PTAB

IPR2024-01130

BOE Technology Group Co Ltd v. Optronic Sciences LLC

Key Events

Petition

petition

Title: Backlight Package
Brief Description: The ’842 patent discloses a light-emitting diode (LED) backlight package for displays. The technology centers on mounting an LED module onto the side of a substantially L-shaped fastener, which is positioned adjacent to a light guiding plate.

Prior Art Relied Upon: Uekusa (Patent 6,927,424).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued that Uekusa discloses every element of the challenged claims. Uekusa's backlight assembly includes a light guiding plate ("optical wave-guide 55"), an L-shaped fastener ("body section 36" with an upright portion and a horizontal extension), and an LED (34) disposed on the fastener to emit light toward the plate. For claims 6 and 9, Petitioner asserted that Uekusa's metallic substrate electrodes (33a, 33b) inherently function as the claimed heat dissipating means as they are made of conductive material and would dissipate heat from the LED. For claim 4, Petitioner contended that Uekusa’s horizontal portion is vertically displaced from and overlaps the light guiding plate, satisfying the ordinary meaning of “extending above” the plate.

Prior Art Relied Upon: Uekusa (Patent 6,927,424) and Isoda (Patent 7,218,041).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner asserted that Uekusa teaches the fundamental backlight structure with an L-shaped fastener, as detailed in Ground 1. Isoda addresses the known problem of heat degradation in high-brightness LEDs by teaching the use of effective heat dissipation means, such as a plurality of heat-dissipating fins or plates attached to the LED device's circuit board.
- Motivation to Combine: A person of ordinary skill in the art (POSITA) would have been motivated to improve the thermal performance of Uekusa’s backlight, as increased brightness in LEDs generates significant heat, a well-known problem. Isoda expressly teaches using enhanced cooling structures like heat fins to solve this exact problem in similar LED applications. A POSITA would combine Isoda's heat dissipation teachings with Uekusa’s backlight design to improve device longevity and performance. The ’842 patent itself acknowledges that attaching heat sinks is a "typical" configuration.
- Expectation of Success: Combining a known heat dissipation solution (Isoda) with a standard backlight package (Uekusa) to address a known problem (heat) would have been a routine modification yielding the predictable result of improved thermal management.

Prior Art Relied Upon: Kurokawa (JP 2004-279262).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued that Kurokawa discloses a backlight package that meets all limitations of the challenged claims. Kurokawa describes an L-shaped fastener ("metal plate 71"), a light guiding plate (5), and LEDs (8) mounted on the fastener. For claims requiring a circuit board and heat dissipation, Petitioner argued that Kurokawa’s flexible printed wiring board (72) satisfies the circuit board limitation and that the metallic, bent fastener (metal plate 71) itself functions as the heat dissipating means by conducting heat away from the electronics mounted on the attached wiring board. Petitioner further asserted that the bent shape of the metal plate provides a plurality of surfaces for dissipation, satisfying constructions requiring plural plates.
Additional Grounds: Petitioner asserted additional obviousness challenges based on Uekusa in view of Applicant Admitted Prior Art (AAPA); Kurokawa alone; Kurokawa in view of Isoda; and anticipation and obviousness challenges based on Fukuta (Application # 2002/0047978).

"wherein the second portion extends above the light guiding plate" (claims 4, 7): Petitioner argued this term should be given its ordinary meaning. However, Petitioner noted that the ’842 patent’s only embodiment depicts the second portion below the light guiding plate. To account for this, Petitioner proposed an alternative construction of "above" as "displaced vertically from and overlapping a portion of the light guiding plate," contending that prior art references like Uekusa and Kurokawa satisfy this construction.
"heat dissipating means attached onto the surface of the circuit board for conducting a heat generated thereon" (claims 6, 9): Petitioner argued this is a means-plus-function limitation under 35 U.S.C. §112(f). Based on the specification, Petitioner contended the corresponding structure is "heat-dissipating plates (plural)," requiring more than one plate. This construction is central to arguments that prior art references with a single bent plate (e.g., Kurokawa) or conductive electrodes (e.g., Uekusa) meet the limitation by providing multiple surfaces or components for heat dissipation.

Petitioner argued that discretionary denial under §314(a) and the Fintiv factors is not warranted. The core arguments were that no trial date has been set in the parallel district court litigation, weighing against denial. Further, Petitioner asserted there is minimal issue overlap, as the litigation complaint asserts only one claim, whereas the IPR challenges seven claims. Petitioner also contended that the petition presents compelling evidence of unpatentability, which weighs strongly in favor of institution.

Petitioner requests institution of an inter partes review and cancellation of claims 3-9 of the ’842 patent as unpatentable.