Essentially, means-plus-function claiming allows the drafter to claim the invention based on functionality rather than the more traditional (and preferred) claim technique that describes structure(s) within the body of the claim itself.
A claim term is functional when it recites a feature by what it does rather than by what it is. There is nothing intrinsically wrong with the use of such claim language, although it is becoming more and more apparent (if it wasn’t already apparent enough) that the Federal Circuit frowns upon means-plus-function claiming.
Nevertheless, § 112(f) expressly authorizes a form of functional claiming (means-plus-function claiming). The statute says:
An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
The basic law relative to § 112(f) explains that a decision on whether a claim is indefinite requires a determination of whether those skilled in the art would understand what is claimed when the claim is read in light of the specification. However, no structure in the specification means the person of skill in the art cannot save the disclosure by understanding.
Means-plus-function claiming has raised its ugly head again over the past year with respect to claims covering software. For example, in Noah Systems, Inc. v. Intuit, Inc. and Ergo Licensing, LLC v. CareFusion 303, Inc the outcome rested upon whether means-plus-function claims in a software patent were indefinite and, therefore, invalid. Both cases followed the ever-growing body of law on the topic from the Federal Circuit, which requires an algorithm to be presented in the disclosure in order to satisfy the disclosure requirements. In both cases, the claims were lost.
The Federal Circuit has pointed out that means-plus-function claiming involves a quid pro quo. In exchange for being able to draft a claim limitation in purely functional language, the applicant must describe in the patent specification some structure which performs the specified function. Importantly, the functional claim language covers only the corresponding structure, material, or acts described in the specification and equivalents thereof, which confines the breadth of protection otherwise permitted by purely functional claiming.
The Federal Circuit also acknowledged that it is undisputed that the question of whether a claim is indefinite is based on how the claim limitation would be understood by one of skill in the art. Notwithstanding, the Court went on to say, however, that the testimony of one of ordinary skill in the art cannot supplant the total absence of structure from the specification. These two statements seem logically inconsistent. If someone of skill in the art would understand, then how could you conclude there is a total absence of structure in the specification?
In any event, the Federal Circuit has explained that the law regarding special-purpose computer-implemented means-plus-functions claims is divided into two distinct groups: (1) cases where the specification discloses no algorithm; and (2) cases where the specification does disclose an algorithm but a defendant contends that disclosure is inadequate. The distinction is important because if an algorithm is disclosed, then it matters what one of skill in the art would understand. If no algorithm is disclosed (or as a result of this case, if a partial algorithm is disclosed), it is irrelevant whether one of skill in the art would understand the disclosure.
It is easy to envision a day when this requirement is applied across the board in software patent cases. In fact, many notable academics are already urging courts to do just that. Thus, it is best practice to seek to satisfy this new, much stricter disclosure requirement. By so doing, you have opened up another avenue of claims that can be pursued, and you have created a much stronger patent application that will support numerous patent claims and can legitimately be the foundation of a patent portfolio moving forward.
Thus, flow charts, pseudo code or even software code that describes the routines and subroutines can and should be included in what you file when you file a patent application that relates to software.
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