Federal Circuit Finds Means plus Function Element in Claim Indefinite Since Specification Did Not Describe Structure in Specification
In Blackboard, Inc. v. Desire2Learn Inc., 91 U.S.P.Q.2D 1481 (Fed. Cir. 2009), the Court of Appeals for the Federal Circuit (CAFC) deliberated on two issues raised by the respective parties on appeal from the United States District Court for the Eastern District of Texas. Specifically, Desire2Learn contested the district court’s holding of infringement of claims 36-38 of Blackboard’s U.S. Patent No. 6,988,138, which relates to an Internet-based educational support system and corresponding methods. In turn, Blackboard cross-appealed the District Court’s ruling, on summary judgment, that claims 1-35 of the ‘138 patent are indefinite.
Single login feature
Turning to the first issue, Desire2Learn argued that claims 36-38 do not include a “single login” limitation for the recited method of providing an online education system, and thus were anticipated by two prior art references. The ‘138 patent discloses a system that allows for online management of information relating to individual courses. Of particular benefit is the ability to allow a user to use a single login to access multiple courses with multiple respective roles in those courses (i.e., the “single login” limitation). For example, a graduate student who is a student in a first course and a teacher in a second course could use a single login to access both courses and access materials for both courses according to the corresponding role of the graduate student in the respective course.
Blackboard asserted that the “single login” feature is its patent’s essential improvement over prior art systems, and is recited in every claim including independent claim 36 (from which claims 37 and 38 depend).
Claim 36 recites:
An [sic] method for providing online education… comprising the steps of:
establishing that each user is capable of having redefined [sic: “predefined”] characteristics indicative of multiple predetermined roles in the system and each role providing a level of access to and control of a plurality of course files;
providing a predetermined level of access and control over the network to the course files to users with an established role as a student user enrolled in the course; and
providing a predetermined level of access and control over the network to the course files to users with an established role other than a student user enrolled in the course.
Though claim 36 does not explicitly provide for a single login, Blackboard argued that such a single login is required because the term “user” refers to an electronic user account that is defined by a single user name and password combination. Thus, the user being capable of having multiple roles is an electronic user having a single name and password combination, i.e., a single login.
For support, Blackboard pointed to the specification, which sometimes uses the word “user” to ostensibly refer to an electronic representation of a person. However, the Federal Circuit (Judges Bryson and Moore, andCudahyby designation) disagreed. Specifically, the Federal Circuit reasoned that the specification typically uses the term “user account” to refer to the electronic representation of the user. Moreover, aside from a few shorthand references, the specification also typically uses the term “user” to refer to a flesh-and-blood person. Also, of the four embodiments described in the specification, only one includes the single login feature. Therefore, the Federal Circuit found that specification does not require that the recited “user” necessarily refers to an electronic user in the context of a single login.
The Federal Circuit further reviewed other claims and noted the relationship between claim 1 of the ‘138 patent and claims 24 and 25 which depend from claim 1. While claim 1 includes the same pertinent language as claim 36, dependent claims 24 and 25 recite the single login limitation. Thus, the Federal Circuit reasoned that as claim 1 cannot be construed to require a single login without making claim 25 redundant, claim 36, too, does not require the single login. Therefore, in its decision, the Federal Circuit affirmed that a dependent claim adding a particular limitation gives rise to the presumption that the limitation is not present in the independent claim.
As a result, the Federal Circuit held that, as there was not recited single login feature, claims 36-38 were invalid for anticipation by prior art systems.
Turning now to the 35 U.S.C. 112 issue, Blackboard challenged the district court’s invalidation of claims 1-35 as indefinite. Referring to independent claim 1 as representative (claims 2-35 depend from claim 1), claim 1 includes four means-plus-function clauses, including “means for assigning a level of access to and control of each data file based on a user of the system’s predetermined role in a course.” As the limitation is written in means-plus-function form, it is construed to cover only the structure described in the specification and equivalents thereof, as prescribed by 35 U.S.C. 112, paragraph 6.
Blackboard argued that the structure performing the assigning function is a software feature known as the “access control manager” (ACM), which is described in only one paragraph of the specification:
Access control manager 151 creates an access control list (ACL) for one or more subsystems in response to a request from a subsystem to have its resources protected through adherence to an ACL. Education support system 100 provides multiple levels of access restrictions to enable different types of users to effectively interact with the system (e.g. access web pages, upload or download files, view grade information) while preserving confidentiality of information.
The Federal Circuit upheld the district court’s decision that claims 1-35 are indefinite, because the specification failed to sufficiently describe the means by which the ACM creates an ACL. In particular, the Federal Circuit decided that the lone paragraph describing the ACM does not describe a structure, but merely puts forth an abstraction defined only by a function. That is, “[t]he specification contains no description of the structure or the process that the access control manager uses to perform the ‘assigning’ function. Nor has Blackboard ever suggested that the ‘access control manager’ represents a particular structure defined other than as any structure that performs the recited function.”
Blackboard argued that reference to a general-purpose computer satisfies the requisite structural disclosure for the means-plus-function limitation. Citing Aristocrat Techs. Austl. PTY Ltd. V. Int’l Game Tech., 521 F.3d 1328, 1334 (Fed. Cir. 2008), the Federal Circuit countered that relying on a general structure is equivalent to saying “that the function is performed by a computer that is capable of performing the function.” Moreover, citing Net MoneyIN, Inc. v. VeriSign, Inc., 545 F.3d 1359, 1367 (Fed. Cir. 2008), the Court further noted that “when 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.” In other words, the Federal Circuit concluded that the specification only describes the function to be performed, but says nothing about how the ACM performs the function (i.e., how the ACM creates the ACL).
Blackboard also argued that the process of creating an ACL through software is well known to one of ordinary skill in the art. The Federal Circuit was unmoved by this argument, emphasizing that the question before it is not the ability of one of ordinary skill in the art, but whether the specification sufficiently describes a corresponding structure to a claimed means. In particular, the Court asserted that a patentee cannot avoid sufficiently disclosing a structure because someone of ordinary skill in the art could come up with a means to perform a claimed function. “That ordinarily skilled artisans could carry out the recited function in a variety of ways is precisely why claims written in ‘means-plus-function’ form must disclose the particular structure that is used to perform the recited function.”
Thus, in holding claims 1-35 to be indefinite, the Federal Circuit concluded that Blackboard is attempting to capture any possible means for performing the assigning function, in violation of 35 U.S.C. 112, by disclosing the means only as a general structure to perform the function.
Significance for Patent Applicants
As set forth below in the feature comment The Heightened Disclosure Requirement for Software Claimed Using Means-Plus-Function Limitations, when describing an invention which is realized using software, it is important that the specification provide a heightened level of detail. While there is no brightline test, this detail must be more than merely an indication that the particular module can be implemented using a general purpose computer. Instead, the patent applicant needs to provide details as to how the module operates or is constructed, possibly through the use of flowcharts. While seemingly limited to limitations relying on 35 U.S.C. 112 ¶6, it is possible that this logic could be extended to other types of functionally-described elements. Such a potential would appear to be higher during prosecution where the Examiner is entitled to take a broader interpretation of the claims, as demonstrated by the Board of Patent Appeals and Interferences in Ex parte Kenichi Miyazaki, 89 USPQ2d 1207 (BPAI 2008). Thus, while it is unlikely that levels of detail such as copies of source code would be required, when drafting applications which are being implemented using software, applicants need to ensure that the specification includes structural detail as to the implementation of the software modules.