DCT

2:25-cv-00412

Samsung Display CO., Ltd v. BOE Technology Group Co., Ltd.

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:25-cv-00412, E.D. Tex., 06/10/2025
  • Venue Allegations: Venue is alleged to be proper against the foreign-domiciled BOE entities in any judicial district. Venue against U.S. subsidiary BOE Technology America, Inc. is based on its alleged business activities directed toward the district, including maintaining a Houston office, and its role in placing the accused products into the stream of commerce in Texas.
  • Core Dispute: Plaintiff alleges that Defendant’s OLED displays, incorporated into smartphones and other devices, infringe four U.S. patents related to pixel circuit architecture, semiconductor layer structure, and integrated touch screen panel design.
  • Technical Context: The lawsuit concerns Organic Light Emitting Diode (OLED) displays, a dominant technology in the multi-billion dollar market for high-end consumer electronics such as smartphones.
  • Key Procedural History: The complaint alleges that Defendant BOE had pre-suit knowledge of at least some of the asserted patent families based on a May 2, 2022 notice letter. It also references a separate ITC investigation where a BOE entity allegedly admitted that screens it manufactures are imported into the United States, a fact which may be relevant to allegations of indirect infringement.

Case Timeline

Date Event
2010-09-14 ’088 Patent Priority Date
2012-08-02 ’990 and ’991 Patents Priority Date
2014-08-05 ’015 Patent Priority Date
2018-07-03 ’088 Patent Issue Date
2019-10-08 ’015 Patent Issue Date
2022-05-02 Samsung sends notice letter to BOE regarding related patents
2023-02-07 ’990 Patent Issue Date
2023-02-07 ’991 Patent Issue Date
2025-06-10 Complaint Filing Date

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

U.S. Patent No. 11,574,990 - "Organic Light Emitting Diode Display With Curved Channel Region"

The Invention Explained

  • Problem Addressed: The patent’s background describes a challenge in conventional OLED displays where the gate insulating layer for a driving thin-film transistor (TFT) must be thin to enable rapid switching. This thinness, however, narrows the transistor’s operational voltage range, making it difficult to precisely control the multiple levels of brightness (gray levels) required for high-quality images (US 11,574,990 B2, col. 1:51-62).
  • The Patented Solution: The invention proposes a novel pixel architecture where the semiconductor layer of the driving TFT is "bent" or arranged in a non-linear path, such as a zigzag or "S" shape. This longitudinally extends the channel region within the confined space of a pixel, which broadens the driving voltage range and allows for finer control over the OLED's brightness. The patent also describes a storage capacitor configured to overlap this bent semiconductor layer to maintain sufficient capacitance, which is critical for pixel stability in high-resolution displays (’990 Patent, Abstract; col. 9:30-67).
  • Technical Importance: This design purports to enhance display quality and resolution by overcoming a fundamental trade-off between transistor switching speed and voltage control range in pixel circuit design (’990 Patent, col. 4:50-62).

Key Claims at a Glance

  • The complaint asserts independent claim 1 (Compl. ¶43).
  • Claim 1 recites an organic light emitting diode display where each pixel's driving circuit comprises:
    • A first thin film transistor (TFT) coupled to a scan and data line.
    • A second TFT utilizing a semiconductor layer and coupled to a voltage line, the OLED, and the first TFT.
    • An insulating layer covering the second TFT.
    • A storage capacitor coupled to the gate electrode of the second TFT.
    • A key structural limitation: a portion of a channel region of the semiconductor layer under the gate electrode of the second thin film transistor being curved.
    • Third, fourth, fifth, and sixth TFTs with specified interconnections to other circuit elements.
  • The complaint does not explicitly reserve the right to assert dependent claims for this patent.

U.S. Patent No. 11,574,991 - "Organic Light Emitting Diode Display With Semiconductor Layer Having Bent Portion"

The Invention Explained

  • Problem Addressed: Similar to its sister ’990 patent, this patent addresses the technical problem of a narrow driving range for the driving TFT, which limits the ability to display a large number of gray levels accurately (’991 Patent, col. 1:51-62).
  • The Patented Solution: The invention claims a specific implementation of a semiconductor layer that has "at least one bent portion" and is used to form and interconnect multiple TFTs within a pixel's driving circuit. A distinguishing feature of the claimed solution is the spatial relationship between the bent semiconductor layer and the storage capacitor, requiring that "the bent portion of the second portion of the semiconductor layer is under the first capacitor plate." This integrated structure is designed to broaden the driving voltage range while maintaining a compact and efficient pixel layout (’991 Patent, Abstract; Claim 1).
  • Technical Importance: The invention offers a specific circuit layout intended to improve image fidelity in high-resolution displays by optimizing the physical structure of the pixel's core components (’991 Patent, col. 4:50-62).

Key Claims at a Glance

  • The complaint asserts independent claim 1 (Compl. ¶66).
  • Claim 1 recites an organic light emitting diode display with driving circuits, where each circuit comprises:
    • A first TFT implemented in a first portion of a semiconductor layer.
    • A second TFT implemented in a second portion of the semiconductor layer, which is coupled to the first TFT by the semiconductor layer itself.
    • A key structural limitation: the second portion of the semiconductor layer has at least one bent portion.
    • A storage capacitor with a first capacitor plate (operating as the second TFT's gate electrode) and a second capacitor plate.
    • Third and fourth TFTs implemented in third and fourth portions of the semiconductor layer with specified connections.
    • A key spatial limitation: the bent portion of the second portion of the semiconductor layer is under the first capacitor plate.
  • The complaint does not explicitly reserve the right to assert dependent claims for this patent.

U.S. Patent No. 10,439,015 - "Display Apparatus"

  • Patent Identification: U.S. Patent No. 10,439,015, “Display Apparatus,” issued October 8, 2019 (Compl. ¶30).
  • Technology Synopsis: The patent addresses potential signal integrity issues within a pixel's TFT structure. It discloses a "shield layer" positioned between a signal line and a semiconductor layer to prevent electrical interference (parasitic capacitance) that could otherwise degrade display quality (Compl. ¶30).
  • Asserted Claims: Independent claim 28 (Compl. ¶86).
  • Accused Features: The complaint alleges that BOE’s OLED displays contain a shield layer located between a signal line and the second semiconductor of a TFT, and that this shield layer overlaps a specific region between the channel areas of two different TFTs, as required by the claim (Compl. ¶¶92-93).

U.S. Patent No. 10,013,088 - "Flat Panel Display With Integrated Touch Screen Panel"

  • Patent Identification: U.S. Patent No. 10,013,088, “Flat Panel Display With Integrated Touch Screen Panel,” issued July 3, 2018 (Compl. ¶32).
  • Technology Synopsis: The patent describes a method for integrating a touch screen panel directly onto the display's protective sealing film. A key feature is that the end of this sealing film has an "inclined surface" to ensure that the conductive sensing lines running over this edge to the driving circuitry are not damaged during manufacturing, thereby improving yield and reliability (Compl. ¶32).
  • Asserted Claims: Independent claim 1 (Compl. ¶102).
  • Accused Features: The complaint alleges that BOE's displays incorporate an integrated touch panel where sensing cells and lines are formed on a sealing thin film, and that this film has a downwardly inclined surface over which the sensing lines extend to connect to a driving circuit (Compl. ¶¶107, 112, 114).

III. The Accused Instrumentality

Product Identification

  • The complaint identifies the accused instrumentalities as OLED displays manufactured, used, sold, or imported by the BOE defendants (Compl. ¶36). The OLED display panel within the "Nubia Z60 Ultra" smartphone, which was allegedly purchased in Texas, is used as a specific, exemplary accused product throughout the complaint (Compl. ¶42, ¶45).

Functionality and Market Context

  • The accused products are high-resolution OLED display modules used in consumer electronics. The complaint alleges that BOE is a supplier for device manufacturers like Nubia, citing Nubia's website which identifies BOE as the provider of its "Q9+ Screen material" (Compl. ¶39). The complaint provides extensive visual evidence from a teardown of a Nubia Z60 Ultra device, including photographs of the device chassis, the separated display panel substrate, and the glass panel. This annotated photograph shows the main components of the accused display assembly (Compl. ¶46, Fig. 4). The complaint also presents detailed micrograph images of the pixel-level circuitry on the display substrate to illustrate the allegedly infringing structures (e.g., Compl. ¶47, Fig. 5; ¶50, Fig. 9).

IV. Analysis of Infringement Allegations

’990 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a plurality of driving circuits on the substrate... The complaint provides annotated micrographs of the accused display panel, identifying repeating patterns of driving circuits, a first voltage line ("ELVDD"), and a second voltage line ("Vinit1"). ¶47 col. 6:20-24
wherein each of the driving circuits comprises: a second thin film transistor utilizing a semiconductor layer... The complaint identifies transistor T1 in the accused circuit as the second TFT, alleging it utilizes a semiconductor layer shown in annotated micrographs. ¶51 col. 7:1-6
a portion of a channel region of the semiconductor layer under the gate electrode of the second thin film transistor being curved; The complaint presents an annotated micrograph identifying a "Bent Portion" of the semiconductor layer allegedly associated with transistor T1. A cross-section view is also provided to show the layer structure. ¶53 col. 9:30-40
a third thin film transistor electrically coupled to the second thin film transistor... Transistor T6 in the accused product's circuit is identified as the third TFT, with its alleged electrical couplings to T1 and the OLED shown in circuit diagrams. ¶54 col. 7:26-31
a sixth thin film transistor electrically coupled to the second voltage line, the third thin film transistor, and the first capacitor plate... Transistor T4 is identified as the sixth TFT, and its alleged electrical connection to the second voltage line, T6, and the capacitor plate is described with reference to annotated micrographs. ¶57 col. 7:8-14
  • Identified Points of Contention:
    • Scope Questions: The infringement analysis may focus on whether the structure identified as "Bent Portion" in the complaint's micrographs (Compl. ¶53, Fig. 12) meets the claim limitation of being "curved." The parties may dispute whether this term implies a smooth arc or can encompass the angular, zigzag path shown in the patent's embodiments and allegedly found in the accused device.
    • Technical Questions: A central evidentiary question will be whether the complex six-transistor circuit laid out in the claim is actually implemented in the accused display. While the complaint labels transistors T1 through T6 on a micrograph (Compl. ¶54, Fig. 14), a defendant may argue that the physical layout or electrical functionality of one or more of these transistors differs from what the claim requires.

’991 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a plurality of driving circuits formed on the substrate; Annotated micrographs are provided to show repeating driving circuits, first voltage lines ("ELVDD"), scan lines ("Sn"), and data lines ("Dm") on the accused display's substrate. ¶71 col. 6:15-18
a second thin film transistor implemented in a second portion of the semiconductor layer... wherein the second portion of the semiconductor layer has at least one bent portion; The complaint identifies transistor T1 in the accused product as the second TFT and alleges it is formed in a second portion of a semiconductor layer containing a feature labeled as a "Bent Portion." ¶74 col. 8:3-8
a storage capacitor comprising: a first capacitor plate that is configured to operate as a gate electrode of the second thin film transistor; a second capacitor plate electrically coupled to one of the plurality of first voltage lines and overlapping the first capacitor plate; An annotated micrograph of the accused device allegedly shows a storage capacitor with a first plate (the gate of T1) and an overlapping second plate coupled to the ELVDD voltage line. A cross-section view purports to show the insulating layer between the plates. ¶75 col. 8:9-16
a fourth thin film transistor implemented in a fourth portion of the semiconductor layer... electrically coupled to the respective organic light emitting diode through the semiconductor layer; Transistor T6 in the accused device is identified as the fourth TFT, allegedly implemented in a fourth portion of the semiconductor layer and coupled to the OLED. ¶76 col. 8:27-33
wherein the bent portion of the second portion of the semiconductor layer is under the first capacitor plate. The complaint uses front and back side images of the driving circuits to allege that the "bent portion" is located spatially under the first capacitor plate. An annotated cross-section view is also provided to support this allegation. ¶77 col. 8:34-36
  • Identified Points of Contention:
    • Scope Questions: A primary issue for claim construction may be the meaning of "under" in the context of the limitation "the bent portion...is under the first capacitor plate." The parties could dispute whether this requires direct vertical alignment or allows for a more general spatial relationship as depicted in the complaint's cross-section diagram (Compl. ¶77, Fig. 28).
    • Technical Questions: The case may turn on whether the single, contiguous semiconductor layer claimed in the patent—which is described as being partitioned to form four distinct transistors—is present in the accused device. A defendant could argue its manufacturing process uses separate, non-contiguous semiconductor islands for each transistor, which would not meet the "implemented in a...portion of the semiconductor layer" and "semiconductor layer couples" limitations.

V. Key Claim Terms for Construction

  • The Term: "curved" / "bent portion" (asserted in '990 Patent, Claim 1; '991 Patent, Claim 1)
  • Context and Importance: This term is the central inventive concept described in the titles and abstracts of the two lead patents. The entire infringement theory for these patents rests on the allegation that the accused displays contain a semiconductor layer with this specific geometric characteristic. Practitioners may focus on this term because its construction will determine whether the non-linear path of the semiconductor layer observed in the accused product falls within the scope of the claims.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specifications state that the driving semiconductor layer may be in a "zigzag form," a "'ㄹ' form," or other shapes like "S," "M," and "W" (’990 Patent, col. 9:36-39, 9:65-67). This language suggests that "curved" or "bent" should not be limited to a smooth arc but can encompass a variety of non-linear, angular, or winding paths designed to lengthen the channel region.
    • Evidence for a Narrower Interpretation: The figures in the patents depict very specific, angular, zigzag-like layouts (e.g., ’990 Patent, Fig. 3, Fig. 6). A defendant may argue that the terms should be limited to these disclosed embodiments, or that they imply a specific functional outcome—broadening the gate voltage range—that must be demonstrated (’990 Patent, col. 9:40-50).

VI. Other Allegations

  • Indirect Infringement: The complaint alleges both induced and contributory infringement for all four patents. The inducement allegations are based on BOE allegedly supplying the infringing OLED displays to third-party device manufacturers with the knowledge and specific intent that they would be incorporated into products imported and sold in the U.S. (Compl. ¶¶60-61, 80-81). This allegation is supported by reference to a BOE entity's admission in an ITC proceeding that it sells screens that are subsequently imported into the U.S. (Compl. ¶61).
  • Willful Infringement: Willfulness is alleged based on pre-suit knowledge. For the '015 Patent, knowledge is alleged from at least a May 2, 2022 notice letter (Compl. ¶96). For the '990 and '991 Patents, knowledge is alleged from their issuance dates, based on the same May 2, 2022 letter which identified a parent patent from the same application family (Compl. ¶60, ¶80). For the '088 Patent, knowledge is alleged from its issuance date (Compl. ¶119). Continued infringing activity after receiving notice is alleged to be willful (Compl. ¶63, ¶83, ¶100, ¶122).

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

  • A core issue will be one of definitional scope: can the terms "curved" and "bent portion," which are central to the '990 and '991 patents, be construed to read on the specific, non-linear semiconductor paths identified in the accused BOE displays? The resolution will depend on whether the court adopts a broad, functional definition based on the goal of elongating the channel region, or a narrower one tied to the specific geometric layouts shown in the patent figures.
  • A key evidentiary question will be one of structural correspondence: do the intricate, multi-layer structures identified in the accused product through reverse engineering—such as the "shield layer" of the '015 patent and the "inclined surface" of the '088 patent's sealing film—possess the precise location, composition, and relationship to other components as required by the asserted claims? The dispute will likely involve competing expert analyses of the detailed micrograph and cross-section evidence presented in the complaint.
  • A third significant question will concern knowledge and intent: does the evidence of a pre-suit notice letter regarding related patents and admissions in a separate ITC investigation provide a sufficient factual basis to support the claims for indirect and willful infringement? The court will need to determine if these facts establish that BOE knew of the specific patents-in-suit and intended for its customers to infringe them in the U.S.