A Western District of Wisconsin judge has rejected an attempt by the Wisconsin Alumni Research Foundation (WARF), the non-profit, patent management arm of the University of Wisconsin, to revive its litigation against Apple. After the Federal Circuit overturned a $506M judgment against the company in 2018, holding that the defendant had not directly infringed under the proper application of a key claim term, WARF had asked the district court to let it pursue claims of infringement under the doctrine of equivalents. However, on May 10, District Judge William M. Conley declined to reopen the case, holding that WARF had waived that issue—having previously agreed not to assert a doctrine of equivalents theory in an attempt to resolve an evidentiary dispute.

WARF filed its first suit against Apple—the one with the later-reversed-verdict—in January 2014, targeting Apple’s A7 and A8 mobile processors over their incorporation of a Load-Store Dependency (LSD) Predictor (3:14-cv-00062). In September 2015, WARF brought a second suit against the company (3:15-cv-00621) targeting the A9 and A9X processors, subsequently adding the A10 via amended complaint—all chips that incorporate the same accused technology as the first case. Soon after filing, that second case was stayed as to all matters except discovery pending the outcome of the first lawsuit, including any appeals. Asserted in both cases was a single patent (5,781,752) that generally relates to preventing microprocessors capable of performing commands out of their sequential order from committing errors by tracking commands that have caused problems when taken out of order in the past.

In the first case, WARF asserted that in addition to its claims of literal infringement, it would pursue an alternative theory under the doctrine of equivalents for any claim element Apple challenged as not being met literally, including such a theory in its expert reports. However, as the case approached trial, Apple sought to introduce a soon-to-issue patent application (13/464,647) covering its own LSD Predictor as evidence of noninfringement on that basis. WARF then filed a motion in limine to exclude any evidence, testimony, or argument regarding the application, with Apple opposing on the basis that the LSD Predictor being separately found patentable was relevant to WARF’s DOE infringement theory. As would later become relevant, WARF stated during supplemental briefing on that issue that if evidence on Apple’s patent (which had at that point issued) were excluded, it would “drop doctrine of equivalents and make no doctrine of equivalents argument whatsoever at trial,” assuming the court were to decide that Apple had “laid a proper foundation” for its presentation to the jury. Apple offered in response that it would not offer the application, or the patent that had by that point issued from it (9,128,725), “if the doctrine of equivalents is not in issue”.

While Judge Conley denied the motion in limine and ruled that the patent would be admissible, he also acknowledged the parties’ “apparent compromise” on the issue, ordering that “[b]y agreement of the parties . . . neither side may introduce evidence or argument regarding the ‘647 application, prosecution or issuance during the liability phase of trial”. WARF then reaffirmed the parties’ agreement, at Apple’s request, in an email to its counsel: “WARF will not raise or mention doctrine of equivalents, and Apple will not raise or mention the ‘647 application of the ‘725 patent in the liability phase”.

The case proceeded to a bifurcated trial in October 2015, with the first phase culminating in a verdict that Apple had infringed all six asserted claims from the ‘752 patent and that none of the claims were invalid. Three days later, Judge Conley granted judgment as a matter of law of no willful infringement for Apple, finding that Apple’s obviousness defense was objectively reasonable as presented at trial. The case saw a second trial shortly afterward, with the jury finding that Apple was vicariously liable for infringement through Samsung’s manufacture of certain Apple components and awarding $234M in damages against Apple.

The parties then proceeded to file a variety of post-trial motions, which Judge Conley decided in a single order in June 2017. Among other issues addressed, the court denied Apple’s motion for renewed judgment as a matter of law or for a new trial, holding that “the evidence easily supports the jury’s findings of infringement on all three disputed elements of the asserted claims” and that the evidence supported the findings of no invalidity and of vicarious liability. However, Judge Conley also denied WARF’s motion to alter and amend the judgment of no willful infringement, holding that WARF had not made a sufficient showing of willfulness even under the more relaxed, subjective standard for awarding enhanced damages established by the Supreme Court’s 2016 decision in Halo Electronics v. Pulse Electronics. The following month, the court entered a final judgment that imposed a total of $506M in damages, including the jury’s damages award plus supplemental damages, ongoing royalties, pre- and post-judgment interest, and costs.

Ruling on appeal in September 2018, the Federal Circuit focused on Apple’s argument that the processors at issue do not satisfy a key limitation for the “predictor” described by the ‘752 patent: specifically, the “particular” limitation, where the predictor “produce[s] a prediction associated with [a] particular [load] instruction”. Here, the Federal Circuit noted that the district court had accepted Apple’s argument, at trial, that the term should be given its plain and ordinary meaning. Turning to the term itself, the Federal Circuit then ruled that “the plain meaning of ‘particular,’ as understood by a person of ordinary skill in the art after reading the ‘752 patent, requires the prediction to be associated with a single load instruction”, further clarifying that “[a] prediction that is associated with more than one load instruction does not meet this limitation”. Applying that definition, the Federal held in relevant part “that no reasonable juror could have found literal infringement in this case”, as the claimed “load tags”—“each generated by hashing information about a load instruction”, and corresponding to certain predictions—“can . . . be associated with a group of load instructions”. The court also acknowledged the resolution of the doctrine of equivalents issue, stating that “WARF abandoned its theory of infringement under the doctrine of equivalents before trial, and has proceeded only on a theory of literal infringement”.

The Federal Circuit concluded by reversing the judgment of infringement without remand for further proceedings on infringement. WARF then asked the court to remand with respect to infringement under the doctrine of equivalents in its petition for en banc rehearing, but the court denied that petition altogether. Once the Federal Circuit issued its mandate in January 2019, WARF again attempted to revive the litigation by moving to have the district court reopen the case, arguing that the mandate only applied to literal infringement and that it had not waived its doctrine of equivalents arguments under Federal Circuit precedent.

Judge Conley disagreed in a May 10, 2022 order entered in both Apple suits, taking particular issue with WARF’s reliance on the Federal Circuit’s 1998 decision in Exxon Chemical Patents v. Lubrizol. While Judge Conley agreed that “Exxon allows an opening for a claim of infringement under the doctrine of equivalents’ upon remand from an appeal reversing a finding of literal infringement”, he held that the decision does not require that result. Judge Conley also distinguished the case on procedural grounds. While the plaintiff in Exxon had its doctrine of equivalents claim mooted by a claim construction order that was reversed on appeal, Judge Conley observed that here, it was WARF that decided not to pursue such a claim—a decision that did not result from any decision later overturned. Regardless, Judge Conley noted that since the Federal Circuit had also affirmed that WARF had abandoned its doctrine of equivalents theory, that was “now the law of the case”.

Even if Exxon “somehow allowed for the possibility of a do-over”, Judge Conley continued, the Federal Circuit’s interpretation of the plain and ordinary meaning of “particular”—as requiring an LSD Predictor “to be associated with a single load instruction”—“precludes as a matter of law of the case WARF’s argument now that this limitation allows for an equivalence infringement based on the prediction being associated with a group of load instructions, something it is undisputed each load tag in the accused LSD Predictor depends upon”.

Additionally, Judge Conley rejected WARF’s argument that it should be able to argue infringement under the doctrine of equivalents in the second suit targeting the newer A9, A9X, and A10 processors. Here, the court agreed with Apple that this was precluded under the Federal Circuit’s 2009 Nystrom v. Trex decision. In Nystrom, the appellate court—“after having already affirmed a non-infringement judgment and the district court’s finding of waiver of the doctrine of equivalents claim—determined that the assertion of patent infringement in a new lawsuit against second-generation products released during the pendency of the first suite was barred by preclusion principals”, as the newer products were unchanged with respect to the claim limitations at issue.

The court found that the situation was effectively identical in this case:

Here, too, the Federal Circuit’s holding in WARF I applies with equal force to the accused products (namely iPhones and iPads with chips still using the same LSD Predictor found not to have infringed the ‘752 patent in WARF I). Similarly, plaintiff WARF not only waived any doctrine of equivalents claim in WARF I, but the Federal Circuit’s opinion precludes any arguable claim to equivalence, both as explained already. Therefore, WARF is barred from pursuing such a claim not only in WARF I but in this new case, procedurally and on the merits. Finally, as detailed above, WARF concedes—or, at minimum, it is now estopped from disputing—the LSD Predictor in the A9, A9X and A10 chips that are the subject of WARF II are the same as the chips at issue in WARF I, at least for purposes of plaintiff’s infringement claims under the ‘752 patent.

Judge Conley found WARF’s “response to this seemingly obvious conclusion” to be “scattershot at best”. For instance, he rejected its argument that claim preclusion could not apply because there had not yet been a judgment consistent with the Federal Circuit’s opinion—countering that the court’s newfound issuance of an amended judgment consistent with its May 10 opinion essentially mooted that position. As for its assertion that “claim preclusion cannot apply because at least some of the products at issue in WARF II were not on the market at the time WARF filed its first lawsuit”, Judge Conley noted further similarities between this case and Exxon, in which the Federal Circuit also found that the plaintiff was barred from pursuing a doctrine of equivalents theory due to waiver as to a “materially similar, earlier generation of the same products despite later generations being produced during and after the course of the first litigation”. Finally, as to WARF’s insistence that claim preclusion could not apply because the district court had not actually decided the doctrine of equivalents issue, Judge Conley held that “WARF no longer has any viable doctrine of equivalence infringement claim on the merits” as a result of the Federal Circuit’s interpretation of the claim term “particular”.

Judge Conley’s ruling follows another recent setback for a university plaintiff. In February, a Federal Circuit majority overturned a California jury’s finding of infringement for the California Institute of Technology against Apple and Broadcom as to one of the three tried Wi-Fi networking patents and remanded for a new trial, ruling that the lower court erred by failing to instruct the jury on the proper construction of a key claim term. The majority also unwound the jury’s $1.1B damages award, concluding that the district court was wrong to allow a “legally erroneous” two-tiered damages theory that applied separate hypothetical negotiations to the sale of the same chips.

For more on that decision, see “Federal Circuit Trims Infringement Verdict Against Apple and Broadcom and Nixes $1.1B Damages Award in Caltech Wi-Fi Suit” (February 2022).