Blackboard Inc. v. Desire2Learn Inc.: Federal Circuit finds means plus function claim in computer-related patent to be indefinite

This week the Federal Circuit issued a new ruling holding a computer-related “means-plus-function” claim indefinite where the specification did not adequately describe the structure or process used to perform the function. 

In  Blackboard Inc. v. Desire2Learn Inc. the Federal Circuit was asked to determine the validity of certain claims of U.S. Patent 6,988,138, which relates to an Internet-based educational support system.  The claims included elements written in “means plus function” format.  In particular, claim 1 required a “means for assigning a level of access to and control of each data file.”  When a limitation is written in means plus function format, the Court noted that 35 U.S.C. § 112, paragraph 6 limits the scope of the claim to “the corresponding structure . . . described in the specification and equivalents thereof.”

In Blackboard, the Court considered whether the specification included enough disclosure to describe the structure or function that performs the “means for assigning.”  The patent holder pointed out that the specification disclosed an “access control manager” that creates an “access control list.”  However, the Court found that:

what the patent calls an “access control manager” is simply an abstraction that describes the function of controlling access to course materials, which is performed by some undefined component of the system.  The ACM is essentially a black box that performs a recited function.  But how it does so is left undisclosed.

Thus, the Court found the claim to be indefinite because the “means for assigning” clause did not contain adequate disclosure of a corresponding structure or process. 

The Court’s decision includes a summary of its recent caselaw involving computer-related means plus function claims.  Specifically, the Court notes that in  Aristocrat Technologies Australia Pty. Ltd. v. International Gaming Technology:

we addressed the question of whether a general reference to ‘a standard microprocessor-based gaming machine with appropriate programming’ constituted a sufficient disclosure of structure to support a claimed function in a means-plus-function claim.  We concluded that it did not.

Discussing Net MoneyIN Inc. v. VeriSign Inc., the Court noted that

where a computer is referenced as support for a function in a means-plus-function claim, there must be some explanation of how the computer performs the claimed function.

Finally, referring to Finisar Finisar Corp. v. DirecTV Group, Inc. the Court stated that

Simply reciting “software” without providing some detail about the means to accomplish the function is not enough.


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