IP Alerts

IP Alert
IP Alert: Federal Circuit Provides Guidance Regarding Means-Plus-Function "Structure"

November 7, 2011

In a decision handed down on November 4, 2011, in Typhoon Touch Technologies, Inc. v. Dell Inc., the Federal Circuit provides further guidance on what constitutes sufficient “structure” to support a means-plus-function claim recitation.

So-called “functional” claiming is permissible, but carries with it certain requirements under U.S. patent law. Unlike elsewhere in the world, a “means”-based claim recitation in the U.S. is typically understood to refer to the structure that performs the claimed function, as described by the applicant in the patent application. This understanding is based upon 35 U.S.C. 112, 6th paragraph, which reads as follows:

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.

Such a requirement at least implicitly requires that there actually be “structure, material, or acts” described in the patent application to support the use of a “means”-based claim. Some recent decisions from the Court of Appeals for the Federal Circuit have made it clear that this need for “structure” can exceed the usual requirements for enablement and an adequate written description.

In Aristocrat Technologies Australia Pty Ltd. v. International Game Technology, for example, the Federal Circuit acknowledged that while the specification at issue provided sufficient enablement and written description to support the claims, that patent application nevertheless lacked sufficient description of the structure that would accomplish the “game control means” of the claims. In particular, the patent application did not describe an algorithm that could be employed by a computer to cause that computer to be such a “game control means.” As a result, the Aristocrat court held the resultant patent invalidly granted.

The recent decision in Typhoon Touch Technologies, Inc. v. Dell Inc. provides additional guidance in this area of practice. Here, the Federal Circuit overturned a decision by the U.S. District Court for the Eastern District of Texas that a patent application lacked sufficient structure for the claim recitation “means for cross-referencing.” In reaching its decision, the Federal Circuit noted that a patent application need not include the actual computer code that would accomplish such a function, nor are flow charts or the like required (though such presentations could, in and of themselves, potentially satisfy the “structure” requirement). Instead, an algorithm to accomplish the claimed functionality could also be presented as prose within the text of the specification.

In particular, citing Finisar Corp. v. DirecTV Group, Inc., the court reasoned that “Precedent and practice permit a patentee to express that procedural algorithm ‘in any understandable terms including as a mathematical formula, in prose, or as a flow chart, or in any other manner that provides sufficient structure.’” Analysis of the applicant’s specification text in the present case convinced the court that the patent application in question adequately expressed, in prose, an algorithm to carry out the claimed cross-referencing function. Accordingly, the court reversed the district court’s contrary conclusions in these regards.

If you have any questions regarding this decision, please contact Fitch Even partner Steven G. Parmelee, the author of this alert.

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