Dense Matrix LLC v. Purelifi Ltd

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Dense Matrix LLC (New Mexico)
  • Defendant: pureLiFi Ltd (Scotland)
  • Plaintiff’s Counsel: Rabicoff Law LLC
• Case Identification: 2:25-cv-00819, E.D. Tex., 08/19/2025
• Venue Allegations: Plaintiff alleges venue is proper because Defendant is a foreign corporation and has committed acts of patent infringement in the district.
• Core Dispute: Plaintiff alleges that Defendant’s light-based communication products infringe a patent related to solid-state lighting systems with broadband optical communication capabilities.
• Technical Context: The dispute centers on "Li-Fi" (Light Fidelity) technology, which uses visible light from sources like LED bulbs to transmit high-speed data as an alternative to radio-frequency systems like Wi-Fi.
• Key Procedural History: The complaint is the initiating document in this litigation; no prior litigation, licensing history, or other procedural events are mentioned.

Case Timeline

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

U.S. Patent No. 9,826,597 - “Solid state light system with broadband optical communication capability”

• Patent Identification: U.S. Patent No. 9,826,597, “Solid state light system with broadband optical communication capability,” issued November 21, 2017.

The Invention Explained

• Problem Addressed: The patent describes a technological environment where building systems (e.g., HVAC, lighting) operate independently and where conventional wireless communication like Wi-Fi has limitations (’597 Patent, col. 1:43-51). The goal is to create "smart buildings" that can both automatically control their environment and provide robust data communication (’597 Patent, col. 2:38-44).
• The Patented Solution: The invention proposes a system integrated into a conventional light fixture, such as a standard light bulb or tube. This system uses light-emitting diodes (LEDs) that serve a dual purpose: providing illumination and acting as an optical transceiver for high-speed data transmission (’597 Patent, Abstract). A controller manages both the light output and the data communication over an optical network, as depicted in the block diagram of Figure 5 (’597 Patent, col. 2:49-54; Fig. 5).
• Technical Importance: The described technology combines the ubiquitous infrastructure of lighting with high-speed data networking, offering a potential alternative to radio-frequency communications that may be advantageous in certain environments (’597 Patent, col. 4:5-23).

Key Claims at a Glance

• The complaint asserts infringement of "one or more claims" and refers to "Exemplary '597 Patent Claims" without identifying specific claims (Compl. ¶11). Independent claim 1 is representative of the system described.
• Essential elements of Independent Claim 1 include:
  • A system comprising one or more LEDs electrically coupled to a standardized electrical connector (e.g., for a conventional light bulb).
  • An optical transceiver with at least one transmitter and receiver.
  • At least one of the LEDs is associated with a "predetermined geographical position."
  • The system is optically coupled to a "broadband optical network greater than 1 Mbps."
  • A controller is coupled to the LEDs to adjust light output and communicate over the optical network.
  • A mobile device receives the geographical position data from the LED light and provides information about a nearby user or object.
• The complaint does not explicitly reserve the right to assert dependent claims but refers to infringement of "one or more claims" (Compl. ¶11).

III. The Accused Instrumentality

Product Identification

The complaint does not identify any accused products by name (Compl. ¶11). It refers generally to "Exemplary Defendant Products" that are detailed in claim charts attached as Exhibit 2 (Compl. ¶¶ 11, 16). Exhibit 2 was not filed with the public complaint.

Functionality and Market Context

The complaint alleges that the accused products "practice the technology claimed by the '597 Patent" (Compl. ¶16). Based on this allegation, the accused products are understood to be systems that use LED lighting for optical data communication. The complaint does not provide sufficient detail for analysis of the products' specific functionality or market positioning.

IV. Analysis of Infringement Allegations

The complaint references claim charts in an unprovided "Exhibit 2" to detail its infringement allegations (Compl. ¶17). Without this exhibit, the infringement theory is based on the complaint's narrative assertions. The complaint alleges that Defendant’s "Exemplary Defendant Products" directly infringe by "making, using, offering to sell, selling and/or importing" products that "satisfy all elements of the Exemplary '597 Patent Claims" (Compl. ¶¶ 11, 16).

No probative visual evidence provided in complaint.

Identified Points of Contention

• Scope Questions: A central dispute may concern the scope of "predetermined geographical position." The parties may contest whether this requires a specific format (e.g., GPS coordinates, indoor mapping data) and how the accused products allegedly associate an LED with such a position and transmit it to a mobile device.
• Technical Questions: A key evidentiary question will be whether the accused products create or are coupled to a "broadband optical network greater than 1 Mbps" as required by the claim. The complaint's conclusory allegations will require factual support demonstrating the specific architecture and data rates of the accused systems.

V. Key Claim Terms for Construction

• The Term: "predetermined geographical position" (Claim 1)

  • Context and Importance: This term appears central to distinguishing the claimed invention from a generic data-transmitting light source. Its construction will determine what type of location information the accused product must transmit to infringe. Practitioners may focus on this term because indoor positioning is a key feature highlighted in the patent.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification discusses tracking a wearer of a badge by mapping each light to an "indoor position" and providing the badge with a "local coordinate," suggesting the term could cover relative or symbolic indoor locations, not just absolute geographic coordinates (’597 Patent, col. 12:12-18).
    • Evidence for a Narrower Interpretation: The use of "geographical" could be argued to limit the term to established coordinate systems like latitude/longitude. The patent’s lack of a specific definition for "geographical" may lead parties to argue for its plain and ordinary meaning, which could be narrower than a generalized "location."

• The Term: "broadband optical network" (Claim 1)

  • Context and Importance: The existence of a "network" is a critical structural limitation. Whether the accused products form or connect to such a network, as opposed to operating in a point-to-point fashion, will be a key infringement question.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The patent describes "broadband" in relative terms, comparing it to the speeds of "WiFi, cable modem, or DSL transmission" (’597 Patent, col. 7:26-34). This could support a flexible definition based on contemporaneous industry standards rather than a fixed data rate, although Claim 1 adds the specific floor of "greater than 1 Mbps."
    • Evidence for a Narrower Interpretation: The patent repeatedly discusses integrating with building-wide systems like BACnet and forming mesh networks (e.g., Fig. 8), suggesting a "network" requires a multi-node, interconnected system capable of routing, not just a simple transmitter-receiver link (’597 Patent, col. 7:25-30; col. 23:26-31).

VI. Other Allegations

• Indirect Infringement: The complaint alleges induced infringement, stating that Defendant distributes "product literature and website materials" that instruct end users on how to use the accused products in an infringing manner (Compl. ¶14).
• Willful Infringement: The complaint does not contain an explicit allegation of willful infringement. However, it pleads that the filing and service of the complaint provides Defendant with "Actual Knowledge of Infringement," which may form the basis for alleging post-filing willful infringement or enhanced damages (Compl. ¶¶ 13-14).

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

• An Evidentiary Question of Product Functionality: As the complaint's technical allegations are contained entirely within an unprovided exhibit, a threshold issue will be whether discovery produces evidence that the accused products in fact perform the specific functions claimed, most notably associating an LED with a "predetermined geographical position" and transmitting that data to a mobile device over a "broadband optical network."
• A Definitional Question of Claim Scope: The case will likely depend on the judicial construction of "predetermined geographical position." The core legal question will be whether this term is broad enough to cover the type of location-aware data allegedly transmitted by the accused Li-Fi systems, or if it is limited to a more specific implementation not practiced by the defendant.