The Grammar Secret: the Article “a” Still Signifies ‘One or More,’ but Requires a Single Component Executing All Functions”

In Salazar v. AT&T Mobility LLC, the Federal Circuit held that the wording “a microprocessor” does not require there to be only one microprocessor in an open ended claim; however, subsequent limitations referring to “said microprocessor” require at least one microprocessor to be capable of performing every one of the claimed functions. The claim in question recited:

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, for transmission to said external devices wherein each communication protocol includes a command code set that defines the signals that are employed to communicate with each one of said external devices;
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, such that the memory space required to store said parameters is smaller than the memory space required to store said command code sets;
a user interface coupled to said microprocessor for sending a plurality of signals corresponding to user selections to said microprocessor and displaying a plurality of menu selections available for the user’s choice, said microprocessor generating a communication protocol in response to said user selections; and
an infra-red frequency transceiver coupled to said microprocessor for transmitting to said external devices and receiving from said external devices, infra-red frequency signals in accordance with said communications protocols.

The dispute between the parties centered around whether the claims necessitate only a single microprocessor capable of performing all of the “generating,” “creating,” “retrieving,” and “generating” functions identified in the claim. The district court responded in the affirmative and interpreted the term “a microprocessor” to mean “one or more microprocessors, at least one of which is configured to perform all of the generating, creating, retrieving, and generating functions.” Salazar contested the district court’s verdict, arguing that the claim terms should have been interpreted to require one or more microprocessors, with any one of them capable of performing each of the “generating,” “creating,” and “retrieving” functions specified in the claims.

After meticulously examining its previous rulings, the Federal Circuit backed the district court’s verdict that even though the term “a microprocessor” does not exclusively demand the presence of a single microprocessor, the restrictions mentioned in the claim that link back to “said microprocessor” necessitate involvement of at least one microprocessor able to execute each and every one of the claimed functions. The Court likened this case to the scenario where a dog owner wishes to have “a dog that rolls over and fetches sticks,” in which utilizing two dogs, each trained in performing only one task, would not be enough.

Practice Tips:
The Federal Circuit has acknowledged that there are exceptions to the general rule when it comes to patent claims. One such exception is when the claims are unambiguous, or when the patent owner provides a clear definition of the terms used in the patent application. As a result, if practitioners wish to avoid the interpretation that a single processor must carry out all the functions mentioned in the claim, they must explicitly state this in their claim and make it apparent in the specification. In other words, it’s crucial to be clear and precise in the language used in the patent to avoid any ambiguity or misinterpretation. One such exemplary claim and boilerplate for the specification is reproduced below.

Claims
1. A device comprising:
a processor,
a memory storing executable instructions which we executed by the processor causes the processor alone or in combination with other processors to perform the following functions:
function a;
function b; and
function c.

Specification
An element preceded by “a” or “an” does not, without further constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element. Furthermore, subsequent limitations referring back to “said element” or “the element” performing certain functions signifies that “said element” or “the element” alone or in combination with additional identical elements in the process, method, article or apparatus are capable of performing all of the recited functions.