DCT
1:25-cv-23734
Voltstar Tech Inc v. Yuncheng Shiyanhu Qu Xutaowangluo Keji Youxian Gongsi
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Voltstar Technologies, Inc. (Illinois)
- Defendant: Yuncheng Shiyanhu Qu Xutaowangluo Keji Youxian Gongsi a/k/a Boonplus (China)
- Plaintiff’s Counsel: Sriplaw PLLC
- Case Identification: 1:25-cv-23734, S.D. Fla., 08/19/2025
- Venue Allegations: Plaintiff alleges venue is proper because the defendant is not a resident of the United States and has committed acts of infringement in the district.
- Core Dispute: Plaintiff alleges that Defendant’s compact USB wall chargers infringe a patent related to the specific size, shape, and construction of such power adapters.
- Technical Context: The technology relates to AC-to-DC power converters, commonly used for charging mobile phones and other portable electronics, designed to be small enough not to obstruct adjacent electrical outlets.
- Key Procedural History: The patent-in-suit, U.S. Reissue Patent No. RE48,794 E, is a reissue of U.S. Patent No. 9,024,581. The complaint notes that the reissue proceeding amended Claim 1 to narrow its scope by adding a specific width limitation ("a width of the housing outer profile being less than 1.75 inches") to the existing length limitation.
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 | U.S. Reissue Patent No. 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 section describes problems with prior art power adapter plugs being bulky, often blocking adjacent electrical outlets (’794 Patent, col. 1:42-49). It also notes that manufacturing methods like insert-molding blades into the plastic housing and hand-soldering connections were complex, time-consuming, and costly, contributing to larger package sizes (’794 Patent, col. 2:1-31).
- The Patented Solution: The invention is a "reduced plug-size charger plug" that uses a simplified construction to achieve a smaller form factor (’794 Patent, Abstract). Instead of insert-molding, the electrical blades are slidably mounted into a clamshell housing, and solder-less spring contacts are used to electrically connect the blades to the internal power conversion circuitry (’794 Patent, col. 3:14-23; Fig. 3). This design purports to reduce manufacturing complexity and, critically, results in a charger with specific, compact dimensions intended to avoid interference with adjacent outlets (’794 Patent, col. 13:40-48).
- Technical Importance: The claimed solution addresses a persistent consumer issue in a market with increasing numbers of personal electronic devices, where outlet space is often at a premium.
Key Claims at a Glance
- The complaint asserts infringement of at least Claim 1 (’794 Patent, col. 13:17 - col. 14:53; Compl. ¶29).
- The essential elements of independent Claim 1 include:
- 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 for a removable power cord.
- A specific size limitation: a longitudinal length of less than 2.0 inches and a width of the housing outer profile being less than 1.75 inches.
- A functional limitation: the outer profile having "no interference with an adjacent receptacle" when plugged into a standard wall outlet.
III. The Accused Instrumentality
Product Identification
- The complaint accuses various USB wall chargers sold under the "boonplus" brand on Amazon.com (Compl. ¶21). The complaint identifies specific models by their Amazon Standard Identification Number (ASIN), including B0995MV494 and B0C2BVQYNB (Compl. ¶21).
Functionality and Market Context
- The accused products are described as AC-to-DC power converters ("chargers") that connect between a wall outlet and a device like a mobile phone to provide charging power (Compl. ¶22). The complaint alleges these chargers employ a "reduced plug-size" design so that they do not block or interfere with the use of adjacent outlets when plugged in (Compl. ¶23). A table in the complaint lists several accused products, such as the "USB Wall Charger, Small iPhone Charger Box, Travel Plug Cube 5W Power Adapter" (Compl. ¶21).
IV. Analysis of Infringement Allegations
RE48,794 E Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a charger plug...to convert 120V input power received from the power source to DC output power... | Defendant's products are advertised and sold as chargers to be connected between an AC power source (wall outlet) and a device to provide DC power. | ¶22 | col. 13:18-23 |
| a housing...first and second separate blade members secured within the housing so as to have prong portions of the blade members positioned in order to extend...from a front wall of the housing | The accused products are charger plugs with a housing and prongs that extend from a front wall for insertion into an outlet. | ¶21, ¶23 | col. 13:26-31 |
| the charger plug including a DC connector having an aperture adapted to removably receive a corresponding power cord plug end for transmitting DC power... | The accused chargers have a USB port into which a power cord can be inserted and removed. | ¶24 | col. 13:32-36 |
| i) being sized so that the charger plug housing comprises a longitudinal length extending between the front wall and the rear end and the longitudinal length is less than 2.0 inches, a width of the housing outer profile being less than 1.75 inches | The complaint alleges the reissued patent was amended to include these specific sizing dimensions, and accuses products that it alleges meet these criteria. | ¶12 | col. 14:38-44 |
| ii) the outer profile having no interference with an adjacent receptacle of the power source located on all sides of the first receptacle when a like charger plug is mounted in all available orientations... | The complaint alleges the accused chargers "do not block or interfere with the use of adjacent outlets." | ¶23 | col. 14:45-50 |
- Identified Points of Contention:
- Scope Questions: A central question may be the interpretation of the functional limitation "no interference with an adjacent receptacle." The dispute could turn on what constitutes "interference"—whether it means any physical contact with a neighboring plug, or only contact that prevents a standard plug from being fully inserted and used.
- Technical Questions: The infringement analysis will likely depend on factual evidence regarding the precise physical dimensions of the accused products. A key question for the court will be whether the "longitudinal length" and "width of the housing outer profile" of the accused "boonplus" chargers, when measured, are in fact less than the 2.0-inch and 1.75-inch thresholds required by the claim.
V. Key Claim Terms for Construction
The Term: "outer profile"
Context and Importance: This term is critical because it defines the boundaries of the housing that are subject to the specific length and width limitations of Claim 1(i). The definition of "outer profile" will determine how the accused products are measured and whether they fall within the claimed dimensions.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: A party might argue that "outer profile" should be given its plain and ordinary meaning, encompassing the maximum dimensions of the housing at any point, including any slight protrusions or curved surfaces.
- Evidence for a Narrower Interpretation: A party could point to the patent's figures (e.g., Figs. 1, 10, 15) and the description of the housing's shape as generally radiused or tapered to argue that the "profile" refers to the main body of the charger, potentially excluding incidental features (’794 Patent, col. 8:63-65).
The Term: "no interference with an adjacent receptacle"
Context and Importance: This functional language in Claim 1(ii) is a primary basis for the non-obviousness and utility of the invention. Its construction will likely be dispositive for infringement, as it sets the performance standard the accused product must meet.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: Plaintiff may argue this term means that the housing cannot physically touch any part of a standard plug inserted into an adjacent outlet, pointing to the patent's goal of completely avoiding the problems of oversized chargers (’794 Patent, col. 1:42-49).
- Evidence for a Narrower Interpretation: Defendant may argue that "interference" should be construed more narrowly to mean only obstruction that prevents an adjacent plug from being inserted and making a functional electrical connection, as this is the core problem the patent sought to solve.
VI. Other Allegations
- Indirect Infringement: The complaint does not include specific counts for indirect or contributory infringement.
- Willful Infringement: The complaint makes a conclusory allegation that Defendant had "actual or constructive knowledge" of Plaintiff's intellectual property rights (Compl. ¶20) and includes a request for enhanced damages for willful infringement in the prayer for relief (Prayer for Relief ¶C). However, the complaint does not plead specific facts demonstrating pre-suit knowledge of the patent-in-suit.
VII. Analyst’s Conclusion: Key Questions for the Case
The resolution of this dispute may turn on two central questions:
- A core issue will be one of factual measurement: Do the accused "boonplus" chargers physically conform to the precise dimensional limitations of Claim 1, namely a longitudinal length less than 2.0 inches and a width less than 1.75 inches? The case may depend heavily on expert testimony regarding the proper methodology for measuring the "outer profile" of the accused devices.
- A key legal question will be one of functional scope: How will the court construe the term "no interference with an adjacent receptacle"? Whether this limitation is interpreted as an absolute prohibition on any physical contact with a neighboring plug, or a more practical standard of not preventing the use of that outlet, will be critical in determining infringement.