DCT

1:25-cv-00769

Densys Ltd v. Medit Corp

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Key Events
Amended Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:25-cv-00769, D. Del., 01/12/2026
  • Venue Allegations: Plaintiff alleges venue is proper in any U.S. judicial district because Defendant is a foreign corporation not resident in the U.S.
  • Core Dispute: Plaintiff alleges that Defendant’s intraoral 3D scanners and associated software infringe patents related to methods for registering multiple 3D scans and for modeling 3D surfaces using structured light.
  • Technical Context: The technology at issue pertains to digital dentistry, where intraoral scanners create 3D digital models of a patient's mouth, replacing traditional, physical impression materials.
  • Key Procedural History: The complaint notes that the ’707 Patent was previously litigated in Densys v. 3Shape, where a jury found that competitor 3Shape willfully infringed. This prior verdict is cited to support allegations of Defendant's knowledge and willfulness in the current case. The ’257 Patent underwent ex parte reexamination, resulting in the confirmation of claim 1, the amendment of claim 2, and the addition of new claims 3-5.

Case Timeline

Date Event
2000-06-28 Earliest Priority Date for U.S. Patent No. 6,402,707
2002-06-11 U.S. Patent No. 6,402,707 Issued
2006-01-11 Earliest Priority Date for U.S. Patent No. 8,665,257
2014-03-04 U.S. Patent No. 8,665,257 Issued
2019-01-01 Alleged start of sales for infringing Medit scanner models
2019-08-20 Reexamination Certificate for U.S. Patent No. 8,665,257 Issued
2026-01-12 Complaint Filed

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

U.S. Patent No. 6,402,707 - *"Method and system for real time intra-orally acquiring and registering three-dimensional measurements and images of intra-oral objects and features"*

The Invention Explained

  • Problem Addressed: The patent describes the technical challenge of combining multiple, discrete 3D scans of a patient's mouth into a single, accurate panoramic model. Errors can propagate when "piecing or merging" data from a scanner that is moved to different locations, decreasing the final model's precision (Compl. ¶17; ’707 Patent, col. 4:1-5).
  • The Patented Solution: The invention proposes establishing a single "intra-oral fixed global registration position" inside the patient's mouth. A mobile scanning device measures its own position and orientation relative to this fixed reference point. This allows each individual scan, captured from a different location, to be registered within a single, global coordinate system, creating a cohesive and accurate composite 3D model without requiring the reference point to be visible in every scan (’707 Patent, Abstract; col. 9:8-14).
  • Technical Importance: This approach provided a method for creating accurate, full-mouth digital impressions by ensuring all scanned data relates back to a common, stable frame of reference, overcoming limitations of prior art systems that struggled with stitching together images from a freely-held scanner (’707 Patent, col. 6:50-68).

Key Claims at a Glance

  • The complaint asserts independent claims 1 and 37 (Compl. ¶33).
  • The essential elements of independent method claim 1 include:
    • (a) establishing an intra-oral fixed global registration position inside the oral cavity of a dental patient, definable in a global coordinate space;
    • (b) providing a measuring and imaging device;
    • (c) selecting a field of view of the device at a global position;
    • (d) acquiring a 3D measurement and image of objects in the field of view, and recording the device's global position relative to the fixed registration position;
    • (e) repeating steps (c) and (d) for a plurality of positions to form a plurality of globally recorded measurements and images; and
    • (f) registering local coordinate space pixel positions from each measurement with corresponding global coordinate space pixel positions.
  • The complaint does not explicitly reserve the right to assert dependent claims.

U.S. Patent No. 8,665,257 - *"Three-dimensional modeling of the oral cavity"*

The Invention Explained

  • Problem Addressed: The patent addresses the difficulty of 3D modeling surfaces that lack distinct features, such as teeth. Without sufficient surface detail, it is difficult to unambiguously match points between different images to perform triangulation, a common method for calculating 3D geometry (’257 Patent, col. 2:51-54).
  • The Patented Solution: The invention solves this by projecting a pre-defined, reproducible pattern of "structured illumination"—specifically, a two-dimensional array of random patterns—onto the intra-oral scene. A single camera captures an image of how this known pattern is distorted by the 3D surface of the teeth. By comparing the captured, distorted pattern to a stored reference image of the pattern projected on a known surface (e.g., a plane), the system can calculate the 3D coordinates of each point in the pattern via triangulation (’257 Patent, Abstract; col. 6:46-61).
  • Technical Importance: This technique allows for 3D data acquisition from a single image capture, reducing errors caused by patient or operator movement, and enables accurate modeling of feature-poor surfaces common in dentistry (’257 Patent, col. 3:6-14).

Key Claims at a Glance

  • The complaint asserts independent claim 1 (Compl. ¶47).
  • The essential elements of independent system claim 1 include:
    • a pattern generator for generating a 2D array of random 2D or 1D patterns;
    • a projectable medium with a memory for storing the array;
    • a projector for projecting the array onto the intra-oral scene at a first angle;
    • an acquiring unit (e.g., a camera) for acquiring images of the projected array from a second angle;
    • calculators and software for pattern-matching, calculating parallax, and calculating 3D positions based on the parallax; and
    • modeling software for constructing a 3D model.
  • The complaint does not explicitly reserve the right to assert dependent claims.

III. The Accused Instrumentality

Product Identification

  • The accused products include Medit-branded intraoral scanners (e.g., i900, i700, i600, i500 series) and related software (e.g., Medit Scan and Medit Link) sold from 2019 to the present (Compl. ¶21).

Functionality and Market Context

  • The complaint describes the accused products as a complete intraoral scanning system that allows dentists to digitally scan a patient's mouth and generate virtual 3D models for dental applications (Compl. ¶18, ¶21). These systems are alleged to be part of a foundational shift in the dental industry away from physical impression materials toward fully digital workflows (Compl. ¶19).

IV. Analysis of Infringement Allegations

The complaint references preliminary claim charts in Exhibits 3 and 4, which were not provided with the filed complaint. The infringement analysis is therefore based on the narrative allegations.

'707 Patent Infringement Allegations

  • The complaint alleges that the Accused Products perform a method of creating a 3D model by acquiring and registering multiple images, thereby meeting every limitation of at least claims 1 and 37 (Compl. ¶33). The core of this allegation is that the Medit system necessarily establishes and uses a registration system equivalent to the claimed "intra-oral fixed global registration position" to combine multiple scans into a single, coherent 3D model (Compl. ¶33-¶34).

'257 Patent Infringement Allegations

  • The complaint alleges that the Accused Products are a system that meets every limitation of at least claim 1 (Compl. ¶47). The infringement theory appears to be that the Medit scanners operate by projecting a structured light pattern onto the teeth and using a camera to capture the distorted pattern, which is then processed by software to create a 3D model, thereby embodying the claimed system (Compl. ¶47-¶48). The complaint includes a screenshot from a 2014 user manual for Plaintiff's Mia3D product, which lists the ’257 Patent as covering the product, to support allegations of Defendant's knowledge (Compl. ¶23). This screenshot shows a notice listing U.S. Patent Nos. 8,665,257 and 6,402,707, among others, as covering the product (Compl. p. 6).

Identified Points of Contention

  • Scope Questions (’707 Patent): A central question may be whether the term "establishing an intra-oral fixed global registration position" requires a distinct, physically or virtually anchored reference point that persists throughout the scanning session. The defense may argue that the accused system uses a different registration technique, such as feature-matching and aligning overlapping portions of consecutive scans (e.g., an Iterative Closest Point algorithm), which does not rely on a "fixed global" position as described in the patent.
  • Technical Questions (’257 Patent): The analysis may focus on whether the pattern projected by the Medit scanners qualifies as an "array of... random... patterns" under the patent's claims. The construction of "random" will be critical, particularly in light of the reexamination history, which added dependent claims specifying patterns that are "randomly shaped" and "randomly distributed." Evidence regarding the specific nature, reproducibility, and characteristics of the projected light patterns in the accused scanners will be central to this inquiry.

V. Key Claim Terms for Construction

  • The Term: "intra-oral fixed global registration position" (’707 Patent, Claim 1)

    • Context and Importance: This term is the central inventive concept of the ’707 Patent. Its construction will determine whether the patent reads on modern scanner registration techniques that may not use a discrete, separately established reference object. Practitioners may focus on whether this term can encompass software-based registration methods that create a frame of reference from initial scan data, or if it is limited to a pre-defined point independent of the scanned surfaces.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The claim language requires the position to be "definable in terms of global coordinate space" but does not explicitly require a physical object (’707 Patent, col. 24:38-40). This may support an argument that a virtual reference point established by software falls within the claim scope.
      • Evidence for a Narrower Interpretation: The specification repeatedly describes the implementation using an "intra-oral fixed global registration device" that is "positioned and temporarily fixed onto any intra-oral object and/or feature" such as a tooth (’707 Patent, col. 14:28-34). This language, tied to a physical embodiment, could support a narrower construction limited to systems that use such a distinct reference device.

  • The Term: "random two-dimensional or one-dimensional patterns" (’257 Patent, Claim 1)

    • Context and Importance: The use of "random" patterns is key to the patent's anti-aliasing solution, which avoids false matching of structured light points. The definition of "random" will be pivotal to the infringement analysis. The dispute may turn on whether the accused system's pattern is sufficiently non-repeating and unpredictable to meet the claim's requirement.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The specification describes the patterns as "probabilistically unique over the entire area," suggesting that a pattern which is practically, but not absolutely, unique could be considered "random" (’257 Patent, col. 8:25-28). This could cover pseudo-random or complex, repeating patterns.
      • Evidence for a Narrower Interpretation: The patent distinguishes its reproducible, stored random patterns from the non-reproducible patterns created by prior art laser speckle, but emphasizes their non-repeating nature to solve aliasing (’257 Patent, col. 4:40-52, col. 5:62-65). This could support a narrower construction that excludes patterns with any significant degree of regularity or repetition within a single projection.

VI. Other Allegations

Indirect Infringement

  • The complaint alleges inducement of infringement, stating that Medit provides promotional materials, training, instructions, and user guides that encourage and instruct customers to use the Accused Products in a manner that directly infringes the patents-in-suit (Compl. ¶37, ¶52).

Willful Infringement

  • The complaint alleges that Medit's infringement was and continues to be willful. The basis for this allegation includes alleged pre-suit knowledge stemming from: (1) Medit and Densys both presenting scanner products at the same industry trade shows since at least 2015 (Compl. ¶23); (2) the patents-in-suit being publicly listed on Densys's product user manuals since at least 2014 (Compl. ¶23); (3) Medit's own patents citing Densys's intellectual property (Compl. ¶24); and (4) Medit's alleged awareness of the jury verdict finding willful infringement of the ’707 Patent by competitor 3Shape (Compl. ¶27).

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

  • A core issue will be one of technical mechanism: Does the Medit system's software architecture for combining multiple scans rely on "establishing an intra-oral fixed global registration position" as required by the ’707 Patent, or does it operate on a fundamentally different principle of continuous, overlapping surface registration that falls outside the claim scope?
  • A key question of definitional scope will concern the ’257 Patent: Can the term "random... patterns" be construed to read on the specific structured light pattern generated by the accused Medit scanners, especially in view of the patent's prosecution and reexamination history?
  • A central dispute regarding damages will be willfulness and knowledge: Given the prior litigation involving the ’707 Patent against a direct competitor and other alleged forms of notice, what evidence will be required to determine whether Medit acted with the knowledge and intent necessary to support a finding of willful infringement?