| 摘要 |
PURPOSE:To increase the recording density, by giving 0 between bits between 1 and 1 by >=2 bits, through the three position modulation (3PM) for a binary data word and the provision of a specified secondary conversion in accordance with the state of consecution of the data words. CONSTITUTION:Binary data words W0-W7 in 3-bit or the like are processed for 3PM to be converted into code words P1P2P3P4P5P6, in which the 6-th bit is 0, at least one set of 1 is included, and which is 6-bit having >=2 bits between bits of 1. In a code train arranging such a code word in series, if 101 is generated over adjacent code words, when the secondary conversion is made so that the bits are inverted into 010, a code train having >=2 bits is given between bits of binary 1. Thus, the recording density can be increased in digital magnetic recording and reproduction surely and easily through the use of this digital modulation and demodulation system. |
