Shenzhen Jisu Technology Co Ltd v. Shenzhen Fosala Technology Co Ltd

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Shenzhen Jisu Technology Co., Ltd. (China)
  • Defendant: Shenzhen Fosala Technology Co., Ltd., et al. (China)
  • Plaintiff’s Counsel: Sills Cummis & Gross P.C.
• Case Identification: 2:25-cv-16605, D.N.J., 02/24/2026
• Venue Allegations: Plaintiff alleges venue is proper because the Defendants target consumers in the United States, including New Jersey, through interactive e-commerce stores, offer shipping to the state, accept payment in U.S. dollars, and solicit reviews from and accept returns from customers in New Jersey.
• Core Dispute: Plaintiff alleges that Defendants’ sale of various models of personal neck fans infringes one utility patent and one design patent related to wearable, bladeless fan technology.
• Technical Context: The dispute concerns the market for personal cooling devices, specifically wearable neck fans that provide hands-free cooling and are popular on e-commerce platforms.
• Key Procedural History: The complaint details a complex commercial history between the parties, including a 2022 licensing agreement and subsequent 2025 agreements. Plaintiff alleges that the '602 patent was licensed under the 2025 agreements, which Defendants subsequently breached by failing to pay royalties, leading to termination. Plaintiff further alleges Defendants created new corporate entities to continue selling accused products while avoiding royalty obligations.

Case Timeline

Date	Event
2019-10-25	’602 Patent Priority Date
2020-09-07	’D932 Patent Filing Date
2021-08-24	’D932 Patent Issue Date
2022-01-27	2022 Licensing Agreement Executed
2024-03-05	’602 Patent Issue Date
2025-01-01	2025 Licensing Agreements Effective
2025-06-23	2025 Agreements Termination Notice via Text
2025-08-12	2025 Agreements Termination Notice via Letter
2026-02-24	Complaint Filing Date

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

U.S. Patent No. 11,920,602 - “Neck Fan”

• Patent Identification: U.S. Patent No. 11,920,602 B2, titled “Neck Fan,” issued on March 5, 2024.

The Invention Explained

• Problem Addressed: The patent describes conventional neck fans as having exposed fan blades, creating safety risks such as hair entanglement, and producing concentrated, uncomfortable streams of air (U.S. Patent No. 11,920,602, col. 1:35-41).
• The Patented Solution: The invention is a wearable neck fan with fan assemblies enclosed within a shell composed of inner and outer walls (U.S. Patent No. 11,920,602, abstract). This shell forms an internal "receiving space" which also functions as an air duct (U.S. Patent No. 11,920,602, col. 1:43-54). Air is drawn into the shell through inlets, propelled by the internal fan assemblies through the air duct, and expelled through a plurality of outlets towards the user, creating a safer and more distributed airflow (U.S. Patent No. 11,920,602, abstract).
• Technical Importance: This design approach seeks to improve both the safety and user comfort of wearable fans by enclosing the moving parts and diffusing the resulting airflow.

Key Claims at a Glance

• The complaint asserts independent Claim 1 (Compl. ¶46).
• The essential elements of Claim 1 include:
  • A neck fan comprising an inner shell and an outer shell that cooperatively define a receiving space.
  • A plurality of fan assemblies received within the receiving space.
  • The inner shell defining a plurality of air inlets located near and facing towards the neck.
  • At least part of the receiving space serving as an air duct that communicates with the air inlets.
  • Each fan assembly configured to intake air through the corresponding air inlets and drive it into the air duct.
• The complaint reserves the right to assert additional claims (Compl. ¶46).

U.S. Design Patent No. D928,932 - “Fan”

• Patent Identification: U.S. Patent No. D928,932 S, titled “Fan,” issued on August 24, 2021.

The Invention Explained

• Problem Addressed: Design patents protect the ornamental appearance of an article of manufacture rather than its utilitarian features. The patent addresses the creation of a new, original, and ornamental design for a neck fan.
• The Patented Solution: The patent claims the specific visual appearance of a neck fan as depicted in its drawings (U.S. Design Patent No. D928,932, Figs. 1-16). Key ornamental features include the device's overall U-shape, the continuous band of slit-like air outlets along the top inner curvature, the smooth, unadorned exterior surface of the main body, and the distinct circular housings at each end of the device (U.S. Design Patent No. D928,932, Fig. 1).
• Technical Importance: Not applicable; the value is in the aesthetic and ornamental design.

Key Claims at a Glance

• Design patents contain a single claim for the ornamental design as shown and described (U.S. Design Patent No. D928,932, claim). The complaint asserts this claim (Compl. ¶¶56-57).

III. The Accused Instrumentality

Product Identification

• The accused products are the M5, R5, S10, S9, and M15 model neck fans (Compl. ¶24).

Functionality and Market Context

• The complaint identifies the accused products as wearable, personal cooling fans sold by the Defendants through online marketplaces such as Amazon and Walmart (Compl. ¶21; Compl. ¶24). An image provided in the complaint depicts the "M5 Neck Fan" as a U-shaped device worn around the neck with air outlets positioned to direct air toward the user's head (Compl., p. 8). The complaint alleges these products are manufactured by Defendant SMT and sold by the other "FoSala Defendants" (Compl. ¶24).

IV. Analysis of Infringement Allegations

The complaint references claim charts attached as exhibits to a prior filing, which were not provided for this analysis (Compl. ¶46; Compl. ¶56). The infringement theory is therefore summarized from the complaint's narrative allegations.

For the ’602 Patent, the complaint alleges that the Accused Products meet each limitation of at least Claim 1 (Compl. ¶46). This suggests the Accused Products are alleged to possess an inner and outer shell structure that encloses fan assemblies and defines an air duct, with air being drawn in through inlets and expelled through outlets.

For the ’D932 Patent, the complaint alleges that the M5 neck fan, in particular, is "substantially similar to, or at least a colorable imitation of the claimed design" (Compl. ¶56). This allegation is based on the "ordinary observer" test for design patent infringement, which centers on the overall visual similarity between the accused product and the patented design. An image in the complaint shows the accused "M5" product, allowing for a visual comparison to the design patent figures (Compl., p. 8).

• Identified Points of Contention:
  • Scope Questions (’602 Patent): A central dispute may arise over the claim limitation requiring "a plurality of air inlets, located near and facing towards the neck." This specifies a potentially counterintuitive location for air intake (from the inner surface of the device). The defense may argue that the accused products draw air from the sides or outer surfaces, which would create a direct mismatch with the language of Claim 1.
  • Technical Questions (’D932 Patent): The infringement analysis will turn on a visual comparison. The defense may highlight differences in the proportions of the device, the specific pattern and shape of the air outlets, or the design of the end housings to argue that an ordinary observer would not find the designs to be substantially the same.

V. Key Claim Terms for Construction

• The Term: "a plurality of air inlets, located near and facing towards the neck" (’602 Patent, Claim 1)
• Context and Importance: The location of the air inlets is a fundamental and specific aspect of the claimed invention. The construction of this phrase is critical, as a narrow interpretation would require Plaintiff to prove the accused products draw air from the inner surface of the fan, which may not be the case.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: A party might argue that "near" is a relative term and any inlet on a surface that is generally part of the inner curvature of the device meets this limitation.
  • Evidence for a Narrower Interpretation: Claim 8 of the patent separately claims an embodiment where inlets are on the outer shell ("disposed away from and facing away from the neck") (’602 Patent, col. 16:60-62). The existence of this distinct claim suggests that Claim 1 was intentionally drafted to be limited to inlets on the inner shell. The specification also explicitly describes an embodiment where "air inlets 108 are defined in the inner wall 101" (’602 Patent, col. 8:41-43), providing further support for a narrow construction.

VI. Other Allegations

• Indirect Infringement: The complaint alleges that all Defendants induced infringement by encouraging consumers to use the accused products in the United States (Compl. ¶48; Compl. ¶58).
• Willful Infringement: The complaint asserts a strong basis for willfulness regarding the ’602 Patent, alleging that Defendants had actual knowledge because the patent was expressly identified in the 2025 Licensing Agreements that Defendants are alleged to have breached (Compl. ¶51). For the ’D932 Patent, the allegation is more general, stating Defendants "have been aware" of the patent (Compl. ¶61). Plaintiff provides a screenshot from its website explicitly listing its patents, including the ’602 Patent, as a form of public notice (Compl., p. 6, Fig. 2).

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

• A core issue will be one of technical infringement: for the ’602 patent, can Plaintiff prove that the accused products possess the specific air intake structure required by Claim 1, namely "air inlets, located near and facing towards the neck," or will that limitation prove to be a fatal flaw in its infringement theory?
• A second key issue will be one of visual identity: for the ’D932 patent, is the overall ornamental appearance of the accused M5 fan "substantially the same" as the patented design in the eyes of an ordinary observer, or are there sufficient visual differences to distinguish them?
• Finally, a central question for damages will be the impact of the parties' commercial history: given the detailed allegations of licensing, breach of contract, and the creation of shell companies, how will this complex factual background influence the court’s assessment of willfulness and the appropriate measure of damages?