DCT

2:25-cv-00358

Longitude Licensing Ltd v. BOE Technology Group Co Ltd

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:25-cv-00358, E.D. Tex., 04/08/2025
  • Venue Allegations: Venue is asserted under 28 U.S.C. § 1391(c)(3), which provides that a non-U.S. resident may be sued in any judicial district, as all defendants are organized under the laws of the P.R. China.
  • Core Dispute: Plaintiffs allege that Defendants’ liquid crystal display (LCD) panels and modules, and the consumer televisions that incorporate them, infringe three patents related to LCD panel design, testing, and connectivity.
  • Technical Context: The technology at issue involves foundational methods for manufacturing modern LCD panels, focusing on optimizing terminal configurations for signal integrity, incorporating on-substrate inspection features, and structuring wiring for reliable connectivity.
  • Key Procedural History: The complaint alleges a history of licensing negotiations between Plaintiffs and Defendant BOE beginning around January 2020, during which Plaintiffs allegedly provided actual notice and claim charts for the ’146 and ’512 patents. These allegations form the basis for claims of willful infringement against BOE.

Case Timeline

Date Event
2003-08-08 ’146 Patent Priority Date
2009-03-23 ’512 Patent Priority Date
2009-12-03 ’020 Patent Priority Date
2009-12-22 ’146 Patent Issue Date
2012-11-27 ’512 Patent Issue Date
2013-03-05 ’020 Patent Issue Date
2020-01-02 Licensing negotiations allegedly began with BOE
2021-04-08 Actual notice of ’512 patent allegedly provided to BOE
2025-04-08 Complaint Filing Date

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

U.S. Patent No. 7,636,146 - “Electro-Optical Panel, System with Terminals Having Different Corresponding Characteristics,” issued December 22, 2009

The Invention Explained

  • Problem Addressed: The patent describes a problem in designing electro-optical panels where a large number of input terminals must fit into a limited area. Making terminals smaller to save space increases their contact resistance, which can degrade or "dull" high-frequency driving signals, impairing display performance (’146 Patent, col. 2:3-14).
  • The Patented Solution: The invention proposes optimizing the terminal layout by varying terminal sizes based on the signal type. Input terminals for signals with a higher frequency component (e.g., driving signals) are designed with a larger area to minimize contact resistance and ensure signal integrity. Conversely, terminals for signals with lower frequency components (e.g., image signals) can be made smaller to conserve space (’146 Patent, Abstract; col. 2:30-35).
  • Technical Importance: This design allows for higher-density terminal connections on display panels—critical for high-resolution displays—without compromising the quality of essential high-frequency signals needed for proper operation (’146 Patent, col. 2:50-58).

Key Claims at a Glance

  • The complaint asserts claims 10-23, with infringement allegations detailed for independent claim 23 (Compl. ¶71-72).
  • The essential elements of independent claim 23 include:
    • A substrate with data lines, scanning lines, and pixels implemented thereon.
    • A clock signal input terminal and an image signal input terminal, both implemented on the substrate.
    • A scanning line drive circuit on the substrate.
    • A mounting member (e.g., a flexible cable) that is distinct from the substrate.
    • The mounting member comprises a first wiring connected to the clock signal input terminal and a second wiring connected to the image signal input terminal.
    • The clock signal input terminal overlaps the first wiring by a larger area than the area at which the image signal input terminal overlaps the second wiring.
  • The complaint reserves the right to assert additional claims (Compl. ¶72).

U.S. Patent No. 8,319,512 - “Flexible Substrate Including Inspection Electrode for Outputting Signal Processed in Integrated Circuit, Electro-Optical Device, and Electronic Device,” issued November 27, 2012

The Invention Explained

  • Problem Addressed: In complex electronic devices, it can be difficult to monitor or test signals that are processed internally within an integrated circuit (IC) on a flexible substrate, particularly if those signals are not output to external connections. Adding dedicated terminals for testing complicates the design and increases the connection count (’512 Patent, col. 1:26-39).
  • The Patented Solution: The invention places a dedicated "inspection electrode" on the flexible substrate that is electrically connected to the internal workings of the IC. This allows a test probe to access and monitor internal signals during manufacturing or diagnostics without requiring a permanent output pin, thereby streamlining testing and quality control (’512 Patent, Abstract; col. 2:5-25). The invention also includes a switching section to turn the output to this inspection electrode on or off.
  • Technical Importance: This approach improves manufacturability by enabling efficient real-time signal assessment and defect detection for ICs on flexible substrates, leading to higher-quality and more reliable electronic devices (’512 Patent, col. 2:40-42).

Key Claims at a Glance

  • The complaint asserts claims 1 and 3-9, with infringement allegations detailed for independent claim 1 (Compl. ¶103-104).
  • The essential elements of independent claim 1 include:
    • A flexible substrate comprising a substrate body, lines, and connection terminals.
    • An integrated circuit (IC) arranged on the substrate body.
    • An inspection electrode arranged on the substrate body, electrically connected to the IC and capable of outputting a signal processed in the IC.
    • A switching section that switches an operation of the inspection electrode on/off to cause it to output or not output the processed signal.
  • The complaint reserves the right to assert additional claims (Compl. ¶104).

Multi-Patent Capsule: U.S. Patent No. 8,391,020

  • Patent Identification: U.S. Patent No. 8,391,020, “Electro-Optical Device, Electro-Optical Panel, and Electronic Apparatus,” issued March 5, 2013 (Compl. ¶25).
  • Technology Synopsis: The patent addresses enhancing electrical connectivity and reliability between a display panel and external circuit substrates. The invention achieves this through an optimized terminal and wiring configuration, where specific terminals in separate groups are electrically connected by dedicated wiring that runs on the electro-optical panel, ensuring stable signal transmission and reducing degradation (Compl. ¶25; ’020 Patent, Abstract).
  • Asserted Claims: The complaint asserts claims 1-2 and 11-13, focusing on independent claim 1 (Compl. ¶135-136).
  • Accused Features: The accused features are the terminal portions and connection wiring on the BOE LCD panels. Specifically, the complaint alleges that a first terminal and a fourth terminal (in different terminal groups) are electrically connected by a first connection wiring, and a second terminal and a third terminal are connected by a second connection wiring, with the wiring provided on the panel itself (Compl. ¶141-144).

III. The Accused Instrumentality

Product Identification

The complaint identifies two classes of accused products:

  1. BOE Accused Instrumentalities: LCD panels and modules designed, manufactured, and sold by Defendant BOE (Compl. ¶41).
  2. Hisense Accused Instrumentalities: Finished consumer products, such as televisions, that incorporate the infringing BOE LCD panels and modules. Exemplary products identified include the Hisense 43” FHD TV (model 43A45H) and the Hisense 75” 4K TV (model 75R6E) (Compl. ¶45, 72, 104).

Functionality and Market Context

  • The relevant functionality resides in the physical architecture of the LCD panels manufactured by BOE. The complaint alleges these panels contain the specific substrate layouts, terminal configurations, wiring structures, and flexible substrate designs claimed by the patents-in-suit (Compl. ¶75-88, 107-119). The complaint includes a photograph of a printed circuit board on a Hisense TV that bears a "BOE" logo to link the accused end-product to the accused component manufacturer (Compl. ¶74).
  • The complaint alleges that BOE is a world leader in the global semiconductor display industry, ranking first in shipment volume for LCD panels across several applications, and that Hisense is a major television brand in the United States (Compl. ¶17, 30).

IV. Analysis of Infringement Allegations

’146 Patent Infringement Allegations

Claim Element (from Independent Claim 23) Alleged Infringing Functionality Complaint Citation Patent Citation
a substrate; The BOE LCD panel comprises an array substrate. ¶75 col. 6:49-51
data lines; ... scanning lines intersecting the data lines; ... pixels disposed corresponding to intersections... The array substrate includes vertically oriented data lines, horizontally oriented scanning lines that intersect the data lines, and pixels located at these intersections. ¶76-78 col. 8:20-28
a clock signal input terminal supplied with a clock signal; The array substrate comprises a clock signal input terminal that is supplied with a clock signal, which allegedly provides a signal to the scanning line driving circuitry. ¶79 col. 13:30-38
an image signal input terminal supplied with an image signal; The array substrate comprises an image signal input terminal that is supplied with an image signal, which allegedly provides a voltage corresponding to grayscale to the pixel electrodes. ¶80-81 col. 13:26-29
a mounting member that is distinct from and connected to the substrate... The BOE LCD panel includes a flexible printed circuit (FPC) that is a distinct component connected to the array substrate. The complaint provides an annotated photograph of this "Mounting member (FPC)" (Compl. ¶84). ¶84-85 col. 15:18-20
a first wiring that is connected to the clock signal input terminal; and a second wiring that is connected to the image signal input terminal... The FPC comprises a first wiring connected to the clock signal input terminal and a second wiring connected to the image signal input terminal. ¶86-87 col. 16:16-21
wherein the clock signal input terminal overlaps the first wiring of the mounting member by a larger area than an area at which at least one of the image signal input... The area where the clock signal input terminal on the substrate overlaps the first wiring on the FPC is larger than the overlap area for the image signal input terminal. An annotated image alleges this difference is at least four-fold (Compl. ¶88). ¶88 col. 16:22-26

Identified Points of Contention

  • Scope Questions: The patent distinguishes between "driving signals" with a "higher frequency component" and "image signals" (’146 Patent, col. 2:32-34). A central question will be whether the signal supplied to the accused "clock signal input terminal" meets the patent's definition of a high-frequency driving signal, thereby justifying the "larger area" feature. The complaint alleges the function of the signal but does not provide evidence of its frequency characteristics.
  • Technical Questions: The infringement allegation for the "larger area" limitation is supported by a visual comparison alleging a 4x difference in overlap size (Compl. ¶88). The factual basis for this measurement and its consistency across the full range of accused products may become a point of dispute.

’512 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a flexible substrate comprising: a substrate body; a plurality of lines ... a plurality of connection terminals... The BOE LCD panel in the accused Hisense TV includes a flexible substrate with a substrate body, lines, and connection terminals. ¶107-110 col. 8:46-54
an integrated circuit that is arranged on the substrate body... An integrated circuit (IC) is arranged on the flexible substrate body. ¶111 col. 8:55-57
an inspection electrode ... capable of outputting a signal processed in the integrated circuit... The flexible substrate includes inspection electrodes that are electrically connected to the IC and are alleged to be capable of outputting signals processed within the IC, such as signals from internal amplifiers. ¶112-115 col. 8:58-62
a switching section that switches an operation of the inspection electrode on/off to cause the inspection electrode to... The IC allegedly contains "selector circuitry" that functions as the claimed "switching section." This circuitry, based on control signals, either connects an internal amplifier output to the inspection electrode or disconnects it, thereby switching the electrode's output operation on or off. A circuit diagram illustrates this alleged function (Compl. ¶117). ¶117-119 col. 9:1-5

Identified Points of Contention

  • Scope Questions: The construction of "switching section that switches an operation of the inspection electrode on/off" will be critical. A question for the court is whether the accused "selector circuitry," which appears to be a signal router or multiplexer, performs the specific claimed function of switching the electrode's operation on/off, or if it merely performs standard signal routing that incidentally results in the electrode being disconnected in some states.
  • Technical Questions: What is the primary purpose of the accused "selector circuitry"? The patent links the switching function to power saving by enabling output only when monitoring is needed (’512 Patent, col. 3:1-4). The defense may argue the accused circuitry serves a different primary operational function, raising the question of whether its operation truly maps onto the claimed invention.

V. Key Claim Terms for Construction

For the ’146 Patent

  • The Term: "clock signal"
  • Context and Importance: This term appears in independent claim 23. The patent's core inventive concept is providing a larger terminal area for higher-frequency signals to prevent signal degradation. The infringement case hinges on classifying the signal supplied to the larger terminal in the accused device as a "clock signal" that fits the patent's description of a high-frequency "driving signal."
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The term "clock signal" is not explicitly defined with a specific frequency range. A party may argue for its plain and ordinary meaning. The specification provides "Y clock signal YCK" as an example but does not limit the term to only that signal (’146 Patent, col. 10:29-30).
    • Evidence for a Narrower Interpretation: The patent repeatedly frames the problem and solution around the distinction between signals with a "higher frequency component" (driving signals) and those with "relatively low-frequency components" (image signals) (’146 Patent, col. 2:32-34, 58-65). Practitioners may focus on this distinction, arguing that to be a "clock signal" within the meaning of the patent, a signal must be shown to possess this higher-frequency characteristic relative to the image signal to give effect to the patent's stated purpose.

For the ’512 Patent

  • The Term: "switching section that switches an operation of the inspection electrode on/off"
  • Context and Importance: This functional language is central to independent claim 1. The complaint’s infringement theory relies on mapping this limitation to the "selector circuitry" within the accused IC (Compl. ¶117). The viability of the infringement claim depends on whether this mapping is persuasive.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: A party could argue that any circuit element that achieves the result of connecting or disconnecting the signal path to the inspection electrode satisfies this limitation. The specification notes that the switching can be performed "manually" or "automatically," suggesting flexibility in implementation (’512 Patent, col. 3:7-10).
    • Evidence for a Narrower Interpretation: The patent specification provides a purpose for this element: enabling the electrode to "output a signal only when the signal needs to be monitored," which can "reduce power consumption" (’512 Patent, col. 3:1-4). Practitioners may focus on this stated purpose, arguing that the "switching section" must be a structure intended for this on/off inspection control, not a general-purpose signal multiplexer that is being re-characterized to meet the claim language.

VI. Other Allegations

Indirect Infringement

The complaint alleges both induced and contributory infringement against BOE, and induced infringement against Hisense (Compl. ¶57-68).

  • BOE: Inducement is alleged based on BOE selling its LCD panels to customers like Hisense with the knowledge and intent that they will be incorporated into infringing products for the U.S. market. Contributory infringement is alleged on the basis that the BOE panels are a material part of the patented inventions, are especially made for use in an infringing manner, and have no substantial non-infringing uses (Compl. ¶57-62).
  • Hisense: Inducement is alleged based on Hisense selling the accused TVs to end-users and encouraging their use, which constitutes direct infringement of the claimed devices and systems (Compl. ¶64-66).

Willful Infringement

  • The complaint alleges willful infringement against both defendants (Compl. ¶99). The claim against BOE is supported by detailed allegations of pre-suit knowledge dating back to January 2, 2020 for the ’146 patent and April 8, 2021 for the ’512 patent, stemming from licensing negotiations where Plaintiffs allegedly provided notice and claim charts (Compl. ¶55, 95). Willfulness for the ’020 patent is alleged as of the filing of the complaint (Compl. ¶53). The willfulness claim against Hisense is based on knowledge as of the filing of the complaint (Compl. ¶96).

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

  • A core issue will be one of technical characterization and scope: For the ’146 patent, can the signal supplied to the accused "clock signal input terminal" be proven to have the "higher frequency component" of a "driving signal" as required by the patent's disclosure to justify its larger size, or is it functionally equivalent to other signals?
  • A second key issue will be one of functional purpose versus capability: For the ’512 patent, does the accused IC's "selector circuitry" operate as a dedicated "switching section" for on/off inspection as the patent describes, or is it a general-purpose signal router whose incidental capability is being mapped to the claim language? The evidence regarding the primary design intent of this circuitry will be central.
  • A significant question for damages will be one of objective recklessness: Given the allegations of multi-year pre-suit notice and the exchange of claim charts, a court will have to determine whether BOE’s continued infringement of the ’146 and ’512 patents, if found, rises to the level of egregious conduct required for an award of enhanced damages.