PTAB

IPR2017-01744

LG Electronics Inc v. Lemaire Illumination Technologies LLC

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Petition
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1. Case Identification

2. Patent Overview

  • Title: COLOR-ADJUSTED CAMERA LIGHT AND METHOD
  • Brief Description: The ’390 patent discloses an LED illumination source having a control circuit that adjusts both the amount (brightness) and the color spectrum of the light output. The circuit supplies electrical pulses to the LEDs and adjusts the "on-time proportion" of the pulses to control brightness, while separately adjusting the "height" of the pulses to control the color spectrum.

3. Grounds for Unpatentability

Ground 1: Obviousness over Van Antwerp, Bosch, and Basrur - Claim 19 is obvious over Van Antwerp in view of Bosch and Basrur.

  • Prior Art Relied Upon: Van Antwerp (Patent 4,514,727), Bosch (Patent 5,373,387), and Basrur (Appl. Phys. Lett., Sep. 1997).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the prior art collectively discloses all elements of claim 19. Van Antwerp was asserted to teach an illumination source with LEDs on a housing and a control circuit that uses pulse width modulation (PWM) to "adjust an LED on-time proportion to control an amount of the output light," primarily to compensate for fluctuating battery voltage. For controlling color, Petitioner turned to Bosch, which teaches a dual-loop control circuit for a laser diode (argued to be analogous to an LED) that controls both average light output via PWM and light amplitude. This amplitude control, Petitioner asserted, was known to control color spectrum. The combination was further supported by Basrur, which explicitly teaches that adjusting pulse amplitude (current) and duration for Gallium Nitride LEDs directly controls and modifies their output color spectrum, including shifting blue light to ultraviolet.
    • Motivation to Combine: Petitioner argued a person of ordinary skill in the art (POSITA), seeking to design an LED illumination source with control over both brightness and color, would have been motivated to combine these references. A POSITA would start with a basic LED brightness control circuit like Van Antwerp's and look to solve the known problem of color variation. It would be obvious to look to analogous circuits, such as those for laser diodes, for more sophisticated control strategies. Bosch provided a clear roadmap for combining PWM (for brightness) with amplitude control. Petitioner contended it was routine to adapt such laser diode circuits to LEDs. A POSITA would then incorporate the specific teachings of Basrur, which confirms that pulse amplitude directly controls color in LEDs, to implement the color control functionality claimed in the ’390 patent. The references address the same technical problems in the same field and would combine to yield predictable results.
    • Expectation of Success: Petitioner asserted that a POSITA would have a reasonable expectation of success because combining known methods for brightness control (Van Antwerp's PWM) with known methods for amplitude/color control (Bosch and Basrur) involved applying established principles to achieve a predictable outcome.

4. Key Claim Construction Positions

Petitioner proposed constructions for key terms in claim 19, arguing they were critical to the obviousness analysis.

  • "to adjust an LED on-time proportion to control an amount of the output light": Petitioner argued that, to a POSITA, this phrase meant using a series of repeating on-and-off pulses (i.e., PWM) where the "on-time" is the period the DC supply is applied. Adjusting the fraction of on-time relative to the total pulse period (the duty cycle) would predictably increase or decrease the total amount of light output.
  • "Adjusts a height of the pulses to control a color spectrum of the LED output light": Petitioner adopted the construction from a prior Board decision involving the ’390 patent (IPR2013-00611), defining this limitation as to "[m]odify a height of multiple pulses, which results in modification to a color spectrum of the LED light output." Petitioner argued this construction was consistent with the teachings of Bosch and Basrur, where pulse amplitude (height) directly correlates to current and thus to the output color.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claim 19 of the ’390 patent as unpatentable.