Voltstar Tech Inc v. Mizco Intl Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Voltstar Technologies, Inc. (Illinois)
  • Defendant: Mizco International Inc. (New York)
  • Plaintiff’s Counsel: Sriplaw PLLC
• Case Identification: 1:23-cv-05482, S.D.N.Y., 06/27/2023
• Venue Allegations: Venue is alleged to be proper as Defendant has committed acts of infringement in the district and is subject to personal jurisdiction.
• Core Dispute: Plaintiff alleges that Defendant’s wall chargers and wireless charging stand infringe three patents related to compact charger design and energy-saving technology that reduces "phantom load."
• Technical Context: The technologies at issue relate to power adapters for consumer electronics, a market where physical size, convenience, and energy efficiency are significant features.
• Key Procedural History: U.S. Patent No. 9,024,581 was reissued as RE48,794 E ('794 Patent), a process which involved amending claim language. U.S. Patent No. 7,910,833 ('833 Patent) has an extensive post-grant history, including a disclaimer of several claims, a re-examination that amended asserted claim 24 by adding key limitations, and an inter partes review (IPR) that resulted in the cancellation of other claims. This history may significantly influence the construction and enforceability of the surviving asserted claims.

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 addresses issues with prior art power adapter plugs that are often bulky. This bulk can cause the plug to block adjacent electrical outlets on a wall or power strip and interfere with furniture placed in front of the outlet (Compl. ¶11; ’794 Patent, col. 1:41-54).
• The Patented Solution: The invention is a charger plug with a reduced size and an improved internal package. The solution involves specific dimensional limitations to ensure it does not interfere with adjacent outlets, and an internal construction using separate, non-insert-molded power blades that are electrically connected to the circuitry via spring contacts, which helps reduce the overall package size (Compl. ¶¶ 11-12; ’794 Patent, col. 2:42-53, col. 3:39-49).
• Technical Importance: This design allows for more convenient and efficient use of crowded power outlets, a common issue for consumers with multiple electronic devices (Compl. ¶11).

Key Claims at a Glance

• The complaint asserts at least Claim 1 (Compl. ¶48).
• The essential elements of independent Claim 1 include:
  • A charger plug for converting 120V input power to DC output power.
  • The plug includes a housing and first and second separate blade members secured within the housing with prong portions extending from a front wall.
  • A DC connector for a power cord.
  • The housing has specific dimensions: a longitudinal length of less than 2.0 inches and a width of the housing outer profile of less than 1.75 inches.
  • The outer profile is configured to have no interference with an adjacent receptacle on a standard wall outlet.
• The complaint does not explicitly reserve the right to assert dependent claims.

U.S. Patent No. 7,910,833 - "Energy-Saving Power Adapter/Charger," issued March 22, 2011

The Invention Explained

• Problem Addressed: The patent addresses the problem of "phantom load" or "vampire load," where power adapters continue to draw residual power from an outlet even when the connected electronic device is fully charged, turned off, or disconnected (Compl. ¶18; ’833 Patent, col. 2:3-8).
• The Patented Solution: The invention is a power adapter or charger with internal switching circuitry that automatically de-powers at least a portion of the device to reduce or eliminate power consumption when the connected electronic device is not drawing power (’833 Patent, Abstract). The charger determines this "off state" by using a "load sensing portion" that monitors the power draw of the connected device (Compl. ¶¶ 42-43; ’833 Patent, col. 10:17-46).
• Technical Importance: This technology reduces wasteful energy consumption, addressing both environmental concerns and consumer electricity costs (Compl. ¶18; ’833 Patent, col. 2:9-13).

Key Claims at a Glance

• The complaint asserts Claims 24, 33, and 36 (Compl. ¶53).
• The essential elements of independent Claim 24 (as amended by re-examination) include:
  • A power device for supplying power to an electronic device.
  • Power circuitry for converting input voltage to output voltage and for determining an "off" state.
  • Switching circuitry to electrically activate the power circuitry to the "on" state.
  • A load sensing portion operable to sense one or more pulses and determine the power or load being drawn from the power device by the electronic device based thereon.
  • The load sensing portion determines the power or load by measuring the frequency of the pulses.
• The complaint asserts dependent claims 33 and 36.

U.S. Patent No. 7,960,648 - "Energy-Saving Cable Assemblies," issued June 14, 2011

• Technology Synopsis: This patent, a continuation of the ’833 Patent, also targets the reduction of phantom load (Compl. ¶22). The invention is a cable assembly that includes a remotely locatable switch, allowing a user to disconnect the device from power draw without unplugging the charger from the wall. The switch can be co-located with the connector that plugs into the electronic device for user convenience (’648 Patent, Abstract).
• Asserted Claims: The complaint asserts Claims 31, 32, and 39 (Compl. ¶¶ 43, 58).
• Accused Features: The "iessentials Wireless Charger" is accused of infringing. The allegations focus on its internal circuitry that automatically shuts off power when a device is fully charged or not present, which is alleged to reduce phantom load (Compl. ¶¶ 43, 45).

III. The Accused Instrumentality

Product Identification

• Accused Product #1: "iessentials USB Car & Wall Charger"
• Accused Product #2: "iessentials 4 Piece Charging Kit" (specifically, the wall charger component)
• Accused Product #3: "iessentials wireless charging stand"
  (Compl. ¶¶ 23, 30, 37).

Functionality and Market Context

• The "iessentials wall charger" and "iessentials charging kit" are alleged to be AC-to-DC power adapters. The complaint alleges their key functionality is their compact size, which prevents them from blocking adjacent outlets (Compl. ¶¶ 25, 32). The complaint provides a photo of the "iessentials wall charger" distributed by the Defendant (Compl. p. 8). The complaint also provides specific measurements for the chargers: the wall charger has a length of approximately 1.077 inches and a width of 1.364 inches, while the charging kit charger has a length of approximately 1.755 inches and a width of 1.403 inches (Compl. ¶¶ 29, 36).
• The "iessentials Wireless Charger" is a Qi-compliant wireless charger for small personal electronics (Compl. ¶¶ 38-39). The complaint alleges its key functionality is its use of "internal monitoring and switch circuitry" to detect when a device is fully charged, and a "novel load sensing portion, which senses the frequency of pulses" to determine the load and control the current flow (Compl. ¶¶ 42-43). The complaint includes a photo of this wireless charging stand (Compl. p. 10).

IV. Analysis of Infringement Allegations

RE48,794 E Infringement Allegations

7,910,833 E Infringement Allegations

The complaint references a claim chart in its Exhibit 6, which was not filed with the complaint. The narrative infringement theory alleges that the "iessentials Wireless Charger" practices the inventions of the ’833 and ’648 Patents (Compl. ¶43). The core allegation is that the wireless charger’s internal circuitry performs the claimed energy-saving function. Specifically, the complaint states the charger uses "internal monitoring and switch circuitry to detect when a mobile electronic device requires charging or is fully charged" and contains a "novel load sensing portion, which senses the frequency of pulses... to determine the load being drawn, and to determine an 'off' state for the device" (Compl. ¶42). This allegation of sensing the frequency of pulses directly maps to language that was added to asserted Claim 24 of the ’833 patent during re-examination.

• Identified Points of Contention:
  • Scope and Construction Question ('794 Patent): While the complaint alleges the accused chargers meet the dimensional limitations, a key question for the court may be whether their internal construction meets the "separate blade members secured within the housing" limitation. This language was intended to distinguish over prior art "insert molded" blades, and the complaint is silent on how Defendant’s products are constructed internally.
  • Technical Question ('833 Patent): The complaint alleges the accused Qi wireless charger infringes by "sens[ing] the frequency of pulses" to determine load (Compl. ¶42). The ’833 patent specification, however, appears to teach this concept in the context of wired transformers (e.g., monitoring pulses from a "transformer secondary winding") (’833 Patent, col. 11:8-12). A central dispute may be whether the accused product’s wireless power transfer mechanism, which relies on electromagnetic induction between coils (Compl. ¶41), performs a function that is technically and legally equivalent to the specific pulse frequency measurement described in the patent and its amended claims.

V. Key Claim Terms for Construction

• Term ('794 Patent, Claim 1): "separate blade members secured within the housing"

  • Context and Importance: This term appears central to distinguishing the claimed invention from prior art that used a costly and less reliable "insert molding" process for power blades (’794 Patent, col. 1:62-67). Practitioners may focus on this term because infringement could turn on whether the accused chargers use a construction method that falls within the scope of "secured," as opposed to being molded-in.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The claim language itself does not specify a particular method of securing the blades, which could support a construction covering any method of attachment other than integral molding.
    • Evidence for a Narrower Interpretation: The specification and figures describe a specific solder-less assembly where blades (12) are slid into slots in the housing and held in electrical contact by spring contacts (16), not by permanent bonding or molding (’794 Patent, FIG. 2B; col. 3:39-49). This could support a narrower construction limited to a non-permanent, mechanical assembly.

• Term ('833 Patent, Claim 24): "a load sensing portion operable to sense one or more pulses and determine the power or load... by measuring the frequency of the pulses"

  • Context and Importance: This language was added to Claim 24 during re-examination, presumably to overcome prior art. The complaint's infringement allegation against the wireless charger hinges on this exact functionality (Compl. ¶42). The definition of this term will therefore be critical to determining infringement.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: A plaintiff may argue the term should be read broadly to cover any system that uses pulse frequency as a proxy for power load, including the handshaking and power management communications in a Qi wireless system.
    • Evidence for a Narrower Interpretation: A defendant may argue the term is limited to the embodiments disclosed in the specification, which describe monitoring pulses from the secondary winding of a physical transformer within a wired AC/DC converter (’833 Patent, Fig. 11; col. 11:8-12). This could create a mismatch with the accused wireless charger, which operates on the principle of electromagnetic induction between two separate devices (Compl. ¶41).

VI. Other Allegations

• Indirect Infringement: The complaint exclusively pleads counts for direct infringement under 35 U.S.C. § 271(a) (Compl. ¶¶ 47, 52, 57).
• Willful Infringement: The complaint's prayer for relief seeks a determination of willful, wanton, and deliberate infringement, which could lead to enhanced damages (Compl. p. 14, ¶C). The complaint does not allege any facts indicating pre-suit knowledge by the Defendant, suggesting the willfulness claim may be based on continued infringement after the filing of the lawsuit.

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

1. A core issue will be one of technical and constructional scope: Can the '833 patent's claims, which were narrowed during post-grant proceedings to cover load-sensing by "measuring the frequency of pulses" from transformer circuitry, be construed to read on the power management protocol of the accused Qi-standard wireless charger, which operates via electromagnetic induction between coils?

2. A key evidentiary question will be one of structural infringement: Beyond meeting the dimensional requirements of the '794 patent, are the accused chargers built with "separate blade members secured within the housing" as claimed, or do they use a different construction, such as the insert-molding technique the patent sought to improve upon?

3. A central legal question will be the impact of prosecution history: How will the extensive and complex post-grant history of the '833 patent—including a disclaimer, re-examination, and IPR—shape the doctrine of equivalents and the interpretation of the surviving asserted claims, particularly the "frequency of pulses" limitation that was critical to the patent's survival and is now the crux of the infringement allegation?