Voltstar Tech Inc v. Motorola Mobility LLC

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Voltstar Technologies Inc. (Illinois)
  • Defendant: Motorola Mobility LLC (Delaware)
  • Plaintiff’s Counsel: Sriplaw PLLC
• Case Identification: 0:23-cv-61959, S.D. Fla., 10/13/2023
• Venue Allegations: Venue is asserted on the basis that Defendant is subject to personal jurisdiction in the district and has allegedly committed acts of infringement there.
• Core Dispute: Plaintiff alleges that Defendant’s wall chargers and wireless charging pads infringe patents related to compact charger design and energy-saving power management technology.
• Technical Context: The technology at issue addresses the market-driven need for smaller, more convenient, and energy-efficient power adapters for ubiquitous portable electronic devices.
• Key Procedural History: The complaint notes that U.S. Patent No. RE48,794 E is a reissue of U.S. Patent No. 9,024,581, with claim language amended to narrow the claimed dimensions of the charger housing. The provided patent documents for the other patents-in-suit, U.S. Patent Nos. 7,910,833 and 7,960,648, indicate they have undergone significant post-grant proceedings, including reexaminations and an Inter Partes Review, resulting in the cancellation and amendment of numerous claims.

Case Timeline

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 describes conventional charger plugs as being bulky, often interfering with the use of adjacent power outlets, and having high manufacturing costs due to complex assembly processes like insert-molding electrical blades and hand-soldering them to internal circuit boards (RE48,794 E Patent, col. 1:41-col. 2:68).
  • The Patented Solution: The invention is a charger with a compact housing achieved through a simplified assembly. It utilizes blades that are slidably mounted into the housing and connect to the internal printed circuit board via solder-less spring contacts, which are biased against the blades to ensure electrical connection (RE48,794 E Patent, Abstract; col. 3:15-24). The complaint includes a photograph of what it presents as an example of such a charger (Compl. ¶11).
  • Technical Importance: This design approach sought to meet market demand for smaller, less obtrusive, and more cost-effective chargers by rethinking the mechanical and electrical interface between the external power prongs and the internal conversion circuitry (RE48,794 E Patent, col. 2:41-47).
• Key Claims at a Glance:
  • The complaint asserts independent Claim 1 (Compl. ¶41).
  • 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 power cord.
    • The housing being sized so that its longitudinal length is "less than 2.0 inches" and the width of its "outer profile" is "less than 1.75 inches."
    • The housing's outer profile having "no interference with an adjacent receptacle of the power source."
  • The complaint is silent on the assertion of any dependent claims.

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

• Patent Identification: 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," where power adapters continue to consume energy from a wall outlet even after the connected electronic device is fully charged or disconnected ('833 Patent, col. 1:62-col. 2:4).
  • The Patented Solution: The invention is a power adapter with internal switching circuitry that automatically cuts off power to most of its own components when it detects that the connected device is no longer drawing a significant load. This load is determined by a "load sensing device" that "senses the pulse width and recognizes how slow or fast the pulse is repeated to determine the load" ('833 Patent, Abstract; col. 9:16-35).
  • Technical Importance: This technology was aimed at reducing electricity waste, a topic of increasing consumer awareness and regulatory scrutiny concerning standby power consumption ('833 Patent, col. 2:5-12).
• Key Claims at a Glance:
  • The complaint asserts independent Claim 24 and dependent Claims 33 and 36 (Compl. ¶46).
  • The essential elements of independent Claim 24 (as amended by reexamination) include:
    • A power device for supplying power to an electronic device.
    • Power circuitry for converting input voltage and determining an "off" state.
    • Switching circuitry to activate the power circuitry to an "on" state.
    • A "load sensing portion" that is operable to sense pulses and determine the power being drawn by "measuring the frequency of the pulses."
  • The complaint also asserts dependent claims, which add further limitations.

Multi-Patent Capsule: U.S. Patent No. 7,960,648 - "Energy Saving Cable Assemblies"

• Patent Identification: U.S. Patent No. 7,960,648, "Energy Saving Cable Assemblies," issued June 14, 2011.
• Technology Synopsis: A continuation of the '833 patent family, this patent focuses on a cable assembly with integrated switching circuitry designed to eliminate phantom load ('648 Patent, Compl. ¶22). The key concept is to use a signal from the electronic device itself (e.g., from a USB port that powers down when the device is off) to control a switch that disconnects the main charger circuitry from the AC power source, thereby stopping power draw ('648 Patent, col. 3:28-40).
• Asserted Claims: The complaint asserts independent Claims 31 and 39 (as amended by reexamination) and dependent Claim 32 (Compl. ¶51).
• Accused Features: The complaint alleges the internal monitoring and switching features of the Motorola Wireless Charger infringe these claims by using pulse frequency sensing to determine when to shut off power (Compl. ¶35-36, 51).

III. The Accused Instrumentality

Product Identification

• The complaint accuses the "Motorola TurboPower 20 USB-C Wall Charger" (the "Motorola Wall Charger") and the "Motorola 15 W TurboPower Wireless Charging Pad" (the "Motorola Wireless Charger") (Compl. ¶23, 30).

Functionality and Market Context

• The Motorola Wall Charger is described as a compact AC-to-DC power adapter that plugs into a wall outlet to charge devices like mobile phones via a USB-C connection (Compl. ¶24). The complaint alleges its small size prevents it from blocking adjacent outlets (Compl. ¶25). The complaint includes a photograph of the accused Motorola Wall Charger. (Compl. p. 6).
• The Motorola Wireless Charger is described as a Qi-compliant pad that provides inductive power to mobile devices (Compl. ¶31, 34). The complaint alleges it contains "internal monitoring circuitry to detect when a mobile electronic device requires charging or is fully charged" and uses "a novel load sensing portion, which senses the frequency of pulses" to determine when to enter an "off" state (Compl. ¶35). The complaint includes a photograph of the accused Motorola Wireless Charger. (Compl. p. 7).
• The complaint alleges these products are used to charge ubiquitous consumer electronics, with the wireless charger operating on the global Qi standard (Compl. ¶24, 32).

IV. Analysis of Infringement Allegations

The complaint states that claim charts are attached as Exhibits 4 and 5, but these exhibits were not filed with the complaint. The infringement theory is therefore summarized below in prose based on the complaint's narrative allegations.

• '794 Patent Infringement Allegations
  The complaint alleges that the Motorola Wall Charger directly infringes at least Claim 1 of the '794 Patent (Compl. ¶41). The infringement theory is based on allegations that the product is a charger plug with the claimed structural components (housing, blades, DC connector) and, critically, that it meets the dimensional limitations added during reissue (Compl. ¶24-26). Specifically, the complaint alleges the charger has a longitudinal length of approximately 1.894 inches (less than the claimed 2.0 inches) and a width of approximately 1.581 inches (less than the claimed 1.75 inches) (Compl. ¶29). It further alleges the product satisfies the functional requirement of not blocking or interfering with adjacent outlets (Compl. ¶25).

• '833 Patent Infringement Allegations
  The complaint alleges that the Motorola Wireless Charger directly infringes at least Claims 24, 33, and 36 of the '833 Patent (Compl. ¶46). The infringement theory centers on the operation of the product's power management system. The complaint alleges the wireless charger contains "internal monitoring and switch circuitry features" that constitute the claimed power and switching circuitry (Compl. ¶35-36). The core of the allegation is that the accused product's "load sensing portion... senses the frequency of pulses rather than sensing the magnitude of a voltage and/or current, to determine the load being drawn, and to determine an 'off' state for the device" (Compl. ¶35). This allegation directly tracks the "measuring the frequency of the pulses" language that was central to the patentability of Claim 24 during post-grant proceedings.

• Identified Points of Contention:

  • Scope Questions: For the '794 Patent, a potential dispute is the construction of "no interference with an adjacent receptacle." The parties may contest whether this requires zero physical overlap with the space of an adjacent outlet or a more practical standard based on the ability to use a standard plug in that outlet.
  • Technical Questions: For the '833 and '648 Patents, the central dispute will likely be factual and technical: what is the actual mechanism by which the accused Motorola Wireless Charger senses load? The complaint's assertion that it operates by "measuring the frequency of pulses" will be a key point for discovery and expert testimony, as Defendant may argue its product uses a different method (e.g., sensing voltage, current, or interpreting data packets as defined by the Qi wireless charging standard).

V. Key Claim Terms for Construction

• '794 Patent, Claim 1

  • The Term: "no interference with an adjacent receptacle"
  • Context and Importance: This functional limitation is central to the '794 patent's contribution of a compact design. Its construction will determine the standard for infringement, as "interference" is not an absolute term. Practitioners may focus on this term because its ambiguity could be outcome-determinative; a narrow reading might excuse a product with minimal protrusion, while a broad one could capture it.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification states a goal is that "the plug itself provides little or no interference with use of an adjacent receptacle" ('794 Patent, col. 1:45-47). The phrase "little or no" suggests a very high, if not absolute, standard.
    • Evidence for a Narrower Interpretation: The specification also states the plug is sized so as "not to impede access to or use of an adjacent outlet" ('794 Patent, col. 4:66-68). This could support an interpretation focused on practical use, meaning infringement only occurs if another standard plug cannot actually be used in the adjacent receptacle. The figures depicting standard NEMA outlets may also be used to ground the term in a real-world context rather than a theoretical one ('794 Patent, Fig. 20).

• '833 Patent, Claim 24

  • The Term: "a load sensing portion operable to... determine the power or load... by measuring the frequency of the pulses"
  • Context and Importance: This language was added during reexamination and is the specific technical mechanism alleged to be used by the accused wireless charger. The infringement case for the '833 patent hinges on whether the accused product's circuitry literally performs this function.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification describes a load sensing device that "senses the pulse width and recognizes how slow or fast the pulse is repeated to determine the load" ('833 Patent, col. 9:32-35). This language directly supports a method based on pulse repetition rate, or frequency.
    • Evidence for a Narrower Interpretation: The specific embodiment described involves monitoring pulses from a "transformer secondary winding" to drive a "Primary Switch" ('833 Patent, col. 11:8-12). A defendant might argue the claim should be limited to this specific type of circuit architecture, and that a different system, such as one operating under the digital communication protocols of the Qi standard, does not "measure the frequency of the pulses" in the manner taught by the patent, even if it communicates via pulses.

VI. Other Allegations

• Willful Infringement: The complaint's prayer for relief requests a finding of willful infringement (Compl. p. 11, ¶C). However, the factual allegations in the body of the complaint do not assert that Defendant had pre-suit knowledge of the patents-in-suit or engaged in conduct rising to the level of egregious infringement.

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

1. A central evidentiary question will be one of technical operation: Does the accused wireless charger's power management system, which operates under the Qi standard, actually determine load by "measuring the frequency of the pulses" as specifically required by the amended claims of the energy-saving patents, or is there a fundamental mismatch in its technical method?
2. A second core issue will be one of factual proof and definition: Can Plaintiff prove that the accused wall charger's physical dimensions fall within the precise numerical limits of the '794 patent's claim, and how will the court construe the functional requirement of "no interference with an adjacent receptacle"?
3. Given the extensive post-grant histories of all three patents, a significant legal question will concern the scope of relief: To what extent will the doctrine of intervening rights limit damages for the reissued '794 patent, and how will the narrowing amendments made to the '833 and '648 patents during reexamination and IPR affect the calculation of past damages?