DCT
1:25-cv-06145
Voltstar Tech Inc v. Ice Tech LLC
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Voltstar Technologies, Inc. (Illinois)
- Defendant: ICE Technologies LLC (Delaware); Hudson Group (HG), Inc. (Delaware); Bluestar Alliance, LLC (New York)
- Plaintiff’s Counsel: Sriplaw PLLC
- Case Identification: 1:25-cv-06145, N.D. Ill., 09/02/2025
- Venue Allegations: Plaintiff alleges venue is proper based on Defendant ICE Technologies having a regular and established place of business in the district, and because all defendants have allegedly committed acts of infringement within the district.
- Core Dispute: Plaintiff alleges that certain Brookstone-branded AC power adapters sold by Defendants infringe a patent related to the compact physical dimensions and non-interfering design of charger plugs.
- Technical Context: The technology concerns the mechanical and electrical packaging of AC-to-DC power converters, aiming to reduce their size to prevent the blockage of adjacent electrical outlets, a common issue with consumer electronics chargers.
- Key Procedural History: The asserted patent, RE48,794, is a reissue of U.S. Patent No. 9,024,581. The complaint notes that during the reissue process, Claim 1 was amended to narrow a dimensional limitation for the charger's longitudinal length from "equal to or less than 2.0 inches" to "less than 2.0 inches." This amendment may focus the infringement analysis on products strictly smaller than 2.0 inches and could raise questions related to prosecution history estoppel or intervening rights.
Case Timeline
| Date | Event |
|---|---|
| 2008-05-21 | Earliest Priority Date ('581 Patent Filing) |
| 2015-05-05 | Original '581 Patent Issued |
| 2021-10-26 | Reissue '794 Patent Issued |
| 2025-09-02 | Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Reissue Patent No. RE48,794 E - "Charger Plug With Improved Package"
- Patent Identification: U.S. Reissue Patent No. RE48,794 E, "Charger Plug With Improved Package," issued October 26, 2021.
The Invention Explained
- Problem Addressed: The patent's background section describes problems with prior art electrical chargers, which were often bulky enough to block adjacent power outlets, had elongated designs that made them susceptible to being struck or dislodged, and involved complex and costly manufacturing processes like insert molding and hand soldering of electrical components (RE48,794 E Patent, col. 1:42-2:24).
- The Patented Solution: The invention claims to solve these problems through a charger with a reduced physical package and a simplified construction. The design features specific dimensional limitations on its length and width and is configured to avoid interfering with adjacent receptacles ('794 Patent, col. 12:11-15). The internal construction uses solder-less spring contacts to connect the power blades to the printed circuit board, which simplifies assembly and helps achieve the compact size ('794 Patent, Abstract; col. 3:15-28).
- Technical Importance: This design approach addresses a persistent issue in consumer electronics: the need for compact, portable, and unobtrusive power adapters that can be used in crowded power strips or wall outlets without impeding access to other sockets (Compl. ¶17).
Key Claims at a Glance
- The complaint asserts at least Claim 1 (Compl. ¶36).
- Independent Claim 1 of the '794 Patent includes these essential elements:
- A charger plug for converting AC power to DC power.
- A housing containing blade members for connecting to a power source and a DC connector for a power cord.
- The housing being sized with a longitudinal length of less than 2.0 inches and a width of less than 1.75 inches.
- The housing's "outer profile" having "no interference with an adjacent receptacle" of the power source.
- The complaint does not explicitly reserve the right to assert dependent claims.
III. The Accused Instrumentality
Product Identification
- The "Brookstone PD 20W Charger" and the "Brookstone AC Charger" (Compl. ¶¶20, 27).
Functionality and Market Context
- The complaint describes the accused products as AC-to-DC power chargers used to recharge battery-powered devices, such as mobile phones, from a standard wall outlet (Compl. ¶¶21, 28). The complaint includes an image of the Brookstone PD 20W Charger, showing a compact, rectangular wall adapter with two prongs (Compl. p. 6).
- A central allegation is that the products employ a "reduced plug-size" design, which allows them to be plugged into a wall outlet without blocking or interfering with the use of adjacent outlets (Compl. ¶¶22, 29). The complaint further alleges the shape and size facilitate easy insertion and removal of a power cord while the charger remains plugged in (Compl. ¶¶23, 30).
IV. Analysis of Infringement Allegations
The complaint alleges that the Accused Products directly infringe at least Claim 1 of the '794 Patent. Although the complaint references claim chart exhibits, these exhibits were not provided. The infringement theory articulated in the complaint is summarized below.
RE48,794 E Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A charger plug capable of connecting with a... power source to convert... input power received from the power source to DC output power... | The accused "Brookstone 20 W Charger" and "Brookstone AC Charger" are described as chargers that connect to an AC power source (wall outlet) to provide DC power for recharging devices like mobile phones. | ¶¶21, 28 | col. 7:23-28 |
| being sized so that the charger plug housing comprises a longitudinal length... is... less than 2.0 inches, a width of the housing outer profile being less than 1.75 inches... | The complaint alleges specific measurements: the 20W Charger has a length of ~1.926 inches and a width of ~1.331 inches; the AC Charger has a length of ~1.922 inches and a width of ~1.552 inches. | ¶¶26, 33 | col. 14:6-8 |
| the outer profile having no interference with an adjacent receptacle of the power source... | The complaint alleges that upon plugging the accused chargers into an AC power source, they do "not block or interfere with the use of adjacent outlets." The complaint includes an image of the "Brookstone AC Charger" illustrating its form factor (Compl. p. 8). | ¶¶22, 29 | col. 12:11-15 |
- Identified Points of Contention:
- Scope Questions: The functional limitation "no interference with an adjacent receptacle" may become a central point of dispute. A key question for the court could be how to construe this phrase: does it require absolute non-interference with any possible plug in an adjacent socket, or is there a "person of ordinary skill" standard for what constitutes interference in typical use?
- Technical Questions: The infringement case relies on specific dimensional measurements. A factual question will be whether the defendants' products, as manufactured and sold, consistently meet the "less than 2.0 inches" and "less than 1.75 inches" limitations. The precision and methodology of these measurements could be contested.
V. Key Claim Terms for Construction
The Term: "outer profile having no interference with an adjacent receptacle"
Context and Importance: This term defines a key functional benefit of the invention. Its construction will be critical because infringement depends not just on the charger's dimensions, but on its functional relationship with its environment (the power outlet). Practitioners may focus on this term because its scope is not explicitly defined by physical measurements alone, leaving it open to interpretation.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent background states that a goal is for the plug to provide "little or no interference" ('794 Patent, col. 1:45-47). Plaintiff may argue this context suggests the claim should not be interpreted as requiring absolute non-interference in all hypothetical scenarios.
- Evidence for a Narrower Interpretation: Claim 1 uses the absolute term "no interference." The patent later states that "the plug 10 does not interfere with use of an adjacent plug" ('794 Patent, col. 12:11-12). Defendant may argue this language, combined with the patent's goal of solving the blocking problem, requires a strict, literal interpretation where the charger's physical profile does not cross into the standard clearance space of an adjacent outlet.
The Term: "longitudinal length"
Context and Importance: This term is one of the two explicit dimensional limitations that were amended during reissue. The precise start and end points for measuring this "length" on a product with curved or complex surfaces could become a point of contention, directly impacting the infringement analysis.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: A party might argue that "longitudinal length" refers to the main body of the housing, excluding minor protrusions, consistent with the patent's overall goal of a compact body.
- Evidence for a Narrower Interpretation: The claim states the length extends "between the front wall and the rear end" ('794 Patent, col. 13:48-50). A party could argue this requires measurement from the absolute forward-most point of the front face to the absolute rear-most point of the housing, demanding a strict adherence to the overall physical envelope. The narrowing amendment during reissue may support this stricter interpretation.
VI. Other Allegations
- Willful Infringement: The prayer for relief seeks a determination of willful infringement and enhanced damages (Compl. p. 10, ¶C). However, the complaint does not provide sufficient detail for analysis, as it does not plead specific facts concerning when or how Defendants allegedly became aware of the '794 Patent.
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of definitional scope: How will the court construe the functional claim limitation "no interference with an adjacent receptacle"? Will it be interpreted as an absolute standard, or will it be defined by the conventions of a person of ordinary skill in the art regarding typical outlet usage?
- A key evidentiary question will be one of factual verification: The infringement claim rests on precise physical measurements. The case will likely involve a factual dispute over the exact "longitudinal length" and "width" of the accused chargers, with the outcome potentially turning on contested expert testimony regarding measurement methodology.
- A central legal question, arising from the procedural history, will be the impact of claim narrowing during reissue: How will the amendment changing "equal to or less than 2.0 inches" to "less than 2.0 inches" affect the infringement analysis and potential defenses, such as intervening rights, available to the defendants?