Optical recording apparatus capable of changing the length of synchronization portions

1. An information recording method for recording information on a rewritable recording medium comprising the steps of:

recording synchronizing signal information in a synchronizing signal portion on the rewritable recording medium;

recording data information in a data portion of the rewritable recording medium after the synchronizing signal portion by forming marks in the data portion, wherein the marks for particular areas of the medium are different in a physical property from other areas of the medium so as to record data information in association with both ends of each of the marks; and

substantially randomly inverting the marks and spaces between the marks each time the information is recorded;

wherein upon rewriting of at least the recorded synchronizing signal information, a length of the synchronizing signal portion changes and a start position of the synchronizing signal portion changes, and wherein a change of the synchronizing signal information start position is smaller than a change of the length of the synchronizing signal portion.

2. An information recording method according to claim 1 , wherein the length of the synchronizing signal is randomly changed.

3. An information recording method according to claim 1 , wherein the synchronizing information start portion is randomly changed.

4. An information recording method according to claim 1 , wherein the information is recorded in a plurality of sectors, and the length of the synchronizing signal is changed at each sector.

5. An information recording method according to claim 1 , wherein an amount of shift of the synchronizing information start portion is substantially equal to a length of a mark within the synchronizing signal portion.

6. An information recording method according to claim 5 , wherein the amount of shift is substantially equal to ¼ byte.