DCT

2:25-cv-00312

Light Guide Innovations LLC v. Walmart Inc

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Key Events
Amended Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:25-cv-00312, E.D. Tex., 09/12/2025
  • Venue Allegations: Plaintiff alleges venue is proper because Defendants are foreign companies that may be sued in any judicial district. It further alleges Defendants are subject to personal jurisdiction and have committed acts of patent infringement in the Eastern District of Texas, and have previously submitted to the court's jurisdiction in other patent cases.
  • Core Dispute: Plaintiff alleges that Defendant’s televisions and display products infringe a portfolio of sixteen U.S. patents related to LED backlight technology, including light source construction, lens design, and photoluminescent materials.
  • Technical Context: The patents-in-suit relate to the design and construction of LED backlight units, a core technology for illuminating the liquid crystal displays (LCDs) used in the vast majority of modern televisions and monitors.
  • Key Procedural History: The complaint notes that Hisense has previously submitted to the jurisdiction of the Eastern District of Texas in other patent litigation involving video display technology. To support allegations of willfulness, the complaint alleges Hisense has known of the asserted patents at least since the time they were widely publicized during and after their sale from LG Innotek to Suzhou Lekin Semiconductor.

Case Timeline

Date Event
2006-03-15 Earliest Priority Date for ’411 and ’352 Patents
2006-08-24 Earliest Priority Date for ’415 Patent
2006-12-29 Earliest Priority Date for ’537 Patent
2007-11-06 Earliest Priority Date for ’380 Patent
2009-02-17 Earliest Priority Date for ’778 Patent
2009-05-13 Earliest Priority Date for ’200 Patent
2009-11-20 Earliest Priority Date for multiple patents (’122, ’307, ’729, ’093, ’744, ’048, ’183, ’378, ’823)
2011-04-12 ’380 Patent Issued
2011-05-03 ’415 Patent Issued
2011-11-08 ’307 Patent Issued
2012-07-03 ’093 Patent Issued
2012-08-07 ’352 Patent Issued
2012-09-18 ’537 Patent Issued
2013-03-12 ’183 Patent Issued
2013-04-02 ’778 Patent Issued
2013-08-13 ’122 Patent Issued
2013-10-22 ’200 Patent Issued
2013-12-31 ’729 Patent Issued
2014-05-13 ’411 Patent Issued
2014-09-02 ’048 Patent Issued
2017-01-03 ’744 Patent Issued
2017-05-02 ’378 Patent Issued
2018-07-24 ’823 Patent Issued
2019-01-01 Alleged Start of Infringing Importation (approx.)
2025-09-12 Complaint Filed

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

U.S. Patent No. 7,936,415 - "Light Source Apparatus And Liquid Crystal Display Having The Same"

  • Patent Identification: U.S. Patent No. 7,936,415, "Light Source Apparatus And Liquid Crystal Display Having The Same," issued May 3, 2011.

The Invention Explained

  • Problem Addressed: The patent background identifies a need to improve the mechanical and electrical connection structure for the multiple LED module substrates used in a display backlight. (’415 Patent, col. 1:26-31).
  • The Patented Solution: The invention proposes a system where separate LED module substrates are connected in series using "connecting substrates." A special "termination connecting substrate" is used at the end of the final module to create a closed-loop circuit, which aims to enhance electrical reliability and mechanical strength between the modules. (’415 Patent, col. 2:36-41; Fig. 8).
  • Technical Importance: This design sought to simplify the assembly of large LED arrays for backlights and improve their robustness by using dedicated connectors rather than requiring a single, large, and complex substrate. (’415 Patent, col. 2:1-5).

Key Claims at a Glance

  • The complaint asserts at least independent claim 1. (Compl. ¶65).
  • Essential elements of claim 1 include:
    • at least one module substrate comprising connecting terminals at both side ends thereof;
    • a light emitting diode on the module substrate; and
    • a plurality of connecting substrates connected to the connecting terminals of the module substrate, wherein the connecting substrate comprises a termination connecting substrate, by which the connecting terminal provided at one end of a final module substrate of the module substrates is prepared as a closed loop circuit. (’415 Patent, col. 7:2-12).
  • The complaint does not explicitly reserve the right to assert dependent claims for this patent.

U.S. Patent No. 7,922,380 - "Light Unit And Display Device Having The Same"

  • Patent Identification: U.S. Patent No. 7,922,380, "Light Unit And Display Device Having The Same," issued April 12, 2011.

The Invention Explained

  • Problem Addressed: The patent background describes a need for light-emitting modules with improved heat conduction properties for use in display devices. (’380 Patent, col. 1:31-35).
  • The Patented Solution: The invention discloses a light unit with a specific layered structure designed to dissipate heat. It uses a flexible printed circuit board (PCB) with LEDs mounted on it. A metal plate is attached to the rear of this flexible board, and this metal plate in turn is contacted with the bottom surface of the main housing, creating an efficient thermal pathway away from the LEDs. (’380 Patent, col. 2:60-col. 3:4; Fig. 1). The flexible nature of the PCB allows it to be bent into position. (’380 Patent, col. 2:60-63).
  • Technical Importance: By creating a direct thermal path from the back of the LED board to the main chassis, this design aimed to improve thermal management, enhancing the longevity and performance of the LEDs in a backlight unit. (’380 Patent, col. 4:10-12).

Key Claims at a Glance

  • The complaint asserts at least independent claim 1. (Compl. ¶78).
  • Essential elements of claim 1 include:
    • a light guide member outputting surface light upward;
    • a board disposed to a first side of the light guide member;
    • a plurality of light-emitting devices mounted on a first side of the board;
    • a reflection sheet under the light guide member;
    • a housing receiving the light guide member, the light-emitting devices, the board, and the reflection sheet; and
    • a metal plate attached to a second side of the board and a first side of the housing, wherein...the board is a flexible PCB that includes a first portion and a second portion with specific spatial arrangements relative to the other components. (’380 Patent, col. 5:47-col. 6:23).
  • The complaint does not explicitly reserve the right to assert dependent claims for this patent.

Multi-Patent Capsules

  • U.S. Patent No. 8,562,200, "Lighting Module, Backlight Unit, And Display Device Including The Same," issued October 22, 2013.

    • Technology Synopsis: The patent relates to an LED backlight unit providing reliable lighting for displays. (Compl. ¶44). The technology involves a lighting module with a substrate, LEDs, and at least one "guide protrusion" on the surface of the substrate to aid in assembly or alignment. (Compl. ¶99).
    • Asserted Claims: At least independent claim 1. (Compl. ¶99).
    • Accused Features: The accused features are the LED strips (substrate) in Hisense televisions, the LEDs mounted on them, and circular protrusions on the LED strip that are alleged to be the claimed "guide protrusion." (Compl. ¶¶100-103).

  • U.S. Patent No. 8,506,122, "Lens And Light Emitting Apparatus Having The Same," issued August 13, 2013.

    • Technology Synopsis: The patent relates to a light emitting apparatus with a lens having "superior light emitting characteristics in a lateral direction." (Compl. ¶48). The claimed lens has a specific geometry, including recesses on its top and bottom surfaces and a support structure. (Compl. ¶113).
    • Asserted Claims: At least independent claim 1. (Compl. ¶113).
    • Accused Features: The complaint alleges that the optics (lenses) placed over the individual LEDs in Hisense TV backlights have the claimed structure, including top and bottom recesses. (Compl. ¶¶114-117).

  • U.S. Patent No. 8,052,307, "Lens And Light Emitting Apparatus Having The Same," issued November 8, 2011.

    • Technology Synopsis: This patent is related to the ’122 Patent and also concerns a light emitting apparatus with a specific lens geometry designed for particular light distribution. (Compl. ¶48). The claims recite a light emitting device package that includes a package body, a phosphor layer, and a sealing resin layer, in addition to the lens with top and bottom recesses. (Compl. ¶127).
    • Asserted Claims: At least independent claim 1. (Compl. ¶127).
    • Accused Features: The accused features are the LED packages on the LED strips of Hisense TVs, which are alleged to include a package body, a yellow phosphor layer, a resin layer, and an overlying lens with the claimed recess geometry. (Compl. ¶¶128-131).

The complaint asserts eleven additional patents: U.S. Patent Nos. 8,616,729; 8,213,093; 9,534,744; 8,823,048; 8,395,183; 9,638,378; 10,030,823; 8,408,778; 8,267,537; 8,723,411; and 8,237,352. The allegations for these patents generally relate to specific lens geometries and dimensions, photoluminescent sheets (including quantum dot technology), and methods of attaching light units to a chassis. (Compl. ¶¶45-49, 137-304).

III. The Accused Instrumentality

Product Identification

  • The complaint accuses a wide range of Hisense televisions and displays, including all versions and variants of LED, 4K UHD, QLED, Mini LED QLED, and ULED models. (Compl. ¶50). Specific models identified as examples include the 50R6E3, 50U6H, 65U6HF, 50K, and 75QD7N. (Compl. ¶¶64, 77, 126, 265, 279).

Functionality and Market Context

  • The accused instrumentalities are televisions that utilize LED backlights to illuminate their display panels. (Compl. ¶50). The allegations focus on the internal construction of these backlight units, including the LED strips, the lenses covering individual LEDs, the electrical connections between strips, and the overall mechanical assembly within the television chassis. (Compl. ¶¶66-68, 79-89). The complaint alleges that Hisense is a "leading manufacturer and seller of displays and televisions" and aims to become the "#1 seller of television sets in the U.S." (Compl. ¶¶2, 55).

IV. Analysis of Infringement Allegations

U.S. Patent No. 7,936,415 Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
at least one module substrate comprising connecting terminals at both side ends thereof The accused TVs contain multiple LED strips, which are alleged to be the "module substrate," and these strips have connecting terminals at both ends. ¶66 col. 7:2-4
a light emitting diode on the module substrate The LED strips in the accused products include multiple LED lights, alleged to be the "light emitting diode." ¶67 col. 7:5-5
a plurality of connecting substrates connected to the connecting terminals of the module substrate The accused TVs use connecting substrates with terminals to connect one LED strip to another. ¶68 col. 7:6-8
wherein the connecting substrate comprises a termination connecting substrate, by which the connecting terminal provided at one end of a final module substrate of the module substrates is prepared as a closed loop circuit The series of connected LED strips allegedly forms a closed loop circuit, with the final connection acting as the "termination connecting substrate." The image provided shows the terminal end of a substrate. ¶68 col. 7:9-12
  • Identified Points of Contention:
    • Scope Questions: A central question may be whether the standard wire harnesses or small PCBs used to link commercial LED strips meet the definition of "connecting substrates" and "termination connecting substrate" as described in the patent. The defense may argue these are generic electrical connectors, not the specific structures contemplated by the invention.
    • Technical Questions: The complaint alleges the connection scheme creates a "closed loop circuit." (Compl. ¶68). The nature of this "closed loop" may be a point of dispute—whether it refers to a simple electrical series circuit, which is conventional, or a specific physical and mechanical loop structure enabled by the claimed "termination connecting substrate" as depicted in the patent's figures. (e.g., ’415 Patent, Fig. 8).

U.S. Patent No. 7,922,380 Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a light guide member outputting surface light upward Each LED in the backlight includes a transparent glass cover or lens over the top to guide light upward, which is alleged to be the "light guide member." ¶79 col. 5:48-49
a board disposed to a first side of the light guide member The accused products include LED strips, which are alleged to be the "board," disposed alongside the light guide members. ¶80 col. 5:50-51
a plurality of light-emitting devices mounted on a first side of the board The LED strips contain multiple LEDs mounted on their front surface. ¶81 col. 5:52-53
a reflection sheet under the light guide member A reflection sheet is placed under the array of LEDs and their associated light guide members. ¶82 col. 5:54-54
a housing receiving the light guide member, the light-emitting devices, the board, and the reflection sheet The exterior black covering and frame of the TV is alleged to be the "housing" that contains the internal backlight components. ¶84 col. 5:55-57
a metal plate attached to a second side of the board and a first side of the housing... wherein the board is a flexible PCB that includes a first portion... and a second portion... The accused TVs allegedly include a metal plate that supports the LED strips and is attached to the housing. The complaint asserts the LED strip board acts as a "flexible PCB" with different portions. Teardown images show the metal plate and housing. ¶¶85-88 col. 5:58-col. 6:20
  • Identified Points of Contention:
    • Scope Questions: The claim requires a "light guide member." The complaint identifies the individual lens over each LED as this member. (Compl. ¶79). It may be argued that in the context of the art, a "light guide member" or "light guide plate" typically refers to a large, flat panel that distributes light from edge-mounted LEDs, not an individual lens in a direct-lit array.
    • Technical Questions: The claim explicitly requires the "board" to be a "flexible PCB." (’380 Patent, col. 6:13). The complaint's photographic evidence depicts LED strips mounted on what appear to be rigid metal or composite substrates. (Compl. p. 30). This raises the question of whether the accused LED strips meet the "flexible PCB" limitation, which the patent specification links to the ability to be "bent at a predetermined angle." (’380 Patent, col. 2:60-63).

V. Key Claim Terms for Construction

For the ’415 Patent:

  • The Term: "closed loop circuit"
  • Context and Importance: This term is the central feature of independent claim 1. Its construction will determine whether a standard series connection of LED strips, as is common in backlight manufacturing, falls within the scope of the claim, or if a more specific physical arrangement is required.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The plain meaning of the term could be argued to cover any electrical circuit that is closed. The patent states the purpose is to enhance "electrical reliability." (’415 Patent, col. 2:2-3).
    • Evidence for a Narrower Interpretation: The claim states the closed loop is prepared "by which" the "termination connecting substrate." This suggests the "termination connecting substrate" itself is what creates the loop. Figure 8 in the patent shows a specific substrate (145) with internal traces (146C, 147C) that physically loop connections back, which may support a narrower construction requiring a specific component rather than just a final wire connection. (’415 Patent, Fig. 8; col. 5:29-41).

For the ’380 Patent:

  • The Term: "flexible PCB"
  • Context and Importance: This term defines the nature of the "board" carrying the LEDs and is a critical limitation of claim 1. Given that many LED backlights are built on rigid substrates, whether the accused products' boards are "flexible" will likely be a core infringement question. Practitioners may focus on this term because the complaint's visual evidence does not appear to show a board that is bent or inherently flexible.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The patent does not provide an explicit definition of "flexible." A party might argue that any non-brittle substrate that has some minimal degree of flex could qualify.
    • Evidence for a Narrower Interpretation: The specification explicitly links the term to a functional purpose: the board "may be divided into an upper portion 154A and a lower portion 154B which are bent at a predetermined angle." (’380 Patent, col. 2:60-63). This suggests the flexibility must be sufficient to allow for such bending, potentially limiting the term to materials that can be creased or sharply bent, rather than boards that are merely not perfectly rigid.

VI. Other Allegations

  • Indirect Infringement: For each asserted patent, the complaint alleges induced infringement under 35 U.S.C. § 271(b). The allegations state that Hisense induces its customers and end-users to infringe by "manufacturing, selling, distributing, and/or otherwise making available the Accused Products, and providing instructions, documentation, and other information" such as technical support, product manuals, and advertisements. (Compl. ¶¶69, 90). Contributory infringement is also alleged. (Compl. ¶¶70, 91).
  • Willful Infringement: The complaint alleges that Hisense's infringement has been and continues to be willful. The basis for this allegation is that Hisense allegedly has known of the Plaintiff's patents "at least since they were widely publicized during and after LG Innotek’s sale to Suzhou Lekin Semiconductor." (Compl. ¶¶71, 92). This alleges pre-suit knowledge of the patent portfolio from which the patents-in-suit originate.

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

This dispute involves a large patent portfolio covering fundamental aspects of modern LED backlight design. The initial proceedings will likely focus on narrowing the number of asserted claims and patents. Based on the lead patents analyzed, the case raises several key questions for the court:

  • A central issue will be one of definitional scope: can the term "flexible PCB," as used in the ’380 Patent in the context of a board that is "bent at a predetermined angle," be construed to read on the seemingly rigid LED circuit board strips used in the accused televisions?
  • A second core issue will be one of structural correspondence: do the common electrical connectors used to link LED strips in the accused products constitute the specific "connecting substrates" and "termination connecting substrate" required to form the "closed loop circuit" of the ’415 Patent, or is there a material difference between a generic series circuit and the claimed invention?
  • An early evidentiary question will concern knowledge and willfulness: what specific evidence demonstrates that the alleged publicity surrounding the LG Innotek patent portfolio sale put Hisense on notice of the particular patents-in-suit, sufficient to support a claim of willful infringement?