Principal Lighting Group,

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Principal Lighting Group, LLC (Delaware)
  • Defendant: Grimco, Inc. (Missouri)
  • Plaintiff’s Counsel: Jackson Walker LLP
• Case Identification: 6:20-cv-00998, W.D. Tex., 10/27/2020
• Venue Allegations: Plaintiff alleges venue is proper in the Western District of Texas because Defendant maintains multiple business locations and conducts business within the district, and because the alleged acts of infringement occurred, in part, within the district.
• Core Dispute: Plaintiff alleges that Defendant’s LED light bars and associated components, designed for use in lighted signs, infringe a patent related to retrofitting existing sign housings with modern lighting assemblies.
• Technical Context: The technology concerns the replacement of traditional high-voltage, gas-discharge lamps (e.g., fluorescent tubes) in commercial signs with more energy-efficient, low-voltage LED lighting systems.
• Key Procedural History: The complaint alleges Defendant had pre-suit notice of the patent-in-suit as of February 2018. Subsequent to the filing of this complaint, the asserted patent was subject to an Inter Partes Review (IPR) proceeding, IPR2021-00968. This proceeding resulted in a certificate issued on March 8, 2023, cancelling all claims (1-20) of the patent. The cancellation of all asserted claims presents a dispositive issue for the litigation.

Case Timeline

Date	Event
2010-11-24	U.S. Patent No. 9,311,835 Priority Date
2016-04-12	U.S. Patent No. 9,311,835 Issue Date
2018-02-15	Alleged pre-suit notice of infringement to Defendant
2020-10-27	Complaint Filing Date
2023-03-08	U.S. Patent No. 9,311,835 claims 1-20 cancelled via IPR Certificate

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

U.S. Patent No. 9,311,835 - "Lighting Mount for Interior-Lighted Signage and Method of Retrofitting a Lighted Sign"

• Patent Identification: U.S. Patent No. 9,311,835, "Lighting Mount for Interior-Lighted Signage and Method of Retrofitting a Lighted Sign," issued April 12, 2016.

The Invention Explained

• Problem Addressed: The patent addresses the challenge of retrofitting existing internally-lit signs, which were originally built for high-voltage gas-discharge lamps (like fluorescent tubes), with modern, low-voltage LED lights. (’835 Patent, col. 1:21-34). The goal is to perform this replacement without requiring significant and costly modifications to the sign's existing mechanical structure, particularly the sockets that held the old lamps. (’835 Patent, col. 2:35-47).
• The Patented Solution: The invention is a lamp support assembly designed as a "drop-in replacement." It consists of an elongate member (e.g., an extruded bar) to which LED units are attached, and a pair of end caps. (’835 Patent, Abstract). These end caps are specifically designed to mechanically engage the existing electro-mechanical mounts or sockets from the old gas-discharge lamps, but are made of an electrically insulative material and carry no electrical conductors for powering the LEDs. (’835 Patent, col. 2:56-65). This allows the assembly to use the original mounting points for physical support only, while the LEDs are powered separately by low-voltage wiring.
• Technical Importance: This approach facilitates a less expensive and simpler conversion to energy-efficient lighting, as it reuses the original sign’s structural support points and avoids the need to install new custom brackets. (’835 Patent, col. 2:44-47).

Key Claims at a Glance

• The complaint asserts independent claim 1. (Compl. ¶21). It also identifies claims 13 and 19 as independent but bases its infringement allegations on claim 1. (Compl. ¶17).
• Essential elements of independent claim 1 include:
  • An elongate support member for supporting electric lamp units.
  • One and only one end cap at each opposite end portion of the support member, configured to frictionally engage the support member.
  • A mechanical coupling element on the outwardly-facing side of each end cap, configured to engage a single electro-mechanical mount for a gas-discharge lamp.
  • The mechanical coupling element comprises electrically insulative material and does not retain any electrical conductors for powering the lamp units.
  • The assembly is releasably supportable between two and only two such mounts.

III. The Accused Instrumentality

Product Identification

The complaint names the HanleyLED Kestrel Stick, HanleyLED PhoenixNRG Bar, HanleyLED Wingspan, G2G AnPro Stick, and G2G Trident Stick as the "Accused Products." (Compl. ¶21).

Functionality and Market Context

• The Accused Products are described as light support assemblies for use in lighted signs. (Compl. ¶21). The complaint alleges these products include an elongate member for supporting LEDs and are designed for use with electrically insulative end caps. (Compl. ¶23-¶24). The complaint includes an image of the HanleyLED Wingspan product with an optional "Retrofit Connector," described as an "end cap for mounting... into HO sockets for lamp replacement." (Compl. p. 6). This suggests the products are marketed for the specific retrofit purpose addressed by the patent. Other images depict the LED bars and separate end cap components. For example, an image of the G2G AnPro Stick shows the LED bar and separate plastic end caps which appear to be designed for mounting. (Compl. p. 7).
• The complaint alleges that Defendant has sought to displace and undercut the Plaintiff's products in the market with these Accused Products. (Compl. ¶30).

IV. Analysis of Infringement Allegations

’835 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
an elongate support member for supporting a plurality of electric lamp units, said elongate support member having opposite end portions;	The Accused Products are alleged to include an elongate support member, such as an extruded bar, for supporting LED modules.	¶23	col. 4:57-61
one and only one end cap at each of said opposite end portions of said elongate support member, each of said end caps having an inwardly-facing side and an outwardly-facing side, said inwardly-facing sides configured to frictionally engage and be supported at a respective one of said opposite end portions of said elongate support member;	The Accused Products are alleged to include or be designed for use with an end cap at each end that frictionally engages the elongate support member.	¶24	col. 4:62-65
a mechanical coupling element at each of said outwardly-facing sides of said end caps, said mechanical coupling element configured to engage a single electro-mechanical mount for a gas-discharge lamp...	The end caps are alleged to be configured to engage a mount for a gas-discharge lamp, as shown in a product image for the "Retrofit Connector."	¶25; p. 6	col. 5:19-28
...wherein said mechanical coupling element comprises electrically insulative material and does not retain any electrical conductors along or through said mechanical coupling element for powering the plurality of electric lamp units;	The end caps are alleged to be electrically insulative.	¶24	col. 9:5-11
and wherein said elongate support member and said end caps are releasably supportable by and between two and only two of the mounts...	The complaint alleges infringement of the full claim, which requires this capability, and the purpose of the "Retrofit Connector" implies this function.	¶26; p. 6	col. 9:12-18

Identified Points of Contention

• Scope Questions: A central question concerns the scope of "electro-mechanical mount for a gas-discharge lamp." The dispute may focus on whether the accused end caps are "configured to engage" the specific legacy sockets contemplated by the patent (e.g., "Kulka sockets"), or if merely fitting into any generic tube lamp holder is sufficient. (Compl. p. 6; ’835 Patent, col. 5:25-28).
• Technical Questions: Evidence will be needed to determine if the accused end caps are indeed "electrically insulative" and "do not retain any electrical conductors," as required by the claim. The factual analysis would examine the material composition and construction of the accused end caps. (Compl. ¶24; ’835 Patent, col. 9:7-11).

V. Key Claim Terms for Construction

• The Term: "mechanical coupling element... configured to engage a single electro-mechanical mount for a gas-discharge lamp"
• Context and Importance: The definition of this term is critical because it links the patented invention to the pre-existing sign infrastructure it is designed to retrofit. The infringement analysis hinges on whether the accused end caps possess the specific configuration required to interface with these legacy mounts. Practitioners may focus on this term because its construction will determine whether a wide range of modern connectors fall within the claim scope or if the scope is limited to structures that closely mimic the specific legacy parts mentioned in the patent.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The specification refers generally to engaging "standard mounts" or "conventional ... sockets," which could support an argument that the term encompasses any structure that fits into common gas-discharge lamp holders. (’835 Patent, col. 2:60-64; col. 5:24-25).
  • Evidence for a Narrower Interpretation: The specification explicitly identifies a specific type of socket ("Kulka socket"), cites a patent for that socket (U.S. Pat. No. 5,122,074), and lists specific part numbers ("Part Nos. 582GDF and/or 583GDF from Voltarc Technologies"). (’835 Patent, col. 5:25-31). This may support a narrower construction limited to elements that replicate the key structural features of these specific legacy parts.

VI. Other Allegations

• Indirect Infringement: The complaint alleges induced infringement, stating that Defendant "actively advertises, instructs, and encourages users—e.g., via videos on Grimco's website" to use the accused products in an infringing manner. (Compl. ¶37). It also alleges contributory infringement, claiming the accused components are not capable of substantial non-infringing uses. (Compl. ¶38).
• Willful Infringement: Willfulness is alleged based on pre-suit knowledge. The complaint states Defendant received a letter regarding infringement on February 14, 2018, and that its counsel acknowledged receipt on February 15, 2018, more than two years before the complaint was filed. (Compl. ¶27, ¶39).

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

The primary questions presented by the complaint concern claim scope and the specific functionality of the accused products. However, the post-filing cancellation of all claims of the '835 patent is a supervening event that fundamentally alters the landscape of the dispute.

• A core question, as originally framed by the complaint, would be one of definitional scope: Does the claim term "mechanical coupling element configured to engage a single electro-mechanical mount for a gas-discharge lamp" require a structure that mimics specific legacy sockets referenced in the patent, or does it more broadly cover any end cap that fits into a standard tube lamp holder?
• A second key question would be evidentiary: What factual evidence demonstrates that the accused products, particularly their end caps, meet every limitation of the asserted claim, including being frictionally engaged and exclusively for mechanical, non-electrical support?
• Ultimately, the dispositive issue for the case is now one of viability: Given that the U.S. Patent and Trademark Office has cancelled all claims of the patent-in-suit, what legal basis, if any, remains for the Plaintiff's infringement action to proceed? The court's first determination will likely be on the legal effect of the IPR certificate on the pending litigation.