By Dennis Crouch
Brilliant Instruments v. GuideTech (Fed. Cir. 2013), Majority Opinion by Judges Moore and Reyna with Judge Dyk dissenting in part.
Shalom Kattan was a prolific inventor while an employee at GuideTech. When he left to form his own company, Brilliant Instruments, GuideTech threatened Kattan with charges of patent infringement. In 2009, Brilliant sued GuideTech for declaratory judgment of non-infringement. Patent Nos. 6,226,231, 6,091,671, and 6,181,649. In the litigation, district court judge Wilken sided with Brilliant and issued a summary judgment order of non-infringement. In a split decision, the Federal Circuit has reversed-in-part -- holding that GuideTech still has an infringement argument under the doctrine of equivalents.
The patent statute defines direct infringement liability for someone who "makes, uses, offers to sell, or sells any patented invention" without authority of the patent holder. For more than 150 years courts have seen the "patented invention" as being roughly defined by the patent's claims and infringement occurs when someone's unauthorized activities include each element of a patent claim. Using its common law power, the Supreme Court long ago expanded the scope of infringement beyond the literal confines of claim elements in order to also capture "equivalents." Thus, even if outside of the literal scope of a written claim, an accused infringer may still be liable if its activity is deemed equivalent to the claimed invention. In Warner-Jenkinson Company, Inc. v. Hilton Davis Chemical Co., 520 U.S. 17 (1997), the Supreme Court severely limited power of the doctrine of equivalents by ruling that the equivalents test must be done on an element-by-element basis rather than by focusing on the claim as a whole. In that case, the Supreme Court wrote:
In our view, the particular linguistic framework used [for the Doctrine of Equivalents] is less important than whether the test is probative of the essential inquiry: Does the accused product or process contain elements identical or equivalent to each claimed element of the patented invention? Different linguistic frameworks may be more suitable to different cases, depending on their particular facts. A focus on individual elements and a special vigilance against allowing the concept of equivalence to eliminate completely any such elements should reduce considerably the imprecision of whatever language is used. An analysis of the role played by each element in the context of the specific patent claim will thus inform the inquiry as to whether a substitute element matches the function, way, and result of the claimed element, or whether the substitute element plays a role substantially different from the claimed element. With these limiting principles as a backdrop, we see no purpose in going further and micromanaging the Federal Circuit's particular word choice for analyzing equivalence. We expect that the Federal Circuit will refine the formulation of the test for equivalence in the orderly course of case-by-case determinations, and we leave such refinement to that court's sound judgment in this area of its special expertise.
In this case, the claim at issue requires a shunt and a capacitor that is "operatively disposed in parallel" to a "first current circuit." The accused product also includes a capacitor but it is actually within the first circuit rather than parallel to the first circuit. Thus, there was no literal infringement. However, the patentee's technical expert analysis (available for the summary judgment) walked through the function-way-result test approved by Warner-Jenkinson and explained his opinion of infringement. The expert had explained:
[D]isposition of the shunt and the capacitor with respect to the [accused] first current circuit ... is equivalent to the electrical disposition of the shunt and the capacitor with respect to the [claimed] first current circuit ... because it performs substantially the same function (allowing the shunt to control the path of current flow to or from the first current circuit) in substantially the same way (wherein an electrical path from the first current circuit can be traced to either the capacitor or the shunt) to achieve substantially the same result (providing an electrical relationship wherein, e.g., the shunt can direct current to flow from the first current circuit to the second current circuit or from the first current circuit to the capacitor).
On appeal, the Federal Circuit found that that this "detailed application of the function-way-result test to the claim element and the allegedly equivalent feature of the accused product is sufficient to create a genuine issue of material fact for the jury to resolve." (Like direct infringement, infringement under the doctrine of equivalents is a question of fact typically decided by a jury.)
One aspect of the doctrine of equivalents is the vitiation rule -- stating that the DOE may not be used in a way that renders a claim term meaningless. However, almost since its introduction, the Federal Circuit has been rolling-back the doctrine. In the recent case of Deere & Co. v. Bush Hog, LLC, _ F.3d _ (Fed. Cir. 2012), the court wrote that
"Vitiation" is not an exception to the doctrine of equivalents, but instead a legal determination that "the evidence is such that no reasonable jury could determine two elements to be equivalent." The proper inquiry for the court is to apply the doctrine of equivalents, asking whether an asserted equivalent represents an "insubstantial difference" from the claimed element, or "whether the substitute element matches the function, way, and result of the claimed element." If no reasonable jury could find equivalence, then the court must grant summary judgment of no infringement under the doctrine of equivalents.
[T]he vitiation test cannot be satisfied by simply noting that an element is missing from the claimed structure or process because the doctrine of equivalents, by definition, recognizes that an element is missing that must be supplied by the equivalent substitute.
Vitiation is generally used when the claim element is the "polar opposite" of the accused equivalent. However, even there vitiation is simply a shorthand mechanism for saying that the two elements are "not insubstantially different." Here, Judge Moore adds to the explanation from Deere:
The vitiation test cannot be satisfied merely by noting that the equivalent substitute is outside the claimed limitation's literal scope. Rather, vitiation applies when one of skill in the art would understand that the literal and substitute limitations are not interchangeable, not insubstantially different, and when they do not perform substantially the same function in substantially the same way, to accomplish substantially the same result. In short, saying that a claim element would be vitiated is akin to saying that there is no equivalent to the claim element in the accused device based on the well-established "function-way-result" or "insubstantial differences" tests.
Judge Moore goes on to open the door for even polar opposites to be equivalents -- noting that proving equivalents "will be more difficult when the accused structure has an element that is the opposite of the claimed element, especially where the specification or prosecution history highlights the differences."
Applying these concepts to the facts of this case, we conclude that summary judgment must be reversed. The element at issue is: "wherein said shunt and said capacitor are operatively disposed in parallel with respect to said first current circuit." ... Everyone agrees that the capacitor in the accused device is not located in exactly the same place as the claimed capacitor, but is the change in location an insubstantial difference? We conclude that, viewing all factual inferences in favor of GuideTech, it has created a genuine issue of material fact which precludes summary judgment.
On remand, the equivalents question should then go to the jury.
In dissent, Judge Dyk argued that the expert report did not actually consider equivalents on a limitation-by-limitation basis as required by Warner-Jenkinson.