Aristocrat Technologies Australia Pty Ltd. v. International Game Technology
United States Court of Appeals for the Federal Circuit
521 F.3d 1328 (2008)
Aristocrat's (plaintiff) slot-machine patent claimed a "game control means" as a means-plus-function limitation, but its specification disclosed only a standard microprocessor capable of "appropriate programming" without describing any specific algorithm; the district court found the claims indefinite for lacking the required structural disclosure, and Aristocrat appealed, arguing a skilled artisan could easily devise a suitable algorithm.
Whether, under 35 U.S.C. § 112, paragraph 6, patent applicants with a means-plus-function limitation for a computer-related invention are required to disclose the algorithm that transforms the general purpose microprocessor to a special purpose computer programmed to perform the disclosed algorithm.