Tsannkuen Japan, a subsidiary of a Taiwanese company, has involved in infringing Nichia's patent (No. 4530094, or "094 patent") and Nichia claims damages for the infringement with regard to LED light bulbs manufactured by Tsann Kuen.

According to Nichia, it has filed two patent infringement lawsuits at the Tokyo District Court with Tsann Kuen as the defendant and Unity Opto Technology Co. Ltd., as its supporting intervener.

In addition, Nichia also confirmed that Tsann Kuen sold LED light bulbs with E17 bases (product number: TK-BE05L, TK-BE05N), and upon their understanding that the light bulbs also infringed 094 patent, it commenced another lawsuit as to these light bulbs for the enjoinment of infringing acts and to claim damages based on this patent.