LED Apogee LLC v. MediaTek Inc

I. Executive Summary and Procedural Information

• Case Name: LED Apogee LLC v. MediaTek Inc.
• Parties & Counsel:
  • Plaintiff: LED Apogee LLC (Delaware)
  • Defendant: MediaTek Inc. (Taiwan)
  • Plaintiff’s Counsel: Rabicoff Law LLC
• Case Identification: 6:24-cv-00023, W.D. Tex., 01/16/2024
• Venue Allegations: Plaintiff alleges venue is proper because Defendant is a foreign corporation.
• Core Dispute: Plaintiff alleges that Defendant infringes a patent related to methods for driving light-emitting diodes (LEDs) with improved power efficiency.
• Technical Context: The technology concerns electronic circuits that power and control LEDs, a critical component in applications ranging from mobile device backlights 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

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

U.S. Patent No. 6,982,527, "Method for driving light emitting diode," Issued January 3, 2006

• The Invention Explained:

  • Problem Addressed: The patent describes drawbacks in prior art circuits for driving LEDs, particularly white LEDs. Conventional charge pump circuits were said to have low efficiency, and when coupled with a current mirror, they could lead to "excess power loss" because the voltage supplied was often significantly higher than the voltage required by the LED. (’527 Patent, col. 1:27-48).
  • The Patented Solution: The invention proposes a method using an inductive charge pumping circuit to increase an input voltage supplied to a current mirror. A key feature is the use of the LED's own input as a "voltage feedback point." This feedback loop is designed to maintain a "constant voltage difference" between the input and output of the current mirror, which in turn drives the LED. This method aims to minimize the voltage drop across the mirror, thereby reducing power loss and improving efficiency. (’527 Patent, Abstract; col. 4:1-20).
  • Technical Importance: The described method sought to provide a more power-efficient solution for driving modern LEDs (e.g., white and blue LEDs), which were becoming ubiquitous in consumer electronics and required stable, efficient power management to maximize battery life and performance. (’527 Patent, col. 1:37-48).

• Key Claims at a Glance:

  • The complaint does not specify which claims are asserted, referring only to the "Exemplary ’527 Patent Claims" in a non-proffered exhibit (Compl. ¶11). Independent claim 1 is representative of the core invention.
  • Independent Claim 1:
    • 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 requests judgment that Defendant has infringed "one or more claims of the ’527 Patent" (Compl., Prayer for Relief ¶B).

III. The Accused Instrumentality

• Product Identification: The complaint does not specifically name any accused products or services in its text. It refers to "Exemplary Defendant Products" that are purportedly identified in charts within Exhibit 2. (Compl. ¶11, 16). This exhibit was not filed with the complaint.
• Functionality and Market Context: The complaint does not provide sufficient detail for analysis of the accused products' functionality or market context.

IV. Analysis of Infringement Allegations

The complaint alleges that infringement is detailed in claim charts attached as Exhibit 2, which was not provided with the initial filing (Compl. ¶16-17). The body of the complaint does not contain factual allegations describing how any specific product feature meets any claim limitation. Instead, it states that the "Exemplary Defendant Products incorporated in these charts satisfy all elements of the Exemplary '527 Patent Claims" (Compl. ¶16). No probative visual evidence provided in complaint.

• Identified Points of Contention:
  • Evidentiary Question: A threshold issue is the identification of the accused products and the specific circuitry within them that allegedly performs the claimed method. The complaint's reliance on an external, unfiled exhibit leaves this entirely open.
  • Technical Question: A likely point of dispute will be whether Defendant's products, presumably power management integrated circuits (PMICs) or systems-on-a-chip (SoCs), implement the precise feedback mechanism of claim 1. The analysis will question whether the accused circuits use the LED's input terminal as the specific "voltage feedback point" for the express purpose of "keeping a constant voltage difference" across the current mirror, or if they use different, more complex, or multi-purpose feedback schemes.

V. Key Claim Terms for Construction

• The Term: "voltage feedback point"

  • Context and Importance: This term is central to the novelty of the claimed control loop. The infringement analysis will depend on whether the accused circuitry uses the specific point defined in the patent for feedback, or another signal. Practitioners may focus on this term to determine if the claim is limited to the physical node at the LED's input or can cover any signal functionally representative of the LED's voltage.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Narrower Interpretation: The specification explicitly identifies "the nodes A42, A43 and A44 of the respective inputs of the white light emitting diodes D42, D43 and D44" as being "provided as voltage feedback points." (’527 Patent, col. 4:14-16, referencing Fig. 4). This directly ties the term to the physical input node of the diode.
    • Evidence for a Broader Interpretation: A party might argue that the term should be construed functionally to mean any circuit node that provides a voltage signal indicative of the LED's operational state for use in a feedback loop, even if not the direct input terminal.

• The Term: "constant voltage difference"

  • Context and Importance: This term defines the objective of the feedback loop and is critical for assessing both infringement and the patent's purported efficiency improvement. The dispute will likely center on the required degree of "constancy."
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Narrower Interpretation: The specification explains that the "voltage difference VX between Vout of the output and VA42 of the input of the current mirror 41 is fixed," which significantly decreases power loss. (’527 Patent, col. 3:31-34). This suggests the goal is to maintain a specific, predetermined, and stable voltage drop, not merely a generally regulated one.
    • Evidence for a Broader Interpretation: An opposing argument could be that in the context of analog circuits, "constant" does not mean mathematically invariant but rather regulated to be stable within a normal operating range, allowing for minor fluctuations inherent in circuit performance.

VI. Other Allegations

• Indirect Infringement: The complaint alleges induced infringement based on Defendant distributing "product literature and website materials" that allegedly instruct customers on using the accused products in an infringing manner (Compl. ¶14). Knowledge is alleged to arise "at least since being served by this Complaint" (Compl. ¶15).
• Willful Infringement: Willfulness is alleged based on post-suit conduct. The complaint asserts that the filing of the complaint provides Defendant with "actual knowledge of infringement" and that Defendant's continued alleged infringement thereafter is willful (Compl. ¶13-14). No pre-suit knowledge is alleged.

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

• A primary issue will be one of evidentiary sufficiency: given the complaint's complete reliance on an unfiled exhibit, a threshold question is what evidence Plaintiff will introduce to first identify the accused products and then map their internal circuit operations to the specific method steps of the asserted claims.
• The case will likely turn on a core question of technical implementation: does the accused circuitry in MediaTek’s products—if and when identified—employ the specific feedback topology required by the claims? Specifically, does it use the LED's direct input as a "voltage feedback point" for the sole stated purpose of maintaining a "constant voltage difference" across a current mirror, or does it achieve power regulation through a different, non-infringing mechanism?
• A third key issue will be one of claim scope: can the term "constant voltage difference," which underpins the patent's efficiency argument, be construed to read on the performance of modern, complex power management circuits that may regulate voltage dynamically rather than holding it to a fixed, "constant" differential?