Voltstar Tech Inc v. Zagg Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Voltstar Technologies, Inc. (Illinois)
  • Defendant: Zagg Inc. (Delaware/Utah) and Mophie Inc. (California/Utah)
  • Plaintiff’s Counsel: Sriplaw PLLC
• Case Identification: 8:23-cv-01348, M.D. Fla., 06/15/2023
• Venue Allegations: Venue is alleged to be proper in the Middle District of Florida because Defendant Zagg Inc. has a regular and established place of business in the district via a retail store.
• Core Dispute: Plaintiff alleges that Defendants’ Mophie-branded wall chargers and wireless charging bases infringe three patents related to compact charger package design and energy-saving technologies that reduce "phantom load."
• Technical Context: The dispute is in the field of consumer power accessories, where compact size, manufacturing cost, and energy efficiency are significant market drivers.
• Key Procedural History: The complaint notes that U.S. Patent RE48,794 is a reissue of U.S. Patent No. 9,024,581, which involved amending claim language to add specific dimensional limitations. The complaint also states that U.S. Patent No. 7,960,648 is a continuation of U.S. Patent No. 7,910,833.

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 conventional AC charger plugs as often being bulky, which can block adjacent wall outlets, and expensive to manufacture due to processes like insert-molding and hand-soldering of electrical blades to internal circuit boards (’794 Patent, col. 1:41-col. 2:67).
• The Patented Solution: The invention is a charger with a reduced physical size achieved by an improved internal package design. Instead of molding the electrical blades into the housing, the blades are separate components that are slidably mounted into the housing and make electrical contact with the internal circuit board via spring contacts (’794 Patent, Abstract; col. 3:13-25). This construction method purportedly obviates the need for insert molding and soldering, allowing for a more compact and less costly final product (’794 Patent, col. 2:45-49).
• Technical Importance: This design approach addresses the market need for smaller, more portable consumer electronics chargers that do not obstruct other outlets and can be manufactured more efficiently and reliably (’794 Patent, col. 2:50-67).

Key Claims at a Glance

• The complaint asserts independent Claim 1 (Compl. ¶57).
• Essential elements of Claim 1 include:
  • A charger plug with a housing and first and second separate blade members.
  • A DC connector for transmitting power to a rechargeable device.
  • The housing being sized with a longitudinal length less than 2.0 inches and a width of the housing outer profile being less than 1.75 inches.
  • The outer profile having no interference with an adjacent receptacle.
• 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," where power adapters continue to draw residual power from a wall outlet even when the electronic device they are meant to charge is fully charged or disconnected, leading to wasted energy (’833 Patent, col. 1:63-col. 2:4).
• The Patented Solution: The invention describes a power adapter with circuitry that automatically transitions to an "off" state, drawing no input power, when it determines the connected device is no longer drawing a significant load (’833 Patent, Abstract). One embodiment achieves this using a load sensing device that monitors the pulse width and repetition frequency of the power converter's switching circuit to determine the load, rather than directly measuring voltage or current (’833 Patent, col. 9:26-42).
• Technical Importance: This technology provides a solution to the growing regulatory and consumer demand for energy-efficient electronics by actively eliminating wasteful standby power consumption in chargers (’833 Patent, col. 2:5-13).

Key Claims at a Glance

• The complaint asserts independent Claims 24 and 33 (Compl. ¶52, ¶62).
• Essential elements of independent Claim 24 include:
  • A power device for an electronic device.
  • Power circuitry for converting voltage and determining an "off" state.
  • Switching circuitry to electrically activate the power circuitry to an "on" state.
  • A load sensing portion operable to sense one or more pulses and determine the power or load being drawn from the device based thereon.
• Essential elements of independent Claim 33 include:
  • A power device according to Claim 24.
  • Wherein the load sensing portion measures the pulses from transformer control circuitry which controls a power state of a transformer.
• The complaint also asserts dependent Claim 36 (Compl. ¶62).

Multi-Patent Capsule

• Patent Identification: U.S. Patent No. 7,960,648, "Energy Saving Cable Assemblies," issued June 14, 2011.
• Technology Synopsis: As a continuation of the technology in the ’833 patent, this patent discloses a cable assembly with circuitry to reduce or eliminate phantom power draw (Compl. ¶21, ¶24). The system monitors the power state of a connected electronic device, for example by monitoring the frequency of pulses from a transformer, and automatically disconnects input power when the device is in a reduced power state (e.g., turned off or fully charged) (’648 Patent, Abstract; col. 15:1-4).
• Asserted Claims: Independent Claims 31 and 39 are asserted (Compl. ¶52, ¶67).
• Accused Features: The internal monitoring and switching circuitry of the Mophie Wireless Charger, which is alleged to sense when a device is fully charged and automatically enter an "off" state to reduce power consumption (Compl. ¶51-52).

III. The Accused Instrumentality

Product Identification

• The accused products are the "Mophie 20W USB-C PD Wall Charger," "Mophie Speedport 20 20W GaN fast wall charger," "Mophie Speedport 30 30W GaN fast wall charger," and the "Mophie Wireless Charging Base" (Compl. ¶¶25, 32, 39, 46).

Functionality and Market Context

• The complaint alleges the accused wall chargers are compact AC-to-DC power converters designed for mobile devices (Compl. ¶¶26, 33, 40). A key allegation is that their physical dimensions are small enough to avoid blocking adjacent wall outlets and fall within the specific size limitations claimed by the ’794 Patent (Compl. ¶¶27, 31, 34, 38, 41, 45). An image provided in the complaint shows the Mophie 20W USB-C PD Wall Charger, a compact white rectangular unit with foldable AC prongs (Compl. ¶25, p. 9).
• The complaint alleges the Mophie Wireless Charger is a Qi-compliant wireless charging pad that contains internal circuitry to monitor the charging status of a device placed on it (Compl. ¶¶47, 51). The complaint makes a specific technical allegation that this charger utilizes 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" and to enter an "off" state when the device is charged (Compl. ¶51). An image shows the Mophie Wireless Charger as a flat, black, square charging pad with a connected power cable (Compl. ¶46, p. 14).

IV. Analysis of Infringement Allegations

The complaint references, but does not include, claim chart exhibits. The following summary is based on the narrative allegations in the complaint.

RE48,794 E Infringement Allegations

7,910,833 E Infringement Allegations

Identified Points of Contention

• Scope and Factual Questions (’794 Patent): The infringement analysis for the wall chargers may focus on claim construction and factual measurement. A central question will be how terms like "longitudinal length" and "width of the housing outer profile" are defined and measured, particularly with respect to the products' curved edges and non-uniform shapes. The dispute may then turn on factual evidence from expert measurements of the accused products to determine if they meet the specific dimensional limitations of Claim 1.
• Technical and Evidentiary Questions (’833 and ’648 Patents): For the wireless charger, the infringement analysis raises a key technical question: what is the precise mechanism of its load-sensing circuitry? The complaint makes a specific allegation of pulse frequency sensing. The case may depend on evidentiary findings from reverse engineering to determine whether the accused product actually operates in this manner, as taught in the patent embodiments, or if it uses a more conventional and potentially non-infringing method like simple voltage or current threshold sensing.

V. Key Claim Terms for Construction

Term from the ’794 Patent: "width of the housing outer profile"

• Context and Importance: This term is critical because infringement of Claim 1 hinges on a specific numerical dimension ("less than 1.75 inches"). The definition of "outer profile" will determine which parts of the charger's body are included in the measurement, which is crucial for products with curved or complex surfaces. Practitioners may focus on this term because its interpretation could directly decide the infringement question on a factual, measurable basis.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: A party could argue the term should be given its plain and ordinary meaning, encompassing the maximum lateral dimension of the housing at any point, as this ensures the "no interference" objective of the claim is met (’794 Patent, col. 13:52-59).
  • Evidence for a Narrower Interpretation: A party might point to the patent figures, such as the cross-section in FIG. 11 and front view in FIG. 10, which show specific profiles, arguing the "outer profile" is limited to the main body and excludes minor protrusions or the specific curvature shown in the embodiments, potentially leading to a smaller measured width.

Term from the ’833 Patent: "a load sensing portion operable to sense one or more pulses"

• Context and Importance: This term is central to the alleged infringement by the wireless charger. The complaint's theory is that the charger senses pulse frequency. The construction of "sense...pulses" will determine whether the claim is limited to the specific method described in the patent's embodiments or if it can cover other forms of power monitoring.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: A party might argue that "sense one or more pulses" is a broad functional description and is not limited to any specific characteristic of the pulse, thereby covering any circuit that detects the presence or absence of power pulses.
  • Evidence for a Narrower Interpretation: The detailed description repeatedly explains the load sensing in terms of recognizing "how slow or fast the pulse is repeated to determine the load" (’833 Patent, col. 9:35-38). A party could argue that these specific descriptions of sensing pulse width and frequency limit the scope of the claim term to this particular technical approach, distinguishing it from conventional voltage or current sensing.

VI. Other Allegations

Willful Infringement

• The complaint's Prayer for Relief requests a finding that infringement was "willful, wanton, and deliberate" (Compl. p. 19, ¶C). However, the body of the complaint does not allege specific facts that would typically support such a claim, such as Defendants' pre-suit knowledge of the patents or any communication between the parties prior to the lawsuit.

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

1. A core issue will be one of claim construction and measurement: can the dimensional terms in the ’794 patent, such as "width of the housing outer profile," be construed in a way that the accused wall chargers, upon expert measurement, definitively fall within the claimed sub-1.75-inch limitation?
2. A key evidentiary question will be one of technical mechanism: does the accused wireless charger’s load-sensing circuitry function by monitoring the frequency of pulses from its power converter, as specifically taught in the ’833 and ’648 patents and alleged in the complaint, or does it employ a different, potentially non-infringing technology to determine when a device is fully charged?