Clean Alert Innovations LLC v. Omron Corp

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Clean Alert Innovations, LLC (Delaware)
  • Defendant: OMRON Corporation (Japan)
  • Plaintiff’s Counsel: Rabicoff Law LLC
• Case Identification: 2:25-cv-00447, E.D. Tex., 04/28/2025
• Venue Allegations: Plaintiff alleges venue is proper in the Eastern District of Texas 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 Defendant infringes a patent related to technology for detecting when an air filter is clogged.
• Technical Context: The technology concerns sensors for monitoring airflow in systems like HVAC units or internal combustion engines to determine filter effectiveness and signal the need for replacement.
• Key Procedural History: The original patent owner and developer of the technology was CleanAlert, LLC, which allegedly commercialized products (Filterscan, AirFilterSentry) practicing the patent and marked them with the patent number. On October 26, 2023, CleanAlert, LLC, ceased product sales and assigned its patent portfolio to the current Plaintiff, Clean Alert Innovations, LLC.

Case Timeline

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

U.S. Patent No. 7,178,410 - “Clogging detector for air filter,” issued Feb. 20, 2007

The Invention Explained

• Problem Addressed: The patent addresses the inefficiency and unreliability of common methods for determining when to change an air filter, such as visual inspection or scheduled replacement, which fail to account for actual operating conditions and contaminant levels ('410 Patent, col. 1:43-59). Methods based on measuring pressure differential across the filter were described as potentially expensive or impractical for some systems ('410 Patent, col. 2:1-4; col. 2:62-67).
• The Patented Solution: The invention proposes a detector based on a "thermo-anemometer," which directly measures the rate of airflow ('410 Patent, col. 4:51-57). The system uses a heated temperature sensor and an electronic servo circuit to maintain the sensor's temperature at a fixed level above the ambient air temperature. As airflow increases, more heat is carried away from the sensor, and the circuit must supply more electrical power to maintain the temperature differential. This required power serves as a direct measure of the airflow rate ('410 Patent, col. 5:48-61). When the measured airflow drops below a preset threshold—indicating the filter is clogged—an alarm is triggered ('410 Patent, col. 4:60-63).
• Technical Importance: This approach offers a method for filter monitoring based on the direct consequence of clogging—reduced airflow—rather than indirect or arbitrary metrics like time or visual appearance ('410 Patent, col. 1:55-59).

Key Claims at a Glance

• The complaint asserts infringement of unspecified "Exemplary '410 Patent Claims" but does not identify any specific independent claims in the body of the complaint (Compl. ¶16). Independent Claim 1 is the broadest claim of the patent.
• Essential Elements of Independent Claim 1:
  • A gas filter clogging detector for installation at a gas conduit attached to a gas blower having power to move gas and a gas filter, comprises in combination:
  • a base;
  • a power supply;
  • a flow rate sensor attached to said base and intended for monitoring a flow rate of gas by generating the output signal, being positioned at the gas conduit;
  • a threshold value generator;
  • a threshold comparator for comparing the said output signal with a selected threshold value and producing the alarm;
• The complaint does not explicitly reserve the right to assert dependent claims but refers generally to "one or more claims of the '410 Patent" (Compl. ¶16).

III. The Accused Instrumentality

Product Identification

• The complaint alleges infringement by unspecified "Exemplary Defendant Products" (Compl. ¶16). These products are purportedly identified in charts within Exhibit 2, which is referenced by but not attached to the complaint filing (Compl. ¶16, ¶21).

Functionality and Market Context

• The complaint does not provide sufficient detail for analysis of the accused products' functionality or market context beyond the general allegation that they "practice the technology claimed by the '410 Patent" (Compl. ¶21).

IV. Analysis of Infringement Allegations

The complaint alleges that infringement is detailed in claim charts provided as Exhibit 2 (Compl. ¶21, ¶22). As this exhibit was not provided, a detailed element-by-element analysis is not possible.

The narrative infringement theory states that the "Exemplary Defendant Products" practice the technology of the '410 Patent and, accordingly, "satisfy all elements of the Exemplary '410 Patent Claims" (Compl. ¶21). The complaint alleges direct infringement through Defendant's making, using, selling, and importing of the products, as well as internal testing (Compl. ¶16, ¶17). No probative visual evidence provided in complaint.

• Identified Points of Contention: Based on the patent language and the general nature of the allegations, the dispute may center on the following questions:
  • Scope Questions: How broadly will the claims be construed? For example, does the "flow rate sensor" of Claim 1 read on any technology that measures airflow, or is its scope limited by the specification's detailed focus on a specific type of thermo-anemometer?
  • Technical Questions: Assuming Plaintiff identifies accused products, a key factual question will be whether the operational principles of the defendant's technology match the claimed functions. For instance, do the accused products utilize a "threshold value generator" and "threshold comparator" that operate in the manner required by the claims?

V. Key Claim Terms for Construction

• The Term: "flow rate sensor" (from Claim 1)

  • Context and Importance: This term is the core of the invention. Its definition will determine whether the claim is limited to the specific thermo-anemometer embodiment detailed in the patent or covers a wider range of airflow measurement technologies. Practitioners may focus on this term because its scope is arguably narrowed by the specification's repeated emphasis on a "novel" thermo-anemometer design.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The term itself is generic. Claim 1 does not, on its face, restrict the "flow rate sensor" to any particular type.
    • Evidence for a Narrower Interpretation: The abstract states the invention is "built in form of a novel thermo-anemometer" ('410 Patent, Abstract). The "Summary of Invention" section describes the sensor as a "thermo-anemometer which contains at least one temperature sensor, a heating element, and a thermal insulator" ('410 Patent, col. 4:52-55). Dependent Claim 7 explicitly recites a "thermo-anemometer probe," suggesting the broader term in Claim 1 may be interpreted in light of these more specific descriptions.

• The Term: "threshold value generator" (from Claim 1)

  • Context and Importance: This is a functional limitation, and its construction is critical for determining infringement. The dispute will likely involve what actions or components are required to "generate" the threshold value.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The plain language suggests any hardware or software component that produces a threshold value for comparison.
    • Evidence for a Narrower Interpretation: The specification describes a specific "self-calibration" process for establishing the threshold, which involves measuring flow with a new filter and with the blower off to define the operational range, and then computing the threshold based on these points ('410 Patent, col. 6:15-34). A party could argue that a "generator" must be capable of performing a similar calibration or computation, rather than simply using a pre-programmed, fixed value.

VI. Other Allegations

• Indirect Infringement: The complaint alleges induced infringement, stating that Defendant distributes "product literature and website materials" that instruct end users to operate the accused products in a manner that infringes the '410 Patent (Compl. ¶19).
• Willful Infringement: Willfulness is alleged based on knowledge obtained "at least since being served by this Complaint" (Compl. ¶20). The complaint asserts that service of the complaint and its attached (but missing) claim charts constitutes "actual knowledge of infringement" (Compl. ¶18), framing the basis for willfulness as post-filing conduct.

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

1. Evidentiary Specification: The most immediate issue is the complaint's lack of specificity. The case hinges on information—the identity of the "Exemplary Defendant Products" and the corresponding "Exemplary '410 Patent Claims"—that is referenced in but absent from the public filing. The initial phase of litigation will likely focus on compelling the plaintiff to provide this missing detail.

2. Definitional Scope: A core legal issue will be claim construction, particularly for the term "flow rate sensor". The court will need to determine whether the claim scope is limited to the specific "novel thermo-anemometer" heavily featured in the patent's specification or if the plain language allows it to cover a broader class of airflow measurement devices.

3. Operational Equivalence: Once products and claims are identified, a central factual question will be one of operational methodology. Does the accused technology, particularly its method for setting an alert level, meet the functional requirements of a "threshold value generator" and "threshold comparator" as claimed, or is there a fundamental mismatch in how the accused system is calibrated and operated?