(Received September 20, 2005; revised January 21, 2006; accepted February 15, 2006; published online May 9, 2006)
Multilevel run-length-limited (ML-RLL) recording technology is employed to increase the capacity of the read-only disc with no change on optical or mechanical units. 4L-RLL recording on read-only disc has been implemented with minimum recorded mark length same as that in conventional digital versatile disc (DVD). The capacity of a double layer DVD disc with 4L-RLL (2, 10) modulation reaches 15 GB. Experimental results show that the ratio of the standard deviation of noise to the dynamic range of readout signal amplitude is lower than 4.53%, which means that the requirement of signal detection for 4L-RLL can be satisfied.
KEYWORDS:multi-level recording, read-only disc, dynamic range, run-length-limited, PRML