PTAB

IPR2014-01362

LG Display Co Ltd v. Innovative Display Technologies LLC

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Petition

1. Case Identification

2. Patent Overview

  • Title: Light Emitting Panel Assembly
  • Brief Description: The ’177 patent discloses light emitting panel assemblies used as backlights for displays like LCDs. The assemblies include a tray with a cavity, at least one light source within the cavity, and at least one overlying sheet, film, or substrate for controlling the emitted light.

3. Grounds for Unpatentability

Ground 1: Obviousness over Melby - Claims 1-3, 5-7, 9-10, 13-15, 19, 21, and 23-25, 27 are obvious over Melby.

  • Prior Art Relied Upon: Melby (Patent 5,054,885).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Melby, which discloses a light fixture for flat panel displays, teaches all limitations of the challenged claims across its different embodiments. Melby’s housing (30) with continuous side walls and a back wall forms the claimed “tray having a back wall and continuous side walls that form a hollow cavity.” This housing includes mounted light sources (42, 44), satisfying the light source limitation. Finally, Melby’s transparent or translucent cover (40) is the claimed “sheet, film or substrate overlying the assembly.”
    • Motivation to Combine: Petitioner asserted that a person of ordinary skill in the art (POSITA) would be motivated to pick and choose features from the different embodiments described within the single Melby reference, as they are taught together without any suggestion that they cannot be combined.
    • Expectation of Success: A POSITA would have had a high expectation of success in combining features from within the same patent to arrive at the claimed invention, as it would be a matter of routine design optimization.

Ground 2: Anticipation by Nakamura - Claims 1, 2, 6, 7, 9, 10, 13, 14, 15, 19, 21, 23-24, and 26 are anticipated by Nakamura.

  • Prior Art Relied Upon: Nakamura (Patent 5,453,855).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that Nakamura, which discloses a back-illuminated liquid crystal display device, inherently discloses every element of the challenged claims. Nakamura’s “shallow box-form holder” (24) with side walls (24a, 24b) and a reflection-treated inner surface is the claimed tray. The holder contains a plurality of LEDs (2), meeting the light source limitation. A light-diffusing plate (25), which is a sheet or film, is installed in the opening of the holder, thereby overlying the assembly. Secondary reflective surfaces are disclosed as trapezoidal projections (27) and hill-shaped raised portions (28) on the inner surface of the holder, which redirect light.

Ground 3: Obviousness over Sasuga and Farchmin - Claims 1, 2, 6, 7, 9, 10, 13, 15, and 21 are obvious over Sasuga in view of Farchmin.

  • Prior Art Relied Upon: Sasuga (Patent 5,432,626), Farchmin (Patent 5,567,042).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued that Sasuga discloses a display module with nearly all claimed features, including a lower casing (LCA) acting as a tray, back lights (BL) as the light source, and an optical diffusion board (SPB) as the overlying sheet. However, Sasuga’s casing has notches for routing connectors, meaning its side walls are not continuous. Farchmin was cited for its disclosure of a backlight unit with a molded plastic reflector (26) that forms a tray with a back wall and continuous, reflective side walls.
    • Motivation to Combine: A POSITA would combine Farchmin's continuous side wall structure with Sasuga’s assembly because both references are directed to back-lit devices and address similar problems of light reflection and distribution. A POSITA would see Farchmin’s fully enclosed tray as a simple design alternative for Sasuga’s notched tray to improve light containment and structural integrity.
    • Expectation of Success: Combining these known elements from the same field would have been straightforward, predictable, and successful, as it involves substituting one type of housing for another to achieve a well-understood benefit.

  • Additional Grounds: Petitioner asserted additional challenges, including that claims 1, 2, 13, and 14 are obvious over Baur (Patent 4,142,781) alone, and that various other claims are obvious over Baur in view of Nakamura. Further combinations involving Sasuga, Farchmin, and either Nakamura or Pristash (Patent 5,005,108) were also asserted to render additional claims obvious by teaching specific types of deformities or light sources.

4. Key Claim Construction Positions

  • "deformities" (claims 14, 23-27): Petitioner argued this term should be construed to mean "any change in the shape or geometry of a surface and/or coating or surface treatment that causes a portion of the light to be emitted." This construction was based on an explicit definition provided in the specification of the ’177 patent.

5. Key Technical Contentions (Beyond Claim Construction)

  • Physical Impossibility of Independent Claims: Petitioner contended that independent claims 1 and 15, as amended during prosecution, recite a physical impossibility. The claims require a "sheet, film or substrate overlying the assembly," but the assembly is defined as comprising that same sheet, film, or substrate. Petitioner argued a component cannot simultaneously be part of an assembly and overlie the entire assembly of which it is a part.

6. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1-3, 5-7, 9-10, 13-15, 19, 21, and 23-27 of the ’177 patent as unpatentable.