PTAB

IPR2017-01261

Cree Inc v. OptoLum Inc

Log In
Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Light Emitting Diode Light Source
  • Brief Description: The ’028 patent discloses a light source using light-emitting diodes (LEDs) mounted on an elongate, thermally conductive member. This member, which can be a tubular structure, functions as a heat sink, and its cooling is enhanced by the flow of a heat transfer medium (e.g., air) through its interior.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 1, 19, and Dependents by Begemann

  • Prior Art Relied Upon: Begemann (Patent 6,220,722).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Begemann anticipates every limitation of independent claims 1 and 19. Begemann discloses an LED lamp with a tubular, hollow "gear column" connected to a multi-faced substrate and a lamp cap, which collectively form the claimed "elongate thermally conductive member." LEDs are mounted on the outer faces of the substrate. The hollow gear column contains a fan that circulates air, satisfying the limitation of conducting heat to a fluid contained by the member. Petitioner contended that the screw threads of the lamp cap and/or the edges of the pyramidal substrate constitute the claimed "heat dissipation protrusions." The dependent claims were also argued to be disclosed, as Begemann teaches the use of air as a fluid (claim 3), a tubular member (claim 5), a polygon cross-section via the substrate (claim 6), and white light LEDs (claim 16).
    • Key Aspects: This ground asserted that a single prior art reference teaches all elements of the key independent claims, forming the baseline for all subsequent obviousness arguments.

Ground 2: Obviousness of Claims 1 and Dependents over Begemann and English

  • Prior Art Relied Upon: Begemann (’722 patent), English (Patent 6,682,211).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground was presented as an alternative to Ground 1, assuming Begemann was found not to disclose "heat dissipation protrusions." English discloses a replaceable LED lamp capsule with a metal support structure for mounting LEDs. Crucially, English expressly teaches that its base portion "may include on an exterior side cooling fins or other heat dissipating structures" to enhance thermal conduction away from the LEDs.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSA) would combine English’s explicit teaching of adding external cooling fins with Begemann’s lamp design. Both references address the common problem of heat management in high-illumination LEDs. A POSA would apply the known solution from English (adding fins) to Begemann's elongate thermally conductive member to predictably enhance heat dissipation, improve lamp life, and increase light output.
    • Expectation of Success: The combination would have yielded predictable results. Adding cooling fins to a metal heat sink is a straightforward and well-understood mechanical modification for improving thermal performance, and Begemann already disclosed air circulation that would make such fins effective.

Ground 3: Obviousness of Claims 23-26 over Begemann, Arndt, and Asami

  • Prior Art Relied Upon: Begemann (’722 patent), Arndt (Patent 6,848,819), and Asami (Patent 4,296,539).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground challenged claims reciting that the thermally conductive member is an "extrusion," specifically an "aluminum extrusion." Begemann discloses the required tubular, polygon-shaped member but does not specify its manufacturing method. Arndt teaches that cooling members for LEDs can be fabricated from highly conductive metals like aluminum. Asami discloses a heat transfer tube with integral internal and external fins that is "easily formed by extrusion of aluminum alloy as a single integral unit."
    • Motivation to Combine: A POSA seeking to manufacture the lamp structure of Begemann would look to known, efficient manufacturing techniques. A POSA would combine the teachings by making Begemann’s gear column from aluminum (as suggested by Arndt) and forming it via extrusion (as taught by Asami). This combination was motivated by the desire to achieve ease of fabrication, reduce manufacturing costs, and integrally form heat fins for improved, predictable thermal performance.
    • Expectation of Success: The expectation of success was high because extruding aluminum is a well-known, reliable process for creating complex, finned profiles for heat sinks, directly addressing the design goals of the challenged patent.

  • Additional Grounds: Petitioner asserted numerous additional grounds. These included obviousness challenges to various claim sets based on combinations of Begemann with Verdes (Patent 6,425,678) to teach a simpler, uniform polygon-shaped vertical cylinder. Further grounds added English to these combinations to cure any perceived deficiency regarding heat dissipation protrusions.

4. Key Claim Construction Positions

Petitioner proposed constructions for several key terms under the Broadest Reasonable Interpretation standard, asserting they were critical to the invalidity analysis.

  • "Elongate": Construed as "having more length than width." This plain meaning was argued to be consistent with the specification and prosecution history.
  • "Thermally conductive member": Construed as a "structural unit that is thermally conductive." This construction was argued to encompass multi-part assemblies, like the gear column, substrate, and lamp cap in Begemann, rather than being limited to a single, monolithic piece of material.
  • "Heat dissipation protrusions": Construed as "protrusions that dissipate heat." Petitioner argued this broad, plain-meaning interpretation was appropriate and encompassed structures like screw threads and sharp edges, not just conventional "fins."

5. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1-3, 5-8, 13-16, and 19-29 of the ’028 patent as unpatentable.