DCT
1:22-cv-23198
Voltstar Tech Inc v. Walgreen Co
Key Events
Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Voltstar Technologies, Inc. (Illinois)
- Defendant: Walgreen Co. (Illinois, registered to do business in Florida)
- Plaintiff’s Counsel: Sriplaw PLLC
- Case Identification: 1:22-cv-23198, S.D. Fla., 10/03/2022
- Venue Allegations: Venue is alleged based on Defendant having a regular and established place of business in the district and committing acts of infringement there, with accused products available for purchase in-store and online within the district.
- Core Dispute: Plaintiff alleges that Defendant’s private-label USB wall chargers infringe a patent related to the compact physical design of such chargers.
- Technical Context: The technology concerns the mechanical design and packaging of AC-to-DC power adapters to minimize their physical footprint, a key feature for consumer electronics accessories used with crowded power strips and wall outlets.
- Key Procedural History: The asserted patent, 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 requirement 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 may give rise to a defense of intervening rights for any infringement that occurred prior to the reissue date.
Case Timeline
| Date | Event |
|---|---|
| 2008-05-21 | Earliest Priority Date (Application for '581 patent filed) |
| 2015-05-05 | Original U.S. Patent No. 9,024,581 Issues |
| 2021-10-26 | U.S. Reissue Patent No. RE48,794 E Issues |
| 2022-10-03 | Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Reissue Patent No. RE48,794 E: "Charger Plug With Improved Package"
The Invention Explained
- Problem Addressed: The patent addresses the problem of bulky AC-to-DC power adapters ("charger plugs") that are often so large they block access to adjacent receptacles on a standard wall outlet or power strip. The patent also notes that prior manufacturing methods, such as insert-molding electrical blades into a plastic housing, were costly and complex. (RE48,794 E, col. 1:41-57; col. 2:1-11).
- The Patented Solution: The invention is a charger with a specific, compact physical package designed to avoid obstructing adjacent outlets. The design achieves this through its specific dimensional limits and a construction method that avoids insert-molding. Instead, the electrical blades are slidably mounted into the housing and connected to the internal circuit board via spring contacts, simplifying assembly and enabling a smaller form factor. (’794 Patent, Abstract; col. 4:11-24).
- Technical Importance: This approach sought to create a more user-friendly and less expensive charger by focusing on the external physical dimensions and the internal mechanical assembly, rather than the electrical power conversion circuitry itself. (’794 Patent, col. 1:15-18).
Key Claims at a Glance
- The complaint asserts infringement of at least Claim 1. (Compl. ¶34).
- Independent Claim 1: A charger plug comprising:
- A housing with a front wall, an outer profile, and a rear end.
- First and second separate blade members with prong portions extending from the front wall.
- A DC connector with an aperture to receive a power cord plug.
- The housing is 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 "outer profile" has "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 does not explicitly reserve the right to assert dependent claims but alleges infringement of "at least one of the claims." (Compl. ¶23).
III. The Accused Instrumentality
Product Identification
- "Infinitive Wall Charger 2.4 AMP Dual Port" ("Dual Port Wall Charger") (Compl. ¶18).
- "Infinitive Lightning Cable Charge & Sync Combo Pack" ("Lightning Cable Wall Charger") (Compl. ¶25).
Functionality and Market Context
- The accused products are AC-to-DC USB wall chargers sold by Walgreens. (Compl. ¶¶18, 25). The complaint alleges they are designed to connect between a standard AC wall outlet and a device, like a mobile phone, to provide DC charging power. (Compl. ¶¶19, 26).
- The complaint provides an image of the "Dual Port Wall Charger," a grey, compact, rectangular charger with two USB ports and foldable prongs. (Compl. p. 5).
- The complaint also provides an image of the "Lightning Cable Wall Charger," a white, compact, rectangular charger with fixed prongs. (Compl. p. 7).
- The core of the infringement allegation centers on the "reduced plug-size" of these chargers, which allegedly allows them to be used without blocking adjacent outlets, a key feature claimed by the patent. (Compl. ¶¶20, 27).
IV. Analysis of Infringement Allegations
The complaint alleges that both accused products infringe at least Claim 1 of the ’794 patent. The core of the infringement theory is that the accused chargers possess the specific compact dimensions and non-interfering shape recited in the claim. The complaint provides specific measurements for each accused product to support these allegations.
RE48,794 E Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A charger plug...including a housing, the charger plug comprising: first and second separate blade members secured within the housing so as to have prong portions of the blade members positioned in order to extend in a first direction from a front wall of the housing... | Walgreens sells the Dual Port Wall Charger and Lightning Cable Wall Charger, each of which is a charger plug with a housing and prongs that extend from a front wall for insertion into an AC power source. | ¶¶18-19, 25-26 | col. 13:26-34 |
| the charger plug including a DC connector having an aperture adapted to removably receive a corresponding power cord plug end for transmitting DC power to the rechargeable electronic device; | The accused chargers are advertised for connecting to devices such as mobile phones to provide DC power. The image of the Dual Port Wall Charger shows it includes USB ports (DC connectors) for this purpose. | ¶19, 26 | col. 13:35-39 |
| i) 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, and | The complaint alleges specific measurements for the accused products that meet these limitations. • Dual Port Wall Charger: longitudinal length of approx. 1.169 inches and width of approx. 1.274 inches. • Lightning Cable Wall Charger: longitudinal length of approx. 0.956 inches and width of approx. 0.941 inches. |
¶¶24, 31 | col. 14:3-10 |
| ii) the outer profile having no interference with an adjacent receptacle of the power source...when a like charger plug is mounted in all available orientations in any of the other receptacles, | The complaint alleges that due to their "reduced plug-size," both accused chargers do not "block or interfere with the use of adjacent outlets" when plugged into a source of AC power. | ¶¶20, 27 | col. 14:11-19 |
| so that when space is limited...the power cord plug end may be conveniently received by the DC connector...while leaving the charger plug connected to the receptacle. | The complaint alleges that the size and shape of the accused chargers allow a power cord to be "easily inserted into and removed from" the charger while it remains plugged into the wall, and the cord can be removed "without removal of the charger from the source of AC power." | ¶¶21, 28 | col. 14:20-27 |
Identified Points of Contention
- Scope Questions: A central question may be the meaning of "no interference with an adjacent receptacle." Does this require zero physical contact of any kind, or does it mean merely not obstructing the use of the adjacent outlet? The parties may dispute the standard for what constitutes "interference."
- Technical Questions: While the complaint provides specific measurements, the method of measurement for "longitudinal length" and "width of the housing outer profile" could become a point of dispute. For example, do these measurements include foldable prongs, or just the main body of the housing? The proof for the "no interference" limitation will require evidence beyond simple measurements, potentially involving demonstrations with standard NEMA receptacles.
V. Key Claim Terms for Construction
The Term: "outer profile"
Context and Importance: This term is critical because two key limitations—the width measurement and the "no interference" requirement—depend on how the "outer profile" is defined and measured. Practitioners may focus on this term because its definition will determine whether the accused products' specific shapes and dimensions fall within the claim scope.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: Claim 1 defines the outer profile in relation to a "perimeter of the front wall" and a "plug body extending rearward." (’794 Patent, col. 13:46-51). This could support an interpretation covering the overall three-dimensional shape of the housing.
- Evidence for a Narrower Interpretation: The figures consistently show a specific rounded, somewhat ovoid or rectangular shape with tapered edges (e.g., ’794 Patent, Figs. 1, 10, 12). A defendant might argue that "outer profile" is implicitly limited by these consistent disclosures to a shape substantially similar to what is depicted, rather than any arbitrary shape that meets the dimensions.
The Term: "no interference with an adjacent receptacle"
Context and Importance: This is a negative functional limitation that is at the heart of the invention's purported benefit. The case may turn on whether the plaintiff can prove this absence of interference, and under what standard.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The plain language "no interference" could be argued to set a strict, absolute standard. The patent's background criticizes prior art plugs for providing "little or no interference" and seeks to improve upon that, suggesting a high bar was intended. (’794 Patent, col. 1:47-49).
- Evidence for a Narrower Interpretation: The claim requires non-interference "when a like charger plug is mounted in all available orientations in any of the other receptacles." (’794 Patent, col. 14:14-16). This could be interpreted not as a universal "no interference" standard with any possible plug, but as a more specific test: two of the patented plugs must be able to coexist in adjacent outlets. The patent's goal is practical usability, which might permit incidental contact so long as the adjacent outlet remains fully functional.
VI. Other Allegations
- Indirect Infringement: The prayer for relief requests a judgment of induced infringement (Compl. p. 9, Prayer A). However, the body of the complaint focuses on direct infringement by Defendant's making and selling of the accused products and does not plead specific facts to support the knowledge and specific intent required for a claim of inducement.
- Willful Infringement: The complaint alleges willful infringement and seeks enhanced damages (Compl. p. 9, Prayer C). The complaint does not allege any pre-suit knowledge by the Defendant. The basis for willfulness appears to be post-filing conduct, where the filing of the lawsuit itself provides the requisite knowledge of infringement.
VII. Analyst’s Conclusion: Key Questions for the Case
- A central issue will be one of claim scope and proof: what is the evidentiary standard for proving the negative limitation of "no interference with an adjacent receptacle"? The case may hinge on whether simple measurements suffice or if physical demonstrations under various conditions are required to meet the plaintiff's burden.
- A second key question will be one of prosecution history: The patent-in-suit is a reissue that narrowed the original claims by adding a width limitation. This raises the possibility of a defense of intervening rights, which could shield the defendant from damages for any infringing sales that occurred before the reissue patent was granted on October 26, 2021.
- Finally, the dispute may involve a definitional question: how is the "outer profile" of the charger housing measured? The outcome of this claim construction issue will directly impact whether the accused products, with their specific shapes and foldable prongs, meet the dimensional limitations of the asserted claim.