DCT

1:25-cv-23728

Voltstar Tech Inc v. Lei Tongshuai

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:25-cv-23728, S.D. Fla., 08/19/2025
  • Venue Allegations: Venue is asserted on the basis that the defendant is not a U.S. resident and has committed acts of infringement in the district.
  • Core Dispute: Plaintiff alleges that Defendant’s power adapter products, sold online, infringe a reissued patent related to the specific dimensional and structural characteristics of compact electrical chargers.
  • Technical Context: The technology concerns the design and manufacturing of small form-factor AC-to-DC power adapters, a ubiquitous component in the consumer electronics market.
  • Key Procedural History: The asserted patent, RE48,794 E, is a reissue of U.S. Patent No. 9,024,581. The complaint notes that Claim 1 was amended during reissue to narrow its scope by changing a length limitation from "equal to or less than 2.0 inches" to strictly "less than 2.0 inches" and by adding a new width limitation of "less than 1.75 inches." This amendment may have implications for claim scope and potential intervening rights defenses.

Case Timeline

Date Event
2008-05-21 Priority Date for U.S. Patent No. 9,024,581
2015-05-05 U.S. Patent No. 9,024,581 Issued
2021-10-26 Reissue Patent RE48,794 E Issued
2025-08-19 Complaint Filed

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

U.S. Reissue Patent No. RE48,794 E - "Charger Plug With Improved Package"

The Invention Explained

  • Problem Addressed: The patent's background describes several problems with prior art electrical chargers: they are often bulky, blocking adjacent wall outlets; their length can prevent placement of furniture near the outlet; and their manufacturing, particularly the process of "insert molding" electrical blades into a plastic housing, is costly, time-consuming, and prone to error (RE48,794 E, col. 1:42-col. 2:11).
  • The Patented Solution: The invention proposes a compact charger design with a specific housing structure and internal component layout that solves these issues. It uses separate electrical blades that are slidably mounted into the housing rather than insert-molded, simplifying assembly (RE48,794 E, Abstract). This design, coupled with solder-less spring contacts connecting the blades to the internal circuit board, allows for a reduced package size with specific dimensional limitations that avoid interference with adjacent outlets (RE48,794 E, col. 4:1-15; Fig. 1).
  • Technical Importance: The described solution aims to reduce manufacturing costs and complexity while creating a smaller, more user-friendly charger profile that is less obtrusive in crowded power strips or behind furniture (RE48,794 E, col. 1:42-58).

Key Claims at a Glance

  • The complaint asserts infringement of at least Claim 1 (Compl. ¶29).
  • Independent Claim 1 of the RE48,794 E patent requires:
    • A charger plug for converting 120V input power to DC output power.
    • A housing containing first and second separate blade members with prong portions.
    • A DC connector with an aperture to receive a power cord.
    • A housing forming a charger plug face area and an outer profile.
    • i) The housing being sized with a longitudinal length less than 2.0 inches and a width of the housing outer profile being less than 1.75 inches.
    • ii) The outer profile having no interference with an adjacent receptacle of a power source.

III. The Accused Instrumentality

Product Identification

  • A series of power adapters sold under the brand name "SMAYS" on Amazon.com, identified by various ASINs and product names such as "2-Pack Power Adapter Compatible with Outdoor WYZE Cam..." (Compl. ¶21).

Functionality and Market Context

  • The complaint alleges the accused products are chargers designed to be connected between an AC power source (like a wall outlet) and a DC-powered device (Compl. ¶22).
  • The core accused functionality relates to the physical size and shape of the chargers, which allegedly employ a "reduced plug-size" design that "do[es] not block or interfere with the use of adjacent outlets" (Compl. ¶23). The complaint also alleges the products are shaped to allow for easy insertion and removal of a power cord without removing the charger from the wall (Compl. ¶24).

IV. Analysis of Infringement Allegations

The complaint references a claim chart in its Exhibit 3, which was not provided with the filing (Compl. ¶25, 29). The infringement theory must therefore be summarized from the narrative allegations in the complaint body.

The complaint alleges that the Defendant's chargers meet the limitations of Claim 1 of the RE48,794 E Patent (the "'794 Patent"). The narrative alleges the accused products are chargers that connect between an AC source and a DC device (Compl. ¶22). It further alleges that the products have a "reduced plug-size" and specific "size and shape" such that they do not block adjacent outlets and allow for easy insertion and removal of a power cord (Compl. ¶23-24). These allegations map to the functional and dimensional limitations of Claim 1. However, the complaint does not provide specific measurements for the accused products to substantiate infringement of the explicit "less than 2.0 inches" length and "less than 1.75 inches" width limitations recited in Claim 1(i).

No probative visual evidence provided in complaint.

  • Identified Points of Contention:
    • Scope Questions: A central dispute may revolve around the interpretation of "outer profile having no interference with an adjacent receptacle." This functional language could be subject to construction, raising questions about what constitutes "interference" under various standard outlet configurations.
    • Technical Questions: The primary factual question will be whether the accused SMAYS chargers actually meet the precise dimensional limitations of Claim 1(i). The complaint makes a general allegation of a "reduced plug-size" but does not offer specific measurements, which will be a necessary element of proof (Compl. ¶23).

V. Key Claim Terms for Construction

  • The Term: "a width of the housing outer profile being less than 1.75 inches"
  • Context and Importance: This limitation, along with the length limitation, was added during the reissue proceeding that converted the '581 patent into the '794 Patent (Compl. ¶12 & fn.1). Its construction is critical because it represents a deliberate narrowing of the claim scope. The method of measuring the "width" of the "outer profile" on an object that may have curved or irregular sides could become a point of contention.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification provides context that the overall goal is to "not interfere with use of an adjacent plug" (RE48,794 E, col. 12:12-15). A party might argue that any reasonable measurement method that achieves this functional goal should suffice.
    • Evidence for a Narrower Interpretation: The patent provides a specific numerical value ("1.75 inches") and uses precise language ("width of the housing outer profile") (RE48,794 E, col. 13:45-49). A party could argue this requires a specific, standardized measurement of the widest lateral point of the housing body, irrespective of the functional outcome in any single use case. The prosecution history of the reissue, which led to the addition of this term, would be highly relevant extrinsic evidence.

VI. Other Allegations

  • Willful Infringement: The complaint alleges that the defendant had "actual or constructive knowledge" of Plaintiff's rights (Compl. ¶20) and asks for a determination of willful infringement in its prayer for relief (Compl. Prayer ¶C). However, the complaint does not plead specific facts indicating when or how the Defendant became aware of the '794 Patent prior to the lawsuit.

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

  1. A core issue will be one of evidentiary proof: Can the Plaintiff demonstrate, through testing and measurement, that the accused SMAYS products meet the explicit numerical dimension limitations ("less than 2.0 inches" in length and "less than 1.75 inches" in width) added to Claim 1 during the patent's reissue?
  2. A secondary issue will be one of claim construction: How will the court define the measurement protocol for the "width of the housing outer profile," and how will it interpret the functional requirement that the profile has "no interference with an adjacent receptacle"? The outcome of these construction questions could determine the scope of the asserted claim.
  3. A potential defensive issue may arise from the reissue history: Given that the key claim limitations were added during reissue to narrow the patent, the Defendant may scrutinize the prosecution history for arguments of non-infringement or explore the possibility of intervening rights under 35 U.S.C. § 252 for any conduct that occurred before the reissue patent was granted.