Information recording method and optical disk apparatus using same

Abstract

When record marks are recorded on a recording medium while making a code symbol '1' of data by obtained coding write information according to a coding system having no DC free property correspond to every edge of the record marks, the recording is effected while inserting resynchronizing signals into the write information with a constant interval. For the resynchronizing signal either one selected between a first resynchronizing code pattern, in which the number of symbols '1' contained therein is even, and a second resynchronizing code pattern, in which the number of symbols '1' is odd, so that an accumulated charge obtained from the run length of the coded data approaches zero is used. Each of the first and the second resynchronizing code pattern contains at least a specified pattern, which doesn't meet the coding rule. The selection is effected by adding a run length switching code to the resynchronizing signal and by switching it to '0' or '1' depending on an output of a run length measuring circuit and a run length judging circuit. In this way it is possible to suppress fluctuations in the level of a reproduced signal obtained from the record marks recorded on the recording medium and to realize a stable data detection by using the original waveform detection method, by which the reproduced signal is converted into a binary signal by using a suitable slice level.