CLO Virtual Fashion Inc v. Zhejiang Lingdi Digital Technology Co Ltd

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: CLO Virtual Fashion Inc. (South Korea)
  • Defendant: ZHEJIANG LINGDI DIGITAL TECHNOLOGY CO., LTD. (D/B/A LINCTEX) (People's Republic of China)
  • Plaintiff's Counsel: FENWICK & WEST LLP
• Case Identification: 2:23-cv-00274, E.D. Tex., 06/14/2023
• Venue Allegations: Venue is alleged on the basis that Defendant is not a resident of the United States and regularly conducts business in Texas, including making its products available for sale and download in the district.
• Core Dispute: Plaintiff alleges that Defendant's Style3D Studio, a 3D virtual garment design software, infringes three U.S. patents related to creating, simulating, and measuring digital clothing.
• Technical Context: The technology at issue involves computer-aided design for the fashion industry, specifically software tools that improve the accuracy and user experience of designing and simulating virtual 3D garments from 2D patterns.
• Key Procedural History: The complaint alleges that Defendant developed its competing software by studying unlicensed, "cracked" versions of Plaintiff's products. It also references legal proceedings initiated by Plaintiff against Defendant in China. Plaintiff alleges providing Defendant with notice of the asserted patents on June 7, 2023, one week prior to filing the complaint.

Case Timeline

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

U.S. Patent No. 10,733,773 - "Method and apparatus for creating digital clothing"

(Issued August 4, 2020; the "'773 Patent")

The Invention Explained

• Problem Addressed: In the context of "free sewing" for virtual garments, a user must manually define the length of two separate seam lines that will be joined. The patent identifies the difficulty and inefficiency a user faces in manually adjusting the length of one seam to precisely match the other, an inaccuracy that can lead to unrealistic wrinkles or other defects in the final 3D simulated garment Compl. ¶¶43-44 '773 Patent, col. 1:34-49
• The Patented Solution: The invention is a method to improve the usability of free sewing by providing automated assistance to the user Compl. ¶45 When a user defines the first seam segment and begins defining the second, the system detects the cursor's position and displays a "candidate ending point" on the second pattern piece that would make the second seam's length "substantially equal" to the first '773 Patent, abstract '773 Patent, col. 6:33-45 The system can also display the numerical difference in length between the seams and automatically move, or "snap," the cursor to the candidate point to aid the user in making an accurate selection '773 Patent, col.2:44-49
• Technical Importance: This technology streamlines the 3D garment design workflow by reducing manual adjustments and potential for user error, thereby increasing both the speed and accuracy of the virtual sewing process Compl. ¶45

Key Claims at a Glance

• The complaint asserts independent claim 1 Compl. ¶77
• The essential elements of claim 1 include:
  • Setting a first selected segment to be sewn on a pattern.
  • Setting a second selected segment, which includes inputting a starting point.
  • Detecting a current cursor position.
  • Displaying a candidate ending point on the second segment to make its length substantially equal to the first.
  • Connecting the starting point to a present point near the cursor to form a line.
  • Moving the present point to the candidate ending point if the cursor is close enough.
  • Displaying a difference value between the first segment's length and the line's length.
  • Selecting the present point as the ending point based on user input.
  • Setting the final second segment between the starting and ending points.

U.S. Patent No. 11,410,355 - "Method and apparatus for creating digital clothing"

(Issued August 9, 2022; the "'355 Patent")

The Invention Explained

• Problem Addressed: The '355 Patent shares a common specification with the '773 Patent and addresses the same technical problem: the inefficiency and potential for error when users manually match seam lengths in free sewing applications for virtual clothing design Compl. ¶38 '355 Patent, col. 1:38-49
• The Patented Solution: The solution is substantively similar to that of the '773 Patent, describing a method to assist the user by determining and moving to a candidate end point that matches the length of the first seam Compl. ¶45 A key distinction in the asserted claim of the '355 Patent is the addition of a specific user feedback mechanism: displaying the length and difference values in a first color when the lengths are substantially equal, and in a second, different color when they are substantially different, serving as an intuitive visual warning to the user '355 Patent, claim 1, elements [b.6] and [b.7]
• Technical Importance: The color-coded feedback provides an immediate and intuitive visual cue to the designer, enhancing the user interface and further reducing the cognitive load and potential for error in the virtual garment creation process Compl. ¶45

Key Claims at a Glance

• The complaint asserts independent claim 1 Compl. ¶99
• The essential elements of claim 1 are largely parallel to claim 1 of the '773 Patent, including steps for setting segments, determining a present point, moving it to a candidate ending point, and selecting an end point. It additionally requires:
  • Displaying the length and/or difference value in a first color when the second length is substantially equal to the first.
  • Displaying the length and/or difference value in a second color when the second length is substantially different from the first.

U.S. Patent No. 11,222,448 - "Method and apparatus for measuring measurement of two-dimensional pattern corresponding to three-dimensional virtual clothing"

(Issued January 11, 2022; the "'448 Patent")

Technology Synopsis

The patent addresses the problem that taking accurate measurements directly on a 3D virtual garment is difficult because fabric simulation can cause stretching, folding, or other distortions Compl. ¶58 '448 Patent, col. 1:29-47 The claimed solution is a method for taking more accurate measurements on the corresponding 2D flat patterns, including a process for measuring a single continuous line across multiple, physically separate 2D pattern pieces by accounting for the space between them Compl. ¶59 '448 Patent, abstract

Asserted Claims

Independent claim 1 is asserted Compl. ¶120

Accused Features

The complaint alleges that the "Point-to-Point Measure" function in the accused Style3D software infringes the '448 Patent Compl. ¶121 Compl. ¶122

III. The Accused Instrumentality

Product Identification

Defendant's virtual design program, Style3D Studio ("Style3D") Compl. ¶67

Functionality and Market Context

• Style3D is described as a software program for creating and designing digital clothing Compl. ¶10 Compl. ¶67 The complaint specifically identifies two features relevant to the infringement allegations. The first is a "Free Sewing" mode, which allows a user to define seam lines on 2D pattern pieces that will be virtually stitched together Compl. ¶79 The second is a "Point to Point Measure" function, which enables users to measure distances on 2D patterns, including across multiple separate pieces of a single garment design Compl. ¶121 Compl. ¶122
• The complaint positions Style3D as a direct competitor developed by copying Plaintiff's technology, including through the alleged use of over 50 unlicensed or "cracked" versions of Plaintiff's software in Defendant's research and development department Compl. ¶¶23-24 The complaint also provides visual evidence purporting to show Defendant using Plaintiff's proprietary 3D avatars in its own marketing materials Compl. ¶¶25-27 This image shows a side-by-side comparison of Plaintiff's avatar and the avatar used in Defendant's advertisement Compl. ¶27, pp. 9-11

IV. Analysis of Infringement Allegations

'773 Patent Infringement Allegations

'355 Patent Infringement Allegations

Identified Points of Contention

• Scope Questions: For the '773 and '355 Patents, a central question may be whether the term "moving the present point," as recited in the claims, can be read to cover the "snapping" of a cursor to a guide point Compl. ¶85 The defense may argue that "snapping" is a conventional and distinct UI behavior not contemplated by the patent's specific method.
• Technical Questions: For the '448 Patent, the complaint alleges that Style3D "determines and recognizes attributes of each digital 2D pattern piece" to enable measurement across gaps Compl. ¶123 A key technical question will be what evidence demonstrates that the accused software performs this specific step of "determining attributes" in the manner claimed, as opposed to using an alternative, non-infringing algorithm to achieve a similar visual result. The complaint's visual evidence, such as Figure 18, shows the output but not the underlying process Compl. ¶124, p. 41

V. Key Claim Terms for Construction

The Term: "moving the present point to the candidate ending point"

('773 Patent, claim 1[f])

• Context and Importance: This term describes an active, automated step performed by the system to assist the user. The complaint's infringement theory relies on equating this claimed step with the accused software's "snap" functionality Compl. ¶85 Practitioners may focus on this term because its construction will determine whether a common UI feature falls within the scope of what the patent claims as its invention.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The specification describes the function as "moving the cursor position to a position of the determined candidate for the ending point" '773 Patent, col. 2:45-47 This less specific language could be argued to encompass any automated relocation of the cursor or its logical point, including snapping.
  • Evidence for a Narrower Interpretation: The patent's flowchart in FIG. 2 presents "MOVE CURSOR POSITION" as a distinct step (S25) in a specific sequence '773 Patent, FIG. 2 A party might argue this implies a specific programmatic operation distinct from a generic, OS-level or application-framework-level cursor snapping feature.

The Term: "substantially equal"

('773 Patent, claim 1[d]; '355 Patent, claim 1[b.3])

• Context and Importance: This term defines the condition that the system uses to identify the "candidate ending point." The degree of precision required by this term is critical for determining infringement. The complaint provides evidence of a "0.00" difference, which would meet any definition, but the scope of the term will be contested for scenarios with small, non-zero differences Compl. ¶83 Compl. ¶105
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The patent's background explains that the problem arises from the difficulty of manual adjustment, where fabric that "stretches well" can hide inaccuracies '773 Patent, col. 1:40-43 This context may support a functional definition, where "substantially equal" means a difference small enough to avoid creating undesirable wrinkles in the simulated garment.
  • Evidence for a Narrower Interpretation: The specification repeatedly describes the goal as making the second segment "a same as a length of the first selected segment" '773 Patent, col. 2:37-38 This language suggests a more precise, near-identical mathematical relationship, which could support a narrower construction that allows only for de minimis variance like rounding errors.

VI. Other Allegations

• Indirect Infringement: The complaint alleges both induced and contributory infringement. For inducement, it states that Defendant provides instructions and tutorials on its website that teach users how to use the accused "Free Sewing" and measurement features in an infringing manner Compl. ¶89 Compl. ¶126 For contributory infringement, it alleges that the Style3D program is especially made for infringing use and has no substantial non-infringing uses Compl. ¶90 Compl. ¶127
• Willful Infringement: Willfulness is alleged based on Defendant's conduct after receiving actual notice of the patents-in-suit. The complaint states that a notice letter was sent on June 7, 2023, and details the subsequent delivery and acceptance of the letter by Defendant's representatives no later than June 14, 2023 Compl. ¶93 Compl. ¶130 Continued infringement after this date is alleged to be willful and deliberate.

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

• A core issue will be one of definitional scope: can claim terms like "moving the present point," which describe a specific step in the patented method, be construed to cover common and arguably conventional user interface behaviors such as "cursor snapping"? The outcome of this question will be pivotal in determining whether the accused features are simply standard software design or an implementation of the patented invention.
• A second key question will be one of technical proof: does the complaint's evidence, which consists primarily of screenshots of the accused software's user interface, provide a sufficient basis to infer that the underlying code performs the specific steps required by the claims? For the '448 patent in particular, the case may turn on whether Plaintiff can prove that the accused software "determines attributes of areas" to measure across pattern pieces, rather than employing a different, non-infringing mathematical approach.
• Finally, if infringement is established, a central dispute will involve willfulness and damages. The complaint's detailed allegations regarding Defendant's pre-suit notice and alleged use of "cracked" software to develop its product will frame the debate over whether any infringement was egregious and warrants enhanced damages.