| 摘要 |
PURPOSE: To provide a binary coding method which is capable of detecting the presence or absence of an alteration by assigning either one of binary code signals 0 and 1 to either one of binary code signals 011, 110 and 101 and recording the signals in a unrewritable recording medium. CONSTITUTION: The binary code of a character (a) is expressed as 01100001 according to the 8-bit code stipulated in an ANSI. In the same way, the binary code of a character (b) is 01100010 and the binary code of a character (c) is 01100011. In these binary codes, 011 is assigned to 0 and 110 is assigned to 1, and codings are performed. The coded signals generated as a result become 011110110011...011110110. These signals are recorded in an unrewritable recording medium. As for a recording state, the state for only a B part where 1-bit is recorded changes (a black-painted change in this case) and the state for a part W where 0-bit is recorded does not change, as shown in (d), for instance. |
