19.8 GBytes ROM disc readout using a 0.7 NA single objective lens and a violet laser diode

The performance of the proposed system with the noise reduced ROM optical storage disc and the error feedback (EF)-partial response maximum likelihood (PRML), composed of the error-select type adaptive equalizer and the adaptive Viterbi decoder, is demonstrated. The reproduced signal of the 19.8 GBytes ROM disc shows a sufficient low error characteristic.