Taiwan's first tier producers of optical discs like CMC Magnetics, Ritek and Prodisc Technology are licensed to use Philips DVD+R technology, but second-tier and smaller producers are not licensed.
As Philips’ DVD+R patents also cover CD-R technology, there is some ambiguity about the DVD+R royalty claim. This is why disc makers are unwilling to pay the royalty, unlicensed Taiwan users explained.Source: DigiTimes
Although Philips has not yet taken legal proceedings, Taiwan optical disc makers that have received a warning from the company are watching to see how the situation develops.
In a related development, Philips lost a CD-R/RW patent suit in the US in March of this year against Taiwan makers, which means the company may have difficulty trying to claim royalty payments for its CD-R/RW patents.