Mianyang BOE Optoelectronics Technology Co Ltd v. Samsung Display Co Ltd

1. Case Identification

• Case #: IPR2023-00988
• Patent #: 10,854,683
• Filed: June 21, 2023
• Petitioner(s): Mianyang BOE Optoelectronics Technology Co., Ltd.; Wuhan China Star Optoelectronics Semiconductor Display Technology Co., Ltd.; Tianma Microelectronics Co. Ltd.; and Visionox Technology, Inc.
• Patent Owner(s): Samsung Display Co., Ltd.
• Challenged Claims: 1-2, 4-10, 13, and 15

2. Patent Overview

• Title: Pixel Arrangement Structure for Organic Light Emitting Display Device
• Brief Description: The ’683 patent relates to a pixel arrangement for an organic light-emitting diode (OLED) display designed to improve display lifespan. The claimed structure arranges green pixels at the intersection of crossing lines, surrounded by larger red and blue pixels.

3. Grounds for Unpatentability

Ground 1: Obviousness over Matthies and Yamada - Claims 1-2, 4-10, 13, and 15 are obvious over Matthies in view of Yamada.

• Prior Art Relied Upon: Matthies (Patent 6,897,855) and Yamada (Patent 6,366,025).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Matthies teaches an OLED display with red, green, and blue sub-pixels in a "quad sub-pixel structure" arranged in an evenly spaced, repeating square matrix. This configuration inherently meets the challenged claims’ limitations for pixels arranged along crossing "first" and "second" lines, with blue pixels ("second pixels") and red pixels ("third pixels") positioned on opposite sides of the green pixels ("first pixels"). While Matthies discloses pixels of equal size, Yamada teaches that to improve OLED lifespan and avoid premature deterioration, pixels should be sized according to their emission efficiency. Specifically, Yamada teaches making the blue pixel (lowest efficiency) the largest and the green pixel (highest efficiency) the smallest. Petitioner contended that applying Yamada's well-known sizing principle to the pixel layout in Matthies would result in the claimed pixel arrangement and size hierarchy.
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine these references to solve the known problem of OLED pixel aging and decay, which Matthies acknowledges but addresses with complex circuitry. Yamada provides a direct and simpler solution by resizing pixels based on emission efficiency, which was a known method to extend display life. This combination would not only improve the longevity of Matthies' display but also simplify its design by reducing the need for complex current-management components, aligning with the industry goal of reducing manufacturing costs.
  • Expectation of Success: A POSITA would have a high expectation of success, as resizing pixels to improve display lifetime was a routine design option in the art. Both references are directed to pixel designs for OLED displays, making the application of Yamada’s teachings to Matthies’ layout a predictable and straightforward modification.

Ground 2: Obviousness over Murai and Yamada - Claims 1-2, 4-10, 13, and 15 are obvious over Murai in view of Yamada.

• Prior Art Relied Upon: Murai (JP 4496852) and Yamada (Patent 6,366,025).

• Core Argument for this Ground:

  • Prior Art Mapping: Petitioner asserted that Murai discloses an OLED display with red, green, and blue dots arranged in a square grid, satisfying the claimed layout of pixels along crossing lines. Murai explicitly teaches adjusting pixel area by using corner "cut-off portions," and an embodiment in Figure 3 already shows green dots made smaller than the red and blue dots. To achieve the specific claimed hierarchy where blue pixels are also larger than red pixels, a POSITA would look to Yamada. Petitioner argued that applying Yamada’s teaching—making blue pixels largest, red intermediate, and green smallest—using Murai’s own disclosed cut-off mechanism would be an obvious modification that meets all limitations of the challenged claims.
  • Motivation to Combine: A POSITA would be motivated to apply Yamada's teachings to Murai for the same reasons as with Matthies: to improve display life and simplify design. Murai already provides the mechanism for creating different pixel sizes (the cut-offs) to improve image quality. A POSITA would recognize that this existing design feature could be leveraged to implement Yamada's solution for improving display longevity, which would reduce pixel deterioration and allow for a more simplified current supply to the pixels.
  • Expectation of Success: The expectation of success would be high because Murai already teaches differently sized pixels. Applying Yamada's established method for improving display life by adjusting pixel sizes would be a predictable application of a known technique to solve a known problem, constituting a routine design variation rather than an inventive step.

• Additional Grounds: Petitioner asserted additional obviousness challenges, including that claims 1, 4-10, 13, and 15 are obvious over Phan (Patent 7,091,986) alone, and that claim 2 is obvious over Phan in view of Yamada, relying on similar pixel arrangement and sizing modification arguments.

4. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under 35 U.S.C. §325(d) would be inappropriate. The petition relies on primary references (Matthies, Phan, and Murai) that were not considered during prosecution. Although Yamada was listed as a reference on the face of the ’683 patent, the Examiner did not substantively discuss or apply its teachings, rendering the arguments in the petition new and materially different from those previously considered by the USPTO.

5. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-2, 4-10, 13, and 15 of Patent 10,854,683 as unpatentable.