Hisense USA Corp v. Brightplus Ventures LLC

1. Case Identification

• Case #: IPR2023-01412
• Patent #: 8,330,710
• Filed: September 15, 2023
• Petitioner(s): Hisense USA Corporation
• Patent Owner(s): Brightplus Ventures LLC
• Challenged Claims: 1-2, 5, 11-13, 16-17, 47-48

2. Patent Overview

• Title: Systems and Methods for Controlling a Solid State Lighting Panel
• Brief Description: The ’710 patent relates to lighting systems, such as backlights for displays, that include a plurality of strings of solid-state lighting devices (e.g., LEDs), a current supply circuit, and a control system. The control system incorporates a firing logic to determine a specific firing order for the plurality of strings to control illumination.

3. Grounds for Unpatentability

Ground 1: Obviousness over Shteynberg, Arai, and Zhang - Claims 1-2, 5, 12, and 16-17 are obvious over Shteynberg in view of Arai and Zhang.

• Prior Art Relied Upon: Shteynberg (Application # 2008/0116818), Arai (Application # 2007/0121320), and Zhang (CN 1750732).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Shteynberg taught the foundational system of independent claim 1, including a plurality of LED strings, a power converter, a multiplexer for selective control, and a controller that receives input. To the extent Shteynberg’s arrangement of LED strings was insufficient, Arai was cited for explicitly teaching a two-dimensional arrangement of LED strings on rectangular bars. For the "firing logic" limitation, Petitioner contended that Zhang taught a rule-based process for determining a "non-spatially-sequential" firing order of backlight modules to mitigate brightness non-uniformity. Dependent claims were addressed by mapping feedback sensors in Shteynberg (claim 12) and the bar-like structures in Arai (claim 5).
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine these references to achieve predictable benefits. A POSITA would modify Shteynberg's system with Arai's efficient two-dimensional LED layout to achieve high luminance on large displays. Further, a POSITA would incorporate Zhang's non-spatially-sequential firing logic into this improved system to solve the known problem of brightness non-uniformity.
  • Expectation of Success: Petitioner asserted a high expectation of success because all three references are in the same field of endeavor (display backlighting) and the combination involved applying known techniques to solve known problems for predictable results.

Ground 2: Obviousness over Shteynberg, Arai, Zhang, and Kobori - Claim 11 is obvious over the combination of Shteynberg, Arai, and Zhang in view of Kobori.

• Prior Art Relied Upon: Shteynberg (Application # 2008/0116818), Arai (Application # 2007/0121320), Zhang (CN 1750732), and Kobori (Application # 2006/0139954).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground built upon the combination in Ground 1 to address dependent claim 11, which required the firing logic to comprise "random logic." Petitioner argued that Kobori taught the motivation and means to implement such logic. Kobori explicitly addressed improving luminance uniformity by "arbitrarily changing the PWM interval, the number of times, the phase for each LED so as to diversify the ON/OFF relationship." Petitioner asserted this teaching of arbitrarily changing the ON/OFF sequence was equivalent to the claimed "random logic."
  • Motivation to Combine: A POSITA, having already combined Shteynberg, Arai, and Zhang, would be motivated to further incorporate Kobori's teachings to improve luminance uniformity, a benefit explicitly described in Kobori.
  • Expectation of Success: Incorporating a randomizing firing order into a known controllable LED system was argued to be a straightforward modification for a POSITA with a high likelihood of achieving the desired improvement in display uniformity.

Ground 3: Obviousness over Shteynberg, Arai, and Lee - Claims 47-48 are obvious over Shteynberg in view of Arai and Lee.

• Prior Art Relied Upon: Shteynberg (Application # 2008/0116818), Arai (Application # 2007/0121320), and Lee (Application # 2007/0013647).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground challenged method claims 47 and 48, which recite supplying pulsed drive currents to a plurality of groups of strings. While Shteynberg and Arai provided the base method of controlling arranged LED strings, Petitioner argued Lee taught organizing LED strings into distinct groups (e.g., separate red, green, and blue string groups) that are electrically connected via combinations of series and parallel connections. Lee disclosed this structure to address issues of excessive driving voltage and non-uniform white light.
  • Motivation to Combine: A POSITA would be motivated to modify the lighting system and method of Shteynberg/Arai to incorporate Lee's string group architecture. The motivation was to solve the well-known problems of requiring excessive driving voltage and achieving uniform white light, which were the express goals of the Lee reference.
  • Expectation of Success: Petitioner contended that combining these known circuit design principles to enhance a standard LED backlight system would have been a predictable endeavor for a POSITA.

• Additional Grounds: Petitioner asserted additional obviousness challenges based on combinations substituting Kawabata (Application # 2003/0016205) for Zhang to teach a non-spatially-sequential firing order. These grounds included challenges to claims 1-2, 5, 12, and 16-17 over Shteynberg/Arai/Kawabata; claim 11 over Shteynberg/Arai/Kawabata/Kobori; and claim 13 over Shteynberg/Arai/Kawabata/Lee.

4. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under 35 U.S.C. §314(a) based on the Fintiv factors was inappropriate. The co-pending district court litigation was asserted to be in its early stages, with no trial date set, minimal investment by the parties, and infringement contentions only recently served. Petitioner also noted that the challenged claims in the inter partes review (IPR) did not completely overlap with the claims asserted in the litigation.
• Petitioner further contended that denial under 35 U.S.C. §325(d) was unwarranted because none of the prior art references relied upon in the petition were previously presented to or considered by the USPTO during the prosecution of the ’710 patent.

5. Relief Requested

• Petitioner requested the institution of an IPR and the cancellation of claims 1-2, 5, 11-13, 16-17, and 47-48 of the ’710 patent as unpatentable.