Japanese LED maker Nichia Corporation has filed four provisional injunction actions in Tokyo District Court to enjoin Tsannkuen Japan (Sankun Nihon Denki Kabushiki Kaisha) from infringing Nichia's patent.

Nichia believed G.K. Seiyu and K.K. Yamada Denki, had infringed Nichia's white LED patents (No. 3724498, No. 3995011, No. 4109297, No. 4530094).