LED Apogee LLC v. Texas Instruments Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: LED Apogee LLC (Delaware)
  • Defendant: Texas Instruments, Inc. (Delaware)
  • Plaintiff’s Counsel: Rabicoff Law LLC
• Case Identification: 2:24-cv-00996, E.D. Tex., 12/03/2024
• Venue Allegations: Plaintiff alleges venue is proper because Defendant has an established place of business in the district, has committed acts of patent infringement in the district, and Plaintiff has suffered harm there.
• Core Dispute: Plaintiff alleges that certain unidentified products of Defendant infringe a patent related to methods for driving light-emitting diodes (LEDs).
• Technical Context: The technology concerns electronic circuits designed to power LEDs efficiently, a critical component in applications ranging from backlighting for displays to general illumination.
• 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.

Case Timeline

Date	Event
2003-07-17	U.S. Patent 6,982,527 Priority Date
2006-01-03	U.S. Patent 6,982,527 Issued
2024-12-03	Complaint Filed

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

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

The Invention Explained

• Problem Addressed: The patent addresses the problem of "excess power loss" in prior art circuits that drive LEDs ('527 Patent, col. 1:45-48). Conventional designs often use a fixed high-voltage source to power an LED, but since the LED's required operating voltage (forward voltage) is lower, the excess voltage is dissipated as heat in the driver circuit, resulting in inefficiency ('527 Patent, col. 1:40-48).
• The Patented Solution: The invention proposes a method to minimize this power loss by dynamically managing the supply voltage. Instead of a fixed high voltage, it uses an inductive charge pumping circuit to increase the input voltage and, crucially, employs a feedback loop. This loop uses the input of the LED itself as a "voltage feedback point" to maintain a "constant voltage difference" between the input and output of a current mirror that drives the LED ('527 Patent, Abstract; col. 4:14-18). By keeping this voltage difference small and constant, the circuit supplies only the necessary voltage, significantly reducing wasted energy ('527 Patent, col. 4:32-35). Figure 4 illustrates this concept, showing the inductive charge pump (40) feeding a current mirror (41), with feedback taken from the nodes (A42, A43, A44) connected to the LEDs (D42, D43, D44).
• Technical Importance: This approach represents a method for creating more efficient, and therefore cooler and longer-lasting, LED driver circuits, which is critical for battery-powered devices and compact electronics where thermal management and power conservation are paramount ('527 Patent, col. 1:53-56).

Key Claims at a Glance

The complaint does not specify which claims are asserted, referring only to "one or more claims" and "the Exemplary '527 Patent Claims" (Compl. ¶11). The analysis below focuses on independent claim 1 as a representative claim.

• Independent Claim 1:
  • A method for driving a light emitting diode coupled to an output of a current mirror, comprising steps of:
  • 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.

III. The Accused Instrumentality

Product Identification

The complaint does not identify any accused products by name or model number. It refers to "Exemplary Defendant Products" that are purportedly identified in "charts incorporated into this Count" via an "Exhibit 2" (Compl. ¶¶ 11, 13). This exhibit was not provided with the complaint.

Functionality and Market Context

The complaint does not provide sufficient detail for analysis of the functionality or market context of the accused products. It makes only a conclusory allegation that the "Exemplary Defendant Products practice the technology claimed by the '527 Patent" (Compl. ¶13). No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint incorporates by reference infringement claim charts from an external "Exhibit 2," which was not included in the provided filing (Compl. ¶14). The complaint's narrative allegations are limited to stating that Defendant's unidentified products "satisfy all elements of the Exemplary '527 Patent Claims" (Compl. ¶13). As the charts are not available, a detailed element-by-element analysis is not possible.

Identified Points of Contention

Based on the patent claims and the general nature of the technology, the infringement analysis, once products are identified, may focus on several key questions:

• Technical Questions: A primary factual question will be whether the accused products’ driver circuits contain a "current mirror" and, if so, whether they employ a feedback mechanism as described in the patent. The specific method of feedback will be critical. For example, what evidence will show that the accused products use the input of the light emitting diode as the specific "voltage feedback point"?
• Scope Questions: The analysis may raise the question of whether the accused products' operation satisfies the limitation of "keeping a constant voltage difference" between the current mirror's input and output. Litigation may explore whether this requires a mathematically constant value or allows for operational variance, and what evidence from the accused devices demonstrates this function.

V. Key Claim Terms for Construction

"voltage feedback point"

• Context and Importance: This term is critical because Claim 1 specifically requires "providing an input of said light emitting diode as a voltage feedback point." Practitioners may focus on this term because the precise location and nature of the feedback signal are central to the claimed invention's method of improving efficiency. Defendant may argue its products use a different feedback source (e.g., a sense resistor, a different circuit node) that does not constitute an "input of said light emitting diode."
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The parties could argue the term should not be limited to a single physical connection, as the patent discloses embodiments with multiple LEDs arranged in parallel, where feedback is taken from "one of VA42, VA43 and VA44" ('527 Patent, col. 4:16-17).
  • Evidence for a Narrower Interpretation: The patent consistently illustrates this point as the direct input node to the LED (or bank of LEDs), as shown in Figure 4 where nodes A42, A43, and A44 are the specific feedback points and also the inputs to the LEDs D42, D43, and D44 ('527 Patent, Fig. 4). This could support a narrow construction limited to that specific circuit topology.

"keeping a constant voltage difference"

• Context and Importance: The novelty of the invention hinges on actively managing the voltage to maintain this constant difference, thereby reducing power loss. The meaning of "constant" will be central to the infringement analysis.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: A party might argue that "constant" should be understood in the context of an operating electronic circuit, meaning "substantially constant" or "regulated to be constant," rather than a mathematically perfect, unchanging value.
  • Evidence for a Narrower Interpretation: The specification explicitly states that "the voltage difference VX between Vout of the output and VA42 of the input of the current mirror 41 is fixed," which suggests an intentional and actively maintained state, not an incidental or fluctuating one ('527 Patent, col. 4:32-35). This language may support a narrower definition requiring a specific, regulated condition.

VI. Other Allegations

Indirect Infringement

The complaint makes no allegations of indirect or contributory infringement. It contains only a single count for "Direct Infringement" (Compl. ¶11).

Willful Infringement

The complaint does not contain an explicit allegation of willful infringement or a request for enhanced damages under 35 U.S.C. § 284 based on willfulness. It does request that the case be declared "exceptional" to recover attorney's fees under 35 U.S.C. § 285, but it does not plead any specific facts regarding pre- or post-suit knowledge of the patent to support such a finding (Compl. p. 4, ¶ E.i).

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

The initial phase of this litigation will likely revolve around fundamental pleading and discovery issues before reaching the core technical merits. The key questions for the case appear to be:

1. A primary evidentiary question: What specific Texas Instruments products are accused of infringement? The complaint's failure to identify any accused instrumentality or provide the referenced claim chart exhibit creates a significant ambiguity that must be resolved before any substantive analysis can occur.
2. A core issue of technical correspondence: Assuming products are identified, does their internal circuitry practice the specific method of Claim 1? The case will likely turn on whether the accused LED drivers employ a feedback loop that uses the LED's input as a "voltage feedback point" for the express purpose of "keeping a constant voltage difference" across a current mirror, or if they achieve efficiency through a different, non-infringing technical approach.
3. A central question of claim construction: Can the term "constant voltage difference," in the context of the patent's specification, be interpreted to read on the real-world operational characteristics of the accused products? The definition of this term will be critical in determining the scope of the claim and the boundary between practicing the invention and prior art.