The Court of Appeals for the Federal Circuit has again heard from the parties in the now famous case between Festo Corp. and Shoketsu. In the latest round of Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 344 F.3d 1359, 2003 U.S. App. LEXIS 19867, Appeal No. 95-1066 (Fed. Cir. 2003) (en banc), on remand from the Supreme Court, 535 U.S. 722 (2002) ("Festo VIII"), the Federal Circuit has again attempted to apply the doctrine of equivalents.

 

Briefly, and by way of summary, the Federal Circuit had held (in Festo VII) that an amendment that narrows the scope of a claim for any reason related to the statutory requirements for a patent will give rise to prosecution history estoppel with respect to the amended claim element, and furthermore that when a claim amendment creates prosecution history estoppel, no range of equivalents is available for the amended claim element. Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., No. 95-1066, 234 F.3d 5J8 (Fed. Cir. Nov. 29, 2000) (en banc) (Festo VII). While so holding, the Federal Circuit acknowledged that its decision would often limit patent owners to a literal infringement analysis. It sought the certainty that "the patentee and the public can look to the prosecution history, a public record, to determine if any prosecution history estoppel arises as to any claim element." 234 F.3d at 576.

 

The U.S. Supreme Court, however, modified this absolute bar and created a "rebuttable presumption" which starts with the premise that when a patentee has chosen to narrow a claim, courts may presume that the amended text was composed with awareness of the bar, and that the territory surrendered is not an equivalent of the territory claimed. The Court carved out an exception, however, allowing the patentee to overcome the presumed bar against a claim of equivalence. This is the "rebuttable" part of the presumption against a claim of equivalence: the patentee may overcome the bar against a claim of equivalence where he can show that, at the time of the claim amendment, one skilled in the art could not reasonably be expected to have drafted a claim that would have literally encompassed the alleged equivalent. See, Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 62 USPQ2d 1705, 2002 WL 1050479 (2002) (Festo VIII).

 

Essentially, three tests were described by the Court, any one of which, if met, would be a basis for rebutting the presumption against infringement under the doctrine of equivalents. The three tests are: (1) the "Foreseeability" criterion for rebuttal; (2) the "Tangential Relation" criterion for rebuttal; and (3) the "Other Reason" criterion for rebuttal.

 

The first test requires a patentee to show that an alleged equivalent would have been "unforeseeable at the time of the amendment and thus beyond a fair interpretation of what was surrendered." Usually, if the alleged equivalent represents later-developed technology, or technology that was not known in the relevant art, then it would not have been foreseeable. In contrast, old technology, although not always foreseeable, would more likely have been foreseeable. A district court may hear expert testimony and consider other extrinsic evidence relating to the relevant factual inquiries.

 

The second test requires a patentee to demonstrate that "the rationale underlying the narrowing amendment [bore] no more than a tangential relation to the equivalent in question." The "tangential" criterion focuses on the patentee's objectively apparent reason for the narrowing amendment. That reason should be discernible from the prosecution history record, if the public notice function of a patent and its prosecution history is to have significance. Thus, the court should determine this criterion from the prosecution history record without the introduction of additional evidence except, when necessary, testimony from those skilled in the art as to the interpretation of that record may be heard. It remains to be seen whether a patentee will have to overcome an adverse inference if the reason for the amendment is not discernible from the PTO record.

 

The third test requires a patentee to establish "some other reason suggesting that the patentee could not reasonably be expected to have described the insubstantial substitute in question." When at all possible, determination of the third rebuttal criterion should also be limited to the prosecution history record. Again, there is an open question regarding arguments available to a patentee when the reason for the amendment is not discernible from the PTO record.

 

Moreover, the Supreme Court dismissed the "absolute bar" and replaced it with a rebuttable bar, which applies in those cases where, as the Court stated it, "[t]he equivalent may have been unforeseeable at the time of the application; the rationale underlying the amendment may bear no more than a tangential relation to the equivalent in question; or there may be some other reason suggesting that the patentee could not reasonably be expected to have described the insubstantial substitute in question. In those cases the patentee can overcome the presumption that prosecution history estoppel bars a finding of equivalence." Festo, 535 U.S. at 740-741.

 

 

On remand from the Supreme Court in Festo VIII, the Federal Circuit decided Festo IX, namely Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 344 F.3d 1359, 2003 U.S. App. LEXIS 19867, Appeal No. 95-1066 (Fed. Cir. 2003) (en banc), on remand from the Supreme Court, 535 U.S. 722 (2002) (Festo VIII). Thirteen judges decided the case, the en banc bench comprising the twelve active judges plus Senior Judge Plager. Eleven judges joined the opinion, Judge Rader filed a concurring opinion, and Judge Newman, joined by C.J. Mayer, concurred in part and dissented in part.

 

The Federal Circuit characterized the one issue in front of them on remand as whether Festo could rebut the presumption that the filing of narrowing amendments for the two patents in suit surrendered all subject matter between the original claim limitations and the amended claim limitations. The Federal Circuit held that Festo could not overcome that presumption by demonstrating that the rationale underlying the narrowing amendments bore no more than a tangential relation to the accused equivalents or by demonstrating that there was "some other reason" such that the patentee could not reasonably have been expected to have described the accused equivalents. The Federal Circuit did, however, remand to the district court to determine whether Festo could rebut the presumption of surrender by establishing that the equivalents in question would have been unforeseeable to one of ordinary skill in the art at the time of the amendments. Thus, the story continues.

In its simplest form, the issue now decided by the Federal Circuit on remand from the Supreme Court is actually a court-created exception to an exception to an exception of established statutory law. That is to say, the entire idea of infringement under the (court-created) doctrine of equivalents is an exception to the statutory definition of infringement under 35 U.S.C. § 271. The exception to infringement under the doctrine of equivalents is the (court-created) counter posing doctrine of prosecution history estoppel. The exception to the application of prosecution history estoppel to preclude infringement under the doctrine of equivalents exists where the patentee demonstrates that it did not surrender the particular equivalent in question according to one of the three criteria described above.

 

Thus, the question for a plaintiff patentee is whether it can establish the exception (no surrender) to an exception (prosecution history estoppel) to an exception (doctrine of equivalents) to a conclusion of no literal infringement. This point was explicitly recognized in Judge Rader's concurring opinion in which he stated, "[f]or a third (or perhaps a fourth) time, this court revisits some exceptions to an exception to an exception to the standard rule of infringement." Judge Rader also expressed the further uncertainty being created: "[w]ith exception added to exception, and presumptions rebutted by still newer presumptions, a practitioner can scarcely predict the scope of claims years in the future, when they are likely to be enforced, let alone the scope of claims drafted a few years ago when amendments did not potentially forfeit claim scope. In other words, the pace of the creation of new rules is itself disrupting the fundamental principle of certainty in the scope of patent claims." Patents only serve their role in promoting the progress of the useful arts where their scope can be relied upon by the public. Whether the "new" rules pertaining to infringement under the doctrine of equivalents further this objective remains to be seen.

In her dissent, Judge Newman (joined by Chief Judge Mayer) noted: "[s]everal amici curiae pointed out the incongruity whereby equivalency in fact follows from known (foreseeable) interchangeability, . . . yet the patentee must now prove unforeseeability in order to gain access to the doctrine of equivalents." Festo, 344 F.3d at 1383 n.3. This raises an interesting twist between competitors embroiled in an infringement argument.

Under the "old" rule, a plaintiff patentee would argue that the defendant infringed under the doctrine of equivalents something along these lines: "You may not literally infringe, but you infringe under the doctrine of equivalents because you merely substituted aluminum for copper and everyone knows that these two elements are interchangeable for the purposes of the claimed device. What you're doing is really just the same thing that we claimed." The defendant would counter, "we deliberately used aluminum because you narrowed your claim from copper and silver to just copper. You only disclosed copper and silver in your specification and aluminum is clearly something you never even thought about using; it can't be considered an equivalent because it is so different from what you disclosed and claimed."

 

Under the "new" rule, the roles are completely reversed. The plaintiff patentee says, "What you are doing is something we never could have thought of doing. We never had any idea someone could substitute aluminum for copper for this purpose. Therefore, you infringe under the doctrine of equivalents." And the defendant says, "No. Your invention as disclosed clearly envisioned the use of aluminum because everyone knows silver, copper, and aluminum are similar enough for purposes of your claimed device. Therefore aluminum was foreseeable and should have been claimed. Therefore we don't infringe under the doctrine of equivalents."

 

The above example, albeit somewhat exaggerated, illustrates the incentives provided by an identification of foreseeable equivalents to a competitor seeking to design around a patented invention. Knowing that foreseeable embodiments are not protected, the competitor purposefully adopts a foreseeable variation of an amended claim limitation to avoid infringement under the doctrine of equivalents (no, that's not a typo). A truly innovative variation, however, risks characterization as an unforeseeable equivalent for which protection exists. Thus, the "unforeseeable equivalents" criterion of the Supreme Court may actually encourage minor changes by competitors rather than truly innovative changes.

 

All of this makes for at least an interesting situation among patent owners and the use of the doctrine of equivalents. As stated by the Supreme Court in Graver Tank & Mfg. Co. v. Linde Air Products, 339 U.S. 605, 85 USPQ 328 (1950), the purpose of the doctrine of equivalents is to prevent the "unscrupulous copyist" from abusing the patent system. Has the Supreme Court now set the groundwork for making it easier for the unscrupulous copyist to make victims out of patent owners who were without the benefit of the current law at the time they prosecuted their claims? Stay tuned.