Guest Post by Scott McKeown, Greg Gardella, and Lisa M. Mandrusiak all of OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, L.L.P.
The Court of Appeals for the Federal Circuit is currently considering en banc the panel decision in Marine Polymer Technologies, Inc. v. Hemcon, Inc. The panel decision can be interpreted as suggesting that intervening rights can arise from an argument made during a post grant patent proceeding, such as a patent reexamination proceeding, even if the patent owner is merely urging a claim interpretation that is consistent with the manner in which the term would have been understood at the time the underlying patent application was filed. In cases where the post grant record simply clarifies the way in which a skilled artisan would have understood a claim term at the time of filing, or reiterates the positions of the previous intrinsic record, the scope of the claims cannot properly be said to have been altered during the subsequent proceeding.
Post grant PTO patent proceedings often focus on the meaning of different aspects of originally issued claim language than were considered during the earlier application prosecution. Therefore, much of the argument made by the patent owner during the subsequent PTO proceeding is directed to new issues not previously considered by the PTO. It is to be expected that re-opening the intrinsic record via post grant file histories will often include substantively new discussion of various claim terms.
For example, during post grant proceedings patent claims are accorded the broadest reasonable interpretation ("BRI"). Determining the BRI requires a different analysis than carried out in a district court during claim construction, and notably, there is no requirement that the PTO consider the earlier prosecution record in ascertaining the BRI and meaning of an originally issued patent claim. This often places patent owners in the position of having to re-argue distinctions which were implicitly or explicitly accepted by the previous patent examiner. When the PTO requires amendment of a claim in post grant proceedings the amendment may in fact be a simple restatement of previously agreed upon claim scope, which should not give rise to intervening rights.
The rule adopted by the Court should be flexible so as to accommodate the foregoing situations and permit intervening rights only in the appropriate circumstances. The application of argument-based intervening rights should be limited to situations in which the patent owner clearly and unambiguously revises the issued claim scope by urging that a limitation has a meaning that is plainly at odds with the interpretation a court would have given the originally issued claim language.
The Legal Standard Should Recognize and Accommodate the Practical Reality that Not Every Argument Alters Claim Scope in the Manner Contemplated by the Statutory Provisions Governing Intervening Rights
Post grant proceedings typically involve claim rejections based on prior art that was not fully considered or applied by the examiner during the ex parte prosecution of the underlying patent application. Such prior art references are often distinguished based on facets of the claim language not previously addressed in the original prosecution of the underlying patent application.
For instance, a claim directed to the combination of A, B and C may have been deemed allowable because no reference taught that B could be used in conjunction with C. A reexamination may be initiated based on prior art that teaches the combination of B and C. The patent owner might successfully argue during reexamination that the new prior art reference does not teach A as that term is properly understood. Virtually any explanation and argument with respect to element A could conceivably give rise to intervening rights if one were to broadly apply the principles set forth in the majority's holding in Marine Polymer.
However, the statutory intervening rights provisions (35 U.S.C. §§ 252 and 307) were intended to prevent liability from accruing during the period prior to the rectification of a validity defect through reexamination. Congress explicitly stated that its objective in passing 35 U.S.C. § 307(b) was to ensure that a party is not held liable for infringement during the period between the issuance of an invalid patent and the time when that patent is made valid via amendments during reexamination:
Thus, a person practicing a patented invention would not be considered an infringer for the period between issuance of an invalid patent and its conversion through reexamination to a valid patent
H.R. Rep. No. 96-1307(I), at 7 (1980), reprinted in 1980 U.S.C.C.A.N. 6460, 6467.
A finding of intervening rights may be inappropriate where a post grant proceeding does not clearly involve rectification of a validity defect. For instance, if a patent owner sets forth on the record a well-established and undisputed definition of a technical term in order to distinguish newly cited prior art, the claim may not have been narrowed at all in the view of a skilled artisan. Rather, the skilled artisan may have always understood the claim term in a manner consistent with the definition that was placed on the record during the post grant proceeding.
Post Grant Patent Practice Sometimes Requires Patent Holders to Restate Previously Understood Claim Interpretations, Which Should Not Give Rise to Intervening Rights
The Marine Polymer majority opinion expressed the concern that an intervening rights doctrine which was limited to express claim amendment "would allow patentees to abuse the reexamination process by changing claims through argument rather than changing the language of the claims to preserve otherwise invalid claims and…avoid creating intervening rights as to those claims." Slip Op. at 11. This concern, which at its core is a concern that the PTO will overlook its duty to give the claims the BRI, appears to have given rise to the majority opinion which suggests that intervening rights can arise from any argument made during a post grant patent proceeding. That holding should be clarified in a manner that is consistent with the realities of post grant PTO patent practice.
During post grant proceedings, patent claims are accorded the BRI. In re Suitco Surface, Inc., 603 F.3d 1255, 1259 (Fed. Cir. 2010). This standard also applies to, and is borrowed from, ex parte patent prosecution, and is notably distinct from the analysis done in the district court which considers the earlier prosecution (intrinsic) record for guidance as to claim meaning. Phillips v. AWH Corp., 415 F.3d 1303, 1317 (Fed. Cir. 2005) (en banc); In re American Academy of Science Tech Center, 367 F.3d 1359, 1369 (Fed. Cir. 2004) (The PTO uses a different standard for construing claims than that used by district courts; during examination the PTO must give claims their BRI in light of the specification).
Since there is no requirement that the PTO consider the earlier prosecution record in ascertaining the meaning of an originally issued patent claim, patent owners are sometimes placed in the unfortunate position of having to "re-bargain" for understandings and distinctions accepted by previous, and very likely different, patent examiners. While the PTO in the vast majority of cases requires amendment of claims in post grant proceedings, such changes may in fact be a restatement of the previous examiner's (correct) interpretation of the claim term.
There should be few situations where a patent owner is permitted in a reexamination to implicitly or explicitly define a claim term (in order to distinguish the prior art) via a post grant proceeding in a manner that revises the scope of the claim term relative to the way the term would have been understood by a skilled artisan at the time of the initial application filing. Generally, the PTO will require the claims to be amended where the patent owner is urging a claim interpretation that is narrower than the BRI, even where such narrower meaning coincides with the proper Phillips interpretation. The application of argument-based intervening rights should be limited to those rare instances in which the PTO allows a new disclaimer to avoid art in a post grant proceeding, as opposed to the more common explanation or restatement of claim scope found in the vast majority of post grant proceedings.
Argument Merely Explaining How a Skilled Artisan Would Have Understood the Term at the Time of Filing Should Not Give Rise to Intervening Rights
The majority's decision in Marine Polymer could be broadly interpreted as suggesting that any argument estoppel substantively changes the meaning of the claims and gives rise to intervening rights, including clarifying argument. However, as noted above, the PTO is expected to give the claims the BRI, which in turn puts the onus on the patent owner to explain why the claim terms would not have been interpreted so broadly by a person skilled in the art.
These patent owner explanations do not necessarily change the claim scope. In fact, many such arguments merely explain and clarify the manner in which the claim terms were used at the time of filing, and the Court has previously held that even express claim amendments to clarify the text of a claim or make it more definite without affecting scope do not give rise to intervening rights. Kaufman Co. v. Lantech, Inc., 807 F.2d 970, 977 (Fed. Cir. 1986). Where the patent owner's arguments simply explain the manner in which a skilled artisan would have understood the relevant claim terms at the time of filing, the claim terms cannot be considered to have changed in scope.
The Public Interest Is Best Served By Limiting Intervening Rights to Clear and Unambiguous Disavowal of Claim Scope
Argument should give rise to intervening rights only where it clearly and unmistakably alters the scope of the claim given the manner in which the claim language would have been understood at the time of filing. "[D]isclaimers based on disavowing actions or statements made during prosecution…must be both clear and unmistakable." Sorensen v. Int'l Trade Comm'n, 427 F.3d 1375, 1378-79 (Fed. Cir. 2005) (citing Omega Eng'g Inc. v. Raytek Corp., 334 F.3d 1314, 1326 (Fed. Cir. 2003)). A finding of "disclaimer" must be clear, deliberate, and so unmistakable as to be supported by unambiguous evidence. See, e.g., N. Telecom Ltd. v. Samsung Elecs. Co. Ltd., 215 F.3d 1281, 1294-95 (Fed. Cir. 2000). This same principle should be applied to determine whether a patentee has made a disclaimer through argument in reexamination.
The public interest is best served by a flexible approach which balances the settled expectations of patent owners against the justifiable reliance of the public on the original file history. Patent owners have a proper and settled expectation that their patent rights will be fully enforceable if the PTO confirms the claims on the basis that the prior art would not have met the original claim language, as that language would have been understood by a skilled artisan at the time of filing. The public likewise has a proper and settled expectation that intervening rights may be available if the original claim language, as that language would have been understood by a skilled artisan at the time of filing, was unduly broad and thus embraced prior art. The common thread between both sets of expectations is the meaning of the issued claim language as it would have been understood by one skilled in the art at the time of filing. If that claim scope is substantively modified, intervening rights should be available.
 The views expressed in this article are those of the authors and not necessarily those of the firm.
 The intervening right statute currently applies to both patent reissue (35 U.S.C. § 252) and reexamination (35 U.S.C § 307) and going forward will apply to additional proceedings of the Leahy-Smith America Invents Act.
 In the case at bar the Examiner appears to have allowed the doctrine of claim differentiation to trump the required BRI analysis.