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Kim v. ConAgra Foods

decided on September 20, 2006 by the Court of Appeals for the Federal Circuit

review by J. Matt Buchanan | published July 18, 2017 | updated February 17, 2018

tags: claim construction, recapture, evidence, functional language, claim differentiation, object of the invention, pro se

In Kim v. ConAgra Foods, the Court of Appeals for the Federal Circuit issued a decision of a 2-1 panel that split solely on a claim construction issue. Other issues addressed by the Court include sufficiency of evidence of infringement for claims that require functionality, and the proper test for determining whether a surrender has occurred in a recapture analysis.

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claim construction | object of the invention | claim differentiation

Object of the invention not imported into claims where specification fails to necessarily require the stated object

The patent at issue, RE 36,355, is a reissue of US 5,510,129. Independent claims 5 and 10 were asserted against ConAgra, each of which is directed to "a potassium bromate replacer composition."

Claim 5, which, for the purposes of this review, is representative, reads:

A potassium bromate replacer composition consisting essentially of, by weight:

(a) about 0.001 to 0.03 parts ascorbic acid as an oxidant per 100 parts flour,

(b) about 0.015 to 0.2 parts food acid per 100 parts flour, said food acid selected from the group consisting of acetic acid, citric acid, fumaric acid, lactic acid, malic acid, oxalic acid, phosphoric acid, succinic acid, tartaric acid, fruit juice, fruit juice concentrate, vinegar, wine, and mixtures thereof, and

(c) flour.

The claim is purely compositional in nature; it includes no functional language on its face. Nevertheless, the Court adopted a claim construction that injected functional language into the claim based on the preamble term 'potassium bromate replacer composition.'

Kim sought an interpretation of "potassium bromate replacer" that would, in essence, read on any substance meeting the compositional limitations of the claim. The Court skipped the preamble issue altogether, and went directly to a Phillips-based construction analysis. First, the Court observed the absence of an explicit definition for the term in the specification, but noted that the specification makes it clear that the claimed composition "functions as an oxidant and that oxidants strengthen dough, increase loaf volume, and contribute to fine crumb grain."

Reading the claim against the backdrop of the specification, the Court concluded that "the potassium bromate replacer must be functional" and that a mere substitute composition would not be covered.

The Court declined, however, to read a listed "object of the invention" into the claim, noting that "[t]he mere fact that one object of the invention is to produce a slow acting oxidant which is functional throughout the entire manufacturing process does not mean that this particular feature was adopted as a limitation in each claim of the patent. The specification does not require that the potassium bromate replacer must necessarily be a slow acting oxidant, only that particular potassium bromate replacers perform that function." (emphasis in original).

The Court noted that the doctrine of claim differentiation supports its decision not to read the listed Object of the invention into the claims. The listed Object, a "slow acting" oxidant, is presented as an added limitation in Claim 7, which depends from independent Claim 5. Reading that limitation into Claim 5 would render Claim 7 redundant in violation of the doctrine.

In concluding the Phillips-based analysis, the Court noted the absence of anything in the prosecution history of the patent that would "compel a different construction."

Judge Schall, writing in dissent and addressing only the claim construction issue, would construe the term "potassium bromate replacer" to refer to "a slow acting oxidant that is functional throughout the entire manufacturing process."

In essence, Judge Schall would adopt a claim construction that reads the stated object of the invention into the claim via the term "potassium bromate replacer." It's important to note, though, the Judge Schall's would-be construction is not based simply on the fact that an "object of the invention" was provided in the specification. Rather, Judge Schall believes that the inventor, here, acted as her own lexicographer and defined the term "potassium bromate replacer" to include the "slow acting..." language. Judge Schall notes numerous examples in the specification, of which the stated Object of the Invention is but one, that support his argument that the inventor defined the term to include the "slow acting" language.

"Thus, from the beginning of the patent in the Abstract through the Detailed Description, Kim consistently defined 'potassium bromate replacer' as a 'slow acting oxidant that is functional throughout the entire manufacturing process.'"

Judge Schall also finds the prosecution history helpful for his would-be construction. Interestingly, the dissent does not address the claim differentiation argument noted by the majority.

infringement | functional language | evidence

Patentees should consider functional testing evidence if there is any possibility that a claim could be construed to include one or more functional limitations, even if only after a Federal Circuit de novo review

In rejecting an inducement of infringement argument, the Court noted that "Kim again did not conduct any test based on the accused product to determine whether those ingredients had the required effect."

In essence, the Court needed sufficient evidence on the record to determine if the requisite underlying act of infringement existed. By adopting the claim construction that required a functional limitation, the Court needed to know whether the 'replacer' in the accused products had the required effect. Since no functional testing was conducted, the evidence was sufficient to support the jury verdict of noninfringement.

From a litigation perspective, this presents patentee's with a challenge:

In short, if there is any possibility that a claim could be construed to include one or more functional limitations, even if only after a Federal Circuit construction, the patentee needs to consider whether functional testing should be conducted and whether evidence of such testing should be entered.


Proper focus of recapture analysis is on objective observer, not subjective intent

The Court also addressed the question of whether the patentee recaptured surrendered subject matter via the reissue process.

The recapture issue at hand, though, was whether a surrender had occured. The district court suggests that the patentee's subjective intent shoud be evaluated in determining whether a surrender was made for purposes of a recapture analysis.

The Federal Circuit, in stating the proper recapture analysis, flatly rejected this 'subjective intent suggestion' of the district court in favor of the 'objective observer' inquiry:

"It is clear that in determining whether 'surrender' of subject matter has occurred, the proper inquiry is whether an objective observer viewing the prosecution history would conclude that the purpose of the patentee's amendment or argument was to overcome prior art and secure the patent…. [I]f the objective public observer can discern a surrender of subject matter during the prosecution of an original patent in order to overcome prior art and obtain the patent, then the recapture rule should prevent the reissuing of that patent to claim the surrendered subject matter." (emphasis added)

pro se

Pro se applicant not treated differently from other patentees

The Court flatly rejected an argument that a pro se patent applicant should be treated differently than one represented by counsel for recapture purposes. Even here, where the patent Examiner entered a significant narrowing amendment following an interview with the Applicant, the Court finds no reason to treat such applicants differently under the law.