PTAB

IPR2022-00508

Samsung Display Co Ltd v. Bishop Display Tech LLC

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Key Events
Petition

1. Case Identification

2. Patent Overview

  • Title: Liquid Crystal Display Panel
  • Brief Description: The ’829 patent discloses liquid crystal displays (LCDs) using in-plane switching (IPS) technology. The purported improvements aim to increase the aperture ratio and reduce image quality degradation by using specific pixel structures, such as having an electrode adjacent to a signal line be made of an opaque conductor while other electrodes are transparent, or by incorporating light shielding members.

3. Grounds for Unpatentability

Ground 1: Anticipation by Ohta - Claims 1, 5, 10, 11, 18, 19, and 28–37 are anticipated by Ohta under 35 U.S.C. §102.

  • Prior Art Relied Upon: Ohta (International Publication No. WO 98/27454).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Ohta, which was not considered during prosecution, discloses every element of the challenged claims. Specifically, independent claim 1 requires that of the pixel and common electrodes, the one adjacent to a signal line comprises an opaque conductor, while at least one other comprises a transparent conductor. Petitioner asserted that Ohta’s Figure 23 explicitly teaches this structure, showing "non-transparent counter electrodes adjacent to the image signal lines" and pixel electrodes made from a "transparent conductive film." Similarly, Petitioner contended that Ohta discloses the "light shielding member" required by independent claim 29, teaching a "light blocking film BM (so-called black matrix)" that covers the region between the adjacent electrode and the image signal line. The petition provided a detailed, element-by-element mapping for all challenged claims based on two primary embodiments disclosed in Ohta.

Ground 2: Anticipation by Kawano - Claims 1–5, 10, 11, 18, 19, 28–30, and 37 are anticipated by Kawano under 35 U.S.C. §102.

  • Prior Art Relied Upon: Kawano (Patent 6,337,726).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground was presented based on the Patent Owner's apparent interpretation of "common electrode" from parallel district court litigation. Petitioner argued that if the term is construed broadly to include structures that do not necessarily generate an electric field with the pixel electrode, then Kawano anticipates the claims. Kawano, also not cited during prosecution, discloses "light shielding layers 90" adjacent to image signal lines that are formed from an opaque molybdenum-tungsten (Mo-W) film. Under the Patent Owner's alleged broad construction, these opaque layers function as the claimed "common electrode." Kawano further discloses that its "display pixel electrodes" may be formed of transparent materials like ITO. Petitioner asserted this combination of an opaque "common electrode" adjacent to the signal line and a transparent pixel electrode meets the key limitation of claim 1. Kawano was also alleged to disclose a "light shielding layer (or black matrix) 82" that meets the limitations of claims requiring such a member.

  • Additional Grounds: Petitioner asserted that all challenged claims are also obvious under 35 U.S.C. §103 based on Ohta (Ground II) and Kawano (Ground IV), respectively. These grounds relied on the same teachings as the anticipation grounds, arguing that to the extent any limitation is not explicitly disclosed, it would have been obvious to a person of ordinary skill in the art (POSITA).

4. Key Claim Construction Positions

  • "common electrode": This term was identified as central to the dispute. Petitioner contended that for the purposes of the IPR, the term should be construed functionally to require an electrode that "generates an electric field for modulating the liquid crystal molecules, in conjunction with a pixel electrode." However, Petitioner noted that in parallel litigation, the Patent Owner appeared to be asserting a broader, purely structural definition where elements are "common electrodes" irrespective of function, based on their location. Petitioner argued that the prior art anticipates the claims under either construction, with Ohta satisfying the functional definition and Kawano satisfying the Patent Owner's broader structural definition.

5. Arguments Regarding Discretionary Denial

  • Petitioner argued that discretionary denial under §314(a) based on the Fintiv factors would be inappropriate. The core arguments were that the parallel district court proceeding is in a very early stage, with no significant investment from the court or parties and an uncertain trial schedule involving 13 patents. Petitioner also asserted a lack of overlap in issues, as the IPR challenges claims not asserted in the litigation and Petitioner offered a stipulation not to pursue the same invalidity grounds in district court if the IPR is instituted. Finally, Petitioner claimed the petition has strong merits, relying on prior art references that were never considered by the patent examiner.

6. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1–5, 10, 11, 18, 19, and 28–37 of the ’829 patent as unpatentable.