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That’s So Metal: Narrow Limitation Doesn’t Contradict Broader One

The US Court of Appeals for the Federal Circuit reversed a district court’s indefiniteness determination, finding that two claim limitations – one broad and one narrow – were not contradictory since it was possible to meet the requirements of both. Maxell, Ltd. v. Amperex Technology Limited, Case No. 23-1194 (Fed. Cir. Mar. 6, 2024) (Prost, Taranto, Chen, JJ.)

Maxell owns a patent directed to a rechargeable lithium-ion battery. Maxell filed suit against Amperex alleging infringement. Following claim construction proceedings, the district court found the claims to be indefinite based on two limitations in the independent claim that recited the variable M1. The relevant claim limitations read:

1- wherein M1 represents at least one transition metal element selected from Co, Ni and Mn, [. . .]

2- wherein the content of Co in the transition metal M1 of the formulae (1) and (2) is from 30% by mole to 100% by mole[.]

The district court found that these two limitations contradicted each other because limitation 1 recited Co (cobalt) as an optional transition metal selected from a Markush group for M1, whereas limitation 2 recited a minimum Co content of 30% in M1. The district court reasoned that the claims were indefinite because limitation 1 did not require the presence of cobalt, whereas limitation 2 did. In its claim construction order, the district court stated that simultaneous recitation that a claim element is both optional and required is a “contradiction on its face.” Maxell appealed.

The Federal Circuit found no contradiction between the two limitations, explaining that “[i]t is perfectly possible for a selected [M1] to satisfy both of these limitations.” The Court reasoned that in the context of Maxell’s patent, it was of no import that the two requirements (i.e., that M1 must comprise cobalt, nickel (Ni) or manganese (Mn), and that M1 must comprise at least 30% cobalt) were recited in separate clauses. It was enough that both limitations could be simultaneously satisfied. The Court further reasoned that the inclusion of two requirements in a claim did not create an otherwise nonexistent contradiction because the claim language must be read as a whole and not merely on a limitation-by-limitation basis. The Court also looked to the prosecution history to provide context for the ordering of the claim limitations at issue and explained that limitation 2 was added during prosecution to overcome a prior art reference that primarily used nickel as a transition metal.

The Federal Circuit explained that contrary to the district court’s characterization, the subject claim limitations did not grant options. Instead, they stated requirements that must be met to fall within the scope of the claimed invention. The Court noted that, rather than contradicting limitation 1, limitation 2 narrowed it. If limitation 2 had been recited in a dependent claim, there would be no contradiction, notwithstanding that proper construction of a dependent claim requires importation of all limitations from the claims from which it depends. The same conclusion applied when both limitations were [...]

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Console Yourself: Patent Owner Bears IPR Estoppel Burden

Addressing for the first time the standard and burden of proof for the “reasonably could have raised” requirement for inter partes review (IPR) estoppel to apply, the US Court of Appeals for the Federal Circuit concluded that a patent owner bears the burden of proving that an IPR petitioner is estopped from using invalidity grounds that a skilled searcher conducting a diligent search reasonably could have been expected to discover. Ironburg Inventions Ltd. v. Valve Corp., Case Nos. 21-2296; -2297; 22-1070 (Fed. Cir. Apr. 3, 2023) (Lourie, Stark, JJ.) (Clevenger, J., dissenting).

Ironburg sued Valve for infringing Ironburg’s video game controller patent. Valve responded by filing an IPR petition in 2016. The Patent Trial & Appeal Board partially instituted on three grounds but declined to institute on two other grounds (the Non-Instituted Grounds), as was permitted prior to the Supreme Court’s 2018 decision in SAS Institute Inc. v. Iancu. Valve did not seek remand pursuant to SAS, which would have allowed the Board to consider the Non-Instituted Grounds. In the district court litigation, Valve alleged invalidity based on the Non-Instituted Grounds and grounds Valve learned of from a third party’s IPR filed after Valve filed its IPR (the Non-Petitioned Grounds). Ironburg filed a motion asserting that Valve was estopped, pursuant to 35 U.S.C. § 315(e)(2), from asserting both the Non-Instituted Grounds and the Non-Petitioned Grounds. The district court granted Ironburg’s motion in full, removing all of Valve’s invalidity defenses. After trial, the jury returned a verdict finding that Valve willfully infringed the patent. Valve appealed.

35 U.S.C. § 315(e)(2) precludes an IPR petitioner from asserting invalidity during a district court proceeding based on “any ground that the petitioner raised or reasonably could have raised during that [IPR].” The Federal Circuit first addressed the legal standard needed to meet the “reasonably could have raised” requirement for IPR estoppel. The Court found that the “skilled searcher” standard used by several district courts is appropriate, as opposed to a higher “scorched earth” search standard. The “skilled searcher” standard is consistent with the § 315(e)(2) statutory requirement of discovering prior art references that “reasonably could have been raised.”

The Federal Circuit next addressed which party has the burden to prove what prior art references a skilled searcher reasonably would, or would not, have been expected to discover. The district court placed the burden on Valve, the party challenging the patent’s validity, and determined that Valve did not show how difficult it was to find the Non-Petitioned Grounds that Valve did not initially uncover. The Court noted that the third party that did find the Non-Petitioned Grounds may have used a “scorched earth” search, which would make its discovery of the Non-Petitioned Grounds irrelevant to estoppel. The Court concluded that the patent owner has the burden of proving what a skilled searcher reasonably would have found because the patent holder is looking to benefit from estoppel. The Court explained that this conclusion is consistent with the practice of placing the burden on the party asserting [...]

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Terms of Degree Not Always Indefinite

The US Court of Appeals for the Federal Circuit overturned a district court determination that the claim terms “resilient” and “pliable” were indefinite. The Federal Circuit found that the claims, while broad, were sufficiently definite in view of both intrinsic and extrinsic evidence. The Federal Circuit also upheld the district court’s findings of no induced infringement, finding zero evidence of predicate direct infringement of the properly construed method claims. Niazi Licensing Corp. v. St. Jude Medical S.C., Inc., Case No. 21-1864 (Fed. Cir. Apr. 11, 2022) (Taranto, Bryson, Stoll, JJ.) The Federal Circuit also affirmed entry of sanctions excluding portions of the plaintiff’s technical and damages expert reports for failing to disclose predicate facts during discovery and also affirmed exclusion of portions of plaintiff’s damages expert report as unreliable for being conclusory and legally insufficient.

In reaching its decision on indefiniteness, the Federal Circuit focused on the terms “resilient” and “pliable” as used in a claim directed to a double catheter structure. Citing the 2014 Supreme Court decision in Nautilus v. Biosig Instruments, the Federal Circuit explained that language has “inherent limitations,” and stated that a “delicate balance” must be struck to provide “clear notice of what is claimed” and avoid the “zone of uncertainty” relating to infringement. The Court noted that under Nautilus, claims must provide “objective boundaries,” but the Court distinguished the present case from those in which “subjective boundaries” created uncertainty and rendered the claim indefinite. The Court pointed to its 2005 decision in Datamize v. Plumtree Software as a “classic example” of subjectivity where the term “aesthetically pleasing” was deemed indefinite because the patent provided no way to provide “some standard for measuring the scope of the phrase.” The Court also noted that a patent’s claims, written description and prosecution history—along with any relevant extrinsic evidence—can provide or help identify the necessary objective boundaries for claim scope

The Federal Circuit concluded that there was sufficient support in the intrinsic evidence, both in the claims themselves and the written description, to allow a skilled artisan to determine the scope of the claims with reasonable certainty. The Court explained that the claim at issue recited “an outer, resilient catheter having shape memory” that “itself provides guidance on what this term means—the outer catheter must have ‘shape memory,’ and ‘sufficient stiffness.’” The Court also cited to “[n]umerous dependent claims [that] further inform the meaning of this term by providing exemplary resilient materials of which the outer catheter could be made. . . . The written description provides similar guidance . . . . Thus, a person of ordinary skill reading the claims and written description would know of exemplary materials that can be used to make a resilient outer catheter, i.e., one that has shape memory and stiffness such that it can return to its original shape.”

The Federal Circuit distinguished this case from Datamize, where the claim scope depended on the eye of each observer, finding it more akin to its 2017 decision in Sonix Technologies. In that [...]

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