The patent in this case relates to breadmaking. Oxidizing agents are used during the breadmaking process to strengthen dough, increase loaf volume, contribute to fine crumb grain, and increase shelf life. Since the early 1900's, potassium bromate was widely used as a slow-acting oxidant to improve the quality of bread. However, by the 1990's, there was growing concern about the carcinogenic effects of potassium bromate, and the Food and Drug Administration encouraged the baking industry to seek suitable alternatives. Kim, a food chemist, believed that a combination of ascorbic acid and food acid would serve as a suitable alternative to potassium bromate in the breadmaking process, and applied for a patent on that composition. On April 23, 1996, Kim obtained U.S. Patent No. 5,510,129 for a potassium bromate replacer composition. However, a few weeks later, Kim surrendered that patent to the Patent and Trademark Office ("PTO") and filed a reissue application, alleging that an error had arisen during prosecution. After prosecution of her reissue application, Kim obtained the '355 reissue patent on October 26, 1999.

Kim, pro se prosecutor and owner of Reissue 36,355, sued ConAgra Foods for inducing infringement in its bread making recipes.

On April 9, 2001, Kim filed suit against ConAgra alleging that ConAgra induced the infringement of independent claims 5 and 10 of the reissued '355 patent.1 Claims 5 and 10 were newly added during prosecution of the reissue application. The accused conduct was that ConAgra required licensees of its "Healthy Choice®" brand name to use recipes provided by ConAgra. Kim alleged that the Healthy Choice® Natural Wheat product infringed claim 5 and that the Healthy Choice® 7-Grain and Whole Grain products infringed claim 10. ConAgra stipulated that the bread recipes used in the accused products included ascorbic acid and food acid in the ranges specified in claims 5 and 10 of the '355 patent. Claim 10 differs from claim 5 in that it contains the additional limitation of yeast.

Kim got a slim win on a single claim, infringement on claim 10, in the jury verdict, but then the district court ruled JMOL that claim 10 was not infringed. Kim appealed (CAFC 05-1414), to no avail.

Claim Construction

The claim construction was narrower than Kim wanted, but not as narrow as ConAgra wished. Basically, the claimed "potassium bromate replacer" was construed as an oxidizing agent. Kim's specification was the guide.

As part of its claim construction, the district court instructed the jury that "[t]o infringe one of the claims of the '355 Patent, a bread must (a) contain ingredients in the proportions in claim 5, 6, 7, 8, or 10 and, (b) in that particular bread, the ingredients must act as a potassium bromate replacer, that is, the ingredients must perform essentially the same function in the production of that bread as would potassium bromate." J.A. at 113 (emphasis added). The court also provided the jury with the following definition: "Potassium Bromate is a slow acting oxidant once commonly used in the breadmaking process. Its function in the breadmaking process is to strengthen the dough, increase loaf volume, and contribute to fine crumb grain." J.A. at 147 (emphasis added). Kim objected to these jury instructions. On appeal, Kim concedes that "potassium bromate replacer" is a claim limitation, but argues that a "potassium bromate replacer" is simply a "potassium bromate substitute," which she in turns describes as a composition that is present when potassium bromate is not.

Upon review of the specification, we agree with the district court's claim construction. "[C]laims must be read in view of the specification, of which they are a part." Phillips v. AWH Corp., 415 F.3d 1303, 1315 (Fed. Cir. 2005) (en banc) (internal quotation marks omitted). The specification "is the single best guide to the meaning of a disputed term." Id. (internal quotation marks omitted). Here, while the specification does not explicitly define the term "potassium bromate replacer," it does make clear that the claimed potassium bromate replacer is an oxidizing agent. In fact, the specification explicitly states that "the potassium bromate replacer provided in the present invention is a more effective oxidant than potassium bromate."

Claim differentiation was a significant factor in determining claim scope.

The 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. '355 patent, col. 2. ll. 25-33. Thus the fact that the patent here discloses the advantages of a slow acting oxidant does not mean that all the claims are directed to such an oxidant. See E-Pass Tech., Inc. v. 3Com Corp., 343 F.3d 1364, 1368-69 (Fed. Cir. 2003). Indeed, Kim chose to claim a "slow acting" oxidant in dependent claim 7, while her independent claims were directed to a more general potassium bromate replacer. The doctrine of claim differentiation suggests that the independent claims here should not include explicit limitations of a dependent claim. See Phillips, 415 F.3d at 1315 ("[T]he presence of a dependent claim that adds a particular limitation gives rise to a presumption that the limitation in question is not present in the independent claim."); Liebel-Flarsheim Co. v. Medrad, Inc., 358 F.3d 898, 910 (Fed. Cir. 2004).

Infringement

Kim appealed the JMOL of noninfringement of claims 10 and 5. She had charged inducement. Kim's problem was that she, while herself an expert, hadn't backed her assertion with substantiating evidence.

"A finding of inducement requires both an underlying instance of direct infringement and a requisite showing of intent." Fuji Photo Film Co. v. Jazz Photo Corp., 394 F.3d 1368, 1377 (Fed. Cir. 2005).

It was undisputed that the accused products included the amount of ascorbic acid, food acid, and yeast in the proportions listed in claim 10. The question was whether the claimed ingredients in the accused products satisfied the functionality limitations. Kim's evidence of infringement on the question of functionality was by analogy. She testified that her patented composition strengthened dough, increased loaf volume, and contributed to fine crumb grain. Since the accused products included the same ingredients as the patented composition, Kim simply assumed that they had the same effects on dough as did the patented composition.

However, with respect to a "consisting essentially of" claim, there is no infringement where the accused product contains additional, unclaimed ingredients that materially affect the basic and novel properties of the invention. See PPG Indus. v. Guardian Indus. Corp., 156 F.3d 1351, 1354 (Fed. Cir. 1998). Here, ConAgra's 7-Grain and Whole Wheat products contained additional ingredients beyond ascorbic and food acids, such as vital wheat glutten, ferrous sulfate, and dough strengthening enzymes. Based on testimony of its expert witness, ConAgra argued that the additional ingredients materially affected functionality. While Kim, who was qualified as an expert, offered conclusory testimony that the additional ingredients would not have materially affected the pertinent characteristics of the bread, Kim did not support this determination with any examinations or tests of the actual accused products. Under the circumstances of this case, we agree with the district court that Kim did not prove infringement because she presented no testimony based on the accused products themselves that supported a finding of infringement.

Recapturing Surrendered Subject Matter

In its cross-appeal, ConAgra argues that the asserted claims of the '355 patent are invalid because they improperly recapture material that Kim surrendered during prosecution of her original patent, and that the '355 patent is invalid as anticipated by, and obvious over, the prior art.

Kim had abandoned the original application and filed a CIP. Kim got the patent granted via phone interview, with narrower claims that Kim was not entirely satisfied with, so filed for reissue.

Kim tried to broaden the original claims by adding new claims that did not include the phosphate limitation and by broadening all the claims' ascorbic and food acid ranges.

The examiner initially rejected the reissue application as violating the rule against recapturing material that was surrendered or withdrawn during prosecution of the original patent. In so doing, the examiner did not state which of Kim's changes would violate the rule against recapture. After additional amendments not relevant to this case, the examiner allowed the reissued patent on October 26, 1999, as the '355 patent.

The reissue procedure allows a patentee to broaden the scope of an existing patent to include subject matter that had been erroneously excluded from that patent. 35 U.S.C. § 251 (2000). This procedure, however, is not without its limitations. For example, the "recapture rule prevents a patentee from regaining through reissue the subject matter that he surrendered in an effort to obtain allowance of the original claims." Pannu v. Storz Instruments, Inc., 258 F.3d 1366, 1370-71 (Fed. Cir. 2001) (internal quotation marks omitted). We have articulated a three-step process for applying the recapture rule:

The first step is to determine whether and in what aspect the reissue claims are broader than the patent claims. The second step is to determine whether the broader aspects of the reissued claim related to surrendered subject matter. Finally, the court must determine whether the reissued claims were materially narrowed in other respects to avoid the recapture rule.

Id. at 1371 (internal quotation marks omitted).

Here, the first and third steps are not at issue; that is, Kim concedes that reissued claims 5 and 10 are in fact broader than the original patented claims because they cover a non-phosphate potassium bromate replacer composition and a broader food acid range. Further, Kim concedes that neither reissued claim is narrower in any other material aspect. Thus, the only issue is whether the broader aspects of the reissued claims relate to "surrendered" subject matter. In this respect, we reject Kim's position that she should be treated differently from other patentees because she was pro se during some parts of the prosecution, and her argument that she was not responsible for the original amendment made with her acquiescence by the examiner.

The challenger of the reissued patent, here ConAgra, must establish surrender of recaptured subject matter by clear and convincing evidence. See Superior Fireplace Co. v. Majestic Prods. Co., 270 F.3d 1358, 1367 (Fed. Cir. 2001). A patentee can surrender subject matter either through arguments or amendments made during the prosecution of the original patent. Hester Indus., Inc. v. Stein, Inc., 142 F.3d 1472, 1480-81 (Fed. Cir. 1998). Whether surrender of recaptured subject matter has occurred is a question of law, which we review de novo. See N. American Container, Inc. v. Plastipak Packaging, Inc., 415 F.3d 1335, 1349 (Fed. Cir. 2005).

The district court here suggested that the patentee's subjective intent should be evaluated in determining whether the patentee surrendered subject matter. Some of our recapture decisions explain that "[e]rror under the reissue statute does not include a deliberate decision to surrender specific subject matter in order to overcome prior art," Mentor Corp. v. Coloplast, Inc., 998 F.2d 992, 996 (Fed. Cir. 1993) (emphasis added), and that the prerequisite error for a reissue can exist if "there is no evidence that the [applicant] intentionally omitted or abandoned the claimed subject matter." Ball Corp., 729 F.2d at 1435-36 (emphasis added). But these cases do not suggest that the patentee's subjective intent is pertinent to the question of surrender. These decisions simply distinguish between a patentee's inadvertent "error" (for which the reissue statute provides a remedy), and a patentee's "surrender" (for which the recapture rule prevents a reissue). ¹⁰

¹⁰ "If a patentee tries to recapture what he or she previously surrendered in order to obtain allowance of original patent claims, that deliberate withdrawal or amendment . . . cannot be said to involve the inadvertence or mistake contemplated by 35 U.S.C. § 251, and is not an error of the kind which will justify the granting of a reissue patent which includes the matter withdrawn." Mentor Corp., 998 F.2d at 995 (internal quotation marks omitted).

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. This is because the recapture rule is aimed at ensuring that the public can rely on a patentee's admission during prosecution of an original patent. "It is precisely because the patentee amended his claims to overcome prior art that a member of the public is entitled to occupy the space abandoned by the patent applicant. . . . [T]he reissue statute cannot be construed in such a way that competitors, properly relying on prosecution history, become patent infringers when they do so." Mentor Corp., 998 F.2d at 996; see also Vectra Fitness, Inc. v. TNWK Corp.,162 F.3d 1379, 1384 (Fed. Cir. 1998) ("[T]he 'recapture rule' prevents a patentee from regaining through reissue subject matter surrendered during prosecution, thus ensuring the ability of the public to rely on a patent's public record.") (emphasis added).¹¹ Thus, if 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.

¹¹ "Deliberately canceling or amending a claim in an effort to overcome a reference strongly suggests that the applicant admits that the scope of the claim before the cancellation or amendment is unpatentable, but it is not dispositive because other evidence in the prosecution history may indicate the contrary." In re Clement, 131 F.3d 1464, 1469 (Fed. Cir. 1997).

ConAgra was shot down on all its arguments, both for inclusion of phosphate, and the stated ranges in the claims.

ConAgra argues that the addition of phosphate was a surrender of non-phosphate potassium bromate replacer claims, which Kim later recaptured in the reissued patent... Kim overcame the obviousness rejection by changing the transition phrase from "comprising" to "consisting essentially of" and by changing her method claims to composition claims. While the phosphate limitation was added at the same time, the prosecution history does not indicate that Kim added that limitation in particular in order to overcome the obviousness rejection. Significantly, the examiner had previously rejected claims of the original application that included phosphate and noted that the phosphate salt limitation there was not "patentably significant." J.A. at 2735. Thus, the prosecution history refutes the argument that phosphate was added by Kim to overcome a rejection.

Likewise, the claimed range for food acids wasn't changed to overcome a prior art rejection.

Invalidity

ConAgra had its expert witness argue invalidity, but the expert admitted that he relied on a food chemistry book in one instance, not his own experimentation, and the jury was not impressed. Nor were they impressed on anticipation related to the claimed food acid ranges, where ConAgra would have liked to confuse ppm, parts per million, with percentages, in a prior art reference. ConAgra had an expert witness that didn't rise to the occasion.

So, Kim's patent is valid, but ConAgra didn't infringe it.