The court here has solidified its technically dicta discussion in Deere v. Bush Hog a couple months ago attempting to curb what it sees as an abuse of the vitiation doctrine when considering equivalency. The proper inquiry under the doctrine of equivalents, according to the court, is simply 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.” For “vitiation” to apply and bar equivalency, the element at issue must really be the “antithesis” of the claimed structure.
Background / Facts: The patents here generally relate to circuits that measure the timing errors of digital signals in high-speed microprocessors. These circuits, which are referred to as time interval analyzers, detect timing errors by analyzing a digital circuit’s clock signal and output signals. The claims recite a capacitor “operatively disposed in parallel” with respect to a first current circuit. it was undisputed that the capacitor in the accused products was part of the first current circuit and therefore could not literally be arranged in parallel with the first current circuit, but the patentee argued that the operation of the accused products was equivalent to operatively disposing the capacitor in parallel with respect to the first current circuit.
Issue(s): Whether application of the doctrine of equivalents would vitiate the requirement that the claimed “first current circuit” and the “capacitor” be separate elements.
Holding(s): No. “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.”