PTAB

IPR2015-01866

KJ Pretech Co Ltd v. Innovative Display Technologies

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1. Case Identification

2. Patent Overview

  • Title: Light Emitting Panel Assembly
  • Brief Description: The ’816 patent describes light emitting panel assemblies, such as those used for liquid crystal display (LCD) backlights. The technology centers on a transparent panel member designed to efficiently conduct light from a side-mounted source and control its emission from a primary surface using features like light-extracting deformities and reflectors.

3. Grounds for Unpatentability

Ground 1: Claims 1, 3, and 4 are anticipated by Tsunoda under 35 U.S.C. § 102

  • Prior Art Relied Upon: Tsunoda (JP 6-51130).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Tsunoda, which discloses a surface lighting device, teaches every limitation of the challenged claims. Petitioner mapped Tsunoda’s light source (LEDs) and light-guide plate with a light input edge to the corresponding elements of claim 1. The claimed "tray or housing having a cavity" was alleged to be disclosed by Tsunoda's "holder (9)" which receives the light-guide plate. The "pattern of light extracting deformities" was mapped to Tsunoda's disclosure of forming columnar projections, depressed holes, or surface coarsening to make light emit uniformly. Finally, Petitioner asserted that Tsunoda’s reflective holder, made of a white material, and its optional reflective films meet the limitations for end and side edge reflectors required by claims 1 and 3.

Ground 2: Claims 1, 3, and 4 are obvious over Pristash under 35 U.S.C. § 103

  • Prior Art Relied Upon: Pristash (Patent 5,005,108).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that Pristash, which discloses thin panel illuminators for LCD backlighting, renders the claims obvious. Pristash was argued to teach a light emitting assembly with a light source (including LEDs), a transparent panel with an input edge, and surface "disruptions" that function as the claimed "deformities" to extract light. Critically, Petitioner mapped the claimed "refractive surface" at the input edge to Pristash’s disclosure of a lens-shaped or tapered "transition device 5" that is integral with the panel and functions to spread light across the panel's width.
    • Motivation to Combine (within the single reference): For the "tray or housing" limitation, Petitioner argued that a person of ordinary skill in the art (POSITA) would find it obvious to enclose the light guide of Pristash's Figure 1 within the complete set of back, end, and side reflectors disclosed in Pristash's Figure 8. A POSITA would combine these teachings from within Pristash to achieve the well-known benefits of preventing light loss and providing necessary structural support for an LCD backlight assembly.
    • Expectation of Success: A POSITA would have had a high expectation of success, as this combination merely involved using components taught by Pristash for their stated and understood functions.

Ground 3: Claims 1, 3, and 4 are obvious over Pristash in view of Suzawa under §103

  • Prior Art Relied Upon: Pristash (Patent 5,005,108) and Suzawa (Patent RE 33,987).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner presented this ground as an alternative in the event the Board found Pristash alone insufficient to render the "tray or housing" limitation obvious. While Pristash provides the core light panel assembly, Suzawa was introduced for its explicit teaching of a housing structure. Suzawa discloses a "light scattering and reflecting element" that acts as a tray to completely enclose a photoconductor used in an LCD backlight, thereby meeting the housing limitation of claim 1 and the reflector placement limitations of claim 3.
    • Motivation to Combine: A POSITA would combine the references because both relate directly to backlight technology for LCDs. Pristash expressly suggests its illuminators for this purpose. A POSITA seeking to implement Pristash’s illuminator in an LCD would have been motivated to consult prior art like Suzawa for a known and effective method of housing the assembly. The stated benefits in Suzawa—preventing light leakage, improving illumination uniformity, and increasing efficiency—would have provided a strong motivation to enclose Pristash’s panel in Suzawa’s reflective tray.
    • Expectation of Success: The combination was argued to be a predictable application of known technologies. Integrating a known illuminator (Pristash) into a known housing structure (Suzawa) for use in their shared field of application would lead to the expected, successful result of an efficient backlight assembly.

4. Key Claim Construction Positions

  • "deformities" (claim 1): 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 proposed construction was based on an express definition provided directly in the specification of the ’816 patent.

5. Relief Requested

  • Petitioner requests the institution of an inter partes review and cancellation of claims 1, 3, and 4 of Patent 8,215,816 as unpatentable.