Patent ID: 7800998

Claim:
An optical disk apparatus comprising: recording means for recording data on an optical disk by inserting synchronization information in every predetermined information unit; and synchronization information control means which sets a polarity of a first synchronization information of two successive synchronization information to a mark or a space such that a Digital Sum Value is minimized and which sets a polarity of a second synchronization information to a mark or a space in accordance with the polarity of said first synchronization information; and, when the polarity of said first synchronization information is a mark, said synchronization information control means sets the polarity of said second synchronization information to a polarity at which said Digital Sum Value is minimized and sets the polarity of a next synchronization information to a mark; and, when the polarity of said first synchronization information is a space, said synchronization information control means always sets the polarity of said second synchronization information to a mark.