Bishop Display Tech LLC v. LG Electronics Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Bishop Display Tech LLC (Texas)
  • Defendant: LG Electronics Inc. (Korea); LG Electronics U.S.A., Inc. (Delaware); LG Display Co., Ltd. (Korea); and New Optics, Ltd. (Korea)
  • Plaintiff’s Counsel: Nelson Bumgardner Conroy PC
• Case Identification: 2:24-cv-00085, E.D. Tex., 02/08/2024
• Venue Allegations: Plaintiff alleges venue is proper for the foreign defendants as they may be sued in any judicial district. For defendant LG Electronics U.S.A., Inc., venue is alleged based on its regular and established places of business within the Eastern District of Texas.
• Core Dispute: Plaintiff alleges that Defendants’ display products (e.g., TVs, monitors) and their component liquid crystal display modules and power supply boards infringe six patents related to LCD panel construction and power-driving circuitry.
• Technical Context: The technologies at issue relate to the physical construction of liquid crystal display (LCD) panels to improve performance by managing light leakage and the electronic circuitry used to drive display backlights.
• Key Procedural History: The complaint alleges that various Defendants had pre-suit knowledge of several patents-in-suit based on notice letters sent on behalf of prior patent owners, with the earliest notice dating to February 2017. These allegations form the basis for claims of willful infringement for five of the six asserted patents.

Case Timeline

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

U.S. Patent No. 6,819,377 - "Liquid Crystal Display Device," issued November 16, 2004

The Invention Explained

• Problem Addressed: The patent describes that as electronic devices became smaller, display manufacturers shifted to using "bare chip" liquid crystal drivers that are not housed in a protective package. These bare chips are susceptible to influence from external or reflected light, which can cause photoelectric effects and lead to "erroneous display" (ʼ377 Patent, col. 1:21–41).
• The Patented Solution: The invention proposes to shield the bare-chip driver from this unwanted light. The solution involves placing a "light shielding material" adjacent to the driver to prevent external light from reaching it. One embodiment describes this as a "light shielding film" affixed to the top surface of the display panel in the area opposite the driver's mounting position (’377 Patent, col. 2:6–12, Fig. 2). This prevents light from passing through the front of the display to interfere with the driver mounted on the panel's substrate.
• Technical Importance: This approach aimed to improve display reliability in thin-profile devices by mitigating a known failure mode for bare-chip drivers without resorting to bulky packaging that would hinder miniaturization (ʼ377 Patent, col. 1:39–41).

Key Claims at a Glance

• The complaint asserts independent claim 1 (Compl. ¶56).
• Essential elements of claim 1 include:
  • A liquid crystal panel comprising liquid crystal cells, a first plate on a displaying side, and a second plate on a reverse side.
  • A liquid crystal driver electrically connected to the panel through a circuit pattern.
  • A light shielding material disposed adjacent to the driver to prevent outer light from being incident to it.
  • A film carrier with the circuit pattern formed on a resin film.
  • The driver is mounted on the panel by a light shielding resin, which covers one end of the film carrier and a side surface of the driver.
• The complaint does not explicitly reserve the right to assert dependent claims for this patent.

U.S. Patent No. 6,822,706 - "Liquid Crystal Display Device," issued November 23, 2004

The Invention Explained

• Problem Addressed: Arising from the same specification as the ’377 patent, this patent addresses the same technical problem: preventing external and internally reflected light from causing photoelectric effects in un-packaged, bare-chip liquid crystal drivers, which could lead to display errors (ʼ706 Patent, col. 1:21–41).
• The Patented Solution: The solution involves a multi-faceted approach to light shielding. The abstract and claims describe using both a first light shielding material adjacent to one face of the driver and a second light shielding material adjacent to an opposite face of the driver. This is combined with a diffusion sheet placed behind the panel that has a "light absorbing area" on its outer periphery to absorb extraneous light that might otherwise reflect onto the driver from behind (’706 Patent, Abstract; col. 2:13-22).
• Technical Importance: This method provides a more comprehensive light-shielding solution by addressing potential light paths from both the front and back of the display assembly, enhancing the reliability of displays that use bare-chip drivers (ʼ706 Patent, col. 1:42–47).

Key Claims at a Glance

• The complaint asserts independent claim 1 (Compl. ¶73).
• Essential elements of claim 1 include:
  • A liquid crystal panel with cells between a first (displaying side) and second (reverse side) plate.
  • A liquid crystal driver connected to the panel via a circuit pattern.
  • A first light shielding material adjacent to a face of the driver to prevent outer light incidence.
  • A second light shielding material adjacent to an opposite face of the driver to prevent outer light incidence.
  • A diffusion sheet adjacent to the panel, comprising a light diffusing area and a light absorbing area on its periphery.
• The complaint does not explicitly reserve the right to assert dependent claims for this patent.

U.S. Patent No. 7,583,347 - "Liquid Crystal Display Having Electrodes Constituted by a Transparent Electric Conductor," issued September 1, 2009

• Technology Synopsis: This patent addresses the trade-off between electrode structure and display brightness in certain types of LCDs. The invention describes forming at least one of the common and pixel electrodes with both a wiring portion and an electrode portion, where the electrode portion is at least partially made of a transparent conductor (like ITO) and is formed in a different layer from the main scanning signal lines (’347 Patent, Abstract). This configuration aims to increase the light-transmitting area of a pixel, thereby improving luminance, while managing the electrical connections and preventing short-circuits.
• Asserted Claims: Independent claim 1 is asserted (Compl. ¶95).
• Accused Features: The complaint accuses the fundamental structure of the accused LCD panels, alleging they contain an array substrate with common and pixel electrodes, an opposing substrate, and a liquid crystal layer configured as claimed (Compl. ¶¶96-100).

U.S. Patent No. 7,995,047 - "Current Driving Device," issued August 9, 2011

• Technology Synopsis: This patent relates to the driver circuitry that supplies power to displays. The invention is a current driving device that operates in three distinct modes: a "voltage supply mode," a "current supply mode," and a "current output mode." This multi-mode operation allows the device to first use a stable voltage to quickly pre-charge its internal circuits to a near-correct level, and then use a reference current for fine-tuned calibration, enabling faster and more accurate calibration before driving the load (’047 Patent, Abstract).
• Asserted Claims: Independent claim 1 is asserted (Compl. ¶116).
• Accused Features: The complaint accuses the LG power supply board (model LM93A EAX68464307) and the MP3378R chipset it contains, which is used in products like the LG 38GL950G monitor. The allegations map the functions of the chipset to the claimed three-mode operation (Compl. ¶¶116, 120, 123).

U.S. Patent No. 8,093,830 - "Semiconductor Light Source Driving Apparatus and Semiconductor Light Source Driving Method," issued January 10, 2012

• Technology Synopsis: This patent addresses the challenge of stably driving semiconductor light sources like LEDs, whose electrical characteristics (impedance) can change significantly with the drive current. The invention is a driving apparatus that includes an "impedance detecting section" that detects the impedance of the light source. The output of this impedance detection is used by an "output voltage controlling section" to adjust the drive voltage, creating a control loop that adapts to the light source's changing characteristics to maintain stable performance (’830 Patent, Abstract).
• Asserted Claims: Independent claim 1 is asserted (Compl. ¶141).
• Accused Features: The complaint accuses the same LG power supply board (LM93A EAX68464307) and monitor (LG 38GL950G), alleging its circuitry, including the MP3378R chipset, performs impedance detection and controls the output voltage based on this detection as claimed (Compl. ¶¶141, 148, 149).

U.S. Patent No. 7,414,682 - "Liquid Crystal Display Unit and Production Method Thereof," issued August 19, 2008

• Technology Synopsis: This patent describes a technique for improving both luminance and contrast in LCDs, particularly those using transversal electric fields (like IPS-mode displays). The invention involves constructing pixel structures (such as signal lines or electrodes) from both a "light-transmitting" portion and a "light-non-transmitting" portion. By making certain parts of the pixel transparent, more light from the backlight can pass through, increasing brightness. By making other parts, particularly those in low-contrast areas, non-transmitting (and often reflective), the average contrast of the display is improved (’682 Patent, Abstract).
• Asserted Claims: Independent claim 7 is asserted (Compl. ¶165).
• Accused Features: The complaint accuses the structure of the accused LCD panels, specifically alleging that at least one of the electrodes is constituted by both a light-transmitting conductive layer and a light-non-transmitting conductive layer (Compl. ¶170).

III. The Accused Instrumentality

Product Identification

• The complaint identifies several categories of accused products: (1) TFT-LCDs or Liquid Crystal Modules (LCMs) manufactured by LGD and New Optics; (2) end-user products manufactured by LGE and LGEUS, such as TVs, monitors, laptops, tablets, and mobile phones, which incorporate these components; and (3) power supply boards for display products (Compl. ¶6).

Functionality and Market Context

• The complaint provides specific product examples for its allegations. For the display panel patents, it identifies the LGD panel model LM270QQ1(SD)(D1) (used in the Apple iMac Pro), the LG TV model 49SM8600PUA, and the LG TV model 55UM7300PUA as representative accused products (Compl. ¶¶56, 73). For the power circuitry patents, it identifies the LG 38GL950G monitor and its internal power supply board, model LM93A EAX68464307, which contains an MP3378R chipset (Compl. ¶¶116, 120, 141).
• The complaint's visual evidence consists of photographs from teardowns of these products. For instance, a labeled photograph of an LGD display module shows the location of the liquid crystal drivers and circuit pattern (Compl. ¶58). These visuals are used to map the physical components of the accused products to the elements of the asserted patent claims.
• The complaint alleges these products are part of a global supply chain where LGD and New Optics manufacture infringing components that are incorporated into products sold in the U.S. by LGE and LGEUS through retailers like Best Buy (Compl. ¶40).

IV. Analysis of Infringement Allegations

• ’377 Patent Infringement Allegations

• Identified Points of Contention:

  • Scope Questions: A central question may be the interpretation of "light shielding resin." The claim requires this resin to perform the mounting function while also covering specific parts of the film carrier and driver. The litigation may focus on whether the material used in the accused products, often a general-purpose encapsulant or adhesive, meets the specific structural and functional requirements of a "light shielding resin" as claimed.
  • Technical Questions: The complaint alleges infringement based on visual inspection of teardowns. A technical question will be whether the material identified as "light shielding material" in paragraph 59 actually functions to "prevent an outer light from being incident" to the driver to a degree contemplated by the patent, or if its light-blocking properties are merely incidental to its primary function as an encapsulant.

• ’706 Patent Infringement Allegations

• Identified Points of Contention:
  • Scope Questions: The claim requires distinct "first" and "second" light shielding materials on "opposite" faces of the driver. A likely point of contention will be whether the accused products actually contain two separate materials or a single encapsulant that covers multiple faces, raising the question of whether a single material can satisfy both limitations.
  • Technical Questions: Evidentiary questions may arise regarding the function of the "light absorbing area" on the diffusion sheet. The complaint alleges its purpose is to absorb extraneous light incident on the driver (Compl. ¶79). The defense may argue this area serves other purposes (e.g., as a bezel or frame) and that any light absorption relevant to the driver is incidental, not functional as required by the claim.

V. Key Claim Terms for Construction

• For the ’377 Patent:

  • The Term: "light shielding resin"
  • Context and Importance: This term appears in the final "wherein" clause of claim 1, which requires the driver to be mounted by this specific type of resin. The construction of this term is critical because it links the structural act of mounting the driver to the functional property of light shielding. Practitioners may focus on this term because if the material used for mounting is not a "light shielding resin," the claim may not be infringed.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification describes using "Silicon resin as a light shielding resin" to protect an electrode and notes it is "colored in black in order to enhance the light shielding effect" (’377 Patent, col. 6:30–35). This could suggest that the core identity is the resin, and the light-shielding property can be an enhanced feature, not necessarily an inherent, defining one.
    • Evidence for a Narrower Interpretation: The same passage explicitly states the resin is colored black "to enhance the light shielding effect," and the patent's overall purpose is to solve the problem of light-induced errors. This may support an argument that to qualify, the resin must be specifically chosen or modified for its light-shielding properties, not just be an incidentally opaque adhesive.

• For the ’706 Patent:

  • The Term: "a second light shielding material disposed adjacent an opposite face of said liquid crystal driver"
  • Context and Importance: This limitation is a key differentiator of claim 1, requiring a second, distinct shielding element. The viability of the infringement allegation hinges on whether the accused products contain a structure that meets this "second material on an opposite face" requirement.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification discloses multiple embodiments. For example, the embodiment in FIG. 4 shows a light shielding resin 110 covering one face and a light shielding tape 109 on the opposite face, suggesting two distinct materials (’706 Patent, col. 6:40–46). An argument could be made that any configuration providing shielding on two opposite sides, even if part of a single contiguous application of material, meets the spirit of the invention.
    • Evidence for a Narrower Interpretation: The use of "a second light shielding material" distinct from "a first light shielding material" in the claim language implies two structurally separate components. The clear depiction of two different components (resin 110, tape 109) in FIG. 4 could be used to argue that the claim requires two non-identical, separately applied materials on opposing faces.

VI. Other Allegations

• Indirect Infringement: For the ’706, ’347, ’047, ’830, and ’682 patents, the complaint alleges that Defendants actively induced infringement by, among other things, creating and maintaining distribution channels for the accused products in the U.S., providing instruction manuals, and marking products with UL Solutions labels indicating compliance with U.S. laws, thereby encouraging their sale and use (Compl. ¶¶ 81, 103, 128, 151, 174).
• Willful Infringement: For the same five patents, the complaint alleges willful infringement. The allegations are based on pre-suit knowledge stemming from notice letters sent to LGD, LGE, and New Optics on various dates, with the earliest alleged notice occurring on February 8, 2017 (Compl. ¶¶ 80, 83, 101-102, 105, 127, 130, 150, 153, 172-173, 176). For the ’682 patent, knowledge is also alleged based on Defendants' prosecution of their own patents, which purportedly cited the ’682 patent (Compl. ¶172).

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

• A core issue will be one of structural correspondence: do the highly integrated components of modern LCD modules, as depicted in the complaint’s teardown photographs, contain the distinct, multi-part structures required by the asserted claims? For example, can a single application of encapsulant simultaneously meet the claim limitations for a "first light shielding material" on one face and a "second light shielding material" on an "opposite face"?
• A second central question will be one of functional specificity: do the accused power supply board chipsets perform the specific multi-step calibration logic of the ’047 patent or the explicit impedance-based feedback control of the ’830 patent? The case may turn on whether the general operations of the accused circuits map directly onto the precise functions recited in the claims, or if there is a fundamental mismatch in their method of operation.
• A key legal question will concern imputation of knowledge: can the alleged notice of infringement provided to one corporate entity (e.g., LGD in Korea) serve as the legal basis for willful infringement by related entities (e.g., LGEUS) and commercial partners (e.g., New Optics)? The resolution will likely depend on the court's analysis of the plaintiff's agency and alter-ego allegations.