DCT

2:18-cv-01681

Tobii Ab v. Beijing 7Invensun Technology Co Ltd

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:18-cv-01681, D. Nev., 01/03/2019
  • Venue Allegations: Plaintiff alleges venue is proper in any judicial district because the Defendant is a foreign corporation with its principal place of business in Beijing, China.
  • Core Dispute: Plaintiff alleges that Defendant’s eye-tracking module for virtual reality headsets infringes a patent related to determining eye gaze by mapping reflections of reference points from a user's cornea.
  • Technical Context: The technology concerns eye-gaze tracking, a key interface for human-computer interaction, with applications in accessibility, research, and increasingly, virtual and augmented reality systems.
  • Key Procedural History: This filing is an Amended Complaint. The complaint alleges that the original complaint was sent to the Defendant via e-mail on September 19, 2018, establishing a date of alleged knowledge for the purposes of willful infringement.

Case Timeline

Date Event
2001-12-28 Priority Date for U.S. Patent No. 6,659,611
2003-12-09 U.S. Patent No. 6,659,611 Issues
2018-01-01 Defendant allegedly used accused product at CES show
2018-09-19 Original complaint allegedly sent to Defendant via e-mail
2019-01-03 Amended Complaint Filed

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

U.S. Patent No. 6,659,611 - “System and Method for Eye Gaze Tracking Using Corneal Image Mapping,” Issued December 9, 2003

The Invention Explained

  • Problem Addressed: The patent describes prior art eye-tracking systems as often being expensive, complicated to install, and requiring a disruptive, user-specific calibration process before each session (e.g., requiring a user to follow a cursor across a screen) (U.S. Patent No. 6,659,611, col. 2:40-50). This calibration requirement makes such systems unsuitable for non-cooperative subjects like infants or for applications where immediate, seamless use is desired (’611 Patent, col. 3:25-31).
  • The Patented Solution: The invention proposes a method to track eye gaze without this type of active user calibration. It works by first creating a set of known "reference points" in a coordinate system (e.g., infrared LEDs around a monitor) (’611 Patent, col. 14:10-13). A camera then acquires an image of the user’s cornea, which includes reflections of these reference points (’611 Patent, col. 14:14-18). The system then defines a "mathematical relationship" that maps the distorted reflections in the camera's image back to the known positions of the reference points in the real world (’611 Patent, col. 14:19-20). Once this mapping is established, it can be used on subsequent images to compute the user's "point of regard" from other image features, like the pupil center, without further calibration (’611 Patent, col. 14:27-30; FIG. 7).
  • Technical Importance: This approach sought to create a "calibration-free" system, which could increase user convenience and significantly broaden the acceptance and application of eye-gaze tracking technology (’611 Patent, col. 4:1-9).

Key Claims at a Glance

  • The complaint asserts independent claim 1 and dependent claims 2-3, while reserving the right to assert claims 1-13 (Compl. ¶9, ¶25).
  • Independent Claim 1 recites a method with the following essential elements:
    • creating a set of reference points in a reference coordinate system;
    • acquiring at least one image of at least one of a user's corneas, said image having image aspects in an image coordinate system and including reflections of said reference points;
    • defining a mathematical relationship between said reference coordinate system and said image coordinate system;
    • mapping said image aspects from said image coordinate system to said reference coordinate system using said mathematical relationship; and
    • computing a point of regard from said mapped image aspects.

III. The Accused Instrumentality

Product Identification

The accused product is Defendant's "aGlass DK II" eye tracking module (Compl. ¶10). The complaint notes this module can be installed in devices such as the HTC Vive virtual reality headset (Compl. ¶29).

Functionality and Market Context

The aGlass DK II is an eye-tracking module that allegedly performs a method for eye gaze tracking (Compl. ¶22). The complaint alleges the module includes "a set of controlled light sources around said screen" which serve as reference points (Compl. ¶28). The complaint provides screenshots from the defendant's website, www.aglass.com/product, to identify the accused product (Compl. ¶4.E). The complaint alleges Defendant used the product at the CES show in January 2018 and encouraged participants to use it, suggesting a market context that includes developers and industry partners (Compl. ¶12, ¶14).

IV. Analysis of Infringement Allegations

The complaint references a claim chart in Exhibit F, which was not publicly filed with the complaint. The infringement theory is therefore summarized from the narrative allegations in the complaint body.

Plaintiff alleges that the aGlass DK II module performs a method for eye gaze tracking that meets every step of claim 1 of the ’611 Patent (Compl. ¶22). The complaint alleges that the module "creates a set of reference points in a reference coordinate system" (Compl. ¶23) and "acquires at least one image of at least one of a user's corneas" that includes reflections of those points (Compl. ¶24). It further alleges the module "defines a mathematical relationship" between the coordinate systems (Compl. ¶25), "maps said image aspects" using that relationship (Compl. ¶26), and "computes a point of regard" from the results (Compl. ¶27). For dependent claim 2, the complaint alleges the reference points are a "set of controlled light sources around said screen" (Compl. ¶28). For dependent claim 3, it alleges the HTC Vive in which the module is installed includes a "screen that is a computer monitor" (Compl. ¶29).

Identified Points of Contention

  • Technical Question: The complaint provides conclusory allegations that each claim step is met, with citations to the non-public Exhibit F. A central question will be what evidence Plaintiff possesses to demonstrate that the accused module's internal software actually performs the specific steps of "defining a mathematical relationship" and "mapping...image aspects" in the manner claimed by the patent.
  • Scope Question: A key issue may be whether the "screen" in a virtual reality headset like the HTC Vive, which is inches from the user's eyes, qualifies as the "screen" contemplated by the patent, whose embodiments often depict a standard computer monitor at a distance from the user (e.g., ’611 Patent, col. 6:45, "display screen perimeter").

V. Key Claim Terms for Construction

The Term: "reference points"

Context and Importance

This term is foundational to the entire claimed method. The definition will determine what can serve as the basis for the "mathematical relationship"—e.g., physical lights, a pattern on a screen, or something else. Its construction is critical for determining whether the accused device's method falls within the scope of the claims.

Intrinsic Evidence for Interpretation

  • Evidence for a Broader Interpretation: Dependent claim 2 provides a non-exhaustive list of what "reference points" can include, such as "a printed pattern," "an unobtrusively interlaced pattern in said screen," "content displayed in said screen," and "a set of controlled light sources." (’611 Patent, col. 14:21-26). Plaintiff may argue this list demonstrates the term in independent claim 1 is meant to be broad and not limited to any single embodiment.
  • Evidence for a Narrower Interpretation: The specification's detailed description of a preferred embodiment repeatedly refers to "a set of point light sources deployed around a display screen perimeter" (’611 Patent, col. 6:44-46). Defendant may argue that the invention is properly understood in this context and the term should be construed more narrowly than Plaintiff proposes.

The Term: "defining a mathematical relationship"

Context and Importance

This term describes the core computational step of the invention. The infringement analysis will depend heavily on whether the specific algorithm used by the aGlass DK II constitutes "defining a mathematical relationship" as taught in the patent.

Intrinsic Evidence for Interpretation

  • Evidence for a Broader Interpretation: Claim 11 states the mathematical relationship can include "spherical transformations, perspective transformations, polynomial interpolation," suggesting the term is not limited to one specific type of calculation (’611 Patent, col. 14:56-59).
  • Evidence for a Narrower Interpretation: The detailed description explains the mapping in the context of a specific geometric model that involves determining a gaze vector by "bisection of angle FPV" as depicted in Figure 5 (’611 Patent, col. 8:3-5). A defendant could argue this detailed disclosure limits the scope of the term to this type of geometric modeling or a close equivalent.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges induced infringement, stating Defendant "knowingly instructs and directs users/customers" to use the aGlass DK II in an infringing manner, citing the provision of "Quick Instructions" and a user manual (Compl. ¶32, ¶37). It also alleges contributory infringement, asserting that the aGlass DK II module has "no substantial non-infringing use" (Compl. ¶11, ¶36).
  • Willful Infringement: The willfulness allegation is based on alleged continued infringement after Defendant gained knowledge of the ’611 Patent. The complaint pleads this knowledge occurred "no later than the filing date of the original Complaint," which was allegedly sent to Defendant by e-mail on September 19, 2018 (Compl. ¶35, ¶40).

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

  1. A central issue will be one of claim construction and scope: Can the term "screen", as used in the patent's claims and described in its specification in the context of desktop monitors, be construed to read on the near-eye displays of a virtual reality headset? The resolution of this question may significantly impact the infringement analysis for the accused system.
  2. A key evidentiary question will be one of technical proof: Since the core of the invention lies in a specific computational method ("defining a mathematical relationship"), the case will likely depend on what discovery reveals about the accused product's source code and algorithms. The primary dispute will be whether the accused method is merely an alternative way to track gaze or if it operates on the specific principles of mapping corneal reflections of known reference points as claimed in the ’611 Patent.