PTAB

IPR2013-00038

Chimei Innolux Corp v. Semiconductor Energy Laboratory Co Ltd

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1. Case Identification

2. Patent Overview

  • Title: Liquid-Crystal Display Device Having a Particular Conductive Layer
  • Brief Description: The ’978 patent discloses a liquid-crystal display (LCD) device that addresses non-uniform seals caused by peripheral drive circuits and signal lines. The invention uses electrically isolated "dummy" wiring structures that overlap with the sealing region to equalize the gap between substrates, thereby creating a more consistent seal and improving image quality.

3. Grounds for Unpatentability

Ground 1: Obviousness over Sono - Claims 7 and 17 are obvious over Sono.

  • Prior Art Relied Upon: Sono (Patent 5,513,028).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Sono addressed the same problem as the ’978 patent: non-uniform gaps in LCD devices caused by topological "steps" from peripheral circuits. Sono was asserted to teach the use of electrically insulated "dummy areas" with dummy pixels, circuits, or wiring around the display's periphery to create a uniform cell gap. Petitioner contended these dummy structures in Sono met the limitations of the challenged claims, including being formed from the same layers as active conductive lines, overlapping with a sealing member, and having a width corresponding to multiple scanning lines. For claim 17, Sono was also cited for teaching the use of an opaque black matrix to improve image sharpness.
    • Motivation to Combine (for §103 grounds): This ground relied on a single reference, arguing Sono itself rendered the claims obvious. The motivation was inherent in Sono's express purpose: to solve the known problem of unevenness in display color and non-uniform gaps by using dummy structures, which directly aligned with the purported invention of the ’978 patent.
    • Expectation of Success (for §103 grounds): Petitioner asserted a POSITA would have had a high expectation of success because Sono explicitly taught that its dummy wiring approach resulted in a high-quality image display by creating a uniform gap.

Ground 2: Obviousness over APA and Sono - Claims 7 and 17 are obvious over Applicant's Admitted Prior Art in view of Sono.

  • Prior Art Relied Upon: Applicant's Admitted Prior Art ("APA") from the ’978 patent specification and Sono (Patent 5,513,028).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that the APA in the ’978 patent specification disclosed the basic elements of a conventional active matrix LCD, including substrates, conductive scanning and signal lines, transistors, and a sealing member. The allegedly distinguishing features of the ’978 patent—the use of electrically isolated dummy conductive layers to create a uniform step for the sealing material—were argued to be explicitly taught by Sono. Petitioner mapped the APA to the conventional LCD elements of the claims and mapped Sono's teachings on dummy wiring to the remaining claim limitations.
    • Motivation to Combine (for §103 grounds): A POSITA, starting with the conventional LCD described in the APA, would have recognized the known problem of non-uniform seals discussed in both the ’978 patent and Sono. A POSITA would combine Sono's well-understood solution of using dummy structures with the conventional APA device to improve its reliability and image quality by creating a more uniform seal.
    • Expectation of Success (for §103 grounds): Success was expected because Sono provided a clear, established method for correcting the precise structural non-uniformity problem inherent in the device described by the APA.

Ground 3: Obviousness over APA, Watanabe, and Sono - Claims 7 and 17 are obvious over Applicant's Admitted Prior Art in view of Watanabe and Sono.

  • Prior Art Relied Upon: APA from the ’978 patent specification, Watanabe (Patent 5,504,601), and Sono (Patent 5,513,028).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground presented a similar argument to Ground 2, but introduced Watanabe as an alternative or additional source for the key teachings. Petitioner argued that Watanabe, like Sono, disclosed using "substrate gap adjusting layers" (dummy areas) along the periphery to ensure a uniform step for the sealing material and high image quality. Watanabe was asserted to teach forming these dummy layers from the same material as the active scanning or signal lines and patterning them to be electrically isolated. Sono was additionally cited for its teaching of using a black matrix to improve contrast (relevant to claim 17) and for its disclosure that dummy structures could have a width corresponding to multiple scanning lines.
    • Motivation to Combine (for §103 grounds): A POSITA would combine the conventional LCD of the APA with Watanabe's teachings to solve the known problem of non-uniform sealing. A POSITA would further incorporate the teachings of Sono to optimize the width of the dummy structures and add a black matrix for enhanced image sharpness, both of which were known techniques for improving display quality.
    • Expectation of Success (for §103 grounds): A POSITA would have reasonably expected success, as both Watanabe and Sono provided detailed instructions for creating dummy structures to achieve a uniform device gap, a known method for producing more reliable LCDs with better image quality.

4. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 7 and 17 of Patent 7,956,978 as unpatentable.