LED Apogee LLC v. STMicroelectronics Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: LED Apogee LLC (Delaware)
  • Defendant: STMicroelectronics, Inc. (Delaware)
  • Plaintiff’s Counsel: Rabicoff Law LLC
• Case Identification: LED Apogee LLC v. STMicroelectronics, Inc., 6:24-cv-00027, W.D. Tex., 01/16/2024
• Venue Allegations: Venue is alleged to be proper in the Western District of Texas because the Defendant maintains an established place of business in the District and has allegedly committed acts of patent infringement there.
• Core Dispute: Plaintiff alleges that certain of Defendant's semiconductor products infringe a patent related to methods for driving light-emitting diodes (LEDs).
• Technical Context: The lawsuit concerns the field of electronic driver circuits for LEDs, a technology fundamental to lighting, displays, and consumer electronics where power efficiency is a critical design parameter.
• Key Procedural History: The complaint does not mention any prior litigation, inter partes review (IPR) proceedings, or licensing history related to the patent-in-suit. The Plaintiff is identified as the assignee of the patent.

Case Timeline

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 6,982,527 - Method for driving light emitting diode

• Patent Identification: U.S. Patent No. 6,982,527, Method for driving light emitting diode, issued January 3, 2006 (the "’527 Patent").

The Invention Explained

• Problem Addressed: The patent’s background section describes two primary drawbacks with prior art LED driver circuits that use conventional charge pumps. First, their efficiency is inherently limited by the input voltage. Second, when driving modern LEDs (like white or blue LEDs) that have a variable forward voltage, a fixed-voltage driver circuit results in significant excess power loss, which is dissipated as heat (Compl., Ex. 1, ’527 Patent, col. 1:12-49).
• The Patented Solution: The invention proposes a method to improve efficiency by dynamically adjusting the voltage supplied to the LED. Instead of a fixed output voltage, the circuit uses an inductive charge pump to increase the input voltage to a current mirror. Crucially, it then uses the input of the LED itself as a "voltage feedback point" to maintain a constant, minimal voltage difference across the current mirror's output stage. This feedback mechanism ensures the driving voltage is only slightly higher than what the LED requires, thereby minimizing the power wasted as heat (Compl., Ex. 1, ’527 Patent, Abstract; col. 4:3-20; Fig. 4).
• Technical Importance: By actively regulating the driver voltage based on the LED's own characteristics, the method aimed to create more power-efficient drivers, a key consideration for battery-powered devices and reducing thermal management challenges in electronic systems (Compl., Ex. 1, ’527 Patent, col. 1:50-54).

Key Claims at a Glance

• The complaint alleges infringement of "one or more claims" and references "Exemplary '527 Patent Claims" in an attached Exhibit 2, which was not publicly filed with the complaint (Compl. ¶¶11, 16). Independent claim 1 is representative of the core invention.
• The essential elements of independent claim 1 include:
  • providing a control terminal voltage of said current mirror as a reference voltage;
  • increasing a voltage of an input of said current mirror and providing an input of said light emitting diode as a voltage feedback point for keeping a constant voltage difference between said input and said output of said current mirror; and
  • driving said light emitting diode by a voltage at said output of said current mirror.
• The complaint does not explicitly reserve the right to assert dependent claims, but refers generally to "one or more claims" (Compl. ¶11).

III. The Accused Instrumentality

Product Identification

• The complaint does not identify any specific accused products by name. It refers generally to "Exemplary Defendant Products" that are purportedly identified in charts within the unfiled Exhibit 2 (Compl. ¶11).

Functionality and Market Context

• The complaint alleges that Defendant makes, uses, sells, and imports products that infringe the ’527 Patent (Compl. ¶11). Given the nature of the patent and the Defendant's business as a semiconductor manufacturer, the accused products are likely integrated circuits such as LED drivers or power management ICs that incorporate LED driving functionality. The complaint does not provide sufficient detail for analysis of the accused products' specific functionality or market positioning.

IV. Analysis of Infringement Allegations

The complaint alleges that infringement details are provided in claim charts in an attached Exhibit 2 (Compl. ¶¶16-17). As this exhibit was not filed with the complaint, a detailed element-by-element analysis is not possible. The complaint’s narrative theory is that the "Exemplary Defendant Products practice the technology claimed by the '527 Patent" and "satisfy all elements of the Exemplary '527 Patent Claims" (Compl. ¶16). Without the specific product details and claim charts, it is not possible to identify potential points of contention in the infringement analysis.

No probative visual evidence provided in complaint.

V. Key Claim Terms for Construction

• The Term: "voltage feedback point"

• Context and Importance: This term is central to the novelty of the invention. The infringement analysis will depend on whether the accused devices use a "feedback point" that corresponds to the patent's description. Practitioners may focus on this term because the claimed location—"an input of said light emitting diode"—is the specific mechanism for achieving the invention's efficiency gains.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The claims do not specify the precise circuitry used to establish the feedback point, which may support an interpretation covering various technical implementations that achieve the same function.
  • Evidence for a Narrower Interpretation: The specification consistently links this feedback point directly to the input nodes of the LEDs themselves (e.g., nodes A42, A43, A44 in Fig. 4) ('527 Patent, col. 4:14-20). The use of the definite article "an input of said light emitting diode" could be argued to limit the scope to a direct connection rather than a more indirect sense of the LED's operating state ('527 Patent, col. 5:12-14).

• The Term: "keeping a constant voltage difference"

• Context and Importance: This functional language defines the outcome of the feedback loop. Whether the accused devices perform this function will be a critical infringement question.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: A party could argue "constant" should be understood in the practical context of an analog circuit, meaning "substantially constant" or "regulated to be within a target range," rather than mathematically invariant.
  • Evidence for a Narrower Interpretation: The patent contrasts the invention with the "excess power loss" of the prior art, which arose from a variable voltage difference ('527 Patent, col. 1:42-49). This purpose—to fix the power loss equation "PLEDLOSS=ILED*VX" by fixing "VX"—may support an interpretation that requires a more tightly regulated and stable voltage differential ('527 Patent, col. 4:34-37).

VI. Other Allegations

• Indirect Infringement: The complaint alleges induced infringement, stating that Defendant distributes "product literature and website materials inducing end users and others to use its products in the customary and intended manner that infringes the '527 Patent" (Compl. ¶14). The specific content of this literature is purportedly referenced in Exhibit 2 (Compl. ¶14).
• Willful Infringement: The willfulness allegation is based on post-suit conduct. The complaint asserts that the service of the complaint itself provides "actual knowledge of infringement" and that Defendant’s continued infringing activities thereafter are willful (Compl. ¶¶13-14).

VII. Analyst’s Conclusion: Key Questions for the Case

Based on the complaint, the litigation will likely center on the following key questions:

1. A primary evidentiary question will be which specific STMicroelectronics products are identified as the "Exemplary Defendant Products" and whether discovery will show that their internal circuitry in fact implements the feedback mechanism described in the patent.
2. A core issue will be one of claim construction: Can the term "voltage feedback point", as described in the patent, be construed to read on the specific circuit architecture of the accused products once they are identified?
3. A key infringement question will be functional: Assuming a feedback mechanism exists in the accused products, does it operate to achieve the claimed functional result of "keeping a constant voltage difference" between the input and output of the current mirror, as that phrase is construed by the court?