Bloomberg reports that Konami, creator of the Dance Dance Revolution video game series, has sued Harmonix, claiming Rock Band violates its patents.

Konami's patents, issued in 2002 and 2003, relate to the simulation of musical instruments, a music-game system and a "musical-rhythm matching game". Konami is demanding cash compensation and wants an order to block Viacom and Harmonix from using the inventions.

Konami has its own Rock Band type game, Rock Revolution, planned for release later this year which it says will feature the most realistic drum controller on the market.