PTAB

IPR2025-01537

Hisense USA Corp v. Light Guide Innovations LLC

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Light Source Apparatus and Liquid Crystal Display
  • Brief Description: The ’415 patent discloses a light source apparatus, such as an LCD backlight, composed of modular LED bars. Each bar comprises multiple module substrates with LEDs, which are interconnected by connecting substrates, including a termination substrate that creates a closed-loop circuit.

3. Grounds for Unpatentability

Ground 1: Obviousness over Roberts - Claims 1-2, 7-8, and 11 are obvious over Roberts.

  • Prior Art Relied Upon: Roberts (Application # 2007/0247414).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Roberts taught every limitation of independent claim 1. Roberts disclosed a lighting panel with light bar assemblies, where each assembly was made of multiple "lighting tiles" (module substrates) with connecting terminals at both ends and LEDs on their surface. Petitioner contended that Roberts' "edge connectors" were intermediate connecting substrates, and its "loopback connector" was a termination connecting substrate used to create a "closed-loop circuit" for independent control of LED strings. Dependent claims were also allegedly taught, as Roberts disclosed single- or multi-layer printed circuit boards (claim 8) and a reflective white paint on the substrate surface (claim 11).
    • Motivation to Combine (for §103 grounds): Not applicable as this ground relies on a single reference. Petitioner argued Roberts alone renders the claims obvious.
    • Expectation of Success (for §103 grounds): Not applicable.

Ground 2: Obviousness over Roberts in view of Liu - Claims 12 and 15 are obvious over Roberts and Liu.

  • Prior Art Relied Upon: Roberts (Application # 2007/0247414) and Liu (Application # 2006/0187660).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Roberts taught all limitations of claims 12 and 15 except for a "housing comprising a receiving groove." Liu was cited as teaching this missing element, disclosing a conventional method for securing lighting units to a backboard (housing) using rigid boards that form a receiving groove. The combination allegedly rendered claim 12 obvious, with claim 15 depending thereon.
    • Motivation to Combine (for §103 grounds): Petitioner argued a person of ordinary skill in the art (POSITA) would combine Liu's simple and effective mounting solution with Roberts' modular light bar system. Roberts disclosed its system for use as an LCD backlight but did not specify a mounting method. A POSITA would have looked to conventional methods like Liu's to simplify assembly, reduce parts, and improve thermal dissipation.
    • Expectation of Success (for §103 grounds): The combination would have been straightforward, as it involved applying a conventional mechanical fastening technique to Roberts' electrical light bar assembly.

Ground 3: Obviousness over Roberts in view of Karlicek - Claims 1-8 and 11 are obvious over Roberts and Karlicek.

  • Prior Art Relied Upon: Roberts (Application # 2007/0247414) and Karlicek (Application # 2003/0193789).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground was presented as an alternative to Ground 1. Petitioner argued that while Roberts disclosed connecting its light bars to an external driver, it lacked specific implementation details. Karlicek allegedly supplied these details, disclosing standardized "interconnecting elements" and a "terminating element" (claim 3) for connecting modular LED substrates to each other and to an external voltage source (claim 5).
    • Motivation to Combine (for §103 grounds): A POSITA would combine Karlicek’s modular and standardized connector system with Roberts’ modular light bars to create a more manufacturable and robust product. Karlicek's approach directly addressed the need in Roberts for a practical way to implement the inter-substrate and power connections, aligning with Roberts' overall modular design goal.
    • Expectation of Success (for §103 grounds): A POSITA would have expected success because Karlicek’s connectors were designed for the same purpose—interconnecting modular LED boards in series—and would be a predictable solution for implementing Roberts’ system.

  • Additional Grounds: Petitioner asserted additional obviousness challenges, including:

    • Claims 12-15 as obvious over Roberts, Karlicek, and Liu.
    • Claim 9 as obvious over Roberts in view of Nishida (disclosing multi-copper layer PCBs with silver plating for thermal management).
    • Claim 10 as obvious over Roberts in view of Newman (disclosing test pad terminals for testing LED chips).
    • Claims 16-18 as obvious over Roberts in view of Liu, Karlicek, and Hsiao (disclosing the conventional arrangement of a light unit disposed below a liquid crystal panel).

4. Relief Requested

  • Petitioner requests institution of an inter partes review (IPR) and cancellation of claims 1-18 of the ’415 patent as unpatentable.