Voltstar Tech Inc v. Tozo Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Voltstar Technologies, Inc. (Illinois)
  • Defendant: Tozo Inc (Washington)
  • Plaintiff’s Counsel: Sriplaw, PLLC.
• Case Identification: 2:24-cv-00673, W.D. Wash., 05/15/2024
• Venue Allegations: Venue is based on Defendant being a Washington corporation with its principal place of business within the Western District of Washington.
• Core Dispute: Plaintiff alleges that Defendant’s compact USB wall charger infringes a reissue patent related to the dimensional and functional characteristics of small form-factor power adapters.
• Technical Context: The technology concerns AC-to-DC power adapters for portable electronics, a field where compact size, convenience, and avoidance of obstructing adjacent electrical outlets are significant market drivers.
• Key Procedural History: The patent-in-suit, RE48,794 E, is a reissue of U.S. Patent No. 9,024,581. During the reissue process, asserted Claim 1 was amended to narrow its scope, changing a length limitation 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." The complaint alleges that the reissued claim is substantially identical to the original, which may be relevant to the calculation of damages under 35 U.S.C. § 252.

Case Timeline

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 describes prior art wall chargers as often being bulky, which causes two problems: they can block the use of adjacent electrical outlets, and their length can make them protrude excessively from the wall, making them "unsightly" and susceptible to being struck or dislodged (’794 Patent, col. 1:42-59). The patent also notes that manufacturing methods involving insert molding and manual soldering were complex, time-consuming, and costly (Compl. ¶12; ’794 Patent, col. 2:11-24).
• The Patented Solution: The invention is a compact AC-to-DC charger plug with a housing specifically designed and dimensioned to avoid interfering with adjacent outlets (’794 Patent, col. 1:45-48). The design also focuses on improved manufacturability by using slidably mounted power blades that connect to the internal circuit board via spring contacts, which is presented as an alternative to more complex molding and soldering processes (’794 Patent, Abstract). The complaint includes an image of an exemplary charger to illustrate the patented design (Compl. p. 4).
• Technical Importance: This design approach addresses a persistent consumer demand for smaller, less obtrusive, and more convenient power adapters for the expanding market of portable electronic devices (Compl. ¶12).

Key Claims at a Glance

• The complaint asserts infringement of at least Claim 1 (Compl. ¶27).
• Independent Claim 1 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 to connect to a power source.
  • A DC connector to provide power to a rechargeable device via a power cord.
  • A housing with a specific size: a longitudinal length of less than 2.0 inches and a width of the outer profile less than 1.75 inches.
  • An outer profile that has "no interference with an adjacent receptacle" of the power source.
  • A configuration where the power cord can be conveniently connected and disconnected while the charger remains plugged in, particularly when space is limited.
• The complaint does not explicitly reserve the right to assert dependent claims.

III. The Accused Instrumentality

Product Identification

• The accused product is the "Tozo PD Fast Charger" (Compl. ¶18).

Functionality and Market Context

• The Tozo PD Fast Charger is described as a charger that connects between an AC power source, like a wall outlet, and a device such as a mobile phone to recharge its battery using DC power (Compl. ¶19). The complaint alleges the product's key infringing features are its reduced size and shape, which allows a power cord to be easily inserted and removed and, crucially, prevents the charger from blocking or interfering with adjacent outlets when plugged in (Compl. ¶¶20-21). A photograph in the complaint shows the accused charger plugged into a standard duplex wall outlet, occupying the top receptacle without physically obstructing the bottom one (Compl. p. 6).

IV. Analysis of Infringement Allegations

RE48,794 E Infringement Allegations

Note: The complaint references a claim chart in "Exhibit 2," which was not filed with the complaint. This table is constructed from the narrative allegations in the complaint body.

• Identified Points of Contention:
  • Factual Question: The infringement analysis will turn on factual verification. While the complaint provides specific measurements for the accused product (Compl. ¶24), these figures will be subject to discovery and expert measurement, representing a primary potential point of dispute.
  • Scope Question: The claim requires "no interference with an adjacent receptacle." The provided photograph shows the accused product's housing is physically close to the adjacent outlet (Compl. p. 6). This raises the question of how "interference" will be defined and whether mere proximity, without actual obstruction of a standard plug, meets that limitation.

V. Key Claim Terms for Construction

• The Term: "outer profile"

• Context and Importance: This term is critical because it defines the boundary for both the dimensional limitations (width less than 1.75 inches) and the functional limitation ("no interference"). The case may hinge on what physical parts of the charger constitute the "outer profile" for measurement and interference testing. Practitioners may focus on this term because its definition directly controls the infringement analysis for the patent's core claims.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: A party might argue the term should be given its plain and ordinary meaning, encompassing the maximum dimensions of the main charger housing, excluding the prongs.
  • Evidence for a Narrower Interpretation: The patent states the housing forms "an outer profile defined by a perimeter of the front wall and defined by a plug body extending rearward from the front wall" (’794 Patent, col. 14:36-39). A party could use this language to argue that the "outer profile" is tied specifically to the shape of the front face and the main body, potentially excluding other features.

• The Term: "no interference"

• Context and Importance: This functional limitation is central to the non-obviousness argument and the infringement allegation. The dispute will likely focus on the degree of clearance required to satisfy "no interference."

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The background section states that prior art plugs provide "little or no interference" (’794 Patent, col. 1:47-48). Plaintiff could argue that the claim term "no interference" should be interpreted in this context to mean not preventing the functional use of the adjacent outlet by a standard plug, rather than requiring absolute physical separation under all conditions.
  • Evidence for a Narrower Interpretation: A defendant might argue for a strict interpretation, suggesting that "no interference" means the "outer profile" cannot enter the physical space that any standard or even oversized plug might occupy in the adjacent receptacle. The absolute nature of the term "no" could be contrasted with the specification's more qualified "little or no" to argue the claim demands a stricter standard than the background description.

VI. Other Allegations

• Willful Infringement: The complaint includes a prayer for relief seeking a finding of willful infringement and enhanced damages (Compl., Prayer for Relief ¶C). However, the body of the complaint does not plead specific facts to support a finding of willfulness, such as allegations of pre-suit knowledge of the patent or deliberate copying. The allegations are presently conclusory.

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

• A central issue will be one of factual proof: can Plaintiff establish through expert measurement that the accused Tozo PD Fast Charger's "longitudinal length" and "width of the housing outer profile" fall within the precise numerical limitations recited in the reissued Claim 1?
• The case will also depend on claim construction: how will the court define the scope of the functional term "no interference"? The resolution will determine whether the accused product's design, which sits in close proximity to an adjacent outlet, infringes this key limitation.
• A third question relates to damages under 35 U.S.C. § 252: is reissued Claim 1 "substantially identical" to the original patent's claim, as the plaintiff alleges? The answer will determine whether Voltstar can potentially recover damages for infringement that occurred prior to the reissue date of October 26, 2021.