More than a year after guitar manufacturer Gibson first informed Guitar Hero publisher Activision it may be infringing a Gibson patent, a California U.S. District Court has dismissed the accusation. Gibson's patent, U.S. Patent No. 5,990,405, describes a "System and Method For Generating and Controlling a Simulated Musical Experience," and is intended to involve the user playing an actual musical instrument, accompanied by a backing track and prerecorded visuals. After unsuccessfully attempting to convince Activision to license the patent, Activision filed a complaint of non-infringement against Gibson. This alleged that not only do Guitar Hero's systems and peripherals not fall under the domain of the patent, but Gibson had for years allowed and encouraged the sale of Guitar Hero products without complaint. In fact, a number of official Guitar Hero controllers have borne the Gibson logo. As reported by the Los Angeles Intellectual Property Trademark Attorney Blog, the court determined that "Gibson's doctrine of equivalents arguments border on the frivolous," painting a clear distinction between the "actual operation of a musical instrument" as specified in the patent, and the interactions in Guitar Hero. Assigning equivalency, the court said, would open up similar accusations to the use of a "button of a DVD remote" or "a pencil tapping a table." "As a general observation, no reasonable person of ordinary skill in the relevant arts would interpret the '405 Patent as covering interactive video games," reads the ruling.