Chief Judge Leonard P. Stark’s recent claim construction opinion in E.g., Kraft Foods Brands LLC v. TC Heartland, LLC d/b/a/ Heartland Food Products Group, et al., C.A. No. 14-028-LPS (D. Del. Mar. 7, 2016) includes consideration of the an indefiniteness dispute which the Court ultimately concluded could not be resolved on the present record. The dispute centered on the meaning of “otherwise identical” in the term “to provide the concentrate with at least about 5 times more acid than an otherwise identical non-buffered concentrate having the same pH.” Defendant argued the term was indefinite, while Plaintiff argued the term should be given its plain and ordinary meaning. See id. at 9-11. The Court concluded that Defendant had not met “the heavy burden it has taken on in seeking to invalidate the claims” as indefinite, but it was also not clear which alternative constructions presented by the parties were correct. Id. at 13. Accordingly, the Court required additional input from the parties to resolve the issue, and indicated that it may be helpful to hear “hear directly from experts as to how a POSA would” understand the terms at issue. Id. at 13. The Court indicated it would direct the parties to propose what additional proceedings that would allow for resolution. Id. at 14.
In the same opinion, the Court also concluded that a preamble was limiting, as the prosecution history demonstrated that the patentee “had relied on the features recited in the preamble to overcome an obviousness rejection.” Id. at 22.