PTAB

IPR2019-00091

HTC Corporation v. Lemaire Illumination Technologies, LLC

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1. Case Identification

2. Patent Overview

  • Title: Illumination Source with Color-Changing LED
  • Brief Description: The ’390 patent relates to an illumination system that uses light-emitting diodes (LEDs) whose output color changes based on the level of driving current supplied. The patent describes using well-known control techniques, such as adjusting the height (amplitude) of electrical pulses to control the LED’s color and adjusting the width or frequency of the pulses to control the LED’s brightness.

3. Grounds for Unpatentability

Ground 1: Claims 19 and 22 are obvious over Kaelin

  • Prior Art Relied Upon: Kaelin (Patent 3,909,788)
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Kaelin taught all elements of independent claim 19. Kaelin disclosed an illumination source with a color-changing LED (specifically, a Gallium Phosphide LED from Bowmar Canada) whose color changed with current. Kaelin’s control circuit adjusted the pulse height by selecting one of three different current levels to produce red, green, or yellow light, thereby controlling the color spectrum. The same circuit used pulse width modulation to control the “apparent brightness” of the LED, which corresponds to the claimed “LED on-time proportion.” Petitioner contended the claimed “housing” was implicitly obvious, as a POSITA would understand that an LED display array requires a housing to be a complete, functional device.
    • Motivation to Combine (for §103 grounds): This ground is based on a single reference.
    • Expectation of Success (for §103 grounds): This ground is based on a single reference.

Ground 2: Claims 19 and 22 are obvious over Kaelin in view of Mueller

  • Prior Art Relied Upon: Kaelin (Patent 3,909,788), Mueller (Patent 6,016,038)
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground supplemented the Kaelin-only argument by asserting that Mueller explicitly taught the "housing" limitation. Mueller disclosed a complete LED lighting system and provided detailed figures showing an exploded view of its housing, designed to contain an LED array. The remaining limitations concerning a color-changing LED controlled by pulse height and pulse width were taught by Kaelin, as established in Ground 1.
    • Motivation to Combine (for §103 grounds): A POSITA would combine the references as they address the analogous art of LED control circuits. A POSITA seeking to implement Kaelin’s LED display would have been motivated to use a standard housing, as taught by Mueller, to create a finished product. Mueller encouraged using off-the-shelf components and different LED types, which would have suggested to a POSITA that Kaelin’s commercially available, color-changing LED was a suitable component for Mueller’s system.
    • Expectation of Success (for §103 grounds): A POSITA would have had a high expectation of success because combining Kaelin's control circuitry with Mueller's physical housing is a simple and predictable mechanical integration.

Ground 3: Claims 9 and 20 are obvious over Kaelin and Mueller in view of Okino

  • Prior Art Relied Upon: Kaelin (Patent 3,909,788), Mueller (Patent 6,016,038), and Okino (Patent 4,847,680)

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground built upon the Kaelin/Mueller combination to address dependent claims 9 and 20. Okino taught a camera system with an adjustable illumination source that used a feedback loop from a colorimetric sensor to measure color balance. This feedback was used to adjust the light source's hue for optimal image capture. Petitioner argued that Okino’s disclosure of a camera and a colorimetric feedback loop taught the "video camera imaging device" limitation of claim 20 and the "feedback signal" limitation of claim 9.
    • Motivation to Combine (for §103 grounds): A POSITA would combine Okino with the Kaelin/Mueller system because all three references are in the analogous field of controlling illumination sources. A POSITA would be motivated to incorporate Okino's color feedback control into the LED system of Kaelin/Mueller to enable automatic white balancing for a camera, thereby improving image quality. Updating Okino’s older light source with a more efficient and portable LED system would have been a logical and desirable improvement.
    • Expectation of Success (for §103 grounds): Success would be expected, as applying a known feedback control method from Okino to a known adjustable LED light source from Kaelin/Mueller was a well-understood design choice for improving camera performance.

  • Additional Grounds: Petitioner asserted additional obviousness challenges against the remaining dependent claims. These grounds relied on combinations of the core references with Hochstein (Patent 5,783,909) and Kitajima (Patent 5,808,681). Hochstein was used to teach adjusting pulse frequency to control LED on-time proportion (claim 23) and to compensate for brightness changes due to temperature or aging. Kitajima was used to teach deriving a color balance feedback signal directly from a CCD imaging device’s output signal, eliminating the need for a separate colorimetric sensor (claims 7, 8, 17, 18).

4. Key Claim Construction Positions

  • Petitioner proposed a specific construction for the term “LED on-time proportion” (claim 19). It argued that while the term might ordinarily refer to duty cycle or pulse width, the ’390 patent’s specification and dependent claims (e.g., claim 21 reciting pulse frequency adjustment) required a broader construction that also encompasses pulse frequency. This construction was critical to the obviousness grounds that relied on Hochstein's teaching of frequency modulation for brightness control.

5. Key Technical Contentions (Beyond Claim Construction)

  • A central technical contention was that the ’390 patent claimed nothing more than the application of fundamental and well-known electrical engineering principles to a known phenomenon. Petitioner argued that pulse amplitude modulation (to control current/voltage), pulse width modulation, and pulse frequency modulation were basic, ubiquitous techniques. Therefore, a POSITA would have found it obvious to apply these standard control methods to any LED known to change color with current, rendering the claimed invention a predictable combination of prior art elements.

6. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 7-10, 17-23, and 40 of Patent 6,488,390 as unpatentable under 35 U.S.C. §103.