Ricoh Co. said Wednesday it has dropped its patent infringement lawsuits against Taiwanese companies because settlements have been reached.

The maker of automated office equipment filed the suits in May and September 2004 against major disk manufacturer Lite-ON IT Corp. and its four affiliates in a U.S. district court, claiming the defendants infringed on a total of six patents concerning CD and DVD technologies Ricoh owns in the United States.

Without elaborating, Ricoh said it has granted the companies licenses for the patents.

The move came after Ricoh dropped similar lawsuits in December in the United States against other companies, including CMC Magnetics Corp., another major Taiwanese disk maker.