Patent ID: 7016288
Filing Date: 2006-03-21
Classification: G11B

Abstract:
1. An information carrier comprising a recording area for writing patterns which represent user information and a header area comprising patterns which represent header information, said header area comprising a synchronization area comprising a predetermined synchronization pattern for synchronizing a clock frequency in a device in which the information carrier is used, characterized in that the predetermined synchronization pattern comprises a first part and a second part, the second part being distinguishable from the first part, characterized in that the predetermined synchronization pattern is composed of marks and of spaces between the marks, and in that the first part of the predetermined synchronization pattern contains marks having a first length and spaces having a second length whereas the second part of the synchronization pattern contains marks having a third length and spaces having a fourth length, the first length being different from the third length and the second length being different from the fourth length, in that the header information is converted into patterns in the header area according to a (d,k) Run Length Limited modulation code, in which d represents a predetermined natural number larger than zero and k represents a predetermined natural number larger than d, and the length of each mark and each space expressed as a number of channel bit lengths (T), and in that the first part of the predetermined synchronization pattern contains marks having a first length of (d+1) times the channel bit length, and spaces having a second length of (d+1) times the channel bit length, and the second part of the predetermined synchronization pattern contains marks having a third length of (k+1) times the channel bit length and spaces having a fourth length of (k+1) times the channel bit length, and in that the predetermined synchronization pattern also comprises a third part, which third part contains marks having a length of (k−d) times the channel bit length and spaces also having a length of (k−d) times the channel bit length.