DCT
3:25-cv-01625
Duos Technologies Inc v. Norfolk Southern Corp
Key Events
Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Duos Technologies, Inc. (Florida)
- Defendant: Norfolk Southern Corp (Virginia/Georgia)
- Plaintiff’s Counsel: Lawson Huck Gonzalez, PLLC
- Case Identification: 3:25-cv-01625, M.D. Fla., 12/30/2025
- Venue Allegations: Plaintiff alleges venue is proper in the Middle District of Florida because Defendant maintains a regular and established place of business in the district, has committed acts of infringement in the district, and operates the accused inspection portals on trains that travel through Florida.
- Core Dispute: Plaintiff alleges that Defendant’s "Digital Train Inspection Portals" infringe four patents related to automated, real-time railcar imaging and defect detection technology.
- Technical Context: The technology at issue involves automated track-side and portal-based systems that use high-speed cameras, advanced lighting, and artificial intelligence to inspect moving trains, a domain critical for improving railway safety and operational efficiency.
- Key Procedural History: The complaint alleges that Plaintiff provided Defendant with multiple written notices of infringement beginning on June 10, 2024, and that Defendant continued to deploy the accused systems after receiving these notices, forming the basis for a willfulness allegation.
Case Timeline
| Date | Event |
|---|---|
| 2015-12-16 | ’858 Patent Priority Date |
| 2019-12-31 | U.S. Patent No. 10,523,858 Issued |
| 2021-05-21 | ’846 Patent Priority Date |
| 2022-10-19 | ’035 Patent Priority Date |
| 2023-03-22 | ’098 Patent Priority Date |
| 2023-10-26 | First Accused Portal Deployed in Leetonia, Ohio |
| 2024-02-06 | U.S. Patent No. 11,891,098 Issued |
| 2024-04-30 | U.S. Patent No. 11,974,035 Issued |
| 2024-06-10 | Plaintiff sends first written notice of infringement |
| 2024-07-29 | Plaintiff sends second written notice of infringement |
| 2024-08-14 | Defendant responds to notice, denying infringement |
| 2025-01-07 | U.S. Patent No. 12,188,846 Issued |
| 2025-08-29 | Plaintiff sends third and final written notice of infringement |
| 2025-12-30 | Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 10,523,858 - "Apparatus and Method to Capture Continuous High Resolution Images of a Moving Train Undercarriage"
The Invention Explained
- Problem Addressed: The patent addresses the need to inspect the undercarriage of a moving train to avoid the significant time and resource costs associated with stopping a train for manual inspection (Compl. ¶16; ’858 Patent, col. 1:59-65).
- The Patented Solution: The invention is a system, housed in a container mounted between railroad ties, that uses a "linear speed detection device" to precisely measure a train's speed. This speed data is then used by software to control the frame rate of a camera and associated lighting, allowing for the capture of clear, continuous high-resolution images of the train's undercarriage as it passes overhead. The system uses a mirror to deflect the image to the camera and software to reassemble the captured image fragments (’858 Patent, Abstract; col. 2:42-56).
- Technical Importance: This approach enables automated, in-motion inspection of critical undercarriage components, aiming to improve safety and operational efficiency compared to traditional stationary inspection methods (Compl. ¶20).
Key Claims at a Glance
- The complaint asserts infringement of Claim 1 of the ’858 Patent (Compl. ¶47).
- Essential elements of independent claim 1 include:
- An apparatus comprised of a container housing components including a camera, a mirror, illumination means, anti-glare glass, and a controller.
- A linear speed detection device that measures the train's speed using a plurality of sensors.
- A controller for the speed detection device.
- Software that controls the system's activation, camera speed, and lighting, and permits image reassembly.
- An alarm to alert personnel of anomalies.
- The complaint does not explicitly reserve the right to assert dependent claims for this patent.
U.S. Patent No. 11,974,035 - "Device to Capture High Resolution Images of a Train as It Passes Through a Portal"
The Invention Explained
- Problem Addressed: The patent identifies the challenge of capturing high-quality images of a moving train within an inspection portal, citing interference from airborne contaminants (dust, debris) and ambient light, both of which can distort images and smudge camera lenses (’035 Patent, col. 1:30-43).
- The Patented Solution: The invention is a portal structure equipped with a plurality of line scan cameras and LED lighting mounted on its interior trusses to capture side and top views of a train. To solve the stated problem, the cameras are fitted with "a pair of blinders (referred to a duckbills in the industry)" that block contaminants and ambient light. The system further employs software with an artificial intelligence component to restitch the captured image slices and identify anomalies (’035 Patent, col. 1:44-57; col. 4:5-11).
- Technical Importance: This technology provides an environmentally hardened, portal-based system designed to ensure the capture of clear, comprehensive images of moving railcars for automated inspection (Compl. ¶17).
Key Claims at a Glance
- The complaint asserts infringement of "at least Claim 1" of the ’035 Patent (Compl. ¶53).
- Essential elements of independent claim 1 include:
- An inspection portal with a defined structure (walls and top).
- A plurality of line scan cameras mounted to the interior sides and top of the portal.
- A pair of line scan cameras on the top surface, one configured for the railcar top and one for the knuckle assembly.
- "duckbill plates" placed on each of the plurality of line scan cameras.
- A means of illumination that is "LED lighting."
- Software that includes a controller and incorporates "artificial intelligence."
- The complaint does not explicitly reserve the right to assert dependent claims for this patent.
U.S. Patent No. 11,891,098 - "Use of Artificial Intelligence to Detect Defects in Trains and Method to Use"
The Invention Explained
- Technology Synopsis: This patent addresses the automated analysis of train images. The patented solution employs artificial intelligence and supervised machine learning models to analyze captured images, comparing them against stored models of railcar types to identify anomalies. The system also discloses a "human in the loop" (HITL) process to validate the AI-detected defects and retrain the models (’098 Patent, Abstract; col. 3:1-25). (Compl. ¶18).
Key Claims at a Glance
- Asserted Claims: Claim 1 (Compl. ¶59).
- Accused Features: The complaint alleges that Norfolk Southern's portals use "AI-driven algorithms" and a "human in the loop" feature for verification, directly corresponding to the patent's claims (Compl. ¶¶ 32, 35, 60).
U.S. Patent No. 12,188,846 - "Capturing Images of the Underside of a Train"
The Invention Explained
- Technology Synopsis: This patent focuses on capturing images of specific undercarriage components like the "F-pin" coupler system, which may be obscured from a direct downward view. The solution involves a specialized arrangement of camera and LED modules housed in chassis mounted to a rail tie. The modules are positioned at specific angles (e.g., 40 degrees relative to horizontal) to provide clear views of the F-pin system from the side of the undercarriage (’846 Patent, Abstract; col. 2:25-47). (Compl. ¶19).
Key Claims at a Glance
- Asserted Claims: "at least Claim 1" (Compl. ¶65).
- Accused Features: The complaint alleges that Defendant's inspection systems "capture underside images in substantially the same way" as claimed in the patent (Compl. ¶65).
III. The Accused Instrumentality
Product Identification
- Defendant's "Digital Train Inspection Portals" or "DTI Portals" (Compl. ¶22).
Functionality and Market Context
- The DTI Portals are described as tunnel-like structures that employ "machine vision technology" to perform a "360-degree view" inspection of passing trains (Compl. ¶¶ 28.a, 36.a). The system allegedly uses 38 high-resolution cameras, including a mix of area and line scan models, and "powerful lights" to capture approximately 1,000 images per railcar (Compl. ¶¶ 28.b-c, 29.b). The complaint asserts that sensors determine the train's speed to "precisely control when the photographs are taken" (Compl. ¶28.d). The captured images are then analyzed by "75-plus AI algorithms" to identify defects, with results transmitted to a Network Operations Center for review by "subject-matter experts" (Compl. ¶¶ 29.c, 32.a). The complaint references a screenshot from a YouTube video posted by Norfolk Southern showing the DTI Portal capturing images (Compl. ¶27.b, Ex. I). Defendant has allegedly deployed these portals at multiple sites with plans to expand to "achieve about 90% coverage over the next several years," positioning them as a key safety technology (Compl. ¶¶ 23-24).
IV. Analysis of Infringement Allegations
U.S. Patent No. 10,523,858 Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| An apparatus... comprised of: a. a container... | The complaint alleges the use of cameras "at track level pointing up," which implies a protective housing or container. | ¶30.a | col. 2:48-56 |
| b. a linear speed detection device; wherein the linear speed detection device measures the speed of the train... | The accused portals use "Sensors at each portal [that] determine the speed of each train passing through." | ¶28.d | col. 2:57-65 |
| d. a camera; wherein the camera is capable of taking high resolution images... | The accused portals use "38 high-resolution cameras" to photograph components of each railcar. | ¶28.b | col. 4:26-33 |
| e. a mirror; wherein a mirror is provided to permit the gathering of the high resolution images... | The complaint makes a conclusory allegation that the portals "use cameras, mirrors, and lighting to generate the same type of undercarriage images." | ¶47 | col. 4:39-44 |
| f. lighting means... | The portals use "Powerful lights comparable to those used in sports stadiums" and "stadium lights." | ¶28.c | col. 3:51-54 |
| g. software; wherein the software controls the activation and deactivation of a system... | Software "calculates in real time when to tell each camera to take a picture" and synchronizes cameras and lights. | ¶28.e, ¶30.d | col. 3:62-65 |
U.S. Patent No. 11,974,035 Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a. an inspection portal wherein the inspection portal has a defined structure... | The accused system is a "Digital Train Inspection Portal" that "operates in a tunnel structure." | ¶22, ¶36.a | col. 1:16-19 |
| b. a plurality of line scan cameras; wherein some... are mounted to the side of the interior... and some... are mounted to the top... | The portals use a "mix of area and line scan cameras" to produce images of the "top, bottom, and sides of train cars." | ¶28.a, ¶28.b | col. 4:1-12 |
| d. duckbill plates; wherein a pair of duckbill plates are placed on each of the plurality of line scan cameras... | The complaint does not provide specific factual allegations regarding the presence of duckbill plates on the accused portals. | ¶54 | col. 1:47-52 |
| e. a means of illumination; wherein the means of illumination is LED lighting... | The accused portals use "stadium lights." | ¶29.a, ¶30.b | col. 1:50-57 |
| f. software; wherein... artificial intelligence is incorporated into the software. | The accused system uses "75-plus AI algorithms" and an in-house "Data Science/AI team." | ¶29.c, ¶35.c | col. 4:8-11 |
- Identified Points of Contention:
- Structural Questions: The analysis may turn on factual questions about the accused system's hardware. For the ’858 Patent, a central question is whether the accused system uses a "mirror" as claimed, or if its "track level" cameras capture images directly. For the ’035 Patent, key questions will be whether the accused system's "stadium lights" meet the specific claim requirement for "LED lighting" and whether the system incorporates "duckbill plates" or a structure the court would deem equivalent.
- Evidentiary Questions: The complaint relies heavily on public statements, press releases, and news articles to support its infringement allegations. The court will need to determine if these public-facing descriptions provide sufficient technical detail to map onto each specific limitation of the asserted claims, or if they represent high-level marketing statements that omit critical engineering details.
V. Key Claim Terms for Construction
- The Term: "mirror" (from ’858 Patent, Claim 1.e)
- Context and Importance: This term is critical because the patent's embodiment explicitly uses a mirror to deflect the undercarriage image to a protected camera (’858 Patent, col. 4:39-44). The complaint's allegation of a mirror is conclusory (Compl. ¶47), while its factual evidence points to "track level pointing up" cameras (Compl. ¶30.a), suggesting a potential design-around. The viability of the infringement claim may depend on whether this term is required or if an equivalent is present.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The term itself is simple and is not given a special definition in the patent, which may support giving it its plain and ordinary meaning without limitation to a specific type or placement of mirror.
- Evidence for a Narrower Interpretation: The specification and Figure 1 consistently depict the mirror as a distinct component that deflects the image from a vertical path to a horizontal path toward the camera. A defendant may argue that the claim, read in light of the specification, requires this specific reflective, multi-component optical path, and does not cover a system with a direct-view upward-facing camera.
- The Term: "duckbill plates" (from ’035 Patent, Claim 1.d)
- Context and Importance: This is a specific structural element recited in the claim, and the complaint provides no direct evidence that the accused DTI Portals use such a feature. Practitioners may focus on this term because infringement will likely require either direct evidence of the structure or a finding of equivalence. The patent describes these plates as protecting the camera lens from airborne contaminants and ambient light (’035 Patent, col. 1:47-52).
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent equates the term with "a set of flaps" and "a pair of blinders," suggesting the term could be construed to cover various shield-like structures attached to the camera, not just a single, specific design (’035 Patent, col. 1:47-49; col. 3:7-9).
- Evidence for a Narrower Interpretation: The patent also notes that "duckbills" is a term used "in the industry," which could suggest it has a particular meaning and structure understood by a person of ordinary skill in the art (’035 Patent, col. 1:48). A defendant might argue this limits the term's scope to that specific, known industrial component.
VI. Other Allegations
- Indirect Infringement: The complaint focuses on direct infringement by Defendant for its own use and operation of the DTI Portals and does not plead separate counts for induced or contributory infringement.
- Willful Infringement: The complaint makes a detailed claim for willful infringement. It alleges that Plaintiff sent three separate written notices of infringement to Defendant prior to filing suit, starting on June 10, 2024. The complaint further alleges that after receiving these notices, Defendant "continued and expanded the deployment of infringing systems," which Plaintiff characterizes as "egregious behavior" (Compl. ¶¶ 37-39).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of structural correspondence: Does the factual record show that Defendant's DTI Portals incorporate the specific hardware recited in the claims, such as the "mirror" of the ’858 patent and the "duckbill plates" and "LED lighting" of the ’035 patent, or will Plaintiff need to rely on the doctrine of equivalents to prove infringement?
- A key evidentiary question will be one of technical specificity: Will the public-facing technical articles and press releases cited in the complaint be sufficient to establish infringement of each claim limitation, or will they be found to be high-level marketing descriptions that lack the detail required to prove a technical match?
- A central issue for damages will be willfulness: Given the complaint's specific allegations of repeated pre-suit notice, did Defendant's continued and expanded use of the accused portals constitute the type of egregious conduct that would justify an award of enhanced damages under 35 U.S.C. § 284?