PTAB

IPR2025-01477

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

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1. Case Identification

2. Patent Overview

  • Title: Display Device
  • Brief Description: The ’496 patent describes an Organic Light Emitting Diode (OLED) display device with an integrated touch sensing unit. The technology focuses on the specific layered arrangement, including a display panel with red, green, and blue light-emitting areas of different sizes, a multi-layer thin-film encapsulation layer, and a touch sensing unit with two conductive patterns of different thicknesses formed on the display panel.

3. Grounds for Unpatentability

Ground 1A: Obviousness over Her, Cok, and Cho - Claims 1-10 and 12 are obvious over Her in view of Cok and Cho.

  • Prior Art Relied Upon: Her (Application # 2015/0049030), Cok (Patent 6,867,549), and Cho (Application # 2014/0117330). Petitioner also noted that Hsieh (Chinese Application # CN105320372A) and/or Kobayashi (Japanese Patent # JPH0646348B2) could optionally be added.
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Her discloses the foundational structure: an OLED display with a base substrate, circuit layer, OLED layer with red, green, and blue light-emitting areas, and a sealing/encapsulation layer. Her further teaches a touch panel formed on this encapsulation layer, comprising two conductive patterns (one of which can be a bridge) separated by an insulating layer, with the touch sensors forming a mesh aligned with the light-emitting areas. However, Her does not specify different sizes for the light-emitting areas or a multi-layer structure for its "sealing layer." Cok was cited for its teaching that varying the sizes of red, green, and blue pixels improves display performance by accounting for differences in color efficiency, degradation, and human eye sensitivity. Cho was cited for disclosing a conventional multi-layer thin-film encapsulation structure with alternating organic and inorganic layers to protect the OLED from moisture and oxygen.
    • Motivation to Combine: A POSITA would combine Cok's teaching of different-sized pixels with Her's display to optimize performance, a well-known and predictable design modification. A POSITA would have also been motivated to implement Cho's robust, multi-layer encapsulation in place of Her's generically disclosed "sealing layer" to improve the display's durability and reliability, consistent with conventional OLED manufacturing practices.
    • Expectation of Success: Petitioner asserted a POSITA would have had a reasonable expectation of success because the combinations involved applying known solutions (variable pixel sizes, multi-layer encapsulation) to a conventional display structure (Her) to achieve their expected benefits.

Ground 2A: Obviousness over Lee-979, Kim, and Cok - Claims 1-10 and 12 are obvious over Lee-979 in view of Kim and Cok.

  • Prior Art Relied Upon: Lee-979 (Application # 2014/0145979), Kim (Application # 2013/0341651), and Cok (Patent 6,867,549). Petitioner also noted optional additions of Hsieh and/or Kobayashi.

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner asserted that Lee-979 discloses a flexible OLED display with a substrate, circuit layer, OLED layer, and a multi-layer encapsulation structure. Crucially, Lee-979's touch-sensing unit is disposed within the encapsulation layer and is made from a transparent conductive material like Indium Tin Oxide (ITO). To address the limitation that the touch sensors comprise metal mesh lines, Petitioner cited Kim. Kim teaches using metal mesh for touch sensors instead of ITO, as metal mesh offers superior flexibility and lower resistance, which is advantageous for flexible displays. Kim explicitly teaches arranging the metal mesh lines in the gaps between pixels to avoid obstructing light. Cok was again cited for the rationale of using different-sized light-emitting areas.
    • Motivation to Combine: A POSITA would combine Kim with Lee-979 by substituting Lee-979's ITO-based touch sensor with Kim's metal mesh sensor. The motivation was strong because ITO was known to have drawbacks in flexible displays (brittleness, higher resistance), and metal mesh was a known, superior alternative. This substitution would predictably improve the durability and electrical performance of Lee-979's flexible display. A POSITA would then align the mesh holes with Lee-979’s pixels, as taught by Kim, to maintain display brightness. The motivation to incorporate Cok's teachings on pixel size is the same as in Ground 1A.
    • Expectation of Success: The expectation of success was high, as it involved the simple substitution of one known touch sensor material (ITO) with another known, superior material (metal mesh) to achieve predictable improvements in a flexible display.

  • Additional Grounds: Petitioner asserted additional obviousness challenges based on the same core combinations. Ground 1B added Lee-P12 (a 2004 SID Digest article) to the Her combination to teach the specific seven-transistor pixel driving circuit of claims 11 and 17. Ground 1C added Ka (Application # 2014/0002385) to the Her combination to render claims 13-16 obvious by teaching features for foldable displays. Grounds 2B and 2C mirrored this strategy for the Lee-979 combination, adding Lee-P12 and Ka, respectively.

4. Relief Requested

  • Petitioner requests the institution of an inter partes review and the cancellation of claims 1-17 of the ’496 patent as unpatentable.