magnet, and two distinct coatings '787 Patent, abstract A first coating is applied to the outer surface for aesthetics and protection, while a second, inner coating (e.g., of epoxy) is applied over the functional layer, completely covering the magnet and its mounting hole to secure it in place without adding significant thickness '787 Patent, col. 2:1-15 '787 Patent, Fig. 1B
  • Technical Importance: This layered construction method allows for the manufacture of thin and lightweight protective cases that can reliably integrate magnetic components for wireless charging functionality '787 Patent, col. 1:45-54

Key Claims at a Glance

  • The complaint asserts infringement of at least independent claim 10 Compl. ¶53
  • Claim 10 requires:
    • A decorative layer with an outer surface provided with a first coating, where the first coating is "applied by spraying a surface treatment agent."
    • A functional layer with an inner surface provided with a second coating that "completely cover[s] the mounting hole."
    • The second coating is formed of at least one of polyester, polyethylene, polypropylene, or epoxy materials.
    • The first coating has a thickness that ranges from 0.01 mm to 0.10 mm.
    • The second coating has a thickness that ranges from 0.05 mm to 0.28 mm.

III. The Accused Instrumentality

Product Identification

The accused products are BENKS-branded smartphone protective cases, including the "ArmorPro," "Montage ArmorPro," "Prestige ArmorPro," "ArmorGrid ArmorPro," "Aurora ArmorPro," "ArmorAir," and "Aurora ArmorAir" product lines Compl. ¶35

Functionality and Market Context

The complaint alleges that the Accused Products are direct, head-to-head competitors to Plaintiffs' PITAKA-branded cases in the U.S. market for premium magnetic phone cases Compl. ¶23 Plaintiffs' investigation, which reportedly included physical inspection and laboratory analysis, concluded that the Accused Products incorporate the patented technologies Compl. ¶38 Specifically, they are alleged to have a rear shell and separate camera ring with interlocking structures Compl. ¶39 and a layered construction with an embedded magnet and specific coatings of certain thicknesses Compl. ¶40

No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

'528 Patent Infringement Allegations

Claim Element (from Independent Claim 11) Alleged Infringing Functionality Complaint Citation Patent Citation
a rear shell and a camera decorative ring The Accused Products include a rear shell and a separate camera decorative ring. ¶47 col. 3:20-23
a first limit part is formed between the outer surface of the back plate and the inner wall surface of the avoidance hole The Accused Products have a "first limit part on the back plate." ¶47 col. 7:45-48
the outer peripheral surface of the camera decorative ring is provided with a retention groove, the first limit part is embedded in the retention groove The "first limit part" is embedded in a "retention groove on the ring's outer peripheral surface." ¶47 col. 7:49-55
the inner end surface of the camera decorative ring is lower than the inner surface of the back plate The ring's inner end surface is lower than the inner surface of the back plate. ¶47 col. 7:55-57
the inner peripheral surface of the camera decorative ring has a first avoidance surface, the first avoidance surface is tapered from inside to outside The ring's inner peripheral surface has a "first avoidance surface...tapered from inside to outside." ¶47 col. 7:36-39
  • Identified Points of Contention:
    • Structural Correspondence: A central question may be whether the accused product's structure perfectly maps onto the claim's specific definition of a "first limit part" being "formed between the outer surface of the back plate and the inner wall surface of the avoidance hole." The precise geometry and location of this interlocking feature will be a focus.
    • Evidentiary Support: The complaint states its allegation regarding the "tapered first avoidance surface" is based on initial inspection and "is likely to have additional evidentiary support after a reasonable opportunity for further investigation" Compl. ¶47 This suggests that the exact angle and nature of this taper may be a point of dispute requiring detailed measurement and expert testimony.

'787 Patent Infringement Allegations

Claim Element (from Independent Claim 10) Alleged Infringing Functionality Complaint Citation Patent Citation
the decorative layer has an outer surface that is provided with a first coating, and the first coating is applied by spraying a surface treatment agent The Accused Products have an "outer first coating" which Plaintiffs allege on information and belief is applied by spraying a surface treatment agent. ¶40; ¶54 col. 15:3-5
the functional layer has an inner surface that is provided with a second coating, with the second coating completely covering the mounting hole The Accused Products have an "inner second coating" that "completely cover[s] the mounting hole." ¶40 col. 13:8-10
the second coating is formed of at least one of polyester, polyethylene, polypropylene, or epoxy materials The second coating was identified via Fourier Transform Infrared Spectroscopy as "epoxy resin." ¶40 col. 13:10-12
the first coating has a thickness that ranges from 0.01 mm to 0.10 mm The first coating was measured on purchased units and found to be within the claimed thickness range. ¶40; ¶54 col. 13:14-15
the second coating has a thickness that ranges from 0.05 mm to 0.28 mm The second coating was measured on purchased units and found to be within the claimed thickness range. ¶40; ¶54 col. 13:17-19
  • Identified Points of Contention:
    • Process Limitation: Claim 10 includes a process limitation, requiring the first coating to be "applied by spraying a surface treatment agent." The complaint acknowledges this is "a fact within Defendants' exclusive knowledge and confirmable through discovery" Compl. ¶54 Proving this specific manufacturing step, as opposed to other methods of applying a coating, may present an evidentiary hurdle for the Plaintiffs.
    • Quantitative Analysis: The infringement allegation relies on the thicknesses of two separate coatings falling within specific numerical ranges. While the complaint asserts this based on its investigation Compl. ¶40, the case will likely involve conflicting expert analysis and metrology data to determine if the accused products meet these precise quantitative limitations.

V. Key Claim Terms for Construction

  • Term ('528 Patent): "first limit part"

    • Context and Importance: This term defines the key interlocking structure on the rear shell that engages the camera ring. The existence and specific location of a corresponding structure in the accused product is fundamental to the infringement allegation for the '528 Patent. Practitioners may focus on this term because its construction will dictate the scope of the required physical geometry.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The specification describes the function of the limit part as creating "a stable fitting" and a "two-way limit" '528 Patent, col. 3:19-23 This functional language may support an interpretation that covers any structure on the shell that achieves this interlocking purpose, regardless of its exact shape.
      • Evidence for a Narrower Interpretation: The patent depicts the "first limit part" as a specific lip-like structure (element 13) formed at the junction of the back plate's outer surface and the avoidance hole's inner wall '528 Patent, Fig. 8 '528 Patent, col. 3:28-30 This may support a narrower construction limited to the specific geometry shown in the embodiments.

  • Term ('787 Patent): "surface treatment agent"

    • Context and Importance: This term is part of a manufacturing process limitation in claim 10. The infringement analysis hinges on whether the material Defendants spray on their cases qualifies as a "surface treatment agent."
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The patent lists "oil based paint, hydrophobic paint, [and] anti-fingerprint paint" as examples of materials for the first coating, which is applied by spraying the agent '787 Patent, col. 5:48-50 This may support construing the term broadly to include any sprayable paint or coating that alters the surface properties for waterproofing or aesthetics.
      • Evidence for a Narrower Interpretation: A defendant could argue that "surface treatment agent" implies more than just a layer of paint, suggesting a material that chemically or physically modifies the substrate itself. The patent does not provide a formal definition, leaving the term open to interpretation based on its ordinary meaning in the relevant technical field.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges induced infringement against Defendant Bangboshi, the alleged manufacturer Compl. ¶48 Compl. ¶55 The basis for inducement is Bangboshi's alleged acts of manufacturing the accused products, applying U.S.-specific packaging and labeling, and supplying the products to other defendants with the knowledge and specific intent that they would be imported and sold in the United States Compl. ¶48
  • Willful Infringement: The complaint alleges willful infringement based on Defendants' continued infringement after having received knowledge of the asserted patents through the filing and service of the complaint Compl. ¶51 Compl. ¶58

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

  1. A Structural Question: For the '528 Patent, a core issue will be one of structural correspondence: do the accused BENKS cases possess a "first limit part" that is geometrically and positionally consistent with the definition in claim 11, which requires it to be part of the rear shell and embed within a groove on the camera ring?
  2. An Evidentiary Question: For the '787 Patent, a key hurdle for the plaintiff will be evidentiary: can it prove, through discovery, that the defendant's manufacturing process uses the specific step of "spraying a surface treatment agent," as required by the process limitation in claim 10?
  3. A Quantitative Question: The '787 Patent infringement claim will also turn on a battle of experts regarding precise measurements. Does the thickness of the inner and outer coatings on the accused products fall within the specific numerical ranges recited in claim 10, and can this be reliably proven?