Taiyo Yuden filed a patent suit in the United States against two Taiwanese makers of DVD discs for violation of manufacturing technology for DVD-R discs. Taiyo Yuden filed a suit at a California district court against Prodisc Technology on Oct. 30 and Ritek on Nov. 21, Taiyo Yuden spokeswoman Rieko Kimoto said.

Taiyo Yuden said the two Taiwanese firms infringed three patents regarding the manufacturing process for recording functions of DVD-R and had refused to pay patent fees.