Feit Electric Company, Inc. v. Philips Lighting Holding B.V.

1. Case Identification

• Case #: IPR2018-00921
• Patent #: 6,586,890
• Filed: April 16, 2018
• Petitioner(s): Feit Electric Company, Inc.
• Patent Owner(s): Philips Lighting Holding B.V.
• Challenged Claims: 1, 7, 14, 22, and 30

2. Patent Overview

• Title: System and Method for Powering an LED Array
• Brief Description: The ’890 patent discloses a driver circuit for supplying power to LED arrays, particularly for automotive applications. The system uses pulse width modulation (PWM) and current feedback to maintain a nominal current, aiming to overcome prior art drawbacks like inefficiency and unpredictable light output caused by voltage fluctuations.

3. Grounds for Unpatentability

Ground 1: Obviousness over Biebl - Claims 1, 22, and 30 are obvious over Biebl.

• Prior Art Relied Upon: Biebl (Patent 6,400,101).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Biebl discloses all elements of the challenged claims. Biebl describes a "pulsed LED drive" circuit that addresses the same problems of power loss and fluctuating brightness in automotive LEDs as the ’890 patent. Biebl’s circuit includes an oscillator (sawtooth waveform generator and comparator) that generates a signal with two states, and a power supply (transistor T) that is responsive to this oscillating signal, supplying power to an LED array in a first state and not in a second state, directly mapping to the limitations of independent claim 1. For dependent claims 22 and 30, Petitioner asserted Biebl teaches monitoring for a fault (inoperability) by using a comparator to detect a voltage drop in the LED array and outputting a status signal.
  • Motivation to Combine (for §103 grounds): This ground is based on a single reference. The motivation for a person of ordinary skill in the art (POSITA) to arrive at the claimed invention was inherent, as Biebl addresses the same problems with the same type of solution.

Ground 2: Obviousness over Multiple References - Claims 7 and 14 are obvious over Biebl in view of the TI Book and Hamp.

• Prior Art Relied Upon: Biebl (Patent 6,400,101), TI Book (Texas Instruments Power Supply Control Products Data Book, 1999), and Hamp (Application # 2001/0033503).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that while Biebl teaches the functionality of the means-plus-function limitations in claims 7 and 14, the specific corresponding structures from the ’890 patent specification are rendered obvious by the combination. The ’890 patent identifies specific ICs like the Unitrode UCC2813 as the structure for its PWM control. Petitioner contended that the TI Book discloses this exact family of ICs, including their internal op-amps and reference signals. Further, while Biebl uses a simple semiconductor switch, Hamp discloses the specific DC-DC converter topologies (e.g., buck, boost) identified as the corresponding structure for the "means for supplying power" in the ’890 patent.
  • Motivation to Combine (for §103 grounds): A POSITA implementing Biebl’s circuit would be motivated to use a standard, off-the-shelf PWM controller like the UCC2813 described in the TI Book to reduce component count and simplify design. A POSITA would also be motivated to combine Hamp’s explicit teaching of using any DC-DC converter topology (buck, boost) with Biebl’s control methodology to create an efficient driver adaptable to different voltage supplies, a known design goal.
  • Expectation of Success (for §103 grounds): A POSITA would have a reasonable expectation of success, as the combination involves integrating well-documented, standard components for their known purposes.

Ground 3: Obviousness over Alternative References - Claim 7 is obvious over Hamp in view of LT1613.

• Prior Art Relied Upon: Hamp (Application # 2001/0033503) and LT1613 (Linear Technology LT1613 Data Sheet, 1997).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground presents an alternative theory. Petitioner asserted that Hamp alone teaches a DC-DC converter for driving an LED load with constant current. Crucially, Hamp’s circuit diagram explicitly identifies the use of an "LT1613" chip. A POSITA, guided by Hamp, would consult the LT1613 datasheet. That datasheet discloses a complete PWM architecture with all the structures corresponding to the means-plus-function elements of claim 7: a bandgap reference core ("means for generating a reference signal"), an op-amp comparator ("means for comparing"), and a PWM generator responsive to feedback ("means for modulating pulse width").
  • Motivation to Combine (for §103 grounds): The motivation to combine Hamp and the LT1613 datasheet was exceptionally strong, as Hamp explicitly directs a POSITA to use the LT1613 chip to build its circuit.
  • Expectation of Success (for §103 grounds): Success would be predictable, as it involves implementing a circuit with the specific component recommended by the primary reference.

• Additional Grounds: Petitioner asserted Ground 4, arguing claim 14 is obvious over Hamp in view of LT1613 and further in view of Biebl. This ground relies on the combination from Ground 3 and adds Biebl for its teaching of a "means for indicating the LED array is inoperable."

4. Key Claim Construction Positions

• Means-Plus-Function Terms (Claim 7): Petitioner argued that because claim 7 uses "means for" language, its scope is limited to the corresponding structures disclosed in the ’890 patent specification. Petitioner identified these structures as:
  • "means for sensing current": Resistors (e.g., R1A1, R1A2, R1A3).
  • "means for generating a reference signal": The internal reference of a specified PWM control IC (e.g., Unitrode UCC2813).
  • "means for comparing": The internal op-amp within the specified PWM control IC.
  • "means for supplying power": A DC/DC converter (e.g., buck, boost, or flyback).
• "inoperable" (Claims 14, 22, 30): Petitioner proposed construing the terms related to indicating inoperability (e.g., "LED array inoperable signal") as "providing a signal to alert an individual that the LED array is burnt out or disconnected." The corresponding structure in the ’890 patent was identified as a second op-amp (122) and a "BULB OUT" signal (124).

5. Arguments Regarding Discretionary Denial

• Estoppel: Petitioner argued that Patent Owner is estopped from asserting that Biebl lacks the features of the challenged claims. A prior IPR on the ’890 patent (IPR2015-01292) resulted in a final adverse judgment that claims 15 and 23 (the independent base claims for challenged claims 22 and 30) were anticipated by Biebl. Petitioner argued this creates both rule-based and collateral estoppel, precluding Patent Owner from re-litigating whether those features are present in Biebl.
• §314(a) Discretion (General Plastic Factors): Petitioner argued that the Board should not exercise its discretion to deny institution. This is the first petition filed by Feit Electric, it challenges claims not cancelled in the prior IPR (14, 22, 30), and it introduces new prior art and arguments (Hamp, LT1613, TI Book) that were not considered in the previous IPR or original prosecution.

6. Relief Requested

• Petitioner requested the institution of an inter partes review and the cancellation of claims 1, 7, 14, 22, and 30 of the ’890 patent as unpatentable.