Source "Konami Corp., the Japanese creator of the ``Dance Dance Revolution'' music video game, sued Viacom Inc.'s Harmonix studio, claiming its ``Rock Band'' game violates patents. The Konami patents, issued in 2002 and 2003, relate to simulated musical instruments, a music-game system and a ``musical-rhythm matching game.'' Konami also makes the ``Karaoke Revolution'' music game with microphones, as well as the ``Metal Gear Solid'' espionage game. ``Rock Band,'' the game in which players emulate rock and rollers with toy instruments, drove a 16 percent increase in first-quarter revenue at New York-based Viacom's media networks business. Konami's Digital Entertainment unit said in May it plans to begin selling its own rock band game, called ``Rock Revolution,'' later this year. Konami is demanding cash compensation, plus an order that would block Viacom and Harmonix from using the inventions, according to the complaint, filed yesterday in federal court in Marshall, Texas. The suit names Harmonix Music Systems, Viacom, and Viacom's MTV Networks Co., which owns Harmonix. Viacom spokeswoman Kelly McAndrew said the company hasn't received the complaint, so had no immediate comment. " I wondered how long it would take them to do this, though it does seem to be a bit late. Also what about Activision who popularised the guitar genre with Guitar Hero? They've already had six titles released since 2005.