| 摘要 |
PURPOSE: To increase the recording density even though a recording is of an PPM recording by performing a recording on a recording medium with a modulation system in which at least either '1' or '0' is not continued in clocks equal to or longer than two clocks and reproducing the medium with a partial response PR. CONSTITUTION: The part of (C) is a part in which an original signal Din continues like 100010001000.... In this state, reproducing output variations are required, for the first time, to be changed in between adjacent two values (a level B and a level C) by making 4 clock timings a cycle. This means that it is sufficient that the resolution of a reproducing beam is secured with respect to recording marks making clock timings equal to or longer than 4 clock timings a cycle. Therefore, even though the recording is of the PPM recording, a recording density equal to a so-called PWM recording is realized. |
