SAUNDRA BROWN ARMSTRONG, Senior District Judge.
Plaintiff Tobii Technology AB ("Plaintiff"), a developer of eye gaze tracking technology, holds the rights to U.S. Patent No. 6,659,611 ("the '611 patent"). The patent discloses a system and method for eye gaze tracking using corneal image mapping. Plaintiff brings the instant patent infringement action against Defendant The Eye Tribe APS ("Defendant"), seeking a declaration that Defendant's products infringe the '611 patent. Dkt. 1. In turn, Defendant counterclaims for a declaration of non-infringement. Dkt. 27. The parties are presently before the Court for construction of the '611 patent claims. On November 19, 2015, the Court conducted a claims construction hearing. Each party appeared through counsel of record. Upon consideration of the parties' arguments and the claim construction briefs filed in connection with this matter, the Court finds as follows.
Eye gaze tracking technology allows a device or computer equipped with an eye tracker to determine where a user is looking. This makes it possible for users to interact with computers and machines using their eyes (as opposed to, or in addition to, using other input modalities, e.g., a keyboard, touchpad, or mouse).
Traditional "corneal reflection" gaze tracking systems "project light toward the eye and monitor the angular difference between pupil position and the reflection of a light beam from the cornea surface." '611 patent, col.1, ll.51-53. The light reflected from the eye has two major components—glint and retroreflection.
With regard to the '611 patent, a preferred embodiment of the invention "includes two uncalibrated cameras imaging the user's eye and having on-axis lighting." '611 patent, cover sheet. "The cameras capture images of a test pattern in real space as reflected from the user's cornea, which is essentially a convex spherical mirror. The invention then extracts parameters required to define a mathematical mapping between real space and image space, including spherical and perspective transformations. The invention processes subsequent images of objects reflected from the user's eye through the inverse of the mathematical mapping to determine a gaze vector and a point of regard."
Figures Four and Five, reproduced below, depict a preferred embodiment of the invention. '611 patent at figs. 4-5. This embodiment shows the user's eye (400), including the cornea (402), pupil (404), pupil center "P" (406), and glint "G" (408). The user's eye reflects a set of reference points (410) or "test pattern" (412). Also shown is at least one camera (500), including a focal center "F" (502), an image plane defining an image coordinate system (504), and an on-axis light source (not shown), as well as a display screen (510), preferably modeled as plane "S" (512). The point of regard "T" (508) falls at the intersection of the gaze vector (506) and the screen plane. The gaze vector bisects angel FPV, where "V" (514) represents a virtual light source whose reflection from the eye would appear to coincide with the pupil center in the image plane of the camera.
As is pertinent here, the '611 patent discloses three independent claims: Claims 1, 14, and 15. Claim 1 recites:
'611 atent, col.10, ll.6-21. Claim 14 tracks the language of Claim 1, except that the phrase "means for . . ." begins each element.
On December 18, 2013, Plaintiff initiated the instant infringement action against Defendant, alleging that Defendant's products infringe one or more the '611 patent claims, including Claim 14. Compl., Dkt. 1. Defendants answered and filed a counterclaim, denying infringement. Am. Answer & Countercl., Dkt. 27. On December 23, 2014, the parties filed a Joint Claim Construction and Prehearing Statement. Dkt. 49. The parties subsequently amended the Joint Statement, Dkt. 53, and filed their respective claim construction briefs, Pl.'s Opening Br., Dkt. 54; Def.'s Response Dkt. 56; Pl's Reply, Dkt. 57. A claim construction hearing was initially set for May 2015; however, the parties later stipulated to continue the same.
On October 6, 2015, the parties filed an Amended Joint Claim Construction and Prehearing Statement ("Joint Statement"), narrowing their disputes. Dkt. 86. In the operative Joint Statement, the parties dispute the construction of the terms and phrases: (1) "reference points"; (2) "image aspects"; and (3) "said image having image aspects in an image coordinate system and including reflections of said reference points." The parties also dispute the definiteness of elements in Claims 14 and 15, disagreeing as to whether the patent provides corresponding structure for the functions disclosed therein.
On November 19, 2015, the Court held a claims construction hearing. After discussion with the Court and each other, the parties agreed on the record to the following:
1. "Reference points" is construed to mean "points that form a test pattern";
2. "Image aspects" is construed to mean "features of the corneal image"; and
3. "Said image having image aspects in an image coordinate system and including reflections of said reference points" requires no construction. The Court adopted the parties' constructions as to the terms and phrases above. The parties submitted the issue of indefiniteness on their briefs.
The parties dispute the validity of Claim 14, which contains five elements, three of which are at issue.
A patentee may express an element of a claim "as a means or step for performing a specified function without the recital of the structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof." 35 U.S.C. § 112, ¶ 6;
Construing a means-plus-function claim is a two-step process.
A party alleging that the specification fails to disclose sufficient corresponding structure must make that showing by clear and convincing evidence.
Where, as here, a claimed function "is performed by a general purpose computer or microprocessor, then the specification must also disclose the algorithm that the computer performs to accomplish that function."
With these principles in mind, the Court considers each disputed element in turn.
Claim 14 describes a "means for defining a mathematical relationship between said reference coordinate system and image coordinate system." '611 patent, col.11, ll.7-9. The parties agree that the claimed function is "defining a mathematical relationship between the reference coordinate system and image coordinate system." The parties propose the following constructions of the claimed structure:
The Court finds that the specification fails to disclose corresponding structure for the function at issue. Although capable of expression in many forms, an algorithm must be a "step by step procedure" for performing the claimed function.
For example, Plaintiff primarily relies on the portion of the specification that states, "The invention maps or mathematically relates the test pattern image in the camera image coordinate systems to the actual test pattern through spherical and perspective transformation." Opening Br. at 15-16 (quoting '611 patent, col.4, ll.43-49). "Merely using the term [`spherical and perspective transformation'] does not disclose an algorithm— i.e., a step-by-step procedure—for performing the claimed function."
Plaintiff further relies on the assertion that articles incorporated by reference into the `611 patent "describe, to one of skill in the art, the structure of the claimed function." Opening Br. at 16. Specifically, Plaintiff directs the Court's attention to "the Zhang article," entitled "A Flexible New Technique for Camera Calibration."
Finally, Plaintiff asserts that the parties simply "disagree regarding the sufficiency of the disclosure," and that Defendant has failed to meet its burden of proving that one of ordinary skill in the art would not understand the disclosure of structure in the specification. Reply at 11 (citing
Claim 14 describes a "means for mapping said aspects from said image coordinate system to said reference coordinate system." '611 patent, col.11, ll.10-12. The parties agree that the claimed function is "mapping the image aspects from the image coordinate system to the reference coordinate system." The parties propose the following constructions of the claimed structure:
The Court finds that the specification fails to disclose corresponding structure for the function at issue. Plaintiff asserts that the structure is "a computer programmed to apply the mathematical relationship" defined in the prior element of Claim 14. Opening Br. at 17. In support of this construction, Plaintiff directs the Court's attention to several portions of the specification that explain, in various permutations, "Once the invention defines the mapping . . . the invention applies the mapping to subsequent images reflected from the user's cornea." Opening Br. at 17 (quoting '611 patent, col.5, ll.1-4 (emphasis added)). A means for "applying" a mathematical relationship, however, does not constitute an algorithm. This language says nothing about how the software performs this function. "As such, the language `describes an outcome, not a means for achieving that outcome.'"
Claim 14 describes a "means for computing a point of regard from said mapped image aspects." '611 patent, col.11, ll.13-14. The parties agree that the claimed function is "computing a point of regard from the mapped image aspects." The parties propose the following constructions of the claimed structure: Plaintiff: "[A] computer programmed to (a) determine an angle between the focal center, a
Whether the specification discloses sufficient corresponding structure for computing a point of regard from the mapped image aspects is not immediately apparent. On the one hand, Plaintiff cites passages of the specification that appear to describe an algorithm for computing a point of regard. Essentially, the invention maps point V, which represents a virtual light source corresponding to the pupil center of the reflected corneal image.
As Plaintiff acknowledges, however, the invention "can compute the point of regard" only "[a]s long as a mapping between the reference coordinate system and the target coordinate system exists." Opening Br. at 17 (quoting '611 patent, col.7, ll.23-26). Thus, computation of a point of regard relies on the prior elements that define and apply the mathematical relationship between the reference coordinate system and image coordinate system. As stated above, the patent fails to provide corresponding structure for the defining and applying functions.
In any event, the Court need not decide whether the patent provides sufficient structure for the claimed function of "computing a point of regard from the mapped image aspects." "When the specification discloses an algorithm that only accomplishes one of multiple identifiable functions performed by a means-plus-function limitation, the specification is treated as if it disclosed no algorithm."
Accordingly, the Court finds that Claim 14 in indefinite.
The parties dispute the validity of Claim 15, disagreeing as to whether means-plus-function treatment is applicable.
Use of the word "means" in a claim gives rise to a rebuttable presumption that the patentee intended to invoke means-plus-function treatment, and thus, that Section 112, ¶ 6 applies.
The presumption in favor of means-plus-function treatment is rebuttable in two ways.
Here, Claim 15's elements use the phrase "a . . . code means. . . ." Plaintiff contends that computer code constitutes sufficient structure for performing each of the recited functions, and therefore, that the presumption in favor of means-plus-function treatment is rebutted. Defendant argues that code does not constitute sufficient structure for performing each of the recited functions, and therefore, that Section 112, ¶ 6 applies.
The Court finds that Claim 15 is a means-plus-function limitation. "Although [code] represent[s] structure (in the form of software), it is not sufficient structure to perform the entirety of the function."
The cases cited by Plaintiff in support of the proposition that "code" constitutes sufficient structure are inapposite. In those cases, the claims at issue did not use the term "means."
Accordingly, having determined that Claim 15 is subject to means-plus-function treatment, the Court finds that Claim 15 (like Claim 14) is indefinite.
For the reasons stated above,
IT IS HEREBY ORDERED THAT:
1. The term "reference points" means "points that form a test pattern."
2. The term "image aspects" means "feature of the corneal image."
3. The phrase "said image having image aspects in an image coordinate system and including reflections of said reference points" requires no construction.
4. Claims 14 and 15 are invalid as indefinite for failing to disclose structure corresponding to the claimed functions.
5. The parties shall appear for a telephonic Case Management Conference on
IT IS SO ORDERED.