DCT

2:23-cv-01003

Voltstar Tech Inc v. Fantasia Trading LLC

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:23-cv-01003, W.D. Wash., 07/06/2023
  • Venue Allegations: Venue is alleged to be proper based on Defendants having committed acts of infringement and maintaining a regular and established place of business in the district.
  • Core Dispute: Plaintiff alleges that Defendant’s compact wall chargers and wireless charging stand infringe three patents related to the physical design of charger plugs and energy-saving power-off features.
  • Technical Context: The technology concerns compact AC/DC power adapters for consumer electronics, focusing on physical form factors to avoid blocking adjacent outlets, and on internal circuitry to reduce "phantom" power draw when a device is fully charged or disconnected.
  • Key Procedural History: The asserted patents have a significant post-issuance history. U.S. Patent 9,024,581 was reissued as RE48,794 E, amending claim limitations related to the charger's dimensions. Both U.S. Patents 7,910,833 and 7,960,648 have undergone inter partes reexamination and/or inter partes review, resulting in the cancellation of numerous claims and the amendment of the asserted claims. This history will likely be central to claim construction and may give rise to prosecution history estoppel arguments.

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 No. 7,910,833
2008-05-27 Priority Date for U.S. Patent No. 7,960,648
2011-03-22 Issue Date for U.S. Patent No. 7,910,833
2011-06-14 Issue Date for U.S. Patent No. 7,960,648
2015-05-05 Issue Date for U.S. Patent No. 9,024,581
2021-10-26 Issue Date for Reissue Patent No. RE48,794 E
2023-07-06 Complaint Filing Date

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 charger plugs as often being bulky, leading to several issues: they can block adjacent electrical outlets, protrude excessively from the wall making them unsightly or susceptible to being struck, and have a high manufacturing cost due to complex assembly involving insert-molded blades and soldered wires (’581 Patent, col. 1:35-50, col. 2:6-12).
  • The Patented Solution: The invention proposes a compact charger with a simplified, solder-less construction. It uses separate, non-molded blades that slide into the housing and are held in electrical contact by biased spring contacts connected to the printed circuit board (PCB) (’581 Patent, Abstract; ’581 Patent, col. 3:48-55). This design purports to reduce the overall package size, cost, and assembly time.
  • Technical Importance: The design aims to create a charger plug that is small enough not to interfere with adjacent outlets, a significant usability improvement for consumers dealing with crowded power strips or wall outlets (’581 Patent, col. 1:35-42).

Key Claims at a Glance

  • The complaint asserts independent claim 1 (’794 Patent, col. 13:17-col. 14:2).
  • Essential elements of claim 1 include:
    • A charger plug for converting 120V input to DC output.
    • A housing with a front wall, an outer profile, and a rear end.
    • Separate blade members with prong portions extending from the housing.
    • A DC connector to receive a power cord plug.
    • A specific sizing limitation: a longitudinal length of less than 2.0 inches and a width of the housing outer profile being less than 1.75 inches.
    • A functional limitation: the outer profile having "no interference with an adjacent receptacle of the power source" when mounted.
  • The complaint does not explicitly reserve the right to assert dependent claims for this patent.

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," which is the residual power consumed by power adapters when the connected electronic device is fully charged, turned off, or disconnected (’833 Patent, col. 2:1-4). This continuous power draw wastes energy.
  • The Patented Solution: The invention is a power device with internal circuitry that automatically cuts power to reduce or eliminate phantom load. The circuitry includes a "load sensing portion" that can determine when the device is no longer drawing significant power and, in response, open a switch to disconnect the AC input power (’833 Patent, Abstract; ’833 Patent, col. 9:16-35). One embodiment describes sensing pulses from a transformer to determine the load (’833 Patent, col. 10:25-35).
  • Technical Importance: The technology provides an automated solution to reduce energy waste from the millions of chargers left plugged in, addressing a topic of growing environmental and economic concern at the time of the invention (’833 Patent, col. 2:5-11).

Key Claims at a Glance

  • The complaint asserts claims 24, 33, and 36, which survived reexamination in amended form (’833 Patent C1 Certificate; Compl. ¶76).
  • Essential elements of independent claim 24 (as amended) include:
    • A power device with a first portion for receiving input power and a second portion for delivering output power.
    • Power circuitry for converting the power.
    • Switching circuitry to activate the power circuitry to an "on" state.
    • A "load sensing portion" operable to sense one or more pulses and determine the load being drawn by the electronic device.
    • The load determination is made specifically by "measuring the frequency of the pulses."
  • The complaint also asserts dependent claims 33 and 36 (Compl. ¶76).

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

  • Technology Synopsis: As a continuation-in-part of the '833 patent, this invention describes a cable assembly with integrated switch circuitry (’648 Patent, Abstract). The circuitry can detect a signal from the host device (e.g., a laptop's powered USB port) to determine its "on" or "off" state and accordingly connect or disconnect power from the AC outlet, thereby reducing phantom load (’648 Patent, col. 1:19-25). The asserted claims specifically relate to using pulse frequency from a transformer to monitor load and control the power state (’648 Patent C1 Certificate, claim 31).
  • Asserted Claims: Claims 31, 32, and 39, as amended by reexamination (Compl. ¶81). Independent claim 31 is asserted.
  • Accused Features: The complaint alleges that the Anker Wireless Charger's internal circuitry, which monitors and controls power flow based on the connected device's charging status, infringes these claims (Compl. ¶¶ 65-66, 68).

III. The Accused Instrumentality

Product Identification

  • The complaint names two categories of accused products: a series of compact wall chargers and a wireless charging stand (Compl. ¶¶ 25, 32, 39, 46, 53, 60).

Functionality and Market Context

  • Compact Chargers: This group includes the Anker Powerport III 20 W Cube, Powerport III Nano, Nano II Pro, 521 Charger, and 511 Charger. The complaint alleges these are small, reduced-size AC-to-DC chargers that plug directly into a wall outlet (Compl. ¶¶ 26-27). A central allegation is that their compact form factor prevents them from blocking or interfering with the use of adjacent outlets (Compl. ¶27). The complaint provides a photo of the Anker Powerport III 20 W Cube plugged into a standard duplex outlet, occupying only the bottom socket. (Visual Evidence: Photo of Anker Powerport III 20 W Cube in outlet, Compl. p. 7).
  • Wireless Charger: This product is the Anker PowerWave Stand. It is described as a Qi-compliant wireless charger that connects to an AC power source and provides inductive power to a mobile device (Compl. ¶¶ 61-64). The complaint alleges it contains "internal monitoring and switch circuitry" to detect when a device is fully charged and subsequently control the power flow (Compl. ¶65). Specifically, the complaint alleges it uses a "novel load sensing portion, which senses the frequency of pulses" to determine the load and enter an "off" state (Compl. ¶65).

IV. Analysis of Infringement Allegations

RE48,794 E Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A charger plug capable of connecting with a two or three receptacle power source to convert 120V input power... to DC output power... The accused products are chargers that connect to an AC power source like a wall outlet and provide DC power to a mobile device. (Visual Evidence: Photo of Anker Powerport III Nano in outlet, Compl. p. 8). ¶26, ¶33 col. 1:10-24
being sized so that the charger plug housing comprises a longitudinal length extending between the front wall and the rear end and the longitudinal length is less than 2.0 inches, a width of the housing outer profile being less than 1.75 inches... The complaint provides specific, measured dimensions for the accused chargers, alleging they fall within the claimed limits (e.g., the 20 W Cube is alleged to have a length of approx. 1.322 inches and a width of approx. 1.276 inches). ¶31, ¶38 col. 13:46-51
the outer profile having no interference with an adjacent receptacle of the power source located on all sides of the first receptacle when a like charger plug is mounted in all available orientations in any of the other receptacles... The complaint alleges that when the accused chargers are plugged into a wall outlet, they do not block or interfere with the use of adjacent outlets. (Visual Evidence: Photo of Anker Nano II Pro in outlet, Compl. p. 10). ¶27, ¶34 col. 1:35-42
the charger plug including a DC connector having an aperture adapted to removably receive a corresponding power cord plug end... The accused chargers have a port (e.g., USB-C) for a power cord, and the complaint alleges the cord can be easily inserted and removed while the charger is plugged in. ¶28, ¶35 col. 7:34-39

7,910,833 Infringement Allegations

Claim Element (from Independent Claim 24, as amended) Alleged Infringing Functionality Complaint Citation Patent Citation
a power device for supplying power to an electronic device... The Anker Wireless Charger is a power device that supplies power to electronic devices like smartphones. (Visual Evidence: Photo of Anker PowerWave Stand, Compl. p. 14). ¶61 col. 6:30-34
power circuitry for converting the input power voltage to the output power voltage and for determining an "off" state of the power device... The complaint alleges the Anker Wireless Charger utilizes internal circuitry to control current flow based on the charge-status of the mobile device and to determine an "off" state for the charger. ¶65 col. 10:25-35
a load sensing portion operable to sense one or more pulses and determine the power or load being drawn... by measuring the frequency of the pulses. The complaint alleges the accused wireless charger uses a "novel load sensing portion, which senses the frequency of pulses rather than sensing the magnitude of a voltage and/or current, to determine the load being drawn." ¶65 col. 9:36-39

Identified Points of Contention

  • Scope Questions: For the ’794 patent, a central question will be the construction of "no interference with an adjacent receptacle." This may require the court to define what level of physical or functional obstruction constitutes "interference." For the ’833 and ’648 patents, the scope of "measuring the frequency of the pulses" will be critical, particularly how it is distinguished from other load-sensing techniques.
  • Technical Questions: The infringement case for the ’833 and ’648 patents hinges on a specific technical allegation: that the Anker wireless charger determines load by measuring pulse frequency. A key factual question will be what evidence exists that the accused product actually operates in this manner, as opposed to more common methods like monitoring voltage or current levels.

V. Key Claim Terms for Construction

For U.S. Reissue Patent No. RE48,794 E

  • The Term: "outer profile"
  • Context and Importance: This term is critical because Claim 1 defines infringement based on specific dimensions (width less than 1.75 inches) of the "outer profile." The definition will determine the precise points of measurement on the accused products. Practitioners may focus on this term because its ambiguity could be outcome-determinative for the infringement analysis.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The patent uses the term without a specific definition, which may suggest it should be given its plain and ordinary meaning, potentially encompassing the maximum dimensions of the housing body. The claim recites "an outer profile defined by a perimeter of the front wall and defined by a plug body extending rearward" (’794 Patent, col. 13:62-65), which could be argued to cover the entire exterior surface.
    • Evidence for a Narrower Interpretation: A defendant may argue the term should be limited by the embodiments shown in the figures, potentially excluding certain curves or features from the measurement. The patent repeatedly emphasizes the goal of avoiding interference with adjacent outlets, suggesting the "profile" should be construed in the context of how the device sits in a standard NEMA outlet (’581 Patent, col. 1:35-42).

For U.S. Patent No. 7,910,833

  • The Term: "a load sensing portion operable to sense one or more pulses and determine the power or load being drawn... by measuring the frequency of the pulses"
  • Context and Importance: This term, added during reexamination, defines the specific technical mechanism for achieving the invention's energy-saving function. The entire infringement allegation for the wireless charger rests on whether its circuitry performs this exact function. Practitioners may focus on this term because it appears to be a narrow technical limitation that Plaintiff must prove is met exactly.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The claim language itself is the primary source. A plaintiff might argue it covers any circuit that uses pulse frequency as the input for determining load, regardless of the specific implementation.
    • Evidence for a Narrower Interpretation: The specification describes this concept in the context of monitoring pulses from a "transformer secondary winding SW to drive a Primary Switch" (’833 Patent, col. 11:10-13) or a pulse-width modulation (PWM) switch (’833 Patent, col. 9:40-54). A defendant may argue the claim should be limited to these specific types of pulse-sensing circuits described in the specification, especially given the extensive prosecution history.

VI. Other Allegations

  • Willful Infringement: The complaint makes a request for a finding of willful infringement and enhanced damages in its prayer for relief (Compl. p. 18, ¶C). However, the factual allegations in the body of the complaint do not assert pre-suit knowledge, copying, or other specific facts that would typically be used to substantiate such a claim.

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

  • A key evidentiary question will be one of technical operation: Does the accused Anker wireless charger’s load-sensing circuitry function by "measuring the frequency of pulses" as required by the amended claims of the ’833 and ’648 patents, or does it utilize a different, non-infringing technical method to detect when a device is fully charged?
  • A second core issue will be one of factual compliance: For the ’794 patent, do the physical dimensions of the accused compact chargers, when measured according to a proper construction of the term "outer profile," fall within the specific length and width limitations of the claims?
  • Finally, a central legal question will concern prosecution history: How will the extensive history of reexamination and inter partes review for the ’833 and ’648 patents, which led to the cancellation and amendment of numerous claims, affect the court's construction of the surviving asserted claims and the potential application of prosecution history estoppel to limit their scope?