D4D Tech LLC v. Medit Corp

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: D4D Technologies, LLC (Delaware)
  • Defendant: Medit Corp. (Republic of Korea)
  • Plaintiff's Counsel: Scheef & Stone, LLP; Foley & Lardner LLP
• Case Identification: 6:21-cv-01176, W.D. Tex., 01/17/2024
• Venue Allegations: Venue is alleged to be proper because the defendant, Medit Corp., is a foreign corporation not resident in the United States, which under 28 U.S.C. § 1391(c)(3) permits suit in any judicial district.
• Core Dispute: Plaintiff alleges that Defendant's iSeries line of intraoral scanners and associated software infringes a patent related to methods of creating a 3D model by combining structured light scanning with photogrammetry.
• Technical Context: The technology at issue is intraoral 3D scanning, a key component of modern digital dentistry used to create digital models of a patient's teeth for manufacturing dental restorations like crowns and bridges.
• Key Procedural History: This First Amended Complaint follows a claim construction ruling from the Court regarding a related patent, U.S. Patent 7,342,668. Following that ruling, Plaintiff D4D Technologies has stipulated to non-infringement of the '668 patent for the purposes of this action, effectively focusing the dispute on the remaining patent-in-suit, U.S. Patent 7,978,892. The complaint alleges that Defendant Medit Corp. was on notice of the asserted patents since at least January 7, 2021.

Case Timeline

Date	Event
2003-09-17	U.S. Patent 7,342,668 Priority Date
2006-10-25	U.S. Patent 7,978,892 Priority Date
2008-03-11	U.S. Patent 7,342,668 Issue Date
2011-07-12	U.S. Patent 7,978,892 Issue Date
~2018	Medit i500 sales begin
2020-10	D4D sends notice letter to Medit
2020-12	D4D sends notice letters to Medit distributors
2021-01-07	Medit receives notice of D4D patents via distributor
~2021	Medit i700 sales begin
~2022	Medit i600 sales begin
2024-01-17	First Amended Complaint Filing Date

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

U.S. Patent No. 7,978,892 - "3D PHOTOGRAMMETRY USING PROJECTED PATTERNS"

• Patent Identification: U.S. Patent No. 7,978,892, "3D PHOTOGRAMMETRY USING PROJECTED PATTERNS", issued July 12, 2011.

The Invention Explained

• Problem Addressed: The patent's background section describes a challenge in applying traditional photogrammetry to dental imaging: surfaces like teeth often lack distinct features, making it difficult and computationally expensive to match corresponding pixels between two different images to calculate 3D coordinates '892 Patent, col. 1:21-29
• The Patented Solution: The invention proposes a hybrid method that combines structured light scanning with photogrammetry. First, a structured light pattern is projected onto the object to generate an initial, approximate 3D model '892 Patent, abstract This initial model is then used as a guide to simplify and accelerate the photogrammetry step, where corresponding pixels in full-illumination images are matched to compute a more accurate final 3D model '892 Patent, col. 1:36-43 '892 Patent, FIG. 5 This approach avoids the computationally intensive task of searching for matching pixels from scratch '892 Patent, col. 1:43-46
• Technical Importance: This two-step process was designed to make high-accuracy 3D scanning of feature-poor surfaces, like those in dentistry, more practical by significantly reducing computational load and improving the reliability of the pixel-matching process '892 Patent, col. 1:43-49

Key Claims at a Glance

• The complaint asserts independent claims 1 and 6, and the final infringement contentions include dependent claims 2-5 and 7-8 Compl. ¶32 Compl. Ex. 5, p. 155
• Independent Claim 1 requires the essential steps of:
  • Projecting a pattern onto an object from at least first and second positions.
  • Capturing both a pattern image (P) and a full illumination image (I) from each position.
  • Forming a 3D model from the pattern image for each position.
  • Using the 3D model to find corresponding "matched" pixels between the illumination images from the different positions.
  • Using photogrammetry to determine 3D coordinates for each matched pixel.
• Independent Claim 6 is similar but specifies capturing at least two pattern images (P1, P2) and two illumination images (I1, I2) from "slightly different offset locations."

III. The Accused Instrumentality

Product Identification

• The Medit i500, i600, i700, and i700 Wireless intraoral scanners, along with the accompanying Medit iScan and Medit Link software (collectively, the "iSeries") Compl. ¶1

Functionality and Market Context

• The iSeries products are handheld scanners used by dental professionals to perform "video-type scanning" of a patient's mouth, capturing 3D data to create digital models for dental restorations Compl. ¶8 Compl. Ex. 5, p. 177
• The complaint alleges the scanners operate using a "3-camera pattern," which consists of one projector and two high-speed cameras that use triangulation to acquire 3D images as the scanner is moved over the target surface Compl. Ex. 5, p. 177 An inspection report included with the complaint shows the physical arrangement of two imaging paths and a central projecting path in the i500 scanner Compl. Ex. 3, p. 87
• The complaint positions the i600 as a lower-cost version of the i700, sharing the same core components and software, and the i700 Wireless as a wireless version of the i700 Compl. ¶15

IV. Analysis of Infringement Allegations

'892 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
projecting a pattern onto the object from at least first and second positions;	The iSeries scanners are moved by hand during operation, projecting a pattern onto the teeth from a continuous sequence of different viewpoints, which constitutes at least a first and second position.	¶33	col. 7:41-43
observing the pattern from the first and second positions by capturing an image P of the pattern incident on the object;	During video-type scanning, the iSeries' two cameras capture images of the projected pattern on the object's surface from multiple positions as the scanner moves.	¶33	col. 7:44-47
capturing an illumination image I of the object from each of the first and second positions, wherein the image I is captured using an imaging system comprising a projection portion and one or more imaging portions;	The iSeries scanners, which contain a projector and two cameras, capture full-color illumination images of the object's surface at each scanning position.	¶33	col. 7:48-53
forming a 3D model of the object for each of the first and second positions by analyzing observed distortions to the pattern P caused by a 3D surface of the object;	The software processes the captured pattern images to generate 3D data, referred to as "RAW DATA," which represents the surface topography and constitutes a 3D model.	¶33	col. 7:54-57
using the 3D model in conjunction with each illumination image I to find a pixel in the illumination image I of the object from the first position that corresponds to a pixel in the illumination image I of the object from the second position, wherein the corresponding pixels are a matched pixel;	The initial 3D model ("RAW DATA") is used to facilitate the process of finding corresponding or "matched" pixels between the successive full illumination images captured from different positions.	¶33	col. 7:58-65
and using photogrammetry to determine 3D coordinates for each matched pixel.	After identifying matched pixels between illumination images, the system uses photogrammetry to calculate final 3D coordinates, which are compiled into the final "MESH DATA." A screenshot in the complaint shows the distinction between the initial "RAW DATA" and the final "MESH DATA" Compl. Ex. 5, p. 201	¶33	col. 7:66-67

• Identified Points of Contention:
  • Scope Questions: A central dispute may arise over the interpretation of "at least first and second positions." The defense may argue that this language requires discrete, static captures, raising the question of whether the continuous "video-type scanning" performed by the accused products falls within the claim's scope.
  • Technical Questions: The infringement theory depends on the accused software using an initial 3D model ("RAW DATA") to guide the search for matched pixels in the illumination images. A technical question for the court will be whether the accused process operates in this two-step manner as claimed, or if it uses a fundamentally different algorithm for generating the final 3D coordinates ("MESH DATA").

V. Key Claim Terms for Construction

• The Term: "at least first and second positions"
  • Context and Importance: This term is critical because the accused iSeries scanners operate by continuous movement ("video-type scanning"), while the patent specification often describes a process involving discrete captures at positions M1, M2, etc. Practitioners may focus on this term because its construction could determine whether a continuous scanning process can literally infringe a claim that appears to describe a sequence of discrete steps.
  • Evidence for a Broader Interpretation: The patent describes a general need to take images "from different positions" and speaks of a sequence of positions "M going from 1 through N," which could be argued to encompass any set of two or more distinct viewpoints, including consecutive frames in a video stream '892 Patent, col. 1:15-17 '892 Patent, col. 3:14-16
  • Evidence for a Narrower Interpretation: The specification details an algorithm for transforming point clouds (C_i) from the coordinate space of one position to another (T_i = Q * T_i-1), which may suggest a more structured, stop-and-start process rather than a continuous data stream '892 Patent, col. 4:1-9
• The Term: "using the 3D model...to find a pixel...that corresponds to a pixel"
  • Context and Importance: This step defines the core utility of the initial 3D model: to make pixel-matching easier. The dispute may turn on how the accused software actually "finds" corresponding pixels and whether it "uses" the initial 3D model in the manner claimed.
  • Evidence for a Broader Interpretation: The patent states that the initial 3D model helps "obviates a computationally expensive matching of pixels between different images," suggesting that any method using the initial model to constrain or guide the search for corresponding pixels would meet this element '892 Patent, col. 1:43-46
  • Evidence for a Narrower Interpretation: A defendant could argue this requires a specific search-and-match algorithm where the 3D model provides a direct lookup or a narrowly defined search area for a corresponding pixel, and that their software uses a more holistic or different data fusion technique that does not "find" pixels in this way '892 Patent, claim 1

VI. Other Allegations

• Indirect Infringement: The complaint alleges inducement of infringement based on Medit's marketing materials, user manuals, online videos, and technical support, which allegedly instruct and encourage distributors and end-users (e.g., dental clinics) to operate the iSeries scanners in an infringing manner (Compl. ¶34, Compl. ¶37; Compl. Ex. 5, Compl. ¶¶pp. 161-164). Contributory infringement is alleged on the basis that the iSeries scanners and their dedicated software are not staple articles of commerce and have no substantial non-infringing uses Compl. ¶35 Compl. ¶38
• Willful Infringement: Willfulness is alleged based on Medit's purported actual notice of the '892 patent since at least January 7, 2021, after which it allegedly made no attempt to design around the patent and continued its infringing activities Compl. ¶39

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

• A core issue will be one of process scope: can the claim term "at least first and second positions," which is described in the patent with reference to discrete captures, be construed to cover the continuous, high-frame-rate "video-type scanning" performed by the accused iSeries products?
• A key evidentiary question will be one of functional operation: does the accused Medit software perform the claimed two-step method of first "forming a 3D model" from structured light patterns and then "using" that specific model to guide the search for matched pixels in separate illumination images, or does it employ a fundamentally different, integrated algorithm for data capture and processing?
• Regarding damages and intent, the case may explore the effectiveness of notice: did the notice letter sent to a Medit distributor in early 2021 provide Medit with the requisite knowledge to support claims of willful and induced infringement for its subsequent conduct, and what, if any, were Medit's obligations to investigate potential infringement at that time?