Home Depot USA Inc v. Lynk Labs Inc

1. Case Identification

• Case #: IPR2022-00143
• Patent #: 10,932,341
• Filed: November 24, 2021
• Petitioner(s): Home Depot U.S.A., Inc.
• Patent Owner(s): Lynk Labs, Inc.
• Challenged Claims: 1-3, 5, 7-10, 12, 14-17, and 19

2. Patent Overview

• Title: Multi-Voltage and Multi-Brightness LED Lighting Devices and Methods of Using Same
• Brief Description: The ’341 patent describes an LED lighting device that includes at least two distinct LED circuits. The device is configured for either multi-brightness or multi-voltage operation by using a switch to control the power supplied to the different LED circuits.

3. Grounds for Unpatentability

Ground 1: Anticipation over Bruning - Claims 1, 3, 5, 7-8, 10, 12, 14-15, 17, and 19 are anticipated under 35 U.S.C. §102 by Bruning.

• Prior Art Relied Upon: Bruning (Application # 2002/0070914).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Bruning, which discloses a control and drive circuit for an LED display backlight, teaches every limitation of the challenged claims. Bruning describes a device with multiple LED sub-array circuits (e.g., red, green, and blue circuits) that emit different colors. Petitioner asserted that Bruning’s transistor switch (Q1) and its associated "panel light setting" user control constitute the claimed "switch." This switch is capable of switching a voltage level input to the LED circuits by controlling the duty cycle of Q1, which in turn adjusts the voltage applied to each LED sub-array and consequently changes their light output (brightness). Bruning’s device is also configured to connect to an AC power source.
  • Key Aspects: The core of this ground is that Bruning’s detailed description of a user-controllable circuit for adjusting LED backlight voltage and intensity directly maps onto the elements of the independent claims.

Ground 2: Obviousness over Bruning in view of Kabel - Claims 1-3, 5, 7-10, 12, 14-17, and 19 are obvious over Bruning in view of Kabel.

• Prior Art Relied Upon: Bruning (Application # 2002/0070914) and Kabel (Application # 2004/0164948).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground was presented as an alternative to Ground 1, addressing the Patent Owner's potentially narrow construction of "switch" as a physical, user-actuatable device. Petitioner argued that while Bruning discloses the overall system, it does not explicitly detail the physical implementation of its "panel light setting" control. Kabel remedies this by disclosing a conventional, "manually-activatable slider bar" as a user interface for adjusting the brightness of an LED backlight on a laptop display. The combination therefore teaches a multi-circuit LED system (Bruning) with a user-operable physical switch having at least two positions (Kabel) for adjusting light output.
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine these references to implement Bruning's user control with a well-known and conventional physical interface taught by Kabel. Given the similarities of the systems (both concerning LED backlights for LCDs), a POSITA would be motivated to look to analogous art like Kabel for known implementation details for user brightness controls.
  • Expectation of Success: A POSITA would have a high expectation of success, as the combination involves integrating a standard user interface (a slider switch) into a control circuit to perform its well-understood function of adjusting brightness.

Ground 3: Obviousness over Dowling in view of Mueller - Claims 1-2, 5, 7-9, 12, 14-16, and 19 are obvious over Dowling in view of Mueller.

• Prior Art Relied Upon: Dowling (Application # 2002/0048169) and Mueller (Patent 6,016,038).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner contended that Dowling discloses a multi-colored LED lighting device (e.g., a light bulb) with multiple, independently controllable LED circuits (red, green, blue) and a user-operable "two-way switch" to select different color-changing modes. This switch allows a user to turn individual LED circuits on and off, thereby changing the light output. To satisfy the limitation of each circuit having at least two LEDs in series or parallel, Petitioner pointed to Mueller, which Dowling expressly incorporates by reference. Mueller teaches implementing LED circuits using serial/parallel arrays to improve reliability.
  • Motivation to Combine: The motivation was explicit, as Dowling twice incorporates Mueller by reference and teaches that Mueller’s drive circuitry and color-mixing techniques should be used. Furthermore, the references share common inventors and were assigned to the same company, strengthening the rationale that a POSITA would read them together. A POSITA would also be motivated to implement Dowling’s power converter using the specific AC-to-DC transformer and rectifier circuits taught by Mueller to provide the requisite power for the LEDs.
  • Expectation of Success: A POSITA would have a reasonable expectation of success because Dowling directly instructs the use of Mueller’s established techniques. The combination involves applying fundamental, predictable electronic concepts for powering and controlling LED circuits as taught by Mueller to the system disclosed in Dowling.

4. Key Claim Construction Positions

• "switch": Petitioner argued the term should be given its plain and ordinary meaning, which does not require it to be operated by an "end user" or for the specific "purpose" of changing light output. This construction is broad enough to cover transistors and other circuit components. This position counters the Patent Owner’s proposed narrow construction, which Petitioner contended improperly imports limitations from the specification and would exclude embodiments.
• "selectable by a user switching the switch": Petitioner argued this phrase requires no construction beyond its ordinary meaning and does not require the user action to be "direct." This was intended to ensure that switches operated indirectly through a controller (as common in the art) fall within the scope of the claims.

5. Arguments Regarding Discretionary Denial

• Petitioner argued extensively that discretionary denial under Fintiv would be improper. The parallel district court litigation was in its early stages, with a tentative trial date more than a year away and likely to be postponed. Petitioner also stipulated that it would not pursue the same invalidity grounds in district court if the IPR was instituted, mitigating concerns of issue overlap. Petitioner also argued against denial under §325(d), asserting the examiner made clear errors during prosecution. Specifically, the examiner failed to consider the most relevant prior art (Bruning and Kabel) and allowed the claims based on a misunderstanding that an amendment had not broadened them, when in fact it had.

6. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-3, 5, 7-10, 12, 14-17, and 19 of the ’341 patent as unpatentable.