Claim Construction Order

CBT Flint Partners, LLC v. Return Path, Inc. et al., Case No. 1:07-cv-01822 (N.D. Ga. July 10, 2008) (Thrash, Jr., J.)

Judge Thrash construed the claims of two patents relating to a method and system for hindering the proliferation of unsolicited email messages (i.e., “spam”).

Computer Implemented Means-Plus-Function Limitation Must be Supported in Specification by Specific Algorithm

Notably, the Court found that one of the asserted claims was invalid for indefiniteness and thus not amenable to claim construction. In particular, the Court found that the patent specification failed to disclose sufficient structure to support the following means-plus-function limitation: “means . . . for detecting an indication or an origin of an electronic mail communication . . . and for comparing the indication to an authorization list.” According to the Court, the structure identified in the specification that performs these claimed functions was “a computer or multiple computers in communication with each other.”

The Federal Circuit has established that the corresponding structure of a computer-implemented means-plus-function term is the algorithm for performing the function that is identified in the specification and equivalents. See WMS Gaming, Inc. v Int’l Game Tech., 184 F.3d 1339 (Fed. Cir. 1999) and Harris Corp. v. Ericsson Inc., 417 F.3d 1241 (Fed. Cir. 2005). More recently, the Federal Circuit stated that “this court has consistently required that the structure disclosed in the specification be more than simply a general purpose computer or microprocessor.” See Aristocrat Techs. Australia v. Int'l Game Tech., 521 F.3d 1328, 1333 (Fed. Cir. 2008) (affirming a finding of invalidity for failure to disclose any structure, i.e., any algorithm, to support a software means-plus-function claim).

Quoting extensively from Aristocrat, Judge Trash concluded that in order to claim the recited means “for detecting” and “for comparing,” the Plaintiff “must have disclosed the algorithm.” Finding that the specification disclosed no algorithm, but only general purpose computers as corresponding structure, the Court held that the asserted claim was invalid for indefiniteness.