PTAB

IPR2022-00505

Samsung Display Co Ltd v. Bishop Display Tech LLC

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Liquid Crystal Display and Fabrication Method Thereof
  • Brief Description: The ’682 patent relates to a liquid crystal display (LCD) of the transversal electric field or in-plane switching (IPS) type. The patent claims a structure where at least one key component—such as the scanning lines, video signal lines, pixel electrode, or common electrode—is at least partially made of a two-layer structure comprising a light-transmitting conductive layer and a light-non-transmitting conductive layer to improve display luminance and contrast.

3. Grounds for Unpatentability

Ground I: Claims 7 and 9 are obvious over Matsumoto

  • Prior Art Relied Upon: Matsumoto (Japanese Patent Application Publication No. H09-269508).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Matsumoto, which was not considered during prosecution, discloses an IPS-mode LCD addressing the same problems of low luminance and contrast as the ’682 patent. Matsumoto’s pixel electrode (15) and counter electrode (16) are explicitly described as having a "two-layered structure" with a light-blocking layer (41, e.g., chromium) overlapping a transparent layer (40, e.g., Indium Tin Oxide, or ITO). Petitioner asserted this structure meets the core limitation of independent claim 7 requiring an electrode partially constituted by light-transmitting and light-non-transmitting conductive layers. Matsumoto further discloses that the transparent layer (10 µm) is wider than the light-blocking layer (5 µm), satisfying another limitation of claim 7. For dependent claim 9, Petitioner contended that Matsumoto’s disclosure of chromium for the light-non-transmitting layer and ITO for the light-transmitting layer satisfies the claim, as chromium is known to have higher electrical conductivity (lower resistivity) than ITO.
    • Motivation to Combine: Although a single-reference ground, Petitioner argued that to the extent Matsumoto does not explicitly detail the standard operation of an active matrix display (i.e., sequentially selecting pixels), it would have been obvious to a person of ordinary skill in the art (POSITA). A POSITA would apply this known technique to a known device (Matsumoto's LCD) to achieve the predictable result of displaying an image.
    • Expectation of Success: A POSITA would have had a high expectation of success in operating the Matsumoto display using conventional sequential scanning, as this was the prevalent and standard method for driving active matrix LCDs.

Ground II: Claims 7–10 are anticipated by Ohta

  • Prior Art Relied Upon: Ohta (International Publication No. WO 98/27454).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Ohta, also not considered during prosecution, discloses every element of the challenged claims. Ohta describes an IPS-type display with a common electrode (counter electrode CT) “constituted from of double wiring,” where a transparent ITO film (11) is formed covering a non-transparent aluminum (Al) layer (10). This directly teaches the two-layer conductive structure of claim 7. Ohta discloses that the ITO film completely covers the underlying Al layer, thus teaching the "wider" transparent layer limitation of claim 7. For dependent claim 8, Ohta teaches layering the non-transparent Al layer on the inner substrate surface and then layering the transparent ITO film over the Al layer. For claim 9, Ohta’s use of aluminum (non-transparent) and ITO (transparent) meets the limitation, as aluminum has a higher electrical conductivity than ITO. For independent claim 10, Ohta’s common electrode is formed directly on the glass substrate, making it the component "disposed closest to the inner surface" of the substrate, as required.

Ground III: Claims 7–10 are obvious over Ohta

  • Prior Art Relied Upon: Ohta (International Publication No. WO 98/27454).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground was presented as an alternative to Ground II, arguing that if Ohta does not anticipate the claims, it renders them obvious. Petitioner contended that Ohta teaches or suggests all structural elements of the claims for the same reasons articulated in Ground II. The obviousness argument focused primarily on the functional limitation of displaying an image by sequentially selecting pixels.
    • Motivation to Combine: If Ohta were found not to explicitly teach the sequential scanning method, a POSITA would combine Ohta's disclosed display structure with the well-known technique of sequential scanning. The motivation was that this was the standard, ubiquitous, and necessary method for operating a TFT active matrix LCD to display an image, making its application to Ohta's device a matter of routine design.
    • Expectation of Success: A POSITA would have expected this combination to work for its intended purpose, as it represented the application of a conventional technique to a compatible device to yield a predictable outcome.

4. Arguments Regarding Discretionary Denial

  • Petitioner argued that discretionary denial under 35 U.S.C. §314(a) based on Fintiv factors was not warranted. The district court litigation was in an early stage, with the trial date being uncertain due to the complexity of litigating 13 patents simultaneously. Petitioner noted a lack of substantive overlap between the proceedings, as this inter partes review (IPR) challenges claims (8 and 10) not asserted in the district court. Furthermore, Petitioner offered a stipulation not to pursue in district court the same grounds or prior art references asserted in the IPR. Finally, Petitioner argued the petition presented strong merits based on prior art that the Patent Office had not previously considered.

5. Relief Requested

  • Petitioner requests institution of IPR and cancellation of claims 7-10 of the ’682 patent as unpatentable.