Voltstar Tech Inc v. Home Depot USA Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Voltstar Technologies, Inc. (Illinois)
  • Defendant: Home Depot U.S.A., Inc. (Georgia)
  • Plaintiff’s Counsel: Sriplaw PLLC
• Case Identification: 9:22-cv-80711, S.D. Fla., 05/10/2022
• Venue Allegations: Venue is alleged to be proper because Defendant Home Depot has committed acts of infringement and maintains a regular and established place of business in the district, where the accused product was purchased.
• Core Dispute: Plaintiff alleges that Defendant’s Ttech Go! 2-Port Wall Charger infringes a reissue patent related to compact electrical charger plugs with specific dimensional and non-interference characteristics.
• Technical Context: The technology concerns the physical design and packaging of AC-to-DC power adapters, aiming to reduce their size to prevent the obstruction of adjacent electrical outlets.
• Key Procedural History: The patent-in-suit, RE48,794, is a reissue of U.S. Patent No. 9,024,581. The complaint notes that during reissue, Claim 1 was amended to narrow its scope, changing the longitudinal length requirement from "equal to or less than 2.0 inches" to "less than 2.0 inches" and adding a new width limitation of "less than 1.75 inches." This amendment may focus the infringement analysis on these specific dimensions.

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
2022-05-10	Complaint Filed

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

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 identifies issues with prior art electrical charger plugs, noting they are often bulky. This bulk can cause the plug to block adjacent receptacles on a wall outlet or power strip and protrude excessively, making it "unsightly" or susceptible to being dislodged (RE48,794 E Patent, col. 1:42-59). The patent also describes prior manufacturing methods involving insert molding of blades and manual soldering as expensive, time-consuming, and error-prone (RE48,794 E Patent, col. 1:60-col. 2:32).
• The Patented Solution: The invention is a power-converting charger plug with a reduced physical profile. A photograph included in the complaint shows an example of the patented charger plug (Compl. p. 4). The design, as detailed in the specification, achieves its compact size and improved manufacturability through a specific housing construction and the use of blades that are slidably mounted into the housing and connected to the internal circuit board via solder-less spring contacts, rather than being insert-molded and soldered (RE48,794 E Patent, Abstract; col. 3:14-27). This configuration is intended to produce a charger that is small enough not to interfere with the use of neighboring outlets (RE48,794 E Patent, col. 13:46-54).
• Technical Importance: The described technical approach addresses the market demand for smaller, more convenient, and less obtrusive power adapters, a key consideration for the growing market of portable electronic devices (RE48,794 E Patent, col. 1:12-18).

Key Claims at a Glance

• The complaint asserts infringement of at least Claim 1 of the ’794 Patent (Compl. ¶23).
• 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 that extend from a front wall.
  • A DC connector with an aperture to receive a power cord plug end.
  • A housing that forms a charger plug face area and an outer profile.
  • The housing being sized so its longitudinal length is "less than 2.0 inches" and "a width of the housing outer profile being less than 1.75 inches."
  • The outer profile having "no interference with an adjacent receptacle" when a "like charger plug" is mounted in any other available orientation.
  • The configuration allowing the power cord to be conveniently connected and disconnected while the charger remains plugged into the receptacle.

III. The Accused Instrumentality

Product Identification

Ttech Go! 2-Port Wall Charger (Compl. ¶14).

Functionality and Market Context

The complaint describes the accused product as a wall charger used to connect an AC power source to a device, such as a mobile phone, to provide DC charging power (Compl. ¶15). The complaint alleges the product employs a "reduced plug-size" design which, upon being plugged into a wall outlet, "does not block or interfere with the use of adjacent outlets" (Compl. ¶16). It is also alleged that the size and shape allow a power cord to be easily inserted and removed while the charger is plugged in (Compl. ¶17). The complaint provides a photograph showing the front face and prongs of the accused white "Ttech Go! 2-Port Wall Charger" (Compl. p. 5).

IV. Analysis of Infringement Allegations

The complaint references a claim chart in an "Exhibit 2" that purports to show how the accused product meets each element of Claim 1; however, this exhibit was not attached to the publicly filed complaint (Compl. ¶18, 23). The narrative allegations in the complaint form the basis of the infringement theory.

The plaintiff alleges that the Ttech Go! 2-Port Wall Charger directly infringes at least Claim 1 of the ’794 Patent. The core of this allegation rests on the physical form factor and dimensions of the accused product. The complaint asserts that the charger is designed to be connected between an AC outlet and a DC-powered device, meeting the preamble of the claim (Compl. ¶15). The infringement allegation centers on the product's specific dimensions, with the complaint explicitly stating that the charger has a longitudinal length of "approximately 1.228 inches" (which is less than the claimed 2.0 inches) and a width of "approximately 1.300 inches" (which is less than the claimed 1.75 inches) (Compl. ¶20). Further, the complaint alleges the product meets the functional limitation of not interfering with adjacent outlets (Compl. ¶16).

Identified Points of Contention

• Scope Questions: A central dispute may arise over the proper methodology for measuring the "longitudinal length" and the "width of the housing outer profile" as recited in Claim 1. The definition of "housing outer profile" could be contested—for instance, whether it represents the maximum dimension of the main body at any point or an average profile, and whether it includes or excludes minor protrusions.
• Technical Questions: The complaint's infringement theory focuses on the external dimensions and non-interference properties of the accused charger. It does not provide detail on the product's internal construction (e.g., how the prongs connect to the circuit board). A key evidentiary question for the plaintiff will be to demonstrate that the accused product meets all limitations of Claim 1, including any structural elements that are not visible externally. The complaint also makes a factual assertion about the product causing "no interference," which is a testable condition that may become a point of factual dispute.

V. Key Claim Terms for Construction

The Term: "a width of the housing outer profile"

• Context and Importance: This limitation was added during the reissue process that resulted in the ’794 Patent, suggesting it was key to overcoming a rejection or otherwise distinguishing the prior art (Compl. ¶12, fn. 1). Its construction will be critical, as the infringement allegation relies on a specific measurement of the accused product's width (Compl. ¶20). Practitioners may focus on this term because its definition directly impacts whether the accused product's measured width of "approximately 1.300 inches" falls within the claim.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The specification repeatedly emphasizes the goal of reducing the overall "package size" and "profile of the plug," which might support an interpretation of "outer profile" as the main, substantial body of the housing, potentially excluding minor features (RE48,794 E Patent, col. 1:45-46).
  • Evidence for a Narrower Interpretation: The patent figures, such as the front elevation view in Figure 15, depict a specific housing shape with a defined overall width (150). A party could argue that "width of the housing outer profile" must mean the maximum lateral dimension at any point along the housing, consistent with the specific embodiments shown (RE48,794 E Patent, Fig. 15).

The Term: "no interference with an adjacent receptacle"

• Context and Importance: This is a functional limitation that defines a required performance characteristic of the claimed charger. The meaning of "interference" is not explicitly defined, and its interpretation will determine the standard for infringement.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The background section frames the problem as plugs that provide "little or no interference with use of an adjacent receptacle" (RE48,794 E Patent, col. 1:47-49). This general language could support a broad reading where any physical obstruction that prevents a standard plug from being fully seated constitutes "interference."
  • Evidence for a Narrower Interpretation: Claim 1 specifies that the "no interference" condition must be met when "a like charger plug is mounted in all available orientations in any of the other receptacles" (RE48,794 E Patent, col. 13:49-54). A party could argue this sets up a very specific, and potentially demanding, test condition. The determination of what constitutes a "like charger plug" and "all available orientations" in standard outlets (e.g., duplex, quadplex, power strips) may require extrinsic evidence and could support a narrower definition of what legally constitutes "interference."

VI. Other Allegations

• Indirect Infringement: The complaint alleges induced infringement under 35 U.S.C. § 271(b), stating that Home Depot requested, encouraged, and instructed customers to use the accused chargers in an infringing manner through activities such as advertising, promotion, and the distribution of guidelines (Compl. ¶¶28, 31).
• Willful Infringement: The complaint does not contain a specific count for willful infringement or plead facts establishing pre-suit knowledge of the patent. However, the prayer for relief requests a determination that Defendant's infringement has been "willful, wanton, and deliberate" and seeks enhanced damages (Compl. Prayer for Relief ¶C).

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

1. A core issue will be one of dimensional compliance: Will objective, expert measurement of the "Ttech Go! 2-Port Wall Charger" confirm that its dimensions fall within the specific numerical limits of Claim 1, and what construction of the term "housing outer profile" will the court adopt to guide that measurement?

2. A second central question will be one of functional performance: How will the functional limitation of "no interference with an adjacent receptacle" be tested and proven? The case may turn on the evidence presented to show whether the accused product meets this condition under the claim's specific scenario of a "like charger plug" being used in "all available orientations."

3. Finally, an evidentiary question will be one of completeness: While the complaint focuses on the external dimensions of the accused product, the plaintiff will bear the burden of proving infringement of all claim elements, including any internal structural features required by the patent but not addressed in the initial pleading.