Patent ID: 6445313
Filing Date: 2002-09-03
Classification: G11B,H03M

Abstract:
A data modulating method for an optical recording medium wherein a source data is converted under a fixed code conversion rate and a (d, k) constraint, the method comprising the steps of:preparing a first set of conversion tables where the source data is converted into a coded data, said first set of conversion tables including conversion tables for converting 2, 4, 6 and 8-bit data into 3, 6, 9 and 12-bit data respectively; preparing a second set of conversion tables for a specific source data to be converted into a coded data, said second set of conversion tables including conversion tables for converting 2 and 4-bit data into 3 and 6-bit data respectively; converting the source data into a first and a second bit stream of coded data using both of sets of the conversion tables; calculating a digital sum value for the first and second bit streams whenever the second coded data converted from the specific source data is found; selecting the coded data stream that has smaller digital sum value; and converting the selected code data stream into a channel data stream to be recorded on the optical recording medium, wherein the code conversion rate of the conversion tables is &frac23; such that source data of a 2, 4, 6 and 8-bit data are converted into a 3, 6, 9 and 12-bit data respectively, wherein the converted coded data stream maintains a (d, k) constraint of (1, 8), and wherein no merging bit is used between converted coded data.