Friday, July 31, 2009

No software means plus function claims anymore

Blackboard's patent covers an internet-based educational support system and method. (U.S. Pat. No. 6,988,138). On summary judgment, the district court (Judge Clark, E.D. Tex.) found claims 1-35 invalid as indefinite, but a jury found found that Desire2Learn liable for infringement of claims 36-38. On appeal, the Federal Circuit agreed that Claims 1-35 are indefinite, and – after altering the claim construction – held that the remaining claims were also invalid as anticipated.
Means-Plus-Function: Blackboard's seemingly broadest claim (claim 1) includes several means-plus-function clauses, including a "means for assigning a level of access and control." The specification briefly discusses an "access control manager" (ACM) with an "access control list." On appeal, however, the court found that brief description to be an insufficient "disclosure of the structure that corresponds to the claimed function" and consequently indefinite under 35 U.S.C. §112 ¶2. See In re Donaldson, 16 F.3d 1189 (Fed. Cir. 1994)(en banc).
"[W]hat the patent calls the '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."
Important for patent drafter, means-plus-function claims require disclosure in the specification even if the means are already well known in the art.
The fact that an ordinarily skilled artisan might be able to design a program to create an access control list based on the system users' predetermined roles goes to enablement. The question before us is whether the specification contains a sufficiently precise description of the "corresponding structure" to satisfy section 112, paragraph 6, not whether a person of skill in the art could devise some means to carry out the recited function.
Because claims 2-35 all depend upon claim 1, they are all invalid as indefinite
Claim construction: At the trial, Blackboard's expert could only identify one difference between claims 36-38 and the prior art. Namely, that the Blackboard patent identified a "single login" feature that allowed one user to have various roles within the system. "For example, Blackboard asserted that its claimed method would allow a graduate student who was a student in one course and a teacher in another to use a single login to obtain access to both courses and to obtain access to the materials for each course according to the graduate student’s role in each." However, on appeal, the Federal Circuit determined that the claims do not actually require that feature -- leading them to hold the claims invalid based primarily on the admissions of Blackboard's own expert.
[O]nce the claims are properly construed, the conclusion of anticipation is dictated by the testimony of Blackboard’s own witnesses and the documentary evidence that was presented to the jury. Based on that evidence, and in the absence of a “single login” requirement in claims 36-38, it is clear that the prior art contains every limitation of those claims.Defendant Desire2Learn wins a complete victory (after a few million in attorney fees).