ZT IP LLC v. MathWorks Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: ZT IP, LLC (Texas)
  • Defendant: The MathWorks, Inc. (Delaware)
  • Plaintiff’s Counsel: Ramey LLP
• Case Identification: 6:22-cv-00438, E.D. Tex., 04/29/2022
• Venue Allegations: Venue is alleged to be proper as Defendant has a regular and established place of business in the district, has committed alleged acts of infringement in the district, and conducts substantial business there.
• Core Dispute: Plaintiff alleges that Defendant’s systems, products, and services for developing real-time operating systems infringe patents related to tools that automatically synthesize task management code.
• Technical Context: The technology concerns software development tools for real-time operating systems (RTOS), which are essential for embedded systems in fields like automotive, aerospace, and consumer electronics, where precise task scheduling and timing are critical.
• Key Procedural History: The complaint notes that Plaintiff owns the patents-in-suit by assignment. For U.S. Patent No. 6,934,947, Plaintiff reserves the right to amend its complaint to assert indirect and willful infringement. For U.S. Patent No. 7,882,488, the complaint alleges inducement and contributory infringement, with willfulness allegations based on knowledge as of the lawsuit's filing date. No prior litigation or administrative proceedings are mentioned.

Case Timeline

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

U.S. Patent No. 6,934,947 - "Visual Tool for Developing Real Time Task Management Code," issued August 23, 2005

The Invention Explained

• Problem Addressed: The patent describes a dilemma for developers of real-time systems. They could use a commercial Real-Time Operating System (RTOS) kernel, which is powerful but can be complex, bulky, and have unpredictable performance. Alternatively, they could manually create a "polling loop," which is simpler and more efficient but requires the programmer to handle all task management, scheduling, and deadlock prevention, a difficult and error-prone process (ʼ947 Patent, col. 1:11-61).
• The Patented Solution: The invention proposes a "virtual" RTOS, a software tool that automates the creation of an efficient polling loop. The tool provides a user interface and high-level commands for a programmer to define tasks, set priorities, and specify inter-task communications. The tool then automatically "synthesizes" the underlying source code for the polling loop, aiming to provide the simplicity and performance of a custom loop without the manual coding burden and risk of deadlocks (ʼ947 Patent, col. 2:1-10; col. 3:15-4:25).
• Technical Importance: The technology sought to offer a middle ground between monolithic RTOS kernels and manually coded schedulers, enabling more rapid and reliable development of optimized, application-specific real-time systems (ʼ947 Patent, col. 2:1-10).

Key Claims at a Glance

• The complaint asserts infringement of claims 1-9 (Compl. ¶9).
• Independent Claim 1 recites a method for developing a real-time task management system with the following key steps:
  • providing commands to be used in source codes of real-time tasks for synchronization;
  • assigning a priority to each task;
  • synthesizing source code for a polling loop that manages the tasks according to their assigned priority;
  • synthesizing source code for the provided commands; and
  • converting the synthesized source code for execution by a computer.

U.S. Patent No. 7,882,488 - "Software Tool For Synthesizing A Real-Time Operating System," issued February 1, 2011

The Invention Explained

• Problem Addressed: Like its parent, the ’488 Patent addresses the challenges of developing real-time embedded systems, highlighting the trade-offs between using a commercial RTOS kernel and a manually created polling loop, also known as a cyclic executive (’488 Patent, col. 1:13-55).
• The Patented Solution: The invention is a software tool that automatically generates, or "synthesizes," a real-time operating system. A developer uses the tool to define various types of tasks (e.g., initialization, periodic, event-driven) and their operational parameters like priority and timing. The tool then synthesizes the task management source code, including a scheduler and system calls, which is optimized for the specific application and hardware, thereby preventing hazards like deadlocks by design (’488 Patent, col. 2:1-20; col. 3:41-55).
• Technical Importance: This approach allows for the automated creation of custom, lightweight RTOSs, potentially offering superior performance, a smaller memory footprint, and faster development cycles compared to using general-purpose, off-the-shelf RTOS products (’488 Patent, col. 2:5-17).

Key Claims at a Glance

• The complaint asserts infringement of claims 1-24 (Compl. ¶14).
• Independent Claim 1 recites a method for developing a real-time operating system with the following key steps:
  • specifying a set of n tasks to be scheduled, including t initialization tasks;
  • using a data processor to synthesize source code from embedded commands to implement a task scheduler that controls the execution of the n tasks (and the t init-tasks once); and
  • synthesizing source code to control the execution of the t init-tasks by generating new code based on the embedded commands.

III. The Accused Instrumentality

Product Identification

• The complaint does not identify any specific accused products by name. It broadly refers to "systems, products, and services that facilitate developing real time task management system" and "real time operating system" (Compl. ¶¶ 9, 14).

Functionality and Market Context

• The functionality of the accused instrumentalities is described at a high level as tools that "facilitate developing" real-time systems (Compl. ¶¶ 9, 14). This suggests the accused products are software development environments, consistent with the defendant, The MathWorks, Inc., being a provider of technical computing software like MATLAB and Simulink. The complaint makes no allegations regarding the products' specific market position or commercial importance, other than that Defendant sells products and services in Texas (Compl. ¶3).

IV. Analysis of Infringement Allegations

The complaint references but does not include its claim chart exhibits (Exhibits A and B), instead stating they contain "exemplary" and "preliminary" allegations (Compl. ¶¶ 10, 15). In the absence of these exhibits, the infringement theory is summarized below in prose. No probative visual evidence provided in complaint.

• ’947 Patent Infringement Allegations
  The complaint alleges that Defendant's systems and products directly infringe claims 1-9 (Compl. ¶9). The narrative theory appears to be that Defendant's software development tools provide users with functions, commands, or graphical blocks that allow them to define a set of real-time tasks, assign priorities, and then automatically generate (or "synthesize") source code for a scheduler or executive (the "polling loop") that manages the execution of those tasks. This generated code is then compiled ("converted") for use on a target computer system, thereby practicing the steps of asserted method claim 1.

• ’488 Patent Infringement Allegations
  The complaint alleges that Defendant's products directly and indirectly infringe claims 1-24 (Compl. ¶¶ 14, 16-17). The infringement theory for the ’488 Patent is similar: Defendant's tools allegedly allow a user to specify a set of tasks (including initialization tasks) for a real-time system. The tools then use a data processor to "synthesize" source code that implements a "task scheduler" to control the execution of the specified tasks. This process is alleged to meet the limitations of the asserted claims.

• Identified Points of Contention:

  • Scope Questions: A central dispute may concern the scope of key claim terms. For the ’947 Patent, a question is whether the scheduling code generated by Defendant's modern tools constitutes a "polling loop" as that term is used in the patent, which contrasts it with more complex RTOS kernels. For the ’488 Patent, a similar question arises for the term "task scheduler."
  • Technical Questions: The complaint's allegations are not detailed. A primary technical question will be what evidence demonstrates that Defendant's unnamed products perform the specific "synthesizing" steps as required by the claims, as opposed to merely compiling user-written code or linking to standard libraries. The mechanism of code generation in the accused products will be a focal point.

V. Key Claim Terms for Construction

• The Term: "polling loop" (’947 Patent, Claim 1)

  • Context and Importance: This term is foundational to the ’947 Patent's infringement theory. The outcome may depend on whether the architecture of the code generated by Defendant's tools falls within the construction of "polling loop." Practitioners may focus on this term because Defendant could argue its tools generate a sophisticated, event-driven, or time-triggered scheduler, not the simpler, sequentially-checking "polling loop" described in the patent's preferred embodiments.
  • Intrinsic Evidence for a Broader Interpretation: The specification describes a polling loop as a general "task management scheme" that is an "alternative to managing the schedule from a commercially available kernel" (’947 Patent, col. 1:40-44).
  • Intrinsic Evidence for a Narrower Interpretation: The specification repeatedly contrasts the polling loop with an RTOS kernel by describing it as "simpler," requiring "less memory space," and being "easier to debug" (’947 Patent, col. 1:49-56). Furthermore, Figure 6(b) illustrates a specific structure where the loop code sequentially checks the "StateFlag" of each task before execution, which could support a narrower definition tied to this implementation (’947 Patent, col. 6:10-40).

• The Term: "synthesizing source code" (’947 Patent, Claim 1; ’488 Patent, Claim 1)

  • Context and Importance: This action is the core of the claimed methods. The dispute will likely involve whether the accused tools "synthesize" code in the claimed manner or perform a different function, such as compiling high-level models into code.
  • Intrinsic Evidence for a Broader Interpretation: The term could be interpreted to cover any automatic generation of source code from a higher-level user specification. The ’947 Patent abstract states the tool can "synthesize code of any specified programming language" (’947 Patent, Abstract).
  • Intrinsic Evidence for a Narrower Interpretation: The ’947 Patent describes a specific process of creating a "main polling loop" and "replacing all of the VIRTOS commands by actual code" (’947 Patent, col. 4:46-49). This suggests a template-and-replacement mechanism, which could be argued as narrower than the more complex transformations performed by modern code generators.

VI. Other Allegations

• Indirect Infringement: For the ’488 Patent, the complaint alleges induced infringement based on Defendant actively encouraging or instructing customers on how to use its products in an infringing manner (Compl. ¶16). It also pleads contributory infringement, alleging a lack of substantial non-infringing uses for the accused products (Compl. ¶17).
• Willful Infringement: For the ’488 Patent, willfulness is alleged based on Defendant’s knowledge of the patent and the alleged infringement "from at least the filing date of the lawsuit" (Compl. ¶¶ 16, 17). For the ’947 Patent, Plaintiff reserves the right to allege willfulness if pre-suit knowledge is revealed in discovery (Compl. ¶11, fn. 1).

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

1. A primary issue will be one of claim construction and scope: can the terms "polling loop" (’947 patent) and "task scheduler" (’488 patent), which are described in the patents as alternatives to complex commercial kernels, be construed broadly enough to read on the potentially more sophisticated real-time executives generated by Defendant’s modern software development tools?
2. A second central issue will be evidentiary and factual: given the complaint’s lack of specificity, can the Plaintiff produce evidence to show that a specific, identified MathWorks product actually performs the claimed methods of "synthesizing" source code in the particular manner required by the claims, or do the tools operate in a technically distinct way?
3. For the indirect infringement claims, a key question will be one of intent: what specific instructions, documentation, or marketing materials demonstrate that Defendant actively encouraged its customers to use its general-purpose tools to create infringing real-time systems, as required to prove inducement?