Voltstar Tech Inc v. Alogic USA LLC

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Voltstar Technologies, Inc. (Illinois)
  • Defendant: Alogic USA LLC (California)
  • Plaintiff’s Counsel: Sriplaw, PLLC.
• Case Identification: 4:23-cv-01257, N.D. Cal., 03/17/2023
• Venue Allegations: Venue is based on allegations that the Defendant has committed acts of infringement and maintains a regular and established place of business within the Northern District of California.
• Core Dispute: Plaintiff alleges that Defendant’s compact USB-C power adapters infringe a reissue patent related to the specific dimensional and functional characteristics of charger plugs designed to avoid obstructing adjacent wall outlets.
• Technical Context: The technology concerns the design and manufacture of small form-factor AC-to-DC power converters, a market driven by the proliferation of portable electronic devices requiring compact and convenient charging solutions.
• Key Procedural History: The patent-in-suit, RE48,794, is a reissue of U.S. Patent No. 9,024,581. The complaint notes that the reissue process amended original Claim 1 to be more dimensionally restrictive, changing a length limitation from "equal to or less than 2.0 inches" to "less than 2.0 inches" and adding a new width limitation of "less than 1.75 inches." This narrowing amendment during reissue will likely be a central focus of claim construction and infringement analysis.

Case Timeline

Date	Event
2008-05-21	Earliest Priority Date ('794 Patent)
2009-11-26	Original patent application published
2015-05-05	Original U.S. Patent No. 9,024,581 issued
2015-05-05	Plaintiff allegedly ceased selling patented articles
2021-10-26	U.S. Reissue Patent No. RE48,794 E issued
2023-03-17	Complaint Filed

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's background section identifies several problems with prior art power chargers: they are often bulky, blocking adjacent electrical outlets; they can be expensive and difficult to manufacture due to processes like insert-molding electrical blades and hand-soldering connections to the internal circuit board (RE48,794 E, col. 1:41-59, col. 2:11-28).
• The Patented Solution: The invention is a "reduced plug-size charger plug" designed to be compact and easily manufactured (RE48,794 E, Abstract). It achieves this through a specific housing construction that avoids interference with adjacent outlets and uses slidably mounted blades that connect to the internal printed circuit board (PCB) via spring contacts, which obviates the need for insert molding and soldering (RE48,794 E, Abstract; col. 3:12-28). This mechanical, solder-less connection is described as a key aspect of the improved package design.
• Technical Importance: The described approach sought to lower manufacturing costs and time while creating a more user-friendly, compact charger that could be used in crowded power strips without obstructing other plugs (RE48,794 E, col. 1:41-48).

Key Claims at a Glance

• The complaint asserts infringement of at least Claim 1 ('794 Patent, col. 13:20-14:3; Compl. ¶34).
• Independent Claim 1 requires, in essence:
  • A charger plug housing containing circuitry to convert AC to DC power.
  • First and second separate blade members secured within the housing to plug into a power source.
  • A DC connector (e.g., a USB port) to provide power to a device via a power cord.
  • The housing must have 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" must have "no interference with an adjacent receptacle of the power source located on all sides" when a like charger is in another receptacle.
  • The configuration must allow for convenient mounting and removal of the power cord even when space is limited by an obstacle.
• The complaint alleges infringement of "at least one claim" of the patent (Compl. ¶33).

III. The Accused Instrumentality

Product Identification

The complaint identifies two accused products: the "Alogic 30W Rapid Power USB-C GaN Charger" (the "Alogic Charger") and the "Journey 30W USB-C GaN Charger" (the "Journey Charger") (Compl. ¶¶18, 25).

Functionality and Market Context

• The complaint alleges that both products are compact AC-to-DC chargers that connect a wall outlet to a mobile device for charging (Compl. ¶¶19, 26). The complaint provides an image of the Alogic Charger (Compl. p. 5, image).
• The core of the infringement allegation is that the accused chargers possess the specific size, shape, and non-interfering characteristics claimed by the patent (Compl. ¶¶20, 24, 27, 31). A similar image is provided for the Journey Charger (Compl. p. 7, image).
• The complaint alleges the chargers are designed such that a power cord can be inserted and removed while the charger remains plugged into the wall (Compl. ¶¶21, 28).

IV. Analysis of Infringement Allegations

The complaint references claim charts attached as exhibits, but the exhibits were not included with the filing (Compl. ¶¶22, 29). The narrative allegations for infringement of U.S. Reissue Patent No. RE48,794 E are summarized below.

The complaint alleges that the accused Alogic and Journey chargers meet the general requirements of Claim 1 by functioning as AC-to-DC converters that connect an AC power source to a rechargeable device via a DC power cord (Compl. ¶¶19, 26). Infringement of the structural limitations is premised on the chargers having a housing, electrical blades for a wall outlet, and a DC connector port (e.g., USB-C) (Compl. ¶¶19, 21, 26, 28).

The central infringement allegations map to the specific dimensional and functional limitations of the claim. For the dimensional requirements of Claim 1(i), the complaint asserts the Alogic Charger has a longitudinal length of approximately 1.206 inches and a width of approximately 1.210 inches, and the Journey Charger has a length of 1.207 inches and a width of 1.211 inches, all of which fall within the claimed "less than 2.0 inches" and "less than 1.75 inches" limits (Compl. ¶¶24, 31).

For the functional "no interference" limitation of Claim 1(ii), the complaint makes the direct allegation that "the Alogic Charger does not block or interfere with the use of adjacent outlets" (Compl. ¶20), with a parallel allegation for the Journey Charger (Compl. ¶27).

Identified Points of Contention

• Technical Question: The claim requires "no interference with an adjacent receptacle ... on all sides ... in all available orientations." This is a broad functional requirement. A key question will be whether the accused products meet this standard across all standard NEMA-compliant outlet configurations, or if a configuration exists where interference occurs, which may support a non-infringement defense.
• Scope Question: A dispute may arise over the proper methodology for measuring the "longitudinal length" and "width of the housing outer profile." The defense may argue for a different measurement technique or interpretation of "outer profile" that places the accused products outside the claimed dimensional ranges.

V. Key Claim Terms for Construction

"a width of the housing outer profile"

• Context and Importance: This term was added during the reissue proceeding that narrowed the original patent's claims, suggesting it was critical for patentability. Its construction will be central to infringement, as the complaint's allegations rely on specific measurements of the accused products falling under the 1.75-inch limit (Compl. ¶¶24, 31). Practitioners may focus on this term because its definition—specifically, what constitutes the "profile" to be measured—is not explicitly defined in the patent.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The patent uses the general term "outer profile" without restricting it to a specific cross-section, which may support a plain meaning interpretation as the maximum width of the housing body ('794 Patent, col. 13:48-51).
  • Evidence for a Narrower Interpretation: A party could argue that the term should be interpreted in light of the patent figures, such as the front elevation views in FIG. 10 and FIG. 15, potentially limiting the "profile" to a specific plane or excluding minor protrusions not depicted as part of the main body.

"no interference with an adjacent receptacle"

• Context and Importance: This functional language appears absolute. The viability of the infringement claim depends on proving the accused products satisfy this condition. The defense will likely scrutinize this term for ambiguity and as a basis for non-infringement or invalidity arguments.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The patent's objective is to solve the problem of bulky chargers in common use scenarios (e.g., a standard duplex wall outlet or power strip) ('794 Patent, col. 1:41-48). A party may argue the term should be understood in this practical context, not as a mathematically absolute prohibition covering every conceivable non-standard outlet design.
  • Evidence for a Narrower Interpretation: The claim language itself is unconditional ("no interference ... on all sides"). A party could argue this requires the charger to be non-interfering in every orientation on any standard multi-receptacle plate, as defined by NEMA standards referenced in the specification ('794 Patent, col. 12:13-15). If an accused product can be shown to interfere in even one such standard configuration, it may fall outside the claim scope.

VI. Other Allegations

Willful Infringement

The prayer for relief seeks a finding of willful infringement (Compl. p. 9, ¶C). However, the body of the complaint does not plead specific facts to support this allegation, such as evidence of Defendant's pre-suit knowledge of the patent or deliberate copying of the patented technology. The allegation rests on the general assertion that the claims were "substantially known publicly at least as early as 2011" (Compl. ¶15), without tying that knowledge specifically to the Defendant.

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

1. A central issue will be one of evidentiary proof and claim construction: Can the Plaintiff prove, and can the Defendant disprove, that the accused chargers meet the precise dimensional limitations of "less than 2.0 inches" in length and "less than 1.75 inches" in width? The outcome may depend heavily on the court's construction of "width of the housing outer profile" and the measurement methodologies employed by each side's experts.

2. A second key question will be the scope of the functional limitation: Does the phrase "no interference with an adjacent receptacle" constitute an absolute requirement? The case may turn on whether the accused products can be shown to interfere with any standard outlet configuration, which could either defeat the infringement claim or, if infringement is found, raise questions about the patent's validity over prior art.

3. The impact of the reissue proceeding will be a significant underlying theme. Arguments made by the patentee to narrow the claims and add the width limitation will likely create prosecution history estoppel, limiting the scope of infringement that can be asserted and providing a roadmap for the Defendant’s invalidity and non-infringement arguments.