"A" in a Patent Claim Means "One or More" Says Federal Circuit Yet Again

Two familiar aspects of claim-construction analysis strongly support the plural-allowing meaning here. First, “at least in an open-ended ‘comprising’ claim,” like claim 1 of the ’439 patent, “use of ‘a’ or ‘an’ before a noun naming an object” requires that the phrase be construed to mean “‘one or more’ unless the context sufficiently indicates otherwise.” Lite-Netics, 60 F.4th at 1345; see Salazar, 64 F.4th at 1315; Convolve, Inc. v. Compaq Computer Corp., 812 F.3d 1313, 1321 (Fed. Cir. 2016); Baldwin, 512 F.3d at 1342–43. 

The court has called this the “general rule,” adding that an exception “only arises where the language of the claims themselves, the specification, or the prosecution history necessitate a departure from the rule.” Baldwin, 512 F.3d at 1343. Second, the specification here states: “[F]or the purposes of the present disclosure, the term ‘a’ or ‘an’ entity refers to one or more of that entity. As such, the terms ‘a’ or ‘an’, ‘one or more’ and ‘at least one’ can be used interchangeably herein.” ’439 patent, col. 18, lines 27–30. That definition reinforces, rather than negates, the applicability here of the “one or more” general rule concerning “a” or “an.”

ABS GLOBAL, INC. v. CYTONOME/ST, LLC

https://cafc.uscourts.gov/opinions-orders/22-1761.OPINION.10-19-2023_2208330.pdf