PTAB

IPR2013-00060

Chi Mei Innolux Corp v. Semiconductor Energy Laboratory Co Ltd

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1. Case Identification

2. Patent Overview

  • Title: Contact Structure
  • Brief Description: The ’102 patent discloses an active matrix liquid crystal display (LCD) device. The technology centers on the structure of a thin-film transistor (TFT) substrate, including the specific arrangement of internal conducting lines, extractor terminals for external power, and a common terminal formed from the same layer as the pixel electrode.

3. Grounds for Unpatentability

Ground 1: Obviousness over Shiba and Moriyama - Claims 15, 17, 18, 27, 29, 30, 39, 41, and 42 are obvious over Shiba in view of Moriyama.

  • Prior Art Relied Upon: Shiba (Patent 5,684,555) and Moriyama (Japanese Patent Publication No. JP 05-243333).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Shiba disclosed the majority of the claimed elements, including the fundamental structure of an active matrix display with a pixel region, TFTs, extractor terminals, a counter electrode, and internal conducting lines. Shiba also taught forming a "first internal conducting line" in the same processing step as the gate electrode and a "second internal conducting line" in the same step as the source/drain electrodes. The Petitioner asserted that Moriyama supplied the missing limitation of independent claims 15, 27, and 39, which require the "common terminal" of the extractor terminal to be "formed from a same layer as the pixel electrode." Moriyama explicitly taught that this practice was well-known. Dependent claims were argued to be obvious as Shiba disclosed using bottom-gate TFTs (claims 17, 29, 41) and transparent Indium Tin Oxide (ITO) for the pixel electrode (claims 18, 30, 42).
    • Motivation to Combine: Petitioner contended a person of ordinary skill in the art (POSITA) would combine Moriyama's teaching with Shiba's display structure to improve reliability. Moriyama explained that using the transparent metal layer of the pixel electrode for the common terminal was desirable because it resists oxidation, leading to a more reliable connection. A POSITA would have recognized this known benefit and applied it to the otherwise conventional display device disclosed in Shiba.
    • Expectation of Success: The combination involved applying a known material to a known component for its predictable, advantageous property (oxidation resistance). Petitioner asserted this was a simple substitution with a high expectation of success.

Ground 2: Obviousness over Admitted Prior Art and Shiba - Claims 15, 17, 18, 27, 29, 30, 39, 41, and 42 are obvious over the Admitted Prior Art of the ’102 patent in view of Shiba.

  • Prior Art Relied Upon: The Admitted Prior Art (APA) from the prosecution history of the ’102 patent and Shiba (Patent 5,684,555).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the APA of the ’102 patent itself disclosed a basic active matrix display structure, including a common terminal formed from the same layer as the pixel electrode. However, the APA lacked specific teachings on the arrangement of internal conducting lines around the periphery of the substrate and the co-fabrication of conducting lines with TFT electrodes in distinct processing steps. Petitioner contended that Shiba supplied these missing elements. Shiba disclosed the specific claimed arrangement of internal conducting lines extending along three sides of the LCD substrate and taught that a conducting line could be formed in the same processing step as the gate electrode.
    • Motivation to Combine: A POSITA, starting with the basic structure disclosed in the APA, would have been motivated to consult references like Shiba to implement a practical and efficient wiring layout. Shiba provided a known, effective solution for arranging the conducting lines and for integrating their fabrication with the standard TFT manufacturing process. Petitioner argued this combination represented a predictable choice of known design options to arrive at the claimed invention.
    • Expectation of Success: Integrating Shiba's well-understood wiring layout and manufacturing steps into the general display structure of the APA would have been a straightforward task for a POSITA. No new or unpredictable results would arise from this combination, leading to a high expectation of success.

4. Relief Requested

  • Petitioner requests institution of an IPR and cancellation of claims 15, 17, 18, 27, 29, 30, 39, 41, and 42 of the ’102 patent as unpatentable.