DCT

1:24-cv-03242

Voltstar Tech Inc v. Salom America Co

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:24-cv-03242, N.D. Ill., 04/23/2024
  • Venue Allegations: Venue is alleged to be proper as Defendant has committed acts of infringement in the district and is subject to personal jurisdiction there.
  • Core Dispute: Plaintiff alleges that Defendant’s USB-C wall chargers and wireless charging pads infringe three patents related to compact charger design and energy-saving technologies that reduce phantom power load.
  • Technical Context: The technology concerns power adapters for consumer electronics, a highly competitive market where compact size, energy efficiency, and convenience are significant drivers of consumer choice.
  • Key Procedural History: The asserted patents have significant post-grant histories. U.S. Patent RE48,794 is a reissue of U.S. Patent 9,024,581, with the reissue proceeding narrowing a key dimensional limitation. U.S. Patent 7,910,833 underwent both an inter partes reexamination and an inter partes review (IPR), resulting in the cancellation and amendment of multiple claims. Similarly, U.S. Patent 7,960,648 also had claims cancelled via an IPR. This extensive history will be central to claim construction and validity analyses.

Case Timeline

Date Event
2008-05-21 Priority Date for U.S. Patent No. 9,024,581 (reissued as RE48,794 E)
2008-05-27 Priority Date for U.S. Patent Nos. 7,910,833 and 7,960,648
2009-11-26 Application for the '581 Patent published
2011-03-22 U.S. Patent No. 7,910,833 issued
2011-06-14 U.S. Patent No. 7,960,648 issued
2015-05-05 U.S. Patent No. 9,024,581 issued
2016-10-12 Inter Partes Review (IPR2017-00067) filed against '833 Patent
2017-11-03 Inter Partes Reexamination Certificate issued for '833 Patent
2021-10-26 Reissue Patent RE48,794 E issued
2022-01-21 Inter Partes Review Certificate issued for '833 Patent
2024-04-23 Complaint Filed

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

U.S. Reissue Patent No. RE48,794 E - "Charger Plug With Improved Package," issued Oct. 26, 2021

The Invention Explained

  • Problem Addressed: The patent describes issues with prior art charger plugs, noting they are often bulky, which interferes with the use of adjacent electrical outlets. It also identifies the high cost and complexity of manufacturing processes like insert-molding blades and hand-soldering connections (RE48,794 Patent, col. 1:41-50, 2:12-24).
  • The Patented Solution: The invention claims a charger plug with specific, compact dimensional limits for its housing. It discloses a novel assembly method using slidable blades and internal spring contacts that create a solder-less connection to the printed circuit board, which aims to reduce the overall package size and simplify manufacturing (RE48,794 Patent, Abstract; col. 3:13-28). The complaint provides a photograph of a charger embodying these design principles (Compl. p. 4).
  • Technical Importance: This design sought to create smaller, more convenient power adapters that do not obstruct adjacent outlets, addressing a common consumer frustration in the market for mobile device accessories (RE48,794 Patent, col. 1:41-50).

Key Claims at a Glance

  • The complaint asserts infringement of independent Claim 1 (Compl. ¶45).
  • The essential elements of Claim 1 include:
    • A charger plug with a housing and separate blade members secured within.
    • 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 a power source.
    • A configuration where the power cord can be conveniently removed while the charger remains plugged in, even in limited space.

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

The Invention Explained

  • Problem Addressed: The patent addresses the problem of "phantom load," where power adapters continue to draw residual power from an outlet even when the electronic device they are meant to charge is disconnected or fully charged, leading to wasted energy ('833 Patent, col. 1:62-2:4).
  • The Patented Solution: The invention describes a power device with internal circuitry that automatically cuts power or enters a no-power "off" state when it determines the connected device no longer needs power. A key component is a "load sensing portion" that can monitor the power draw to make this determination ('833 Patent, Abstract; col. 9:15-24).
  • Technical Importance: This technology was developed to address growing public and regulatory concern over energy waste from phantom loads, in line with broader energy efficiency movements like the "Energy Star" program ('833 Patent, col. 2:5-25).

Key Claims at a Glance

  • The complaint asserts infringement of Claims 24 and 33 (Compl. ¶51). Claim 36 is also asserted but is dependent on claim 33.
  • The essential elements of independent Claim 24 (as amended by inter partes reexamination) include:
    • A power device with power circuitry for converting voltage and determining an "off" state.
    • Switching circuitry to activate the power circuitry to an "on" state.
    • A "load sensing portion" that senses one or more pulses to determine the power load.
    • The load determination is made by "measuring the frequency of the pulses."
  • Independent Claim 33 further specifies that the load sensing portion measures the pulse frequency from transformer control circuitry.

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

  • Technology Synopsis: As a continuation in the '833 patent's family, this patent also targets phantom load. It describes a cable assembly with integrated switch circuitry that can detect when a connected device, such as a laptop, is turned on or off (e.g., by sensing a signal from a USB port). Based on this signal, the assembly automatically connects or disconnects the main power flowing to the charger, thereby eliminating phantom draw when the device is off or disconnected ('648 Patent, Abstract; col. 2:19-25).
  • Asserted Claims: Claims 31, 32, and 39 are asserted (Compl. ¶56). Following inter partes review, which cancelled the original independent claims they depended upon, these claims were amended and now function as independent claims.
  • Accused Features: The complaint alleges that the "internal monitoring and switch circuitry" of the Motorola Wireless Charger infringes these claims, pointing specifically to its alleged use of pulse frequency sensing to determine an "off" state (Compl. ¶39-40).

III. The Accused Instrumentality

Product Identification

  • The complaint identifies two accused instrumentalities: the "Motorola TurboPower 20 USB-C Wall Charger" ("Motorola Wall Charger") and the "Motorola 15 W TurboPower Wireless Charging Pad" ("Motorola Wireless Charger") (Compl. ¶27, ¶34).

Functionality and Market Context

  • The Motorola Wall Charger is described as a reduced-size charger plug designed not to block or interfere with adjacent wall outlets (Compl. ¶29). A photograph of this product is included in the complaint (Compl. p. 7).
  • The Motorola Wireless Charger is a Qi-compliant wireless charging pad that uses electromagnetic induction to charge devices (Compl. ¶35, ¶38). The complaint alleges it contains "internal monitoring circuitry to detect when a mobile electronic device requires charging or is fully charged" and "internal switches... that control the flow of current" (Compl. ¶39). The complaint further alleges this product uses a "novel load sensing portion, which senses the frequency of pulses" to determine when to enter an "off" state (Compl. ¶39). A photograph of the wireless charger is also provided (Compl. p. 8).

IV. Analysis of Infringement Allegations

The complaint references claim chart exhibits that were not provided. The narrative infringement theories are summarized below.

RE48,794 E Infringement Allegations (Prose Summary)

The complaint alleges that the Motorola Wall Charger directly infringes at least Claim 1 of the '794 patent (Compl. ¶45). The theory of infringement is based on the physical dimensions and design of the accused charger. The complaint specifically 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. ¶33). It further alleges that the charger's compact form factor prevents it from blocking adjacent outlets, mapping to the functional limitations of the claim (Compl. ¶29).

7,910,833 Infringement Allegations (Prose Summary)

The complaint alleges that the Motorola Wireless Charger directly infringes at least Claims 24 and 33 of the '833 patent (Compl. ¶51). The infringement theory focuses on the device's internal power management logic. The complaint asserts that the wireless charger’s circuitry performs the functions of the claimed "load sensing portion" by detecting when a device is fully charged and controlling current flow accordingly (Compl. ¶39-40). Critically, the complaint alleges that this circuitry determines the power load by "sens[ing] the frequency of pulses," which directly corresponds to the specific language added to Claim 24 during post-grant proceedings (Compl. ¶39).

Identified Points of Contention

  • Scope Questions: For the '794 patent, a central question will be whether the terms "longitudinal length" and "width of the housing outer profile" are met by the accused product. The dispute may focus on the proper methodology for measuring these dimensions as contemplated by the patent.
  • Technical Questions: For the '833 and '648 patents, a key technical question is whether the accused Motorola Wireless Charger's circuitry actually operates by "measuring the frequency of the pulses" to determine its power state. The complaint makes this assertion, but the case will likely depend on technical evidence from reverse engineering or internal documentation to substantiate this specific mechanism of operation.

V. Key Claim Terms for Construction

Term 1: "longitudinal length... less than 2.0 inches, a width... less than 1.75 inches" ('794 Patent, Claim 1)

  • Context and Importance: These dimensional limitations are the core of the asserted claim, added during reissue to distinguish the invention. Infringement hinges entirely on whether the accused product's physical measurements fall within these precise boundaries.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The patent does not provide an explicit textual definition for these terms, which might support an argument for applying their plain and ordinary meaning.
    • Evidence for a Narrower Interpretation: The prosecution history of the reissue will be critical. The act of adding the width limitation and changing "equal to or less than" to simply "less than" for the length suggests these specific numerical values were added to secure patentability and should be strictly construed (Compl. ¶13, fn. 1). Figures in the patent, such as the dimensional indicators "152" and "160" in Fig. 10, may be used to argue for a specific, non-obvious way of measuring the "profile."

Term 2: "a load sensing portion operable to... determine the power or load... by measuring the frequency of the pulses" ('833 Patent, Claim 24)

  • Context and Importance: This language was added to the claim during post-grant proceedings, presumably to overcome prior art that determined load by other means (e.g., sensing voltage or current magnitude). Practitioners may focus on this term because proving that the accused Qi-standard charger uses this specific "frequency" method, rather than another load-sensing technique, will be essential for the plaintiff's infringement case.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification discusses that power draw can be measured "by the size and frequency of the pulses," potentially allowing for interpretations that do not rely exclusively on frequency ('833 Patent, col. 9:25-27).
    • Evidence for a Narrower Interpretation: The amended claim language explicitly recites "by measuring the frequency of the pulses," which is highly specific. The specification reinforces this by describing that the device "senses the pulse width and recognizes how slow or fast the pulse is repeated to determine the load," directly tying load determination to pulse repetition rate, or frequency ('833 Patent, col. 9:32-35). This language strongly supports a construction limited to frequency-based measurement, excluding methods based solely on pulse width or amplitude.

VI. Other Allegations

  • Willful Infringement: While the complaint does not allege facts to support pre-suit knowledge, the prayer for relief requests a determination that Defendant's infringement was "willful, wanton, and deliberate" and asks for treble damages under 35 U.S.C. § 284 (Compl. p. 12, ¶C).

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

  1. A question of post-grant claim scope: Given the extensive cancellation and amendment of claims in the '833 and '648 patents during reexamination and IPR, a central issue will be the proper construction of the surviving, narrowed claims. Can the limitation requiring load-sensing "by measuring the frequency of the pulses," which was added to secure patentability, be interpreted to read on the accused Qi-standard wireless charging technology?
  2. An evidentiary question of technical operation: Does the accused Motorola Wireless Charger, in fact, determine its power state by measuring pulse frequency, as alleged in the complaint and required by the asserted claims of the '833 and '648 patents? This dispute will likely turn on detailed technical evidence obtained through discovery and reverse engineering of the accused product's chipset and firmware.
  3. A factual question of physical dimension: For the '794 patent, will the accused Motorola Wall Charger be found to meet the precise dimensional limitations of "less than 2.0 inches" in length and "less than 1.75 inches" in width? This will be a factual dispute contingent on the court's adopted measurement methodology and expert testimony.