PTAB

IPR2023-01411

Hisense USA Corp v. Brightplus Ventures LLC

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: LED Backlight System for LCD Displays
  • Brief Description: The ’705 patent describes an LED-based backlighting system for liquid crystal displays (LCDs). The system utilizes a waveguide element with a plurality of light entry regions and at least first and second light sources, such as LED strips, positioned to emit light into different entry regions of the waveguide.

3. Grounds for Unpatentability

Ground 1: Obviousness over Johnson - Claims 1, 2, 5, 6, 9, 11, 13, 14, 16, 17, 22, 28, 29, 31-34 are obvious over Johnson.

  • Prior Art Relied Upon: Johnson (Patent 6,608,614).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Johnson (’614 patent) discloses every limitation of independent claim 1. Johnson teaches an LCD backlight system comprising an LCD stack (panel) and a waveguide element with multiple light entry regions, specifically a first major surface and an edge surface. The ’614 patent further discloses a first light-emitting source (a first LED array arranged in a strip) positioned to emit light into the first major surface and a second light-emitting source (a second LED array arranged in a strip) positioned to emit light into the edge surface. Finally, Johnson discloses a common control circuit that is in electrical communication with both LED arrays to adjust brightness and chromaticity. Petitioner contended that Johnson’s disclosure renders the dependent claims obvious as well, teaching features like specific light colors, direct LEDs, linear arrangements, and application in various LCD devices.

Ground 2: Obviousness over Suzuki - Claims 1, 2, 5, 11, 13, 14, 16, 17, 32, and 34 are obvious over Suzuki.

  • Prior Art Relied Upon: Suzuki (Application # 2006/0220040).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Suzuki (’040 application) independently renders claim 1 and several dependent claims obvious. The ’040 application describes a surface illuminator for an LCD that includes a lightguide (waveguide) with a plurality of light entry regions (two opposing light entrance surfaces). Suzuki teaches positioning a first strip of LEDs along one light entrance surface and a second strip of LEDs along the opposing surface to serve as first and second light-emitting sources. The ’040 application also discloses a common LED driving circuit to control the LEDs, thereby meeting all limitations of claim 1. Petitioner further argued that Suzuki’s teachings of emitting white or single-color light, using linear LED arrangements, and its applicability to televisions (as Sharp, the assignee, is a known TV manufacturer) render the associated dependent claims obvious.

Ground 3: Obviousness over Suzuki in view of Fine - Claims 6, 22, 28, 29, 32, and 34 are obvious over Suzuki in view of Fine.

  • Prior Art Relied Upon: Suzuki (Application # 2006/0220040) and Fine (Patent 8,128,272).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground addressed dependent claims requiring features like "direct LEDs" and light sources positioned behind a central region of the LCD panel, which are not explicitly taught by Suzuki’s edge-lit system. Petitioner argued that Suzuki provides the base LCD system. Fine (’272 patent) teaches an illumination apparatus with LEDs embedded directly within the back portion of a waveguide material to provide direct, uniform backlighting. A POSITA would have found it obvious to modify Suzuki’s system by incorporating Fine’s embedded, direct-lighting LEDs.
    • Motivation to Combine: A POSITA would combine Suzuki and Fine to solve a known problem in the art: improving color uniformity and achieving a wider range of color reproducibility. Fine’s method of embedding LEDs is a known technique for modifying a base backlighting system like Suzuki's to achieve more uniform, direct illumination, which was a predictable improvement.
    • Expectation of Success: Because both references operate in the same field of LED backlighting for LCDs and address similar technical challenges, a POSITA would have had a reasonable expectation of successfully combining their teachings.

  • Additional Grounds: Petitioner asserted additional obviousness challenges, including for claims 32 and 33 over Johnson in view of Fine, based on applying the teachings of a secondary reference to a base system to achieve predictable results in known end-user devices like televisions and computer monitors.

4. Arguments Regarding Discretionary Denial

  • Petitioner argued that discretionary denial under 35 U.S.C. §314(a) based on Fintiv factors would be inappropriate. The core arguments were that the parallel district court litigation is in a very early stage, with no trial date scheduled and minimal investment by the court and parties. Petitioner contended that a Final Written Decision in the inter partes review (IPR) would issue well before any potential trial, and that the strong merits of the petition weigh in favor of institution to promote efficiency and simplify the parallel litigation.

5. Relief Requested

  • Petitioner requests institution of IPR and cancellation of claims 1, 2, 5, 6, 9, 11, 13, 14, 16, 17, 22, 28, 29, 31-34 of the ’705 patent as unpatentable.