DCT

2:24-cv-01077

Phenix Longhorn LLC v. Samsung Electronics Co Ltd

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:24-cv-01077, E.D. Tex., 05/29/2025
  • Venue Allegations: Plaintiff alleges venue is proper based on Defendants' sales of accused products in the district, a continuing presence, and requisite minimum contacts. For Defendant Samsung Electronics America, Inc., venue is additionally based on its alleged regular and established place of business in Plano, Texas.
  • Core Dispute: Plaintiff alleges that Defendants’ televisions, monitors, and displays infringe two patents related to programmable integrated circuits and methods for generating gamma reference voltages to control image quality in LCD panels.
  • Technical Context: The technology concerns electronic circuits that automate gamma correction in flat-panel displays, a critical function for achieving accurate color and contrast while streamlining manufacturing.
  • Key Procedural History: The complaint alleges that the validity of U.S. Patent No. 7,233,305 was upheld in an Inter Partes Review proceeding where the Patent Trial and Appeal Board denied institution. It also details extensive pre-suit technical and commercial interactions between Plaintiff's predecessor-in-interest, Alta Analog, Inc., and Samsung's Display Division from 2003 to 2012, which form the basis for allegations of pre-suit knowledge and willful infringement.

Case Timeline

Date Event
2003-06-11 '305 & '788 Patents Priority Date
2003-08-04 Alta's first meeting with Samsung engineers
2003-12-23 '305 Patent Application Filed
2007-05-01 '788 Patent Application Filed
2007-06-19 U.S. Patent No. 7,233,305 Issued
2009-07-07 U.S. Patent No. 7,557,788 Issued
2012-04-01 Samsung Display formed from Samsung Electronics' Display Division
2012-06 Alta allegedly provides datasheet marked with Asserted Patents to Samsung
2019-01-24 PTAB denies institution of Inter Partes Review on '305 Patent
2025-05-29 Complaint Filing Date

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

U.S. Patent No. 7,233,305 - "Gamma Reference Voltage Generator"

The Invention Explained

  • Problem Addressed: The patent’s background section describes the problem of compensating for manufacturing variations in Thin Film Transistor (TFT) flat panel displays ('305 Patent, col. 1:18-30). The conventional solution involved using "Select-On-Test Resistors," a manual, inflexible, and costly process that hindered automated assembly and testing of displays ('305 Patent, col. 1:31-40, 1:52-56).
  • The Patented Solution: The invention is a programmable integrated circuit that generates gamma correction reference voltages for an LCD ('305 Patent, Abstract). It stores these voltage values in non-volatile memory, allowing the settings to be retained without power and enabling automated calibration during manufacturing ('305 Patent, col. 2:16-29). The complaint includes a set of images demonstrating how different gamma correction values alter the curvature of light and dark tones in a picture (Compl. ¶62). The architecture, shown in Figure 2, uses dedicated gamma reference controllers (210, 220) to replace the cumbersome resistor ladders of the prior art.
  • Technical Importance: This integrated-circuit approach was designed to automate gamma adjustment, reduce manufacturing costs, and enable smaller, more efficient display panel designs ('305 Patent, col. 2:30-33).

Key Claims at a Glance

  • The complaint asserts infringement of at least Claim 1 (Compl. ¶122).
  • Independent Claim 1 of the ’305 Patent recites:
    • An integrated circuit for producing voltage signals on a plurality of outputs comprising:
    • a plurality of non-volatile storage cells;
    • circuits for programming coupled to a multiplexer for addressing and programming said storage cells, wherein the addressing is based on a plurality of inputs;
    • drivers connected to said storage cells and to the plurality of outputs; and
    • the plurality of inputs connected to said multiplexer for addressing said storage cells,
    • wherein said voltage signals are gamma reference voltage signals for determining actual driving voltages of columns of a display,
    • wherein said non-volatile storage cells are organized into two or more banks of cells wherein each bank contains a predetermined gamma reference voltage signal display condition; and
    • means to switch between the banks based on one or more external signals is provided on said integrated circuit.
  • The complaint states that SAMEX has infringed one or more claims of the patent (Compl. ¶118).

U.S. Patent No. 7,557,788 - "Gamma Reference Voltage Generator"

The Invention Explained

  • Problem Addressed: The '788 Patent, a continuation of the '305 Patent, addresses the same problem of inefficient and manual gamma correction in LCD manufacturing using "Select-On-Test Resistors" ('788 Patent, col. 1:30-49).
  • The Patented Solution: This patent claims a method for calibrating an LCD to a desired gamma curve ('788 Patent, Abstract). The method involves using an external optical sensor to test the display, varying the gamma reference voltages with a separate control circuit, using a predetermined algorithm to optimize those voltages, and then electronically storing the optimized values in the display's non-volatile gamma reference control circuitry ('788 Patent, col. 8:24-42). This automates the entire calibration process on the production line ('788 Patent, col. 7:9-20).
  • Technical Importance: The claimed method allows for the automation of panel calibration, enabling manufacturers to improve display quality and consistency while reducing manual labor and associated production costs ('788 Patent, col. 7:9-12).

Key Claims at a Glance

  • The complaint asserts infringement of at least Claim 1 (Compl. ¶152).
  • Independent Claim 1 of the ’788 Patent recites:
    • A method of calibrating a liquid crystal display to a desired gamma curve to compensate for panel to panel manufacturing variations comprising the steps:
    • a. providing said display with gamma reference control capability which is electrically reprogrammable and non-volatile;
    • b. testing said display with at least one sensor with optical input, wherein said sensor is separate from said display;
    • c. varying gamma reference voltage levels on columns of said display by a control circuit, where said control circuit is separate from said display;
    • d. optimizing said gamma reference voltage levels using means for executing a predetermined algorithm according to a predetermined criteria and data sensed by said at least one sensor, wherein said means for executing said predetermined algorithm is separate from said display to achieve the desired gamma curve; and
    • e. storing said gamma reference voltage levels in said gamma reference control capability.
  • The complaint states that SAMEX has infringed one or more claims of the patent (Compl. ¶148).

III. The Accused Instrumentality

Product Identification

The complaint accuses a wide range of Samsung-branded televisions, monitors, and displays manufactured by Defendant SAMEX and sold in the United States (Compl. ¶¶24, 86). Specific product families and models are listed in Tables A through F of the complaint (Compl. ¶¶97-112).

Functionality and Market Context

The accused products are alleged to incorporate gamma correction circuitry to control image quality on their LCD, LED, QLED, or OLED panels (Compl. ¶¶53-54, 111). The complaint categorizes the products based on their internal printed circuit board architecture: a "three-board design" with a separate timing controller ("T-con") board containing the gamma chip, a "two-board design" where T-con functionality is merged into the main board, and a "3-in-1 board" where all major functions are integrated onto a single board (Compl. ¶¶87-90, 105, 107). Plaintiff alleges that the patented gamma control technology is present in a dedicated chip or as part of a multi-function integrated circuit in these designs and that the gamma values are calibrated and stored during manufacturing (Compl. ¶¶89, 103). The complaint alleges that SAMEX's Tijuana facility manufactures approximately 19 million LCD televisions annually for the U.S. market (Compl. ¶21).

IV. Analysis of Infringement Allegations

The complaint references, but does not contain, detailed infringement charts. The following tables summarize the infringement theories for the lead asserted claims based on the narrative allegations in the complaint.

'305 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
An integrated circuit...comprising: a plurality of non-volatile storage cells The Accused Products allegedly contain an integrated circuit with non-volatile storage cells for storing gamma reference voltages. ¶123 col. 5:44-46
circuits for programming coupled to a multiplexer for addressing and programming said storage cells The accused circuit allegedly includes programming circuits and a multiplexer to address and program the storage cells. ¶123 col. 3:50-58
drivers connected to said storage cells and to the plurality of outputs The accused circuit allegedly has drivers that connect the storage cells to the circuit's outputs to provide the gamma voltages. ¶123 col. 4:11-14
said non-volatile storage cells are organized into two or more banks of cells wherein each bank contains a predetermined gamma reference voltage signal display condition The non-volatile storage cells are allegedly organized into banks, each storing a different set of gamma values for a specific display condition. ¶123 col. 5:50-52
and means to switch between the banks based on one or more external signals is provided on said integrated circuit The accused circuit allegedly includes a mechanism to switch between the different banks of gamma values using external signals. ¶123 col. 5:52-54

'788 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a. providing said display with gamma reference control capability which is electrically reprogrammable and non-volatile The manufacturing process allegedly provides a display with the accused integrated circuit, which has reprogrammable, non-volatile gamma control. ¶153 col. 2:16-29
b. testing said display with at least one sensor with optical input, wherein said sensor is separate from said display The calibration process allegedly uses a separate optical sensor to test the display's output during manufacturing. ¶153 col. 7:21-24
c. varying gamma reference voltage levels on columns of said display by a control circuit, where said control circuit is separate... The manufacturing process allegedly uses a separate control circuit to vary the gamma voltages applied to the display columns. ¶153 col. 3:20-25
d. optimizing said gamma reference voltage levels using means for executing a predetermined algorithm... The process allegedly uses a predetermined algorithm, executed by a separate means (e.g., a connected computer), to optimize the voltages based on sensor data. ¶153 col. 7:16-20
e. storing said gamma reference voltage levels in said gamma reference control capability The final, optimized gamma voltage values are allegedly stored in the non-volatile memory of the gamma control circuit. ¶153 col. 3:26-29

Identified Points of Contention

  • Structural Mapping ('305 Patent): A potential issue is whether the structures within Defendants' modern, highly-integrated circuits map to the claimed elements. For example, the analysis may question whether the accused multi-function chips in "two-board" or "3-in-1" designs (Compl. ¶¶89-90) contain the claimed arrangement of a "multiplexer," "programming circuits," and "drivers," or if they use a fundamentally different architecture.
  • Process Proof ('788 Patent): The complaint acknowledges that the accused calibration process occurs in private manufacturing facilities and invokes 35 U.S.C. § 295 to shift the burden of proof to Defendants (Compl. ¶¶155-156). A central dispute may be whether Plaintiff can first establish the "substantial likelihood" that the patented process was used, which is a prerequisite for the burden to shift.

V. Key Claim Terms for Construction

The Term: "means to switch between the banks" ('305 Patent, Claim 1)

  • Context and Importance: This term is in means-plus-function format under 35 U.S.C. § 112, para. 6. Its scope is not the literal meaning of the words but is limited to the specific structure disclosed in the patent's specification for performing the "switching" function, plus any structural equivalents. The infringement determination will depend on whether the accused products use a structure that is the same or equivalent to what is disclosed in the patent.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The stated function is "to switch between the banks" ('305 Patent, col. 8:60-61). A party could argue that any mechanism accomplishing this selection, whether hardware or software, is functionally driven and should be considered.
    • Evidence for a Narrower Interpretation: The specification describes the corresponding structure as "the three address inputs B0, B1, B2" ('305 Patent, col. 5:52-54; Fig. 6). A party could argue the claim is limited to a structure of physical address pins for bank selection and their direct structural equivalents, not different methods like serial commands or software-based registers.

The Term: "optimizing said gamma reference voltage levels using means for executing a predetermined algorithm" ('788 Patent, Claim 1)

  • Context and Importance: This is another means-plus-function term. The dispute will likely focus on identifying the corresponding structure in the specification and comparing it to the equipment and software used in Defendants' manufacturing process.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification suggests the structure can be a "PC based programming interface" running "Display optimization algorithms" that processes feedback from "optical sensors" ('788 Patent, col. 7:12-24). A party may argue this covers any general-purpose computer running software in a feedback loop to perform calibration.
    • Evidence for a Narrower Interpretation: A party could argue the structure is limited to an external PC connected to the display for testing, as described ('788 Patent, col. 7:12-20). If Defendants' process uses, for example, a built-in self-test and calibration routine executed entirely by the display's internal processors without an external computer, it could be argued to be a non-equivalent structure.

VI. Other Allegations

Indirect Infringement

Plaintiff accuses Samsung Electronics and Samsung Display of induced and contributory infringement (Compl. ¶¶135-141). The allegations are based on Defendants' asserted pre-suit knowledge of the patents, their role in designing the accused products and directing SAMEX to manufacture them, and their act of supplying key components (e.g., T-Con boards, integrated circuits, and display panels) that are alleged to be especially made for infringement and not staple articles of commerce (Compl. ¶¶49, 138-139).

Willful Infringement

The complaint alleges willful infringement by all Defendants, based primarily on extensive pre-suit knowledge allegedly obtained by Samsung Electronics and Samsung Display (Compl. ¶¶167-172). Key allegations supporting willfulness include a history of technical meetings with the inventor's company (Alta) between 2003 and 2012, presentations disclosing the patented technology, and the provision of product datasheets marked with the asserted patent numbers to a Samsung manager in 2012 (Compl. ¶¶70-73).

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

  • A central threshold question will be one of corporate knowledge and intent: can the technical interactions between Plaintiff's predecessor and Samsung's Display Division from over a decade ago establish pre-suit knowledge and a deliberate disregard of patent rights sufficient to support a finding of willfulness across the entire, multi-national Samsung enterprise as it exists today?
  • A key evidentiary question will be one of process proof: for the '788 method patent, can Plaintiff produce sufficient evidence to meet the "substantial likelihood" threshold of 35 U.S.C. § 295, thereby shifting the burden to Defendants to prove their confidential manufacturing and calibration processes do not infringe?
  • A core technical issue will be one of structural equivalence: can the "means to switch between the banks" language in the '305 patent, which the specification links to a set of hardware address pins, be construed to read on the functionality within the highly integrated, multi-function system-on-a-chip processors used in modern televisions?