"A" Question: To Mean Only One, Or One Or More?

• Published date: 07 June 2023
• Subject Matter: Intellectual Property, Real Estate and Construction, Patent, Construction & Planning
• Law Firm: Finnegan, Henderson, Farabow, Garrett & Dunner, LLP
• Author: Bowen Li, Adriana Burgy and Stacy Lewis

Choice of words can have a significant impact on conveying meaning. Patent drafting is no different. For example, the smallest word such as "a" can significantly change the scope of a construed claim. Patent practitioners must continue to ask, what do I mean by "a."

In a recent case Salazar v. AT&T Mobility LLC, 64 F.4th 1311 (Fed. Cir. 2023), the Federal Circuit discussed the meaning of "a" in the context of open-ended claims with the transitional phrase "comprising." In Salazar, the claim phrases at issue read:

1. A communications, command, control and sensing system for communicating with a plurality of external devices comprising:

a microprocessor for generating a plurality of control signals used to operate said system, said microprocessor creating a plurality of reprogrammable communication protocols ...

a memory device coupled to said microprocessor configured to store a plurality of parameter sets retrieved by said microprocessor so as to recreate a desired command code set ...

said microprocessor generating a communication protocol in response to said user selections ....

At issue was the construction of the articles "a" and "said" followed by the term "microprocessor." In previous cases, the Federal Circuit explained that the indefinite article "a" means "'one or more' in open-ended claims containing the transitional phrase 'comprising.'" Convolve, Inc. v. Compaq Computer Corp., 812 F.3d 1313, 1321 (Fed. Cir. 2016) (quoting KCJ Corp. v. Kinetic Concepts, Inc., 223 F.3d 1351, 1356 (Fed. Cir. 2000)). "An exception to the general rule that 'a' ... means more than one only arises where the language of the claims themselves, the specification, or the prosecution history necessitate a departure from the rule." Baldwin Graphic Sys., Inc. v. Siebert, Inc., 512 F.3d 1338, 1342-43 (Fed. Cir. 2008). "The subsequent use of [the] definite article[] ... 'said' in a claim to refer back to the same claim term does not change the general plural rule, but simply reinvokes that non-singular meaning." Id. at 1342.

In Salazar, the district court construed the claim terms at issue to mean "one or more microprocessors, at least one of which is configured to perform the [recited] generating, creating, retrieving, and generating functions." Salazar, 64 F.4th at 1314. On appeal, Mr. Salazar held a view that a correct claim construction would encompass one microprocessor capable of performing one claimed function and another microprocessor capable of performing a...